[RFC] [PATCH 0/6] Add camera support to the OMAP1 Amstrad Delta videophone

[RFC] [PATCH 0/6] Add camera support to the OMAP1 Amstrad Delta videophone

[Janusz Krzysztofik]

This series consists of the following patches:

  1/6	SoC Camera: add driver for OMAP1 camera interface
  2/6	OMAP1: Add support for SoC camera interface
  3/6	SoC Camera: add driver for OV6650 sensor
  4/6	SoC Camera: add support for g_parm / s_parm operations
  5/6	OMAP1: Amstrad Delta: add support for on-board camera
  6/6	OMAP1: Amstrad Delta: add camera controlled LEDS trigger

 arch/arm/mach-omap1/board-ams-delta.c     |   69 +
 arch/arm/mach-omap1/devices.c             |   43
 arch/arm/mach-omap1/include/mach/camera.h |    8
 drivers/media/video/Kconfig               |   20
 drivers/media/video/Makefile              |    2
 drivers/media/video/omap1_camera.c        | 1656 ++++++++++++++++++++++++++++++
 drivers/media/video/ov6650.c              | 1336 ++++++++++++++++++++++++
 drivers/media/video/soc_camera.c          |   18
 include/media/omap1_camera.h              |   16
 include/media/v4l2-chip-ident.h           |    1
 10 files changed, 3169 insertions(+)

Thanks,
Janusz

[RFC] [PATCH 1/6] SoC Camera: add driver for OMAP1 camera interface

[Janusz Krzysztofik]

This is a V4L2 driver for TI OMAP1 SoC camera interface.

Two versions of the driver are provided, using either videobuf-dma-contig or 
videobuf-dma-sg. The former uses less processing power, but often fails to 
allocate contignuous buffer memory. The latter is free of this problem, but 
generates tens of DMA interrupts per frame. Both versions work stable for me, 
even under heavy load, on my OMAP1510 based Amstrad Delta videophone, that is 
the oldest, least powerfull OMAP1 implementation.

The interface generally works in pass-through mode. Since input data byte 
endianess can be swapped, it provides up to two v4l2 pixel formats per each of 
several soc_mbus formats that have their swapped endian counterparts.

Boards using this driver can provide it with the followning information:
- if and what freqency clock is expected by an on-board camera sensor,
- what is the maximum pixel clock that should be accepted from the sensor,
- what is the polarity of the sensor provided pixel clock,
- if the interface GPIO line is connected to a sensor reset/powerdown input 
  and what is the input polarity.

Created and tested against linux-2.6.35-rc3 on Amstrad Delta.

Signed-off-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
---
 drivers/media/video/Kconfig        |   14
 drivers/media/video/Makefile       |    1
 drivers/media/video/omap1_camera.c | 1656 +++++++++++++++++++++++++++++++++++++
 include/media/omap1_camera.h       |   16
 4 files changed, 1687 insertions(+)

--- linux-2.6.35-rc3.orig/include/media/omap1_camera.h	1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.35-rc3/include/media/omap1_camera.h	2010-07-18 01:31:57.000000000 +0200
@@ -0,0 +1,16 @@
+#ifndef __MEDIA_OMAP1_CAMERA_H_
+#define __MEDIA_OMAP1_CAMERA_H_
+
+#define OMAP1_CAMERA_IOSIZE		0x1c
+
+struct omap1_cam_platform_data {
+	unsigned long camexclk_khz;
+	unsigned long lclk_khz_max;
+	unsigned long flags;
+};
+
+#define OMAP1_CAMERA_LCLK_RISING	BIT(0)
+#define OMAP1_CAMERA_RST_LOW		BIT(1)
+#define OMAP1_CAMERA_RST_HIGH		BIT(2)
+
+#endif /* __MEDIA_OMAP1_CAMERA_H_ */
--- linux-2.6.35-rc3.orig/drivers/media/video/Kconfig	2010-06-26 15:55:29.000000000 +0200
+++ linux-2.6.35-rc3/drivers/media/video/Kconfig	2010-07-02 04:12:02.000000000 +0200
@@ -962,6 +962,20 @@ config VIDEO_SH_MOBILE_CEU
 	---help---
 	  This is a v4l2 driver for the SuperH Mobile CEU Interface
 
+config VIDEO_OMAP1
+	tristate "OMAP1 Camera Interface driver"
+	depends on VIDEO_DEV && ARCH_OMAP1 && SOC_CAMERA
+	select VIDEOBUF_DMA_CONTIG if !VIDEO_OMAP1_SG
+	---help---
+	  This is a v4l2 driver for the TI OMAP1 camera interface
+
+if VIDEO_OMAP1
+config VIDEO_OMAP1_SG
+	bool "Scatter-gather mode"
+	depends on VIDEO_OMAP1 && EXPERIMENTAL
+	select VIDEOBUF_DMA_SG
+endif
+
 config VIDEO_OMAP2
 	tristate "OMAP2 Camera Capture Interface driver"
 	depends on VIDEO_DEV && ARCH_OMAP2
--- linux-2.6.35-rc3.orig/drivers/media/video/Makefile	2010-06-26 15:55:29.000000000 +0200
+++ linux-2.6.35-rc3/drivers/media/video/Makefile	2010-06-26 17:28:09.000000000 +0200
@@ -165,6 +165,7 @@ obj-$(CONFIG_VIDEO_MX1)			+= mx1_camera.
 obj-$(CONFIG_VIDEO_MX3)			+= mx3_camera.o
 obj-$(CONFIG_VIDEO_PXA27x)		+= pxa_camera.o
 obj-$(CONFIG_VIDEO_SH_MOBILE_CEU)	+= sh_mobile_ceu_camera.o
+obj-$(CONFIG_VIDEO_OMAP1)		+= omap1_camera.o
 
 obj-$(CONFIG_ARCH_DAVINCI)		+= davinci/
 
--- linux-2.6.35-rc3.orig/drivers/media/video/omap1_camera.c	1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.35-rc3/drivers/media/video/omap1_camera.c	2010-07-18 01:32:48.000000000 +0200
@@ -0,0 +1,1656 @@
+/*
+ * V4L2 SoC Camera driver for OMAP1 Camera Interface
+ *
+ * Copyright (C) 2010, Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
+ *
+ * Based on V4L2 Driver for i.MXL/i.MXL camera (CSI) host
+ * Copyright (C) 2008, Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
+ * Copyright (C) 2009, Darius Augulis <augulis.darius@gmail.com>
+ *
+ * Based on PXA SoC camera driver
+ * Copyright (C) 2006, Sascha Hauer, Pengutronix
+ * Copyright (C) 2008, Guennadi Liakhovetski <kernel@pengutronix.de>
+ *
+ * Hardware specific bits initialy based on former work by Matt Callow
+ * drivers/media/video/omap/omap1510cam.c
+ * Copyright (C) 2006 Matt Callow
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+
+#include <linux/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/version.h>
+
+#include <media/omap1_camera.h>
+#include <media/soc_camera.h>
+#include <media/soc_mediabus.h>
+#ifndef CONFIG_VIDEO_OMAP1_SG
+#include <media/videobuf-dma-contig.h>
+#else
+#include <media/videobuf-dma-sg.h>
+#endif
+
+#include <plat/dma.h>
+
+
+#define DRIVER_NAME		"omap1-camera"
+#define VERSION_CODE		KERNEL_VERSION(0, 0, 1)
+
+
+/*
+ * ---------------------------------------------------------------------------
+ *  OMAP1 Camera Interface registers
+ * ---------------------------------------------------------------------------
+ */
+
+#define REG_CTRLCLOCK		0x00
+#define REG_IT_STATUS		0x04
+#define REG_MODE		0x08
+#define REG_STATUS		0x0C
+#define REG_CAMDATA		0x10
+#define REG_GPIO		0x14
+#define REG_PEAK_COUNTER	0x18
+
+/* CTRLCLOCK bit shifts */
+#define LCLK_EN			BIT(7)
+#define DPLL_EN			BIT(6)
+#define MCLK_EN			BIT(5)
+#define CAMEXCLK_EN		BIT(4)
+#define POLCLK			BIT(3)
+#define FOSCMOD_SHIFT		0
+#define FOSCMOD_MASK		(0x7 << FOSCMOD_SHIFT)
+#define FOSCMOD_12MHz		0x0
+#define FOSCMOD_6MHz		0x2
+#define FOSCMOD_9_6MHz		0x4
+#define FOSCMOD_24MHz		0x5
+#define FOSCMOD_8MHz		0x6
+
+/* IT_STATUS bit shifts */
+#define DATA_TRANSFER		BIT(5)
+#define FIFO_FULL		BIT(4)
+#define H_DOWN			BIT(3)
+#define H_UP			BIT(2)
+#define V_DOWN			BIT(1)
+#define V_UP			BIT(0)
+
+/* MODE bit shifts */
+#define RAZ_FIFO		BIT(18)
+#define EN_FIFO_FULL		BIT(17)
+#define EN_NIRQ			BIT(16)
+#define THRESHOLD_SHIFT		9
+#define THRESHOLD_MASK		(0x7f << THRESHOLD_SHIFT)
+#define DMA			BIT(8)
+#define EN_H_DOWN		BIT(7)
+#define EN_H_UP			BIT(6)
+#define EN_V_DOWN		BIT(5)
+#define EN_V_UP			BIT(4)
+#define ORDERCAMD		BIT(3)
+
+#define IRQ_MASK		(EN_V_UP | EN_V_DOWN | EN_H_UP | EN_H_DOWN | \
+				 EN_NIRQ | EN_FIFO_FULL)
+
+/* STATUS bit shifts */
+#define HSTATUS			BIT(1)
+#define VSTATUS			BIT(0)
+
+/* GPIO bit shifts */
+#define CAM_RST			BIT(0)
+
+/* end of OMAP1 Camera Interface registers */
+
+
+#define SOCAM_BUS_FLAGS	(SOCAM_MASTER | \
+			SOCAM_HSYNC_ACTIVE_HIGH | SOCAM_VSYNC_ACTIVE_HIGH | \
+			SOCAM_PCLK_SAMPLE_RISING | SOCAM_PCLK_SAMPLE_FALLING | \
+			SOCAM_DATA_ACTIVE_HIGH | SOCAM_DATAWIDTH_8)
+
+
+#define CAM_EXCLK_6MHz		 6000000
+#define CAM_EXCLK_8MHz		 8000000
+#define CAM_EXCLK_9_6MHz	 9600000
+#define CAM_EXCLK_12MHz		12000000
+#define CAM_EXCLK_24MHz		24000000
+
+
+#define FIFO_SIZE		((THRESHOLD_MASK >> THRESHOLD_SHIFT) + 1)
+#define FIFO_SHIFT		__fls(FIFO_SIZE)
+
+#define DMA_BURST_SHIFT		(1 + OMAP_DMA_DATA_BURST_4)
+#define DMA_BURST_SIZE		(1 << DMA_BURST_SHIFT)
+
+#define DMA_ELEMENT_SHIFT	OMAP_DMA_DATA_TYPE_S32
+#define DMA_ELEMENT_SIZE	(1 << DMA_ELEMENT_SHIFT)
+
+#ifndef CONFIG_VIDEO_OMAP1_SG
+#define DMA_FRAME_SHIFT		(FIFO_SHIFT - 1)
+#define MIN_BUF_COUNT		3
+#else
+#define DMA_FRAME_SHIFT		DMA_BURST_SHIFT
+#define MIN_BUF_COUNT		2
+#endif
+
+#define DMA_FRAME_SIZE		(1 << DMA_FRAME_SHIFT)
+#define DMA_SYNC		OMAP_DMA_SYNC_FRAME
+#define THRESHOLD_LEVEL		DMA_FRAME_SIZE
+
+
+#define MAX_VIDEO_MEM		4	/* arbitrary video memory limit in MB */
+
+
+/*
+ * Structures
+ */
+
+/* buffer for one video frame */
+struct omap1_cam_buf {
+	struct videobuf_buffer		vb;
+	enum v4l2_mbus_pixelcode	code;
+	int				inwork;
+#ifdef CONFIG_VIDEO_OMAP1_SG
+	struct scatterlist		*sgbuf;
+	int				sgcount;
+	int				bytes_left;
+	enum videobuf_state		result;
+#endif
+};
+
+struct omap1_cam_dev {
+	struct soc_camera_host		soc_host;
+	struct soc_camera_device	*icd;
+	struct clk			*clk;
+
+	unsigned int			irq;
+	void __iomem			*base;
+
+	int				dma_ch;
+
+	struct omap1_cam_platform_data	*pdata;
+	struct resource			*res;
+	unsigned long			pflags;
+	unsigned long			camexclk;
+
+	struct list_head		capture;
+
+	spinlock_t			lock;
+
+	/* Pointers to DMA buffers */
+	struct omap1_cam_buf		*active;
+	struct omap1_cam_buf		*ready;
+
+	u32			reg_cache[OMAP1_CAMERA_IOSIZE / sizeof(u32)];
+};
+
+
+void cam_write(struct omap1_cam_dev *pcdev, u16 reg, u32 val)
+{
+	pcdev->reg_cache[reg / sizeof(u32)] = val;
+	__raw_writel(val, pcdev->base + reg);
+}
+
+int cam_read(struct omap1_cam_dev *pcdev, u16 reg, bool from_cache)
+{
+	return !from_cache ? __raw_readl(pcdev->base + reg) :
+			pcdev->reg_cache[reg / sizeof(u32)];
+}
+
+#define CAM_READ(pcdev, reg) \
+		cam_read(pcdev, REG_##reg, 0)
+#define CAM_WRITE(pcdev, reg, val) \
+		cam_write(pcdev, REG_##reg, val)
+#define CAM_READ_CACHE(pcdev, reg) \
+		cam_read(pcdev, REG_##reg, 1)
+
+/*
+ *  Videobuf operations
+ */
+static int omap1_videobuf_setup(struct videobuf_queue *vq, unsigned int *count,
+		unsigned int *size)
+{
+	struct soc_camera_device *icd = vq->priv_data;
+	int bytes_per_line = soc_mbus_bytes_per_line(icd->user_width,
+			icd->current_fmt->host_fmt);
+
+	if (bytes_per_line < 0)
+		return bytes_per_line;
+
+	*size = bytes_per_line * icd->user_height;
+
+	if (!*count || *count < MIN_BUF_COUNT)
+		*count = MIN_BUF_COUNT;
+
+	if (*size * *count > MAX_VIDEO_MEM * 1024 * 1024)
+		*count = (MAX_VIDEO_MEM * 1024 * 1024) / *size;
+
+	dev_dbg(icd->dev.parent,
+			"%s: count=%d, size=%d\n", __func__, *count, *size);
+
+	return 0;
+}
+
+static void free_buffer(struct videobuf_queue *vq, struct omap1_cam_buf *buf)
+{
+	struct videobuf_buffer *vb = &buf->vb;
+#ifdef CONFIG_VIDEO_OMAP1_SG
+	struct videobuf_dmabuf *dma = videobuf_to_dma(vb);
+#endif
+
+	BUG_ON(in_interrupt());
+
+	videobuf_waiton(vb, 0, 0);
+#ifndef CONFIG_VIDEO_OMAP1_SG
+	videobuf_dma_contig_free(vq, vb);
+#else
+	videobuf_dma_unmap(vq, dma);
+	videobuf_dma_free(dma);
+#endif
+
+	vb->state = VIDEOBUF_NEEDS_INIT;
+}
+
+static int omap1_videobuf_prepare(struct videobuf_queue *vq,
+		struct videobuf_buffer *vb, enum v4l2_field field)
+{
+	struct soc_camera_device *icd = vq->priv_data;
+	struct omap1_cam_buf *buf = container_of(vb, struct omap1_cam_buf, vb);
+	int bytes_per_line = soc_mbus_bytes_per_line(icd->user_width,
+			icd->current_fmt->host_fmt);
+	int ret;
+
+	if (bytes_per_line < 0)
+		return bytes_per_line;
+
+	WARN_ON(!list_empty(&vb->queue));
+
+	BUG_ON(NULL == icd->current_fmt);
+
+	buf->inwork = 1;
+
+	if (buf->code != icd->current_fmt->code ||
+			vb->width  != icd->user_width ||
+			vb->height != icd->user_height ||
+			vb->field  != field) {
+		buf->code  = icd->current_fmt->code;
+		vb->width  = icd->user_width;
+		vb->height = icd->user_height;
+		vb->field  = field;
+		vb->state  = VIDEOBUF_NEEDS_INIT;
+	}
+
+	vb->size = bytes_per_line * vb->height;
+
+	if (vb->baddr && vb->bsize < vb->size) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (vb->state == VIDEOBUF_NEEDS_INIT) {
+		ret = videobuf_iolock(vq, vb, NULL);
+		if (ret)
+			goto fail;
+
+		vb->state = VIDEOBUF_PREPARED;
+	}
+	buf->inwork = 0;
+
+	return 0;
+fail:
+	free_buffer(vq, buf);
+out:
+	buf->inwork = 0;
+	return ret;
+}
+
+static void set_dma_dest_params(int dma_ch, struct omap1_cam_buf *buf)
+{
+#ifndef CONFIG_VIDEO_OMAP1_SG
+	dma_addr_t dma_addr = videobuf_to_dma_contig(&buf->vb);
+	unsigned int block_size = buf->vb.size;
+#else
+	dma_addr_t dma_addr;
+	unsigned int block_size;
+
+	if (WARN_ON(!buf->sgbuf)) {
+		buf->result = VIDEOBUF_ERROR;
+		return;
+	}
+	dma_addr = sg_dma_address(buf->sgbuf);
+	if (WARN_ON(!dma_addr)) {
+		buf->sgbuf = NULL;
+		buf->result = VIDEOBUF_ERROR;
+		return;
+	}
+	block_size = sg_dma_len(buf->sgbuf);
+	if (WARN_ON(!block_size)) {
+		buf->sgbuf = NULL;
+		buf->result = VIDEOBUF_ERROR;
+		return;
+	}
+	if (unlikely(buf->bytes_left < block_size))
+		block_size = buf->bytes_left;
+	if (WARN_ON(dma_addr & (DMA_FRAME_SIZE * DMA_ELEMENT_SIZE - 1))) {
+		dma_addr = ALIGN(dma_addr, DMA_FRAME_SIZE * DMA_ELEMENT_SIZE);
+		block_size &= ~(DMA_FRAME_SIZE * DMA_ELEMENT_SIZE - 1);
+	}
+	buf->bytes_left -= block_size;
+	buf->sgcount++;
+#endif
+	omap_set_dma_dest_params(dma_ch, OMAP_DMA_PORT_EMIFF,
+			OMAP_DMA_AMODE_POST_INC, dma_addr, 0, 0);
+	omap_set_dma_transfer_params(dma_ch, OMAP_DMA_DATA_TYPE_S32,
+			DMA_FRAME_SIZE, block_size >> (DMA_FRAME_SHIFT +
+			DMA_ELEMENT_SHIFT), DMA_SYNC, 0, 0);
+}
+
+#ifdef CONFIG_VIDEO_OMAP1_SG
+static struct scatterlist *try_next_sgbuf(int dma_ch, struct omap1_cam_buf *buf)
+{
+	struct scatterlist *sgbuf;
+
+	if (likely(buf->sgbuf)) {
+
+		if (unlikely(!buf->bytes_left)) {
+			/* indicate sglist complete */
+			sgbuf = NULL;
+		} else {
+			sgbuf = sg_next(buf->sgbuf);
+			if (WARN_ON(!sgbuf)) {
+				buf->result = VIDEOBUF_ERROR;
+			} else if (WARN_ON(!sg_dma_len(sgbuf))) {
+				sgbuf = NULL;
+				buf->result = VIDEOBUF_ERROR;
+			}
+		}
+		buf->sgbuf = sgbuf;
+	} else {
+		struct videobuf_dmabuf *dma = videobuf_to_dma(&buf->vb);
+
+		buf->sgbuf = sgbuf = dma->sglist;
+		if (sgbuf) {
+			buf->sgcount = 0;
+			buf->bytes_left = buf->vb.size;
+			buf->result = VIDEOBUF_DONE;
+		}
+	}
+	if (sgbuf)
+		set_dma_dest_params(dma_ch, buf);
+
+	return sgbuf;
+}
+#endif
+
+static struct omap1_cam_buf *prepare_next_vb(struct omap1_cam_dev *pcdev)
+{
+	struct omap1_cam_buf *buf;
+
+	buf = pcdev->ready;
+	if (!buf) {
+		if (list_empty(&pcdev->capture))
+			return buf;
+		buf = list_entry(pcdev->capture.next,
+				struct omap1_cam_buf, vb.queue);
+		buf->vb.state = VIDEOBUF_ACTIVE;
+		pcdev->ready = buf;
+		list_del_init(&buf->vb.queue);
+	}
+#ifndef CONFIG_VIDEO_OMAP1_SG
+	set_dma_dest_params(pcdev->dma_ch, buf);
+#else
+	buf->sgbuf = NULL;
+#endif
+	return buf;
+}
+
+static void start_capture(struct omap1_cam_dev *pcdev)
+{
+	struct omap1_cam_buf *buf = pcdev->active;
+	unsigned long ctrlclock = CAM_READ_CACHE(pcdev, CTRLCLOCK);
+	unsigned long mode = CAM_READ_CACHE(pcdev, MODE);
+
+	if (WARN_ON(!buf))
+		return;
+
+#ifndef CONFIG_VIDEO_OMAP1_SG
+	/* don't enable end of frame interrupts before capture autostart */
+	mode &= ~EN_V_DOWN;
+#endif
+	if (WARN_ON(mode & RAZ_FIFO))
+		/*  clean up possibly insane reset condition */
+		CAM_WRITE(pcdev, MODE, mode &= ~RAZ_FIFO);
+
+	if (unlikely(ctrlclock & LCLK_EN))
+		/* stop pixel clock before FIFO reset */
+		CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock & ~LCLK_EN);
+	/* reset FIFO */
+	CAM_WRITE(pcdev, MODE, mode | RAZ_FIFO);
+
+	omap_start_dma(pcdev->dma_ch);
+
+	/* (re)enable pixel clock */
+	CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock | LCLK_EN);
+	/* release FIFO reset */
+	CAM_WRITE(pcdev, MODE, mode);
+
+#ifdef CONFIG_VIDEO_OMAP1_SG
+	try_next_sgbuf(pcdev->dma_ch, buf);
+#endif
+}
+
+static void suspend_capture(struct omap1_cam_dev *pcdev)
+{
+	unsigned long ctrlclock = CAM_READ_CACHE(pcdev, CTRLCLOCK);
+
+	CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock & ~LCLK_EN);
+	omap_stop_dma(pcdev->dma_ch);
+}
+
+static void disable_capture(struct omap1_cam_dev *pcdev)
+{
+	unsigned long mode = CAM_READ_CACHE(pcdev, MODE);
+
+	CAM_WRITE(pcdev, MODE, mode & ~(IRQ_MASK | DMA));
+}
+
+static void omap1_videobuf_queue(struct videobuf_queue *vq,
+						struct videobuf_buffer *vb)
+{
+	struct soc_camera_device *icd = vq->priv_data;
+	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
+	struct omap1_cam_dev *pcdev = ici->priv;
+	struct omap1_cam_buf *buf;
+	unsigned long mode;
+
+	list_add_tail(&vb->queue, &pcdev->capture);
+	vb->state = VIDEOBUF_QUEUED;
+
+	if (pcdev->active)
+		return;
+
+	WARN_ON(pcdev->ready);
+
+	buf = prepare_next_vb(pcdev);
+	if (WARN_ON(!buf))
+		return;
+
+	pcdev->active = buf;
+	pcdev->ready = NULL;
+
+	dev_dbg(icd->dev.parent, "%s: capture not active, setup FIFO, start DMA"
+			"\n", __func__);
+	mode = CAM_READ_CACHE(pcdev, MODE) & (THRESHOLD_MASK | ORDERCAMD);
+	mode |= EN_FIFO_FULL | DMA;
+#ifndef CONFIG_VIDEO_OMAP1_SG
+	CAM_WRITE(pcdev, MODE, mode | EN_V_UP);
+#else
+	CAM_WRITE(pcdev, MODE, mode | EN_V_DOWN);
+
+	try_next_sgbuf(pcdev->dma_ch, buf);
+#endif
+	start_capture(pcdev);
+}
+
+static void omap1_videobuf_release(struct videobuf_queue *vq,
+				 struct videobuf_buffer *vb)
+{
+	struct omap1_cam_buf *buf =
+			container_of(vb, struct omap1_cam_buf, vb);
+	struct soc_camera_device *icd = vq->priv_data;
+	struct device *dev = icd->dev.parent;
+
+	switch (vb->state) {
+	case VIDEOBUF_DONE:
+		dev_dbg(dev, "%s (done)\n", __func__);
+		break;
+	case VIDEOBUF_ACTIVE:
+		dev_dbg(dev, "%s (active)\n", __func__);
+		break;
+	case VIDEOBUF_QUEUED:
+		dev_dbg(dev, "%s (queued)\n", __func__);
+		break;
+	case VIDEOBUF_PREPARED:
+		dev_dbg(dev, "%s (prepared)\n", __func__);
+		break;
+	default:
+		dev_dbg(dev, "%s (unknown)\n", __func__);
+		break;
+	}
+
+	free_buffer(vq, buf);
+}
+
+static void videobuf_done(struct omap1_cam_dev *pcdev,
+		enum videobuf_state result)
+{
+	struct omap1_cam_buf *buf = pcdev->active;
+	struct videobuf_buffer *vb;
+	struct device *dev = pcdev->icd->dev.parent;
+
+	if (WARN_ON(!buf)) {
+		suspend_capture(pcdev);
+		disable_capture(pcdev);
+		return;
+	}
+
+	if (result == VIDEOBUF_ERROR)
+		suspend_capture(pcdev);
+
+	vb = &buf->vb;
+	if (waitqueue_active(&vb->done)) {
+		if (!pcdev->ready && result != VIDEOBUF_ERROR)
+			suspend_capture(pcdev);
+		vb->state = result;
+		do_gettimeofday(&vb->ts);
+		vb->field_count++;
+		wake_up(&vb->done);
+
+		pcdev->active = buf = pcdev->ready;
+		pcdev->ready = NULL;
+
+		if (!buf) {
+			result = VIDEOBUF_ERROR;
+			prepare_next_vb(pcdev);
+
+			pcdev->active = buf = pcdev->ready;
+			pcdev->ready = NULL;
+		}
+	} else if (pcdev->ready) {
+		dev_dbg(dev, "%s: nobody waiting on videobuf, swap with next\n",
+				__func__);
+		pcdev->active = pcdev->ready;
+#ifdef CONFIG_VIDEO_OMAP1_SG
+		buf->sgbuf = NULL;
+#endif
+		pcdev->ready = buf;
+
+		buf = pcdev->active;
+	} else {
+#ifndef CONFIG_VIDEO_OMAP1_SG
+		dev_dbg(dev, "%s: nobody waiting on videobuf, reuse it\n",
+				__func__);
+#else
+		if (result != VIDEOBUF_ERROR) {
+			suspend_capture(pcdev);
+			result = VIDEOBUF_ERROR;
+		}
+		prepare_next_vb(pcdev);
+#endif
+	}
+
+	if (!buf) {
+		dev_dbg(dev, "%s: no more videobufs, stop capture\n", __func__);
+		disable_capture(pcdev);
+		return;
+	}
+
+#ifdef CONFIG_VIDEO_OMAP1_SG
+	if (result == VIDEOBUF_ERROR)
+		buf->sgbuf = NULL;
+
+	try_next_sgbuf(pcdev->dma_ch, buf);
+#endif
+
+	if (result == VIDEOBUF_ERROR) {
+		dev_dbg(dev, "%s: videobuf error; reset FIFO, restart DMA\n",
+				__func__);
+		start_capture(pcdev);
+	}
+
+	prepare_next_vb(pcdev);
+}
+
+static void dma_isr(int channel, unsigned short status, void *data)
+{
+	struct omap1_cam_dev *pcdev = data;
+	struct omap1_cam_buf *buf = pcdev->active;
+	enum videobuf_state result;
+	unsigned long flags;
+
+	spin_lock_irqsave(&pcdev->lock, flags);
+
+	if (WARN_ON(!buf)) {
+		suspend_capture(pcdev);
+		disable_capture(pcdev);
+		goto out;
+	}
+
+#ifndef CONFIG_VIDEO_OMAP1_SG
+	/* videobuf complete, disable end of frame interrupt for this frame */
+	CAM_WRITE(pcdev, MODE, CAM_READ_CACHE(pcdev, MODE) & ~EN_V_DOWN);
+	result = VIDEOBUF_DONE;
+#else
+	if (buf->sgbuf) {
+		/* current sglist not complete yet */
+		try_next_sgbuf(pcdev->dma_ch, buf);
+		if (buf->sgbuf)
+			goto out;
+
+		if (buf->result != VIDEOBUF_ERROR) {
+			buf = prepare_next_vb(pcdev);
+			if (!buf)
+				goto out;
+
+			try_next_sgbuf(pcdev->dma_ch, buf);
+			goto out;
+		}
+	}
+	/* end of videobuf */
+	result = buf->result;
+#endif
+	videobuf_done(pcdev, result);
+out:
+	spin_unlock_irqrestore(&pcdev->lock, flags);
+}
+
+static irqreturn_t cam_isr(int irq, void *data)
+{
+	struct omap1_cam_dev *pcdev = data;
+	struct device *dev = pcdev->icd->dev.parent;
+	struct omap1_cam_buf *buf = pcdev->active;
+	unsigned long it_status;
+	unsigned long flags;
+
+	it_status = CAM_READ(pcdev, IT_STATUS);
+	if (!it_status)
+		return IRQ_NONE;
+
+	spin_lock_irqsave(&pcdev->lock, flags);
+
+	if (WARN_ON(!buf)) {
+		suspend_capture(pcdev);
+		disable_capture(pcdev);
+		goto out;
+	}
+
+	if (unlikely(it_status & FIFO_FULL)) {
+		dev_warn(dev, "%s: FIFO overflow\n", __func__);
+
+	} else if (it_status & V_DOWN) {
+#ifdef CONFIG_VIDEO_OMAP1_SG
+		/*
+		 * if exactly 2 sgbufs of the next sglist has be used,
+		 * then we are in sync
+		 */
+		if (buf && buf->sgcount == 2)
+			goto out;
+#endif
+		dev_notice(dev, "%s: unexpected end of video frame\n",
+				__func__);
+
+#ifndef CONFIG_VIDEO_OMAP1_SG
+	} else if (it_status & V_UP) {
+		unsigned long mode = CAM_READ_CACHE(pcdev, MODE);
+
+		if (!(mode & EN_V_DOWN)) {
+			/* enable end of frame interrupt for current videobuf */
+			CAM_WRITE(pcdev, MODE, mode | EN_V_DOWN);
+		}
+		goto out;
+#endif
+
+	} else {
+		dev_warn(pcdev->soc_host.v4l2_dev.dev, "%s: "
+				"unhandled camera interrupt, status == 0x%lx\n",
+				__func__, it_status);
+		goto out;
+	}
+
+	videobuf_done(pcdev, VIDEOBUF_ERROR);
+out:
+	spin_unlock_irqrestore(&pcdev->lock, flags);
+	return IRQ_HANDLED;
+}
+
+static struct videobuf_queue_ops omap1_videobuf_ops = {
+	.buf_setup	= omap1_videobuf_setup,
+	.buf_prepare	= omap1_videobuf_prepare,
+	.buf_queue	= omap1_videobuf_queue,
+	.buf_release	= omap1_videobuf_release,
+};
+
+
+/*
+ * SOC Camera host operations
+ */
+
+static void sensor_reset(struct omap1_cam_dev *pcdev, bool reset)
+{
+	/* apply/release camera sensor reset if requested by platform data */
+	if (pcdev->pflags & OMAP1_CAMERA_RST_HIGH)
+		CAM_WRITE(pcdev, GPIO, reset);
+	else if (pcdev->pflags & OMAP1_CAMERA_RST_LOW)
+		CAM_WRITE(pcdev, GPIO, !reset);
+}
+
+/*
+ * The following two functions absolutely depend on the fact, that
+ * there can be only one camera on OMAP1 camera sensor interface
+ */
+static int omap1_cam_add_device(struct soc_camera_device *icd)
+{
+	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
+	struct omap1_cam_dev *pcdev = ici->priv;
+	unsigned int ctrlclock;
+	int ret = 0;
+
+	if (pcdev->icd) {
+		ret = -EBUSY;
+		goto ebusy;
+	}
+
+	clk_enable(pcdev->clk);
+
+	/* setup sensor clock */
+	ctrlclock = CAM_READ(pcdev, CTRLCLOCK);
+	ctrlclock &= ~(CAMEXCLK_EN | MCLK_EN | DPLL_EN);
+	CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock);
+
+	ctrlclock &= ~FOSCMOD_MASK;
+	switch (pcdev->camexclk) {
+	case CAM_EXCLK_6MHz:
+		ctrlclock |= CAMEXCLK_EN | FOSCMOD_6MHz;
+		break;
+	case CAM_EXCLK_8MHz:
+		ctrlclock |= CAMEXCLK_EN | FOSCMOD_8MHz | DPLL_EN;
+		break;
+	case CAM_EXCLK_9_6MHz:
+		ctrlclock |= CAMEXCLK_EN | FOSCMOD_9_6MHz | DPLL_EN;
+		break;
+	case CAM_EXCLK_12MHz:
+		ctrlclock |= CAMEXCLK_EN | FOSCMOD_12MHz;
+		break;
+	case CAM_EXCLK_24MHz:
+		ctrlclock |= CAMEXCLK_EN | FOSCMOD_24MHz | DPLL_EN;
+	default:
+		break;
+	}
+	CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock & ~DPLL_EN);
+
+	/* enable clock */
+	ctrlclock |= MCLK_EN;
+	CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock);
+
+	sensor_reset(pcdev, 0);
+
+	pcdev->icd = icd;
+
+	dev_info(icd->dev.parent, "OMAP1 Camera driver attached to camera %d\n",
+		 icd->devnum);
+ebusy:
+	return ret;
+}
+
+static void omap1_cam_remove_device(struct soc_camera_device *icd)
+{
+	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
+	struct omap1_cam_dev *pcdev = ici->priv;
+	unsigned long ctrlclock;
+
+	BUG_ON(icd != pcdev->icd);
+
+	suspend_capture(pcdev);
+	disable_capture(pcdev);
+
+	sensor_reset(pcdev, 1);
+
+	/* disable and release system clocks */
+	ctrlclock = CAM_READ(pcdev, CTRLCLOCK);
+	ctrlclock &= ~(MCLK_EN | DPLL_EN | CAMEXCLK_EN);
+	CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock);
+
+	ctrlclock = (ctrlclock & ~FOSCMOD_MASK) | FOSCMOD_12MHz;
+	CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock);
+	CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock | MCLK_EN);
+
+	CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock & ~MCLK_EN);
+
+	clk_disable(pcdev->clk);
+
+	pcdev->icd = NULL;
+
+	dev_info(icd->dev.parent, "OMAP1 Camera driver detached from camera %d"
+			"\n", icd->devnum);
+}
+
+/* Duplicate standard formats based on host capability of byte swapping */
+static const struct soc_mbus_pixelfmt omap1_cam_formats[] = {
+	[V4L2_MBUS_FMT_YUYV8_2X8_BE] = {
+		.fourcc			= V4L2_PIX_FMT_YUYV,
+		.name			= "YUYV",
+		.bits_per_sample	= 8,
+		.packing		= SOC_MBUS_PACKING_2X8_PADHI,
+		.order			= SOC_MBUS_ORDER_BE,
+	},
+	[V4L2_MBUS_FMT_YVYU8_2X8_BE] = {
+		.fourcc			= V4L2_PIX_FMT_YVYU,
+		.name			= "YVYU",
+		.bits_per_sample	= 8,
+		.packing		= SOC_MBUS_PACKING_2X8_PADHI,
+		.order			= SOC_MBUS_ORDER_BE,
+	},
+	[V4L2_MBUS_FMT_YUYV8_2X8_LE] = {
+		.fourcc			= V4L2_PIX_FMT_UYVY,
+		.name			= "UYVY",
+		.bits_per_sample	= 8,
+		.packing		= SOC_MBUS_PACKING_2X8_PADHI,
+		.order			= SOC_MBUS_ORDER_BE,
+	},
+	[V4L2_MBUS_FMT_YVYU8_2X8_LE] = {
+		.fourcc			= V4L2_PIX_FMT_VYUY,
+		.name			= "VYUY",
+		.bits_per_sample	= 8,
+		.packing		= SOC_MBUS_PACKING_2X8_PADHI,
+		.order			= SOC_MBUS_ORDER_BE,
+	},
+	[V4L2_MBUS_FMT_RGB555_2X8_PADHI_BE] = {
+		.fourcc			= V4L2_PIX_FMT_RGB555,
+		.name			= "RGB555",
+		.bits_per_sample	= 8,
+		.packing		= SOC_MBUS_PACKING_2X8_PADHI,
+		.order			= SOC_MBUS_ORDER_BE,
+	},
+	[V4L2_MBUS_FMT_RGB555_2X8_PADHI_LE] = {
+		.fourcc			= V4L2_PIX_FMT_RGB555X,
+		.name			= "RGB555X",
+		.bits_per_sample	= 8,
+		.packing		= SOC_MBUS_PACKING_2X8_PADHI,
+		.order			= SOC_MBUS_ORDER_BE,
+	},
+	[V4L2_MBUS_FMT_RGB565_2X8_BE] = {
+		.fourcc			= V4L2_PIX_FMT_RGB565,
+		.name			= "RGB565",
+		.bits_per_sample	= 8,
+		.packing		= SOC_MBUS_PACKING_2X8_PADHI,
+		.order			= SOC_MBUS_ORDER_BE,
+	},
+	[V4L2_MBUS_FMT_RGB565_2X8_LE] = {
+		.fourcc			= V4L2_PIX_FMT_RGB565X,
+		.name			= "RGB565X",
+		.bits_per_sample	= 8,
+		.packing		= SOC_MBUS_PACKING_2X8_PADHI,
+		.order			= SOC_MBUS_ORDER_BE,
+	},
+};
+
+static int omap1_cam_get_formats(struct soc_camera_device *icd,
+		unsigned int idx, struct soc_camera_format_xlate *xlate)
+{
+	struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
+	struct device *dev = icd->dev.parent;
+	int formats = 0, ret;
+	enum v4l2_mbus_pixelcode code;
+	const struct soc_mbus_pixelfmt *fmt;
+
+	ret = v4l2_subdev_call(sd, video, enum_mbus_fmt, idx, &code);
+	if (ret < 0)
+		/* No more formats */
+		return 0;
+
+	fmt = soc_mbus_get_fmtdesc(code);
+	if (!fmt) {
+		dev_err(dev, "%s: invalid format code #%d: %d\n", __func__,
+				idx, code);
+		return 0;
+	}
+
+	/* Check support for the requested bits-per-sample */
+	if (fmt->bits_per_sample != 8)
+		return 0;
+
+	switch (code) {
+	case V4L2_MBUS_FMT_YUYV8_2X8_BE:
+	case V4L2_MBUS_FMT_YVYU8_2X8_BE:
+	case V4L2_MBUS_FMT_YUYV8_2X8_LE:
+	case V4L2_MBUS_FMT_YVYU8_2X8_LE:
+	case V4L2_MBUS_FMT_RGB555_2X8_PADHI_BE:
+	case V4L2_MBUS_FMT_RGB555_2X8_PADHI_LE:
+	case V4L2_MBUS_FMT_RGB565_2X8_BE:
+	case V4L2_MBUS_FMT_RGB565_2X8_LE:
+		formats++;
+		if (xlate) {
+			xlate->host_fmt	= &omap1_cam_formats[code];
+			xlate->code	= code;
+			xlate++;
+			dev_dbg(dev, "%s: providing format %s "
+					"as byte swapped code #%d\n", __func__,
+					omap1_cam_formats[code].name, code);
+		}
+	default:
+		if (xlate)
+			dev_dbg(dev, "%s: providing format %s "
+					"in pass-through mode\n", __func__,
+					fmt->name);
+	}
+	formats++;
+	if (xlate) {
+		xlate->host_fmt	= fmt;
+		xlate->code	= code;
+		xlate++;
+	}
+
+	return formats;
+}
+
+static int is_dma_aligned(s32 bytes_per_line, unsigned int height)
+{
+	int size = bytes_per_line * height;
+
+	return IS_ALIGNED(bytes_per_line, DMA_ELEMENT_SIZE) &&
+			IS_ALIGNED(size, DMA_FRAME_SIZE * DMA_ELEMENT_SIZE);
+}
+
+static int dma_align(int *width, int *height,
+		const struct soc_mbus_pixelfmt *fmt, bool enlarge)
+{
+	s32 bytes_per_line = soc_mbus_bytes_per_line(*width, fmt);
+
+	if (bytes_per_line < 0)
+		return bytes_per_line;
+
+	if (!is_dma_aligned(bytes_per_line, *height)) {
+		unsigned int pxalign = __fls(bytes_per_line / *width);
+		unsigned int salign  =
+				DMA_FRAME_SHIFT + DMA_ELEMENT_SHIFT - pxalign;
+		unsigned int incr    = enlarge << salign;
+
+		v4l_bound_align_image(width, DMA_ELEMENT_SIZE >> pxalign,
+				*width + incr, DMA_ELEMENT_SHIFT - pxalign,
+				height, 1, *height + incr, 0, salign);
+		return 0;
+	}
+	return 1;
+}
+
+/* returns 1 on g_crop() success, 0 on cropcap() success, <0 on error */
+static int get_crop(struct soc_camera_device *icd, struct v4l2_rect *rect)
+{
+	struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
+	struct device *dev = icd->dev.parent;
+	struct v4l2_crop crop;
+	int ret;
+
+	crop.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+	ret = v4l2_subdev_call(sd, video, g_crop, &crop);
+	if (ret == -ENOIOCTLCMD) {
+		struct v4l2_cropcap cc;
+
+		dev_dbg(dev, "%s: g_crop() missing, trying cropcap() instead"
+				"\n", __func__);
+		cc.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+		ret = v4l2_subdev_call(sd, video, cropcap, &cc);
+		if (ret < 0)
+			return ret;
+		*rect = cc.defrect;
+		return 0;
+	} else if (ret < 0) {
+		return ret;
+	}
+	*rect  = crop.c;
+	return 1;
+}
+
+/*
+ * returns 1 on g_mbus_fmt() or g_crop() success, 0 on cropcap() success,
+ * <0 on error
+ */
+static int get_geometry(struct soc_camera_device *icd, struct v4l2_rect *rect,
+		enum v4l2_mbus_pixelcode code)
+{
+	struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
+	struct device *dev = icd->dev.parent;
+	struct v4l2_mbus_framefmt mf;
+	int ret;
+
+	ret = v4l2_subdev_call(sd, video, g_mbus_fmt, &mf);
+	if (ret == -ENOIOCTLCMD) {
+		struct v4l2_rect c;
+
+		dev_dbg(dev, "%s: g_mbus_fmt() missing, trying g_crop() instead"
+				"\n", __func__);
+		ret = get_crop(icd, &c);
+		if (ret < 0)
+			return ret;
+		/* REVISIT:
+		 * Should cropcap() obtained defrect reflect last s_crop()?
+		 * Can we use it here for s_crop() result verification?
+		 */
+		if (ret) {
+			*rect = c;	/* use g_crop() result */
+		} else {
+			dev_warn(dev, "%s: current geometry not available\n",
+					__func__);
+			return 0;
+		}
+	} else if (ret < 0) {
+		return ret;
+	} else if (mf.code != code) {
+		return -EINVAL;
+	} else {
+		rect->width  = mf.width;
+		rect->height = mf.height;
+	}
+	return 1;
+}
+
+#define subdev_call_with_sense(ret, function, args...) \
+{ \
+	struct soc_camera_sense sense = { \
+		.master_clock		= pcdev->camexclk, \
+		.pixel_clock_max	= 0, \
+	}; \
+\
+	if (pcdev->pdata) \
+		sense.pixel_clock_max = pcdev->pdata->lclk_khz_max * 1000; \
+	icd->sense = &sense; \
+	*(ret) = v4l2_subdev_call(sd, video, function, ##args); \
+	icd->sense = NULL; \
+\
+	if (sense.flags & SOCAM_SENSE_PCLK_CHANGED) { \
+		if (sense.pixel_clock > sense.pixel_clock_max) { \
+			dev_err(dev, "%s: " \
+				"pixel clock %lu set by the camera too high!" \
+				"\n", __func__, sense.pixel_clock); \
+			return -EIO; \
+		} \
+	} \
+}
+
+static int omap1_cam_set_crop(struct soc_camera_device *icd,
+			       struct v4l2_crop *crop)
+{
+	struct v4l2_rect *rect = &crop->c;
+	struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
+	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
+	struct omap1_cam_dev *pcdev = ici->priv;
+	struct device *dev = icd->dev.parent;
+	s32 bytes_per_line;
+	int ret;
+
+	ret = dma_align(&rect->width, &rect->height, icd->current_fmt->host_fmt,
+			false);
+	if (ret < 0) {
+		dev_err(dev, "%s: failed to align %ux%u %s with DMA\n",
+				__func__, rect->width, rect->height,
+				icd->current_fmt->host_fmt->name);
+		return ret;
+	}
+
+	subdev_call_with_sense(&ret, s_crop, crop);
+	if (ret < 0) {
+		dev_warn(dev, "%s: failed to crop to %ux%u@%u:%u\n", __func__,
+			 rect->width, rect->height, rect->left, rect->top);
+		return ret;
+	}
+
+	ret = get_geometry(icd, rect, icd->current_fmt->code);
+	if (ret < 0) {
+		dev_err(dev, "%s: get_geometry() failed\n", __func__);
+		return ret;
+	}
+	if (!ret) {
+		dev_warn(dev, "%s: unable to verify s_crop() results\n",
+				__func__);
+	}
+
+	bytes_per_line = soc_mbus_bytes_per_line(rect->width,
+			icd->current_fmt->host_fmt);
+	if (bytes_per_line < 0) {
+		dev_err(dev, "%s: soc_mbus_bytes_per_line() failed\n",
+				__func__);
+		return bytes_per_line;
+	}
+
+	ret = is_dma_aligned(bytes_per_line, rect->height);
+	if (ret < 0) {
+		dev_err(dev, "%s: is_dma_aligned() failed\n", __func__);
+		return ret;
+	}
+	if (!ret) {
+		dev_err(dev, "%s: resulting geometry %dx%d not DMA aligned\n",
+				__func__, rect->width, rect->height);
+		return -EINVAL;
+	}
+
+	icd->user_width	 = rect->width;
+	icd->user_height = rect->height;
+
+	return ret;
+}
+
+static int omap1_cam_set_fmt(struct soc_camera_device *icd,
+			      struct v4l2_format *f)
+{
+	struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
+	const struct soc_camera_format_xlate *xlate;
+	struct device *dev = icd->dev.parent;
+	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
+	struct omap1_cam_dev *pcdev = ici->priv;
+	struct v4l2_pix_format *pix = &f->fmt.pix;
+	struct v4l2_mbus_framefmt mf;
+	struct v4l2_crop crop;
+	struct v4l2_rect *rect = &crop.c;
+	int bytes_per_line;
+	int ret;
+
+	xlate = soc_camera_xlate_by_fourcc(icd, pix->pixelformat);
+	if (!xlate) {
+		dev_warn(dev, "%s: format %x not found\n", __func__,
+				pix->pixelformat);
+		return -EINVAL;
+	}
+
+	bytes_per_line = soc_mbus_bytes_per_line(pix->width, xlate->host_fmt);
+	if (bytes_per_line < 0) {
+		dev_err(dev, "%s: soc_mbus_bytes_per_line() failed\n",
+				__func__);
+		return bytes_per_line;
+	}
+	if (pix->bytesperline && pix->bytesperline != bytes_per_line) {
+		dev_err(dev, "%s: bytes per line mismatch\n", __func__);
+		return -EINVAL;
+	}
+	ret = is_dma_aligned(bytes_per_line, pix->height);
+	if (ret < 0) {
+		dev_err(dev, "%s: is_dma_aligned() failed\n", __func__);
+		return ret;
+	}
+	if (!ret) {
+		dev_err(dev, "%s: image size %dx%d not DMA aligned\n",
+				__func__, pix->width, pix->height);
+		return -EINVAL;
+	}
+
+	mf.width	= pix->width;
+	mf.height	= pix->height;
+	mf.field	= pix->field;
+	mf.colorspace	= pix->colorspace;
+	mf.code		= xlate->code;
+
+	subdev_call_with_sense(&ret, s_mbus_fmt, &mf);
+	if (ret < 0) {
+		dev_err(dev, "%s: failed to set format\n", __func__);
+		return ret;
+	}
+
+	if (mf.code != xlate->code) {
+		dev_err(dev, "%s: unexpected pixel code change\n", __func__);
+		return -EINVAL;
+	}
+	icd->current_fmt = xlate;
+
+	pix->field	= mf.field;
+	pix->colorspace	= mf.colorspace;
+
+	if (mf.width == pix->width && mf.height == pix->height)
+		return 0;
+
+	dev_notice(dev, "%s: sensor geometry differs, trying to crop to %dx%d"
+			"\n", __func__, pix->width, pix->height);
+	crop.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+	ret = get_crop(icd, rect);
+	if (ret < 0) {
+		dev_err(dev, "%s: get_crop() failed\n", __func__);
+		return ret;
+	}
+
+	rect->width  = pix->width;
+	rect->height = pix->height;
+
+	subdev_call_with_sense(&ret, s_crop, &crop);
+	if (ret < 0) {
+		dev_warn(dev, "%s: failed to crop to %ux%u@%u:%u\n", __func__,
+			 rect->width, rect->height, rect->left, rect->top);
+		return ret;
+	}
+
+	ret = get_geometry(icd, rect, xlate->code);
+	if (ret < 0) {
+		dev_err(dev, "%s: get_geometry() failed\n", __func__);
+		return ret;
+	}
+
+	if (!ret) {
+		dev_warn(dev, "%s: s_crop() results not verified\n", __func__);
+		return 0;
+	}
+
+	if (pix->width != rect->width || pix->height != rect->height) {
+		dev_err(dev, "%s: tried to set %dx%d, got %dx%d\n", __func__,
+				pix->width, pix->height,
+				rect->width, rect->height);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int omap1_cam_try_fmt(struct soc_camera_device *icd,
+			      struct v4l2_format *f)
+{
+	struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
+	const struct soc_camera_format_xlate *xlate;
+	struct device *dev = icd->dev.parent;
+	struct v4l2_pix_format *pix = &f->fmt.pix;
+	struct v4l2_mbus_framefmt mf, testmf;
+	const struct soc_mbus_pixelfmt *fmt;
+	int ret;
+
+	xlate = soc_camera_xlate_by_fourcc(icd, pix->pixelformat);
+	if (!xlate) {
+		dev_warn(dev, "%s: format %x not found\n", __func__,
+				pix->pixelformat);
+		return -EINVAL;
+	}
+
+	fmt = xlate->host_fmt;
+	ret = dma_align(&pix->width, &pix->height, fmt, true);
+	if (ret < 0) {
+		dev_err(dev, "%s: failed to align %ux%u %s with DMA\n",
+				__func__, pix->width, pix->height, fmt->name);
+		return ret;
+	}
+
+	mf.width      = pix->width;
+	mf.height     = pix->height;
+	mf.field      = pix->field;
+	mf.colorspace = pix->colorspace;
+	mf.code	      = xlate->code;
+
+	/* limit to sensor capabilities */
+	ret = v4l2_subdev_call(sd, video, try_mbus_fmt, &mf);
+	if (ret < 0) {
+		dev_err(dev, "%s: try_mbus_fmt() failed\n", __func__);
+		return ret;
+	}
+
+	pix->field	= mf.field;
+	pix->colorspace	= mf.colorspace;
+
+	if (mf.width == pix->width && mf.height == pix->height &&
+			mf.code == xlate->code)
+		return 0;
+
+	dev_dbg(dev, "%s: geometry changed, recheck alignment\n", __func__);
+	pix->width	  = mf.width;
+	pix->height	  = mf.height;
+
+	fmt = soc_mbus_get_fmtdesc(mf.code);
+	ret = dma_align(&pix->width, &pix->height, fmt, false);
+	if (ret < 0) {
+		dev_err(dev, "%s: failed to align %ux%u %s with DMA\n",
+				__func__, pix->width, pix->height, fmt->name);
+		return ret;
+	}
+	if (ret)
+		return 0;
+
+	testmf.width	  = pix->width;
+	testmf.height	  = pix->height;
+	testmf.field	  = mf.field;
+	testmf.colorspace = mf.colorspace;
+	testmf.code	  = mf.code;
+
+	ret = v4l2_subdev_call(sd, video, try_mbus_fmt, &testmf);
+	if (ret < 0) {
+		dev_err(dev, "%s: try_mbus_fmt() failed\n", __func__);
+		return ret;
+	}
+
+	if (testmf.code != mf.code || testmf.width != mf.width ||
+			testmf.height != mf.height) {
+		dev_err(dev, "%s: sensor format inconsistency, giving up\n",
+				__func__);
+		return -EINVAL;
+	}
+	dev_notice(dev, "%s: "
+		"sensor frame not DMA aligned, will try to crop from set_fmt()"
+		"\n", __func__);
+
+	return 0;
+}
+
+static void omap1_cam_init_videobuf(struct videobuf_queue *q,
+				     struct soc_camera_device *icd)
+{
+	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
+	struct omap1_cam_dev *pcdev = ici->priv;
+
+#ifndef CONFIG_VIDEO_OMAP1_SG
+	videobuf_queue_dma_contig_init(q, &omap1_videobuf_ops, icd->dev.parent,
+					&pcdev->lock,
+					V4L2_BUF_TYPE_VIDEO_CAPTURE,
+					V4L2_FIELD_NONE,
+					sizeof(struct omap1_cam_buf),
+					icd);
+#else
+	videobuf_queue_sg_init(q, &omap1_videobuf_ops, icd->dev.parent,
+					&pcdev->lock,
+					V4L2_BUF_TYPE_VIDEO_CAPTURE,
+					V4L2_FIELD_NONE,
+					sizeof(struct omap1_cam_buf),
+					icd);
+#endif
+}
+
+static int omap1_cam_reqbufs(struct soc_camera_file *icf,
+			      struct v4l2_requestbuffers *p)
+{
+	int i;
+
+	/*
+	 * This is for locking debugging only. I removed spinlocks and now I
+	 * check whether .prepare is ever called on a linked buffer, or whether
+	 * a dma IRQ can occur for an in-work or unlinked buffer. Until now
+	 * it hadn't triggered
+	 */
+	for (i = 0; i < p->count; i++) {
+		struct omap1_cam_buf *buf = container_of(icf->vb_vidq.bufs[i],
+						      struct omap1_cam_buf, vb);
+		buf->inwork = 0;
+		INIT_LIST_HEAD(&buf->vb.queue);
+	}
+
+	return 0;
+}
+
+static int omap1_cam_querycap(struct soc_camera_host *ici,
+			       struct v4l2_capability *cap)
+{
+	/* cap->name is set by the friendly caller:-> */
+	strlcpy(cap->card, "OMAP1 Camera", sizeof(cap->card));
+	cap->version = VERSION_CODE;
+	cap->capabilities = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
+
+	return 0;
+}
+
+static int omap1_cam_set_bus_param(struct soc_camera_device *icd,
+		__u32 pixfmt)
+{
+	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
+	struct omap1_cam_dev *pcdev = ici->priv;
+	struct device *dev = icd->dev.parent;
+	const struct soc_camera_format_xlate *xlate;
+	const struct soc_mbus_pixelfmt *fmt;
+	unsigned long camera_flags, common_flags;
+	unsigned int ctrlclock, mode;
+	int ret;
+
+	camera_flags = icd->ops->query_bus_param(icd);
+
+	common_flags = soc_camera_bus_param_compatible(camera_flags,
+			SOCAM_BUS_FLAGS);
+	if (!common_flags)
+		return -EINVAL;
+
+	/* Make choices, possibly based on platform configuration */
+	if ((common_flags & SOCAM_PCLK_SAMPLE_RISING) &&
+			(common_flags & SOCAM_PCLK_SAMPLE_FALLING)) {
+		if (!pcdev->pdata ||
+				pcdev->pdata->flags & OMAP1_CAMERA_LCLK_RISING)
+			common_flags &= ~SOCAM_PCLK_SAMPLE_FALLING;
+		else
+			common_flags &= ~SOCAM_PCLK_SAMPLE_RISING;
+	}
+
+	ret = icd->ops->set_bus_param(icd, common_flags);
+	if (ret < 0)
+		return ret;
+
+	ctrlclock = CAM_READ_CACHE(pcdev, CTRLCLOCK);
+	if (ctrlclock & LCLK_EN)
+		CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock & ~LCLK_EN);
+
+	if (common_flags & SOCAM_PCLK_SAMPLE_RISING) {
+		dev_dbg(dev, "CTRLCLOCK_REG |= POLCLK\n");
+		ctrlclock |= POLCLK;
+	} else {
+		dev_dbg(dev, "CTRLCLOCK_REG &= ~POLCLK\n");
+		ctrlclock &= ~POLCLK;
+	}
+	CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock & ~LCLK_EN);
+
+	if (ctrlclock & LCLK_EN)
+		CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock);
+
+	/* select bus endianess */
+	xlate = soc_camera_xlate_by_fourcc(icd, pixfmt);
+	fmt = xlate->host_fmt;
+
+	if (fmt->order == SOC_MBUS_ORDER_LE) {
+		dev_dbg(dev, "MODE_REG &= ~ORDERCAMD\n");
+		mode = CAM_READ(pcdev, MODE) & ~ORDERCAMD;
+	} else {
+		dev_dbg(dev, "MODE_REG |= ORDERCAMD\n");
+		mode = CAM_READ(pcdev, MODE) | ORDERCAMD;
+	}
+	CAM_WRITE(pcdev, MODE, mode);
+
+	return 0;
+}
+
+static unsigned int omap1_cam_poll(struct file *file, poll_table *pt)
+{
+	struct soc_camera_file *icf = file->private_data;
+	struct omap1_cam_buf *buf;
+
+	buf = list_entry(icf->vb_vidq.stream.next, struct omap1_cam_buf,
+			 vb.stream);
+
+	poll_wait(file, &buf->vb.done, pt);
+
+	if (buf->vb.state == VIDEOBUF_DONE ||
+	    buf->vb.state == VIDEOBUF_ERROR)
+		return POLLIN | POLLRDNORM;
+
+	return 0;
+}
+
+static struct soc_camera_host_ops omap1_host_ops = {
+	.owner		= THIS_MODULE,
+	.add		= omap1_cam_add_device,
+	.remove		= omap1_cam_remove_device,
+	.get_formats	= omap1_cam_get_formats,
+	.set_crop	= omap1_cam_set_crop,
+	.set_fmt	= omap1_cam_set_fmt,
+	.try_fmt	= omap1_cam_try_fmt,
+	.init_videobuf	= omap1_cam_init_videobuf,
+	.reqbufs	= omap1_cam_reqbufs,
+	.querycap	= omap1_cam_querycap,
+	.set_bus_param	= omap1_cam_set_bus_param,
+	.poll		= omap1_cam_poll,
+};
+
+static int __init omap1_cam_probe(struct platform_device *pdev)
+{
+	struct omap1_cam_dev *pcdev;
+	struct resource *res;
+	struct clk *clk;
+	void __iomem *base;
+	unsigned int irq;
+	int err = 0;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	irq = platform_get_irq(pdev, 0);
+	if (!res || (int)irq <= 0) {
+		err = -ENODEV;
+		goto exit;
+	}
+
+	clk = clk_get(&pdev->dev, "armper_ck");
+	if (IS_ERR(clk)) {
+		err = PTR_ERR(clk);
+		goto exit;
+	}
+
+	pcdev = kzalloc(sizeof(*pcdev), GFP_KERNEL);
+	if (!pcdev) {
+		dev_err(&pdev->dev, "Could not allocate pcdev\n");
+		err = -ENOMEM;
+		goto exit_put_clk;
+	}
+
+	pcdev->res = res;
+	pcdev->clk = clk;
+
+	pcdev->pdata = pdev->dev.platform_data;
+	pcdev->pflags = pcdev->pdata->flags;
+
+	if (pcdev->pdata)
+		pcdev->camexclk = pcdev->pdata->camexclk_khz * 1000;
+
+	switch (pcdev->camexclk) {
+	case CAM_EXCLK_6MHz:
+	case CAM_EXCLK_8MHz:
+	case CAM_EXCLK_9_6MHz:
+	case CAM_EXCLK_12MHz:
+	case CAM_EXCLK_24MHz:
+		break;
+	default:
+		dev_warn(&pdev->dev,
+				"Incorrect sensor clock frequency %ld kHz, "
+				"should be one of 0, 6, 8, 9.6, 12 or 24 MHz, "
+				"please correct your platform data\n",
+				pcdev->pdata->camexclk_khz);
+		pcdev->camexclk = 0;
+	case 0:
+		dev_info(&pdev->dev,
+				"Not providing sensor clock\n");
+	}
+
+	INIT_LIST_HEAD(&pcdev->capture);
+	spin_lock_init(&pcdev->lock);
+
+	/*
+	 * Request the region.
+	 */
+	if (!request_mem_region(res->start, resource_size(res), DRIVER_NAME)) {
+		err = -EBUSY;
+		goto exit_kfree;
+	}
+
+	base = ioremap(res->start, resource_size(res));
+	if (!base) {
+		err = -ENOMEM;
+		goto exit_release;
+	}
+	pcdev->irq = irq;
+	pcdev->base = base;
+
+	/* apply reset to camera sensor if requested by platform data */
+	if (pcdev->pflags & OMAP1_CAMERA_RST_HIGH)
+		CAM_WRITE(pcdev, GPIO, 0x1);
+	else if (pcdev->pflags & OMAP1_CAMERA_RST_LOW)
+		CAM_WRITE(pcdev, GPIO, 0x0);
+
+	err = omap_request_dma(OMAP_DMA_CAMERA_IF_RX, DRIVER_NAME,
+			dma_isr, (void *)pcdev, &pcdev->dma_ch);
+	if (err < 0) {
+		dev_err(&pdev->dev, "Can't request DMA for OMAP1 Camera\n");
+		err = -EBUSY;
+		goto exit_iounmap;
+	}
+	dev_dbg(&pdev->dev, "got DMA channel %d\n", pcdev->dma_ch);
+
+	/* preconfigure DMA */
+	omap_set_dma_src_params(pcdev->dma_ch, OMAP_DMA_PORT_TIPB,
+			OMAP_DMA_AMODE_CONSTANT, res->start + REG_CAMDATA,
+			0, 0);
+	omap_set_dma_dest_burst_mode(pcdev->dma_ch, OMAP_DMA_DATA_BURST_4);
+	/* setup DMA autoinitialization */
+	omap_dma_link_lch(pcdev->dma_ch, pcdev->dma_ch);
+
+	CAM_WRITE(pcdev, MODE, THRESHOLD_LEVEL << THRESHOLD_SHIFT);
+
+	err = request_irq(pcdev->irq, cam_isr, 0, DRIVER_NAME, pcdev);
+	if (err) {
+		dev_err(&pdev->dev, "Camera interrupt register failed\n");
+		goto exit_free_dma;
+	}
+
+	pcdev->soc_host.drv_name	= DRIVER_NAME;
+	pcdev->soc_host.ops		= &omap1_host_ops;
+	pcdev->soc_host.priv		= pcdev;
+	pcdev->soc_host.v4l2_dev.dev	= &pdev->dev;
+	pcdev->soc_host.nr		= pdev->id;
+
+	err = soc_camera_host_register(&pcdev->soc_host);
+	if (err)
+		goto exit_free_irq;
+
+	dev_info(&pdev->dev, "OMAP1 Camera Interface driver loaded\n");
+
+	return 0;
+
+exit_free_irq:
+	free_irq(pcdev->irq, pcdev);
+exit_free_dma:
+	omap_free_dma(pcdev->dma_ch);
+exit_iounmap:
+	iounmap(base);
+exit_release:
+	release_mem_region(res->start, resource_size(res));
+exit_kfree:
+	kfree(pcdev);
+exit_put_clk:
+	clk_put(clk);
+exit:
+	return err;
+}
+
+static int __exit omap1_cam_remove(struct platform_device *pdev)
+{
+	struct soc_camera_host *soc_host = to_soc_camera_host(&pdev->dev);
+	struct omap1_cam_dev *pcdev = container_of(soc_host,
+					struct omap1_cam_dev, soc_host);
+	struct resource *res;
+
+	soc_camera_host_unregister(soc_host);
+
+	free_irq(pcdev->irq, pcdev);
+
+	omap_free_dma(pcdev->dma_ch);
+
+	iounmap(pcdev->base);
+
+	res = pcdev->res;
+	release_mem_region(res->start, resource_size(res));
+
+	kfree(pcdev);
+
+	clk_put(pcdev->clk);
+
+	dev_info(&pdev->dev, "OMAP1 Camera Interface driver unloaded\n");
+
+	return 0;
+}
+
+static struct platform_driver omap1_cam_driver = {
+	.driver		= {
+		.name	= DRIVER_NAME,
+	},
+	.probe		= omap1_cam_probe,
+	.remove		= __exit_p(omap1_cam_remove),
+};
+
+static int __init omap1_cam_init(void)
+{
+	return platform_driver_register(&omap1_cam_driver);
+}
+
+static void __exit omap1_cam_exit(void)
+{
+	platform_driver_unregister(&omap1_cam_driver);
+}
+
+module_init(omap1_cam_init);
+module_exit(omap1_cam_exit);
+
+MODULE_DESCRIPTION("OMAP1 Camera Interface driver");
+MODULE_AUTHOR("Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRIVER_NAME);

Re: [RFC] [PATCH 1/6] SoC Camera: add driver for OMAP1 camera interface

[Guennadi Liakhovetski]

Hi Janusz

Thanks once more for the patches, from your patches it is obvious, that 
you've spent quite a bit of time on them and you have not just copy-pasted 
various bits and pieces from other drivers, just filling your hardware 
details, but you also actually understand a lot of what is actually going 
on in there. So, I think, fixing remaining mostly minor issues shouldn't 
be too difficult for you either.

On Sun, 18 Jul 2010, Janusz Krzysztofik wrote:

> This is a V4L2 driver for TI OMAP1 SoC camera interface.
> 
> Two versions of the driver are provided, using either videobuf-dma-contig or 
> videobuf-dma-sg. The former uses less processing power, but often fails to 
> allocate contignuous buffer memory. The latter is free of this problem, but 
> generates tens of DMA interrupts per frame.

Hm, would it be difficult to first try contig, and if it fails - fall back 
to sg?

In its present state buffer management in your driver is pretty difficult 
to follow. At the VERY least you have to extensively document your buffer 
manipulations. Better yet clean it up. AFAIU, your "ready" pointer is 
pretty much unused in the contiguous case. Or you can easily get rid of 
it. So, I think, a very welcome improvement to the driver would be a 
cleaner separation between the two cases. Don't try that much to reuse the 
code as much as possible. Would be much better to have clean separation 
between the two implementations - whether dynamically switchable at 
runtime or at config time - would be best to separate the two 
implementations to the point, where each of them becomes understandable 
and maintainable.

So, I will do a pretty formal review this time and wait for v2. And in v2 
I'd like to at the very least see detailed buffer-management 
documentation, or - better yet - a rework with a clean separation.

> Both versions work stable for me, 
> even under heavy load, on my OMAP1510 based Amstrad Delta videophone, that is 
> the oldest, least powerfull OMAP1 implementation.
> 
> The interface generally works in pass-through mode. Since input data byte 
> endianess can be swapped, it provides up to two v4l2 pixel formats per each of 
> several soc_mbus formats that have their swapped endian counterparts.
> 
> Boards using this driver can provide it with the followning information:
> - if and what freqency clock is expected by an on-board camera sensor,
> - what is the maximum pixel clock that should be accepted from the sensor,
> - what is the polarity of the sensor provided pixel clock,
> - if the interface GPIO line is connected to a sensor reset/powerdown input 
>   and what is the input polarity.
> 
> Created and tested against linux-2.6.35-rc3 on Amstrad Delta.
> 
> Signed-off-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
> ---
>  drivers/media/video/Kconfig        |   14
>  drivers/media/video/Makefile       |    1
>  drivers/media/video/omap1_camera.c | 1656 +++++++++++++++++++++++++++++++++++++
>  include/media/omap1_camera.h       |   16
>  4 files changed, 1687 insertions(+)
> 
> --- linux-2.6.35-rc3.orig/include/media/omap1_camera.h	1970-01-01 01:00:00.000000000 +0100
> +++ linux-2.6.35-rc3/include/media/omap1_camera.h	2010-07-18 01:31:57.000000000 +0200
> @@ -0,0 +1,16 @@

A copyright / licence header here, please

> +#ifndef __MEDIA_OMAP1_CAMERA_H_
> +#define __MEDIA_OMAP1_CAMERA_H_
> +
> +#define OMAP1_CAMERA_IOSIZE		0x1c
> +
> +struct omap1_cam_platform_data {
> +	unsigned long camexclk_khz;
> +	unsigned long lclk_khz_max;
> +	unsigned long flags;
> +};
> +
> +#define OMAP1_CAMERA_LCLK_RISING	BIT(0)
> +#define OMAP1_CAMERA_RST_LOW		BIT(1)
> +#define OMAP1_CAMERA_RST_HIGH		BIT(2)

Then you need to #include <linux/bitops.h>

> +
> +#endif /* __MEDIA_OMAP1_CAMERA_H_ */
> --- linux-2.6.35-rc3.orig/drivers/media/video/Kconfig	2010-06-26 15:55:29.000000000 +0200
> +++ linux-2.6.35-rc3/drivers/media/video/Kconfig	2010-07-02 04:12:02.000000000 +0200
> @@ -962,6 +962,20 @@ config VIDEO_SH_MOBILE_CEU
>  	---help---
>  	  This is a v4l2 driver for the SuperH Mobile CEU Interface
>  
> +config VIDEO_OMAP1
> +	tristate "OMAP1 Camera Interface driver"
> +	depends on VIDEO_DEV && ARCH_OMAP1 && SOC_CAMERA
> +	select VIDEOBUF_DMA_CONTIG if !VIDEO_OMAP1_SG
> +	---help---
> +	  This is a v4l2 driver for the TI OMAP1 camera interface
> +
> +if VIDEO_OMAP1

Don't think you need this "if," the "depends on" below should suffice.

> +config VIDEO_OMAP1_SG
> +	bool "Scatter-gather mode"
> +	depends on VIDEO_OMAP1 && EXPERIMENTAL
> +	select VIDEOBUF_DMA_SG
> +endif
> +
>  config VIDEO_OMAP2
>  	tristate "OMAP2 Camera Capture Interface driver"
>  	depends on VIDEO_DEV && ARCH_OMAP2
> --- linux-2.6.35-rc3.orig/drivers/media/video/Makefile	2010-06-26 15:55:29.000000000 +0200
> +++ linux-2.6.35-rc3/drivers/media/video/Makefile	2010-06-26 17:28:09.000000000 +0200
> @@ -165,6 +165,7 @@ obj-$(CONFIG_VIDEO_MX1)			+= mx1_camera.
>  obj-$(CONFIG_VIDEO_MX3)			+= mx3_camera.o
>  obj-$(CONFIG_VIDEO_PXA27x)		+= pxa_camera.o
>  obj-$(CONFIG_VIDEO_SH_MOBILE_CEU)	+= sh_mobile_ceu_camera.o
> +obj-$(CONFIG_VIDEO_OMAP1)		+= omap1_camera.o
>  
>  obj-$(CONFIG_ARCH_DAVINCI)		+= davinci/
>  
> --- linux-2.6.35-rc3.orig/drivers/media/video/omap1_camera.c	1970-01-01 01:00:00.000000000 +0100
> +++ linux-2.6.35-rc3/drivers/media/video/omap1_camera.c	2010-07-18 01:32:48.000000000 +0200
> @@ -0,0 +1,1656 @@
> +/*
> + * V4L2 SoC Camera driver for OMAP1 Camera Interface
> + *
> + * Copyright (C) 2010, Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
> + *
> + * Based on V4L2 Driver for i.MXL/i.MXL camera (CSI) host
> + * Copyright (C) 2008, Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
> + * Copyright (C) 2009, Darius Augulis <augulis.darius@gmail.com>
> + *
> + * Based on PXA SoC camera driver
> + * Copyright (C) 2006, Sascha Hauer, Pengutronix
> + * Copyright (C) 2008, Guennadi Liakhovetski <kernel@pengutronix.de>
> + *
> + * Hardware specific bits initialy based on former work by Matt Callow
> + * drivers/media/video/omap/omap1510cam.c
> + * Copyright (C) 2006 Matt Callow
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +
> +#include <linux/clk.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/interrupt.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/version.h>
> +
> +#include <media/omap1_camera.h>
> +#include <media/soc_camera.h>
> +#include <media/soc_mediabus.h>
> +#ifndef CONFIG_VIDEO_OMAP1_SG
> +#include <media/videobuf-dma-contig.h>
> +#else
> +#include <media/videobuf-dma-sg.h>
> +#endif

I think, you can just include both headers.

> +
> +#include <plat/dma.h>
> +
> +
> +#define DRIVER_NAME		"omap1-camera"
> +#define VERSION_CODE		KERNEL_VERSION(0, 0, 1)
> +
> +
> +/*
> + * ---------------------------------------------------------------------------
> + *  OMAP1 Camera Interface registers
> + * ---------------------------------------------------------------------------
> + */
> +
> +#define REG_CTRLCLOCK		0x00
> +#define REG_IT_STATUS		0x04
> +#define REG_MODE		0x08
> +#define REG_STATUS		0x0C
> +#define REG_CAMDATA		0x10
> +#define REG_GPIO		0x14
> +#define REG_PEAK_COUNTER	0x18
> +
> +/* CTRLCLOCK bit shifts */
> +#define LCLK_EN			BIT(7)
> +#define DPLL_EN			BIT(6)
> +#define MCLK_EN			BIT(5)
> +#define CAMEXCLK_EN		BIT(4)
> +#define POLCLK			BIT(3)
> +#define FOSCMOD_SHIFT		0
> +#define FOSCMOD_MASK		(0x7 << FOSCMOD_SHIFT)
> +#define FOSCMOD_12MHz		0x0
> +#define FOSCMOD_6MHz		0x2
> +#define FOSCMOD_9_6MHz		0x4
> +#define FOSCMOD_24MHz		0x5
> +#define FOSCMOD_8MHz		0x6
> +
> +/* IT_STATUS bit shifts */
> +#define DATA_TRANSFER		BIT(5)
> +#define FIFO_FULL		BIT(4)
> +#define H_DOWN			BIT(3)
> +#define H_UP			BIT(2)
> +#define V_DOWN			BIT(1)
> +#define V_UP			BIT(0)
> +
> +/* MODE bit shifts */
> +#define RAZ_FIFO		BIT(18)
> +#define EN_FIFO_FULL		BIT(17)
> +#define EN_NIRQ			BIT(16)
> +#define THRESHOLD_SHIFT		9
> +#define THRESHOLD_MASK		(0x7f << THRESHOLD_SHIFT)
> +#define DMA			BIT(8)
> +#define EN_H_DOWN		BIT(7)
> +#define EN_H_UP			BIT(6)
> +#define EN_V_DOWN		BIT(5)
> +#define EN_V_UP			BIT(4)
> +#define ORDERCAMD		BIT(3)
> +
> +#define IRQ_MASK		(EN_V_UP | EN_V_DOWN | EN_H_UP | EN_H_DOWN | \
> +				 EN_NIRQ | EN_FIFO_FULL)
> +
> +/* STATUS bit shifts */
> +#define HSTATUS			BIT(1)
> +#define VSTATUS			BIT(0)
> +
> +/* GPIO bit shifts */
> +#define CAM_RST			BIT(0)
> +
> +/* end of OMAP1 Camera Interface registers */
> +
> +
> +#define SOCAM_BUS_FLAGS	(SOCAM_MASTER | \
> +			SOCAM_HSYNC_ACTIVE_HIGH | SOCAM_VSYNC_ACTIVE_HIGH | \
> +			SOCAM_PCLK_SAMPLE_RISING | SOCAM_PCLK_SAMPLE_FALLING | \
> +			SOCAM_DATA_ACTIVE_HIGH | SOCAM_DATAWIDTH_8)
> +
> +
> +#define CAM_EXCLK_6MHz		 6000000
> +#define CAM_EXCLK_8MHz		 8000000
> +#define CAM_EXCLK_9_6MHz	 9600000
> +#define CAM_EXCLK_12MHz		12000000
> +#define CAM_EXCLK_24MHz		24000000

Why do you need this? Your platform specifies the EXCLK frequency directly 
in kHz, then you multiplly it by 1000 to get pcdev->camexclk in Hz, then 
you compare it to these macros. Don't think you need them - just use 
numbers directly.

> +
> +
> +#define FIFO_SIZE		((THRESHOLD_MASK >> THRESHOLD_SHIFT) + 1)
> +#define FIFO_SHIFT		__fls(FIFO_SIZE)
> +
> +#define DMA_BURST_SHIFT		(1 + OMAP_DMA_DATA_BURST_4)
> +#define DMA_BURST_SIZE		(1 << DMA_BURST_SHIFT)
> +
> +#define DMA_ELEMENT_SHIFT	OMAP_DMA_DATA_TYPE_S32
> +#define DMA_ELEMENT_SIZE	(1 << DMA_ELEMENT_SHIFT)
> +
> +#ifndef CONFIG_VIDEO_OMAP1_SG
> +#define DMA_FRAME_SHIFT		(FIFO_SHIFT - 1)
> +#define MIN_BUF_COUNT		3
> +#else
> +#define DMA_FRAME_SHIFT		DMA_BURST_SHIFT
> +#define MIN_BUF_COUNT		2
> +#endif
> +
> +#define DMA_FRAME_SIZE		(1 << DMA_FRAME_SHIFT)
> +#define DMA_SYNC		OMAP_DMA_SYNC_FRAME
> +#define THRESHOLD_LEVEL		DMA_FRAME_SIZE
> +
> +
> +#define MAX_VIDEO_MEM		4	/* arbitrary video memory limit in MB */
> +
> +
> +/*
> + * Structures
> + */
> +
> +/* buffer for one video frame */
> +struct omap1_cam_buf {
> +	struct videobuf_buffer		vb;
> +	enum v4l2_mbus_pixelcode	code;
> +	int				inwork;
> +#ifdef CONFIG_VIDEO_OMAP1_SG
> +	struct scatterlist		*sgbuf;
> +	int				sgcount;
> +	int				bytes_left;
> +	enum videobuf_state		result;
> +#endif
> +};
> +
> +struct omap1_cam_dev {
> +	struct soc_camera_host		soc_host;
> +	struct soc_camera_device	*icd;
> +	struct clk			*clk;
> +
> +	unsigned int			irq;
> +	void __iomem			*base;
> +
> +	int				dma_ch;
> +
> +	struct omap1_cam_platform_data	*pdata;
> +	struct resource			*res;
> +	unsigned long			pflags;
> +	unsigned long			camexclk;
> +
> +	struct list_head		capture;
> +
> +	spinlock_t			lock;
> +
> +	/* Pointers to DMA buffers */
> +	struct omap1_cam_buf		*active;
> +	struct omap1_cam_buf		*ready;

Well, I must confess, as it stands, you managed to confuse me with your 
"active" and "ready" buffer management. Is the reason for these two 
pointers some hardware feature? Maybe that while one buffer is being 
filled by DMA you can already configure the DMA engine with the next one?

> +
> +	u32			reg_cache[OMAP1_CAMERA_IOSIZE / sizeof(u32)];

Don't think you'd lose much performance without cache, for that the code 
would become less error-prone.

> +};
> +
> +
> +void cam_write(struct omap1_cam_dev *pcdev, u16 reg, u32 val)

static

> +{
> +	pcdev->reg_cache[reg / sizeof(u32)] = val;
> +	__raw_writel(val, pcdev->base + reg);
> +}
> +
> +int cam_read(struct omap1_cam_dev *pcdev, u16 reg, bool from_cache)

static u32

> +{
> +	return !from_cache ? __raw_readl(pcdev->base + reg) :
> +			pcdev->reg_cache[reg / sizeof(u32)];

hmmm.... it's never simple with caches;) Some registers (e.g., CTRLCLOCK) 
you read both from the cache and from the hardware directly. Don't you 
have to update the cache on a direct read?

> +}
> +
> +#define CAM_READ(pcdev, reg) \
> +		cam_read(pcdev, REG_##reg, 0)

last parameter is a bool, so, use "false"

> +#define CAM_WRITE(pcdev, reg, val) \
> +		cam_write(pcdev, REG_##reg, val)
> +#define CAM_READ_CACHE(pcdev, reg) \
> +		cam_read(pcdev, REG_##reg, 1)

"true"

> +
> +/*
> + *  Videobuf operations
> + */
> +static int omap1_videobuf_setup(struct videobuf_queue *vq, unsigned int *count,
> +		unsigned int *size)
> +{
> +	struct soc_camera_device *icd = vq->priv_data;
> +	int bytes_per_line = soc_mbus_bytes_per_line(icd->user_width,
> +			icd->current_fmt->host_fmt);
> +
> +	if (bytes_per_line < 0)
> +		return bytes_per_line;
> +
> +	*size = bytes_per_line * icd->user_height;
> +
> +	if (!*count || *count < MIN_BUF_COUNT)
> +		*count = MIN_BUF_COUNT;
> +
> +	if (*size * *count > MAX_VIDEO_MEM * 1024 * 1024)
> +		*count = (MAX_VIDEO_MEM * 1024 * 1024) / *size;
> +
> +	dev_dbg(icd->dev.parent,
> +			"%s: count=%d, size=%d\n", __func__, *count, *size);
> +
> +	return 0;
> +}
> +
> +static void free_buffer(struct videobuf_queue *vq, struct omap1_cam_buf *buf)
> +{
> +	struct videobuf_buffer *vb = &buf->vb;
> +#ifdef CONFIG_VIDEO_OMAP1_SG
> +	struct videobuf_dmabuf *dma = videobuf_to_dma(vb);
> +#endif
> +
> +	BUG_ON(in_interrupt());
> +
> +	videobuf_waiton(vb, 0, 0);
> +#ifndef CONFIG_VIDEO_OMAP1_SG
> +	videobuf_dma_contig_free(vq, vb);
> +#else
> +	videobuf_dma_unmap(vq, dma);
> +	videobuf_dma_free(dma);
> +#endif
> +
> +	vb->state = VIDEOBUF_NEEDS_INIT;
> +}
> +
> +static int omap1_videobuf_prepare(struct videobuf_queue *vq,
> +		struct videobuf_buffer *vb, enum v4l2_field field)
> +{
> +	struct soc_camera_device *icd = vq->priv_data;
> +	struct omap1_cam_buf *buf = container_of(vb, struct omap1_cam_buf, vb);
> +	int bytes_per_line = soc_mbus_bytes_per_line(icd->user_width,
> +			icd->current_fmt->host_fmt);
> +	int ret;
> +
> +	if (bytes_per_line < 0)
> +		return bytes_per_line;
> +
> +	WARN_ON(!list_empty(&vb->queue));
> +
> +	BUG_ON(NULL == icd->current_fmt);
> +
> +	buf->inwork = 1;
> +
> +	if (buf->code != icd->current_fmt->code ||
> +			vb->width  != icd->user_width ||
> +			vb->height != icd->user_height ||
> +			vb->field  != field) {
> +		buf->code  = icd->current_fmt->code;
> +		vb->width  = icd->user_width;
> +		vb->height = icd->user_height;
> +		vb->field  = field;
> +		vb->state  = VIDEOBUF_NEEDS_INIT;
> +	}
> +
> +	vb->size = bytes_per_line * vb->height;
> +
> +	if (vb->baddr && vb->bsize < vb->size) {
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	if (vb->state == VIDEOBUF_NEEDS_INIT) {
> +		ret = videobuf_iolock(vq, vb, NULL);
> +		if (ret)
> +			goto fail;
> +
> +		vb->state = VIDEOBUF_PREPARED;
> +	}
> +	buf->inwork = 0;
> +
> +	return 0;
> +fail:
> +	free_buffer(vq, buf);
> +out:
> +	buf->inwork = 0;
> +	return ret;
> +}
> +
> +static void set_dma_dest_params(int dma_ch, struct omap1_cam_buf *buf)
> +{
> +#ifndef CONFIG_VIDEO_OMAP1_SG
> +	dma_addr_t dma_addr = videobuf_to_dma_contig(&buf->vb);
> +	unsigned int block_size = buf->vb.size;
> +#else
> +	dma_addr_t dma_addr;
> +	unsigned int block_size;
> +
> +	if (WARN_ON(!buf->sgbuf)) {
> +		buf->result = VIDEOBUF_ERROR;
> +		return;
> +	}
> +	dma_addr = sg_dma_address(buf->sgbuf);
> +	if (WARN_ON(!dma_addr)) {
> +		buf->sgbuf = NULL;
> +		buf->result = VIDEOBUF_ERROR;
> +		return;
> +	}
> +	block_size = sg_dma_len(buf->sgbuf);
> +	if (WARN_ON(!block_size)) {
> +		buf->sgbuf = NULL;
> +		buf->result = VIDEOBUF_ERROR;
> +		return;
> +	}
> +	if (unlikely(buf->bytes_left < block_size))
> +		block_size = buf->bytes_left;
> +	if (WARN_ON(dma_addr & (DMA_FRAME_SIZE * DMA_ELEMENT_SIZE - 1))) {
> +		dma_addr = ALIGN(dma_addr, DMA_FRAME_SIZE * DMA_ELEMENT_SIZE);
> +		block_size &= ~(DMA_FRAME_SIZE * DMA_ELEMENT_SIZE - 1);
> +	}
> +	buf->bytes_left -= block_size;
> +	buf->sgcount++;
> +#endif
> +	omap_set_dma_dest_params(dma_ch, OMAP_DMA_PORT_EMIFF,
> +			OMAP_DMA_AMODE_POST_INC, dma_addr, 0, 0);
> +	omap_set_dma_transfer_params(dma_ch, OMAP_DMA_DATA_TYPE_S32,
> +			DMA_FRAME_SIZE, block_size >> (DMA_FRAME_SHIFT +
> +			DMA_ELEMENT_SHIFT), DMA_SYNC, 0, 0);
> +}
> +
> +#ifdef CONFIG_VIDEO_OMAP1_SG
> +static struct scatterlist *try_next_sgbuf(int dma_ch, struct omap1_cam_buf *buf)
> +{
> +	struct scatterlist *sgbuf;
> +
> +	if (likely(buf->sgbuf)) {
> +
> +		if (unlikely(!buf->bytes_left)) {
> +			/* indicate sglist complete */
> +			sgbuf = NULL;
> +		} else {
> +			sgbuf = sg_next(buf->sgbuf);
> +			if (WARN_ON(!sgbuf)) {
> +				buf->result = VIDEOBUF_ERROR;
> +			} else if (WARN_ON(!sg_dma_len(sgbuf))) {
> +				sgbuf = NULL;
> +				buf->result = VIDEOBUF_ERROR;
> +			}
> +		}
> +		buf->sgbuf = sgbuf;
> +	} else {
> +		struct videobuf_dmabuf *dma = videobuf_to_dma(&buf->vb);
> +
> +		buf->sgbuf = sgbuf = dma->sglist;
> +		if (sgbuf) {
> +			buf->sgcount = 0;
> +			buf->bytes_left = buf->vb.size;
> +			buf->result = VIDEOBUF_DONE;
> +		}
> +	}
> +	if (sgbuf)
> +		set_dma_dest_params(dma_ch, buf);
> +
> +	return sgbuf;
> +}
> +#endif
> +
> +static struct omap1_cam_buf *prepare_next_vb(struct omap1_cam_dev *pcdev)
> +{
> +	struct omap1_cam_buf *buf;
> +
> +	buf = pcdev->ready;
> +	if (!buf) {
> +		if (list_empty(&pcdev->capture))
> +			return buf;
> +		buf = list_entry(pcdev->capture.next,
> +				struct omap1_cam_buf, vb.queue);
> +		buf->vb.state = VIDEOBUF_ACTIVE;
> +		pcdev->ready = buf;
> +		list_del_init(&buf->vb.queue);
> +	}
> +#ifndef CONFIG_VIDEO_OMAP1_SG
> +	set_dma_dest_params(pcdev->dma_ch, buf);
> +#else
> +	buf->sgbuf = NULL;
> +#endif
> +	return buf;
> +}
> +
> +static void start_capture(struct omap1_cam_dev *pcdev)
> +{
> +	struct omap1_cam_buf *buf = pcdev->active;
> +	unsigned long ctrlclock = CAM_READ_CACHE(pcdev, CTRLCLOCK);
> +	unsigned long mode = CAM_READ_CACHE(pcdev, MODE);

I would make all variables, that are used specifically for various 
registers u32.

> +
> +	if (WARN_ON(!buf))
> +		return;
> +
> +#ifndef CONFIG_VIDEO_OMAP1_SG
> +	/* don't enable end of frame interrupts before capture autostart */
> +	mode &= ~EN_V_DOWN;
> +#endif
> +	if (WARN_ON(mode & RAZ_FIFO))
> +		/*  clean up possibly insane reset condition */
> +		CAM_WRITE(pcdev, MODE, mode &= ~RAZ_FIFO);

It is usually better to avoid assigning variables inside other constructs, 
please split into two lines. Besides, in omap1_cam_probe() you initialise 
MODE to "THRESHOLD_LEVEL << THRESHOLD_SHIFT," i.e., RAZ_FIFO is cleared. 
So, don't think you need that test at all.

> +
> +	if (unlikely(ctrlclock & LCLK_EN))
> +		/* stop pixel clock before FIFO reset */
> +		CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock & ~LCLK_EN);
> +	/* reset FIFO */
> +	CAM_WRITE(pcdev, MODE, mode | RAZ_FIFO);
> +
> +	omap_start_dma(pcdev->dma_ch);
> +
> +	/* (re)enable pixel clock */
> +	CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock | LCLK_EN);
> +	/* release FIFO reset */
> +	CAM_WRITE(pcdev, MODE, mode);
> +
> +#ifdef CONFIG_VIDEO_OMAP1_SG
> +	try_next_sgbuf(pcdev->dma_ch, buf);
> +#endif
> +}
> +
> +static void suspend_capture(struct omap1_cam_dev *pcdev)
> +{
> +	unsigned long ctrlclock = CAM_READ_CACHE(pcdev, CTRLCLOCK);

u32

> +
> +	CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock & ~LCLK_EN);
> +	omap_stop_dma(pcdev->dma_ch);
> +}
> +
> +static void disable_capture(struct omap1_cam_dev *pcdev)
> +{
> +	unsigned long mode = CAM_READ_CACHE(pcdev, MODE);

u32 (etc.)

> +
> +	CAM_WRITE(pcdev, MODE, mode & ~(IRQ_MASK | DMA));
> +}
> +
> +static void omap1_videobuf_queue(struct videobuf_queue *vq,
> +						struct videobuf_buffer *vb)
> +{
> +	struct soc_camera_device *icd = vq->priv_data;
> +	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
> +	struct omap1_cam_dev *pcdev = ici->priv;
> +	struct omap1_cam_buf *buf;
> +	unsigned long mode;
> +
> +	list_add_tail(&vb->queue, &pcdev->capture);
> +	vb->state = VIDEOBUF_QUEUED;
> +
> +	if (pcdev->active)
> +		return;
> +
> +	WARN_ON(pcdev->ready);
> +
> +	buf = prepare_next_vb(pcdev);
> +	if (WARN_ON(!buf))
> +		return;
> +
> +	pcdev->active = buf;
> +	pcdev->ready = NULL;
> +
> +	dev_dbg(icd->dev.parent, "%s: capture not active, setup FIFO, start DMA"
> +			"\n", __func__);

No need to split "\n" to a new line, don't worry about > 80 characters...

> +	mode = CAM_READ_CACHE(pcdev, MODE) & (THRESHOLD_MASK | ORDERCAMD);
> +	mode |= EN_FIFO_FULL | DMA;
> +#ifndef CONFIG_VIDEO_OMAP1_SG
> +	CAM_WRITE(pcdev, MODE, mode | EN_V_UP);
> +#else
> +	CAM_WRITE(pcdev, MODE, mode | EN_V_DOWN);
> +
> +	try_next_sgbuf(pcdev->dma_ch, buf);
> +#endif
> +	start_capture(pcdev);
> +}
> +
> +static void omap1_videobuf_release(struct videobuf_queue *vq,
> +				 struct videobuf_buffer *vb)
> +{
> +	struct omap1_cam_buf *buf =
> +			container_of(vb, struct omap1_cam_buf, vb);
> +	struct soc_camera_device *icd = vq->priv_data;
> +	struct device *dev = icd->dev.parent;
> +
> +	switch (vb->state) {
> +	case VIDEOBUF_DONE:
> +		dev_dbg(dev, "%s (done)\n", __func__);
> +		break;
> +	case VIDEOBUF_ACTIVE:
> +		dev_dbg(dev, "%s (active)\n", __func__);
> +		break;
> +	case VIDEOBUF_QUEUED:
> +		dev_dbg(dev, "%s (queued)\n", __func__);
> +		break;
> +	case VIDEOBUF_PREPARED:
> +		dev_dbg(dev, "%s (prepared)\n", __func__);
> +		break;
> +	default:
> +		dev_dbg(dev, "%s (unknown)\n", __func__);
> +		break;
> +	}
> +
> +	free_buffer(vq, buf);
> +}
> +
> +static void videobuf_done(struct omap1_cam_dev *pcdev,
> +		enum videobuf_state result)
> +{
> +	struct omap1_cam_buf *buf = pcdev->active;
> +	struct videobuf_buffer *vb;
> +	struct device *dev = pcdev->icd->dev.parent;
> +
> +	if (WARN_ON(!buf)) {
> +		suspend_capture(pcdev);
> +		disable_capture(pcdev);
> +		return;
> +	}
> +
> +	if (result == VIDEOBUF_ERROR)
> +		suspend_capture(pcdev);
> +
> +	vb = &buf->vb;
> +	if (waitqueue_active(&vb->done)) {

I'm not sure this is a good idea. Why are you reusing the buffer, if noone 
is waiting for it _now_? It can well be, that the task is doing something 
else atm. Like processing the previous frame. Or it has been preempted by 
another process, before it called poll() or select() on your device?

> +		if (!pcdev->ready && result != VIDEOBUF_ERROR)
> +			suspend_capture(pcdev);
> +		vb->state = result;
> +		do_gettimeofday(&vb->ts);
> +		vb->field_count++;

I don't think you're supposed to increment field_count if you've got a 
VIDEOBUF_ERROR.

> +		wake_up(&vb->done);
> +
> +		pcdev->active = buf = pcdev->ready;
> +		pcdev->ready = NULL;
> +
> +		if (!buf) {
> +			result = VIDEOBUF_ERROR;
> +			prepare_next_vb(pcdev);
> +
> +			pcdev->active = buf = pcdev->ready;
> +			pcdev->ready = NULL;
> +		}
> +	} else if (pcdev->ready) {
> +		dev_dbg(dev, "%s: nobody waiting on videobuf, swap with next\n",
> +				__func__);

Not sure this is a wise decision... If there are more buffers in the 
queue, they stay there waiting. Best remove this waitqueue_active() check 
entirely, just complete buffers and wake up the user regardless. If no 
more buffers - go to sleep.

> +		pcdev->active = pcdev->ready;
> +#ifdef CONFIG_VIDEO_OMAP1_SG
> +		buf->sgbuf = NULL;
> +#endif
> +		pcdev->ready = buf;
> +
> +		buf = pcdev->active;
> +	} else {
> +#ifndef CONFIG_VIDEO_OMAP1_SG
> +		dev_dbg(dev, "%s: nobody waiting on videobuf, reuse it\n",
> +				__func__);
> +#else
> +		if (result != VIDEOBUF_ERROR) {
> +			suspend_capture(pcdev);
> +			result = VIDEOBUF_ERROR;
> +		}
> +		prepare_next_vb(pcdev);
> +#endif
> +	}
> +
> +	if (!buf) {
> +		dev_dbg(dev, "%s: no more videobufs, stop capture\n", __func__);
> +		disable_capture(pcdev);
> +		return;
> +	}
> +
> +#ifdef CONFIG_VIDEO_OMAP1_SG
> +	if (result == VIDEOBUF_ERROR)
> +		buf->sgbuf = NULL;
> +
> +	try_next_sgbuf(pcdev->dma_ch, buf);
> +#endif
> +
> +	if (result == VIDEOBUF_ERROR) {
> +		dev_dbg(dev, "%s: videobuf error; reset FIFO, restart DMA\n",
> +				__func__);
> +		start_capture(pcdev);
> +	}

This all doesn't look quite right, but I'll wait for documentation, before 
commenting.

> +
> +	prepare_next_vb(pcdev);
> +}
> +
> +static void dma_isr(int channel, unsigned short status, void *data)
> +{
> +	struct omap1_cam_dev *pcdev = data;
> +	struct omap1_cam_buf *buf = pcdev->active;
> +	enum videobuf_state result;
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&pcdev->lock, flags);
> +
> +	if (WARN_ON(!buf)) {
> +		suspend_capture(pcdev);
> +		disable_capture(pcdev);
> +		goto out;
> +	}
> +
> +#ifndef CONFIG_VIDEO_OMAP1_SG
> +	/* videobuf complete, disable end of frame interrupt for this frame */
> +	CAM_WRITE(pcdev, MODE, CAM_READ_CACHE(pcdev, MODE) & ~EN_V_DOWN);
> +	result = VIDEOBUF_DONE;
> +#else
> +	if (buf->sgbuf) {
> +		/* current sglist not complete yet */
> +		try_next_sgbuf(pcdev->dma_ch, buf);
> +		if (buf->sgbuf)
> +			goto out;
> +
> +		if (buf->result != VIDEOBUF_ERROR) {
> +			buf = prepare_next_vb(pcdev);
> +			if (!buf)
> +				goto out;
> +
> +			try_next_sgbuf(pcdev->dma_ch, buf);
> +			goto out;
> +		}
> +	}
> +	/* end of videobuf */
> +	result = buf->result;
> +#endif
> +	videobuf_done(pcdev, result);
> +out:
> +	spin_unlock_irqrestore(&pcdev->lock, flags);
> +}
> +
> +static irqreturn_t cam_isr(int irq, void *data)
> +{
> +	struct omap1_cam_dev *pcdev = data;
> +	struct device *dev = pcdev->icd->dev.parent;
> +	struct omap1_cam_buf *buf = pcdev->active;
> +	unsigned long it_status;
> +	unsigned long flags;
> +
> +	it_status = CAM_READ(pcdev, IT_STATUS);
> +	if (!it_status)
> +		return IRQ_NONE;
> +
> +	spin_lock_irqsave(&pcdev->lock, flags);
> +
> +	if (WARN_ON(!buf)) {
> +		suspend_capture(pcdev);
> +		disable_capture(pcdev);
> +		goto out;
> +	}
> +
> +	if (unlikely(it_status & FIFO_FULL)) {
> +		dev_warn(dev, "%s: FIFO overflow\n", __func__);
> +
> +	} else if (it_status & V_DOWN) {
> +#ifdef CONFIG_VIDEO_OMAP1_SG
> +		/*
> +		 * if exactly 2 sgbufs of the next sglist has be used,
> +		 * then we are in sync
> +		 */

You mean the hardware is supposed to interrupt you after 2 buffers?

> +		if (buf && buf->sgcount == 2)
> +			goto out;
> +#endif
> +		dev_notice(dev, "%s: unexpected end of video frame\n",
> +				__func__);
> +
> +#ifndef CONFIG_VIDEO_OMAP1_SG
> +	} else if (it_status & V_UP) {
> +		unsigned long mode = CAM_READ_CACHE(pcdev, MODE);
> +
> +		if (!(mode & EN_V_DOWN)) {
> +			/* enable end of frame interrupt for current videobuf */
> +			CAM_WRITE(pcdev, MODE, mode | EN_V_DOWN);
> +		}
> +		goto out;
> +#endif
> +
> +	} else {
> +		dev_warn(pcdev->soc_host.v4l2_dev.dev, "%s: "
> +				"unhandled camera interrupt, status == 0x%lx\n",
> +				__func__, it_status);
> +		goto out;
> +	}
> +
> +	videobuf_done(pcdev, VIDEOBUF_ERROR);
> +out:
> +	spin_unlock_irqrestore(&pcdev->lock, flags);
> +	return IRQ_HANDLED;
> +}
> +
> +static struct videobuf_queue_ops omap1_videobuf_ops = {
> +	.buf_setup	= omap1_videobuf_setup,
> +	.buf_prepare	= omap1_videobuf_prepare,
> +	.buf_queue	= omap1_videobuf_queue,
> +	.buf_release	= omap1_videobuf_release,
> +};
> +
> +
> +/*
> + * SOC Camera host operations
> + */
> +
> +static void sensor_reset(struct omap1_cam_dev *pcdev, bool reset)
> +{
> +	/* apply/release camera sensor reset if requested by platform data */
> +	if (pcdev->pflags & OMAP1_CAMERA_RST_HIGH)
> +		CAM_WRITE(pcdev, GPIO, reset);
> +	else if (pcdev->pflags & OMAP1_CAMERA_RST_LOW)
> +		CAM_WRITE(pcdev, GPIO, !reset);
> +}
> +
> +/*
> + * The following two functions absolutely depend on the fact, that
> + * there can be only one camera on OMAP1 camera sensor interface
> + */
> +static int omap1_cam_add_device(struct soc_camera_device *icd)
> +{
> +	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
> +	struct omap1_cam_dev *pcdev = ici->priv;
> +	unsigned int ctrlclock;

u32

> +	int ret = 0;
> +
> +	if (pcdev->icd) {
> +		ret = -EBUSY;
> +		goto ebusy;
> +	}
> +
> +	clk_enable(pcdev->clk);
> +
> +	/* setup sensor clock */
> +	ctrlclock = CAM_READ(pcdev, CTRLCLOCK);
> +	ctrlclock &= ~(CAMEXCLK_EN | MCLK_EN | DPLL_EN);
> +	CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock);
> +
> +	ctrlclock &= ~FOSCMOD_MASK;
> +	switch (pcdev->camexclk) {
> +	case CAM_EXCLK_6MHz:

just use constants for these

> +		ctrlclock |= CAMEXCLK_EN | FOSCMOD_6MHz;
> +		break;
> +	case CAM_EXCLK_8MHz:
> +		ctrlclock |= CAMEXCLK_EN | FOSCMOD_8MHz | DPLL_EN;
> +		break;
> +	case CAM_EXCLK_9_6MHz:
> +		ctrlclock |= CAMEXCLK_EN | FOSCMOD_9_6MHz | DPLL_EN;
> +		break;
> +	case CAM_EXCLK_12MHz:
> +		ctrlclock |= CAMEXCLK_EN | FOSCMOD_12MHz;
> +		break;
> +	case CAM_EXCLK_24MHz:
> +		ctrlclock |= CAMEXCLK_EN | FOSCMOD_24MHz | DPLL_EN;
> +	default:

This is the case of "Not providing sensor clock," do you still have to 
enable the clock at all below (MCLK_EN)?

> +		break;
> +	}
> +	CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock & ~DPLL_EN);
> +
> +	/* enable clock */
> +	ctrlclock |= MCLK_EN;
> +	CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock);
> +
> +	sensor_reset(pcdev, 0);

use "false" for the second parameter

> +
> +	pcdev->icd = icd;
> +
> +	dev_info(icd->dev.parent, "OMAP1 Camera driver attached to camera %d\n",
> +		 icd->devnum);
> +ebusy:
> +	return ret;
> +}
> +
> +static void omap1_cam_remove_device(struct soc_camera_device *icd)
> +{
> +	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
> +	struct omap1_cam_dev *pcdev = ici->priv;
> +	unsigned long ctrlclock;
> +
> +	BUG_ON(icd != pcdev->icd);
> +
> +	suspend_capture(pcdev);
> +	disable_capture(pcdev);
> +
> +	sensor_reset(pcdev, 1);
> +
> +	/* disable and release system clocks */
> +	ctrlclock = CAM_READ(pcdev, CTRLCLOCK);
> +	ctrlclock &= ~(MCLK_EN | DPLL_EN | CAMEXCLK_EN);
> +	CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock);
> +
> +	ctrlclock = (ctrlclock & ~FOSCMOD_MASK) | FOSCMOD_12MHz;
> +	CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock);
> +	CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock | MCLK_EN);
> +
> +	CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock & ~MCLK_EN);
> +
> +	clk_disable(pcdev->clk);
> +
> +	pcdev->icd = NULL;
> +
> +	dev_info(icd->dev.parent, "OMAP1 Camera driver detached from camera %d"
> +			"\n", icd->devnum);
> +}
> +
> +/* Duplicate standard formats based on host capability of byte swapping */
> +static const struct soc_mbus_pixelfmt omap1_cam_formats[] = {
> +	[V4L2_MBUS_FMT_YUYV8_2X8_BE] = {

You'll have to adjust these to the new names. Basically, for all YUYV8 and 
YVYU8 codes, "_LE" just gets dropped, and for "_BE" you swap 
chrominance-luminance pairs, i.e., UYVY8_2X8 instead of YUYV8_2X8_BE and 
VYUY8_2X8 instead of YVYU8_2X8_BE.

> +		.fourcc			= V4L2_PIX_FMT_YUYV,
> +		.name			= "YUYV",
> +		.bits_per_sample	= 8,
> +		.packing		= SOC_MBUS_PACKING_2X8_PADHI,
> +		.order			= SOC_MBUS_ORDER_BE,
> +	},
> +	[V4L2_MBUS_FMT_YVYU8_2X8_BE] = {
> +		.fourcc			= V4L2_PIX_FMT_YVYU,
> +		.name			= "YVYU",
> +		.bits_per_sample	= 8,
> +		.packing		= SOC_MBUS_PACKING_2X8_PADHI,
> +		.order			= SOC_MBUS_ORDER_BE,
> +	},
> +	[V4L2_MBUS_FMT_YUYV8_2X8_LE] = {
> +		.fourcc			= V4L2_PIX_FMT_UYVY,
> +		.name			= "UYVY",
> +		.bits_per_sample	= 8,
> +		.packing		= SOC_MBUS_PACKING_2X8_PADHI,
> +		.order			= SOC_MBUS_ORDER_BE,
> +	},
> +	[V4L2_MBUS_FMT_YVYU8_2X8_LE] = {
> +		.fourcc			= V4L2_PIX_FMT_VYUY,
> +		.name			= "VYUY",
> +		.bits_per_sample	= 8,
> +		.packing		= SOC_MBUS_PACKING_2X8_PADHI,
> +		.order			= SOC_MBUS_ORDER_BE,
> +	},
> +	[V4L2_MBUS_FMT_RGB555_2X8_PADHI_BE] = {
> +		.fourcc			= V4L2_PIX_FMT_RGB555,
> +		.name			= "RGB555",
> +		.bits_per_sample	= 8,
> +		.packing		= SOC_MBUS_PACKING_2X8_PADHI,
> +		.order			= SOC_MBUS_ORDER_BE,
> +	},
> +	[V4L2_MBUS_FMT_RGB555_2X8_PADHI_LE] = {
> +		.fourcc			= V4L2_PIX_FMT_RGB555X,
> +		.name			= "RGB555X",
> +		.bits_per_sample	= 8,
> +		.packing		= SOC_MBUS_PACKING_2X8_PADHI,
> +		.order			= SOC_MBUS_ORDER_BE,
> +	},
> +	[V4L2_MBUS_FMT_RGB565_2X8_BE] = {
> +		.fourcc			= V4L2_PIX_FMT_RGB565,
> +		.name			= "RGB565",
> +		.bits_per_sample	= 8,
> +		.packing		= SOC_MBUS_PACKING_2X8_PADHI,
> +		.order			= SOC_MBUS_ORDER_BE,
> +	},
> +	[V4L2_MBUS_FMT_RGB565_2X8_LE] = {
> +		.fourcc			= V4L2_PIX_FMT_RGB565X,
> +		.name			= "RGB565X",
> +		.bits_per_sample	= 8,
> +		.packing		= SOC_MBUS_PACKING_2X8_PADHI,
> +		.order			= SOC_MBUS_ORDER_BE,
> +	},
> +};
> +
> +static int omap1_cam_get_formats(struct soc_camera_device *icd,
> +		unsigned int idx, struct soc_camera_format_xlate *xlate)
> +{
> +	struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
> +	struct device *dev = icd->dev.parent;
> +	int formats = 0, ret;
> +	enum v4l2_mbus_pixelcode code;
> +	const struct soc_mbus_pixelfmt *fmt;
> +
> +	ret = v4l2_subdev_call(sd, video, enum_mbus_fmt, idx, &code);
> +	if (ret < 0)
> +		/* No more formats */
> +		return 0;
> +
> +	fmt = soc_mbus_get_fmtdesc(code);
> +	if (!fmt) {
> +		dev_err(dev, "%s: invalid format code #%d: %d\n", __func__,
> +				idx, code);
> +		return 0;
> +	}
> +
> +	/* Check support for the requested bits-per-sample */
> +	if (fmt->bits_per_sample != 8)
> +		return 0;
> +
> +	switch (code) {
> +	case V4L2_MBUS_FMT_YUYV8_2X8_BE:
> +	case V4L2_MBUS_FMT_YVYU8_2X8_BE:
> +	case V4L2_MBUS_FMT_YUYV8_2X8_LE:
> +	case V4L2_MBUS_FMT_YVYU8_2X8_LE:
> +	case V4L2_MBUS_FMT_RGB555_2X8_PADHI_BE:
> +	case V4L2_MBUS_FMT_RGB555_2X8_PADHI_LE:
> +	case V4L2_MBUS_FMT_RGB565_2X8_BE:
> +	case V4L2_MBUS_FMT_RGB565_2X8_LE:
> +		formats++;
> +		if (xlate) {
> +			xlate->host_fmt	= &omap1_cam_formats[code];
> +			xlate->code	= code;
> +			xlate++;
> +			dev_dbg(dev, "%s: providing format %s "
> +					"as byte swapped code #%d\n", __func__,
> +					omap1_cam_formats[code].name, code);
> +		}
> +	default:
> +		if (xlate)
> +			dev_dbg(dev, "%s: providing format %s "
> +					"in pass-through mode\n", __func__,
> +					fmt->name);
> +	}
> +	formats++;
> +	if (xlate) {
> +		xlate->host_fmt	= fmt;
> +		xlate->code	= code;
> +		xlate++;
> +	}
> +
> +	return formats;
> +}
> +
> +static int is_dma_aligned(s32 bytes_per_line, unsigned int height)

make it a bool

> +{
> +	int size = bytes_per_line * height;
> +
> +	return IS_ALIGNED(bytes_per_line, DMA_ELEMENT_SIZE) &&
> +			IS_ALIGNED(size, DMA_FRAME_SIZE * DMA_ELEMENT_SIZE);
> +}
> +
> +static int dma_align(int *width, int *height,
> +		const struct soc_mbus_pixelfmt *fmt, bool enlarge)
> +{
> +	s32 bytes_per_line = soc_mbus_bytes_per_line(*width, fmt);
> +
> +	if (bytes_per_line < 0)
> +		return bytes_per_line;
> +
> +	if (!is_dma_aligned(bytes_per_line, *height)) {
> +		unsigned int pxalign = __fls(bytes_per_line / *width);
> +		unsigned int salign  =
> +				DMA_FRAME_SHIFT + DMA_ELEMENT_SHIFT - pxalign;
> +		unsigned int incr    = enlarge << salign;
> +
> +		v4l_bound_align_image(width, DMA_ELEMENT_SIZE >> pxalign,
> +				*width + incr, DMA_ELEMENT_SHIFT - pxalign,

The above means, that lines must consist of an integer number of DMA 
elements, right? Is this really necessary?

> +				height, 1, *height + incr, 0, salign);
> +		return 0;
> +	}
> +	return 1;
> +}
> +
> +/* returns 1 on g_crop() success, 0 on cropcap() success, <0 on error */
> +static int get_crop(struct soc_camera_device *icd, struct v4l2_rect *rect)
> +{
> +	struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
> +	struct device *dev = icd->dev.parent;
> +	struct v4l2_crop crop;
> +	int ret;
> +
> +	crop.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
> +	ret = v4l2_subdev_call(sd, video, g_crop, &crop);
> +	if (ret == -ENOIOCTLCMD) {
> +		struct v4l2_cropcap cc;
> +
> +		dev_dbg(dev, "%s: g_crop() missing, trying cropcap() instead"
> +				"\n", __func__);

Put "\n" back in the string

> +		cc.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
> +		ret = v4l2_subdev_call(sd, video, cropcap, &cc);
> +		if (ret < 0)
> +			return ret;
> +		*rect = cc.defrect;
> +		return 0;
> +	} else if (ret < 0) {
> +		return ret;
> +	}
> +	*rect  = crop.c;

superfluous space

> +	return 1;
> +}
> +
> +/*
> + * returns 1 on g_mbus_fmt() or g_crop() success, 0 on cropcap() success,
> + * <0 on error
> + */
> +static int get_geometry(struct soc_camera_device *icd, struct v4l2_rect *rect,
> +		enum v4l2_mbus_pixelcode code)
> +{
> +	struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
> +	struct device *dev = icd->dev.parent;
> +	struct v4l2_mbus_framefmt mf;
> +	int ret;
> +
> +	ret = v4l2_subdev_call(sd, video, g_mbus_fmt, &mf);
> +	if (ret == -ENOIOCTLCMD) {
> +		struct v4l2_rect c;
> +
> +		dev_dbg(dev, "%s: g_mbus_fmt() missing, trying g_crop() instead"
> +				"\n", __func__);

Put "\n" back in the string

> +		ret = get_crop(icd, &c);
> +		if (ret < 0)
> +			return ret;
> +		/* REVISIT:
> +		 * Should cropcap() obtained defrect reflect last s_crop()?
> +		 * Can we use it here for s_crop() result verification?
> +		 */

multiline comment style

> +		if (ret) {
> +			*rect = c;	/* use g_crop() result */
> +		} else {
> +			dev_warn(dev, "%s: current geometry not available\n",
> +					__func__);
> +			return 0;
> +		}
> +	} else if (ret < 0) {
> +		return ret;
> +	} else if (mf.code != code) {
> +		return -EINVAL;
> +	} else {
> +		rect->width  = mf.width;
> +		rect->height = mf.height;
> +	}
> +	return 1;
> +}
> +
> +#define subdev_call_with_sense(ret, function, args...) \
> +{ \
> +	struct soc_camera_sense sense = { \
> +		.master_clock		= pcdev->camexclk, \
> +		.pixel_clock_max	= 0, \
> +	}; \
> +\
> +	if (pcdev->pdata) \
> +		sense.pixel_clock_max = pcdev->pdata->lclk_khz_max * 1000; \
> +	icd->sense = &sense; \
> +	*(ret) = v4l2_subdev_call(sd, video, function, ##args); \
> +	icd->sense = NULL; \
> +\
> +	if (sense.flags & SOCAM_SENSE_PCLK_CHANGED) { \
> +		if (sense.pixel_clock > sense.pixel_clock_max) { \
> +			dev_err(dev, "%s: " \
> +				"pixel clock %lu set by the camera too high!" \
> +				"\n", __func__, sense.pixel_clock); \

"\n" back, please

> +			return -EIO; \
> +		} \
> +	} \
> +}

Ok, I'd prefer to follow some good-style rules here too. (1) please align 
your backslashes with TABs. (2) please, don't use implicitly passed 
variables, in this case "sd," "pcdev," "dev," and "icd." (3) since this is 
a macro, you don't need to pass ret as a pointer. (4) don't "return" from 
a macro - in your case it's enough to "ret = -EIO." Personally, I wouldn't 
worry about adding 4 more parameters to the macro. I would also remove 
"ret" from parameters and "return" it from the macro per

#define subdev_call_with_sense(pcdev, dev, icd, sd, function, args...)	\
({									\
	int __ret;							\
	...								\
	__ret = v4l2_subdev_call(sd, video, function, ##args);		\
	...								\
			__ret = -EINVAL;				\
	...								\
	__ret;								\
})

> +
> +static int omap1_cam_set_crop(struct soc_camera_device *icd,
> +			       struct v4l2_crop *crop)
> +{
> +	struct v4l2_rect *rect = &crop->c;
> +	struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
> +	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
> +	struct omap1_cam_dev *pcdev = ici->priv;
> +	struct device *dev = icd->dev.parent;
> +	s32 bytes_per_line;
> +	int ret;
> +
> +	ret = dma_align(&rect->width, &rect->height, icd->current_fmt->host_fmt,
> +			false);
> +	if (ret < 0) {
> +		dev_err(dev, "%s: failed to align %ux%u %s with DMA\n",
> +				__func__, rect->width, rect->height,
> +				icd->current_fmt->host_fmt->name);
> +		return ret;
> +	}
> +
> +	subdev_call_with_sense(&ret, s_crop, crop);
> +	if (ret < 0) {
> +		dev_warn(dev, "%s: failed to crop to %ux%u@%u:%u\n", __func__,
> +			 rect->width, rect->height, rect->left, rect->top);
> +		return ret;
> +	}
> +
> +	ret = get_geometry(icd, rect, icd->current_fmt->code);
> +	if (ret < 0) {
> +		dev_err(dev, "%s: get_geometry() failed\n", __func__);
> +		return ret;
> +	}
> +	if (!ret) {
> +		dev_warn(dev, "%s: unable to verify s_crop() results\n",
> +				__func__);
> +	}

Superfluous braces

> +
> +	bytes_per_line = soc_mbus_bytes_per_line(rect->width,
> +			icd->current_fmt->host_fmt);
> +	if (bytes_per_line < 0) {
> +		dev_err(dev, "%s: soc_mbus_bytes_per_line() failed\n",
> +				__func__);
> +		return bytes_per_line;
> +	}
> +
> +	ret = is_dma_aligned(bytes_per_line, rect->height);
> +	if (ret < 0) {

Doesn't look like this is possible.

> +		dev_err(dev, "%s: is_dma_aligned() failed\n", __func__);
> +		return ret;
> +	}
> +	if (!ret) {
> +		dev_err(dev, "%s: resulting geometry %dx%d not DMA aligned\n",
> +				__func__, rect->width, rect->height);
> +		return -EINVAL;
> +	}
> +
> +	icd->user_width	 = rect->width;
> +	icd->user_height = rect->height;

No, this is wrong. user_width and user_height are _user_ sizes, i.e., a 
result sensor cropping and scaling and host cropping and scaling. Whereas 
set_crop sets sensor input rectangle.

> +
> +	return ret;
> +}
> +
> +static int omap1_cam_set_fmt(struct soc_camera_device *icd,
> +			      struct v4l2_format *f)
> +{
> +	struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
> +	const struct soc_camera_format_xlate *xlate;
> +	struct device *dev = icd->dev.parent;
> +	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
> +	struct omap1_cam_dev *pcdev = ici->priv;
> +	struct v4l2_pix_format *pix = &f->fmt.pix;
> +	struct v4l2_mbus_framefmt mf;
> +	struct v4l2_crop crop;
> +	struct v4l2_rect *rect = &crop.c;
> +	int bytes_per_line;
> +	int ret;
> +
> +	xlate = soc_camera_xlate_by_fourcc(icd, pix->pixelformat);
> +	if (!xlate) {
> +		dev_warn(dev, "%s: format %x not found\n", __func__,
> +				pix->pixelformat);
> +		return -EINVAL;
> +	}
> +
> +	bytes_per_line = soc_mbus_bytes_per_line(pix->width, xlate->host_fmt);
> +	if (bytes_per_line < 0) {
> +		dev_err(dev, "%s: soc_mbus_bytes_per_line() failed\n",
> +				__func__);
> +		return bytes_per_line;
> +	}
> +	if (pix->bytesperline && pix->bytesperline != bytes_per_line) {
> +		dev_err(dev, "%s: bytes per line mismatch\n", __func__);
> +		return -EINVAL;
> +	}
> +	ret = is_dma_aligned(bytes_per_line, pix->height);
> +	if (ret < 0) {

ditto - that's just a bool.

> +		dev_err(dev, "%s: is_dma_aligned() failed\n", __func__);
> +		return ret;
> +	}
> +	if (!ret) {
> +		dev_err(dev, "%s: image size %dx%d not DMA aligned\n",
> +				__func__, pix->width, pix->height);
> +		return -EINVAL;
> +	}
> +
> +	mf.width	= pix->width;
> +	mf.height	= pix->height;
> +	mf.field	= pix->field;
> +	mf.colorspace	= pix->colorspace;
> +	mf.code		= xlate->code;
> +
> +	subdev_call_with_sense(&ret, s_mbus_fmt, &mf);
> +	if (ret < 0) {
> +		dev_err(dev, "%s: failed to set format\n", __func__);
> +		return ret;
> +	}
> +
> +	if (mf.code != xlate->code) {
> +		dev_err(dev, "%s: unexpected pixel code change\n", __func__);
> +		return -EINVAL;
> +	}
> +	icd->current_fmt = xlate;
> +
> +	pix->field	= mf.field;
> +	pix->colorspace	= mf.colorspace;
> +
> +	if (mf.width == pix->width && mf.height == pix->height)
> +		return 0;
> +
> +	dev_notice(dev, "%s: sensor geometry differs, trying to crop to %dx%d"
> +			"\n", __func__, pix->width, pix->height);

No, you shouldn't do this. It is normal, when S_FMT sets a format 
different from what the user has requested. Just leave it as is, only 
adjust if you cannot handle it or fail.

> +	crop.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
> +	ret = get_crop(icd, rect);
> +	if (ret < 0) {
> +		dev_err(dev, "%s: get_crop() failed\n", __func__);
> +		return ret;
> +	}
> +
> +	rect->width  = pix->width;
> +	rect->height = pix->height;
> +
> +	subdev_call_with_sense(&ret, s_crop, &crop);
> +	if (ret < 0) {
> +		dev_warn(dev, "%s: failed to crop to %ux%u@%u:%u\n", __func__,
> +			 rect->width, rect->height, rect->left, rect->top);
> +		return ret;
> +	}
> +
> +	ret = get_geometry(icd, rect, xlate->code);
> +	if (ret < 0) {
> +		dev_err(dev, "%s: get_geometry() failed\n", __func__);
> +		return ret;
> +	}
> +
> +	if (!ret) {
> +		dev_warn(dev, "%s: s_crop() results not verified\n", __func__);
> +		return 0;
> +	}
> +
> +	if (pix->width != rect->width || pix->height != rect->height) {
> +		dev_err(dev, "%s: tried to set %dx%d, got %dx%d\n", __func__,
> +				pix->width, pix->height,
> +				rect->width, rect->height);
> +		return -EINVAL;
> +	}

No, that's not an error. Just use whatever you managed to configure.

> +	return 0;
> +}
> +
> +static int omap1_cam_try_fmt(struct soc_camera_device *icd,
> +			      struct v4l2_format *f)
> +{
> +	struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
> +	const struct soc_camera_format_xlate *xlate;
> +	struct device *dev = icd->dev.parent;
> +	struct v4l2_pix_format *pix = &f->fmt.pix;
> +	struct v4l2_mbus_framefmt mf, testmf;
> +	const struct soc_mbus_pixelfmt *fmt;
> +	int ret;
> +
> +	xlate = soc_camera_xlate_by_fourcc(icd, pix->pixelformat);
> +	if (!xlate) {
> +		dev_warn(dev, "%s: format %x not found\n", __func__,
> +				pix->pixelformat);
> +		return -EINVAL;
> +	}
> +
> +	fmt = xlate->host_fmt;
> +	ret = dma_align(&pix->width, &pix->height, fmt, true);
> +	if (ret < 0) {
> +		dev_err(dev, "%s: failed to align %ux%u %s with DMA\n",
> +				__func__, pix->width, pix->height, fmt->name);
> +		return ret;
> +	}
> +
> +	mf.width      = pix->width;
> +	mf.height     = pix->height;
> +	mf.field      = pix->field;
> +	mf.colorspace = pix->colorspace;
> +	mf.code	      = xlate->code;
> +
> +	/* limit to sensor capabilities */
> +	ret = v4l2_subdev_call(sd, video, try_mbus_fmt, &mf);
> +	if (ret < 0) {
> +		dev_err(dev, "%s: try_mbus_fmt() failed\n", __func__);
> +		return ret;
> +	}
> +
> +	pix->field	= mf.field;
> +	pix->colorspace	= mf.colorspace;
> +
> +	if (mf.width == pix->width && mf.height == pix->height &&
> +			mf.code == xlate->code)
> +		return 0;
> +
> +	dev_dbg(dev, "%s: geometry changed, recheck alignment\n", __func__);
> +	pix->width	  = mf.width;
> +	pix->height	  = mf.height;

This is what the sensor has returned, you put it back into the user frmat.

> +
> +	fmt = soc_mbus_get_fmtdesc(mf.code);
> +	ret = dma_align(&pix->width, &pix->height, fmt, false);

And you DMA-align those sizes.

> +	if (ret < 0) {
> +		dev_err(dev, "%s: failed to align %ux%u %s with DMA\n",
> +				__func__, pix->width, pix->height, fmt->name);
> +		return ret;
> +	}
> +	if (ret)
> +		return 0;
> +
> +	testmf.width	  = pix->width;
> +	testmf.height	  = pix->height;

And use them again for try_fmt

> +	testmf.field	  = mf.field;
> +	testmf.colorspace = mf.colorspace;
> +	testmf.code	  = mf.code;
> +
> +	ret = v4l2_subdev_call(sd, video, try_mbus_fmt, &testmf);
> +	if (ret < 0) {
> +		dev_err(dev, "%s: try_mbus_fmt() failed\n", __func__);
> +		return ret;
> +	}
> +
> +	if (testmf.code != mf.code || testmf.width != mf.width ||
> +			testmf.height != mf.height) {
> +		dev_err(dev, "%s: sensor format inconsistency, giving up\n",
> +				__func__);
> +		return -EINVAL;

As a general rule, try_fmt shouldn't fail... Only in very weird cases, 
really.

> +	}

And you verified, the sensor kept them.

> +	dev_notice(dev, "%s: "
> +		"sensor frame not DMA aligned, will try to crop from set_fmt()"

Hm? You did align them above? /me confused...

> +		"\n", __func__);
> +
> +	return 0;
> +}
> +
> +static void omap1_cam_init_videobuf(struct videobuf_queue *q,
> +				     struct soc_camera_device *icd)
> +{
> +	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
> +	struct omap1_cam_dev *pcdev = ici->priv;
> +
> +#ifndef CONFIG_VIDEO_OMAP1_SG
> +	videobuf_queue_dma_contig_init(q, &omap1_videobuf_ops, icd->dev.parent,
> +					&pcdev->lock,
> +					V4L2_BUF_TYPE_VIDEO_CAPTURE,
> +					V4L2_FIELD_NONE,
> +					sizeof(struct omap1_cam_buf),
> +					icd);
> +#else
> +	videobuf_queue_sg_init(q, &omap1_videobuf_ops, icd->dev.parent,
> +					&pcdev->lock,
> +					V4L2_BUF_TYPE_VIDEO_CAPTURE,
> +					V4L2_FIELD_NONE,
> +					sizeof(struct omap1_cam_buf),
> +					icd);
> +#endif
> +}
> +
> +static int omap1_cam_reqbufs(struct soc_camera_file *icf,
> +			      struct v4l2_requestbuffers *p)
> +{
> +	int i;
> +
> +	/*
> +	 * This is for locking debugging only. I removed spinlocks and now I
> +	 * check whether .prepare is ever called on a linked buffer, or whether
> +	 * a dma IRQ can occur for an in-work or unlinked buffer. Until now
> +	 * it hadn't triggered
> +	 */
> +	for (i = 0; i < p->count; i++) {
> +		struct omap1_cam_buf *buf = container_of(icf->vb_vidq.bufs[i],
> +						      struct omap1_cam_buf, vb);
> +		buf->inwork = 0;
> +		INIT_LIST_HEAD(&buf->vb.queue);
> +	}
> +
> +	return 0;
> +}
> +
> +static int omap1_cam_querycap(struct soc_camera_host *ici,
> +			       struct v4l2_capability *cap)
> +{
> +	/* cap->name is set by the friendly caller:-> */
> +	strlcpy(cap->card, "OMAP1 Camera", sizeof(cap->card));
> +	cap->version = VERSION_CODE;
> +	cap->capabilities = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
> +
> +	return 0;
> +}
> +
> +static int omap1_cam_set_bus_param(struct soc_camera_device *icd,
> +		__u32 pixfmt)
> +{
> +	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
> +	struct omap1_cam_dev *pcdev = ici->priv;
> +	struct device *dev = icd->dev.parent;
> +	const struct soc_camera_format_xlate *xlate;
> +	const struct soc_mbus_pixelfmt *fmt;
> +	unsigned long camera_flags, common_flags;
> +	unsigned int ctrlclock, mode;
> +	int ret;
> +
> +	camera_flags = icd->ops->query_bus_param(icd);
> +
> +	common_flags = soc_camera_bus_param_compatible(camera_flags,
> +			SOCAM_BUS_FLAGS);
> +	if (!common_flags)
> +		return -EINVAL;
> +
> +	/* Make choices, possibly based on platform configuration */
> +	if ((common_flags & SOCAM_PCLK_SAMPLE_RISING) &&
> +			(common_flags & SOCAM_PCLK_SAMPLE_FALLING)) {
> +		if (!pcdev->pdata ||
> +				pcdev->pdata->flags & OMAP1_CAMERA_LCLK_RISING)
> +			common_flags &= ~SOCAM_PCLK_SAMPLE_FALLING;
> +		else
> +			common_flags &= ~SOCAM_PCLK_SAMPLE_RISING;
> +	}
> +
> +	ret = icd->ops->set_bus_param(icd, common_flags);
> +	if (ret < 0)
> +		return ret;
> +
> +	ctrlclock = CAM_READ_CACHE(pcdev, CTRLCLOCK);
> +	if (ctrlclock & LCLK_EN)
> +		CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock & ~LCLK_EN);
> +
> +	if (common_flags & SOCAM_PCLK_SAMPLE_RISING) {
> +		dev_dbg(dev, "CTRLCLOCK_REG |= POLCLK\n");
> +		ctrlclock |= POLCLK;
> +	} else {
> +		dev_dbg(dev, "CTRLCLOCK_REG &= ~POLCLK\n");
> +		ctrlclock &= ~POLCLK;
> +	}
> +	CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock & ~LCLK_EN);
> +
> +	if (ctrlclock & LCLK_EN)
> +		CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock);
> +
> +	/* select bus endianess */
> +	xlate = soc_camera_xlate_by_fourcc(icd, pixfmt);
> +	fmt = xlate->host_fmt;
> +
> +	if (fmt->order == SOC_MBUS_ORDER_LE) {
> +		dev_dbg(dev, "MODE_REG &= ~ORDERCAMD\n");
> +		mode = CAM_READ(pcdev, MODE) & ~ORDERCAMD;
> +	} else {
> +		dev_dbg(dev, "MODE_REG |= ORDERCAMD\n");
> +		mode = CAM_READ(pcdev, MODE) | ORDERCAMD;
> +	}
> +	CAM_WRITE(pcdev, MODE, mode);
> +
> +	return 0;
> +}
> +
> +static unsigned int omap1_cam_poll(struct file *file, poll_table *pt)
> +{
> +	struct soc_camera_file *icf = file->private_data;
> +	struct omap1_cam_buf *buf;
> +
> +	buf = list_entry(icf->vb_vidq.stream.next, struct omap1_cam_buf,
> +			 vb.stream);
> +
> +	poll_wait(file, &buf->vb.done, pt);
> +
> +	if (buf->vb.state == VIDEOBUF_DONE ||
> +	    buf->vb.state == VIDEOBUF_ERROR)
> +		return POLLIN | POLLRDNORM;
> +
> +	return 0;
> +}
> +
> +static struct soc_camera_host_ops omap1_host_ops = {
> +	.owner		= THIS_MODULE,
> +	.add		= omap1_cam_add_device,
> +	.remove		= omap1_cam_remove_device,
> +	.get_formats	= omap1_cam_get_formats,
> +	.set_crop	= omap1_cam_set_crop,
> +	.set_fmt	= omap1_cam_set_fmt,
> +	.try_fmt	= omap1_cam_try_fmt,
> +	.init_videobuf	= omap1_cam_init_videobuf,
> +	.reqbufs	= omap1_cam_reqbufs,
> +	.querycap	= omap1_cam_querycap,
> +	.set_bus_param	= omap1_cam_set_bus_param,
> +	.poll		= omap1_cam_poll,
> +};
> +
> +static int __init omap1_cam_probe(struct platform_device *pdev)
> +{
> +	struct omap1_cam_dev *pcdev;
> +	struct resource *res;
> +	struct clk *clk;
> +	void __iomem *base;
> +	unsigned int irq;
> +	int err = 0;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	irq = platform_get_irq(pdev, 0);
> +	if (!res || (int)irq <= 0) {
> +		err = -ENODEV;
> +		goto exit;
> +	}
> +
> +	clk = clk_get(&pdev->dev, "armper_ck");
> +	if (IS_ERR(clk)) {
> +		err = PTR_ERR(clk);
> +		goto exit;
> +	}
> +
> +	pcdev = kzalloc(sizeof(*pcdev), GFP_KERNEL);
> +	if (!pcdev) {
> +		dev_err(&pdev->dev, "Could not allocate pcdev\n");
> +		err = -ENOMEM;
> +		goto exit_put_clk;
> +	}
> +
> +	pcdev->res = res;
> +	pcdev->clk = clk;
> +
> +	pcdev->pdata = pdev->dev.platform_data;
> +	pcdev->pflags = pcdev->pdata->flags;
> +
> +	if (pcdev->pdata)
> +		pcdev->camexclk = pcdev->pdata->camexclk_khz * 1000;
> +
> +	switch (pcdev->camexclk) {
> +	case CAM_EXCLK_6MHz:
> +	case CAM_EXCLK_8MHz:
> +	case CAM_EXCLK_9_6MHz:
> +	case CAM_EXCLK_12MHz:
> +	case CAM_EXCLK_24MHz:
> +		break;
> +	default:
> +		dev_warn(&pdev->dev,
> +				"Incorrect sensor clock frequency %ld kHz, "
> +				"should be one of 0, 6, 8, 9.6, 12 or 24 MHz, "
> +				"please correct your platform data\n",
> +				pcdev->pdata->camexclk_khz);
> +		pcdev->camexclk = 0;
> +	case 0:
> +		dev_info(&pdev->dev,
> +				"Not providing sensor clock\n");
> +	}
> +
> +	INIT_LIST_HEAD(&pcdev->capture);
> +	spin_lock_init(&pcdev->lock);
> +
> +	/*
> +	 * Request the region.
> +	 */
> +	if (!request_mem_region(res->start, resource_size(res), DRIVER_NAME)) {
> +		err = -EBUSY;
> +		goto exit_kfree;
> +	}
> +
> +	base = ioremap(res->start, resource_size(res));
> +	if (!base) {
> +		err = -ENOMEM;
> +		goto exit_release;
> +	}
> +	pcdev->irq = irq;
> +	pcdev->base = base;
> +
> +	/* apply reset to camera sensor if requested by platform data */
> +	if (pcdev->pflags & OMAP1_CAMERA_RST_HIGH)
> +		CAM_WRITE(pcdev, GPIO, 0x1);
> +	else if (pcdev->pflags & OMAP1_CAMERA_RST_LOW)
> +		CAM_WRITE(pcdev, GPIO, 0x0);

Why not use sensor_reset()?

> +
> +	err = omap_request_dma(OMAP_DMA_CAMERA_IF_RX, DRIVER_NAME,
> +			dma_isr, (void *)pcdev, &pcdev->dma_ch);
> +	if (err < 0) {
> +		dev_err(&pdev->dev, "Can't request DMA for OMAP1 Camera\n");
> +		err = -EBUSY;
> +		goto exit_iounmap;
> +	}
> +	dev_dbg(&pdev->dev, "got DMA channel %d\n", pcdev->dma_ch);
> +
> +	/* preconfigure DMA */
> +	omap_set_dma_src_params(pcdev->dma_ch, OMAP_DMA_PORT_TIPB,
> +			OMAP_DMA_AMODE_CONSTANT, res->start + REG_CAMDATA,
> +			0, 0);
> +	omap_set_dma_dest_burst_mode(pcdev->dma_ch, OMAP_DMA_DATA_BURST_4);
> +	/* setup DMA autoinitialization */
> +	omap_dma_link_lch(pcdev->dma_ch, pcdev->dma_ch);
> +
> +	CAM_WRITE(pcdev, MODE, THRESHOLD_LEVEL << THRESHOLD_SHIFT);
> +
> +	err = request_irq(pcdev->irq, cam_isr, 0, DRIVER_NAME, pcdev);
> +	if (err) {
> +		dev_err(&pdev->dev, "Camera interrupt register failed\n");
> +		goto exit_free_dma;
> +	}
> +
> +	pcdev->soc_host.drv_name	= DRIVER_NAME;
> +	pcdev->soc_host.ops		= &omap1_host_ops;
> +	pcdev->soc_host.priv		= pcdev;
> +	pcdev->soc_host.v4l2_dev.dev	= &pdev->dev;
> +	pcdev->soc_host.nr		= pdev->id;
> +
> +	err = soc_camera_host_register(&pcdev->soc_host);
> +	if (err)
> +		goto exit_free_irq;
> +
> +	dev_info(&pdev->dev, "OMAP1 Camera Interface driver loaded\n");
> +
> +	return 0;
> +
> +exit_free_irq:
> +	free_irq(pcdev->irq, pcdev);
> +exit_free_dma:
> +	omap_free_dma(pcdev->dma_ch);
> +exit_iounmap:
> +	iounmap(base);
> +exit_release:
> +	release_mem_region(res->start, resource_size(res));
> +exit_kfree:
> +	kfree(pcdev);
> +exit_put_clk:
> +	clk_put(clk);
> +exit:
> +	return err;
> +}
> +
> +static int __exit omap1_cam_remove(struct platform_device *pdev)
> +{
> +	struct soc_camera_host *soc_host = to_soc_camera_host(&pdev->dev);
> +	struct omap1_cam_dev *pcdev = container_of(soc_host,
> +					struct omap1_cam_dev, soc_host);
> +	struct resource *res;
> +
> +	soc_camera_host_unregister(soc_host);
> +
> +	free_irq(pcdev->irq, pcdev);
> +
> +	omap_free_dma(pcdev->dma_ch);

It is probably safer to first shut down the hardware, and only then 
unconfigure software. So, free_irq and free_dma should go first, I think.

> +
> +	iounmap(pcdev->base);
> +
> +	res = pcdev->res;
> +	release_mem_region(res->start, resource_size(res));
> +
> +	kfree(pcdev);
> +
> +	clk_put(pcdev->clk);
> +
> +	dev_info(&pdev->dev, "OMAP1 Camera Interface driver unloaded\n");
> +
> +	return 0;
> +}
> +
> +static struct platform_driver omap1_cam_driver = {
> +	.driver		= {
> +		.name	= DRIVER_NAME,
> +	},
> +	.probe		= omap1_cam_probe,
> +	.remove		= __exit_p(omap1_cam_remove),
> +};
> +
> +static int __init omap1_cam_init(void)
> +{
> +	return platform_driver_register(&omap1_cam_driver);
> +}
> +
> +static void __exit omap1_cam_exit(void)
> +{
> +	platform_driver_unregister(&omap1_cam_driver);
> +}
> +
> +module_init(omap1_cam_init);
> +module_exit(omap1_cam_exit);
> +
> +MODULE_DESCRIPTION("OMAP1 Camera Interface driver");
> +MODULE_AUTHOR("Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:" DRIVER_NAME);
> 

Other patch reviews to follow...

Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/

Re: [RFC] [PATCH 1/6] SoC Camera: add driver for OMAP1 camera interface

[Janusz Krzysztofik]

Friday 30 July 2010 13:07:42 Guennadi Liakhovetski napisał(a):
> Hi Janusz
>
> Thanks once more for the patches, from your patches it is obvious, that
> you've spent quite a bit of time on them and you have not just copy-pasted
> various bits and pieces from other drivers, just filling your hardware
> details, but you also actually understand a lot of what is actually going
> on in there. So, I think, fixing remaining mostly minor issues shouldn't
> be too difficult for you either.

Hi Guennadi,
Thanks for your review time.
I only tried to get the driver really working, not only looking good ;).

> On Sun, 18 Jul 2010, Janusz Krzysztofik wrote:
> > This is a V4L2 driver for TI OMAP1 SoC camera interface.
> >
> > Two versions of the driver are provided, using either videobuf-dma-contig
> > or videobuf-dma-sg. The former uses less processing power, but often
> > fails to allocate contignuous buffer memory. The latter is free of this
> > problem, but generates tens of DMA interrupts per frame.
>
> Hm, would it be difficult to first try contig, and if it fails - fall back
> to sg?

Hmm, let me think about it.

> In its present state buffer management in your driver is pretty difficult
> to follow. At the VERY least you have to extensively document your buffer
> manipulations. Better yet clean it up. AFAIU, your "ready" pointer is
> pretty much unused in the contiguous case. Or you can easily get rid of
> it. 

I was sure the "ready" pointer was essential for both paths. However, things 
tend to change as more and more optimizations / cleanups are applied, so I 
have to verify it again.

> So, I think, a very welcome improvement to the driver would be a 
> cleaner separation between the two cases. Don't try that much to reuse the
> code as much as possible. Would be much better to have clean separation
> between the two implementations - whether dynamically switchable at
> runtime or at config time - would be best to separate the two
> implementations to the point, where each of them becomes understandable
> and maintainable.

You are right. My approach was probably more adequate at development time, 
when I was trying to aviod error-prone code duplication. As soon as both 
paths get stable, they can be split for better readability. I'll take care of 
this.

> So, I will do a pretty formal review this time and wait for v2. And in v2
> I'd like to at the very least see detailed buffer-management
> documentation, or - better yet - a rework with a clean separation.

OK.

...
> > --- linux-2.6.35-rc3.orig/include/media/omap1_camera.h	1970-01-01
> > 01:00:00.000000000 +0100
> > +++ linux-2.6.35-rc3/include/media/omap1_camera.h	2010-07-18
> > 01:31:57.000000000 +0200
> > @@ -0,0 +1,16 @@ 
>
> A copyright / licence header here, please

OK.

> > +#ifndef __MEDIA_OMAP1_CAMERA_H_
> > +#define __MEDIA_OMAP1_CAMERA_H_
> > +
> > +#define OMAP1_CAMERA_IOSIZE		0x1c
> > +
> > +struct omap1_cam_platform_data {
> > +	unsigned long camexclk_khz;
> > +	unsigned long lclk_khz_max;
> > +	unsigned long flags;
> > +};
> > +
> > +#define OMAP1_CAMERA_LCLK_RISING	BIT(0)
> > +#define OMAP1_CAMERA_RST_LOW		BIT(1)
> > +#define OMAP1_CAMERA_RST_HIGH		BIT(2)
>
> Then you need to #include <linux/bitops.h>

OK.
Since I always tend to optimise out redundant includes of header files that 
are otherwise included indirectly, please verify if there are more of them 
that you would prefere included explicitly.

> > +
> > +#endif /* __MEDIA_OMAP1_CAMERA_H_ */
> > --- linux-2.6.35-rc3.orig/drivers/media/video/Kconfig	2010-06-26
> > 15:55:29.000000000 +0200 +++
> > linux-2.6.35-rc3/drivers/media/video/Kconfig	2010-07-02
> > 04:12:02.000000000 +0200 @@ -962,6 +962,20 @@ config VIDEO_SH_MOBILE_CEU
> >  	---help---
> >  	  This is a v4l2 driver for the SuperH Mobile CEU Interface
> >
> > +config VIDEO_OMAP1
> > +	tristate "OMAP1 Camera Interface driver"
> > +	depends on VIDEO_DEV && ARCH_OMAP1 && SOC_CAMERA
> > +	select VIDEOBUF_DMA_CONTIG if !VIDEO_OMAP1_SG
> > +	---help---
> > +	  This is a v4l2 driver for the TI OMAP1 camera interface
> > +
> > +if VIDEO_OMAP1
>
> Don't think you need this "if," the "depends on" below should suffice.

OK.
My intention was to get it indented, and now I see it works like this even if 
not enclosed with if-endif.
Will drop the if-endif if the compile time SG option survives.

> > +config VIDEO_OMAP1_SG
> > +	bool "Scatter-gather mode"
> > +	depends on VIDEO_OMAP1 && EXPERIMENTAL
> > +	select VIDEOBUF_DMA_SG
> > +endif
> > +

...
> > +#ifndef CONFIG_VIDEO_OMAP1_SG
> > +#include <media/videobuf-dma-contig.h>
> > +#else
> > +#include <media/videobuf-dma-sg.h>
> > +#endif
>
> I think, you can just include both headers.

OK.

...
> > +#define CAM_EXCLK_6MHz		 6000000
> > +#define CAM_EXCLK_8MHz		 8000000
> > +#define CAM_EXCLK_9_6MHz	 9600000
> > +#define CAM_EXCLK_12MHz		12000000
> > +#define CAM_EXCLK_24MHz		24000000
>
> Why do you need this? Your platform specifies the EXCLK frequency directly
> in kHz, then you multiplly it by 1000 to get pcdev->camexclk in Hz, then
> you compare it to these macros. Don't think you need them - just use
> numbers directly.

OK.
My only reason for defines here was thees numbers being used more than once.

...
> > +/*
> > + * Structures
> > + */
> > +
> > +/* buffer for one video frame */
> > +struct omap1_cam_buf {
> > +	struct videobuf_buffer		vb;
> > +	enum v4l2_mbus_pixelcode	code;
> > +	int				inwork;
> > +#ifdef CONFIG_VIDEO_OMAP1_SG
> > +	struct scatterlist		*sgbuf;
> > +	int				sgcount;
> > +	int				bytes_left;
> > +	enum videobuf_state		result;
> > +#endif
> > +};
> > +
> > +struct omap1_cam_dev {
> > +	struct soc_camera_host		soc_host;
> > +	struct soc_camera_device	*icd;
> > +	struct clk			*clk;
> > +
> > +	unsigned int			irq;
> > +	void __iomem			*base;
> > +
> > +	int				dma_ch;
> > +
> > +	struct omap1_cam_platform_data	*pdata;
> > +	struct resource			*res;
> > +	unsigned long			pflags;
> > +	unsigned long			camexclk;
> > +
> > +	struct list_head		capture;
> > +
> > +	spinlock_t			lock;
> > +
> > +	/* Pointers to DMA buffers */
> > +	struct omap1_cam_buf		*active;
> > +	struct omap1_cam_buf		*ready;
>
> Well, I must confess, as it stands, you managed to confuse me with your
> "active" and "ready" buffer management. Is the reason for these two
> pointers some hardware feature? Maybe that while one buffer is being
> filled by DMA you can already configure the DMA engine with the next one?

Exactly. Both dma-contig and dma-sg paths relay on this hardware feature, 
making use of this "ready" pointing to a not yet active but already 
dma-preprogrammed videobuf.

> > +
> > +	u32			reg_cache[OMAP1_CAMERA_IOSIZE / sizeof(u32)];
>
> Don't think you'd lose much performance without cache, for that the code
> would become less error-prone.

The reason is my bad experience with my hardware audio interface. For my 
rationale regarding OMAP McBSP register caching, please look at this commit:
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=96fbd74551e9cae8fd5e9cb62a0a19336a3064fa
or the foregoing discussions (links both to my initial and final submitions):
http://thread.gmane.org/gmane.linux.alsa.devel/65675
http://thread.gmane.org/gmane.linux.ports.arm.omap/29708

However, I haven't noticed any similiar flaws in camera interface yet, so if 
you think that caching would not be helpful in any possible future (context 
save/restore) enhancements here, then I can drop it.

> > +};
> > +
> > +
> > +void cam_write(struct omap1_cam_dev *pcdev, u16 reg, u32 val)
>
> static

Sure.

> > +{
> > +	pcdev->reg_cache[reg / sizeof(u32)] = val;
> > +	__raw_writel(val, pcdev->base + reg);
> > +}
> > +
> > +int cam_read(struct omap1_cam_dev *pcdev, u16 reg, bool from_cache)
>
> static u32

OK.

> > +{
> > +	return !from_cache ? __raw_readl(pcdev->base + reg) :
> > +			pcdev->reg_cache[reg / sizeof(u32)];
>
> hmmm.... it's never simple with caches;) Some registers (e.g., CTRLCLOCK)
> you read both from the cache and from the hardware directly. 

I read the CTRLCLOCK from the hardware in omap1_cam_add_device() for one 
reason: the cache is (can be) not initialized (written with the register 
copy) yet, and there are reserved bits that I'm trying to keep untouched.

The read from the hardware in omap1_cam_remove_device() is not intentional and 
should be replaced with cache read if we don't drop register caching.

Other than that, reads from cache are used throughout other functions, I 
believe.

> Don't you have to update the cache on a direct read?

If I do it unconditionally, I'd loose the read error prevention function of 
register caching idea.

> > +}
> > +
> > +#define CAM_READ(pcdev, reg) \
> > +		cam_read(pcdev, REG_##reg, 0)
>
> last parameter is a bool, so, use "false"

Right.

> > +#define CAM_WRITE(pcdev, reg, val) \
> > +		cam_write(pcdev, REG_##reg, val)
> > +#define CAM_READ_CACHE(pcdev, reg) \
> > +		cam_read(pcdev, REG_##reg, 1)
>
> "true"

Of course.

...
> > +static void start_capture(struct omap1_cam_dev *pcdev)
> > +{
> > +	struct omap1_cam_buf *buf = pcdev->active;
> > +	unsigned long ctrlclock = CAM_READ_CACHE(pcdev, CTRLCLOCK);
> > +	unsigned long mode = CAM_READ_CACHE(pcdev, MODE);
>
> I would make all variables, that are used specifically for various
> registers u32.

OK.

> > +
> > +	if (WARN_ON(!buf))
> > +		return;
> > +
> > +#ifndef CONFIG_VIDEO_OMAP1_SG
> > +	/* don't enable end of frame interrupts before capture autostart */
> > +	mode &= ~EN_V_DOWN;
> > +#endif
> > +	if (WARN_ON(mode & RAZ_FIFO))
> > +		/*  clean up possibly insane reset condition */
> > +		CAM_WRITE(pcdev, MODE, mode &= ~RAZ_FIFO);
>
> It is usually better to avoid assigning variables inside other constructs,
> please split into two lines. 

OK, I'll review and rearrange all similiar constructs.

> Besides, in omap1_cam_probe() you initialise 
> MODE to "THRESHOLD_LEVEL << THRESHOLD_SHIFT," i.e., RAZ_FIFO is cleared.
> So, don't think you need that test at all.

Right. What you think is better, drop it, or replace with BUG_ON(mode & 
RAZ_FIFO)?

...
> > +static void suspend_capture(struct omap1_cam_dev *pcdev)
> > +{
> > +	unsigned long ctrlclock = CAM_READ_CACHE(pcdev, CTRLCLOCK);
>
> u32

Yes.

> > +
> > +	CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock & ~LCLK_EN);
> > +	omap_stop_dma(pcdev->dma_ch);
> > +}
> > +
> > +static void disable_capture(struct omap1_cam_dev *pcdev)
> > +{
> > +	unsigned long mode = CAM_READ_CACHE(pcdev, MODE);
>
> u32 (etc.)

Mmh.

...
> > +	dev_dbg(icd->dev.parent, "%s: capture not active, setup FIFO, start
> > DMA"
> > +			"\n", __func__); 
>
> No need to split "\n" to a new line, don't worry about > 80 characters...

OK, for this one and all similiar cases.

...
> > +static void videobuf_done(struct omap1_cam_dev *pcdev,
> > +		enum videobuf_state result)
> > +{
> > +	struct omap1_cam_buf *buf = pcdev->active;
> > +	struct videobuf_buffer *vb;
> > +	struct device *dev = pcdev->icd->dev.parent;
> > +
> > +	if (WARN_ON(!buf)) {
> > +		suspend_capture(pcdev);
> > +		disable_capture(pcdev);
> > +		return;
> > +	}
> > +
> > +	if (result == VIDEOBUF_ERROR)
> > +		suspend_capture(pcdev);
> > +
> > +	vb = &buf->vb;
> > +	if (waitqueue_active(&vb->done)) {
>
> I'm not sure this is a good idea. Why are you reusing the buffer, if noone
> is waiting for it _now_? It can well be, that the task is doing something
> else atm. Like processing the previous frame. Or it has been preempted by
> another process, before it called poll() or select() on your device?

I've introduced this way of videobuf handling after learning, form the 
Documentation/video4linux/videobuf, what the first step of filling a buffer 
should be:

"- Obtain the next available buffer and make sure that somebody is actually
   waiting for it."

Since I had no idea how I could implement it, I decided to do it a bit 
differently: start filling a buffer unconditionally, then drop its contents 
if not awaited by any user when done.

> > +		if (!pcdev->ready && result != VIDEOBUF_ERROR)
> > +			suspend_capture(pcdev);
> > +		vb->state = result;
> > +		do_gettimeofday(&vb->ts);
> > +		vb->field_count++;
>
> I don't think you're supposed to increment field_count if you've got a
> VIDEOBUF_ERROR.

OK, I'll correct it.

> > +		wake_up(&vb->done);
> > +
> > +		pcdev->active = buf = pcdev->ready;

Self comment: this construct occured to not satisfy "checkpatch --strict". I'm 
going to correct all similiar cases.

> > +		pcdev->ready = NULL;
> > +
> > +		if (!buf) {
> > +			result = VIDEOBUF_ERROR;
> > +			prepare_next_vb(pcdev);
> > +
> > +			pcdev->active = buf = pcdev->ready;
> > +			pcdev->ready = NULL;
> > +		}
> > +	} else if (pcdev->ready) {
> > +		dev_dbg(dev, "%s: nobody waiting on videobuf, swap with next\n",
> > +				__func__);
>
> Not sure this is a wise decision... If there are more buffers in the
> queue, they stay there waiting. Best remove this waitqueue_active() check
> entirely, just complete buffers and wake up the user regardless. If no
> more buffers - go to sleep.

If you think I don't have to follow the above mentioned requirement for not 
servicing a buffer unless someone is waiting for it, then yes, I'll drop 
these overcomplicated bits. Please confirm.

> > +		pcdev->active = pcdev->ready;
> > +#ifdef CONFIG_VIDEO_OMAP1_SG
> > +		buf->sgbuf = NULL;
> > +#endif
> > +		pcdev->ready = buf;
> > +
> > +		buf = pcdev->active;
> > +	} else {
> > +#ifndef CONFIG_VIDEO_OMAP1_SG
> > +		dev_dbg(dev, "%s: nobody waiting on videobuf, reuse it\n",
> > +				__func__);
> > +#else
> > +		if (result != VIDEOBUF_ERROR) {
> > +			suspend_capture(pcdev);
> > +			result = VIDEOBUF_ERROR;
> > +		}
> > +		prepare_next_vb(pcdev);
> > +#endif
> > +	}
> > +
> > +	if (!buf) {
> > +		dev_dbg(dev, "%s: no more videobufs, stop capture\n", __func__);
> > +		disable_capture(pcdev);
> > +		return;
> > +	}
> > +
> > +#ifdef CONFIG_VIDEO_OMAP1_SG
> > +	if (result == VIDEOBUF_ERROR)
> > +		buf->sgbuf = NULL;
> > +
> > +	try_next_sgbuf(pcdev->dma_ch, buf);
> > +#endif
> > +
> > +	if (result == VIDEOBUF_ERROR) {
> > +		dev_dbg(dev, "%s: videobuf error; reset FIFO, restart DMA\n",
> > +				__func__);
> > +		start_capture(pcdev);
> > +	}
>
> This all doesn't look quite right, but I'll wait for documentation, before
> commenting.

In short: in case of any error, I assume not being able to ensure that next 
frame still starts at next videobuf start, that's why I restart capture.

start_capture() doesn't actually start anything, only initializes it. After 
FIFO reset, the hardware stays idle until first frame start (as indicated by 
both VSYNC and HSYNC active), then starts filling its FIFO on LCLK edges 
selected with POLCLK and requesting DMA automatically every THRESHOLD_LEVEL 
words.

> > +
> > +	prepare_next_vb(pcdev);
> > +}
> > +
> > +static void dma_isr(int channel, unsigned short status, void *data)
> > +{
> > +	struct omap1_cam_dev *pcdev = data;
> > +	struct omap1_cam_buf *buf = pcdev->active;
> > +	enum videobuf_state result;
> > +	unsigned long flags;
> > +
> > +	spin_lock_irqsave(&pcdev->lock, flags);
> > +
> > +	if (WARN_ON(!buf)) {
> > +		suspend_capture(pcdev);
> > +		disable_capture(pcdev);
> > +		goto out;
> > +	}
> > +
> > +#ifndef CONFIG_VIDEO_OMAP1_SG
> > +	/* videobuf complete, disable end of frame interrupt for this frame */
> > +	CAM_WRITE(pcdev, MODE, CAM_READ_CACHE(pcdev, MODE) & ~EN_V_DOWN);
> > +	result = VIDEOBUF_DONE;
> > +#else
> > +	if (buf->sgbuf) {
> > +		/* current sglist not complete yet */
> > +		try_next_sgbuf(pcdev->dma_ch, buf);
> > +		if (buf->sgbuf)
> > +			goto out;
> > +
> > +		if (buf->result != VIDEOBUF_ERROR) {
> > +			buf = prepare_next_vb(pcdev);
> > +			if (!buf)
> > +				goto out;
> > +
> > +			try_next_sgbuf(pcdev->dma_ch, buf);
> > +			goto out;
> > +		}
> > +	}
> > +	/* end of videobuf */
> > +	result = buf->result;
> > +#endif
> > +	videobuf_done(pcdev, result);
> > +out:
> > +	spin_unlock_irqrestore(&pcdev->lock, flags);
> > +}
> > +
> > +static irqreturn_t cam_isr(int irq, void *data)
> > +{
> > +	struct omap1_cam_dev *pcdev = data;
> > +	struct device *dev = pcdev->icd->dev.parent;
> > +	struct omap1_cam_buf *buf = pcdev->active;
> > +	unsigned long it_status;
> > +	unsigned long flags;
> > +
> > +	it_status = CAM_READ(pcdev, IT_STATUS);
> > +	if (!it_status)
> > +		return IRQ_NONE;
> > +
> > +	spin_lock_irqsave(&pcdev->lock, flags);
> > +
> > +	if (WARN_ON(!buf)) {
> > +		suspend_capture(pcdev);
> > +		disable_capture(pcdev);
> > +		goto out;
> > +	}
> > +
> > +	if (unlikely(it_status & FIFO_FULL)) {
> > +		dev_warn(dev, "%s: FIFO overflow\n", __func__);
> > +
> > +	} else if (it_status & V_DOWN) {
> > +#ifdef CONFIG_VIDEO_OMAP1_SG
> > +		/*
> > +		 * if exactly 2 sgbufs of the next sglist has be used,
> > +		 * then we are in sync
> > +		 */
>
> You mean the hardware is supposed to interrupt you after 2 buffers?

No.
This interrupt occures on every frame end. By this moment, DMA, that is set up 
to restart automatically on every DMA block end, should already be waiting 
for first data to put into the first sgbuf area of the next sglist, pointed 
out by the DMA working registers, and the second sgbuf from this list should 
already be entered by the dma_isr() into the DMA programming registers, ready 
for DMA auto restart on current sgbuf (DMA block) end.

> > +		if (buf && buf->sgcount == 2)
> > +			goto out;
> > +#endif
> > +		dev_notice(dev, "%s: unexpected end of video frame\n",
> > +				__func__);
> > +
> > +#ifndef CONFIG_VIDEO_OMAP1_SG
> > +	} else if (it_status & V_UP) {
> > +		unsigned long mode = CAM_READ_CACHE(pcdev, MODE);
> > +
> > +		if (!(mode & EN_V_DOWN)) {
> > +			/* enable end of frame interrupt for current videobuf */
> > +			CAM_WRITE(pcdev, MODE, mode | EN_V_DOWN);
> > +		}
> > +		goto out;
> > +#endif
> > +
> > +	} else {
> > +		dev_warn(pcdev->soc_host.v4l2_dev.dev, "%s: "
> > +				"unhandled camera interrupt, status == 0x%lx\n",
> > +				__func__, it_status);
> > +		goto out;
> > +	}
> > +
> > +	videobuf_done(pcdev, VIDEOBUF_ERROR);
> > +out:
> > +	spin_unlock_irqrestore(&pcdev->lock, flags);
> > +	return IRQ_HANDLED;
> > +}

...
> > +static int omap1_cam_add_device(struct soc_camera_device *icd)
> > +{
> > +	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
> > +	struct omap1_cam_dev *pcdev = ici->priv;
> > +	unsigned int ctrlclock;
>
> u32

Sure.

> > +	int ret = 0;
> > +
> > +	if (pcdev->icd) {
> > +		ret = -EBUSY;
> > +		goto ebusy;
> > +	}
> > +
> > +	clk_enable(pcdev->clk);
> > +
> > +	/* setup sensor clock */
> > +	ctrlclock = CAM_READ(pcdev, CTRLCLOCK);
> > +	ctrlclock &= ~(CAMEXCLK_EN | MCLK_EN | DPLL_EN);
> > +	CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock);
> > +
> > +	ctrlclock &= ~FOSCMOD_MASK;
> > +	switch (pcdev->camexclk) {
> > +	case CAM_EXCLK_6MHz:
>
> just use constants for these

You mean numbers (6000000 in this case) instead of predifined symbols, don't 
you?

> > +		ctrlclock |= CAMEXCLK_EN | FOSCMOD_6MHz;
> > +		break;
> > +	case CAM_EXCLK_8MHz:
> > +		ctrlclock |= CAMEXCLK_EN | FOSCMOD_8MHz | DPLL_EN;
> > +		break;
> > +	case CAM_EXCLK_9_6MHz:
> > +		ctrlclock |= CAMEXCLK_EN | FOSCMOD_9_6MHz | DPLL_EN;
> > +		break;
> > +	case CAM_EXCLK_12MHz:
> > +		ctrlclock |= CAMEXCLK_EN | FOSCMOD_12MHz;
> > +		break;
> > +	case CAM_EXCLK_24MHz:
> > +		ctrlclock |= CAMEXCLK_EN | FOSCMOD_24MHz | DPLL_EN;
> > +	default:
>
> This is the case of "Not providing sensor clock," do you still have to
> enable the clock at all below (MCLK_EN)?

I'm not absolutely sure, but I think I had already tried without it and it 
looked like FIFO didn't work. Will recheck.

> > +		break;
> > +	}
> > +	CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock & ~DPLL_EN);
> > +
> > +	/* enable clock */
> > +	ctrlclock |= MCLK_EN;
> > +	CAM_WRITE(pcdev, CTRLCLOCK, ctrlclock);
> > +
> > +	sensor_reset(pcdev, 0);
>
> use "false" for the second parameter

OK.

...
> > +/* Duplicate standard formats based on host capability of byte swapping
> > */
> > +static const struct soc_mbus_pixelfmt omap1_cam_formats[] = { 
> > +	[V4L2_MBUS_FMT_YUYV8_2X8_BE] = {
>
> You'll have to adjust these to the new names. Basically, for all YUYV8 and
> YVYU8 codes, "_LE" just gets dropped, and for "_BE" you swap
> chrominance-luminance pairs, i.e., UYVY8_2X8 instead of YUYV8_2X8_BE and
> VYUY8_2X8 instead of YVYU8_2X8_BE.

OK.

...
> > +static int is_dma_aligned(s32 bytes_per_line, unsigned int height)
>
> make it a bool

OK.

> > +{
> > +	int size = bytes_per_line * height;
> > +
> > +	return IS_ALIGNED(bytes_per_line, DMA_ELEMENT_SIZE) &&
> > +			IS_ALIGNED(size, DMA_FRAME_SIZE * DMA_ELEMENT_SIZE);
> > +}
> > +
> > +static int dma_align(int *width, int *height,
> > +		const struct soc_mbus_pixelfmt *fmt, bool enlarge)
> > +{
> > +	s32 bytes_per_line = soc_mbus_bytes_per_line(*width, fmt);
> > +
> > +	if (bytes_per_line < 0)
> > +		return bytes_per_line;
> > +
> > +	if (!is_dma_aligned(bytes_per_line, *height)) {
> > +		unsigned int pxalign = __fls(bytes_per_line / *width);
> > +		unsigned int salign  =
> > +				DMA_FRAME_SHIFT + DMA_ELEMENT_SHIFT - pxalign;
> > +		unsigned int incr    = enlarge << salign;
> > +
> > +		v4l_bound_align_image(width, DMA_ELEMENT_SIZE >> pxalign,
> > +				*width + incr, DMA_ELEMENT_SHIFT - pxalign,
>
> The above means, that lines must consist of an integer number of DMA
> elements, right? Is this really necessary?

Perhaps not really :). I'll recheck and remove the constraint if not.

> > +				height, 1, *height + incr, 0, salign);
> > +		return 0;
> > +	}
> > +	return 1;
> > +}

...
> > +		dev_dbg(dev, "%s: g_crop() missing, trying cropcap() instead"
> > +				"\n", __func__);
>
> Put "\n" back in the string

OK.

...
> > +	*rect  = crop.c;
>
> superfluous space

Mhm.

...
> > +		dev_dbg(dev, "%s: g_mbus_fmt() missing, trying g_crop() instead"
> > +				"\n", __func__);
>
> Put "\n" back in the string

Yes.

> > +		ret = get_crop(icd, &c);
> > +		if (ret < 0)
> > +			return ret;
> > +		/* REVISIT:
> > +		 * Should cropcap() obtained defrect reflect last s_crop()?
> > +		 * Can we use it here for s_crop() result verification?
> > +		 */
>
> multiline comment style

Could be dropped completely if you know the answer and share it with me :).

> > +		if (ret) {
> > +			*rect = c;	/* use g_crop() result */
> > +		} else {
> > +			dev_warn(dev, "%s: current geometry not available\n",
> > +					__func__);
> > +			return 0;
> > +		}
> > +	} else if (ret < 0) {
> > +		return ret;
> > +	} else if (mf.code != code) {
> > +		return -EINVAL;
> > +	} else {
> > +		rect->width  = mf.width;
> > +		rect->height = mf.height;
> > +	}
> > +	return 1;
> > +}
> > +
> > +#define subdev_call_with_sense(ret, function, args...) \
> > +{ \
> > +	struct soc_camera_sense sense = { \
> > +		.master_clock		= pcdev->camexclk, \
> > +		.pixel_clock_max	= 0, \
> > +	}; \
> > +\
> > +	if (pcdev->pdata) \
> > +		sense.pixel_clock_max = pcdev->pdata->lclk_khz_max * 1000; \
> > +	icd->sense = &sense; \
> > +	*(ret) = v4l2_subdev_call(sd, video, function, ##args); \
> > +	icd->sense = NULL; \
> > +\
> > +	if (sense.flags & SOCAM_SENSE_PCLK_CHANGED) { \
> > +		if (sense.pixel_clock > sense.pixel_clock_max) { \
> > +			dev_err(dev, "%s: " \
> > +				"pixel clock %lu set by the camera too high!" \
> > +				"\n", __func__, sense.pixel_clock); \
>
> "\n" back, please

Sure.

> > +			return -EIO; \
> > +		} \
> > +	} \
> > +}
>
> Ok, I'd prefer to follow some good-style rules here too. (1) please align
> your backslashes with TABs. (2) please, don't use implicitly passed
> variables, in this case "sd," "pcdev," "dev," and "icd." (3) since this is
> a macro, you don't need to pass ret as a pointer. (4) don't "return" from
> a macro - in your case it's enough to "ret = -EIO." Personally, I wouldn't
> worry about adding 4 more parameters to the macro. I would also remove
> "ret" from parameters and "return" it from the macro per
>
> #define subdev_call_with_sense(pcdev, dev, icd, sd, function, args...)	\
> ({									\
> 	int __ret;							\
> 	...								\
> 	__ret = v4l2_subdev_call(sd, video, function, ##args);		\
> 	...								\
> 			__ret = -EINVAL;				\
> 	...								\
> 	__ret;								\
> })

Thanks! :)

> > +
> > +static int omap1_cam_set_crop(struct soc_camera_device *icd,
> > +			       struct v4l2_crop *crop)
> > +{
> > +	struct v4l2_rect *rect = &crop->c;
> > +	struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
> > +	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
> > +	struct omap1_cam_dev *pcdev = ici->priv;
> > +	struct device *dev = icd->dev.parent;
> > +	s32 bytes_per_line;
> > +	int ret;
> > +
> > +	ret = dma_align(&rect->width, &rect->height,
> > icd->current_fmt->host_fmt,
> > +			false); 
> > +	if (ret < 0) {
> > +		dev_err(dev, "%s: failed to align %ux%u %s with DMA\n",
> > +				__func__, rect->width, rect->height,
> > +				icd->current_fmt->host_fmt->name);
> > +		return ret;
> > +	}
> > +
> > +	subdev_call_with_sense(&ret, s_crop, crop);
> > +	if (ret < 0) {
> > +		dev_warn(dev, "%s: failed to crop to %ux%u@%u:%u\n", __func__,
> > +			 rect->width, rect->height, rect->left, rect->top);
> > +		return ret;
> > +	}
> > +
> > +	ret = get_geometry(icd, rect, icd->current_fmt->code);
> > +	if (ret < 0) {
> > +		dev_err(dev, "%s: get_geometry() failed\n", __func__);
> > +		return ret;
> > +	}
> > +	if (!ret) {
> > +		dev_warn(dev, "%s: unable to verify s_crop() results\n",
> > +				__func__);
> > +	}
>
> Superfluous braces

Yes.

> > +
> > +	bytes_per_line = soc_mbus_bytes_per_line(rect->width,
> > +			icd->current_fmt->host_fmt);
> > +	if (bytes_per_line < 0) {
> > +		dev_err(dev, "%s: soc_mbus_bytes_per_line() failed\n",
> > +				__func__);
> > +		return bytes_per_line;
> > +	}
> > +
> > +	ret = is_dma_aligned(bytes_per_line, rect->height);
> > +	if (ret < 0) {
>
> Doesn't look like this is possible.

It was once :/. I'll correct it.

> > +		dev_err(dev, "%s: is_dma_aligned() failed\n", __func__);
> > +		return ret;
> > +	}
> > +	if (!ret) {
> > +		dev_err(dev, "%s: resulting geometry %dx%d not DMA aligned\n",
> > +				__func__, rect->width, rect->height);
> > +		return -EINVAL;
> > +	}
> > +
> > +	icd->user_width	 = rect->width;
> > +	icd->user_height = rect->height;
>
> No, this is wrong. user_width and user_height are _user_ sizes, i.e., a
> result sensor cropping and scaling and host cropping and scaling. Whereas
> set_crop sets sensor input rectangle.

I'm not sure if I understand what you mean. Should I drop these assignments? 
Or correct them? If yes, how they should be calculated?

In Documentation/video4linux/soc-camera.txt, you say:
"The core updates these fields upon successful completion of a .s_fmt() call, 
but if these fields change elsewhere, e.g., during .s_crop() processing, the 
host driver is responsible for updating them."

I thought this is the case we're dealing with here.

> > +
> > +	return ret;
> > +}
> > +
> > +static int omap1_cam_set_fmt(struct soc_camera_device *icd,
> > +			      struct v4l2_format *f)
> > +{
> > +	struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
> > +	const struct soc_camera_format_xlate *xlate;
> > +	struct device *dev = icd->dev.parent;
> > +	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
> > +	struct omap1_cam_dev *pcdev = ici->priv;
> > +	struct v4l2_pix_format *pix = &f->fmt.pix;
> > +	struct v4l2_mbus_framefmt mf;
> > +	struct v4l2_crop crop;
> > +	struct v4l2_rect *rect = &crop.c;
> > +	int bytes_per_line;
> > +	int ret;
> > +
> > +	xlate = soc_camera_xlate_by_fourcc(icd, pix->pixelformat);
> > +	if (!xlate) {
> > +		dev_warn(dev, "%s: format %x not found\n", __func__,
> > +				pix->pixelformat);
> > +		return -EINVAL;
> > +	}
> > +
> > +	bytes_per_line = soc_mbus_bytes_per_line(pix->width, xlate->host_fmt);
> > +	if (bytes_per_line < 0) {
> > +		dev_err(dev, "%s: soc_mbus_bytes_per_line() failed\n",
> > +				__func__);
> > +		return bytes_per_line;
> > +	}
> > +	if (pix->bytesperline && pix->bytesperline != bytes_per_line) {
> > +		dev_err(dev, "%s: bytes per line mismatch\n", __func__);
> > +		return -EINVAL;
> > +	}
> > +	ret = is_dma_aligned(bytes_per_line, pix->height);
> > +	if (ret < 0) {
>
> ditto - that's just a bool.

Sure.

> > +		dev_err(dev, "%s: is_dma_aligned() failed\n", __func__);
> > +		return ret;
> > +	}
> > +	if (!ret) {
> > +		dev_err(dev, "%s: image size %dx%d not DMA aligned\n",
> > +				__func__, pix->width, pix->height);
> > +		return -EINVAL;
> > +	}
> > +
> > +	mf.width	= pix->width;
> > +	mf.height	= pix->height;
> > +	mf.field	= pix->field;
> > +	mf.colorspace	= pix->colorspace;
> > +	mf.code		= xlate->code;
> > +
> > +	subdev_call_with_sense(&ret, s_mbus_fmt, &mf);
> > +	if (ret < 0) {
> > +		dev_err(dev, "%s: failed to set format\n", __func__);
> > +		return ret;
> > +	}
> > +
> > +	if (mf.code != xlate->code) {
> > +		dev_err(dev, "%s: unexpected pixel code change\n", __func__);
> > +		return -EINVAL;
> > +	}
> > +	icd->current_fmt = xlate;
> > +
> > +	pix->field	= mf.field;
> > +	pix->colorspace	= mf.colorspace;
> > +
> > +	if (mf.width == pix->width && mf.height == pix->height)
> > +		return 0;
> > +
> > +	dev_notice(dev, "%s: sensor geometry differs, trying to crop to %dx%d"
> > +			"\n", __func__, pix->width, pix->height);
>
> No, you shouldn't do this. It is normal, when S_FMT sets a format
> different from what the user has requested. Just leave it as is, only 
> adjust if you cannot handle it or fail. 

With my, maybe weird, try_fmt() implementation, I think I can be sure here 
that the geometry is not DMA aligned, unless a user can request a different 
geometry than she obtained from try_fmt(), that I assumed should not happen. 
Please see below for more exhausitve explanation.

> > +	crop.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
> > +	ret = get_crop(icd, rect);
> > +	if (ret < 0) {
> > +		dev_err(dev, "%s: get_crop() failed\n", __func__);
> > +		return ret;
> > +	}
> > +
> > +	rect->width  = pix->width;
> > +	rect->height = pix->height;
> > +
> > +	subdev_call_with_sense(&ret, s_crop, &crop);
> > +	if (ret < 0) {
> > +		dev_warn(dev, "%s: failed to crop to %ux%u@%u:%u\n", __func__,
> > +			 rect->width, rect->height, rect->left, rect->top);
> > +		return ret;
> > +	}
> > +
> > +	ret = get_geometry(icd, rect, xlate->code);
> > +	if (ret < 0) {
> > +		dev_err(dev, "%s: get_geometry() failed\n", __func__);
> > +		return ret;
> > +	}
> > +
> > +	if (!ret) {
> > +		dev_warn(dev, "%s: s_crop() results not verified\n", __func__);
> > +		return 0;
> > +	}
> > +
> > +	if (pix->width != rect->width || pix->height != rect->height) {
> > +		dev_err(dev, "%s: tried to set %dx%d, got %dx%d\n", __func__,
> > +				pix->width, pix->height,
> > +				rect->width, rect->height);
> > +		return -EINVAL;
> > +	}
>
> No, that's not an error. Just use whatever you managed to configure.

Let me explain and maybe reimplement correctly my try_fmt() first :).

> > +	return 0;
> > +}
> > +
> > +static int omap1_cam_try_fmt(struct soc_camera_device *icd,
> > +			      struct v4l2_format *f)
> > +{
> > +	struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
> > +	const struct soc_camera_format_xlate *xlate;
> > +	struct device *dev = icd->dev.parent;
> > +	struct v4l2_pix_format *pix = &f->fmt.pix;
> > +	struct v4l2_mbus_framefmt mf, testmf;
> > +	const struct soc_mbus_pixelfmt *fmt;
> > +	int ret;
> > +
> > +	xlate = soc_camera_xlate_by_fourcc(icd, pix->pixelformat);
> > +	if (!xlate) {
> > +		dev_warn(dev, "%s: format %x not found\n", __func__,
> > +				pix->pixelformat);
> > +		return -EINVAL;
> > +	}
> > +
> > +	fmt = xlate->host_fmt;
> > +	ret = dma_align(&pix->width, &pix->height, fmt, true);
> > +	if (ret < 0) {
> > +		dev_err(dev, "%s: failed to align %ux%u %s with DMA\n",
> > +				__func__, pix->width, pix->height, fmt->name);
> > +		return ret;
> > +	}
> > +
> > +	mf.width      = pix->width;
> > +	mf.height     = pix->height;
> > +	mf.field      = pix->field;
> > +	mf.colorspace = pix->colorspace;
> > +	mf.code	      = xlate->code;
> > +
> > +	/* limit to sensor capabilities */
> > +	ret = v4l2_subdev_call(sd, video, try_mbus_fmt, &mf);
> > +	if (ret < 0) {
> > +		dev_err(dev, "%s: try_mbus_fmt() failed\n", __func__);
> > +		return ret;
> > +	}
> > +
> > +	pix->field	= mf.field;
> > +	pix->colorspace	= mf.colorspace;
> > +
> > +	if (mf.width == pix->width && mf.height == pix->height &&
> > +			mf.code == xlate->code)
> > +		return 0;
> > +
> > +	dev_dbg(dev, "%s: geometry changed, recheck alignment\n", __func__);
> > +	pix->width	  = mf.width;
> > +	pix->height	  = mf.height;
>
> This is what the sensor has returned, you put it back into the user frmat.

I hope it's OK.

> > +
> > +	fmt = soc_mbus_get_fmtdesc(mf.code);
> > +	ret = dma_align(&pix->width, &pix->height, fmt, false);
>
> And you DMA-align those sizes.

Shouldn't I?

> > +	if (ret < 0) {
> > +		dev_err(dev, "%s: failed to align %ux%u %s with DMA\n",
> > +				__func__, pix->width, pix->height, fmt->name);
> > +		return ret;
> > +	}
> > +	if (ret)
> > +		return 0;

Maybe the above is not clear enough: ret == 1 means that what we got from the 
sensor is already aligned. If not, we keep processing.

> > +
> > +	testmf.width	  = pix->width;
> > +	testmf.height	  = pix->height;
>
> And use them again for try_fmt

Yes.
For rationale, please see my explanation below.

> > +	testmf.field	  = mf.field;
> > +	testmf.colorspace = mf.colorspace;
> > +	testmf.code	  = mf.code;
> > +
> > +	ret = v4l2_subdev_call(sd, video, try_mbus_fmt, &testmf);
> > +	if (ret < 0) {
> > +		dev_err(dev, "%s: try_mbus_fmt() failed\n", __func__);
> > +		return ret;
> > +	}
> > +
> > +	if (testmf.code != mf.code || testmf.width != mf.width ||
> > +			testmf.height != mf.height) {
> > +		dev_err(dev, "%s: sensor format inconsistency, giving up\n",
> > +				__func__);
> > +		return -EINVAL;
>
> As a general rule, try_fmt shouldn't fail... Only in very weird cases,
> really.

Not being able to negotiate a DMA aligned geometry with the sensor - would it 
be weird enough?

> > +	}
>
> And you verified, the sensor kept them.

The sensor kept previously returend (not aligned) values (stored in mf), not 
those DMA aligned (stored under pix).

> > +	dev_notice(dev, "%s: "
> > +		"sensor frame not DMA aligned, will try to crop from set_fmt()"
>
> Hm? You did align them above? /me confused...

Let me explain how it is all supposed to work:

try_fmt():
1. DMA align a user requested frame geometry.
2. Let the sensor adjust it to its capabilities.
3. If the sensor didn't change the (DMA aligned) geometry, we are done.
4. Otherwise, DMA align it again.
5. If no DMA alignment was necessary on the sensor proposed geometry, we are 
   done as well.
6. Otherwise, check if we still get the same (not aligned) geometry from the 
   sensor if now asking for its DMA alignment result.
7. If the now returned sensor geometry is different from what we got before, 
   we can either restart from 3 (how many iterations?) or fail, I believe.
8. Otherwise, we can accept the sensor geometry that is not DMA aligned, but 
   should return the DMA aligned one, not the sensor provided. We believe to 
   crop the sensor geometry to DMA aligned one during S_FMT.

set_fmt():
1. Since we always return DMA aligned geometry from try_fmt(), expecting it 
   being accepted by a user, we start from checking if what user have 
   requested now is DMA aligned or not.
2. If not DMA aligned, we fail.
   Should we be more polite and try to do our best to accept a geometry that 
   differs from what our try_fmt() could ever return?
3. If DMA aligned, then OK, let the sensor adjust it to its capabilities.
4. If the sensor didn't change the (DMA aligned) geometry, we are done.
5. Otherwise, we assume the sensor returned geometry is not DMA aligned (if it 
   were, we would accept it during try_fmt() before), so it has to be cropped.
   Should we rather retry with S_FMT instead of cropping?
6. If crop gives the geometry requested, we are done.
7. Otherwise, we fail.
   Should we be more cooperative here and accept any valid (ie. DMA aligned) 
   crop result?

> > +		"\n", __func__);
> > +
> > +	return 0;
> > +}

...
> > +	/* apply reset to camera sensor if requested by platform data */
> > +	if (pcdev->pflags & OMAP1_CAMERA_RST_HIGH)
> > +		CAM_WRITE(pcdev, GPIO, 0x1);
> > +	else if (pcdev->pflags & OMAP1_CAMERA_RST_LOW)
> > +		CAM_WRITE(pcdev, GPIO, 0x0);
>
> Why not use sensor_reset()?

Why not... ;)

...
> > +static int __exit omap1_cam_remove(struct platform_device *pdev)
> > +{
> > +	struct soc_camera_host *soc_host = to_soc_camera_host(&pdev->dev);
> > +	struct omap1_cam_dev *pcdev = container_of(soc_host,
> > +					struct omap1_cam_dev, soc_host);
> > +	struct resource *res;
> > +
> > +	soc_camera_host_unregister(soc_host);
> > +
> > +	free_irq(pcdev->irq, pcdev);
> > +
> > +	omap_free_dma(pcdev->dma_ch);
>
> It is probably safer to first shut down the hardware, and only then
> unconfigure software. So, free_irq and free_dma should go first, I think.

OK.

Thanks,
Janusz

Re: [RFC] [PATCH 1/6] SoC Camera: add driver for OMAP1 camera interface

[Janusz Krzysztofik]

Friday 30 July 2010 20:49:05 Janusz Krzysztofik napisał(a):
> Friday 30 July 2010 13:07:42 Guennadi Liakhovetski napisał(a):
> > On Sun, 18 Jul 2010, Janusz Krzysztofik wrote:
> > > This is a V4L2 driver for TI OMAP1 SoC camera interface.
> > >
> > > Two versions of the driver are provided, using either
> > > videobuf-dma-contig or videobuf-dma-sg. The former uses less processing
> > > power, but often fails to allocate contignuous buffer memory. The
> > > latter is free of this problem, but generates tens of DMA interrupts
> > > per frame.
> >
> > Hm, would it be difficult to first try contig, and if it fails - fall
> > back to sg?
>
> Hmm, let me think about it.

Hi Gennadi,

For me, your idea of frist trying contig and then falling back to sg if it 
fails, sounds great. However, I'm not sure if implementing it at a specific 
hardware driver level is a good solution. Nor soc_camera framework seems the 
right place for it either.

I think the right way would be if implemented at the videobuf-core level. 
Then, drivers should be able to initialize both paths, providing queue 
callbacks for both sets of methods, contig and sg, for videobuf sole use.

I'm not sure if I have enough skills to implement this idea. However, if there 
is a consensus on its general usfullness as a videobuf extension, I can have 
a look at it in my spare time.

For now, I'd propose limiting my changes for v2 to splitting both methods into 
separate sections, not interleaved with #ifdefs like they are now, as you've 
already suggested.

Thanks,
Janusz

Re: [RFC] [PATCH 1/6] SoC Camera: add driver for OMAP1 camera interface

[Guennadi Liakhovetski]

On Sun, 1 Aug 2010, Janusz Krzysztofik wrote:

> Friday 30 July 2010 20:49:05 Janusz Krzysztofik napisał(a):
> > Friday 30 July 2010 13:07:42 Guennadi Liakhovetski napisał(a):
> > > On Sun, 18 Jul 2010, Janusz Krzysztofik wrote:
> > > > This is a V4L2 driver for TI OMAP1 SoC camera interface.
> > > >
> > > > Two versions of the driver are provided, using either
> > > > videobuf-dma-contig or videobuf-dma-sg. The former uses less processing
> > > > power, but often fails to allocate contignuous buffer memory. The
> > > > latter is free of this problem, but generates tens of DMA interrupts
> > > > per frame.
> > >
> > > Hm, would it be difficult to first try contig, and if it fails - fall
> > > back to sg?
> >
> > Hmm, let me think about it.
> 
> Hi Gennadi,
> 
> For me, your idea of frist trying contig and then falling back to sg if it 
> fails, sounds great. However, I'm not sure if implementing it at a specific 
> hardware driver level is a good solution. Nor soc_camera framework seems the 
> right place for it either.
> 
> I think the right way would be if implemented at the videobuf-core level. 
> Then, drivers should be able to initialize both paths, providing queue 
> callbacks for both sets of methods, contig and sg, for videobuf sole use.

Ok, here're my thoughts about this:

1. We've discussed this dynamic switching a bit on IRC today. The first 
reaction was - you probably should concentrate on getting the contiguous 
version to work reliably. I.e., to reserve the memory in the board init 
code similar, how other contig users currently do it. But given problems 
with this aproach in the current ARM tree [1], this might be a bit 
difficult. Still, those problems have to be and will be fixed somehow 
eventually, so, you might prefer to still just go that route.

2. If you do want to do the switching - we also discussed, how forthcoming 
changes to the videobuf subsystem will affest this work. I do not think it 
would be possible to implement this switching in the videobuf core. 
Remember, with the videobuf API you first call the respective 
implementation init method, which doesn't fail. Then, in REQBUFS ioctl you 
call videobuf_reqbufs(), which might already fail but normally doesn't. 
The biggest problem is the mmap call with the contig videobuf 
implementation. This one is likely to fail. So, you would have to catch 
the failing mmap, call videobuf_mmap_free(), then init the SG videobuf, 
request buffers and mmap them... With my 2 patches from today, there is 
only one process (file descriptor, to be precise), that manages the 
videobuf queue. So, this all can only be implemented in your driver.

[1] http://thread.gmane.org/gmane.linux.ports.sh.devel/8560

> I'm not sure if I have enough skills to implement this idea. However, if there 
> is a consensus on its general usfullness as a videobuf extension, I can have 
> a look at it in my spare time.
> 
> For now, I'd propose limiting my changes for v2 to splitting both methods into 
> separate sections, not interleaved with #ifdefs like they are now, as you've 
> already suggested.

Yep, so, I think, your choice is either to drop sg completely, or to 
separate the two cleanly and switch between them dynamically in your 
driver.

Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/

Re: [RFC] [PATCH 1/6] SoC Camera: add driver for OMAP1 camera interface

[Janusz Krzysztofik]

Thursday 12 August 2010 23:38:17 Guennadi Liakhovetski napisał(a):
> On Sun, 1 Aug 2010, Janusz Krzysztofik wrote:
> > Friday 30 July 2010 20:49:05 Janusz Krzysztofik napisał(a):
> >
> > I think the right way would be if implemented at the videobuf-core level.
> > Then, drivers should be able to initialize both paths, providing queue
> > callbacks for both sets of methods, contig and sg, for videobuf sole use.
>
> Ok, here're my thoughts about this:
>
> 1. We've discussed this dynamic switching a bit on IRC today. The first
> reaction was - you probably should concentrate on getting the contiguous
> version to work reliably. I.e., to reserve the memory in the board init
> code similar, how other contig users currently do it. 

I already tried before to find out how I could allocate memory at init without 
reinventing a new videobuf-dma-contig implementation. Since in the 
Documentation/video4linux/videobuf I've read that videobuf does not currently 
play well with drivers that play tricks by allocating DMA space at system 
boot time, I've implemented the alternate sg path.

If it's not quite true what the documentation says and you can give me a hint 
how this could be done, I might try again.

> But given problems 
> with this aproach in the current ARM tree [1], this might be a bit
> difficult. Still, those problems have to be and will be fixed somehow
> eventually, so, you might prefer to still just go that route.

My board uses two drivers that allocate dma memory at boot time: 
drivers/video/omap/lcdc.c and sounc/soc/omap/omap-pcm.c. Both use 
alloc_dma_writecombine() for this and work without problems.

> 2. If you do want to do the switching - we also discussed, how forthcoming
> changes to the videobuf subsystem will affest this work. I do not think it
> would be possible to implement this switching in the videobuf core.

OK, I should have probably said that it looked not possible for me to do it 
without any additional support implemented at videobuf-core (or soc_camera) 
level.

> Remember, with the videobuf API you first call the respective
> implementation init method, which doesn't fail. Then, in REQBUFS ioctl you
> call videobuf_reqbufs(), which might already fail but normally doesn't.
> The biggest problem is the mmap call with the contig videobuf
> implementation. This one is likely to fail. So, you would have to catch
> the failing mmap, call videobuf_mmap_free(), then init the SG videobuf,
> request buffers and mmap them... 

That's what I've already discovered, but failed to identify a place in my code 
where I could intercept this failing mmap without replacing parts of the 
videobuf code.

> With my 2 patches from today, there is 
> only one process (file descriptor, to be precise), that manages the
> videobuf queue. So, this all can only be implemented in your driver.

The only way I'm yet able to invent is replacing the 
videobuf_queue->int_ops->mmap_mapper() callback with my own wrapper that 
would intercept a failing videobuf-dma-contig version of mmap_mapper(). This 
could be done in my soc_camera_host->ops->init_videobuf() after the 
videobuf-dma-contig.c version of the videobuf_queue->int_ops->mmap_mapper() 
is installed with the videobuf_queue_dma_contig_init().

Is this method close to what you have on mind?

Thanks,
Janusz

Re: [RFC] [PATCH 1/6] SoC Camera: add driver for OMAP1 camera interface

[Guennadi Liakhovetski]

On Fri, 13 Aug 2010, Janusz Krzysztofik wrote:

> Thursday 12 August 2010 23:38:17 Guennadi Liakhovetski napisał(a):
> > On Sun, 1 Aug 2010, Janusz Krzysztofik wrote:
> > > Friday 30 July 2010 20:49:05 Janusz Krzysztofik napisał(a):
> > >
> > > I think the right way would be if implemented at the videobuf-core level.
> > > Then, drivers should be able to initialize both paths, providing queue
> > > callbacks for both sets of methods, contig and sg, for videobuf sole use.
> >
> > Ok, here're my thoughts about this:
> >
> > 1. We've discussed this dynamic switching a bit on IRC today. The first
> > reaction was - you probably should concentrate on getting the contiguous
> > version to work reliably. I.e., to reserve the memory in the board init
> > code similar, how other contig users currently do it. 
> 
> I already tried before to find out how I could allocate memory at init without 
> reinventing a new videobuf-dma-contig implementation. Since in the 
> Documentation/video4linux/videobuf I've read that videobuf does not currently 
> play well with drivers that play tricks by allocating DMA space at system 
> boot time, I've implemented the alternate sg path.
> 
> If it's not quite true what the documentation says and you can give me a hint 
> how this could be done, I might try again.

For an example look at 
arch/arm/mach-mx3/mach-pcm037.c::pcm037_camera_alloc_dma().

> > But given problems 
> > with this aproach in the current ARM tree [1], this might be a bit
> > difficult. Still, those problems have to be and will be fixed somehow
> > eventually, so, you might prefer to still just go that route.
> 
> My board uses two drivers that allocate dma memory at boot time: 
> drivers/video/omap/lcdc.c and sounc/soc/omap/omap-pcm.c. Both use 
> alloc_dma_writecombine() for this and work without problems.

dma_alloc_writecombine() also allocates contiguous RAM, right? And it 
doesn't use device "local" memory. So, it's chances to fail are the same 
as those of dma_alloc_coherent() in the absence of device own memory. I 
guess, the sound driver doesn't need much RAM, but if you build your LCDC 
driver as a module and load it later after startup, it might get problems 
allocating RAM for the framebuffer.

> > 2. If you do want to do the switching - we also discussed, how forthcoming
> > changes to the videobuf subsystem will affest this work. I do not think it
> > would be possible to implement this switching in the videobuf core.
> 
> OK, I should have probably said that it looked not possible for me to do it 
> without any additional support implemented at videobuf-core (or soc_camera) 
> level.
> 
> > Remember, with the videobuf API you first call the respective
> > implementation init method, which doesn't fail. Then, in REQBUFS ioctl you
> > call videobuf_reqbufs(), which might already fail but normally doesn't.
> > The biggest problem is the mmap call with the contig videobuf
> > implementation. This one is likely to fail. So, you would have to catch
> > the failing mmap, call videobuf_mmap_free(), then init the SG videobuf,
> > request buffers and mmap them... 
> 
> That's what I've already discovered, but failed to identify a place in my code 
> where I could intercept this failing mmap without replacing parts of the 
> videobuf code.

Right, ATM soc-camera just calls videobuf_mmap_mapper() directly in its 
mmap method. I could add a callback to struct soc_camera_host_ops like

	int (*mmap)(struct soc_camera_device *, struct vm_area_struct *)

and modify soc_camera_mmap() to check, whether the host driver has 
implemented it. If so - call it, otherwise call videobuf_mmap_mapper() 
directly just like now. So, other drivers would not have to be modified. 
And you could implement that .mmap() method, call videobuf_mmap_mapper() 
yourself, and if it fails for contig, fall back to SG.

> > With my 2 patches from today, there is 
> > only one process (file descriptor, to be precise), that manages the
> > videobuf queue. So, this all can only be implemented in your driver.
> 
> The only way I'm yet able to invent is replacing the 
> videobuf_queue->int_ops->mmap_mapper() callback with my own wrapper that 
> would intercept a failing videobuf-dma-contig version of mmap_mapper(). This 
> could be done in my soc_camera_host->ops->init_videobuf() after the 
> videobuf-dma-contig.c version of the videobuf_queue->int_ops->mmap_mapper() 
> is installed with the videobuf_queue_dma_contig_init().
> 
> Is this method close to what you have on mind?

See, if the above idea would suit your needs.

Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/

Re: [RFC] [PATCH 1/6] SoC Camera: add driver for OMAP1 camera interface

[Marin Mitov]

On Friday, August 13, 2010 11:52:41 am Guennadi Liakhovetski wrote:
> On Fri, 13 Aug 2010, Janusz Krzysztofik wrote:
> 
> > Thursday 12 August 2010 23:38:17 Guennadi Liakhovetski napisał(a):
> > > On Sun, 1 Aug 2010, Janusz Krzysztofik wrote:
> > > > Friday 30 July 2010 20:49:05 Janusz Krzysztofik napisał(a):
> > > >
> > > > I think the right way would be if implemented at the videobuf-core level.
> > > > Then, drivers should be able to initialize both paths, providing queue
> > > > callbacks for both sets of methods, contig and sg, for videobuf sole use.
> > >
> > > Ok, here're my thoughts about this:
> > >
> > > 1. We've discussed this dynamic switching a bit on IRC today. The first
> > > reaction was - you probably should concentrate on getting the contiguous
> > > version to work reliably. I.e., to reserve the memory in the board init
> > > code similar, how other contig users currently do it. 
> > 
> > I already tried before to find out how I could allocate memory at init without 
> > reinventing a new videobuf-dma-contig implementation. Since in the 
> > Documentation/video4linux/videobuf I've read that videobuf does not currently 
> > play well with drivers that play tricks by allocating DMA space at system 
> > boot time, I've implemented the alternate sg path.
> > 
> > If it's not quite true what the documentation says and you can give me a hint 
> > how this could be done, I might try again.
> 
> For an example look at 
> arch/arm/mach-mx3/mach-pcm037.c::pcm037_camera_alloc_dma().

For preallocating dma-coherent memory for device personal use during device probe() time
(when the memory is less fragmented compared to open() time)
see also dt3155_alloc_coherent/dt3155_free_coherent in drivers/staging/dt3155v4l/dt3155vfl.c
(for x86 arch, I do not know if it works for arm arch)

> 
> > > But given problems 
> > > with this aproach in the current ARM tree [1], this might be a bit
> > > difficult. Still, those problems have to be and will be fixed somehow
> > > eventually, so, you might prefer to still just go that route.
> > 
> > My board uses two drivers that allocate dma memory at boot time: 
> > drivers/video/omap/lcdc.c and sounc/soc/omap/omap-pcm.c. Both use 
> > alloc_dma_writecombine() for this and work without problems.
> 
> dma_alloc_writecombine() also allocates contiguous RAM, right? And it 
> doesn't use device "local" memory. So, it's chances to fail are the same 
> as those of dma_alloc_coherent() in the absence of device own memory. I 
> guess, the sound driver doesn't need much RAM, but if you build your LCDC 
> driver as a module and load it later after startup, it might get problems 
> allocating RAM for the framebuffer.
> 
> > > 2. If you do want to do the switching - we also discussed, how forthcoming
> > > changes to the videobuf subsystem will affest this work. I do not think it
> > > would be possible to implement this switching in the videobuf core.
> > 
> > OK, I should have probably said that it looked not possible for me to do it 
> > without any additional support implemented at videobuf-core (or soc_camera) 
> > level.
> > 
> > > Remember, with the videobuf API you first call the respective
> > > implementation init method, which doesn't fail. Then, in REQBUFS ioctl you
> > > call videobuf_reqbufs(), which might already fail but normally doesn't.
> > > The biggest problem is the mmap call with the contig videobuf
> > > implementation. This one is likely to fail. So, you would have to catch
> > > the failing mmap, call videobuf_mmap_free(), then init the SG videobuf,
> > > request buffers and mmap them... 
> > 
> > That's what I've already discovered, but failed to identify a place in my code 
> > where I could intercept this failing mmap without replacing parts of the 
> > videobuf code.
> 
> Right, ATM soc-camera just calls videobuf_mmap_mapper() directly in its 
> mmap method. I could add a callback to struct soc_camera_host_ops like
> 
> 	int (*mmap)(struct soc_camera_device *, struct vm_area_struct *)
> 
> and modify soc_camera_mmap() to check, whether the host driver has 
> implemented it. If so - call it, otherwise call videobuf_mmap_mapper() 
> directly just like now. So, other drivers would not have to be modified. 
> And you could implement that .mmap() method, call videobuf_mmap_mapper() 
> yourself, and if it fails for contig, fall back to SG.
> 
> > > With my 2 patches from today, there is 
> > > only one process (file descriptor, to be precise), that manages the
> > > videobuf queue. So, this all can only be implemented in your driver.
> > 
> > The only way I'm yet able to invent is replacing the 
> > videobuf_queue->int_ops->mmap_mapper() callback with my own wrapper that 
> > would intercept a failing videobuf-dma-contig version of mmap_mapper(). This 
> > could be done in my soc_camera_host->ops->init_videobuf() after the 
> > videobuf-dma-contig.c version of the videobuf_queue->int_ops->mmap_mapper() 
> > is installed with the videobuf_queue_dma_contig_init().
> > 
> > Is this method close to what you have on mind?
> 
> See, if the above idea would suit your needs.
> 
> Thanks
> Guennadi
> ---
> Guennadi Liakhovetski, Ph.D.
> Freelance Open-Source Software Developer
> http://www.open-technology.de/
> --
> To unsubscribe from this list: send the line "unsubscribe linux-media" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

Re: [RFC] [PATCH 1/6] SoC Camera: add driver for OMAP1 camera interface

[Janusz Krzysztofik]

Friday 13 August 2010 11:11:52 Marin Mitov napisał(a):
> On Friday, August 13, 2010 11:52:41 am Guennadi Liakhovetski wrote:
> > On Fri, 13 Aug 2010, Janusz Krzysztofik wrote:
> > > Thursday 12 August 2010 23:38:17 Guennadi Liakhovetski napisał(a):
> > > > 1. We've discussed this dynamic switching a bit on IRC today. The
> > > > first reaction was - you probably should concentrate on getting the
> > > > contiguous version to work reliably. I.e., to reserve the memory in
> > > > the board init code similar, how other contig users currently do it.
> > >
> > > I already tried before to find out how I could allocate memory at init
> > > without reinventing a new videobuf-dma-contig implementation. Since in
> > > the Documentation/video4linux/videobuf I've read that videobuf does not
> > > currently play well with drivers that play tricks by allocating DMA
> > > space at system boot time, I've implemented the alternate sg path.
> > >
> > > If it's not quite true what the documentation says and you can give me
> > > a hint how this could be done, I might try again.
> >
> > For an example look at
> > arch/arm/mach-mx3/mach-pcm037.c::pcm037_camera_alloc_dma().

Yes, this is the solution that suffers from the already discussed limitation 
of not being able to remap a memory with different attributes, which affects 
OMAP1 as well.

> For preallocating dma-coherent memory for device personal use during device
> probe() time (when the memory is less fragmented compared to open() time)
> see also dt3155_alloc_coherent/dt3155_free_coherent in
> drivers/staging/dt3155v4l/dt3155vfl.c (for x86 arch, I do not know if it
> works for arm arch)

With this workaround applied, I get much better results, thank you Marin. 
However, it seems not bullet proof, since mmap still happens to fail for a 
reason not quite clear to me:

[ 6067.220000] omap1-camera omap1-camera.0: OMAP1 Camera driver attached to camera 0
[ 6067.650000] omap1-camera omap1-camera.0: omap1_cam_try_fmt: format 32315659 not found
[ 6067.680000] omap1-camera omap1-camera.0: omap1_cam_try_fmt: format 32315559 not found
[ 6068.480000] mplayer: page allocation failure. order:6, mode:0xd0
[ 6068.500000] Backtrace:
[ 6068.520000] [<c0028950>] (dump_backtrace+0x0/0x110) from [<c0028ea8>] (dump_stack+0x18/0x1c)
[ 6068.560000]  r6:00000006 r5:000000d0 r4:c1bcf000
[ 6068.590000] [<c0028e90>] (dump_stack+0x0/0x1c) from [<c0074e24>] (__alloc_pages_nodemask+0x504/0x560)
[ 6068.620000] [<c0074920>] (__alloc_pages_nodemask+0x0/0x560) from [<c002ae14>] (__dma_alloc+0x108/0x354)
[ 6068.660000] [<c002ad0c>] (__dma_alloc+0x0/0x354) from [<c002b0ec>] (dma_alloc_coherent+0x58/0x64)
[ 6068.700000] [<c002b094>] (dma_alloc_coherent+0x0/0x64) from [<bf000a44>] (__videobuf_mmap_mapper+0x10c/0x374 [videobuf_dma_contig])
[ 6068.740000]  r7:c16934c0 r6:00000000 r5:c171baec r4:00000000
[ 6068.770000] [<bf000938>] (__videobuf_mmap_mapper+0x0/0x374 [videobuf_dma_contig]) from [<c01f9a78>] (videobuf_mmap_mapper+0xc4/0x108)
[ 6068.810000] [<c01f99b4>] (videobuf_mmap_mapper+0x0/0x108) from [<c01fc1ac>] (soc_camera_mmap+0x80/0x140)
[ 6068.840000]  r5:c1a3b4e0 r4:00000000
[ 6068.870000] [<c01fc12c>] (soc_camera_mmap+0x0/0x140) from [<c01eeba8>] (v4l2_mmap+0x4c/0x5c)
[ 6068.900000]  r7:c145c000 r6:000000ff r5:c16934c0 r4:00000000
[ 6068.930000] [<c01eeb5c>] (v4l2_mmap+0x0/0x5c) from [<c0085de4>] (mmap_region+0x238/0x458)
[ 6068.970000] [<c0085bac>] (mmap_region+0x0/0x458) from [<c00862c0>] (do_mmap_pgoff+0x2bc/0x320)
[ 6069.000000] [<c0086004>] (do_mmap_pgoff+0x0/0x320) from [<c00863c0>] (sys_mmap_pgoff+0x9c/0xc8)
[ 6069.040000] [<c0086324>] (sys_mmap_pgoff+0x0/0xc8) from [<c0024f00>] (ret_fast_syscall+0x0/0x2c)
[ 6069.200000] Mem-info:
[ 6069.220000] Normal per-cpu:
[ 6069.240000] CPU    0: hi:    0, btch:   1 usd:   0
[ 6069.260000] active_anon:676 inactive_anon:682 isolated_anon:0
[ 6069.260000]  active_file:422 inactive_file:2348 isolated_file:0
[ 6069.260000]  unevictable:177 dirty:0 writeback:0 unstable:0
[ 6069.260000]  free:1166 slab_reclaimable:0 slab_unreclaimable:0
[ 6069.260000]  mapped:1120 shmem:0 pagetables:121 bounce:0
[ 6069.350000] Normal free:4664kB min:720kB low:900kB high:1080kB active_anon:2704kB inactive_anon:2728kB active_file:1688kB inactive_file:9392kB unevictable:708kB isolated(anon):0kB isolated(file):0kB present:32512kB mlocked:0kB 
dirty:0kB writeback:0kB mapped:4480kB shmem:0kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:552kB pagetables:484kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no
[ 6069.460000] lowmem_reserve[]: 0 0
[ 6069.470000] Normal: 6*4kB 20*8kB 14*16kB 29*32kB 26*64kB 9*128kB 2*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 4664kB
[ 6069.530000] 2960 total pagecache pages
[ 6069.550000] 8192 pages of RAM
[ 6069.560000] 1322 free pages
[ 6069.580000] 1114 reserved pages
[ 6069.590000] 750 slab pages
[ 6069.610000] 2476 pages shared
[ 6069.630000] 0 pages swap cached
[ 6069.640000] omap1-camera omap1-camera.0: dma_alloc_coherent size 204800 failed
[ 6069.680000] omap1-camera omap1-camera.0: OMAP1 Camera driver detached from camera 0

Maybe I should preallocate a few more pages than will be actually used by the 
driver?

Anyways, I'm not sure if this piece of code could be accepted for inclusion 
into the mainline tree, perhaps only under drivers/staging.

Thanks,
Janusz

Re: [RFC] [PATCH 1/6] SoC Camera: add driver for OMAP1 camera interface

[Marin Mitov]

On Friday, August 13, 2010 10:13:08 pm Janusz Krzysztofik wrote:
> Friday 13 August 2010 11:11:52 Marin Mitov napisał(a):
> > On Friday, August 13, 2010 11:52:41 am Guennadi Liakhovetski wrote:
> > > On Fri, 13 Aug 2010, Janusz Krzysztofik wrote:
> > > > Thursday 12 August 2010 23:38:17 Guennadi Liakhovetski napisał(a):
> > > > > 1. We've discussed this dynamic switching a bit on IRC today. The
> > > > > first reaction was - you probably should concentrate on getting the
> > > > > contiguous version to work reliably. I.e., to reserve the memory in
> > > > > the board init code similar, how other contig users currently do it.
> > > >
> > > > I already tried before to find out how I could allocate memory at init
> > > > without reinventing a new videobuf-dma-contig implementation. Since in
> > > > the Documentation/video4linux/videobuf I've read that videobuf does not
> > > > currently play well with drivers that play tricks by allocating DMA
> > > > space at system boot time, I've implemented the alternate sg path.
> > > >
> > > > If it's not quite true what the documentation says and you can give me
> > > > a hint how this could be done, I might try again.
> > >
> > > For an example look at
> > > arch/arm/mach-mx3/mach-pcm037.c::pcm037_camera_alloc_dma().
> 
> Yes, this is the solution that suffers from the already discussed limitation 
> of not being able to remap a memory with different attributes, which affects 
> OMAP1 as well.
> 
> > For preallocating dma-coherent memory for device personal use during device
> > probe() time (when the memory is less fragmented compared to open() time)
> > see also dt3155_alloc_coherent/dt3155_free_coherent in
> > drivers/staging/dt3155v4l/dt3155vfl.c (for x86 arch, I do not know if it
> > works for arm arch)
> 
> With this workaround applied, I get much better results, thank you Marin. 
> However, it seems not bullet proof, since mmap still happens to fail for a 
> reason not quite clear to me:
> 

This is just a preallocation of coherent memory kept for further private driver use, 
should not be connected to mmap problem.

> 
> Maybe I should preallocate a few more pages than will be actually used by the 
> driver?
> 
> Anyways, I'm not sure if this piece of code could be accepted for inclusion 
> into the mainline tree, perhaps only under drivers/staging.

The idea for the piece of code I have proposed to you is taken from the functions
dma_declare_coherent_memory()/dma_release_declared_memory() in mainline 
drivers/base/dma-coherent.c

> 
> Thanks,
> Janusz
> 

Re: [RFC] [PATCH 1/6] SoC Camera: add driver for OMAP1 camera interface

[Janusz Krzysztofik]

Saturday 14 August 2010 06:47:56 Marin Mitov napisał(a):
> On Friday, August 13, 2010 10:13:08 pm Janusz Krzysztofik wrote:
> > Friday 13 August 2010 11:11:52 Marin Mitov napisał(a):
> > > On Friday, August 13, 2010 11:52:41 am Guennadi Liakhovetski wrote:
> > > > On Fri, 13 Aug 2010, Janusz Krzysztofik wrote:
> > > > > Thursday 12 August 2010 23:38:17 Guennadi Liakhovetski napisał(a):
> > > > > > 1. We've discussed this dynamic switching a bit on IRC today. The
> > > > > > first reaction was - you probably should concentrate on getting
> > > > > > the contiguous version to work reliably. I.e., to reserve the
> > > > > > memory in the board init code similar, how other contig users
> > > > > > currently do it.
> > > > >
> > > > > I already tried before to find out how I could allocate memory at
> > > > > init without reinventing a new videobuf-dma-contig implementation.
> > > > > Since in the Documentation/video4linux/videobuf I've read that
> > > > > videobuf does not currently play well with drivers that play tricks
> > > > > by allocating DMA space at system boot time, I've implemented the
> > > > > alternate sg path.
> > > > >
> > > > > If it's not quite true what the documentation says and you can give
> > > > > me a hint how this could be done, I might try again.
> > > >
> > > > For an example look at
> > > > arch/arm/mach-mx3/mach-pcm037.c::pcm037_camera_alloc_dma().
> >
> > Yes, this is the solution that suffers from the already discussed
> > limitation of not being able to remap a memory with different attributes,
> > which affects OMAP1 as well.
> >
> > > For preallocating dma-coherent memory for device personal use during
> > > device probe() time (when the memory is less fragmented compared to
> > > open() time) see also dt3155_alloc_coherent/dt3155_free_coherent in
> > > drivers/staging/dt3155v4l/dt3155vfl.c (for x86 arch, I do not know if
> > > it works for arm arch)
> >
> > With this workaround applied, I get much better results, thank you Marin.
> > However, it seems not bullet proof, since mmap still happens to fail for
> > a reason not quite clear to me:
>
> This is just a preallocation of coherent memory kept for further private
> driver use, should not be connected to mmap problem.

I'm not sure if it is related or not. This "mmap problem" exhibits ultimately 
when my driver is trying to allocate a piece of memory that has been 
preallocated that "custom" way.

> > Maybe I should preallocate a few more pages than will be actually used by
> > the driver?
> >
> > Anyways, I'm not sure if this piece of code could be accepted for
> > inclusion into the mainline tree, perhaps only under drivers/staging.
>
> The idea for the piece of code I have proposed to you is taken from the
> functions dma_declare_coherent_memory()/dma_release_declared_memory() in
> mainline drivers/base/dma-coherent.c

Then why not using the dma_declare_coherent_memory(), possibly after providing 
a patch that corrects a problem with it if there is one, instead of 
reimplementing it inside a driver?

If I understood what a difference it could make if we put a 
dma_alloc_coherent() returned virtual address space pointer to the allocated 
region, instead of the ioremapped physical address base of this region, to 
the dev->dma_mem->virt_base, then maybe I could say something more on this.

Thanks,
Janusz

Re: [RFC] [PATCH 1/6] SoC Camera: add driver for OMAP1 camera interface

[Guennadi Liakhovetski]

On Fri, 13 Aug 2010, Janusz Krzysztofik wrote:

> Friday 13 August 2010 11:11:52 Marin Mitov napisał(a):
> > On Friday, August 13, 2010 11:52:41 am Guennadi Liakhovetski wrote:
> > > On Fri, 13 Aug 2010, Janusz Krzysztofik wrote:
> > > > Thursday 12 August 2010 23:38:17 Guennadi Liakhovetski napisał(a):
> > > > > 1. We've discussed this dynamic switching a bit on IRC today. The
> > > > > first reaction was - you probably should concentrate on getting the
> > > > > contiguous version to work reliably. I.e., to reserve the memory in
> > > > > the board init code similar, how other contig users currently do it.
> > > >
> > > > I already tried before to find out how I could allocate memory at init
> > > > without reinventing a new videobuf-dma-contig implementation. Since in
> > > > the Documentation/video4linux/videobuf I've read that videobuf does not
> > > > currently play well with drivers that play tricks by allocating DMA
> > > > space at system boot time, I've implemented the alternate sg path.
> > > >
> > > > If it's not quite true what the documentation says and you can give me
> > > > a hint how this could be done, I might try again.
> > >
> > > For an example look at
> > > arch/arm/mach-mx3/mach-pcm037.c::pcm037_camera_alloc_dma().
> 
> Yes, this is the solution that suffers from the already discussed limitation 
> of not being able to remap a memory with different attributes, which affects 
> OMAP1 as well.
> 
> > For preallocating dma-coherent memory for device personal use during device
> > probe() time (when the memory is less fragmented compared to open() time)
> > see also dt3155_alloc_coherent/dt3155_free_coherent in
> > drivers/staging/dt3155v4l/dt3155vfl.c (for x86 arch, I do not know if it
> > works for arm arch)
> 
> With this workaround applied, I get much better results, thank you Marin. 
> However, it seems not bullet proof, since mmap still happens to fail for a 
> reason not quite clear to me:

What exactly does this mean - happens to fail - you mean starting and 
stopping mplayer several times? Can you verify, that you're not leaking 
memory? That you're freeing all allocated DMA memory again? Are you using 
the same parameters to mplayer, right?

As for the work-around - can you not do this in your board late-initcall 
function?

Not sure whether and how one can get this in the mainline. This is in 
principle the same, as in the above dma_declare_coherent_memory() example, 
only open-coded without the ioremap. Maybe we can add a suitable function 
to the dma-alloc API...

Thanks
Guennadi

> 
> [ 6067.220000] omap1-camera omap1-camera.0: OMAP1 Camera driver attached to camera 0
> [ 6067.650000] omap1-camera omap1-camera.0: omap1_cam_try_fmt: format 32315659 not found
> [ 6067.680000] omap1-camera omap1-camera.0: omap1_cam_try_fmt: format 32315559 not found
> [ 6068.480000] mplayer: page allocation failure. order:6, mode:0xd0
> [ 6068.500000] Backtrace:
> [ 6068.520000] [<c0028950>] (dump_backtrace+0x0/0x110) from [<c0028ea8>] (dump_stack+0x18/0x1c)
> [ 6068.560000]  r6:00000006 r5:000000d0 r4:c1bcf000
> [ 6068.590000] [<c0028e90>] (dump_stack+0x0/0x1c) from [<c0074e24>] (__alloc_pages_nodemask+0x504/0x560)
> [ 6068.620000] [<c0074920>] (__alloc_pages_nodemask+0x0/0x560) from [<c002ae14>] (__dma_alloc+0x108/0x354)
> [ 6068.660000] [<c002ad0c>] (__dma_alloc+0x0/0x354) from [<c002b0ec>] (dma_alloc_coherent+0x58/0x64)
> [ 6068.700000] [<c002b094>] (dma_alloc_coherent+0x0/0x64) from [<bf000a44>] (__videobuf_mmap_mapper+0x10c/0x374 [videobuf_dma_contig])
> [ 6068.740000]  r7:c16934c0 r6:00000000 r5:c171baec r4:00000000
> [ 6068.770000] [<bf000938>] (__videobuf_mmap_mapper+0x0/0x374 [videobuf_dma_contig]) from [<c01f9a78>] (videobuf_mmap_mapper+0xc4/0x108)
> [ 6068.810000] [<c01f99b4>] (videobuf_mmap_mapper+0x0/0x108) from [<c01fc1ac>] (soc_camera_mmap+0x80/0x140)
> [ 6068.840000]  r5:c1a3b4e0 r4:00000000
> [ 6068.870000] [<c01fc12c>] (soc_camera_mmap+0x0/0x140) from [<c01eeba8>] (v4l2_mmap+0x4c/0x5c)
> [ 6068.900000]  r7:c145c000 r6:000000ff r5:c16934c0 r4:00000000
> [ 6068.930000] [<c01eeb5c>] (v4l2_mmap+0x0/0x5c) from [<c0085de4>] (mmap_region+0x238/0x458)
> [ 6068.970000] [<c0085bac>] (mmap_region+0x0/0x458) from [<c00862c0>] (do_mmap_pgoff+0x2bc/0x320)
> [ 6069.000000] [<c0086004>] (do_mmap_pgoff+0x0/0x320) from [<c00863c0>] (sys_mmap_pgoff+0x9c/0xc8)
> [ 6069.040000] [<c0086324>] (sys_mmap_pgoff+0x0/0xc8) from [<c0024f00>] (ret_fast_syscall+0x0/0x2c)
> [ 6069.200000] Mem-info:
> [ 6069.220000] Normal per-cpu:
> [ 6069.240000] CPU    0: hi:    0, btch:   1 usd:   0
> [ 6069.260000] active_anon:676 inactive_anon:682 isolated_anon:0
> [ 6069.260000]  active_file:422 inactive_file:2348 isolated_file:0
> [ 6069.260000]  unevictable:177 dirty:0 writeback:0 unstable:0
> [ 6069.260000]  free:1166 slab_reclaimable:0 slab_unreclaimable:0
> [ 6069.260000]  mapped:1120 shmem:0 pagetables:121 bounce:0
> [ 6069.350000] Normal free:4664kB min:720kB low:900kB high:1080kB active_anon:2704kB inactive_anon:2728kB active_file:1688kB inactive_file:9392kB unevictable:708kB isolated(anon):0kB isolated(file):0kB present:32512kB mlocked:0kB 
> dirty:0kB writeback:0kB mapped:4480kB shmem:0kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:552kB pagetables:484kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no
> [ 6069.460000] lowmem_reserve[]: 0 0
> [ 6069.470000] Normal: 6*4kB 20*8kB 14*16kB 29*32kB 26*64kB 9*128kB 2*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 4664kB
> [ 6069.530000] 2960 total pagecache pages
> [ 6069.550000] 8192 pages of RAM
> [ 6069.560000] 1322 free pages
> [ 6069.580000] 1114 reserved pages
> [ 6069.590000] 750 slab pages
> [ 6069.610000] 2476 pages shared
> [ 6069.630000] 0 pages swap cached
> [ 6069.640000] omap1-camera omap1-camera.0: dma_alloc_coherent size 204800 failed
> [ 6069.680000] omap1-camera omap1-camera.0: OMAP1 Camera driver detached from camera 0
> 
> Maybe I should preallocate a few more pages than will be actually used by the 
> driver?
> 
> Anyways, I'm not sure if this piece of code could be accepted for inclusion 
> into the mainline tree, perhaps only under drivers/staging.
> 
> Thanks,
> Janusz
> 

---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/

Re: [RFC] [PATCH 1/6] SoC Camera: add driver for OMAP1 camera interface

[Janusz Krzysztofik]

Saturday 14 August 2010 19:33:09 Guennadi Liakhovetski napisał(a):
> On Fri, 13 Aug 2010, Janusz Krzysztofik wrote:
> > Friday 13 August 2010 11:11:52 Marin Mitov napisał(a):
> > > On Friday, August 13, 2010 11:52:41 am Guennadi Liakhovetski wrote:
> > > > On Fri, 13 Aug 2010, Janusz Krzysztofik wrote:
> > > > > Thursday 12 August 2010 23:38:17 Guennadi Liakhovetski napisał(a):
> > > > > > 1. We've discussed this dynamic switching a bit on IRC today. The
> > > > > > first reaction was - you probably should concentrate on getting
> > > > > > the contiguous version to work reliably. I.e., to reserve the
> > > > > > memory in the board init code similar, how other contig users
> > > > > > currently do it.
> > > > >
> > > > > I already tried before to find out how I could allocate memory at
> > > > > init without reinventing a new videobuf-dma-contig implementation.
> > > > > Since in the Documentation/video4linux/videobuf I've read that
> > > > > videobuf does not currently play well with drivers that play tricks
> > > > > by allocating DMA space at system boot time, I've implemented the
> > > > > alternate sg path.
> > > > >
> > > > > If it's not quite true what the documentation says and you can give
> > > > > me a hint how this could be done, I might try again.
> > > >
> > > > For an example look at
> > > > arch/arm/mach-mx3/mach-pcm037.c::pcm037_camera_alloc_dma().
> >
> > Yes, this is the solution that suffers from the already discussed
> > limitation of not being able to remap a memory with different attributes,
> > which affects OMAP1 as well.
> >
> > > For preallocating dma-coherent memory for device personal use during
> > > device probe() time (when the memory is less fragmented compared to
> > > open() time) see also dt3155_alloc_coherent/dt3155_free_coherent in
> > > drivers/staging/dt3155v4l/dt3155vfl.c (for x86 arch, I do not know if
> > > it works for arm arch)
> >
> > With this workaround applied, I get much better results, thank you Marin.
> > However, it seems not bullet proof, since mmap still happens to fail for
> > a reason not quite clear to me:
>
> What exactly does this mean - happens to fail - you mean starting and
> stopping mplayer several times? 

What I am able to reproduce is a failure on very first camera access after 
boot. Then, it seems working as expected for subsequent accesses, as long as 
there is no other activity (VoIP or video over bluetooth PAN in my case). 
Then, it usualy fails once, and starts working back againg. However, it 
happened once that it broke permanently after a bluetooth related error.

Without the work-around, it works after boot for ca. 50% tries, then, after 
some VoIP or video over PAN activity, refuses to allocate memory for DMA any 
longer.

IOW, the work-around helps, but doesn't provide a 100% guarrantee.

> Can you verify, that you're not leaking 
> memory? That you're freeing all allocated DMA memory again? Are you using
> the same parameters to mplayer, right?

I've been using the same testing procedure for the last 2-3 months, since I 
started the driver development. It never failed to allocate DMA memory for SG 
mode.

> As for the work-around - can you not do this in your board late-initcall
> function?

One of the arguments of this custom fuction is the camera interface device 
structre pointer. I don't know how I could get access to this pointer from my 
board code.

> Not sure whether and how one can get this in the mainline. This is in
> principle the same, as in the above dma_declare_coherent_memory() example,
> only open-coded without the ioremap. Maybe we can add a suitable function
> to the dma-alloc API...

With my limited skills, I'd rather wait for a solution promissed by RMK for 
next merge window ;).

Thanks,
Janusz


> Thanks
> Guennadi
>
> > [ 6067.220000] omap1-camera omap1-camera.0: OMAP1 Camera driver attached
> > to camera 0 [ 6067.650000] omap1-camera omap1-camera.0:
> > omap1_cam_try_fmt: format 32315659 not found [ 6067.680000] omap1-camera
> > omap1-camera.0: omap1_cam_try_fmt: format 32315559 not found [
> > 6068.480000] mplayer: page allocation failure. order:6, mode:0xd0 [
> > 6068.500000] Backtrace:
> > [ 6068.520000] [<c0028950>] (dump_backtrace+0x0/0x110) from [<c0028ea8>]
> > (dump_stack+0x18/0x1c) [ 6068.560000]  r6:00000006 r5:000000d0
> > r4:c1bcf000
> > [ 6068.590000] [<c0028e90>] (dump_stack+0x0/0x1c) from [<c0074e24>]
> > (__alloc_pages_nodemask+0x504/0x560) [ 6068.620000] [<c0074920>]
> > (__alloc_pages_nodemask+0x0/0x560) from [<c002ae14>]
> > (__dma_alloc+0x108/0x354) [ 6068.660000] [<c002ad0c>]
> > (__dma_alloc+0x0/0x354) from [<c002b0ec>] (dma_alloc_coherent+0x58/0x64)
> > [ 6068.700000] [<c002b094>] (dma_alloc_coherent+0x0/0x64) from
> > [<bf000a44>] (__videobuf_mmap_mapper+0x10c/0x374 [videobuf_dma_contig]) [
> > 6068.740000]  r7:c16934c0 r6:00000000 r5:c171baec r4:00000000
> > [ 6068.770000] [<bf000938>] (__videobuf_mmap_mapper+0x0/0x374
> > [videobuf_dma_contig]) from [<c01f9a78>]
> > (videobuf_mmap_mapper+0xc4/0x108) [ 6068.810000] [<c01f99b4>]
> > (videobuf_mmap_mapper+0x0/0x108) from [<c01fc1ac>]
> > (soc_camera_mmap+0x80/0x140) [ 6068.840000]  r5:c1a3b4e0 r4:00000000
> > [ 6068.870000] [<c01fc12c>] (soc_camera_mmap+0x0/0x140) from [<c01eeba8>]
> > (v4l2_mmap+0x4c/0x5c) [ 6068.900000]  r7:c145c000 r6:000000ff r5:c16934c0
> > r4:00000000
> > [ 6068.930000] [<c01eeb5c>] (v4l2_mmap+0x0/0x5c) from [<c0085de4>]
> > (mmap_region+0x238/0x458) [ 6068.970000] [<c0085bac>]
> > (mmap_region+0x0/0x458) from [<c00862c0>] (do_mmap_pgoff+0x2bc/0x320) [
> > 6069.000000] [<c0086004>] (do_mmap_pgoff+0x0/0x320) from [<c00863c0>]
> > (sys_mmap_pgoff+0x9c/0xc8) [ 6069.040000] [<c0086324>]
> > (sys_mmap_pgoff+0x0/0xc8) from [<c0024f00>] (ret_fast_syscall+0x0/0x2c) [
> > 6069.200000] Mem-info:
> > [ 6069.220000] Normal per-cpu:
> > [ 6069.240000] CPU    0: hi:    0, btch:   1 usd:   0
> > [ 6069.260000] active_anon:676 inactive_anon:682 isolated_anon:0
> > [ 6069.260000]  active_file:422 inactive_file:2348 isolated_file:0
> > [ 6069.260000]  unevictable:177 dirty:0 writeback:0 unstable:0
> > [ 6069.260000]  free:1166 slab_reclaimable:0 slab_unreclaimable:0
> > [ 6069.260000]  mapped:1120 shmem:0 pagetables:121 bounce:0
> > [ 6069.350000] Normal free:4664kB min:720kB low:900kB high:1080kB
> > active_anon:2704kB inactive_anon:2728kB active_file:1688kB
> > inactive_file:9392kB unevictable:708kB isolated(anon):0kB
> > isolated(file):0kB present:32512kB mlocked:0kB dirty:0kB writeback:0kB
> > mapped:4480kB shmem:0kB slab_reclaimable:0kB slab_unreclaimable:0kB
> > kernel_stack:552kB pagetables:484kB unstable:0kB bounce:0kB
> > writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no [ 6069.460000]
> > lowmem_reserve[]: 0 0
> > [ 6069.470000] Normal: 6*4kB 20*8kB 14*16kB 29*32kB 26*64kB 9*128kB
> > 2*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 4664kB [ 6069.530000] 2960
> > total pagecache pages
> > [ 6069.550000] 8192 pages of RAM
> > [ 6069.560000] 1322 free pages
> > [ 6069.580000] 1114 reserved pages
> > [ 6069.590000] 750 slab pages
> > [ 6069.610000] 2476 pages shared
> > [ 6069.630000] 0 pages swap cached
> > [ 6069.640000] omap1-camera omap1-camera.0: dma_alloc_coherent size
> > 204800 failed [ 6069.680000] omap1-camera omap1-camera.0: OMAP1 Camera
> > driver detached from camera 0
> >
> > Maybe I should preallocate a few more pages than will be actually used by
> > the driver?
> >
> > Anyways, I'm not sure if this piece of code could be accepted for
> > inclusion into the mainline tree, perhaps only under drivers/staging.
> >
> > Thanks,
> > Janusz
>
> ---
> Guennadi Liakhovetski, Ph.D.
> Freelance Open-Source Software Developer
> http://www.open-technology.de/
> --
> To unsubscribe from this list: send the line "unsubscribe linux-media" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [RFC] [PATCH 1/6] SoC Camera: add driver for OMAP1 camera interface

[Marin Mitov]

On Saturday, August 14, 2010 08:33:09 pm Guennadi Liakhovetski wrote:
> On Fri, 13 Aug 2010, Janusz Krzysztofik wrote:
> 
> > Friday 13 August 2010 11:11:52 Marin Mitov napisał(a):
> > > On Friday, August 13, 2010 11:52:41 am Guennadi Liakhovetski wrote:
> > > > On Fri, 13 Aug 2010, Janusz Krzysztofik wrote:
> > > > > Thursday 12 August 2010 23:38:17 Guennadi Liakhovetski napisał(a):
> > > > > > 1. We've discussed this dynamic switching a bit on IRC today. The
> > > > > > first reaction was - you probably should concentrate on getting the
> > > > > > contiguous version to work reliably. I.e., to reserve the memory in
> > > > > > the board init code similar, how other contig users currently do it.
> > > > >
> > > > > I already tried before to find out how I could allocate memory at init
> > > > > without reinventing a new videobuf-dma-contig implementation. Since in
> > > > > the Documentation/video4linux/videobuf I've read that videobuf does not
> > > > > currently play well with drivers that play tricks by allocating DMA
> > > > > space at system boot time, I've implemented the alternate sg path.
> > > > >
> > > > > If it's not quite true what the documentation says and you can give me
> > > > > a hint how this could be done, I might try again.
> > > >
> > > > For an example look at
> > > > arch/arm/mach-mx3/mach-pcm037.c::pcm037_camera_alloc_dma().
> > 
> > Yes, this is the solution that suffers from the already discussed limitation 
> > of not being able to remap a memory with different attributes, which affects 
> > OMAP1 as well.
> > 
> > > For preallocating dma-coherent memory for device personal use during device
> > > probe() time (when the memory is less fragmented compared to open() time)
> > > see also dt3155_alloc_coherent/dt3155_free_coherent in
> > > drivers/staging/dt3155v4l/dt3155vfl.c (for x86 arch, I do not know if it
> > > works for arm arch)
> > 
> > With this workaround applied, I get much better results, thank you Marin. 
> > However, it seems not bullet proof, since mmap still happens to fail for a 
> > reason not quite clear to me:
> 
> What exactly does this mean - happens to fail - you mean starting and 
> stopping mplayer several times? Can you verify, that you're not leaking 
> memory? That you're freeing all allocated DMA memory again? Are you using 
> the same parameters to mplayer, right?
> 
> As for the work-around - can you not do this in your board late-initcall 
> function?
> 
> Not sure whether and how one can get this in the mainline. This is in 
> principle the same, as in the above dma_declare_coherent_memory() example, 
> only open-coded without the ioremap. 

My believe is that dma_declare_coherent_memory() could be used if your frame grabber
has local RAM buffer (like video buffer if the graphic adapters) defined by BAR - that is
why you need ioremap(). If this RAM turns out to be coherent you use 
dma_declare_coherent_memory() and any further invocation of dma_alloc_coherent() 
will allocate from it (till it is exosted). My use of dt3155_alloc_coherent()/dt3155_free_coherent() 
is to allocate a block of coherent 4MB memory during driver probe() method and use it latter 
(via videobuff_dma_contig framework)).

> Maybe we can add a suitable function 
> to the dma-alloc API...

Could be of general use, I am thinking about this. This could be done by just renaming
dt3155_alloc_coherent()/dt3155_free_coherent() to something acceptable 
(dma_reserve_coherent_memory()/dma_release_reserved_memory(), I am open for suggestions) 
and export them. Should be added to drivers/base/dma-coherent.c.

Marin Mitov

> 
> Thanks
> Guennadi
> 
> > 
> > [ 6067.220000] omap1-camera omap1-camera.0: OMAP1 Camera driver attached to camera 0
> > [ 6067.650000] omap1-camera omap1-camera.0: omap1_cam_try_fmt: format 32315659 not found
> > [ 6067.680000] omap1-camera omap1-camera.0: omap1_cam_try_fmt: format 32315559 not found
> > [ 6068.480000] mplayer: page allocation failure. order:6, mode:0xd0
> > [ 6068.500000] Backtrace:
> > [ 6068.520000] [<c0028950>] (dump_backtrace+0x0/0x110) from [<c0028ea8>] (dump_stack+0x18/0x1c)
> > [ 6068.560000]  r6:00000006 r5:000000d0 r4:c1bcf000
> > [ 6068.590000] [<c0028e90>] (dump_stack+0x0/0x1c) from [<c0074e24>] (__alloc_pages_nodemask+0x504/0x560)
> > [ 6068.620000] [<c0074920>] (__alloc_pages_nodemask+0x0/0x560) from [<c002ae14>] (__dma_alloc+0x108/0x354)
> > [ 6068.660000] [<c002ad0c>] (__dma_alloc+0x0/0x354) from [<c002b0ec>] (dma_alloc_coherent+0x58/0x64)
> > [ 6068.700000] [<c002b094>] (dma_alloc_coherent+0x0/0x64) from [<bf000a44>] (__videobuf_mmap_mapper+0x10c/0x374 [videobuf_dma_contig])
> > [ 6068.740000]  r7:c16934c0 r6:00000000 r5:c171baec r4:00000000
> > [ 6068.770000] [<bf000938>] (__videobuf_mmap_mapper+0x0/0x374 [videobuf_dma_contig]) from [<c01f9a78>] (videobuf_mmap_mapper+0xc4/0x108)
> > [ 6068.810000] [<c01f99b4>] (videobuf_mmap_mapper+0x0/0x108) from [<c01fc1ac>] (soc_camera_mmap+0x80/0x140)
> > [ 6068.840000]  r5:c1a3b4e0 r4:00000000
> > [ 6068.870000] [<c01fc12c>] (soc_camera_mmap+0x0/0x140) from [<c01eeba8>] (v4l2_mmap+0x4c/0x5c)
> > [ 6068.900000]  r7:c145c000 r6:000000ff r5:c16934c0 r4:00000000
> > [ 6068.930000] [<c01eeb5c>] (v4l2_mmap+0x0/0x5c) from [<c0085de4>] (mmap_region+0x238/0x458)
> > [ 6068.970000] [<c0085bac>] (mmap_region+0x0/0x458) from [<c00862c0>] (do_mmap_pgoff+0x2bc/0x320)
> > [ 6069.000000] [<c0086004>] (do_mmap_pgoff+0x0/0x320) from [<c00863c0>] (sys_mmap_pgoff+0x9c/0xc8)
> > [ 6069.040000] [<c0086324>] (sys_mmap_pgoff+0x0/0xc8) from [<c0024f00>] (ret_fast_syscall+0x0/0x2c)
> > [ 6069.200000] Mem-info:
> > [ 6069.220000] Normal per-cpu:
> > [ 6069.240000] CPU    0: hi:    0, btch:   1 usd:   0
> > [ 6069.260000] active_anon:676 inactive_anon:682 isolated_anon:0
> > [ 6069.260000]  active_file:422 inactive_file:2348 isolated_file:0
> > [ 6069.260000]  unevictable:177 dirty:0 writeback:0 unstable:0
> > [ 6069.260000]  free:1166 slab_reclaimable:0 slab_unreclaimable:0
> > [ 6069.260000]  mapped:1120 shmem:0 pagetables:121 bounce:0
> > [ 6069.350000] Normal free:4664kB min:720kB low:900kB high:1080kB active_anon:2704kB inactive_anon:2728kB active_file:1688kB inactive_file:9392kB unevictable:708kB isolated(anon):0kB isolated(file):0kB present:32512kB mlocked:0kB 
> > dirty:0kB writeback:0kB mapped:4480kB shmem:0kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:552kB pagetables:484kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no
> > [ 6069.460000] lowmem_reserve[]: 0 0
> > [ 6069.470000] Normal: 6*4kB 20*8kB 14*16kB 29*32kB 26*64kB 9*128kB 2*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 4664kB
> > [ 6069.530000] 2960 total pagecache pages
> > [ 6069.550000] 8192 pages of RAM
> > [ 6069.560000] 1322 free pages
> > [ 6069.580000] 1114 reserved pages
> > [ 6069.590000] 750 slab pages
> > [ 6069.610000] 2476 pages shared
> > [ 6069.630000] 0 pages swap cached
> > [ 6069.640000] omap1-camera omap1-camera.0: dma_alloc_coherent size 204800 failed
> > [ 6069.680000] omap1-camera omap1-camera.0: OMAP1 Camera driver detached from camera 0
> > 
> > Maybe I should preallocate a few more pages than will be actually used by the 
> > driver?
> > 
> > Anyways, I'm not sure if this piece of code could be accepted for inclusion 
> > into the mainline tree, perhaps only under drivers/staging.
> > 
> > Thanks,
> > Janusz
> > 
> 
> ---
> Guennadi Liakhovetski, Ph.D.
> Freelance Open-Source Software Developer
> http://www.open-technology.de/
> --
> To unsubscribe from this list: send the line "unsubscribe linux-media" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

Re: [RFC] [PATCH 1/6] SoC Camera: add driver for OMAP1 camera interface

[Janusz Krzysztofik]

Monday 16 August 2010 12:17:36 Marin Mitov wrote:
> On Saturday, August 14, 2010 08:33:09 pm Guennadi Liakhovetski wrote:
> > On Fri, 13 Aug 2010, Janusz Krzysztofik wrote:
> > > Friday 13 August 2010 11:11:52 Marin Mitov napisał(a):
> > > > On Friday, August 13, 2010 11:52:41 am Guennadi Liakhovetski wrote:
> > > > > On Fri, 13 Aug 2010, Janusz Krzysztofik wrote:
> > > > > > Thursday 12 August 2010 23:38:17 Guennadi Liakhovetski napisał(a):
> > > > > > > 1. We've discussed this dynamic switching a bit on IRC today.
> > > > > > > The first reaction was - you probably should concentrate on
> > > > > > > getting the contiguous version to work reliably. I.e., to
> > > > > > > reserve the memory in the board init code similar, how other
> > > > > > > contig users currently do it.
> > > > > >
> > > > > > I already tried before to find out how I could allocate memory at
> > > > > > init without reinventing a new videobuf-dma-contig
> > > > > > implementation. Since in the Documentation/video4linux/videobuf
> > > > > > I've read that videobuf does not currently play well with drivers
> > > > > > that play tricks by allocating DMA space at system boot time,
> > > > > > I've implemented the alternate sg path.
> > > > > >
> > > > > > If it's not quite true what the documentation says and you can
> > > > > > give me a hint how this could be done, I might try again.
> > > > >
> > > > > For an example look at
> > > > > arch/arm/mach-mx3/mach-pcm037.c::pcm037_camera_alloc_dma().
> > >
> > > Yes, this is the solution that suffers from the already discussed
> > > limitation of not being able to remap a memory with different
> > > attributes, which affects OMAP1 as well.
> > >
> > > > For preallocating dma-coherent memory for device personal use during
> > > > device probe() time (when the memory is less fragmented compared to
> > > > open() time) see also dt3155_alloc_coherent/dt3155_free_coherent in
> > > > drivers/staging/dt3155v4l/dt3155vfl.c (for x86 arch, I do not know if
> > > > it works for arm arch)
> > >
> > > With this workaround applied, I get much better results, thank you
> > > Marin. However, it seems not bullet proof, since mmap still happens to
> > > fail for a reason not quite clear to me:
> >
> > What exactly does this mean - happens to fail - you mean starting and
> > stopping mplayer several times? Can you verify, that you're not leaking
> > memory? That you're freeing all allocated DMA memory again? Are you using
> > the same parameters to mplayer, right?
> >
> > As for the work-around - can you not do this in your board late-initcall
> > function?
> >
> > Not sure whether and how one can get this in the mainline. This is in
> > principle the same, as in the above dma_declare_coherent_memory()
> > example, only open-coded without the ioremap.
>
> My believe is that dma_declare_coherent_memory() could be used if your
> frame grabber has local RAM buffer (like video buffer if the graphic
> adapters) defined by BAR - that is why you need ioremap(). If this RAM
> turns out to be coherent you use dma_declare_coherent_memory() and any
> further invocation of dma_alloc_coherent() will allocate from it (till it
> is exosted). My use of dt3155_alloc_coherent()/dt3155_free_coherent() is to
> allocate a block of coherent 4MB memory during driver probe() method and
> use it latter (via videobuff_dma_contig framework)).
>
> > Maybe we can add a suitable function
> > to the dma-alloc API...
>
> Could be of general use, I am thinking about this. This could be done by
> just renaming dt3155_alloc_coherent()/dt3155_free_coherent() to something
> acceptable (dma_reserve_coherent_memory()/dma_release_reserved_memory(), I
> am open for suggestions) and export them. Should be added to
> drivers/base/dma-coherent.c.

Hi Marin,
Since I've finaly managed to make use of your method without any previously 
observerd limitations (see below), I'm interested in it being implemented 
system-wide. Are you going to submit a patch?

I would suggest creating one common function that allocates and fills the 
dev->dma_mem structure, and two wrappers that call it: a 
dma_declare_coherent_memory() replacement, that passes an ioremapped device 
memory address to the common fuction, and your proposed 
dma_reserve_coherent_memory(), that passes a pointer returned by the 
dma_alloc_coherent() instead.

> > > [ 6067.220000] omap1-camera omap1-camera.0: OMAP1 Camera driver attached to camera 0 
> > > [ 6067.650000] omap1-camera omap1-camera.0: omap1_cam_try_fmt: format 32315659 not found 
> > > [ 6067.680000] omap1-camera omap1-camera.0: omap1_cam_try_fmt: format 32315559 not found 
> > > [ 6068.480000] mplayer: page allocation failure. order:6, mode:0xd0 
> > > [ 6068.500000] Backtrace: 
> > > [ 6068.520000] [<c0028950>] (dump_backtrace+0x0/0x110) from [<c0028ea8>] (dump_stack+0x18/0x1c) 
> > > [ 6068.560000]  r6:00000006 r5:000000d0 r4:c1bcf000
> > > [ 6068.590000] [<c0028e90>] (dump_stack+0x0/0x1c) from [<c0074e24>] (__alloc_pages_nodemask+0x504/0x560) 
> > > [ 6068.620000] [<c0074920>] (__alloc_pages_nodemask+0x0/0x560) from [<c002ae14>] (__dma_alloc+0x108/0x354) 
> > > [ 6068.660000] [<c002ad0c>] (__dma_alloc+0x0/0x354) from [<c002b0ec>] (dma_alloc_coherent+0x58/0x64) 
> > > [ 6068.700000] [<c002b094>] (dma_alloc_coherent+0x0/0x64) from [<bf000a44>] (__videobuf_mmap_mapper+0x10c/0x374 [videobuf_dma_contig]) 
> > > [ 6068.740000]  r7:c16934c0 r6:00000000 r5:c171baec r4:00000000 
> > > [ 6068.770000] [<bf000938>] (__videobuf_mmap_mapper+0x0/0x374 [videobuf_dma_contig]) from [<c01f9a78>] (videobuf_mmap_mapper+0xc4/0x108) 
> > > [ 6068.810000] [<c01f99b4>] (videobuf_mmap_mapper+0x0/0x108) from [<c01fc1ac>] (soc_camera_mmap+0x80/0x140) 
> > > [ 6068.840000]  r5:c1a3b4e0 r4:00000000 
> > > [ 6068.870000] [<c01fc12c>] (soc_camera_mmap+0x0/0x140) from [<c01eeba8>] (v4l2_mmap+0x4c/0x5c) 
> > > [ 6068.900000]  r7:c145c000 r6:000000ff r5:c16934c0 r4:00000000 
> > > [ 6068.930000] [<c01eeb5c>] (v4l2_mmap+0x0/0x5c) from [<c0085de4>] (mmap_region+0x238/0x458) 
> > > [ 6068.970000] [<c0085bac>] (mmap_region+0x0/0x458) from [<c00862c0>] (do_mmap_pgoff+0x2bc/0x320) 
> > > [ 6069.000000] [<c0086004>] (do_mmap_pgoff+0x0/0x320) from [<c00863c0>] (sys_mmap_pgoff+0x9c/0xc8) 
> > > [ 6069.040000] [<c0086324>] (sys_mmap_pgoff+0x0/0xc8) from [<c0024f00>] (ret_fast_syscall+0x0/0x2c) 
> > > [ 6069.200000] Mem-info: 
> > > [ 6069.220000] Normal per-cpu: 
> > > [ 6069.240000] CPU    0: hi:    0, btch:   1 usd:   0
> > > [ 6069.260000] active_anon:676 inactive_anon:682 isolated_anon:0
> > > [ 6069.260000]  active_file:422 inactive_file:2348 isolated_file:0
> > > [ 6069.260000]  unevictable:177 dirty:0 writeback:0 unstable:0
> > > [ 6069.260000]  free:1166 slab_reclaimable:0 slab_unreclaimable:0
> > > [ 6069.260000]  mapped:1120 shmem:0 pagetables:121 bounce:0
> > > [ 6069.350000] Normal free:4664kB min:720kB low:900kB high:1080kB active_anon:2704kB inactive_anon:2728kB active_file:1688kB inactive_file:9392kB unevictable:708kB isolated(anon):0kB isolated(file):0kB present:32512kB mlocked:0kB 
dirty:0kB writeback:0kB mapped:4480kB shmem:0kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:552kB pagetables:484kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no 
> > > [ 6069.460000] lowmem_reserve[]: 0 0
> > > [ 6069.470000] Normal: 6*4kB 20*8kB 14*16kB 29*32kB 26*64kB 9*128kB 2*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 4664kB [ 6069.530000] 2960 total pagecache pages
> > > [ 6069.550000] 8192 pages of RAM
> > > [ 6069.560000] 1322 free pages
> > > [ 6069.580000] 1114 reserved pages
> > > [ 6069.590000] 750 slab pages
> > > [ 6069.610000] 2476 pages shared
> > > [ 6069.630000] 0 pages swap cached
> > > [ 6069.640000] omap1-camera omap1-camera.0: dma_alloc_coherent size 204800 failed 
> > > [ 6069.680000] omap1-camera omap1-camera.0: OMAP1 Camera driver detached from camera 0
> > >
> > > Maybe I should preallocate a few more pages than will be actually used
> > > by the driver?

That was it. I was trying to reserve exact frame size, times number of buffers. 
Apparently, the frame size should be rounded up to the nearest power of 2 
first for it to work as expected.

Thanks,
Janusz

Re: [RFC] [PATCH 1/6] SoC Camera: add driver for OMAP1 camera interface

[Guennadi Liakhovetski]

On Thu, 19 Aug 2010, Janusz Krzysztofik wrote:

> Hi Marin,
> Since I've finaly managed to make use of your method without any previously 
> observerd limitations (see below), I'm interested in it being implemented 
> system-wide. Are you going to submit a patch?

I'm about to submit a patch, which you'll be most welcome to test. Just 
give me a couple more hours.

> I would suggest creating one common function that allocates and fills the 
> dev->dma_mem structure, and two wrappers that call it: a 
> dma_declare_coherent_memory() replacement, that passes an ioremapped device 
> memory address to the common fuction, and your proposed 
> dma_reserve_coherent_memory(), that passes a pointer returned by the 
> dma_alloc_coherent() instead.
> 
> > > > [ 6067.220000] omap1-camera omap1-camera.0: OMAP1 Camera driver attached to camera 0 
> > > > [ 6067.650000] omap1-camera omap1-camera.0: omap1_cam_try_fmt: format 32315659 not found 
> > > > [ 6067.680000] omap1-camera omap1-camera.0: omap1_cam_try_fmt: format 32315559 not found 
> > > > [ 6068.480000] mplayer: page allocation failure. order:6, mode:0xd0 
> > > > [ 6068.500000] Backtrace: 
> > > > [ 6068.520000] [<c0028950>] (dump_backtrace+0x0/0x110) from [<c0028ea8>] (dump_stack+0x18/0x1c) 
> > > > [ 6068.560000]  r6:00000006 r5:000000d0 r4:c1bcf000
> > > > [ 6068.590000] [<c0028e90>] (dump_stack+0x0/0x1c) from [<c0074e24>] (__alloc_pages_nodemask+0x504/0x560) 
> > > > [ 6068.620000] [<c0074920>] (__alloc_pages_nodemask+0x0/0x560) from [<c002ae14>] (__dma_alloc+0x108/0x354) 
> > > > [ 6068.660000] [<c002ad0c>] (__dma_alloc+0x0/0x354) from [<c002b0ec>] (dma_alloc_coherent+0x58/0x64) 
> > > > [ 6068.700000] [<c002b094>] (dma_alloc_coherent+0x0/0x64) from [<bf000a44>] (__videobuf_mmap_mapper+0x10c/0x374 [videobuf_dma_contig]) 
> > > > [ 6068.740000]  r7:c16934c0 r6:00000000 r5:c171baec r4:00000000 
> > > > [ 6068.770000] [<bf000938>] (__videobuf_mmap_mapper+0x0/0x374 [videobuf_dma_contig]) from [<c01f9a78>] (videobuf_mmap_mapper+0xc4/0x108) 
> > > > [ 6068.810000] [<c01f99b4>] (videobuf_mmap_mapper+0x0/0x108) from [<c01fc1ac>] (soc_camera_mmap+0x80/0x140) 
> > > > [ 6068.840000]  r5:c1a3b4e0 r4:00000000 
> > > > [ 6068.870000] [<c01fc12c>] (soc_camera_mmap+0x0/0x140) from [<c01eeba8>] (v4l2_mmap+0x4c/0x5c) 
> > > > [ 6068.900000]  r7:c145c000 r6:000000ff r5:c16934c0 r4:00000000 
> > > > [ 6068.930000] [<c01eeb5c>] (v4l2_mmap+0x0/0x5c) from [<c0085de4>] (mmap_region+0x238/0x458) 
> > > > [ 6068.970000] [<c0085bac>] (mmap_region+0x0/0x458) from [<c00862c0>] (do_mmap_pgoff+0x2bc/0x320) 
> > > > [ 6069.000000] [<c0086004>] (do_mmap_pgoff+0x0/0x320) from [<c00863c0>] (sys_mmap_pgoff+0x9c/0xc8) 
> > > > [ 6069.040000] [<c0086324>] (sys_mmap_pgoff+0x0/0xc8) from [<c0024f00>] (ret_fast_syscall+0x0/0x2c) 
> > > > [ 6069.200000] Mem-info: 
> > > > [ 6069.220000] Normal per-cpu: 
> > > > [ 6069.240000] CPU    0: hi:    0, btch:   1 usd:   0
> > > > [ 6069.260000] active_anon:676 inactive_anon:682 isolated_anon:0
> > > > [ 6069.260000]  active_file:422 inactive_file:2348 isolated_file:0
> > > > [ 6069.260000]  unevictable:177 dirty:0 writeback:0 unstable:0
> > > > [ 6069.260000]  free:1166 slab_reclaimable:0 slab_unreclaimable:0
> > > > [ 6069.260000]  mapped:1120 shmem:0 pagetables:121 bounce:0
> > > > [ 6069.350000] Normal free:4664kB min:720kB low:900kB high:1080kB active_anon:2704kB inactive_anon:2728kB active_file:1688kB inactive_file:9392kB unevictable:708kB isolated(anon):0kB isolated(file):0kB present:32512kB mlocked:0kB 
> dirty:0kB writeback:0kB mapped:4480kB shmem:0kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:552kB pagetables:484kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no 
> > > > [ 6069.460000] lowmem_reserve[]: 0 0
> > > > [ 6069.470000] Normal: 6*4kB 20*8kB 14*16kB 29*32kB 26*64kB 9*128kB 2*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 4664kB [ 6069.530000] 2960 total pagecache pages
> > > > [ 6069.550000] 8192 pages of RAM
> > > > [ 6069.560000] 1322 free pages
> > > > [ 6069.580000] 1114 reserved pages
> > > > [ 6069.590000] 750 slab pages
> > > > [ 6069.610000] 2476 pages shared
> > > > [ 6069.630000] 0 pages swap cached
> > > > [ 6069.640000] omap1-camera omap1-camera.0: dma_alloc_coherent size 204800 failed 
> > > > [ 6069.680000] omap1-camera omap1-camera.0: OMAP1 Camera driver detached from camera 0
> > > >
> > > > Maybe I should preallocate a few more pages than will be actually used
> > > > by the driver?
> 
> That was it. I was trying to reserve exact frame size, times number of buffers. 
> Apparently, the frame size should be rounded up to the nearest power of 2 
> first for it to work as expected.

No, I don't think you should go to the next power of 2 - that's too crude. 
Try rounding your buffer size to the page size, that should suffice.

Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/

Re: [RFC] [PATCH 1/6] SoC Camera: add driver for OMAP1 camera interface

[Marin Mitov]

On Thursday, August 19, 2010 02:39:47 pm Guennadi Liakhovetski wrote:
> On Thu, 19 Aug 2010, Janusz Krzysztofik wrote:
> 
> > Hi Marin,
> > Since I've finaly managed to make use of your method without any previously 
> > observerd limitations (see below), I'm interested in it being implemented 
> > system-wide. Are you going to submit a patch?

It is ready, I just wait for the invitation.

Marin Mitov

> 
> I'm about to submit a patch, which you'll be most welcome to test. Just 
> give me a couple more hours.
> 
> > I would suggest creating one common function that allocates and fills the 
> > dev->dma_mem structure, and two wrappers that call it: a 
> > dma_declare_coherent_memory() replacement, that passes an ioremapped device 
> > memory address to the common fuction, and your proposed 
> > dma_reserve_coherent_memory(), that passes a pointer returned by the 
> > dma_alloc_coherent() instead.

> No, I don't think you should go to the next power of 2 - that's too crude. 
> Try rounding your buffer size to the page size, that should suffice.

Allocated coherent memory is always a power of 2.
Thanks.

Marin Mitov

> 
> Thanks
> Guennadi
> ---
> Guennadi Liakhovetski, Ph.D.
> Freelance Open-Source Software Developer
> http://www.open-technology.de/
> 

Re: [RFC] [PATCH 1/6] SoC Camera: add driver for OMAP1 camera interface

[Janusz Krzysztofik]

Thursday 19 August 2010 14:16:21 Marin Mitov napisał(a):
> On Thursday, August 19, 2010 02:39:47 pm Guennadi Liakhovetski wrote:
> >
> > No, I don't think you should go to the next power of 2 - that's too
> > crude. Try rounding your buffer size to the page size, that should
> > suffice.

Guennadi,
If you have a look at how a device reserved memory is next allocated to a 
driver with drivers/base/dma-coherent.c::dma_alloc_from_coherent(), then than 
you may find my conclusion on a power of 2 as true:

int dma_alloc_from_coherent(struct device *dev, ssize_t size,
					dma_addr_t *dma_handle, void **ret)
{
...
        int order = get_order(size);
...
	pageno = bitmap_find_free_region(mem->bitmap, mem->size, order);
...
}


> Allocated coherent memory is always a power of 2.

Marin,
For ARM, this seems true as long as allocated with the above from a device 
assigned pool, but not true for a (pre)allocation from a generic system RAM. 
See arch/arm/mm/dma-mapping.c::__dma_alloc_buffer(), where it looks like extra 
pages are freed:

static struct page *__dma_alloc_buffer(struct device *dev, size_t size, gfp_t gfp)
{
	unsigned long order = get_order(size);
...
	page = alloc_pages(gfp, order);
...
	split_page(page, order);
        for (p = page + (size >> PAGE_SHIFT), e = page + (1 << order); p < e; p++)
                __free_page(p);
...
}	


Thanks,
Janusz

Re: [RFC] [PATCH 1/6] SoC Camera: add driver for OMAP1 camera interface

[Marin Mitov]

On Thursday, August 19, 2010 08:09:27 pm Janusz Krzysztofik wrote:
> Thursday 19 August 2010 14:16:21 Marin Mitov napisał(a):
> > On Thursday, August 19, 2010 02:39:47 pm Guennadi Liakhovetski wrote:
> > >
> > > No, I don't think you should go to the next power of 2 - that's too
> > > crude. Try rounding your buffer size to the page size, that should
> > > suffice.
> 
> Guennadi,
> If you have a look at how a device reserved memory is next allocated to a 
> driver with drivers/base/dma-coherent.c::dma_alloc_from_coherent(), then than 
> you may find my conclusion on a power of 2 as true:
> 
> int dma_alloc_from_coherent(struct device *dev, ssize_t size,
> 					dma_addr_t *dma_handle, void **ret)
> {
> ...
>         int order = get_order(size);
> ...
> 	pageno = bitmap_find_free_region(mem->bitmap, mem->size, order);
> ...
> }
> 
> 
> > Allocated coherent memory is always a power of 2.
> 
> Marin,
> For ARM, this seems true as long as allocated with the above from a device 
> assigned pool, but not true for a (pre)allocation from a generic system RAM. 
> See arch/arm/mm/dma-mapping.c::__dma_alloc_buffer(), where it looks like extra 
> pages are freed:
> 
> static struct page *__dma_alloc_buffer(struct device *dev, size_t size, gfp_t gfp)
> {
> 	unsigned long order = get_order(size);
> ...
> 	page = alloc_pages(gfp, order);
> ...
> 	split_page(page, order);
>         for (p = page + (size >> PAGE_SHIFT), e = page + (1 << order); p < e; p++)
>                 __free_page(p);
> ...
> }	

Thanks for the clarification.

Marin Mitov

> 
> 
> Thanks,
> Janusz
> 

[RFC] [PATCH 2/6] OMAP1: Add support for SoC camera interface

[Janusz Krzysztofik]

This patch adds support for SoC camera interface to OMAP1 devices.

Created and tested against linux-2.6.35-rc3 on Amstrad Delta.

For successfull compilation, requires a header file provided by PATCH 1/6 from 
this series, "SoC Camera: add driver for OMAP1 camera interface".

Signed-off-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
---
 arch/arm/mach-omap1/devices.c             |   43 ++++++++++++++++++++++++++++++
 arch/arm/mach-omap1/include/mach/camera.h |    8 +++++
 2 files changed, 51 insertions(+)

--- linux-2.6.35-rc3.orig/arch/arm/mach-omap1/devices.c	2010-06-26 15:54:47.000000000 +0200
+++ linux-2.6.35-rc3/arch/arm/mach-omap1/devices.c	2010-07-18 01:54:39.000000000 +0200
@@ -15,6 +15,7 @@
 #include <linux/platform_device.h>
 #include <linux/io.h>
 #include <linux/spi/spi.h>
+#include <linux/dma-mapping.h>
 
 #include <mach/hardware.h>
 #include <asm/mach/map.h>
@@ -25,6 +26,7 @@
 #include <mach/gpio.h>
 #include <plat/mmc.h>
 #include <plat/omap7xx.h>
+#include <mach/camera.h>
 
 /*-------------------------------------------------------------------------*/
 
@@ -267,6 +269,47 @@ static inline void omap_init_sti(void)
 static inline void omap_init_sti(void) {}
 #endif
 
+
+#define OMAP1_CAMERA_BASE	0xfffb6800
+
+static struct resource omap1_camera_resources[] = {
+	[0] = {
+		.start	= OMAP1_CAMERA_BASE,
+		.end	= OMAP1_CAMERA_BASE + OMAP1_CAMERA_IOSIZE - 1,
+		.flags	= IORESOURCE_MEM,
+	},
+	[1] = {
+		.start	= INT_CAMERA,
+		.flags	= IORESOURCE_IRQ,
+	},
+};
+
+static u64 omap1_camera_dma_mask = DMA_BIT_MASK(32);
+
+static struct platform_device omap1_camera_device = {
+	.name		= "omap1-camera",
+	.id		= 0, /* This is used to put cameras on this interface */
+	.dev		= {
+		.dma_mask		= &omap1_camera_dma_mask,
+		.coherent_dma_mask	= DMA_BIT_MASK(32),
+	},
+	.num_resources	= ARRAY_SIZE(omap1_camera_resources),
+	.resource	= omap1_camera_resources,
+};
+
+void __init omap1_set_camera_info(struct omap1_cam_platform_data *info)
+{
+	struct platform_device *dev = &omap1_camera_device;
+	int ret;
+
+	dev->dev.platform_data = info;
+
+	ret = platform_device_register(dev);
+	if (ret)
+		dev_err(&dev->dev, "unable to register device: %d\n", ret);
+}
+
+
 /*-------------------------------------------------------------------------*/
 
 /*
--- linux-2.6.35-rc3.orig/arch/arm/mach-omap1/include/mach/camera.h	1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.35-rc3/arch/arm/mach-omap1/include/mach/camera.h	2010-07-18 01:57:18.000000000 +0200
@@ -0,0 +1,8 @@
+#ifndef __ASM_ARCH_CAMERA_H_
+#define __ASM_ARCH_CAMERA_H_
+
+#include <media/omap1_camera.h>
+
+extern void omap1_set_camera_info(struct omap1_cam_platform_data *);
+
+#endif /* __ASM_ARCH_CAMERA_H_ */

[RFC] [PATCH 3/6] SoC Camera: add driver for OV6650 sensor

[Janusz Krzysztofik]

This patch provides a V4L2 SoC Camera driver for OV6650 camera sensor, found 
on OMAP1 SoC based Amstrad Delta videophone.

Since I have no experience with camera sensors, and the sensor documentation I 
was able to find was not very comprehensive, I left most settings at their 
default (reset) values, except for:
- those required for proper mediabus parameters and picture format setup,
- those used by controls.
Resulting picture quality is far from perfect, but better than nothing.

In order to be able to get / set the sensor frame rate from userspace, I 
decided to provide two not yet SoC camera supported operations, g_parm and 
s_parm. These can be used after applying patch 4/6 from this series, 
"SoC Camera: add support for g_parm / s_parm operations".

Created and tested against linux-2.6.35-rc3 on Amstrad Delta.

Signed-off-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
---
 drivers/media/video/Kconfig     |    6
 drivers/media/video/Makefile    |    1
 drivers/media/video/ov6650.c    | 1336 ++++++++++++++++++++++++++++++++++++++++
 include/media/v4l2-chip-ident.h |    1
 4 files changed, 1344 insertions(+)

--- linux-2.6.35-rc3.orig/drivers/media/video/Kconfig	2010-06-26 15:55:29.000000000 +0200
+++ linux-2.6.35-rc3/drivers/media/video/Kconfig	2010-07-02 04:12:02.000000000 +0200
@@ -913,6 +913,12 @@ config SOC_CAMERA_PLATFORM
 	help
 	  This is a generic SoC camera platform driver, useful for testing
 
+config SOC_CAMERA_OV6650
+	tristate "ov6650 sensor support"
+	depends on SOC_CAMERA && I2C
+	help
+	  This is a V4L2 SoC camera driver for the OmniVision OV6650 sensor
+
 config SOC_CAMERA_OV772X
 	tristate "ov772x camera support"
 	depends on SOC_CAMERA && I2C
--- linux-2.6.35-rc3.orig/drivers/media/video/Makefile	2010-06-26 15:55:29.000000000 +0200
+++ linux-2.6.35-rc3/drivers/media/video/Makefile	2010-06-26 17:28:09.000000000 +0200
@@ -79,6 +79,7 @@ obj-$(CONFIG_SOC_CAMERA_MT9M111)	+= mt9m
 obj-$(CONFIG_SOC_CAMERA_MT9T031)	+= mt9t031.o
 obj-$(CONFIG_SOC_CAMERA_MT9T112)	+= mt9t112.o
 obj-$(CONFIG_SOC_CAMERA_MT9V022)	+= mt9v022.o
+obj-$(CONFIG_SOC_CAMERA_OV6650)		+= ov6650.o
 obj-$(CONFIG_SOC_CAMERA_OV772X)		+= ov772x.o
 obj-$(CONFIG_SOC_CAMERA_OV9640)		+= ov9640.o
 obj-$(CONFIG_SOC_CAMERA_RJ54N1)		+= rj54n1cb0c.o
--- linux-2.6.35-rc3.orig/drivers/media/video/ov6650.c	1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.35-rc3/drivers/media/video/ov6650.c	2010-07-18 02:06:22.000000000 +0200
@@ -0,0 +1,1336 @@
+/*
+ * V4L2 SoC Camera driver for OmniVision OV6650 Camera Sensor
+ *
+ * Copyright (C) 2010 Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
+ *
+ * Based on OmniVision OV96xx Camera Driver
+ * Copyright (C) 2009 Marek Vasut <marek.vasut@gmail.com>
+ *
+ * Based on ov772x camera driver:
+ * Copyright (C) 2008 Renesas Solutions Corp.
+ * Kuninori Morimoto <morimoto.kuninori@renesas.com>
+ *
+ * Based on ov7670 and soc_camera_platform driver,
+ * Copyright 2006-7 Jonathan Corbet <corbet@lwn.net>
+ * Copyright (C) 2008 Magnus Damm
+ * Copyright (C) 2008, Guennadi Liakhovetski <kernel@pengutronix.de>
+ *
+ * Hardware specific bits initialy based on former work by Matt Callow
+ * drivers/media/video/omap/sensor_ov6650.c
+ * Copyright (C) 2006 Matt Callow
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <media/v4l2-chip-ident.h>
+#include <media/soc_camera.h>
+
+
+/* Register definitions */
+#define	REG_GAIN		0x00	/* range 00 - 3F */
+#define	REG_BLUE		0x01
+#define	REG_RED			0x02
+#define	REG_SAT			0x03	/* [7:4] saturation [0:3] reserved */
+#define	REG_HUE			0x04	/* [7:6] rsrvd [5] hue en [4:0] hue */
+
+#define	REG_BRT			0x06
+
+#define	REG_PIDH		0x0a
+#define	REG_PIDL		0x0b
+
+#define	REG_AECH		0x10
+#define	REG_CLKRC		0x11	/* Data Format and Internal Clock */
+					/* [7:6] Input system clock (MHz)*/
+					/*   00=8, 01=12, 10=16, 11=24 */
+					/* [5:0]: Internal Clock Pre-Scaler */
+#define	REG_COMA		0x12	/* [7] Reset */
+#define	REG_COMB		0x13
+#define	REG_COMC		0x14
+#define	REG_COMD		0x15
+#define REG_COML		0x16
+#define	REG_HSTRT		0x17
+#define	REG_HSTOP		0x18
+#define	REG_VSTRT		0x19
+#define	REG_VSTOP		0x1a
+#define	REG_PSHFT		0x1b
+#define	REG_MIDH		0x1c
+#define	REG_MIDL		0x1d
+#define	REG_HSYNS		0x1e
+#define	REG_HSYNE		0x1f
+#define	REG_COME		0x20
+#define	REG_YOFF		0x21
+#define	REG_UOFF		0x22
+#define	REG_VOFF		0x23
+#define	REG_AEW			0x24
+#define	REG_AEB			0x25
+#define	REG_COMF		0x26
+#define	REG_COMG		0x27
+#define	REG_COMH		0x28
+#define REG_COMI		0x29
+
+#define	REG_FRARL		0x2b
+#define	REG_COMJ		0x2c
+#define	REG_COMK		0x2d
+#define	REG_AVGY		0x2e
+#define	REG_REF0		0x2f
+#define	REG_REF1		0x30
+#define	REG_REF2		0x31
+#define	REG_FRAJH		0x32
+#define	REG_FRAJL		0x33
+#define	REG_FACT		0x34
+#define REG_L1AEC		0x35
+#define REG_AVGU		0x36
+#define	REG_AVGV		0x37
+
+#define	REG_SPCB		0x60
+#define	REG_SPCC		0x61
+#define	REG_GAM1		0x62
+#define	REG_GAM2		0x63
+#define	REG_GAM3		0x64
+#define	REG_SPCD		0x65
+
+#define	REG_SPCE		0x68
+#define	REG_ADCL		0x69
+
+#define	REG_RMCO		0x6c
+#define	REG_GMCO		0x6d
+#define	REG_BMCO		0x6e
+
+#define NUM_REGS		(REG_BMCO + 1)
+
+
+/* Register bits, values, etc. */
+#define OV6650_PIDH		0x66	/* high byte of product ID number */
+#define OV6650_PIDL		0x50	/* low byte of product ID number */
+#define OV6650_MIDH		0x7F	/* high byte of mfg ID */
+#define OV6650_MIDL		0xA2	/* low byte of mfg ID */
+
+#define DEF_GAIN		0x00
+#define DEF_BLUE		0x80
+#define DEF_RED			0x80
+
+#define SAT_SHIFT		4
+#define SAT_MASK		0xf
+#define SET_SAT(x)		(((x) & SAT_MASK) << SAT_SHIFT)
+
+#define HUE_EN			BIT(5)
+#define HUE_MASK		0x1f
+#define DEF_HUE			0x10
+#define SET_HUE(x)		((x) == DEF_HUE ? (x) : \
+						HUE_EN | ((x) & HUE_MASK))
+
+#define DEF_AECH		0x4D
+
+#define	CLKRC_6MHz		0x00
+#define	CLKRC_12MHz		0x40
+#define	CLKRC_16MHz		0x80
+#define	CLKRC_24MHz		0xc0
+#define	CLKRC_DIV_MASK		0x3f
+#define	GET_CLKRC_DIV(x)	(((x) & CLKRC_DIV_MASK) + 1)
+
+#define COMA_RESET		BIT(7)
+#define COMA_QCIF		BIT(5)
+#define COMA_RAW_RGB		BIT(4)
+#define COMA_RGB		BIT(3)
+#define COMA_BW			BIT(2)
+#define COMA_WORD_SWAP		BIT(1)
+#define COMA_BYTE_SWAP		BIT(0)
+#define DEF_COMA		0x00
+
+#define	COMB_FLIP_V		BIT(7)
+#define	COMB_FLIP_H		BIT(5)
+#define COMB_AWB		BIT(2)
+#define COMB_AGC		BIT(1)
+#define COMB_AEC		BIT(0)
+
+#define COML_ONE_CHANNEL	BIT(7)
+
+#define DEF_HSTRT		0x24
+#define DEF_HSTOP		0xd4
+#define DEF_VSTRT		0x04
+#define DEF_VSTOP		0x94
+
+#define COMF_HREF_LOW		BIT(4)
+
+#define COMJ_PCLK_RISING	BIT(4)
+#define COMJ_VSYNC_HIGH		BIT(0)
+
+/* supported resolutions */
+#define W_QCIF			(DEF_HSTOP - DEF_HSTRT)
+#define W_CIF			(W_QCIF << 1)
+#define H_QCIF			(DEF_VSTOP - DEF_VSTRT)
+#define H_CIF			(H_QCIF << 1)
+
+#define FRAME_RATE_MAX		30
+
+
+struct ov6650_reg {
+	u8	reg;
+	u8	val;
+};
+
+struct ov6650 {
+	struct v4l2_subdev	subdev;
+
+	int			gain;
+	int			blue;
+	int			red;
+	int			saturation;
+	int			hue;
+	int			brightness;
+	int			exposure;
+	int			gamma;
+	bool			vflip;
+	bool			hflip;
+	bool			awb;
+	bool			agc;
+	int			aec;
+	bool			hue_auto;
+	bool			qcif;
+	unsigned long		pclk_max;	/* from resolution and format */
+	unsigned long		pclk_limit;	/* from host */
+	struct v4l2_fract	timeperframe;	/* as requested with s_parm */
+};
+
+
+/* default register setup */
+static const struct ov6650_reg ov6650_regs_dflt[] = {
+	{ REG_COMA,	DEF_COMA },	/* ~COMA_RESET */
+};
+
+static enum v4l2_mbus_pixelcode ov6650_codes[] = {
+	V4L2_MBUS_FMT_YUYV8_2X8_LE,
+	V4L2_MBUS_FMT_YUYV8_2X8_BE,
+	V4L2_MBUS_FMT_YVYU8_2X8_LE,
+	V4L2_MBUS_FMT_YVYU8_2X8_BE,
+	V4L2_MBUS_FMT_SBGGR8_1X8,
+	V4L2_MBUS_FMT_GREY8_1X8,
+};
+
+static const struct v4l2_queryctrl ov6650_controls[] = {
+	{
+		.id		= V4L2_CID_AUTOGAIN,
+		.type		= V4L2_CTRL_TYPE_BOOLEAN,
+		.name		= "AGC",
+		.minimum	= 0,
+		.maximum	= 1,
+		.step		= 1,
+		.default_value	= 1,
+	},
+	{
+		.id		= V4L2_CID_GAIN,
+		.type		= V4L2_CTRL_TYPE_INTEGER,
+		.name		= "Gain",
+		.minimum	= 0,
+		.maximum	= 0x3f,
+		.step		= 1,
+		.default_value	= DEF_GAIN,
+	},
+	{
+		.id		= V4L2_CID_AUTO_WHITE_BALANCE,
+		.type		= V4L2_CTRL_TYPE_BOOLEAN,
+		.name		= "AWB",
+		.minimum	= 0,
+		.maximum	= 1,
+		.step		= 1,
+		.default_value	= 1,
+	},
+	{
+		.id		= V4L2_CID_BLUE_BALANCE,
+		.type		= V4L2_CTRL_TYPE_INTEGER,
+		.name		= "Blue",
+		.minimum	= 0,
+		.maximum	= 0xff,
+		.step		= 1,
+		.default_value	= DEF_BLUE,
+	},
+	{
+		.id		= V4L2_CID_RED_BALANCE,
+		.type		= V4L2_CTRL_TYPE_INTEGER,
+		.name		= "Red",
+		.minimum	= 0,
+		.maximum	= 0xff,
+		.step		= 1,
+		.default_value	= DEF_RED,
+	},
+	{
+		.id		= V4L2_CID_SATURATION,
+		.type		= V4L2_CTRL_TYPE_INTEGER,
+		.name		= "Saturation",
+		.minimum	= 0,
+		.maximum	= 0xf,
+		.step		= 1,
+		.default_value	= 0x8,
+	},
+	{
+		.id		= V4L2_CID_HUE_AUTO,
+		.type		= V4L2_CTRL_TYPE_BOOLEAN,
+		.name		= "Auto Hue",
+		.minimum	= 0,
+		.maximum	= 1,
+		.step		= 1,
+		.default_value	= 1,
+	},
+	{
+		.id		= V4L2_CID_HUE,
+		.type		= V4L2_CTRL_TYPE_INTEGER,
+		.name		= "Hue",
+		.minimum	= 0,
+		.maximum	= 0x1f,
+		.step		= 1,
+		.default_value	= DEF_HUE,
+	},
+	{
+		.id		= V4L2_CID_BRIGHTNESS,
+		.type		= V4L2_CTRL_TYPE_INTEGER,
+		.name		= "Brightness",
+		.minimum	= 0,
+		.maximum	= 0xff,
+		.step		= 1,
+		.default_value	= 0x80,
+	},
+	{
+		.id		= V4L2_CID_EXPOSURE_AUTO,
+		.type		= V4L2_CTRL_TYPE_INTEGER,
+		.name		= "AEC",
+		.minimum	= 0,
+		.maximum	= 3,
+		.step		= 1,
+		.default_value	= 0,
+	},
+	{
+		.id		= V4L2_CID_EXPOSURE,
+		.type		= V4L2_CTRL_TYPE_INTEGER,
+		.name		= "Exposure",
+		.minimum	= 0,
+		.maximum	= 0xff,
+		.step		= 1,
+		.default_value	= DEF_AECH,
+	},
+	{
+		.id		= V4L2_CID_GAMMA,
+		.type		= V4L2_CTRL_TYPE_INTEGER,
+		.name		= "Gamma",
+		.minimum	= 0,
+		.maximum	= 0xff,
+		.step		= 1,
+		.default_value	= 0x12,
+	},
+	{
+		.id		= V4L2_CID_VFLIP,
+		.type		= V4L2_CTRL_TYPE_BOOLEAN,
+		.name		= "Flip Vertically",
+		.minimum	= 0,
+		.maximum	= 1,
+		.step		= 1,
+		.default_value	= 0,
+	},
+	{
+		.id		= V4L2_CID_HFLIP,
+		.type		= V4L2_CTRL_TYPE_BOOLEAN,
+		.name		= "Flip Horizontally",
+		.minimum	= 0,
+		.maximum	= 1,
+		.step		= 1,
+		.default_value	= 0,
+	},
+};
+
+/* read a register */
+static int ov6650_reg_read(struct i2c_client *client, u8 reg, u8 *val)
+{
+	int ret;
+	u8 data = reg;
+	struct i2c_msg msg = {
+		.addr	= client->addr,
+		.flags	= 0,
+		.len	= 1,
+		.buf	= &data,
+	};
+
+	ret = i2c_transfer(client->adapter, &msg, 1);
+	if (ret < 0)
+		goto err;
+
+	msg.flags = I2C_M_RD;
+	ret = i2c_transfer(client->adapter, &msg, 1);
+	if (ret < 0)
+		goto err;
+
+	*val = data;
+	return 0;
+
+err:
+	dev_err(&client->dev, "Failed reading register 0x%02x!\n", reg);
+	return ret;
+}
+
+/* write a register */
+static int ov6650_reg_write(struct i2c_client *client, u8 reg, u8 val)
+{
+	int ret;
+	u8 _val;
+	unsigned char data[2] = { reg, val };
+	struct i2c_msg msg = {
+		.addr	= client->addr,
+		.flags	= 0,
+		.len	= 2,
+		.buf	= data,
+	};
+
+	ret = i2c_transfer(client->adapter, &msg, 1);
+	if (ret < 0) {
+		dev_err(&client->dev, "Failed writing register 0x%02x!\n", reg);
+		return ret;
+	}
+	msleep(1);
+
+	/* we have to read the register back ... no idea why, maybe HW bug */
+	ret = ov6650_reg_read(client, reg, &_val);
+	if (ret)
+		dev_err(&client->dev,
+			"Failed reading back register 0x%02x!\n", reg);
+
+	return 0;
+}
+
+
+/* Read a register, alter its bits, write it back */
+static int ov6650_reg_rmw(struct i2c_client *client, u8 reg, u8 set, u8 mask)
+{
+	u8 val;
+	int ret;
+
+	ret = ov6650_reg_read(client, reg, &val);
+	if (ret) {
+		dev_err(&client->dev,
+			"[Read]-Modify-Write of register %02x failed!\n", reg);
+		return val;
+	}
+
+	val &= ~mask;
+	val |= set;
+
+	ret = ov6650_reg_write(client, reg, val);
+	if (ret)
+		dev_err(&client->dev,
+			"Read-Modify-[Write] of register %02x failed!\n", reg);
+
+	return ret;
+}
+
+/* Soft reset the camera. This has nothing to do with the RESET pin! */
+static int ov6650_reset(struct i2c_client *client)
+{
+	int ret;
+
+	dev_dbg(&client->dev, "reset\n");
+
+	ret = ov6650_reg_rmw(client, REG_COMA, COMA_RESET, 0);
+	if (ret)
+		dev_err(&client->dev,
+			"An error occured while entering soft reset!\n");
+
+	return ret;
+}
+
+static struct ov6650 *to_ov6650(const struct i2c_client *client)
+{
+	return container_of(i2c_get_clientdata(client), struct ov6650, subdev);
+}
+
+/* Start/Stop streaming from the device */
+static int ov6650_s_stream(struct v4l2_subdev *sd, int enable)
+{
+	return 0;
+}
+
+/* Alter bus settings on camera side */
+static int ov6650_set_bus_param(struct soc_camera_device *icd,
+				unsigned long flags)
+{
+	struct soc_camera_link *icl = to_soc_camera_link(icd);
+	struct i2c_client *client = to_i2c_client(to_soc_camera_control(icd));
+	int ret;
+
+	flags = soc_camera_apply_sensor_flags(icl, flags);
+
+	if (flags & SOCAM_PCLK_SAMPLE_RISING)
+		ret = ov6650_reg_rmw(client, REG_COMJ, COMJ_PCLK_RISING, 0);
+	else
+		ret = ov6650_reg_rmw(client, REG_COMJ, 0, COMJ_PCLK_RISING);
+	if (ret)
+		goto out;
+
+	if (flags & SOCAM_HSYNC_ACTIVE_LOW)
+		ret = ov6650_reg_rmw(client, REG_COMF, COMF_HREF_LOW, 0);
+	else
+		ret = ov6650_reg_rmw(client, REG_COMF, 0, COMF_HREF_LOW);
+	if (ret)
+		goto out;
+
+	if (flags & SOCAM_VSYNC_ACTIVE_HIGH)
+		ret = ov6650_reg_rmw(client, REG_COMJ, COMJ_VSYNC_HIGH, 0);
+	else
+		ret = ov6650_reg_rmw(client, REG_COMJ, 0, COMJ_VSYNC_HIGH);
+out:
+	return ret;
+}
+
+/* Request bus settings on camera side */
+static unsigned long ov6650_query_bus_param(struct soc_camera_device *icd)
+{
+	struct soc_camera_link *icl = to_soc_camera_link(icd);
+
+	unsigned long flags = SOCAM_MASTER | \
+		SOCAM_PCLK_SAMPLE_RISING | SOCAM_PCLK_SAMPLE_FALLING | \
+		SOCAM_HSYNC_ACTIVE_HIGH | SOCAM_HSYNC_ACTIVE_LOW | \
+		SOCAM_VSYNC_ACTIVE_HIGH | SOCAM_VSYNC_ACTIVE_LOW | \
+		SOCAM_DATA_ACTIVE_HIGH | SOCAM_DATAWIDTH_8;
+
+	return soc_camera_apply_sensor_flags(icl, flags);
+}
+
+/* Get status of additional camera capabilities */
+static int ov6650_g_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl)
+{
+	struct i2c_client *client = sd->priv;
+	struct ov6650 *priv = to_ov6650(client);
+	uint8_t reg;
+	int ret = 0;
+
+	switch (ctrl->id) {
+	case V4L2_CID_AUTOGAIN:
+		ctrl->value = priv->agc;
+		break;
+	case V4L2_CID_GAIN:
+		if (priv->agc) {
+			ret = ov6650_reg_read(client, REG_GAIN, &reg);
+			ctrl->value = reg;
+		} else {
+			ctrl->value = priv->gain;
+		}
+		break;
+	case V4L2_CID_AUTO_WHITE_BALANCE:
+		ctrl->value = priv->awb;
+		break;
+	case V4L2_CID_BLUE_BALANCE:
+		if (priv->awb) {
+			ret = ov6650_reg_read(client, REG_BLUE, &reg);
+			ctrl->value = reg;
+		} else {
+			ctrl->value = priv->blue;
+		}
+		break;
+	case V4L2_CID_RED_BALANCE:
+		if (priv->awb) {
+			ret = ov6650_reg_read(client, REG_RED, &reg);
+			ctrl->value = reg;
+		} else {
+			ctrl->value = priv->red;
+		}
+		break;
+	case V4L2_CID_SATURATION:
+		ctrl->value = priv->saturation;
+		break;
+	case V4L2_CID_HUE_AUTO:
+		ctrl->value = priv->hue_auto;
+		break;
+	case V4L2_CID_HUE:
+		if (priv->hue_auto) {
+			ret = ov6650_reg_read(client, REG_HUE, &reg);
+			ctrl->value = reg & 0x1f;
+		} else {
+			ctrl->value = priv->hue;
+		}
+		break;
+	case V4L2_CID_BRIGHTNESS:
+		ctrl->value = priv->brightness;
+		break;
+	case V4L2_CID_EXPOSURE_AUTO:
+		ctrl->value = priv->aec;
+		break;
+	case V4L2_CID_EXPOSURE:
+		if (priv->aec) {
+			ret = ov6650_reg_read(client, REG_AECH, &reg);
+			ctrl->value = reg;
+		} else {
+			ctrl->value = priv->exposure;
+		}
+		break;
+	case V4L2_CID_GAMMA:
+		ctrl->value = priv->gamma;
+		break;
+	case V4L2_CID_VFLIP:
+		ctrl->value = priv->vflip;
+		break;
+	case V4L2_CID_HFLIP:
+		ctrl->value = priv->hflip;
+		break;
+	}
+	return ret;
+}
+
+/* Set status of additional camera capabilities */
+static int ov6650_s_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl)
+{
+	struct i2c_client *client = sd->priv;
+	struct ov6650 *priv = to_ov6650(client);
+	bool automatic;
+	int ret = 0;
+
+	switch (ctrl->id) {
+	case V4L2_CID_AUTOGAIN:
+		if (ctrl->value) {
+			ret = ov6650_reg_write(client, REG_GAIN, DEF_GAIN);
+			if (ret)
+				break;
+			priv->gain = DEF_GAIN;
+			ret = ov6650_reg_rmw(client, REG_COMB, COMB_AGC, 0);
+		} else {
+			ret = ov6650_reg_rmw(client, REG_COMB, 0, COMB_AGC);
+		}
+		if (ret)
+			break;
+		priv->agc = ctrl->value;
+		break;
+	case V4L2_CID_GAIN:
+		ret = ov6650_reg_write(client, REG_GAIN, ctrl->value);
+		if (ret)
+			break;
+		priv->gain = ctrl->value;
+		automatic = (priv->gain == DEF_GAIN);
+		if (automatic)
+			ret = ov6650_reg_rmw(client, REG_COMB, COMB_AGC, 0);
+		else
+			ret = ov6650_reg_rmw(client, REG_COMB, 0, COMB_AGC);
+		if (ret)
+			break;
+		priv->agc = automatic;
+		break;
+	case V4L2_CID_AUTO_WHITE_BALANCE:
+		if (ctrl->value) {
+			ret = ov6650_reg_write(client, REG_BLUE, DEF_BLUE);
+			if (ret)
+				break;
+			priv->blue = DEF_BLUE;
+			ret = ov6650_reg_write(client, REG_RED, DEF_RED);
+			if (ret)
+				break;
+			priv->red = DEF_RED;
+			ret = ov6650_reg_rmw(client, REG_COMB, COMB_AWB, 0);
+		} else {
+			ret = ov6650_reg_rmw(client, REG_COMB, 0, COMB_AWB);
+		}
+		if (ret)
+			break;
+		priv->awb = ctrl->value;
+		break;
+	case V4L2_CID_BLUE_BALANCE:
+		ret = ov6650_reg_write(client, REG_BLUE, ctrl->value);
+		if (ret)
+			break;
+		priv->blue = ctrl->value;
+		automatic = (priv->blue == DEF_BLUE &&
+				priv->red == DEF_RED);
+		if (automatic)
+			ret = ov6650_reg_rmw(client, REG_COMB, COMB_AWB, 0);
+		else
+			ret = ov6650_reg_rmw(client, REG_COMB, 0, COMB_AWB);
+		if (ret)
+			break;
+		priv->awb = automatic;
+		break;
+	case V4L2_CID_RED_BALANCE:
+		ret = ov6650_reg_write(client, REG_RED, ctrl->value);
+		if (ret)
+			break;
+		priv->red = ctrl->value;
+		automatic = (priv->blue == DEF_BLUE &&
+				priv->red == DEF_RED);
+		if (automatic)
+			ret = ov6650_reg_rmw(client, REG_COMB, COMB_AWB, 0);
+		else
+			ret = ov6650_reg_rmw(client, REG_COMB, 0, COMB_AWB);
+		if (ret)
+			break;
+		priv->awb = automatic;
+		break;
+	case V4L2_CID_SATURATION:
+		ret = ov6650_reg_rmw(client, REG_SAT, SET_SAT(ctrl->value),
+				SET_SAT(SAT_MASK));
+		if (ret)
+			break;
+		priv->saturation = ctrl->value;
+		break;
+	case V4L2_CID_HUE_AUTO:
+		if (ctrl->value) {
+			ret = ov6650_reg_rmw(client, REG_HUE,
+					SET_HUE(DEF_HUE), SET_HUE(HUE_MASK));
+			if (ret)
+				break;
+			priv->hue = DEF_HUE;
+		} else {
+			ret = ov6650_reg_rmw(client, REG_HUE, HUE_EN, 0);
+		}
+		if (ret)
+			break;
+		priv->hue_auto = ctrl->value;
+		break;
+	case V4L2_CID_HUE:
+		ret = ov6650_reg_rmw(client, REG_HUE, SET_HUE(ctrl->value),
+				SET_HUE(HUE_MASK));
+		if (ret)
+			break;
+		priv->hue = ctrl->value;
+		priv->hue_auto = (priv->hue == DEF_HUE);
+		break;
+	case V4L2_CID_BRIGHTNESS:
+		ret = ov6650_reg_write(client, REG_BRT, ctrl->value);
+		if (ret)
+			break;
+		priv->brightness = ctrl->value;
+		break;
+	case V4L2_CID_EXPOSURE_AUTO:
+		switch (ctrl->value) {
+		case V4L2_EXPOSURE_AUTO:
+			ret = ov6650_reg_write(client, REG_AECH, DEF_AECH);
+			if (ret)
+				break;
+			priv->exposure = DEF_AECH;
+			ret = ov6650_reg_rmw(client, REG_COMB, COMB_AEC, 0);
+			break;
+		default:
+			ret = ov6650_reg_rmw(client, REG_COMB, 0, COMB_AEC);
+			break;
+		}
+		if (ret)
+			break;
+		priv->aec = ctrl->value;
+		break;
+	case V4L2_CID_EXPOSURE:
+		ret = ov6650_reg_write(client, REG_AECH, ctrl->value);
+		if (ret)
+			break;
+		priv->exposure = ctrl->value;
+		automatic = (priv->exposure == DEF_AECH);
+		if (automatic)
+			ret = ov6650_reg_rmw(client, REG_COMB, COMB_AEC, 0);
+		else
+			ret = ov6650_reg_rmw(client, REG_COMB, 0, COMB_AEC);
+		if (ret)
+			break;
+		priv->aec = automatic ? V4L2_EXPOSURE_AUTO :
+				V4L2_EXPOSURE_MANUAL;
+		break;
+	case V4L2_CID_GAMMA:
+		ret = ov6650_reg_write(client, REG_GAM1, ctrl->value);
+		if (ret)
+			break;
+		priv->gamma = ctrl->value;
+		break;
+	case V4L2_CID_VFLIP:
+		if (ctrl->value)
+			ret = ov6650_reg_rmw(client, REG_COMB,
+							COMB_FLIP_V, 0);
+		else
+			ret = ov6650_reg_rmw(client, REG_COMB,
+							0, COMB_FLIP_V);
+		if (ret)
+			break;
+		priv->vflip = ctrl->value;
+		break;
+	case V4L2_CID_HFLIP:
+		if (ctrl->value)
+			ret = ov6650_reg_rmw(client, REG_COMB,
+							COMB_FLIP_H, 0);
+		else
+			ret = ov6650_reg_rmw(client, REG_COMB,
+							0, COMB_FLIP_H);
+		if (ret)
+			break;
+		priv->hflip = ctrl->value;
+		break;
+	}
+
+	return ret;
+}
+
+/* Get chip identification */
+static int ov6650_g_chip_ident(struct v4l2_subdev *sd,
+				struct v4l2_dbg_chip_ident *id)
+{
+	id->ident	= V4L2_IDENT_OV6650;
+	id->revision	= 0;
+
+	return 0;
+}
+
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+static int ov6650_get_register(struct v4l2_subdev *sd,
+				struct v4l2_dbg_register *reg)
+{
+	struct i2c_client *client = sd->priv;
+	int ret;
+	u8 val;
+
+	if (reg->reg & ~0xff)
+		return -EINVAL;
+
+	reg->size = 1;
+
+	ret = ov6650_reg_read(client, reg->reg, &val);
+	if (ret)
+		return ret;
+
+	reg->val = (__u64)val;
+
+	return 0;
+}
+
+static int ov6650_set_register(struct v4l2_subdev *sd,
+				struct v4l2_dbg_register *reg)
+{
+	struct i2c_client *client = sd->priv;
+
+	if (reg->reg & ~0xff || reg->val & ~0xff)
+		return -EINVAL;
+
+	return ov6650_reg_write(client, reg->reg, reg->val);
+}
+#endif
+
+/* select nearest higher resolution for capture */
+static void ov6650_res_roundup(u32 *width, u32 *height)
+{
+	int i;
+	enum { QCIF, CIF };
+	int res_x[] = { 176, 352 };
+	int res_y[] = { 144, 288 };
+
+	for (i = 0; i < ARRAY_SIZE(res_x); i++) {
+		if (res_x[i] >= *width && res_y[i] >= *height) {
+			*width = res_x[i];
+			*height = res_y[i];
+			return;
+		}
+	}
+
+	*width = res_x[CIF];
+	*height = res_y[CIF];
+}
+
+/* program default register values */
+static int ov6650_prog_dflt(struct i2c_client *client)
+{
+	int i, ret;
+
+	dev_dbg(&client->dev, "reinitializing\n");
+
+	for (i = 0; i < ARRAY_SIZE(ov6650_regs_dflt); i++) {
+		ret = ov6650_reg_write(client, ov6650_regs_dflt[i].reg,
+						ov6650_regs_dflt[i].val);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+/* set the format we will capture in */
+static int ov6650_s_fmt(struct v4l2_subdev *sd,
+			struct v4l2_mbus_framefmt *mf)
+{
+	struct i2c_client *client = sd->priv;
+	struct soc_camera_device *icd	= client->dev.platform_data;
+	struct soc_camera_sense *sense = icd->sense;
+	struct ov6650 *priv = to_ov6650(client);
+	enum v4l2_colorspace cspace;
+	enum v4l2_mbus_pixelcode code = mf->code;
+	unsigned long pclk;
+	u8 coma_set = 0, coma_mask = 0, coml_set = 0, coml_mask = 0, clkrc;
+	int ret;
+
+	/* select color matrix configuration for given color encoding */
+	switch (code) {
+	case V4L2_MBUS_FMT_GREY8_1X8:
+		dev_dbg(&client->dev, "pixel format GREY8_1X8\n");
+		coma_set |= COMA_BW;
+		coma_mask |= COMA_RGB | COMA_WORD_SWAP | COMA_BYTE_SWAP;
+		coml_mask |= COML_ONE_CHANNEL;
+		cspace = V4L2_COLORSPACE_JPEG;
+		priv->pclk_max = 4000000;
+		break;
+	case V4L2_MBUS_FMT_YUYV8_2X8_LE:
+		dev_dbg(&client->dev, "pixel format YUYV8_2X8_LE\n");
+		coma_set |= COMA_WORD_SWAP;
+		coma_mask |= COMA_RGB | COMA_BW | COMA_BYTE_SWAP;
+		goto yuv;
+	case V4L2_MBUS_FMT_YVYU8_2X8_LE:
+		dev_dbg(&client->dev, "pixel format YVYU8_2X8_LE (untested)\n");
+		coma_mask |= COMA_RGB | COMA_BW | COMA_WORD_SWAP |
+				COMA_BYTE_SWAP;
+		goto yuv;
+	case V4L2_MBUS_FMT_YUYV8_2X8_BE:
+		dev_dbg(&client->dev, "pixel format YUYV8_2X8_BE\n");
+		if (mf->width == W_CIF) {
+			coma_set |= COMA_BYTE_SWAP | COMA_WORD_SWAP;
+			coma_mask |= COMA_RGB | COMA_BW;
+		} else {
+			coma_set |= COMA_BYTE_SWAP;
+			coma_mask |= COMA_RGB | COMA_BW | COMA_WORD_SWAP;
+		}
+		goto yuv;
+	case V4L2_MBUS_FMT_YVYU8_2X8_BE:
+		dev_dbg(&client->dev, "pixel format YVYU8_2X8_BE (untested)\n");
+		if (mf->width == W_CIF) {
+			coma_set |= COMA_BYTE_SWAP;
+			coma_mask |= COMA_RGB | COMA_BW | COMA_WORD_SWAP;
+		} else {
+			coma_set |= COMA_BYTE_SWAP | COMA_WORD_SWAP;
+			coma_mask |= COMA_RGB | COMA_BW;
+		}
+yuv:
+		coml_set |= COML_ONE_CHANNEL;
+		cspace = V4L2_COLORSPACE_JPEG;
+		priv->pclk_max = 8000000;
+		break;
+	case V4L2_MBUS_FMT_SBGGR8_1X8:
+		dev_dbg(&client->dev, "pixel format SBGGR8_1X8 (untested)\n");
+		coma_set |= COMA_RAW_RGB | COMA_RGB;
+		coma_mask |= COMA_BW | COMA_BYTE_SWAP | COMA_WORD_SWAP;
+		coml_mask |= COML_ONE_CHANNEL;
+		cspace = V4L2_COLORSPACE_SRGB;
+		priv->pclk_max = 4000000;
+		break;
+	default:
+		dev_err(&client->dev, "Pixel format not handled : %x\n", code);
+		return -EINVAL;
+	}
+
+	/* select register configuration for given resolution */
+	ov6650_res_roundup(&mf->width, &mf->height);
+
+	switch (mf->width) {
+	case W_QCIF:
+		dev_dbg(&client->dev, "resolution QCIF\n");
+		priv->qcif = 1;
+		coma_set |= COMA_QCIF;
+		priv->pclk_max /= 2;
+		break;
+	case W_CIF:
+		dev_dbg(&client->dev, "resolution CIF\n");
+		priv->qcif = 0;
+		coma_mask |= COMA_QCIF;
+		break;
+	default:
+		dev_err(&client->dev, "unspported resolution!\n");
+		return -EINVAL;
+	}
+
+	if (priv->timeperframe.numerator && priv->timeperframe.denominator)
+		pclk = priv->pclk_max * priv->timeperframe.denominator /
+				(FRAME_RATE_MAX * priv->timeperframe.numerator);
+	else
+		pclk = priv->pclk_max;
+
+	if (sense) {
+		if (sense->master_clock == 8000000) {
+			dev_dbg(&client->dev, "8MHz input clock\n");
+			clkrc = CLKRC_6MHz;
+		} else if (sense->master_clock == 12000000) {
+			dev_dbg(&client->dev, "12MHz input clock\n");
+			clkrc = CLKRC_12MHz;
+		} else if (sense->master_clock == 16000000) {
+			dev_dbg(&client->dev, "16MHz input clock\n");
+			clkrc = CLKRC_16MHz;
+		} else if (sense->master_clock == 24000000) {
+			dev_dbg(&client->dev, "24MHz input clock\n");
+			clkrc = CLKRC_24MHz;
+		} else {
+			dev_err(&client->dev,
+				"unspported input clock, check platform data"
+				"\n");
+			return -EINVAL;
+		}
+		priv->pclk_limit = sense->pixel_clock_max;
+		if (priv->pclk_limit &&
+				(priv->pclk_limit < pclk))
+			pclk = priv->pclk_limit;
+	} else {
+		priv->pclk_limit = 0;
+		clkrc = 0xc0;
+		dev_dbg(&client->dev, "using default 24MHz input clock\n");
+	}
+
+	clkrc |= (priv->pclk_max - 1) / pclk;
+	pclk = priv->pclk_max / GET_CLKRC_DIV(clkrc);
+	dev_dbg(&client->dev, "pixel clock divider: %ld.%ld\n",
+			sense->master_clock / pclk,
+			10 * sense->master_clock % pclk / pclk);
+
+	ov6650_reset(client);
+
+	ret = ov6650_prog_dflt(client);
+	if (ret)
+		return ret;
+
+
+	ret = ov6650_reg_rmw(client, REG_COMA, coma_set, coma_mask);
+	if (!ret)
+		ret = ov6650_reg_write(client, REG_CLKRC, clkrc);
+	if (!ret)
+		ret = ov6650_reg_rmw(client, REG_COML, coml_set, coml_mask);
+
+	if (!ret) {
+		mf->code	= code;
+		mf->colorspace	= cspace;
+	}
+
+	return ret;
+}
+
+static int ov6650_try_fmt(struct v4l2_subdev *sd,
+			  struct v4l2_mbus_framefmt *mf)
+{
+	ov6650_res_roundup(&mf->width, &mf->height);
+
+	mf->field = V4L2_FIELD_NONE;
+
+	switch (mf->code) {
+	case V4L2_MBUS_FMT_Y10_1X10:
+		mf->code = V4L2_MBUS_FMT_GREY8_1X8;
+	case V4L2_MBUS_FMT_GREY8_1X8:
+	case V4L2_MBUS_FMT_YVYU8_2X8_LE:
+	case V4L2_MBUS_FMT_YUYV8_2X8_LE:
+	case V4L2_MBUS_FMT_YVYU8_2X8_BE:
+	case V4L2_MBUS_FMT_YUYV8_2X8_BE:
+		mf->colorspace = V4L2_COLORSPACE_JPEG;
+		break;
+	default:
+		mf->code = V4L2_MBUS_FMT_SBGGR8_1X8;
+	case V4L2_MBUS_FMT_SBGGR8_1X8:
+		mf->colorspace = V4L2_COLORSPACE_SRGB;
+		break;
+	}
+
+	return 0;
+}
+
+static int ov6650_enum_fmt(struct v4l2_subdev *sd, unsigned int index,
+			   enum v4l2_mbus_pixelcode *code)
+{
+	if ((unsigned int)index >= ARRAY_SIZE(ov6650_codes))
+		return -EINVAL;
+
+	*code = ov6650_codes[index];
+	return 0;
+}
+
+static int ov6650_cropcap(struct v4l2_subdev *sd, struct v4l2_cropcap *a)
+{
+	struct i2c_client *client = sd->priv;
+	struct ov6650 *priv = to_ov6650(client);
+	int shift = !priv->qcif;
+
+	if (a->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+		return -EINVAL;
+
+	/* Crop limits depend on selected frame format (CIF/QCIF) */
+	a->bounds.left			= DEF_HSTRT << shift;
+	a->bounds.top			= DEF_VSTRT << shift;
+	a->bounds.width			= W_QCIF << shift;
+	a->bounds.height		= H_QCIF << shift;
+	/* REVISIT: should defrect provide actual or default geometry? */
+	a->defrect			= a->bounds;
+	a->pixelaspect.numerator	= 1;
+	a->pixelaspect.denominator	= 1;
+
+	return 0;
+}
+
+static int ov6650_g_crop(struct v4l2_subdev *sd, struct v4l2_crop *a)
+{
+	struct i2c_client *client = sd->priv;
+	struct ov6650 *priv = to_ov6650(client);
+	struct v4l2_rect *rect = &a->c;
+	int shift = !priv->qcif;
+	u8 hstrt, vstrt, hstop, vstop;
+	int ret;
+
+	if (a->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+		return -EINVAL;
+
+	ret = ov6650_reg_read(client, REG_HSTRT, &hstrt);
+	if (!ret)
+		ret = ov6650_reg_read(client, REG_HSTOP, &hstop);
+	if (!ret)
+		ret = ov6650_reg_read(client, REG_VSTRT, &vstrt);
+	if (!ret)
+		ret = ov6650_reg_read(client, REG_VSTOP, &vstop);
+
+	if (!ret) {
+		rect->left	= hstrt << shift;
+		rect->top	= vstrt << shift;
+		rect->width	= (hstop - hstrt) << shift;
+		rect->height	= (vstop - vstrt) << shift;
+	}
+
+	return ret;
+}
+
+static int ov6650_s_crop(struct v4l2_subdev *sd, struct v4l2_crop *a)
+{
+	struct i2c_client *client = sd->priv;
+	struct ov6650 *priv = to_ov6650(client);
+	struct v4l2_rect *rect = &a->c;
+	int shift = !priv->qcif;
+	u8 hstrt, vstrt, hstop, vstop;
+	int ret;
+
+	if (a->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+		return -EINVAL;
+
+	hstrt = rect->left >> shift;
+	vstrt = rect->top >> shift;
+	hstop = hstrt + (rect->width >> shift);
+	vstop = vstrt + (rect->height >> shift);
+
+	if ((hstop > DEF_HSTOP) || (vstop > DEF_VSTOP)) {
+		dev_err(&client->dev, "Invalid window geometry!\n");
+		return -EINVAL;
+	}
+
+	ret = ov6650_reg_write(client, REG_HSTRT, hstrt);
+	if (!ret)
+		ret = ov6650_reg_write(client, REG_HSTOP, hstop);
+	if (!ret)
+		ret = ov6650_reg_write(client, REG_VSTRT, vstrt);
+	if (!ret)
+		ret = ov6650_reg_write(client, REG_VSTOP, vstop);
+
+	return ret;
+}
+
+static int ov6650_g_parm(struct v4l2_subdev *sd, struct v4l2_streamparm *parms)
+{
+	struct i2c_client *client = sd->priv;
+	struct v4l2_captureparm *cp = &parms->parm.capture;
+	u8 clkrc;
+	int ret;
+
+	if (parms->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+		return -EINVAL;
+
+	ret = ov6650_reg_read(client, REG_CLKRC, &clkrc);
+	if (ret < 0)
+		return ret;
+
+	memset(cp, 0, sizeof(struct v4l2_captureparm));
+	cp->capability = V4L2_CAP_TIMEPERFRAME;
+	cp->timeperframe.numerator = GET_CLKRC_DIV(clkrc);
+	cp->timeperframe.denominator = FRAME_RATE_MAX;
+
+	dev_dbg(&client->dev, "Frame interval: %u/%u\n",
+		cp->timeperframe.numerator, cp->timeperframe.denominator);
+
+	return 0;
+}
+
+static int ov6650_s_parm(struct v4l2_subdev *sd, struct v4l2_streamparm *parms)
+{
+	struct i2c_client *client = sd->priv;
+	struct ov6650 *priv = to_ov6650(client);
+	struct v4l2_captureparm *cp = &parms->parm.capture;
+	struct v4l2_fract *tpf = &cp->timeperframe;
+	int div, ret;
+
+	if (parms->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+		return -EINVAL;
+
+	if (cp->extendedmode != 0)
+		return -EINVAL;
+
+	if (tpf->numerator == 0 || tpf->denominator == 0)
+		div = 1;  /* Reset to full rate */
+	else
+		div = (tpf->numerator * FRAME_RATE_MAX) / tpf->denominator;
+
+	if (div == 0)
+		div = 1;
+	else if (div > CLKRC_DIV_MASK + 1)
+		div = CLKRC_DIV_MASK + 1;
+
+	if (priv->pclk_max && priv->pclk_limit) {
+		ret = (priv->pclk_max - 1) / priv->pclk_limit;
+		if (div < ret)
+			div = ret;
+	}
+
+	ret = ov6650_reg_rmw(client, REG_CLKRC, div - 1, CLKRC_DIV_MASK);
+	if (!ret) {
+		priv->timeperframe.numerator = tpf->numerator = FRAME_RATE_MAX;
+		priv->timeperframe.denominator = tpf->denominator = div;
+	}
+
+	return ret;
+}
+
+static int ov6650_video_probe(struct soc_camera_device *icd,
+				struct i2c_client *client)
+{
+	u8		pidh, pidl, midh, midl;
+	int		ret = 0;
+
+	/*
+	 * check and show product ID and manufacturer ID
+	 */
+	ret = ov6650_reg_read(client, REG_PIDH, &pidh);
+	if (!ret)
+		ret = ov6650_reg_read(client, REG_PIDL, &pidl);
+	if (!ret)
+		ret = ov6650_reg_read(client, REG_MIDH, &midh);
+	if (!ret)
+		ret = ov6650_reg_read(client, REG_MIDL, &midl);
+
+	if (ret)
+		goto err;
+
+	if ((pidh != OV6650_PIDH) || (pidl != OV6650_PIDL)) {
+		dev_err(&client->dev, "Product ID error %x:%x\n", pidh, pidl);
+		ret = -ENODEV;
+		goto err;
+	}
+
+	dev_info(&client->dev, "ov6650 Product ID %0x:%0x Manufacturer ID %x:%x"
+			"\n", pidh, pidl, midh, midl);
+
+err:
+	return ret;
+}
+
+static struct soc_camera_ops ov6650_ops = {
+	.set_bus_param		= ov6650_set_bus_param,
+	.query_bus_param	= ov6650_query_bus_param,
+	.controls		= ov6650_controls,
+	.num_controls		= ARRAY_SIZE(ov6650_controls),
+};
+
+static struct v4l2_subdev_core_ops ov6650_core_ops = {
+	.g_ctrl			= ov6650_g_ctrl,
+	.s_ctrl			= ov6650_s_ctrl,
+	.g_chip_ident		= ov6650_g_chip_ident,
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+	.g_register		= ov6650_get_register,
+	.s_register		= ov6650_set_register,
+#endif
+
+};
+
+static struct v4l2_subdev_video_ops ov6650_video_ops = {
+	.s_stream	= ov6650_s_stream,
+	.s_mbus_fmt	= ov6650_s_fmt,
+	.try_mbus_fmt	= ov6650_try_fmt,
+	.enum_mbus_fmt	= ov6650_enum_fmt,
+	.cropcap	= ov6650_cropcap,
+	.g_crop		= ov6650_g_crop,
+	.s_crop		= ov6650_s_crop,
+	.g_parm		= ov6650_g_parm,
+	.s_parm		= ov6650_s_parm,
+
+};
+
+static struct v4l2_subdev_ops ov6650_subdev_ops = {
+	.core	= &ov6650_core_ops,
+	.video	= &ov6650_video_ops,
+};
+
+/*
+ * i2c_driver function
+ */
+static int ov6650_probe(struct i2c_client *client,
+			const struct i2c_device_id *did)
+{
+	struct ov6650 *priv;
+	struct soc_camera_device *icd	= client->dev.platform_data;
+	struct soc_camera_link *icl;
+	int ret;
+
+	if (!icd) {
+		dev_err(&client->dev, "Missing soc-camera data!\n");
+		return -EINVAL;
+	}
+
+	icl = to_soc_camera_link(icd);
+	if (!icl) {
+		dev_err(&client->dev, "Missing platform_data for driver\n");
+		return -EINVAL;
+	}
+
+	priv = kzalloc(sizeof(struct ov6650), GFP_KERNEL);
+	if (!priv) {
+		dev_err(&client->dev,
+			"Failed to allocate memory for private data!\n");
+		return -ENOMEM;
+	}
+
+	v4l2_i2c_subdev_init(&priv->subdev, client, &ov6650_subdev_ops);
+
+	icd->ops	= &ov6650_ops;
+
+	ret = ov6650_video_probe(icd, client);
+
+	if (ret) {
+		icd->ops = NULL;
+		i2c_set_clientdata(client, NULL);
+		kfree(priv);
+	}
+
+	return ret;
+}
+
+static int ov6650_remove(struct i2c_client *client)
+{
+	struct ov6650 *priv = to_ov6650(client);
+
+	i2c_set_clientdata(client, NULL);
+	kfree(priv);
+	return 0;
+}
+
+static const struct i2c_device_id ov6650_id[] = {
+	{ "ov6650", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ov6650_id);
+
+static struct i2c_driver ov6650_i2c_driver = {
+	.driver = {
+		.name = "ov6650",
+	},
+	.probe    = ov6650_probe,
+	.remove   = ov6650_remove,
+	.id_table = ov6650_id,
+};
+
+static int __init ov6650_module_init(void)
+{
+	return i2c_add_driver(&ov6650_i2c_driver);
+}
+
+static void __exit ov6650_module_exit(void)
+{
+	i2c_del_driver(&ov6650_i2c_driver);
+}
+
+module_init(ov6650_module_init);
+module_exit(ov6650_module_exit);
+
+MODULE_DESCRIPTION("SoC Camera driver for OmniVision OV6650");
+MODULE_AUTHOR("Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>");
+MODULE_LICENSE("GPL v2");
--- linux-2.6.35-rc3.orig/include/media/v4l2-chip-ident.h	2010-06-26 15:56:15.000000000 +0200
+++ linux-2.6.35-rc3/include/media/v4l2-chip-ident.h	2010-06-26 17:28:09.000000000 +0200
@@ -70,6 +70,7 @@ enum {
 	V4L2_IDENT_OV9655 = 255,
 	V4L2_IDENT_SOI968 = 256,
 	V4L2_IDENT_OV9640 = 257,
+	V4L2_IDENT_OV6650 = 258,
 
 	/* module saa7146: reserved range 300-309 */
 	V4L2_IDENT_SAA7146 = 300,

Re: [RFC] [PATCH 3/6] SoC Camera: add driver for OV6650 sensor

[Guennadi Liakhovetski]

On Sun, 18 Jul 2010, Janusz Krzysztofik wrote:

> This patch provides a V4L2 SoC Camera driver for OV6650 camera sensor, found 
> on OMAP1 SoC based Amstrad Delta videophone.

Have you also had a look at drivers/media/video/gspca/sonixb.c - in also 
supports ov6650 among other sensors.

> Since I have no experience with camera sensors, and the sensor documentation I 
> was able to find was not very comprehensive, I left most settings at their 
> default (reset) values, except for:
> - those required for proper mediabus parameters and picture format setup,
> - those used by controls.
> Resulting picture quality is far from perfect, but better than nothing.
> 
> In order to be able to get / set the sensor frame rate from userspace, I 
> decided to provide two not yet SoC camera supported operations, g_parm and 
> s_parm. These can be used after applying patch 4/6 from this series, 
> "SoC Camera: add support for g_parm / s_parm operations".
> 
> Created and tested against linux-2.6.35-rc3 on Amstrad Delta.
> 
> Signed-off-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
> ---
>  drivers/media/video/Kconfig     |    6
>  drivers/media/video/Makefile    |    1
>  drivers/media/video/ov6650.c    | 1336 ++++++++++++++++++++++++++++++++++++++++
>  include/media/v4l2-chip-ident.h |    1
>  4 files changed, 1344 insertions(+)
> 
> --- linux-2.6.35-rc3.orig/drivers/media/video/Kconfig	2010-06-26 15:55:29.000000000 +0200
> +++ linux-2.6.35-rc3/drivers/media/video/Kconfig	2010-07-02 04:12:02.000000000 +0200
> @@ -913,6 +913,12 @@ config SOC_CAMERA_PLATFORM
>  	help
>  	  This is a generic SoC camera platform driver, useful for testing
>  
> +config SOC_CAMERA_OV6650
> +	tristate "ov6650 sensor support"
> +	depends on SOC_CAMERA && I2C
> +	help
> +	  This is a V4L2 SoC camera driver for the OmniVision OV6650 sensor
> +
>  config SOC_CAMERA_OV772X
>  	tristate "ov772x camera support"
>  	depends on SOC_CAMERA && I2C
> --- linux-2.6.35-rc3.orig/drivers/media/video/Makefile	2010-06-26 15:55:29.000000000 +0200
> +++ linux-2.6.35-rc3/drivers/media/video/Makefile	2010-06-26 17:28:09.000000000 +0200
> @@ -79,6 +79,7 @@ obj-$(CONFIG_SOC_CAMERA_MT9M111)	+= mt9m
>  obj-$(CONFIG_SOC_CAMERA_MT9T031)	+= mt9t031.o
>  obj-$(CONFIG_SOC_CAMERA_MT9T112)	+= mt9t112.o
>  obj-$(CONFIG_SOC_CAMERA_MT9V022)	+= mt9v022.o
> +obj-$(CONFIG_SOC_CAMERA_OV6650)		+= ov6650.o
>  obj-$(CONFIG_SOC_CAMERA_OV772X)		+= ov772x.o
>  obj-$(CONFIG_SOC_CAMERA_OV9640)		+= ov9640.o
>  obj-$(CONFIG_SOC_CAMERA_RJ54N1)		+= rj54n1cb0c.o
> --- linux-2.6.35-rc3.orig/drivers/media/video/ov6650.c	1970-01-01 01:00:00.000000000 +0100
> +++ linux-2.6.35-rc3/drivers/media/video/ov6650.c	2010-07-18 02:06:22.000000000 +0200
> @@ -0,0 +1,1336 @@
> +/*
> + * V4L2 SoC Camera driver for OmniVision OV6650 Camera Sensor
> + *
> + * Copyright (C) 2010 Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
> + *
> + * Based on OmniVision OV96xx Camera Driver
> + * Copyright (C) 2009 Marek Vasut <marek.vasut@gmail.com>
> + *
> + * Based on ov772x camera driver:
> + * Copyright (C) 2008 Renesas Solutions Corp.
> + * Kuninori Morimoto <morimoto.kuninori@renesas.com>
> + *
> + * Based on ov7670 and soc_camera_platform driver,
> + * Copyright 2006-7 Jonathan Corbet <corbet@lwn.net>
> + * Copyright (C) 2008 Magnus Damm
> + * Copyright (C) 2008, Guennadi Liakhovetski <kernel@pengutronix.de>
> + *
> + * Hardware specific bits initialy based on former work by Matt Callow
> + * drivers/media/video/omap/sensor_ov6650.c
> + * Copyright (C) 2006 Matt Callow
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/i2c.h>
> +#include <linux/slab.h>
> +#include <linux/delay.h>
> +#include <media/v4l2-chip-ident.h>
> +#include <media/soc_camera.h>

Please, sort headers alphabetically (media/ and linux/ separately, of 
course).

> +
> +
> +/* Register definitions */
> +#define	REG_GAIN		0x00	/* range 00 - 3F */
> +#define	REG_BLUE		0x01
> +#define	REG_RED			0x02
> +#define	REG_SAT			0x03	/* [7:4] saturation [0:3] reserved */
> +#define	REG_HUE			0x04	/* [7:6] rsrvd [5] hue en [4:0] hue */
> +
> +#define	REG_BRT			0x06
> +
> +#define	REG_PIDH		0x0a
> +#define	REG_PIDL		0x0b
> +
> +#define	REG_AECH		0x10
> +#define	REG_CLKRC		0x11	/* Data Format and Internal Clock */
> +					/* [7:6] Input system clock (MHz)*/
> +					/*   00=8, 01=12, 10=16, 11=24 */
> +					/* [5:0]: Internal Clock Pre-Scaler */
> +#define	REG_COMA		0x12	/* [7] Reset */
> +#define	REG_COMB		0x13
> +#define	REG_COMC		0x14
> +#define	REG_COMD		0x15
> +#define REG_COML		0x16

You used TAB in most defines and a space in this one and a few ones below. 
Please, use the same for all (I personally would just use a space).

> +#define	REG_HSTRT		0x17
> +#define	REG_HSTOP		0x18
> +#define	REG_VSTRT		0x19
> +#define	REG_VSTOP		0x1a
> +#define	REG_PSHFT		0x1b
> +#define	REG_MIDH		0x1c
> +#define	REG_MIDL		0x1d
> +#define	REG_HSYNS		0x1e
> +#define	REG_HSYNE		0x1f
> +#define	REG_COME		0x20
> +#define	REG_YOFF		0x21
> +#define	REG_UOFF		0x22
> +#define	REG_VOFF		0x23
> +#define	REG_AEW			0x24
> +#define	REG_AEB			0x25
> +#define	REG_COMF		0x26
> +#define	REG_COMG		0x27
> +#define	REG_COMH		0x28
> +#define REG_COMI		0x29
> +
> +#define	REG_FRARL		0x2b
> +#define	REG_COMJ		0x2c
> +#define	REG_COMK		0x2d
> +#define	REG_AVGY		0x2e
> +#define	REG_REF0		0x2f
> +#define	REG_REF1		0x30
> +#define	REG_REF2		0x31
> +#define	REG_FRAJH		0x32
> +#define	REG_FRAJL		0x33
> +#define	REG_FACT		0x34
> +#define REG_L1AEC		0x35
> +#define REG_AVGU		0x36
> +#define	REG_AVGV		0x37
> +
> +#define	REG_SPCB		0x60
> +#define	REG_SPCC		0x61
> +#define	REG_GAM1		0x62
> +#define	REG_GAM2		0x63
> +#define	REG_GAM3		0x64
> +#define	REG_SPCD		0x65
> +
> +#define	REG_SPCE		0x68
> +#define	REG_ADCL		0x69
> +
> +#define	REG_RMCO		0x6c
> +#define	REG_GMCO		0x6d
> +#define	REG_BMCO		0x6e
> +
> +#define NUM_REGS		(REG_BMCO + 1)

NUM_REGS is unused, don't need to define it.

> +
> +
> +/* Register bits, values, etc. */
> +#define OV6650_PIDH		0x66	/* high byte of product ID number */
> +#define OV6650_PIDL		0x50	/* low byte of product ID number */
> +#define OV6650_MIDH		0x7F	/* high byte of mfg ID */
> +#define OV6650_MIDL		0xA2	/* low byte of mfg ID */
> +
> +#define DEF_GAIN		0x00
> +#define DEF_BLUE		0x80
> +#define DEF_RED			0x80
> +
> +#define SAT_SHIFT		4
> +#define SAT_MASK		0xf
> +#define SET_SAT(x)		(((x) & SAT_MASK) << SAT_SHIFT)

Nitpicking, but I would

+#define SAT_SHIFT		4
+#define SAT_MASK		0xf0
+#define SET_SAT(x)		(((x) << SAT_SHIFT) & SAT_MASK)

Advantage: your SAT_MASK is already correctly shifted, so, you don't have 
to you SET_SAT(SAT_MASK) to get to the register value.

> +
> +#define HUE_EN			BIT(5)

You have to #include <linux/bitops.h> for the BIT() macro

> +#define HUE_MASK		0x1f
> +#define DEF_HUE			0x10
> +#define SET_HUE(x)		((x) == DEF_HUE ? (x) : \
> +						HUE_EN | ((x) & HUE_MASK))
> +
> +#define DEF_AECH		0x4D
> +
> +#define	CLKRC_6MHz		0x00
> +#define	CLKRC_12MHz		0x40
> +#define	CLKRC_16MHz		0x80
> +#define	CLKRC_24MHz		0xc0
> +#define	CLKRC_DIV_MASK		0x3f
> +#define	GET_CLKRC_DIV(x)	(((x) & CLKRC_DIV_MASK) + 1)
> +
> +#define COMA_RESET		BIT(7)
> +#define COMA_QCIF		BIT(5)
> +#define COMA_RAW_RGB		BIT(4)
> +#define COMA_RGB		BIT(3)
> +#define COMA_BW			BIT(2)
> +#define COMA_WORD_SWAP		BIT(1)
> +#define COMA_BYTE_SWAP		BIT(0)
> +#define DEF_COMA		0x00
> +
> +#define	COMB_FLIP_V		BIT(7)
> +#define	COMB_FLIP_H		BIT(5)
> +#define COMB_AWB		BIT(2)
> +#define COMB_AGC		BIT(1)
> +#define COMB_AEC		BIT(0)
> +
> +#define COML_ONE_CHANNEL	BIT(7)
> +
> +#define DEF_HSTRT		0x24
> +#define DEF_HSTOP		0xd4
> +#define DEF_VSTRT		0x04
> +#define DEF_VSTOP		0x94
> +
> +#define COMF_HREF_LOW		BIT(4)
> +
> +#define COMJ_PCLK_RISING	BIT(4)
> +#define COMJ_VSYNC_HIGH		BIT(0)
> +
> +/* supported resolutions */
> +#define W_QCIF			(DEF_HSTOP - DEF_HSTRT)
> +#define W_CIF			(W_QCIF << 1)
> +#define H_QCIF			(DEF_VSTOP - DEF_VSTRT)
> +#define H_CIF			(H_QCIF << 1)
> +
> +#define FRAME_RATE_MAX		30
> +
> +
> +struct ov6650_reg {
> +	u8	reg;
> +	u8	val;
> +};
> +
> +struct ov6650 {
> +	struct v4l2_subdev	subdev;
> +
> +	int			gain;
> +	int			blue;
> +	int			red;
> +	int			saturation;
> +	int			hue;
> +	int			brightness;
> +	int			exposure;
> +	int			gamma;
> +	bool			vflip;
> +	bool			hflip;
> +	bool			awb;
> +	bool			agc;
> +	int			aec;
> +	bool			hue_auto;
> +	bool			qcif;
> +	unsigned long		pclk_max;	/* from resolution and format */
> +	unsigned long		pclk_limit;	/* from host */
> +	struct v4l2_fract	timeperframe;	/* as requested with s_parm */
> +};
> +
> +
> +/* default register setup */
> +static const struct ov6650_reg ov6650_regs_dflt[] = {
> +	{ REG_COMA,	DEF_COMA },	/* ~COMA_RESET */
> +};
> +
> +static enum v4l2_mbus_pixelcode ov6650_codes[] = {
> +	V4L2_MBUS_FMT_YUYV8_2X8_LE,
> +	V4L2_MBUS_FMT_YUYV8_2X8_BE,
> +	V4L2_MBUS_FMT_YVYU8_2X8_LE,
> +	V4L2_MBUS_FMT_YVYU8_2X8_BE,
> +	V4L2_MBUS_FMT_SBGGR8_1X8,
> +	V4L2_MBUS_FMT_GREY8_1X8,
> +};
> +
> +static const struct v4l2_queryctrl ov6650_controls[] = {
> +	{
> +		.id		= V4L2_CID_AUTOGAIN,
> +		.type		= V4L2_CTRL_TYPE_BOOLEAN,
> +		.name		= "AGC",
> +		.minimum	= 0,
> +		.maximum	= 1,
> +		.step		= 1,
> +		.default_value	= 1,
> +	},
> +	{
> +		.id		= V4L2_CID_GAIN,
> +		.type		= V4L2_CTRL_TYPE_INTEGER,
> +		.name		= "Gain",
> +		.minimum	= 0,
> +		.maximum	= 0x3f,
> +		.step		= 1,
> +		.default_value	= DEF_GAIN,
> +	},
> +	{
> +		.id		= V4L2_CID_AUTO_WHITE_BALANCE,
> +		.type		= V4L2_CTRL_TYPE_BOOLEAN,
> +		.name		= "AWB",
> +		.minimum	= 0,
> +		.maximum	= 1,
> +		.step		= 1,
> +		.default_value	= 1,
> +	},
> +	{
> +		.id		= V4L2_CID_BLUE_BALANCE,
> +		.type		= V4L2_CTRL_TYPE_INTEGER,
> +		.name		= "Blue",
> +		.minimum	= 0,
> +		.maximum	= 0xff,
> +		.step		= 1,
> +		.default_value	= DEF_BLUE,
> +	},
> +	{
> +		.id		= V4L2_CID_RED_BALANCE,
> +		.type		= V4L2_CTRL_TYPE_INTEGER,
> +		.name		= "Red",
> +		.minimum	= 0,
> +		.maximum	= 0xff,
> +		.step		= 1,
> +		.default_value	= DEF_RED,
> +	},
> +	{
> +		.id		= V4L2_CID_SATURATION,
> +		.type		= V4L2_CTRL_TYPE_INTEGER,
> +		.name		= "Saturation",
> +		.minimum	= 0,
> +		.maximum	= 0xf,
> +		.step		= 1,
> +		.default_value	= 0x8,
> +	},
> +	{
> +		.id		= V4L2_CID_HUE_AUTO,
> +		.type		= V4L2_CTRL_TYPE_BOOLEAN,
> +		.name		= "Auto Hue",
> +		.minimum	= 0,
> +		.maximum	= 1,
> +		.step		= 1,
> +		.default_value	= 1,
> +	},
> +	{
> +		.id		= V4L2_CID_HUE,
> +		.type		= V4L2_CTRL_TYPE_INTEGER,
> +		.name		= "Hue",
> +		.minimum	= 0,
> +		.maximum	= 0x1f,
> +		.step		= 1,
> +		.default_value	= DEF_HUE,
> +	},
> +	{
> +		.id		= V4L2_CID_BRIGHTNESS,
> +		.type		= V4L2_CTRL_TYPE_INTEGER,
> +		.name		= "Brightness",
> +		.minimum	= 0,
> +		.maximum	= 0xff,
> +		.step		= 1,
> +		.default_value	= 0x80,
> +	},
> +	{
> +		.id		= V4L2_CID_EXPOSURE_AUTO,
> +		.type		= V4L2_CTRL_TYPE_INTEGER,
> +		.name		= "AEC",
> +		.minimum	= 0,
> +		.maximum	= 3,
> +		.step		= 1,
> +		.default_value	= 0,
> +	},
> +	{
> +		.id		= V4L2_CID_EXPOSURE,
> +		.type		= V4L2_CTRL_TYPE_INTEGER,
> +		.name		= "Exposure",
> +		.minimum	= 0,
> +		.maximum	= 0xff,
> +		.step		= 1,
> +		.default_value	= DEF_AECH,
> +	},
> +	{
> +		.id		= V4L2_CID_GAMMA,
> +		.type		= V4L2_CTRL_TYPE_INTEGER,
> +		.name		= "Gamma",
> +		.minimum	= 0,
> +		.maximum	= 0xff,
> +		.step		= 1,
> +		.default_value	= 0x12,
> +	},
> +	{
> +		.id		= V4L2_CID_VFLIP,
> +		.type		= V4L2_CTRL_TYPE_BOOLEAN,
> +		.name		= "Flip Vertically",
> +		.minimum	= 0,
> +		.maximum	= 1,
> +		.step		= 1,
> +		.default_value	= 0,
> +	},
> +	{
> +		.id		= V4L2_CID_HFLIP,
> +		.type		= V4L2_CTRL_TYPE_BOOLEAN,
> +		.name		= "Flip Horizontally",
> +		.minimum	= 0,
> +		.maximum	= 1,
> +		.step		= 1,
> +		.default_value	= 0,
> +	},
> +};
> +
> +/* read a register */
> +static int ov6650_reg_read(struct i2c_client *client, u8 reg, u8 *val)
> +{
> +	int ret;
> +	u8 data = reg;
> +	struct i2c_msg msg = {
> +		.addr	= client->addr,
> +		.flags	= 0,
> +		.len	= 1,
> +		.buf	= &data,
> +	};
> +
> +	ret = i2c_transfer(client->adapter, &msg, 1);
> +	if (ret < 0)
> +		goto err;
> +
> +	msg.flags = I2C_M_RD;
> +	ret = i2c_transfer(client->adapter, &msg, 1);
> +	if (ret < 0)
> +		goto err;
> +
> +	*val = data;
> +	return 0;
> +
> +err:
> +	dev_err(&client->dev, "Failed reading register 0x%02x!\n", reg);
> +	return ret;
> +}
> +
> +/* write a register */
> +static int ov6650_reg_write(struct i2c_client *client, u8 reg, u8 val)
> +{
> +	int ret;
> +	u8 _val;
> +	unsigned char data[2] = { reg, val };
> +	struct i2c_msg msg = {
> +		.addr	= client->addr,
> +		.flags	= 0,
> +		.len	= 2,
> +		.buf	= data,
> +	};
> +
> +	ret = i2c_transfer(client->adapter, &msg, 1);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "Failed writing register 0x%02x!\n", reg);
> +		return ret;
> +	}
> +	msleep(1);

Hm, interesting... Is this really needed?

> +
> +	/* we have to read the register back ... no idea why, maybe HW bug */
> +	ret = ov6650_reg_read(client, reg, &_val);

You can also use "val" - it is not needed any more - and drop "_val."

> +	if (ret)
> +		dev_err(&client->dev,
> +			"Failed reading back register 0x%02x!\n", reg);
> +
> +	return 0;
> +}
> +
> +
> +/* Read a register, alter its bits, write it back */
> +static int ov6650_reg_rmw(struct i2c_client *client, u8 reg, u8 set, u8 mask)
> +{
> +	u8 val;
> +	int ret;
> +
> +	ret = ov6650_reg_read(client, reg, &val);
> +	if (ret) {
> +		dev_err(&client->dev,
> +			"[Read]-Modify-Write of register %02x failed!\n", reg);
> +		return val;

You mean "return ret"

> +	}
> +
> +	val &= ~mask;
> +	val |= set;
> +
> +	ret = ov6650_reg_write(client, reg, val);
> +	if (ret)
> +		dev_err(&client->dev,
> +			"Read-Modify-[Write] of register %02x failed!\n", reg);
> +
> +	return ret;
> +}
> +
> +/* Soft reset the camera. This has nothing to do with the RESET pin! */
> +static int ov6650_reset(struct i2c_client *client)
> +{
> +	int ret;
> +
> +	dev_dbg(&client->dev, "reset\n");
> +
> +	ret = ov6650_reg_rmw(client, REG_COMA, COMA_RESET, 0);
> +	if (ret)
> +		dev_err(&client->dev,
> +			"An error occured while entering soft reset!\n");
> +
> +	return ret;
> +}
> +
> +static struct ov6650 *to_ov6650(const struct i2c_client *client)
> +{
> +	return container_of(i2c_get_clientdata(client), struct ov6650, subdev);
> +}
> +
> +/* Start/Stop streaming from the device */
> +static int ov6650_s_stream(struct v4l2_subdev *sd, int enable)
> +{
> +	return 0;
> +}
> +
> +/* Alter bus settings on camera side */
> +static int ov6650_set_bus_param(struct soc_camera_device *icd,
> +				unsigned long flags)
> +{
> +	struct soc_camera_link *icl = to_soc_camera_link(icd);
> +	struct i2c_client *client = to_i2c_client(to_soc_camera_control(icd));
> +	int ret;
> +
> +	flags = soc_camera_apply_sensor_flags(icl, flags);
> +
> +	if (flags & SOCAM_PCLK_SAMPLE_RISING)
> +		ret = ov6650_reg_rmw(client, REG_COMJ, COMJ_PCLK_RISING, 0);
> +	else
> +		ret = ov6650_reg_rmw(client, REG_COMJ, 0, COMJ_PCLK_RISING);
> +	if (ret)
> +		goto out;
> +
> +	if (flags & SOCAM_HSYNC_ACTIVE_LOW)
> +		ret = ov6650_reg_rmw(client, REG_COMF, COMF_HREF_LOW, 0);
> +	else
> +		ret = ov6650_reg_rmw(client, REG_COMF, 0, COMF_HREF_LOW);
> +	if (ret)
> +		goto out;
> +
> +	if (flags & SOCAM_VSYNC_ACTIVE_HIGH)
> +		ret = ov6650_reg_rmw(client, REG_COMJ, COMJ_VSYNC_HIGH, 0);
> +	else
> +		ret = ov6650_reg_rmw(client, REG_COMJ, 0, COMJ_VSYNC_HIGH);
> +out:
> +	return ret;
> +}
> +
> +/* Request bus settings on camera side */
> +static unsigned long ov6650_query_bus_param(struct soc_camera_device *icd)
> +{
> +	struct soc_camera_link *icl = to_soc_camera_link(icd);
> +
> +	unsigned long flags = SOCAM_MASTER | \
> +		SOCAM_PCLK_SAMPLE_RISING | SOCAM_PCLK_SAMPLE_FALLING | \
> +		SOCAM_HSYNC_ACTIVE_HIGH | SOCAM_HSYNC_ACTIVE_LOW | \
> +		SOCAM_VSYNC_ACTIVE_HIGH | SOCAM_VSYNC_ACTIVE_LOW | \
> +		SOCAM_DATA_ACTIVE_HIGH | SOCAM_DATAWIDTH_8;
> +
> +	return soc_camera_apply_sensor_flags(icl, flags);
> +}
> +
> +/* Get status of additional camera capabilities */
> +static int ov6650_g_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl)
> +{
> +	struct i2c_client *client = sd->priv;
> +	struct ov6650 *priv = to_ov6650(client);
> +	uint8_t reg;
> +	int ret = 0;
> +
> +	switch (ctrl->id) {
> +	case V4L2_CID_AUTOGAIN:
> +		ctrl->value = priv->agc;
> +		break;
> +	case V4L2_CID_GAIN:
> +		if (priv->agc) {
> +			ret = ov6650_reg_read(client, REG_GAIN, &reg);
> +			ctrl->value = reg;
> +		} else {
> +			ctrl->value = priv->gain;
> +		}
> +		break;
> +	case V4L2_CID_AUTO_WHITE_BALANCE:
> +		ctrl->value = priv->awb;
> +		break;
> +	case V4L2_CID_BLUE_BALANCE:
> +		if (priv->awb) {
> +			ret = ov6650_reg_read(client, REG_BLUE, &reg);
> +			ctrl->value = reg;
> +		} else {
> +			ctrl->value = priv->blue;
> +		}
> +		break;
> +	case V4L2_CID_RED_BALANCE:
> +		if (priv->awb) {
> +			ret = ov6650_reg_read(client, REG_RED, &reg);
> +			ctrl->value = reg;
> +		} else {
> +			ctrl->value = priv->red;
> +		}
> +		break;
> +	case V4L2_CID_SATURATION:
> +		ctrl->value = priv->saturation;
> +		break;
> +	case V4L2_CID_HUE_AUTO:
> +		ctrl->value = priv->hue_auto;
> +		break;
> +	case V4L2_CID_HUE:
> +		if (priv->hue_auto) {
> +			ret = ov6650_reg_read(client, REG_HUE, &reg);
> +			ctrl->value = reg & 0x1f;
> +		} else {
> +			ctrl->value = priv->hue;
> +		}
> +		break;
> +	case V4L2_CID_BRIGHTNESS:
> +		ctrl->value = priv->brightness;
> +		break;
> +	case V4L2_CID_EXPOSURE_AUTO:
> +		ctrl->value = priv->aec;
> +		break;
> +	case V4L2_CID_EXPOSURE:
> +		if (priv->aec) {
> +			ret = ov6650_reg_read(client, REG_AECH, &reg);
> +			ctrl->value = reg;
> +		} else {
> +			ctrl->value = priv->exposure;
> +		}
> +		break;
> +	case V4L2_CID_GAMMA:
> +		ctrl->value = priv->gamma;
> +		break;
> +	case V4L2_CID_VFLIP:
> +		ctrl->value = priv->vflip;
> +		break;
> +	case V4L2_CID_HFLIP:
> +		ctrl->value = priv->hflip;
> +		break;
> +	}
> +	return ret;
> +}
> +
> +/* Set status of additional camera capabilities */
> +static int ov6650_s_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl)
> +{
> +	struct i2c_client *client = sd->priv;
> +	struct ov6650 *priv = to_ov6650(client);
> +	bool automatic;
> +	int ret = 0;
> +
> +	switch (ctrl->id) {
> +	case V4L2_CID_AUTOGAIN:
> +		if (ctrl->value) {
> +			ret = ov6650_reg_write(client, REG_GAIN, DEF_GAIN);
> +			if (ret)
> +				break;
> +			priv->gain = DEF_GAIN;
> +			ret = ov6650_reg_rmw(client, REG_COMB, COMB_AGC, 0);
> +		} else {
> +			ret = ov6650_reg_rmw(client, REG_COMB, 0, COMB_AGC);
> +		}
> +		if (ret)
> +			break;
> +		priv->agc = ctrl->value;
> +		break;
> +	case V4L2_CID_GAIN:
> +		ret = ov6650_reg_write(client, REG_GAIN, ctrl->value);
> +		if (ret)
> +			break;
> +		priv->gain = ctrl->value;
> +		automatic = (priv->gain == DEF_GAIN);
> +		if (automatic)
> +			ret = ov6650_reg_rmw(client, REG_COMB, COMB_AGC, 0);
> +		else
> +			ret = ov6650_reg_rmw(client, REG_COMB, 0, COMB_AGC);
> +		if (ret)
> +			break;
> +		priv->agc = automatic;

I wouldn't touch autogain here. You have V4L2_CID_AUTOGAIN for that. 
Setting gain to a value, that happens to be equal default, doesn't have to 
turn autogain on, does it?

> +		break;
> +	case V4L2_CID_AUTO_WHITE_BALANCE:
> +		if (ctrl->value) {
> +			ret = ov6650_reg_write(client, REG_BLUE, DEF_BLUE);
> +			if (ret)
> +				break;
> +			priv->blue = DEF_BLUE;
> +			ret = ov6650_reg_write(client, REG_RED, DEF_RED);
> +			if (ret)
> +				break;
> +			priv->red = DEF_RED;
> +			ret = ov6650_reg_rmw(client, REG_COMB, COMB_AWB, 0);
> +		} else {
> +			ret = ov6650_reg_rmw(client, REG_COMB, 0, COMB_AWB);
> +		}
> +		if (ret)
> +			break;
> +		priv->awb = ctrl->value;
> +		break;
> +	case V4L2_CID_BLUE_BALANCE:
> +		ret = ov6650_reg_write(client, REG_BLUE, ctrl->value);
> +		if (ret)
> +			break;
> +		priv->blue = ctrl->value;
> +		automatic = (priv->blue == DEF_BLUE &&
> +				priv->red == DEF_RED);
> +		if (automatic)
> +			ret = ov6650_reg_rmw(client, REG_COMB, COMB_AWB, 0);
> +		else
> +			ret = ov6650_reg_rmw(client, REG_COMB, 0, COMB_AWB);
> +		if (ret)
> +			break;
> +		priv->awb = automatic;
> +		break;
> +	case V4L2_CID_RED_BALANCE:
> +		ret = ov6650_reg_write(client, REG_RED, ctrl->value);
> +		if (ret)
> +			break;
> +		priv->red = ctrl->value;
> +		automatic = (priv->blue == DEF_BLUE &&
> +				priv->red == DEF_RED);
> +		if (automatic)
> +			ret = ov6650_reg_rmw(client, REG_COMB, COMB_AWB, 0);
> +		else
> +			ret = ov6650_reg_rmw(client, REG_COMB, 0, COMB_AWB);
> +		if (ret)
> +			break;
> +		priv->awb = automatic;

Same here, I wouldn't touch AWB in the above two controls. You have 
V4L2_CID_AUTO_WHITE_BALANCE for that.

> +		break;
> +	case V4L2_CID_SATURATION:
> +		ret = ov6650_reg_rmw(client, REG_SAT, SET_SAT(ctrl->value),
> +				SET_SAT(SAT_MASK));

With the proposed change it would look like

+		ret = ov6650_reg_rmw(client, REG_SAT, SET_SAT(ctrl->value),
+				SAT_MASK);

which I personally find a bit more pleasant to the eyes;)

> +		if (ret)
> +			break;
> +		priv->saturation = ctrl->value;
> +		break;
> +	case V4L2_CID_HUE_AUTO:
> +		if (ctrl->value) {
> +			ret = ov6650_reg_rmw(client, REG_HUE,
> +					SET_HUE(DEF_HUE), SET_HUE(HUE_MASK));
> +			if (ret)
> +				break;
> +			priv->hue = DEF_HUE;
> +		} else {
> +			ret = ov6650_reg_rmw(client, REG_HUE, HUE_EN, 0);
> +		}
> +		if (ret)
> +			break;
> +		priv->hue_auto = ctrl->value;

Hm, sorry, don't understand. If the user sets auto-hue to ON, you set the 
hue enable bit and hue value to default. If the user sets auto-hue to OFF, 
you just set the hue enable bit on and don't change the value. Does ov6650 
actually support auto-hue?

> +		break;
> +	case V4L2_CID_HUE:
> +		ret = ov6650_reg_rmw(client, REG_HUE, SET_HUE(ctrl->value),
> +				SET_HUE(HUE_MASK));
> +		if (ret)
> +			break;
> +		priv->hue = ctrl->value;
> +		priv->hue_auto = (priv->hue == DEF_HUE);

Here it seems like in order to adjust hue you always have to set the 
enable bit. Again, I wouldn't touch hue_auto here - default and auto are 
different things.

> +		break;
> +	case V4L2_CID_BRIGHTNESS:
> +		ret = ov6650_reg_write(client, REG_BRT, ctrl->value);
> +		if (ret)
> +			break;
> +		priv->brightness = ctrl->value;
> +		break;
> +	case V4L2_CID_EXPOSURE_AUTO:
> +		switch (ctrl->value) {
> +		case V4L2_EXPOSURE_AUTO:
> +			ret = ov6650_reg_write(client, REG_AECH, DEF_AECH);

Is this a requirement for auto-exposure, that you have to set the (analog 
manual) exposure to the default value?

> +			if (ret)
> +				break;
> +			priv->exposure = DEF_AECH;
> +			ret = ov6650_reg_rmw(client, REG_COMB, COMB_AEC, 0);
> +			break;
> +		default:
> +			ret = ov6650_reg_rmw(client, REG_COMB, 0, COMB_AEC);
> +			break;
> +		}
> +		if (ret)
> +			break;
> +		priv->aec = ctrl->value;
> +		break;
> +	case V4L2_CID_EXPOSURE:
> +		ret = ov6650_reg_write(client, REG_AECH, ctrl->value);
> +		if (ret)
> +			break;
> +		priv->exposure = ctrl->value;
> +		automatic = (priv->exposure == DEF_AECH);
> +		if (automatic)
> +			ret = ov6650_reg_rmw(client, REG_COMB, COMB_AEC, 0);
> +		else
> +			ret = ov6650_reg_rmw(client, REG_COMB, 0, COMB_AEC);
> +		if (ret)
> +			break;
> +		priv->aec = automatic ? V4L2_EXPOSURE_AUTO :
> +				V4L2_EXPOSURE_MANUAL;

Again - don't see why you need to touch the auto setting here.

> +		break;
> +	case V4L2_CID_GAMMA:
> +		ret = ov6650_reg_write(client, REG_GAM1, ctrl->value);
> +		if (ret)
> +			break;
> +		priv->gamma = ctrl->value;
> +		break;
> +	case V4L2_CID_VFLIP:
> +		if (ctrl->value)
> +			ret = ov6650_reg_rmw(client, REG_COMB,
> +							COMB_FLIP_V, 0);
> +		else
> +			ret = ov6650_reg_rmw(client, REG_COMB,
> +							0, COMB_FLIP_V);
> +		if (ret)
> +			break;
> +		priv->vflip = ctrl->value;
> +		break;
> +	case V4L2_CID_HFLIP:
> +		if (ctrl->value)
> +			ret = ov6650_reg_rmw(client, REG_COMB,
> +							COMB_FLIP_H, 0);
> +		else
> +			ret = ov6650_reg_rmw(client, REG_COMB,
> +							0, COMB_FLIP_H);
> +		if (ret)
> +			break;
> +		priv->hflip = ctrl->value;
> +		break;
> +	}
> +
> +	return ret;
> +}
> +
> +/* Get chip identification */
> +static int ov6650_g_chip_ident(struct v4l2_subdev *sd,
> +				struct v4l2_dbg_chip_ident *id)
> +{
> +	id->ident	= V4L2_IDENT_OV6650;
> +	id->revision	= 0;
> +
> +	return 0;
> +}
> +
> +#ifdef CONFIG_VIDEO_ADV_DEBUG
> +static int ov6650_get_register(struct v4l2_subdev *sd,
> +				struct v4l2_dbg_register *reg)
> +{
> +	struct i2c_client *client = sd->priv;
> +	int ret;
> +	u8 val;
> +
> +	if (reg->reg & ~0xff)
> +		return -EINVAL;
> +
> +	reg->size = 1;
> +
> +	ret = ov6650_reg_read(client, reg->reg, &val);
> +	if (ret)
> +		return ret;
> +
> +	reg->val = (__u64)val;
> +
> +	return 0;
> +}
> +
> +static int ov6650_set_register(struct v4l2_subdev *sd,
> +				struct v4l2_dbg_register *reg)
> +{
> +	struct i2c_client *client = sd->priv;
> +
> +	if (reg->reg & ~0xff || reg->val & ~0xff)
> +		return -EINVAL;
> +
> +	return ov6650_reg_write(client, reg->reg, reg->val);
> +}
> +#endif
> +
> +/* select nearest higher resolution for capture */
> +static void ov6650_res_roundup(u32 *width, u32 *height)
> +{
> +	int i;
> +	enum { QCIF, CIF };
> +	int res_x[] = { 176, 352 };
> +	int res_y[] = { 144, 288 };
> +
> +	for (i = 0; i < ARRAY_SIZE(res_x); i++) {
> +		if (res_x[i] >= *width && res_y[i] >= *height) {
> +			*width = res_x[i];
> +			*height = res_y[i];
> +			return;
> +		}
> +	}
> +
> +	*width = res_x[CIF];
> +	*height = res_y[CIF];
> +}

This can be replaced by a version of

http://www.spinics.net/lists/linux-media/msg21893.html

when it is fixed and accepted;) I'll try to send an updated version of 
that patch tomorrow.

> +
> +/* program default register values */
> +static int ov6650_prog_dflt(struct i2c_client *client)
> +{
> +	int i, ret;
> +
> +	dev_dbg(&client->dev, "reinitializing\n");
> +
> +	for (i = 0; i < ARRAY_SIZE(ov6650_regs_dflt); i++) {
> +		ret = ov6650_reg_write(client, ov6650_regs_dflt[i].reg,
> +						ov6650_regs_dflt[i].val);
> +		if (ret)
> +			return ret;
> +	}

Hm, please, don't. I generally don't like such register - value array 
magic for a number of reasons, and in your case it's just one (!) register 
write operation - please, remove this array and just write the register 
explicitly. You also don't need DEF_COMA - writing an explicit "0" and 
adding a comment - "clear all flags, including reset" would be perfect!

> +
> +	return 0;
> +}
> +
> +/* set the format we will capture in */
> +static int ov6650_s_fmt(struct v4l2_subdev *sd,
> +			struct v4l2_mbus_framefmt *mf)
> +{
> +	struct i2c_client *client = sd->priv;
> +	struct soc_camera_device *icd	= client->dev.platform_data;
> +	struct soc_camera_sense *sense = icd->sense;
> +	struct ov6650 *priv = to_ov6650(client);
> +	enum v4l2_colorspace cspace;
> +	enum v4l2_mbus_pixelcode code = mf->code;
> +	unsigned long pclk;
> +	u8 coma_set = 0, coma_mask = 0, coml_set = 0, coml_mask = 0, clkrc;
> +	int ret;
> +
> +	/* select color matrix configuration for given color encoding */
> +	switch (code) {
> +	case V4L2_MBUS_FMT_GREY8_1X8:
> +		dev_dbg(&client->dev, "pixel format GREY8_1X8\n");
> +		coma_set |= COMA_BW;
> +		coma_mask |= COMA_RGB | COMA_WORD_SWAP | COMA_BYTE_SWAP;
> +		coml_mask |= COML_ONE_CHANNEL;
> +		cspace = V4L2_COLORSPACE_JPEG;
> +		priv->pclk_max = 4000000;
> +		break;
> +	case V4L2_MBUS_FMT_YUYV8_2X8_LE:
> +		dev_dbg(&client->dev, "pixel format YUYV8_2X8_LE\n");
> +		coma_set |= COMA_WORD_SWAP;
> +		coma_mask |= COMA_RGB | COMA_BW | COMA_BYTE_SWAP;
> +		goto yuv;

Well, this doesn't look critical to me, i.e., eventually I would accept 
this, but, as you know, goto's in the kernel are (almost) only used for 
failure cases, besides, what makes this use even less pretty, this is a 
goto into a switch statement... I would set a "yuv = 1" variable instead 
of goto's, and use a "if (yuv) after the switch.

> +	case V4L2_MBUS_FMT_YVYU8_2X8_LE:
> +		dev_dbg(&client->dev, "pixel format YVYU8_2X8_LE (untested)\n");
> +		coma_mask |= COMA_RGB | COMA_BW | COMA_WORD_SWAP |
> +				COMA_BYTE_SWAP;
> +		goto yuv;
> +	case V4L2_MBUS_FMT_YUYV8_2X8_BE:
> +		dev_dbg(&client->dev, "pixel format YUYV8_2X8_BE\n");
> +		if (mf->width == W_CIF) {
> +			coma_set |= COMA_BYTE_SWAP | COMA_WORD_SWAP;
> +			coma_mask |= COMA_RGB | COMA_BW;
> +		} else {
> +			coma_set |= COMA_BYTE_SWAP;
> +			coma_mask |= COMA_RGB | COMA_BW | COMA_WORD_SWAP;
> +		}
> +		goto yuv;
> +	case V4L2_MBUS_FMT_YVYU8_2X8_BE:
> +		dev_dbg(&client->dev, "pixel format YVYU8_2X8_BE (untested)\n");
> +		if (mf->width == W_CIF) {
> +			coma_set |= COMA_BYTE_SWAP;
> +			coma_mask |= COMA_RGB | COMA_BW | COMA_WORD_SWAP;
> +		} else {
> +			coma_set |= COMA_BYTE_SWAP | COMA_WORD_SWAP;
> +			coma_mask |= COMA_RGB | COMA_BW;
> +		}
> +yuv:
> +		coml_set |= COML_ONE_CHANNEL;
> +		cspace = V4L2_COLORSPACE_JPEG;
> +		priv->pclk_max = 8000000;
> +		break;
> +	case V4L2_MBUS_FMT_SBGGR8_1X8:
> +		dev_dbg(&client->dev, "pixel format SBGGR8_1X8 (untested)\n");
> +		coma_set |= COMA_RAW_RGB | COMA_RGB;
> +		coma_mask |= COMA_BW | COMA_BYTE_SWAP | COMA_WORD_SWAP;
> +		coml_mask |= COML_ONE_CHANNEL;
> +		cspace = V4L2_COLORSPACE_SRGB;
> +		priv->pclk_max = 4000000;
> +		break;
> +	default:
> +		dev_err(&client->dev, "Pixel format not handled : %x\n", code);
> +		return -EINVAL;
> +	}
> +
> +	/* select register configuration for given resolution */
> +	ov6650_res_roundup(&mf->width, &mf->height);
> +
> +	switch (mf->width) {
> +	case W_QCIF:
> +		dev_dbg(&client->dev, "resolution QCIF\n");
> +		priv->qcif = 1;
> +		coma_set |= COMA_QCIF;
> +		priv->pclk_max /= 2;
> +		break;
> +	case W_CIF:
> +		dev_dbg(&client->dev, "resolution CIF\n");
> +		priv->qcif = 0;
> +		coma_mask |= COMA_QCIF;
> +		break;
> +	default:
> +		dev_err(&client->dev, "unspported resolution!\n");
> +		return -EINVAL;
> +	}
> +
> +	if (priv->timeperframe.numerator && priv->timeperframe.denominator)
> +		pclk = priv->pclk_max * priv->timeperframe.denominator /
> +				(FRAME_RATE_MAX * priv->timeperframe.numerator);
> +	else
> +		pclk = priv->pclk_max;
> +
> +	if (sense) {
> +		if (sense->master_clock == 8000000) {
> +			dev_dbg(&client->dev, "8MHz input clock\n");
> +			clkrc = CLKRC_6MHz;
> +		} else if (sense->master_clock == 12000000) {
> +			dev_dbg(&client->dev, "12MHz input clock\n");
> +			clkrc = CLKRC_12MHz;
> +		} else if (sense->master_clock == 16000000) {
> +			dev_dbg(&client->dev, "16MHz input clock\n");
> +			clkrc = CLKRC_16MHz;
> +		} else if (sense->master_clock == 24000000) {
> +			dev_dbg(&client->dev, "24MHz input clock\n");
> +			clkrc = CLKRC_24MHz;
> +		} else {
> +			dev_err(&client->dev,
> +				"unspported input clock, check platform data"
> +				"\n");
> +			return -EINVAL;
> +		}
> +		priv->pclk_limit = sense->pixel_clock_max;
> +		if (priv->pclk_limit &&
> +				(priv->pclk_limit < pclk))

This can go on one line.

> +			pclk = priv->pclk_limit;
> +	} else {
> +		priv->pclk_limit = 0;
> +		clkrc = 0xc0;
> +		dev_dbg(&client->dev, "using default 24MHz input clock\n");
> +	}
> +
> +	clkrc |= (priv->pclk_max - 1) / pclk;
> +	pclk = priv->pclk_max / GET_CLKRC_DIV(clkrc);

This would look better as

	clkrc_div = (priv->pclk_max - 1) / pclk;
	clkrc |= clkrc_div;
	pclk = priv->pclk_max / clkrc_div;

> +	dev_dbg(&client->dev, "pixel clock divider: %ld.%ld\n",
> +			sense->master_clock / pclk,
> +			10 * sense->master_clock % pclk / pclk);
> +
> +	ov6650_reset(client);
> +
> +	ret = ov6650_prog_dflt(client);
> +	if (ret)
> +		return ret;
> +
> +

Superfluous empty line;)

> +	ret = ov6650_reg_rmw(client, REG_COMA, coma_set, coma_mask);
> +	if (!ret)
> +		ret = ov6650_reg_write(client, REG_CLKRC, clkrc);
> +	if (!ret)
> +		ret = ov6650_reg_rmw(client, REG_COML, coml_set, coml_mask);
> +
> +	if (!ret) {
> +		mf->code	= code;
> +		mf->colorspace	= cspace;
> +	}
> +
> +	return ret;
> +}
> +
> +static int ov6650_try_fmt(struct v4l2_subdev *sd,
> +			  struct v4l2_mbus_framefmt *mf)
> +{
> +	ov6650_res_roundup(&mf->width, &mf->height);
> +
> +	mf->field = V4L2_FIELD_NONE;
> +
> +	switch (mf->code) {
> +	case V4L2_MBUS_FMT_Y10_1X10:
> +		mf->code = V4L2_MBUS_FMT_GREY8_1X8;
> +	case V4L2_MBUS_FMT_GREY8_1X8:
> +	case V4L2_MBUS_FMT_YVYU8_2X8_LE:
> +	case V4L2_MBUS_FMT_YUYV8_2X8_LE:
> +	case V4L2_MBUS_FMT_YVYU8_2X8_BE:
> +	case V4L2_MBUS_FMT_YUYV8_2X8_BE:
> +		mf->colorspace = V4L2_COLORSPACE_JPEG;
> +		break;
> +	default:
> +		mf->code = V4L2_MBUS_FMT_SBGGR8_1X8;
> +	case V4L2_MBUS_FMT_SBGGR8_1X8:
> +		mf->colorspace = V4L2_COLORSPACE_SRGB;
> +		break;
> +	}
> +
> +	return 0;
> +}
> +
> +static int ov6650_enum_fmt(struct v4l2_subdev *sd, unsigned int index,
> +			   enum v4l2_mbus_pixelcode *code)
> +{
> +	if ((unsigned int)index >= ARRAY_SIZE(ov6650_codes))
> +		return -EINVAL;
> +
> +	*code = ov6650_codes[index];
> +	return 0;
> +}
> +
> +static int ov6650_cropcap(struct v4l2_subdev *sd, struct v4l2_cropcap *a)
> +{
> +	struct i2c_client *client = sd->priv;
> +	struct ov6650 *priv = to_ov6650(client);
> +	int shift = !priv->qcif;
> +
> +	if (a->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
> +		return -EINVAL;
> +
> +	/* Crop limits depend on selected frame format (CIF/QCIF) */
> +	a->bounds.left			= DEF_HSTRT << shift;
> +	a->bounds.top			= DEF_VSTRT << shift;
> +	a->bounds.width			= W_QCIF << shift;
> +	a->bounds.height		= H_QCIF << shift;
> +	/* REVISIT: should defrect provide actual or default geometry? */

default

> +	a->defrect			= a->bounds;
> +	a->pixelaspect.numerator	= 1;
> +	a->pixelaspect.denominator	= 1;
> +
> +	return 0;
> +}
> +
> +static int ov6650_g_crop(struct v4l2_subdev *sd, struct v4l2_crop *a)
> +{
> +	struct i2c_client *client = sd->priv;
> +	struct ov6650 *priv = to_ov6650(client);
> +	struct v4l2_rect *rect = &a->c;
> +	int shift = !priv->qcif;
> +	u8 hstrt, vstrt, hstop, vstop;
> +	int ret;
> +
> +	if (a->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
> +		return -EINVAL;
> +
> +	ret = ov6650_reg_read(client, REG_HSTRT, &hstrt);
> +	if (!ret)
> +		ret = ov6650_reg_read(client, REG_HSTOP, &hstop);
> +	if (!ret)
> +		ret = ov6650_reg_read(client, REG_VSTRT, &vstrt);
> +	if (!ret)
> +		ret = ov6650_reg_read(client, REG_VSTOP, &vstop);
> +
> +	if (!ret) {
> +		rect->left	= hstrt << shift;
> +		rect->top	= vstrt << shift;
> +		rect->width	= (hstop - hstrt) << shift;
> +		rect->height	= (vstop - vstrt) << shift;
> +	}
> +
> +	return ret;
> +}
> +
> +static int ov6650_s_crop(struct v4l2_subdev *sd, struct v4l2_crop *a)
> +{
> +	struct i2c_client *client = sd->priv;
> +	struct ov6650 *priv = to_ov6650(client);
> +	struct v4l2_rect *rect = &a->c;
> +	int shift = !priv->qcif;
> +	u8 hstrt, vstrt, hstop, vstop;
> +	int ret;
> +
> +	if (a->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
> +		return -EINVAL;
> +
> +	hstrt = rect->left >> shift;
> +	vstrt = rect->top >> shift;
> +	hstop = hstrt + (rect->width >> shift);
> +	vstop = vstrt + (rect->height >> shift);
> +
> +	if ((hstop > DEF_HSTOP) || (vstop > DEF_VSTOP)) {
> +		dev_err(&client->dev, "Invalid window geometry!\n");
> +		return -EINVAL;
> +	}
> +
> +	ret = ov6650_reg_write(client, REG_HSTRT, hstrt);
> +	if (!ret)
> +		ret = ov6650_reg_write(client, REG_HSTOP, hstop);
> +	if (!ret)
> +		ret = ov6650_reg_write(client, REG_VSTRT, vstrt);
> +	if (!ret)
> +		ret = ov6650_reg_write(client, REG_VSTOP, vstop);

Are cropping and scaling on this camera absolutely independent? I.e., you 
can set any output format (CIF or QCIF) and it will just scale whatever 
rectangle has been configured? And the other way round - you set arbitrary 
cropping and output format stays the same?

> +
> +	return ret;
> +}
> +
> +static int ov6650_g_parm(struct v4l2_subdev *sd, struct v4l2_streamparm *parms)
> +{
> +	struct i2c_client *client = sd->priv;
> +	struct v4l2_captureparm *cp = &parms->parm.capture;
> +	u8 clkrc;
> +	int ret;
> +
> +	if (parms->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
> +		return -EINVAL;
> +
> +	ret = ov6650_reg_read(client, REG_CLKRC, &clkrc);
> +	if (ret < 0)
> +		return ret;
> +
> +	memset(cp, 0, sizeof(struct v4l2_captureparm));
> +	cp->capability = V4L2_CAP_TIMEPERFRAME;
> +	cp->timeperframe.numerator = GET_CLKRC_DIV(clkrc);
> +	cp->timeperframe.denominator = FRAME_RATE_MAX;
> +
> +	dev_dbg(&client->dev, "Frame interval: %u/%u\n",
> +		cp->timeperframe.numerator, cp->timeperframe.denominator);
> +
> +	return 0;
> +}
> +
> +static int ov6650_s_parm(struct v4l2_subdev *sd, struct v4l2_streamparm *parms)
> +{
> +	struct i2c_client *client = sd->priv;
> +	struct ov6650 *priv = to_ov6650(client);
> +	struct v4l2_captureparm *cp = &parms->parm.capture;
> +	struct v4l2_fract *tpf = &cp->timeperframe;
> +	int div, ret;
> +
> +	if (parms->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
> +		return -EINVAL;
> +
> +	if (cp->extendedmode != 0)
> +		return -EINVAL;
> +
> +	if (tpf->numerator == 0 || tpf->denominator == 0)
> +		div = 1;  /* Reset to full rate */
> +	else
> +		div = (tpf->numerator * FRAME_RATE_MAX) / tpf->denominator;
> +
> +	if (div == 0)
> +		div = 1;
> +	else if (div > CLKRC_DIV_MASK + 1)
> +		div = CLKRC_DIV_MASK + 1;
> +
> +	if (priv->pclk_max && priv->pclk_limit) {
> +		ret = (priv->pclk_max - 1) / priv->pclk_limit;
> +		if (div < ret)
> +			div = ret;
> +	}
> +
> +	ret = ov6650_reg_rmw(client, REG_CLKRC, div - 1, CLKRC_DIV_MASK);
> +	if (!ret) {
> +		priv->timeperframe.numerator = tpf->numerator = FRAME_RATE_MAX;
> +		priv->timeperframe.denominator = tpf->denominator = div;
> +	}
> +
> +	return ret;
> +}
> +
> +static int ov6650_video_probe(struct soc_camera_device *icd,
> +				struct i2c_client *client)
> +{
> +	u8		pidh, pidl, midh, midl;
> +	int		ret = 0;
> +
> +	/*
> +	 * check and show product ID and manufacturer ID
> +	 */
> +	ret = ov6650_reg_read(client, REG_PIDH, &pidh);
> +	if (!ret)
> +		ret = ov6650_reg_read(client, REG_PIDL, &pidl);
> +	if (!ret)
> +		ret = ov6650_reg_read(client, REG_MIDH, &midh);
> +	if (!ret)
> +		ret = ov6650_reg_read(client, REG_MIDL, &midl);
> +
> +	if (ret)
> +		goto err;
> +
> +	if ((pidh != OV6650_PIDH) || (pidl != OV6650_PIDL)) {
> +		dev_err(&client->dev, "Product ID error %x:%x\n", pidh, pidl);
> +		ret = -ENODEV;
> +		goto err;
> +	}
> +
> +	dev_info(&client->dev, "ov6650 Product ID %0x:%0x Manufacturer ID %x:%x"
> +			"\n", pidh, pidl, midh, midl);
> +
> +err:
> +	return ret;
> +}
> +
> +static struct soc_camera_ops ov6650_ops = {
> +	.set_bus_param		= ov6650_set_bus_param,
> +	.query_bus_param	= ov6650_query_bus_param,
> +	.controls		= ov6650_controls,
> +	.num_controls		= ARRAY_SIZE(ov6650_controls),
> +};
> +
> +static struct v4l2_subdev_core_ops ov6650_core_ops = {
> +	.g_ctrl			= ov6650_g_ctrl,
> +	.s_ctrl			= ov6650_s_ctrl,
> +	.g_chip_ident		= ov6650_g_chip_ident,
> +#ifdef CONFIG_VIDEO_ADV_DEBUG
> +	.g_register		= ov6650_get_register,
> +	.s_register		= ov6650_set_register,
> +#endif
> +

Superfluous empty line

> +};
> +
> +static struct v4l2_subdev_video_ops ov6650_video_ops = {
> +	.s_stream	= ov6650_s_stream,
> +	.s_mbus_fmt	= ov6650_s_fmt,
> +	.try_mbus_fmt	= ov6650_try_fmt,

Please, implement.g_mbus_fmt.

> +	.enum_mbus_fmt	= ov6650_enum_fmt,
> +	.cropcap	= ov6650_cropcap,
> +	.g_crop		= ov6650_g_crop,
> +	.s_crop		= ov6650_s_crop,
> +	.g_parm		= ov6650_g_parm,
> +	.s_parm		= ov6650_s_parm,
> +

Superfluous empty line

> +};
> +
> +static struct v4l2_subdev_ops ov6650_subdev_ops = {
> +	.core	= &ov6650_core_ops,
> +	.video	= &ov6650_video_ops,
> +};
> +
> +/*
> + * i2c_driver function
> + */
> +static int ov6650_probe(struct i2c_client *client,
> +			const struct i2c_device_id *did)
> +{
> +	struct ov6650 *priv;
> +	struct soc_camera_device *icd	= client->dev.platform_data;

Nothing to align here, a space before "=" would suffice;)

> +	struct soc_camera_link *icl;
> +	int ret;
> +
> +	if (!icd) {
> +		dev_err(&client->dev, "Missing soc-camera data!\n");
> +		return -EINVAL;
> +	}
> +
> +	icl = to_soc_camera_link(icd);
> +	if (!icl) {
> +		dev_err(&client->dev, "Missing platform_data for driver\n");
> +		return -EINVAL;
> +	}
> +
> +	priv = kzalloc(sizeof(struct ov6650), GFP_KERNEL);
> +	if (!priv) {
> +		dev_err(&client->dev,
> +			"Failed to allocate memory for private data!\n");
> +		return -ENOMEM;
> +	}
> +
> +	v4l2_i2c_subdev_init(&priv->subdev, client, &ov6650_subdev_ops);
> +
> +	icd->ops	= &ov6650_ops;

A matter of taste, eventually, but I'd use a space.

> +
> +	ret = ov6650_video_probe(icd, client);
> +
> +	if (ret) {
> +		icd->ops = NULL;
> +		i2c_set_clientdata(client, NULL);
> +		kfree(priv);
> +	}
> +
> +	return ret;
> +}
> +
> +static int ov6650_remove(struct i2c_client *client)
> +{
> +	struct ov6650 *priv = to_ov6650(client);
> +
> +	i2c_set_clientdata(client, NULL);
> +	kfree(priv);
> +	return 0;
> +}
> +
> +static const struct i2c_device_id ov6650_id[] = {
> +	{ "ov6650", 0 },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(i2c, ov6650_id);
> +
> +static struct i2c_driver ov6650_i2c_driver = {
> +	.driver = {
> +		.name = "ov6650",
> +	},
> +	.probe    = ov6650_probe,
> +	.remove   = ov6650_remove,
> +	.id_table = ov6650_id,
> +};
> +
> +static int __init ov6650_module_init(void)
> +{
> +	return i2c_add_driver(&ov6650_i2c_driver);
> +}
> +
> +static void __exit ov6650_module_exit(void)
> +{
> +	i2c_del_driver(&ov6650_i2c_driver);
> +}
> +
> +module_init(ov6650_module_init);
> +module_exit(ov6650_module_exit);
> +
> +MODULE_DESCRIPTION("SoC Camera driver for OmniVision OV6650");
> +MODULE_AUTHOR("Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>");
> +MODULE_LICENSE("GPL v2");
> --- linux-2.6.35-rc3.orig/include/media/v4l2-chip-ident.h	2010-06-26 15:56:15.000000000 +0200
> +++ linux-2.6.35-rc3/include/media/v4l2-chip-ident.h	2010-06-26 17:28:09.000000000 +0200
> @@ -70,6 +70,7 @@ enum {
>  	V4L2_IDENT_OV9655 = 255,
>  	V4L2_IDENT_SOI968 = 256,
>  	V4L2_IDENT_OV9640 = 257,
> +	V4L2_IDENT_OV6650 = 258,
>  
>  	/* module saa7146: reserved range 300-309 */
>  	V4L2_IDENT_SAA7146 = 300,
> 

Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/

Re: [RFC] [PATCH 3/6] SoC Camera: add driver for OV6650 sensor

[Janusz Krzysztofik]

Hi Guennadi,
Thanks for your review time.

Sunday 22 August 2010 18:40:13 Guennadi Liakhovetski wrote:
> On Sun, 18 Jul 2010, Janusz Krzysztofik wrote:
> > This patch provides a V4L2 SoC Camera driver for OV6650 camera sensor,
> > found on OMAP1 SoC based Amstrad Delta videophone.
>
> Have you also had a look at drivers/media/video/gspca/sonixb.c - in also
> supports ov6650 among other sensors.

Yes, I have, but given up for now since:
1. the gspca seems using the sensor in "Bayer 8 BGGR" mode only, which I was 
   not even able to select using mplayer to test my drivers with,
2. not all settings used there are clear for me, so I've decided to revisit 
   them later, when I first get a stable, even if not perfect, working driver 
   version accepted, instead of following them blindly.

> > Since I have no experience with camera sensors, and the sensor
> > documentation I was able to find was not very comprehensive, I left most
> > settings at their default (reset) values, except for:
> > - those required for proper mediabus parameters and picture format setup,
> > - those used by controls.
> > Resulting picture quality is far from perfect, but better than nothing.
> >
...
> > --- linux-2.6.35-rc3.orig/drivers/media/video/ov6650.c	1970-01-01 
01:00:00.000000000 +0100 
> > +++ linux-2.6.35-rc3/drivers/media/video/ov6650.c	2010-07-18 
02:06:22.000000000 +0200 
> > @@ -0,0 +1,1336 @@ 
> > +/*
> > + * V4L2 SoC Camera driver for OmniVision OV6650 Camera Sensor
> > + *
> > + * Copyright (C) 2010 Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
> > + *
> > + * Based on OmniVision OV96xx Camera Driver
> > + * Copyright (C) 2009 Marek Vasut <marek.vasut@gmail.com>
> > + *
> > + * Based on ov772x camera driver:
> > + * Copyright (C) 2008 Renesas Solutions Corp.
> > + * Kuninori Morimoto <morimoto.kuninori@renesas.com>
> > + *
> > + * Based on ov7670 and soc_camera_platform driver,
> > + * Copyright 2006-7 Jonathan Corbet <corbet@lwn.net>
> > + * Copyright (C) 2008 Magnus Damm
> > + * Copyright (C) 2008, Guennadi Liakhovetski <kernel@pengutronix.de>
> > + *
> > + * Hardware specific bits initialy based on former work by Matt Callow
> > + * drivers/media/video/omap/sensor_ov6650.c
> > + * Copyright (C) 2006 Matt Callow
> > + *
> > + * This program is free software; you can redistribute it and/or modify
> > + * it under the terms of the GNU General Public License version 2 as
> > + * published by the Free Software Foundation.
> > + */
> > +
> > +#include <linux/i2c.h>
> > +#include <linux/slab.h>
> > +#include <linux/delay.h>
> > +#include <media/v4l2-chip-ident.h>
> > +#include <media/soc_camera.h>
>
> Please, sort headers alphabetically (media/ and linux/ separately, of
> course).

OK.

> > +
> > +
> > +/* Register definitions */
> > +#define	REG_GAIN		0x00	/* range 00 - 3F */
> > +#define	REG_BLUE		0x01
> > +#define	REG_RED			0x02
> > +#define	REG_SAT			0x03	/* [7:4] saturation [0:3] reserved */
> > +#define	REG_HUE			0x04	/* [7:6] rsrvd [5] hue en [4:0] hue */
> > +
> > +#define	REG_BRT			0x06
> > +
> > +#define	REG_PIDH		0x0a
> > +#define	REG_PIDL		0x0b
> > +
> > +#define	REG_AECH		0x10
> > +#define	REG_CLKRC		0x11	/* Data Format and Internal Clock */
> > +					/* [7:6] Input system clock (MHz)*/
> > +					/*   00=8, 01=12, 10=16, 11=24 */
> > +					/* [5:0]: Internal Clock Pre-Scaler */
> > +#define	REG_COMA		0x12	/* [7] Reset */
> > +#define	REG_COMB		0x13
> > +#define	REG_COMC		0x14
> > +#define	REG_COMD		0x15
> > +#define REG_COML		0x16
>
> You used TAB in most defines and a space in this one and a few ones below.
> Please, use the same for all (I personally would just use a space).

Agree.

...
> > +
> > +#define NUM_REGS		(REG_BMCO + 1)
>
> NUM_REGS is unused, don't need to define it.

OK.

...
> > +#define SAT_SHIFT		4
> > +#define SAT_MASK		0xf
> > +#define SET_SAT(x)		(((x) & SAT_MASK) << SAT_SHIFT)
>
> Nitpicking, but I would
>
> +#define SAT_SHIFT		4
> +#define SAT_MASK		0xf0
> +#define SET_SAT(x)		(((x) << SAT_SHIFT) & SAT_MASK)
>
> Advantage: your SAT_MASK is already correctly shifted, so, you don't have
> to you SET_SAT(SAT_MASK) to get to the register value.

You're right.

> > +
> > +#define HUE_EN			BIT(5)
>
> You have to #include <linux/bitops.h> for the BIT() macro

OK.

...
> > +/* write a register */
> > +static int ov6650_reg_write(struct i2c_client *client, u8 reg, u8 val)
> > +{
> > +	int ret;
> > +	u8 _val;
> > +	unsigned char data[2] = { reg, val };
> > +	struct i2c_msg msg = {
> > +		.addr	= client->addr,
> > +		.flags	= 0,
> > +		.len	= 2,
> > +		.buf	= data,
> > +	};
> > +
> > +	ret = i2c_transfer(client->adapter, &msg, 1);
> > +	if (ret < 0) {
> > +		dev_err(&client->dev, "Failed writing register 0x%02x!\n", reg);
> > +		return ret;
> > +	}
> > +	msleep(1);
>
> Hm, interesting... Is this really needed?

If you mean msleep(1) - yes, the sensor didn't work correctly for me without 
that msleep().

I you mean reading the register back - I've not tried without, will do.

> > +
> > +	/* we have to read the register back ... no idea why, maybe HW bug */
> > +	ret = ov6650_reg_read(client, reg, &_val);
>
> You can also use "val" - it is not needed any more - and drop "_val."

Will do.

> > +	if (ret)
> > +		dev_err(&client->dev,
> > +			"Failed reading back register 0x%02x!\n", reg);
> > +
> > +	return 0;
> > +}
> > +
> > +
> > +/* Read a register, alter its bits, write it back */
> > +static int ov6650_reg_rmw(struct i2c_client *client, u8 reg, u8 set, u8
> > mask) +{
> > +	u8 val;
> > +	int ret;
> > +
> > +	ret = ov6650_reg_read(client, reg, &val);
> > +	if (ret) {
> > +		dev_err(&client->dev,
> > +			"[Read]-Modify-Write of register %02x failed!\n", reg);
> > +		return val;
>
> You mean "return ret"

Yes, thanks.

> > +	}
> > +
> > +	val &= ~mask;
> > +	val |= set;
> > +
> > +	ret = ov6650_reg_write(client, reg, val);
> > +	if (ret)
> > +		dev_err(&client->dev,
> > +			"Read-Modify-[Write] of register %02x failed!\n", reg);
> > +
> > +	return ret;
> > +}
> > +
> > +/* Soft reset the camera. This has nothing to do with the RESET pin! */
> > +static int ov6650_reset(struct i2c_client *client)
> > +{
> > +	int ret;
> > +
> > +	dev_dbg(&client->dev, "reset\n");
> > +
> > +	ret = ov6650_reg_rmw(client, REG_COMA, COMA_RESET, 0);
> > +	if (ret)
> > +		dev_err(&client->dev,
> > +			"An error occured while entering soft reset!\n");
> > +
> > +	return ret;
> > +}

...
> > +/* Set status of additional camera capabilities */
> > +static int ov6650_s_ctrl(struct v4l2_subdev *sd, struct v4l2_control
> > *ctrl) +{
> > +	struct i2c_client *client = sd->priv;
> > +	struct ov6650 *priv = to_ov6650(client);
> > +	bool automatic;
> > +	int ret = 0;
> > +
> > +	switch (ctrl->id) {
> > +	case V4L2_CID_AUTOGAIN:
> > +		if (ctrl->value) {
> > +			ret = ov6650_reg_write(client, REG_GAIN, DEF_GAIN);
> > +			if (ret)
> > +				break;
> > +			priv->gain = DEF_GAIN;
> > +			ret = ov6650_reg_rmw(client, REG_COMB, COMB_AGC, 0);
> > +		} else {
> > +			ret = ov6650_reg_rmw(client, REG_COMB, 0, COMB_AGC);
> > +		}
> > +		if (ret)
> > +			break;
> > +		priv->agc = ctrl->value;
> > +		break;
> > +	case V4L2_CID_GAIN:
> > +		ret = ov6650_reg_write(client, REG_GAIN, ctrl->value);
> > +		if (ret)
> > +			break;
> > +		priv->gain = ctrl->value;
> > +		automatic = (priv->gain == DEF_GAIN);
> > +		if (automatic)
> > +			ret = ov6650_reg_rmw(client, REG_COMB, COMB_AGC, 0);
> > +		else
> > +			ret = ov6650_reg_rmw(client, REG_COMB, 0, COMB_AGC);
> > +		if (ret)
> > +			break;
> > +		priv->agc = automatic;
>
> I wouldn't touch autogain here. You have V4L2_CID_AUTOGAIN for that.
> Setting gain to a value, that happens to be equal default, doesn't have to
> turn autogain on, does it?

Right. The reason for doing it like this was being able to test controls using 
limited mplayer capabilities. Now that I've learned how I can do this with 
v4l2-dbg, I'll revert to a more common algorithm, for this one and all 
similiar cases below.

> > +		break;
> > +	case V4L2_CID_AUTO_WHITE_BALANCE:
> > +		if (ctrl->value) {
> > +			ret = ov6650_reg_write(client, REG_BLUE, DEF_BLUE);
> > +			if (ret)
> > +				break;
> > +			priv->blue = DEF_BLUE;
> > +			ret = ov6650_reg_write(client, REG_RED, DEF_RED);
> > +			if (ret)
> > +				break;
> > +			priv->red = DEF_RED;
> > +			ret = ov6650_reg_rmw(client, REG_COMB, COMB_AWB, 0);
> > +		} else {
> > +			ret = ov6650_reg_rmw(client, REG_COMB, 0, COMB_AWB);
> > +		}
> > +		if (ret)
> > +			break;
> > +		priv->awb = ctrl->value;
> > +		break;
> > +	case V4L2_CID_BLUE_BALANCE:
> > +		ret = ov6650_reg_write(client, REG_BLUE, ctrl->value);
> > +		if (ret)
> > +			break;
> > +		priv->blue = ctrl->value;
> > +		automatic = (priv->blue == DEF_BLUE &&
> > +				priv->red == DEF_RED);
> > +		if (automatic)
> > +			ret = ov6650_reg_rmw(client, REG_COMB, COMB_AWB, 0);
> > +		else
> > +			ret = ov6650_reg_rmw(client, REG_COMB, 0, COMB_AWB);
> > +		if (ret)
> > +			break;
> > +		priv->awb = automatic;
> > +		break;
> > +	case V4L2_CID_RED_BALANCE:
> > +		ret = ov6650_reg_write(client, REG_RED, ctrl->value);
> > +		if (ret)
> > +			break;
> > +		priv->red = ctrl->value;
> > +		automatic = (priv->blue == DEF_BLUE &&
> > +				priv->red == DEF_RED);
> > +		if (automatic)
> > +			ret = ov6650_reg_rmw(client, REG_COMB, COMB_AWB, 0);
> > +		else
> > +			ret = ov6650_reg_rmw(client, REG_COMB, 0, COMB_AWB);
> > +		if (ret)
> > +			break;
> > +		priv->awb = automatic;
>
> Same here, I wouldn't touch AWB in the above two controls. You have
> V4L2_CID_AUTO_WHITE_BALANCE for that.

ditto

> > +		break;
> > +	case V4L2_CID_SATURATION:
> > +		ret = ov6650_reg_rmw(client, REG_SAT, SET_SAT(ctrl->value),
> > +				SET_SAT(SAT_MASK));
>
> With the proposed change it would look like
>
> +		ret = ov6650_reg_rmw(client, REG_SAT, SET_SAT(ctrl->value),
> +				SAT_MASK);
>
> which I personally find a bit more pleasant to the eyes;)

Sure.

> > +		if (ret)
> > +			break;
> > +		priv->saturation = ctrl->value;
> > +		break;
> > +	case V4L2_CID_HUE_AUTO:
> > +		if (ctrl->value) {
> > +			ret = ov6650_reg_rmw(client, REG_HUE,
> > +					SET_HUE(DEF_HUE), SET_HUE(HUE_MASK));
> > +			if (ret)
> > +				break;
> > +			priv->hue = DEF_HUE;
> > +		} else {
> > +			ret = ov6650_reg_rmw(client, REG_HUE, HUE_EN, 0);
> > +		}
> > +		if (ret)
> > +			break;
> > +		priv->hue_auto = ctrl->value;
>
> Hm, sorry, don't understand. If the user sets auto-hue to ON, you set the
> hue enable bit and hue value to default. 

No, I reset the hue enable bit here, which I understand is used for applying a 
non-default hue value if set rather than enabling auto hue. Maybe my 
understanding of this bit function is wrong.

> If the user sets auto-hue to OFF, 
> you just set the hue enable bit on and don't change the value. Does ov6650
> actually support auto-hue?

All I was able to find out was the HUE register bits described like this:

Bit[7:6]: Reserved
Bit[5]: Hue Enable
Bit[4:0]: Hue setting

and the register default value: 0x10.

What do you think the bit[5] meaning is?

> > +		break;
> > +	case V4L2_CID_HUE:
> > +		ret = ov6650_reg_rmw(client, REG_HUE, SET_HUE(ctrl->value),
> > +				SET_HUE(HUE_MASK));
> > +		if (ret)
> > +			break;
> > +		priv->hue = ctrl->value;
> > +		priv->hue_auto = (priv->hue == DEF_HUE);
>
> Here it seems like in order to adjust hue you always have to set the
> enable bit. Again, I wouldn't touch hue_auto here - default and auto are
> different things.

Yes, one more mplayer testing related case that requires updating to a more 
common algorithm.

> > +		break;
> > +	case V4L2_CID_BRIGHTNESS:
> > +		ret = ov6650_reg_write(client, REG_BRT, ctrl->value);
> > +		if (ret)
> > +			break;
> > +		priv->brightness = ctrl->value;
> > +		break;
> > +	case V4L2_CID_EXPOSURE_AUTO:
> > +		switch (ctrl->value) {
> > +		case V4L2_EXPOSURE_AUTO:
> > +			ret = ov6650_reg_write(client, REG_AECH, DEF_AECH);
>
> Is this a requirement for auto-exposure, that you have to set the (analog
> manual) exposure to the default value?

Again, probably it's not.

> > +			if (ret)
> > +				break;
> > +			priv->exposure = DEF_AECH;
> > +			ret = ov6650_reg_rmw(client, REG_COMB, COMB_AEC, 0);
> > +			break;
> > +		default:
> > +			ret = ov6650_reg_rmw(client, REG_COMB, 0, COMB_AEC);
> > +			break;
> > +		}
> > +		if (ret)
> > +			break;
> > +		priv->aec = ctrl->value;
> > +		break;
> > +	case V4L2_CID_EXPOSURE:
> > +		ret = ov6650_reg_write(client, REG_AECH, ctrl->value);
> > +		if (ret)
> > +			break;
> > +		priv->exposure = ctrl->value;
> > +		automatic = (priv->exposure == DEF_AECH);
> > +		if (automatic)
> > +			ret = ov6650_reg_rmw(client, REG_COMB, COMB_AEC, 0);
> > +		else
> > +			ret = ov6650_reg_rmw(client, REG_COMB, 0, COMB_AEC);
> > +		if (ret)
> > +			break;
> > +		priv->aec = automatic ? V4L2_EXPOSURE_AUTO :
> > +				V4L2_EXPOSURE_MANUAL;
>
> Again - don't see why you need to touch the auto setting here.

Won't do this any longer.

> > +		break;
> > +	case V4L2_CID_GAMMA:
> > +		ret = ov6650_reg_write(client, REG_GAM1, ctrl->value);
> > +		if (ret)
> > +			break;
> > +		priv->gamma = ctrl->value;
> > +		break;
> > +	case V4L2_CID_VFLIP:
> > +		if (ctrl->value)
> > +			ret = ov6650_reg_rmw(client, REG_COMB,
> > +							COMB_FLIP_V, 0);
> > +		else
> > +			ret = ov6650_reg_rmw(client, REG_COMB,
> > +							0, COMB_FLIP_V);
> > +		if (ret)
> > +			break;
> > +		priv->vflip = ctrl->value;
> > +		break;
> > +	case V4L2_CID_HFLIP:
> > +		if (ctrl->value)
> > +			ret = ov6650_reg_rmw(client, REG_COMB,
> > +							COMB_FLIP_H, 0);
> > +		else
> > +			ret = ov6650_reg_rmw(client, REG_COMB,
> > +							0, COMB_FLIP_H);
> > +		if (ret)
> > +			break;
> > +		priv->hflip = ctrl->value;
> > +		break;
> > +	}
> > +
> > +	return ret;
> > +}

...
> > +/* select nearest higher resolution for capture */
> > +static void ov6650_res_roundup(u32 *width, u32 *height)
> > +{
> > +	int i;
> > +	enum { QCIF, CIF };
> > +	int res_x[] = { 176, 352 };
> > +	int res_y[] = { 144, 288 };
> > +
> > +	for (i = 0; i < ARRAY_SIZE(res_x); i++) {
> > +		if (res_x[i] >= *width && res_y[i] >= *height) {
> > +			*width = res_x[i];
> > +			*height = res_y[i];
> > +			return;
> > +		}
> > +	}
> > +
> > +	*width = res_x[CIF];
> > +	*height = res_y[CIF];
> > +}
>
> This can be replaced by a version of
>
> http://www.spinics.net/lists/linux-media/msg21893.html
>
> when it is fixed and accepted;) I'll try to send an updated version of
> that patch tomorrow.

Fine, I'll use this instead of my dirty workarounds.

> > +
> > +/* program default register values */
> > +static int ov6650_prog_dflt(struct i2c_client *client)
> > +{
> > +	int i, ret;
> > +
> > +	dev_dbg(&client->dev, "reinitializing\n");
> > +
> > +	for (i = 0; i < ARRAY_SIZE(ov6650_regs_dflt); i++) {
> > +		ret = ov6650_reg_write(client, ov6650_regs_dflt[i].reg,
> > +						ov6650_regs_dflt[i].val);
> > +		if (ret)
> > +			return ret;
> > +	}
>
> Hm, please, don't. I generally don't like such register - value array
> magic for a number of reasons, and in your case it's just one (!) register
> write operation - please, remove this array and just write the register
> explicitly. 

OK (with a reservation that I can probably end up with more than just one, 
non-default settings written explicitly).

> You also don't need DEF_COMA - writing an explicit "0" and 
> adding a comment - "clear all flags, including reset" would be perfect!

No problem, but to be honest, I didn't intend to clear any flags here except 
the reset flag, just reverting back to the register default reset value. Since 
an overall result will be the same, I can accept your way.

> > +
> > +	return 0;
> > +}
> > +
> > +/* set the format we will capture in */
> > +static int ov6650_s_fmt(struct v4l2_subdev *sd,
> > +			struct v4l2_mbus_framefmt *mf)
> > +{
> > +	struct i2c_client *client = sd->priv;
> > +	struct soc_camera_device *icd	= client->dev.platform_data;
> > +	struct soc_camera_sense *sense = icd->sense;
> > +	struct ov6650 *priv = to_ov6650(client);
> > +	enum v4l2_colorspace cspace;
> > +	enum v4l2_mbus_pixelcode code = mf->code;
> > +	unsigned long pclk;
> > +	u8 coma_set = 0, coma_mask = 0, coml_set = 0, coml_mask = 0, clkrc;
> > +	int ret;
> > +
> > +	/* select color matrix configuration for given color encoding */
> > +	switch (code) {
> > +	case V4L2_MBUS_FMT_GREY8_1X8:
> > +		dev_dbg(&client->dev, "pixel format GREY8_1X8\n");
> > +		coma_set |= COMA_BW;
> > +		coma_mask |= COMA_RGB | COMA_WORD_SWAP | COMA_BYTE_SWAP;
> > +		coml_mask |= COML_ONE_CHANNEL;
> > +		cspace = V4L2_COLORSPACE_JPEG;
> > +		priv->pclk_max = 4000000;
> > +		break;
> > +	case V4L2_MBUS_FMT_YUYV8_2X8_LE:
> > +		dev_dbg(&client->dev, "pixel format YUYV8_2X8_LE\n");
> > +		coma_set |= COMA_WORD_SWAP;
> > +		coma_mask |= COMA_RGB | COMA_BW | COMA_BYTE_SWAP;
> > +		goto yuv;
>
> Well, this doesn't look critical to me, i.e., eventually I would accept
> this, but, as you know, goto's in the kernel are (almost) only used for
> failure cases, besides, what makes this use even less pretty, this is a
> goto into a switch statement... I would set a "yuv = 1" variable instead
> of goto's, and use a "if (yuv) after the switch.

OK, I'll rearrange this piece of code like you suggest to avoid a goto.

> > +	case V4L2_MBUS_FMT_YVYU8_2X8_LE:
> > +		dev_dbg(&client->dev, "pixel format YVYU8_2X8_LE (untested)\n");
> > +		coma_mask |= COMA_RGB | COMA_BW | COMA_WORD_SWAP |
> > +				COMA_BYTE_SWAP;
> > +		goto yuv;
> > +	case V4L2_MBUS_FMT_YUYV8_2X8_BE:
> > +		dev_dbg(&client->dev, "pixel format YUYV8_2X8_BE\n");
> > +		if (mf->width == W_CIF) {
> > +			coma_set |= COMA_BYTE_SWAP | COMA_WORD_SWAP;
> > +			coma_mask |= COMA_RGB | COMA_BW;
> > +		} else {
> > +			coma_set |= COMA_BYTE_SWAP;
> > +			coma_mask |= COMA_RGB | COMA_BW | COMA_WORD_SWAP;
> > +		}
> > +		goto yuv;
> > +	case V4L2_MBUS_FMT_YVYU8_2X8_BE:
> > +		dev_dbg(&client->dev, "pixel format YVYU8_2X8_BE (untested)\n");
> > +		if (mf->width == W_CIF) {
> > +			coma_set |= COMA_BYTE_SWAP;
> > +			coma_mask |= COMA_RGB | COMA_BW | COMA_WORD_SWAP;
> > +		} else {
> > +			coma_set |= COMA_BYTE_SWAP | COMA_WORD_SWAP;
> > +			coma_mask |= COMA_RGB | COMA_BW;
> > +		}
> > +yuv:
> > +		coml_set |= COML_ONE_CHANNEL;
> > +		cspace = V4L2_COLORSPACE_JPEG;
> > +		priv->pclk_max = 8000000;
> > +		break;
> > +	case V4L2_MBUS_FMT_SBGGR8_1X8:
> > +		dev_dbg(&client->dev, "pixel format SBGGR8_1X8 (untested)\n");
> > +		coma_set |= COMA_RAW_RGB | COMA_RGB;
> > +		coma_mask |= COMA_BW | COMA_BYTE_SWAP | COMA_WORD_SWAP;
> > +		coml_mask |= COML_ONE_CHANNEL;
> > +		cspace = V4L2_COLORSPACE_SRGB;
> > +		priv->pclk_max = 4000000;
> > +		break;
> > +	default:
> > +		dev_err(&client->dev, "Pixel format not handled : %x\n", code);
> > +		return -EINVAL;
> > +	}
> > +
> > +	/* select register configuration for given resolution */
> > +	ov6650_res_roundup(&mf->width, &mf->height);
> > +
> > +	switch (mf->width) {
> > +	case W_QCIF:
> > +		dev_dbg(&client->dev, "resolution QCIF\n");
> > +		priv->qcif = 1;
> > +		coma_set |= COMA_QCIF;
> > +		priv->pclk_max /= 2;
> > +		break;
> > +	case W_CIF:
> > +		dev_dbg(&client->dev, "resolution CIF\n");
> > +		priv->qcif = 0;
> > +		coma_mask |= COMA_QCIF;
> > +		break;
> > +	default:
> > +		dev_err(&client->dev, "unspported resolution!\n");
> > +		return -EINVAL;
> > +	}
> > +
> > +	if (priv->timeperframe.numerator && priv->timeperframe.denominator)
> > +		pclk = priv->pclk_max * priv->timeperframe.denominator /
> > +				(FRAME_RATE_MAX * priv->timeperframe.numerator);
> > +	else
> > +		pclk = priv->pclk_max;
> > +
> > +	if (sense) {
> > +		if (sense->master_clock == 8000000) {
> > +			dev_dbg(&client->dev, "8MHz input clock\n");
> > +			clkrc = CLKRC_6MHz;
> > +		} else if (sense->master_clock == 12000000) {
> > +			dev_dbg(&client->dev, "12MHz input clock\n");
> > +			clkrc = CLKRC_12MHz;
> > +		} else if (sense->master_clock == 16000000) {
> > +			dev_dbg(&client->dev, "16MHz input clock\n");
> > +			clkrc = CLKRC_16MHz;
> > +		} else if (sense->master_clock == 24000000) {
> > +			dev_dbg(&client->dev, "24MHz input clock\n");
> > +			clkrc = CLKRC_24MHz;
> > +		} else {
> > +			dev_err(&client->dev,
> > +				"unspported input clock, check platform data"
> > +				"\n");
> > +			return -EINVAL;
> > +		}
> > +		priv->pclk_limit = sense->pixel_clock_max;
> > +		if (priv->pclk_limit &&
> > +				(priv->pclk_limit < pclk))
>
> This can go on one line.

It will.

> > +			pclk = priv->pclk_limit;
> > +	} else {
> > +		priv->pclk_limit = 0;
> > +		clkrc = 0xc0;
> > +		dev_dbg(&client->dev, "using default 24MHz input clock\n");
> > +	}
> > +
> > +	clkrc |= (priv->pclk_max - 1) / pclk;
> > +	pclk = priv->pclk_max / GET_CLKRC_DIV(clkrc);
>
> This would look better as
>
> 	clkrc_div = (priv->pclk_max - 1) / pclk;
> 	clkrc |= clkrc_div;
> 	pclk = priv->pclk_max / clkrc_div;

OK.

> > +	dev_dbg(&client->dev, "pixel clock divider: %ld.%ld\n",
> > +			sense->master_clock / pclk,
> > +			10 * sense->master_clock % pclk / pclk);
> > +
> > +	ov6650_reset(client);
> > +
> > +	ret = ov6650_prog_dflt(client);
> > +	if (ret)
> > +		return ret;
> > +
> > +
>
> Superfluous empty line;)

Mhm.

> > +	ret = ov6650_reg_rmw(client, REG_COMA, coma_set, coma_mask);
> > +	if (!ret)
> > +		ret = ov6650_reg_write(client, REG_CLKRC, clkrc);
> > +	if (!ret)
> > +		ret = ov6650_reg_rmw(client, REG_COML, coml_set, coml_mask);
> > +
> > +	if (!ret) {
> > +		mf->code	= code;
> > +		mf->colorspace	= cspace;
> > +	}
> > +
> > +	return ret;
> > +}

...
> > +static int ov6650_cropcap(struct v4l2_subdev *sd, struct v4l2_cropcap
> > *a) +{
> > +	struct i2c_client *client = sd->priv;
> > +	struct ov6650 *priv = to_ov6650(client);
> > +	int shift = !priv->qcif;
> > +
> > +	if (a->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
> > +		return -EINVAL;
> > +
> > +	/* Crop limits depend on selected frame format (CIF/QCIF) */
> > +	a->bounds.left			= DEF_HSTRT << shift;
> > +	a->bounds.top			= DEF_VSTRT << shift;
> > +	a->bounds.width			= W_QCIF << shift;
> > +	a->bounds.height		= H_QCIF << shift;
> > +	/* REVISIT: should defrect provide actual or default geometry? */
>
> default

Thanks for clarification.

> > +	a->defrect			= a->bounds;
> > +	a->pixelaspect.numerator	= 1;
> > +	a->pixelaspect.denominator	= 1;
> > +
> > +	return 0;
> > +}

...
> > +static int ov6650_s_crop(struct v4l2_subdev *sd, struct v4l2_crop *a)
> > +{
> > +	struct i2c_client *client = sd->priv;
> > +	struct ov6650 *priv = to_ov6650(client);
> > +	struct v4l2_rect *rect = &a->c;
> > +	int shift = !priv->qcif;
> > +	u8 hstrt, vstrt, hstop, vstop;
> > +	int ret;
> > +
> > +	if (a->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
> > +		return -EINVAL;
> > +
> > +	hstrt = rect->left >> shift;
> > +	vstrt = rect->top >> shift;
> > +	hstop = hstrt + (rect->width >> shift);
> > +	vstop = vstrt + (rect->height >> shift);
> > +
> > +	if ((hstop > DEF_HSTOP) || (vstop > DEF_VSTOP)) {
> > +		dev_err(&client->dev, "Invalid window geometry!\n");
> > +		return -EINVAL;
> > +	}
> > +
> > +	ret = ov6650_reg_write(client, REG_HSTRT, hstrt);
> > +	if (!ret)
> > +		ret = ov6650_reg_write(client, REG_HSTOP, hstop);
> > +	if (!ret)
> > +		ret = ov6650_reg_write(client, REG_VSTRT, vstrt);
> > +	if (!ret)
> > +		ret = ov6650_reg_write(client, REG_VSTOP, vstop);
>
> Are cropping and scaling on this camera absolutely independent? I.e., you
> can set any output format (CIF or QCIF) and it will just scale whatever
> rectangle has been configured? And the other way round - you set arbitrary
> cropping and output format stays the same?

I believe it works like I have put it here, but will try to recheck to make 
sure. Simply using v4l2-debug for this seems insufficient, since changing a 
frame format on the fly will get DMA out of sync immediately. What tool or 
utility could you advise for testing?

> > +
> > +	return ret;
> > +}

...
> > +static struct soc_camera_ops ov6650_ops = {
> > +	.set_bus_param		= ov6650_set_bus_param,
> > +	.query_bus_param	= ov6650_query_bus_param,
> > +	.controls		= ov6650_controls,
> > +	.num_controls		= ARRAY_SIZE(ov6650_controls),
> > +};
> > +
> > +static struct v4l2_subdev_core_ops ov6650_core_ops = {
> > +	.g_ctrl			= ov6650_g_ctrl,
> > +	.s_ctrl			= ov6650_s_ctrl,
> > +	.g_chip_ident		= ov6650_g_chip_ident,
> > +#ifdef CONFIG_VIDEO_ADV_DEBUG
> > +	.g_register		= ov6650_get_register,
> > +	.s_register		= ov6650_set_register,
> > +#endif
> > +
>
> Superfluous empty line

Will remove.

> > +};
> > +
> > +static struct v4l2_subdev_video_ops ov6650_video_ops = {
> > +	.s_stream	= ov6650_s_stream,
> > +	.s_mbus_fmt	= ov6650_s_fmt,
> > +	.try_mbus_fmt	= ov6650_try_fmt,
>
> Please, implement.g_mbus_fmt.

OK (in addition to what I've already implemented, I guess).

> > +	.enum_mbus_fmt	= ov6650_enum_fmt,
> > +	.cropcap	= ov6650_cropcap,
> > +	.g_crop		= ov6650_g_crop,
> > +	.s_crop		= ov6650_s_crop,
> > +	.g_parm		= ov6650_g_parm,
> > +	.s_parm		= ov6650_s_parm,
> > +
>
> Superfluous empty line

Mhm.

> > +};
> > +
> > +static struct v4l2_subdev_ops ov6650_subdev_ops = {
> > +	.core	= &ov6650_core_ops,
> > +	.video	= &ov6650_video_ops,
> > +};
> > +
> > +/*
> > + * i2c_driver function
> > + */
> > +static int ov6650_probe(struct i2c_client *client,
> > +			const struct i2c_device_id *did)
> > +{
> > +	struct ov6650 *priv;
> > +	struct soc_camera_device *icd	= client->dev.platform_data;
>
> Nothing to align here, a space before "=" would suffice;)

OK.

> > +	struct soc_camera_link *icl;
> > +	int ret;
> > +
> > +	if (!icd) {
> > +		dev_err(&client->dev, "Missing soc-camera data!\n");
> > +		return -EINVAL;
> > +	}
> > +
> > +	icl = to_soc_camera_link(icd);
> > +	if (!icl) {
> > +		dev_err(&client->dev, "Missing platform_data for driver\n");
> > +		return -EINVAL;
> > +	}
> > +
> > +	priv = kzalloc(sizeof(struct ov6650), GFP_KERNEL);
> > +	if (!priv) {
> > +		dev_err(&client->dev,
> > +			"Failed to allocate memory for private data!\n");
> > +		return -ENOMEM;
> > +	}
> > +
> > +	v4l2_i2c_subdev_init(&priv->subdev, client, &ov6650_subdev_ops);
> > +
> > +	icd->ops	= &ov6650_ops;
>
> A matter of taste, eventually, but I'd use a space.

OK.

> > +
> > +	ret = ov6650_video_probe(icd, client);
> > +
> > +	if (ret) {
> > +		icd->ops = NULL;
> > +		i2c_set_clientdata(client, NULL);
> > +		kfree(priv);
> > +	}
> > +
> > +	return ret;
> > +}

Thanks,
Janusz

Re: [RFC] [PATCH 3/6] SoC Camera: add driver for OV6650 sensor

[Guennadi Liakhovetski]

On Sun, 22 Aug 2010, Janusz Krzysztofik wrote:

> Hi Guennadi,
> Thanks for your review time.
> 
> Sunday 22 August 2010 18:40:13 Guennadi Liakhovetski wrote:
> > On Sun, 18 Jul 2010, Janusz Krzysztofik wrote:
> > > This patch provides a V4L2 SoC Camera driver for OV6650 camera sensor,
> > > found on OMAP1 SoC based Amstrad Delta videophone.
> >
> > Have you also had a look at drivers/media/video/gspca/sonixb.c - in also
> > supports ov6650 among other sensors.
> 
> Yes, I have, but given up for now since:
> 1. the gspca seems using the sensor in "Bayer 8 BGGR" mode only, which I was 
>    not even able to select using mplayer to test my drivers with,
> 2. not all settings used there are clear for me, so I've decided to revisit 
>    them later, when I first get a stable, even if not perfect, working driver 
>    version accepted, instead of following them blindly.

But good that you've looked at it.

> > > +	unsigned char data[2] = { reg, val };
> > > +	struct i2c_msg msg = {
> > > +		.addr	= client->addr,
> > > +		.flags	= 0,
> > > +		.len	= 2,
> > > +		.buf	= data,
> > > +	};
> > > +
> > > +	ret = i2c_transfer(client->adapter, &msg, 1);
> > > +	if (ret < 0) {
> > > +		dev_err(&client->dev, "Failed writing register 0x%02x!\n", reg);
> > > +		return ret;
> > > +	}
> > > +	msleep(1);
> >
> > Hm, interesting... Is this really needed?
> 
> If you mean msleep(1) - yes, the sensor didn't work correctly for me without 
> that msleep().

Yes, I meant msleep(1).

> I you mean reading the register back - I've not tried without, will do.

Ok.

> > > +	case V4L2_CID_HUE_AUTO:
> > > +		if (ctrl->value) {
> > > +			ret = ov6650_reg_rmw(client, REG_HUE,
> > > +					SET_HUE(DEF_HUE), SET_HUE(HUE_MASK));
> > > +			if (ret)
> > > +				break;
> > > +			priv->hue = DEF_HUE;
> > > +		} else {
> > > +			ret = ov6650_reg_rmw(client, REG_HUE, HUE_EN, 0);
> > > +		}
> > > +		if (ret)
> > > +			break;
> > > +		priv->hue_auto = ctrl->value;
> >
> > Hm, sorry, don't understand. If the user sets auto-hue to ON, you set the
> > hue enable bit and hue value to default. 
> 
> No, I reset the hue enable bit here, which I understand is used for applying a 
> non-default hue value if set rather than enabling auto hue. Maybe my 
> understanding of this bit function is wrong.
> 
> > If the user sets auto-hue to OFF, 
> > you just set the hue enable bit on and don't change the value. Does ov6650
> > actually support auto-hue?
> 
> All I was able to find out was the HUE register bits described like this:
> 
> Bit[7:6]: Reserved
> Bit[5]: Hue Enable
> Bit[4:0]: Hue setting
> 
> and the register default value: 0x10.
> 
> What do you think the bit[5] meaning is?

Well, from how I interpret, what you say, I think, there is no auto-hue 
implemented by this sensor, at least, not by this register. Maybe drop 
auto-hue support completely? It seems to me just a manual hue value can be 
set.

> > > +/* select nearest higher resolution for capture */
> > > +static void ov6650_res_roundup(u32 *width, u32 *height)
> > > +{
> > > +	int i;
> > > +	enum { QCIF, CIF };
> > > +	int res_x[] = { 176, 352 };
> > > +	int res_y[] = { 144, 288 };
> > > +
> > > +	for (i = 0; i < ARRAY_SIZE(res_x); i++) {
> > > +		if (res_x[i] >= *width && res_y[i] >= *height) {
> > > +			*width = res_x[i];
> > > +			*height = res_y[i];
> > > +			return;
> > > +		}
> > > +	}
> > > +
> > > +	*width = res_x[CIF];
> > > +	*height = res_y[CIF];
> > > +}
> >
> > This can be replaced by a version of
> >
> > http://www.spinics.net/lists/linux-media/msg21893.html
> >
> > when it is fixed and accepted;) I'll try to send an updated version of
> > that patch tomorrow.
> 
> Fine, I'll use this instead of my dirty workarounds.

/me has to update that patch... Will try to do that asap.

> > > +
> > > +/* program default register values */
> > > +static int ov6650_prog_dflt(struct i2c_client *client)
> > > +{
> > > +	int i, ret;
> > > +
> > > +	dev_dbg(&client->dev, "reinitializing\n");
> > > +
> > > +	for (i = 0; i < ARRAY_SIZE(ov6650_regs_dflt); i++) {
> > > +		ret = ov6650_reg_write(client, ov6650_regs_dflt[i].reg,
> > > +						ov6650_regs_dflt[i].val);
> > > +		if (ret)
> > > +			return ret;
> > > +	}
> >
> > Hm, please, don't. I generally don't like such register - value array
> > magic for a number of reasons, and in your case it's just one (!) register
> > write operation - please, remove this array and just write the register
> > explicitly. 
> 
> OK (with a reservation that I can probably end up with more than just one, 
> non-default settings written explicitly).

Thas's ok. I find a sequence of explicit register writes nicer, e.g., 
because then you can insert comments / delays / meaningful debugging / 
other branching between them. Pushing an array of register values to the 
hardware looks like "no idea what this stuff is good for, I just copied 
this from vendor's example / sniffed from the hardware..."

> > > +	ret = ov6650_reg_write(client, REG_HSTRT, hstrt);
> > > +	if (!ret)
> > > +		ret = ov6650_reg_write(client, REG_HSTOP, hstop);
> > > +	if (!ret)
> > > +		ret = ov6650_reg_write(client, REG_VSTRT, vstrt);
> > > +	if (!ret)
> > > +		ret = ov6650_reg_write(client, REG_VSTOP, vstop);
> >
> > Are cropping and scaling on this camera absolutely independent? I.e., you
> > can set any output format (CIF or QCIF) and it will just scale whatever
> > rectangle has been configured? And the other way round - you set arbitrary
> > cropping and output format stays the same?
> 
> I believe it works like I have put it here, but will try to recheck to make 
> sure. Simply using v4l2-debug for this seems insufficient, since changing a 
> frame format on the fly will get DMA out of sync immediately. What tool or 
> utility could you advise for testing?

firstly, soc-camera is quite restrictive about s_crop ATM: it disallows 
changes to the cropping sizes (only position can be changed). Whereby, now 
that I think about it again, perhaps this wasn't a very good idea: 
effectively this kills live zooming. Maybe we can lift that restriction 
again. In any case, I don't know any existing programs, that can stream 
video and simultaneously allow the user to issue crop and scale commands. 
I just hacked mplayer and gstreamer for that. Or, to test changing left 
and top offsets, I had mplayer running and issued crops and scales from 
another window with a command-line tool like v4l2-dbg.

> > > +static struct v4l2_subdev_video_ops ov6650_video_ops = {
> > > +	.s_stream	= ov6650_s_stream,
> > > +	.s_mbus_fmt	= ov6650_s_fmt,
> > > +	.try_mbus_fmt	= ov6650_try_fmt,
> >
> > Please, implement.g_mbus_fmt.
> 
> OK (in addition to what I've already implemented, I guess).

Of course

Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/

Re: [RFC] [PATCH 3/6] SoC Camera: add driver for OV6650 sensor

[Marek Vasut]

Dne Ne 22. srpna 2010 22:30:10 Guennadi Liakhovetski napsal(a):
> On Sun, 22 Aug 2010, Janusz Krzysztofik wrote:
> > Hi Guennadi,
> > Thanks for your review time.
> > 
> > Sunday 22 August 2010 18:40:13 Guennadi Liakhovetski wrote:
> > > On Sun, 18 Jul 2010, Janusz Krzysztofik wrote:
> > > > This patch provides a V4L2 SoC Camera driver for OV6650 camera
> > > > sensor, found on OMAP1 SoC based Amstrad Delta videophone.
> > > 
> > > Have you also had a look at drivers/media/video/gspca/sonixb.c - in
> > > also supports ov6650 among other sensors.
> > 
> > Yes, I have, but given up for now since:
> > 1. the gspca seems using the sensor in "Bayer 8 BGGR" mode only, which I
> > was
> > 
> >    not even able to select using mplayer to test my drivers with,
> > 
> > 2. not all settings used there are clear for me, so I've decided to
> > revisit
> > 
> >    them later, when I first get a stable, even if not perfect, working
> >    driver version accepted, instead of following them blindly.
> 
> But good that you've looked at it.
> 
> > > > +	unsigned char data[2] = { reg, val };
> > > > +	struct i2c_msg msg = {
> > > > +		.addr	= client->addr,
> > > > +		.flags	= 0,
> > > > +		.len	= 2,
> > > > +		.buf	= data,
> > > > +	};
> > > > +
> > > > +	ret = i2c_transfer(client->adapter, &msg, 1);
> > > > +	if (ret < 0) {
> > > > +		dev_err(&client->dev, "Failed writing register 0x%02x!
\n", reg);
> > > > +		return ret;
> > > > +	}
> > > > +	msleep(1);
> > > 
> > > Hm, interesting... Is this really needed?
> > 
> > If you mean msleep(1) - yes, the sensor didn't work correctly for me
> > without that msleep().
> 
> Yes, I meant msleep(1).

Doesn't surprise me at all actually. Check how this is done on ov9640 and also 
NOTE I had to use gpio-spi module instead of pxa-spi to get the communication 
running at all ... might be your case.

Cheers
> 
> > I you mean reading the register back - I've not tried without, will do.
> 
> Ok.
> 
> > > > +	case V4L2_CID_HUE_AUTO:
> > > > +		if (ctrl->value) {
> > > > +			ret = ov6650_reg_rmw(client, REG_HUE,
> > > > +					SET_HUE(DEF_HUE), 
SET_HUE(HUE_MASK));
> > > > +			if (ret)
> > > > +				break;
> > > > +			priv->hue = DEF_HUE;
> > > > +		} else {
> > > > +			ret = ov6650_reg_rmw(client, REG_HUE, HUE_EN, 
0);
> > > > +		}
> > > > +		if (ret)
> > > > +			break;
> > > > +		priv->hue_auto = ctrl->value;
> > > 
> > > Hm, sorry, don't understand. If the user sets auto-hue to ON, you set
> > > the hue enable bit and hue value to default.
> > 
> > No, I reset the hue enable bit here, which I understand is used for
> > applying a non-default hue value if set rather than enabling auto hue.
> > Maybe my understanding of this bit function is wrong.
> > 
> > > If the user sets auto-hue to OFF,
> > > you just set the hue enable bit on and don't change the value. Does
> > > ov6650 actually support auto-hue?
> > 
> > All I was able to find out was the HUE register bits described like this:
> > 
> > Bit[7:6]: Reserved
> > Bit[5]: Hue Enable
> > Bit[4:0]: Hue setting
> > 
> > and the register default value: 0x10.
> > 
> > What do you think the bit[5] meaning is?
> 
> Well, from how I interpret, what you say, I think, there is no auto-hue
> implemented by this sensor, at least, not by this register. Maybe drop
> auto-hue support completely? It seems to me just a manual hue value can be
> set.
> 
> > > > +/* select nearest higher resolution for capture */
> > > > +static void ov6650_res_roundup(u32 *width, u32 *height)
> > > > +{
> > > > +	int i;
> > > > +	enum { QCIF, CIF };
> > > > +	int res_x[] = { 176, 352 };
> > > > +	int res_y[] = { 144, 288 };
> > > > +
> > > > +	for (i = 0; i < ARRAY_SIZE(res_x); i++) {
> > > > +		if (res_x[i] >= *width && res_y[i] >= *height) {
> > > > +			*width = res_x[i];
> > > > +			*height = res_y[i];
> > > > +			return;
> > > > +		}
> > > > +	}
> > > > +
> > > > +	*width = res_x[CIF];
> > > > +	*height = res_y[CIF];
> > > > +}
> > > 
> > > This can be replaced by a version of
> > > 
> > > http://www.spinics.net/lists/linux-media/msg21893.html
> > > 
> > > when it is fixed and accepted;) I'll try to send an updated version of
> > > that patch tomorrow.
> > 
> > Fine, I'll use this instead of my dirty workarounds.
> 
> /me has to update that patch... Will try to do that asap.
> 
> > > > +
> > > > +/* program default register values */
> > > > +static int ov6650_prog_dflt(struct i2c_client *client)
> > > > +{
> > > > +	int i, ret;
> > > > +
> > > > +	dev_dbg(&client->dev, "reinitializing\n");
> > > > +
> > > > +	for (i = 0; i < ARRAY_SIZE(ov6650_regs_dflt); i++) {
> > > > +		ret = ov6650_reg_write(client, ov6650_regs_dflt[i].reg,
> > > > +						
ov6650_regs_dflt[i].val);
> > > > +		if (ret)
> > > > +			return ret;
> > > > +	}
> > > 
> > > Hm, please, don't. I generally don't like such register - value array
> > > magic for a number of reasons, and in your case it's just one (!)
> > > register write operation - please, remove this array and just write
> > > the register explicitly.
> > 
> > OK (with a reservation that I can probably end up with more than just
> > one, non-default settings written explicitly).
> 
> Thas's ok. I find a sequence of explicit register writes nicer, e.g.,
> because then you can insert comments / delays / meaningful debugging /
> other branching between them. Pushing an array of register values to the
> hardware looks like "no idea what this stuff is good for, I just copied
> this from vendor's example / sniffed from the hardware..."
> 
> > > > +	ret = ov6650_reg_write(client, REG_HSTRT, hstrt);
> > > > +	if (!ret)
> > > > +		ret = ov6650_reg_write(client, REG_HSTOP, hstop);
> > > > +	if (!ret)
> > > > +		ret = ov6650_reg_write(client, REG_VSTRT, vstrt);
> > > > +	if (!ret)
> > > > +		ret = ov6650_reg_write(client, REG_VSTOP, vstop);
> > > 
> > > Are cropping and scaling on this camera absolutely independent? I.e.,
> > > you can set any output format (CIF or QCIF) and it will just scale
> > > whatever rectangle has been configured? And the other way round - you
> > > set arbitrary cropping and output format stays the same?
> > 
> > I believe it works like I have put it here, but will try to recheck to
> > make sure. Simply using v4l2-debug for this seems insufficient, since
> > changing a frame format on the fly will get DMA out of sync immediately.
> > What tool or utility could you advise for testing?
> 
> firstly, soc-camera is quite restrictive about s_crop ATM: it disallows
> changes to the cropping sizes (only position can be changed). Whereby, now
> that I think about it again, perhaps this wasn't a very good idea:
> effectively this kills live zooming. Maybe we can lift that restriction
> again. In any case, I don't know any existing programs, that can stream
> video and simultaneously allow the user to issue crop and scale commands.
> I just hacked mplayer and gstreamer for that. Or, to test changing left
> and top offsets, I had mplayer running and issued crops and scales from
> another window with a command-line tool like v4l2-dbg.
> 
> > > > +static struct v4l2_subdev_video_ops ov6650_video_ops = {
> > > > +	.s_stream	= ov6650_s_stream,
> > > > +	.s_mbus_fmt	= ov6650_s_fmt,
> > > > +	.try_mbus_fmt	= ov6650_try_fmt,
> > > 
> > > Please, implement.g_mbus_fmt.
> > 
> > OK (in addition to what I've already implemented, I guess).
> 
> Of course
> 
> Thanks
> Guennadi
> ---
> Guennadi Liakhovetski, Ph.D.
> Freelance Open-Source Software Developer
> http://www.open-technology.de/
> --
> To unsubscribe from this list: send the line "unsubscribe linux-media" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

[RFC] [PATCH 4/6] SoC Camera: add support for g_parm / s_parm operations

[Janusz Krzysztofik]

This patch adds support for g_parm / s_parm operations to the SoC Camera 
framework. It is usefull for checking/setting camera frame rate.

Example usage can be found in the previous patch from this series, 
"SoC Camera: add driver for OV6650 sensor".

Created and tested against linux-2.6.35-rc3 on Amstrad Delta.

Signed-off-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
---
 drivers/media/video/soc_camera.c |   18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

--- linux-2.6.35-rc3.orig/drivers/media/video/soc_camera.c	2010-06-26 15:55:34.000000000 +0200
+++ linux-2.6.35-rc3/drivers/media/video/soc_camera.c	2010-06-27 00:04:10.000000000 +0200
@@ -1144,6 +1144,20 @@ static int default_s_crop(struct soc_cam
 	return v4l2_subdev_call(sd, video, s_crop, a);
 }
 
+static int default_g_parm(struct soc_camera_device *icd,
+			  struct v4l2_streamparm *parm)
+{
+	struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
+	return v4l2_subdev_call(sd, video, g_parm, parm);
+}
+
+static int default_s_parm(struct soc_camera_device *icd,
+			  struct v4l2_streamparm *parm)
+{
+	struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
+	return v4l2_subdev_call(sd, video, s_parm, parm);
+}
+
 static void soc_camera_device_init(struct device *dev, void *pdata)
 {
 	dev->platform_data	= pdata;
@@ -1175,6 +1189,10 @@ int soc_camera_host_register(struct soc_
 		ici->ops->get_crop = default_g_crop;
 	if (!ici->ops->cropcap)
 		ici->ops->cropcap = default_cropcap;
+	if (!ici->ops->set_parm)
+		ici->ops->set_parm = default_s_parm;
+	if (!ici->ops->get_parm)
+		ici->ops->get_parm = default_g_parm;
 
 	mutex_lock(&list_lock);
 	list_for_each_entry(ix, &hosts, list) {

[RFC] [PATCH 5/6] OMAP1: Amstrad Delta: add support for camera

[Janusz Krzysztofik]

This patch adds configuration data and initialization code required for camera 
support to the Amstrad Delta board.

Three devices are declared: SoC camera, OMAP1 camera interface and OV6650 
sensor.

Default 12MHz clock has been selected for driving the sensor. Pixel clock has 
been limited to get reasonable frame rates, not exceeding the board 
capabilities. Since both devices (interface and sensor) support both pixel 
clock polarities, decision on polarity selection has been left to drivers.
Interface GPIO line has been found not functional, thus not configured.

Created and tested against linux-2.6.35-rc3.

Works on top of previous patches from the series, at least 1/6, 2/6 and 3/6.

Signed-off-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
---
 arch/arm/mach-omap1/board-ams-delta.c |   45 ++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

--- linux-2.6.35-rc3.orig/arch/arm/mach-omap1/board-ams-delta.c	2010-06-26 15:54:47.000000000 +0200
+++ linux-2.6.35-rc3/arch/arm/mach-omap1/board-ams-delta.c	2010-07-18 02:21:23.000000000 +0200
@@ -19,6 +19,8 @@
 #include <linux/platform_device.h>
 #include <linux/serial_8250.h>
 
+#include <media/soc_camera.h>
+
 #include <asm/serial.h>
 #include <mach/hardware.h>
 #include <asm/mach-types.h>
@@ -32,6 +34,7 @@
 #include <plat/usb.h>
 #include <plat/board.h>
 #include <plat/common.h>
+#include <mach/camera.h>
 
 #include <mach/ams-delta-fiq.h>
 
@@ -213,10 +216,37 @@ static struct platform_device ams_delta_
 	.id	= -1
 };
 
+static struct i2c_board_info ams_delta_camera_board_info[] = {
+	{
+		I2C_BOARD_INFO("ov6650", 0x60),
+	},
+};
+
+static struct soc_camera_link __initdata ams_delta_iclink = {
+	.bus_id         = 0,	/* OMAP1 SoC camera bus */
+	.i2c_adapter_id = 1,
+	.board_info     = &ams_delta_camera_board_info[0],
+	.module_name    = "ov6650",
+};
+
+static struct platform_device ams_delta_camera_device = {
+	.name   = "soc-camera-pdrv",
+	.id     = 0,
+	.dev    = {
+		.platform_data = &ams_delta_iclink,
+	},
+};
+
+static struct omap1_cam_platform_data ams_delta_camera_platform_data = {
+	.camexclk_khz	= 12000,	/* default 12MHz clock, no extra DPLL */
+	.lclk_khz_max	= 1334,		/* results in 5fps CIF, 10fps QCIF */
+};
+
 static struct platform_device *ams_delta_devices[] __initdata = {
 	&ams_delta_kp_device,
 	&ams_delta_lcd_device,
 	&ams_delta_led_device,
+	&ams_delta_camera_device,
 };
 
 static void __init ams_delta_init(void)
@@ -225,6 +255,20 @@ static void __init ams_delta_init(void)
 	omap_cfg_reg(UART1_TX);
 	omap_cfg_reg(UART1_RTS);
 
+	/* parallel camera interface */
+	omap_cfg_reg(H19_1610_CAM_EXCLK);
+	omap_cfg_reg(J15_1610_CAM_LCLK);
+	omap_cfg_reg(L18_1610_CAM_VS);
+	omap_cfg_reg(L15_1610_CAM_HS);
+	omap_cfg_reg(L19_1610_CAM_D0);
+	omap_cfg_reg(K14_1610_CAM_D1);
+	omap_cfg_reg(K15_1610_CAM_D2);
+	omap_cfg_reg(K19_1610_CAM_D3);
+	omap_cfg_reg(K18_1610_CAM_D4);
+	omap_cfg_reg(J14_1610_CAM_D5);
+	omap_cfg_reg(J19_1610_CAM_D6);
+	omap_cfg_reg(J18_1610_CAM_D7);
+
 	iotable_init(ams_delta_io_desc, ARRAY_SIZE(ams_delta_io_desc));
 
 	omap_board_config = ams_delta_config;
@@ -236,6 +280,7 @@ static void __init ams_delta_init(void)
 	ams_delta_latch2_write(~0, 0);
 
 	omap_usb_init(&ams_delta_usb_config);
+	omap1_set_camera_info(&ams_delta_camera_platform_data);
 	platform_add_devices(ams_delta_devices, ARRAY_SIZE(ams_delta_devices));
 
 #ifdef CONFIG_AMS_DELTA_FIQ

[RFC] [PATCH 6/6] OMAP1: Amstrad Delta: add camera controlled LEDS trigger

[Janusz Krzysztofik]

This patch extends the Amstrad Delta camera support with LEDS trigger that can 
be used for automatic control of the on-board camera LED. The led turns on 
automatically on camera device open and turns off on camera device close.

If you find this solution usefull for other boards / machines / platforms 
as well, I can try to reimplement it at the SoC camera framework level, or 
OMAP1 camera interface level.

Created and tested against linux-2.6.35-rc3.

Works on top of patch 5/6, "OMAP1: Amstrad Delta: add support for on-board 
camera"

Signed-off-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
---
 arch/arm/mach-omap1/board-ams-delta.c |   24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

--- linux-2.6.35-rc3.orig/arch/arm/mach-omap1/board-ams-delta.c	2010-07-18 02:48:53.000000000 +0200
+++ linux-2.6.35-rc3/arch/arm/mach-omap1/board-ams-delta.c	2010-07-18 02:47:33.000000000 +0200
@@ -16,6 +16,7 @@
 #include <linux/init.h>
 #include <linux/input.h>
 #include <linux/interrupt.h>
+#include <linux/leds.h>
 #include <linux/platform_device.h>
 #include <linux/serial_8250.h>
 
@@ -222,11 +223,30 @@ static struct i2c_board_info ams_delta_c
 	},
 };
 
+#if defined(CONFIG_LEDS_TRIGGERS)
+DEFINE_LED_TRIGGER(ams_delta_camera_led_trigger);
+
+static int ams_delta_camera_power(struct device *dev, int power)
+{
+	/*
+	 * turn on camera LED
+	 */
+	if (power)
+		led_trigger_event(ams_delta_camera_led_trigger, LED_FULL);
+	else
+		led_trigger_event(ams_delta_camera_led_trigger, LED_OFF);
+	return 0;
+}
+#else
+#define ams_delta_camera_power	NULL
+#endif
+
 static struct soc_camera_link __initdata ams_delta_iclink = {
 	.bus_id         = 0,	/* OMAP1 SoC camera bus */
 	.i2c_adapter_id = 1,
 	.board_info     = &ams_delta_camera_board_info[0],
 	.module_name    = "ov6650",
+	.power		= ams_delta_camera_power,
 };
 
 static struct platform_device ams_delta_camera_device = {
@@ -281,6 +301,10 @@ static void __init ams_delta_init(void)
 
 	omap_usb_init(&ams_delta_usb_config);
 	omap1_set_camera_info(&ams_delta_camera_platform_data);
+#if defined(CONFIG_LEDS_TRIGGERS)
+	led_trigger_register_simple("ams_delta_camera",
+			&ams_delta_camera_led_trigger);
+#endif
 	platform_add_devices(ams_delta_devices, ARRAY_SIZE(ams_delta_devices));
 
 #ifdef CONFIG_AMS_DELTA_FIQ

Re: [RFC] [PATCH 0/6] Add camera support to the OMAP1 Amstrad Delta videophone

[Guennadi Liakhovetski]

Hi Janusz

On Sun, 18 Jul 2010, Janusz Krzysztofik wrote:

> This series consists of the following patches:
> 
>   1/6	SoC Camera: add driver for OMAP1 camera interface
>   2/6	OMAP1: Add support for SoC camera interface
>   3/6	SoC Camera: add driver for OV6650 sensor
>   4/6	SoC Camera: add support for g_parm / s_parm operations
>   5/6	OMAP1: Amstrad Delta: add support for on-board camera
>   6/6	OMAP1: Amstrad Delta: add camera controlled LEDS trigger

It is an interesting decision to use soc-camera for an OMAP SoC, as you 
most probably know OMAP3 and OMAP2 camera drivers do not use soc-camera. I 
certainly do not want to discourage you from using soc-camera, just don't 
want you to go the wrong way and then regret it or spend time re-designing 
your driver. Have you had specific reasons for this design? Is OMAP1 so 
different from 2 (and 3)? In any case - thanks for the patches, if you do 
insist on going this path (;)) I'll review them and get back to you after 
that. Beware, it might be difficult to finish the review process in time 
for 2.6.36...

Thanks
Guennadi

> 
>  arch/arm/mach-omap1/board-ams-delta.c     |   69 +
>  arch/arm/mach-omap1/devices.c             |   43
>  arch/arm/mach-omap1/include/mach/camera.h |    8
>  drivers/media/video/Kconfig               |   20
>  drivers/media/video/Makefile              |    2
>  drivers/media/video/omap1_camera.c        | 1656 ++++++++++++++++++++++++++++++
>  drivers/media/video/ov6650.c              | 1336 ++++++++++++++++++++++++
>  drivers/media/video/soc_camera.c          |   18
>  include/media/omap1_camera.h              |   16
>  include/media/v4l2-chip-ident.h           |    1
>  10 files changed, 3169 insertions(+)
> 
> Thanks,
> Janusz
> 

---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/

Re: [RFC] [PATCH 0/6] Add camera support to the OMAP1 Amstrad Delta videophone

[Janusz Krzysztofik]

Tuesday 20 July 2010 11:49:54 Guennadi Liakhovetski wrote:
> Hi Janusz

Hi Guennadi,
Thanks for your answer.

> On Sun, 18 Jul 2010, Janusz Krzysztofik wrote:
> > This series consists of the following patches:
> >
> >   1/6	SoC Camera: add driver for OMAP1 camera interface
> >   2/6	OMAP1: Add support for SoC camera interface
> >   3/6	SoC Camera: add driver for OV6650 sensor
> >   4/6	SoC Camera: add support for g_parm / s_parm operations
> >   5/6	OMAP1: Amstrad Delta: add support for on-board camera
> >   6/6	OMAP1: Amstrad Delta: add camera controlled LEDS trigger
>
> It is an interesting decision to use soc-camera for an OMAP SoC, as you
> most probably know OMAP3 and OMAP2 camera drivers do not use soc-camera. I
> certainly do not want to discourage you from using soc-camera, just don't
> want you to go the wrong way and then regret it or spend time re-designing
> your driver. 

If this way occures wrong, then it's only my fault, since I've taken it 
myself, without consulting it neither on omap nor media list, so I'm not 
going to blame anyone except myself.

> Have you had specific reasons for this design? 

It looked like the most simple way for me. And while implementing it, I 
haven't faced any restrictions that would lead me to changing my mind and 
doing it another way.

> Is OMAP1 so different from 2 (and 3)? 

I think so, but let's see what OMAP guys have to say.

> In any case - thanks for the patches, if you do 
> insist on going this path (;)) I'll review them and get back to you after
> that. Beware, it might be difficult to finish the review process in time
> for 2.6.36...

Since not all patches from the series are OMAP related, and those that are 
not, don't depend on others, I think you could have a look at 4/6 and see if 
it makes sense or not. You could also examine 6/6 and see if you would like 
the idea of a camera LED trigger implemented, this way or another, at the 
soc_camera framework level rather than specific machine or platform. Last, 
the sensor driver (3/6), even if soc_camera specific, could be considered, if 
accepted, for adopting it as a regular v4l2-subdev, if required by a 
different implementation of OMAP part choosen.

Thanks,
Janusz