[PATCH 16/20] media: imx: Add MIPI CSI-2 Receiver subdev driver

[Steve Longerbeam <slongerbeam-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

Adds MIPI CSI-2 Receiver subdev driver. This subdev is required
for sensors with a MIPI CSI2 interface.

Signed-off-by: Steve Longerbeam <steve_longerbeam-nmGgyN9QBj3QT0dZR+AlfA@public.gmane.org>
---
 drivers/staging/media/imx/Makefile        |   1 +
 drivers/staging/media/imx/imx-mipi-csi2.c | 509 ++++++++++++++++++++++++++++++
 2 files changed, 510 insertions(+)
 create mode 100644 drivers/staging/media/imx/imx-mipi-csi2.c

diff --git a/drivers/staging/media/imx/Makefile b/drivers/staging/media/imx/Makefile
index fe9e992..0decef7 100644
--- a/drivers/staging/media/imx/Makefile
+++ b/drivers/staging/media/imx/Makefile
@@ -9,3 +9,4 @@ obj-$(CONFIG_VIDEO_IMX_MEDIA) += imx-ic.o
 obj-$(CONFIG_VIDEO_IMX_CAMERA) += imx-csi.o
 obj-$(CONFIG_VIDEO_IMX_CAMERA) += imx-smfc.o
 obj-$(CONFIG_VIDEO_IMX_CAMERA) += imx-camif.o
+obj-$(CONFIG_VIDEO_IMX_CAMERA) += imx-mipi-csi2.o
diff --git a/drivers/staging/media/imx/imx-mipi-csi2.c b/drivers/staging/media/imx/imx-mipi-csi2.c
new file mode 100644
index 0000000..84df16e
--- /dev/null
+++ b/drivers/staging/media/imx/imx-mipi-csi2.c
@@ -0,0 +1,509 @@
+/*
+ * MIPI CSI-2 Receiver Subdev for Freescale i.MX5/6 SOC.
+ *
+ * Copyright (c) 2012-2014 Mentor Graphics Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+#include <linux/module.h>
+#include <linux/export.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/list.h>
+#include <linux/irq.h>
+#include <linux/of_device.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-of.h>
+#include <media/v4l2-subdev.h>
+#include <media/v4l2-async.h>
+#include <asm/mach/irq.h>
+#include <video/imx-ipu-v3.h>
+#include "imx-media.h"
+
+/*
+ * there must be 5 pads: 1 input pad from sensor, and
+ * the 4 virtual channel output pads
+ */
+#define CSI2_NUM_SINK_PADS  1
+#define CSI2_NUM_SRC_PADS   4
+#define CSI2_NUM_PADS       5
+
+struct imxcsi2_dev {
+	struct device          *dev;
+	struct imx_media_dev   *md;
+	struct v4l2_subdev      sd;
+	struct media_pad       pad[CSI2_NUM_PADS];
+	struct v4l2_mbus_framefmt format_mbus;
+	struct v4l2_subdev     *src_sd;
+	struct v4l2_subdev     *sink_sd[CSI2_NUM_SRC_PADS];
+	int                    input_pad;
+	struct clk             *dphy_clk;
+	struct clk             *cfg_clk;
+	struct clk             *pix_clk; /* what is this? */
+	void __iomem           *base;
+	int                     intr1;
+	int                     intr2;
+	struct v4l2_of_bus_mipi_csi2 bus;
+	bool                    on;
+	bool                    stream_on;
+};
+
+#define DEVICE_NAME "imx-mipi-csi2"
+
+/* Register offsets */
+#define CSI2_VERSION            0x000
+#define CSI2_N_LANES            0x004
+#define CSI2_PHY_SHUTDOWNZ      0x008
+#define CSI2_DPHY_RSTZ          0x00c
+#define CSI2_RESETN             0x010
+#define CSI2_PHY_STATE          0x014
+#define CSI2_DATA_IDS_1         0x018
+#define CSI2_DATA_IDS_2         0x01c
+#define CSI2_ERR1               0x020
+#define CSI2_ERR2               0x024
+#define CSI2_MSK1               0x028
+#define CSI2_MSK2               0x02c
+#define CSI2_PHY_TST_CTRL0      0x030
+#define CSI2_PHY_TST_CTRL1      0x034
+#define CSI2_SFT_RESET          0xf00
+
+static inline struct imxcsi2_dev *sd_to_dev(struct v4l2_subdev *sdev)
+{
+	return container_of(sdev, struct imxcsi2_dev, sd);
+}
+
+static inline u32 imxcsi2_read(struct imxcsi2_dev *csi2, unsigned int regoff)
+{
+	return readl(csi2->base + regoff);
+}
+
+static inline void imxcsi2_write(struct imxcsi2_dev *csi2, u32 val,
+				 unsigned int regoff)
+{
+	writel(val, csi2->base + regoff);
+}
+
+static void imxcsi2_set_lanes(struct imxcsi2_dev *csi2)
+{
+	int lanes = csi2->bus.num_data_lanes;
+
+	imxcsi2_write(csi2, lanes - 1, CSI2_N_LANES);
+}
+
+static void imxcsi2_enable(struct imxcsi2_dev *csi2, bool enable)
+{
+	if (enable) {
+		imxcsi2_write(csi2, 0xffffffff, CSI2_PHY_SHUTDOWNZ);
+		imxcsi2_write(csi2, 0xffffffff, CSI2_DPHY_RSTZ);
+		imxcsi2_write(csi2, 0xffffffff, CSI2_RESETN);
+	} else {
+		imxcsi2_write(csi2, 0x0, CSI2_PHY_SHUTDOWNZ);
+		imxcsi2_write(csi2, 0x0, CSI2_DPHY_RSTZ);
+		imxcsi2_write(csi2, 0x0, CSI2_RESETN);
+	}
+}
+
+static void imxcsi2_reset(struct imxcsi2_dev *csi2)
+{
+	imxcsi2_enable(csi2, false);
+
+	imxcsi2_write(csi2, 0x00000001, CSI2_PHY_TST_CTRL0);
+	imxcsi2_write(csi2, 0x00000000, CSI2_PHY_TST_CTRL1);
+	imxcsi2_write(csi2, 0x00000000, CSI2_PHY_TST_CTRL0);
+	imxcsi2_write(csi2, 0x00000002, CSI2_PHY_TST_CTRL0);
+	imxcsi2_write(csi2, 0x00010044, CSI2_PHY_TST_CTRL1);
+	imxcsi2_write(csi2, 0x00000000, CSI2_PHY_TST_CTRL0);
+	imxcsi2_write(csi2, 0x00000014, CSI2_PHY_TST_CTRL1);
+	imxcsi2_write(csi2, 0x00000002, CSI2_PHY_TST_CTRL0);
+	imxcsi2_write(csi2, 0x00000000, CSI2_PHY_TST_CTRL0);
+
+	imxcsi2_enable(csi2, true);
+}
+
+static int imxcsi2_dphy_wait(struct imxcsi2_dev *csi2)
+{
+	u32 reg;
+	int i;
+
+	/* wait for mipi sensor ready */
+	for (i = 0; i < 50; i++) {
+		reg = imxcsi2_read(csi2, CSI2_PHY_STATE);
+		if (reg != 0x200)
+			break;
+		usleep_range(10000, 20000);
+	}
+
+	if (i >= 50) {
+		v4l2_err(&csi2->sd,
+			 "wait for clock lane timeout, phy_state = 0x%08x\n",
+			 reg);
+		return -ETIME;
+	}
+
+	/* wait for mipi stable */
+	for (i = 0; i < 50; i++) {
+		reg = imxcsi2_read(csi2, CSI2_ERR1);
+		if (reg == 0x0)
+			break;
+		usleep_range(10000, 20000);
+	}
+
+	if (i >= 50) {
+		v4l2_err(&csi2->sd,
+			 "wait for controller timeout, err1 = 0x%08x\n",
+			 reg);
+		return -ETIME;
+	}
+
+	/* finally let's wait for active clock on the clock lane */
+	for (i = 0; i < 50; i++) {
+		reg = imxcsi2_read(csi2, CSI2_PHY_STATE);
+		if (reg & (1 << 8))
+			break;
+		usleep_range(10000, 20000);
+	}
+
+	if (i >= 50) {
+		v4l2_err(&csi2->sd,
+			 "wait for active clock timeout, phy_state = 0x%08x\n",
+			 reg);
+		return -ETIME;
+	}
+
+	v4l2_info(&csi2->sd, "ready, dphy version 0x%x\n",
+		  imxcsi2_read(csi2, CSI2_VERSION));
+
+	return 0;
+}
+
+/*
+ * V4L2 subdev operations
+ */
+
+static int imxcsi2_link_setup(struct media_entity *entity,
+			      const struct media_pad *local,
+			      const struct media_pad *remote, u32 flags)
+{
+	struct v4l2_subdev *sd = media_entity_to_v4l2_subdev(entity);
+	struct imxcsi2_dev *csi2 = sd_to_dev(sd);
+	struct v4l2_subdev *remote_sd;
+
+	dev_dbg(csi2->dev, "link setup %s -> %s", remote->entity->name,
+		local->entity->name);
+
+	remote_sd = media_entity_to_v4l2_subdev(remote->entity);
+
+	if (local->flags & MEDIA_PAD_FL_SOURCE) {
+		if (flags & MEDIA_LNK_FL_ENABLED) {
+			if (csi2->sink_sd[local->index])
+				return -EBUSY;
+			csi2->sink_sd[local->index] = remote_sd;
+		} else {
+			csi2->sink_sd[local->index] = NULL;
+		}
+	} else {
+		if (flags & MEDIA_LNK_FL_ENABLED) {
+			if (csi2->src_sd)
+				return -EBUSY;
+			csi2->src_sd = remote_sd;
+		} else {
+			csi2->src_sd = NULL;
+		}
+	}
+
+	return 0;
+}
+
+static int imxcsi2_s_power(struct v4l2_subdev *sd, int on)
+{
+	struct imxcsi2_dev *csi2 = sd_to_dev(sd);
+
+	if (on && !csi2->on) {
+		v4l2_info(&csi2->sd, "power ON\n");
+		clk_prepare_enable(csi2->cfg_clk);
+		clk_prepare_enable(csi2->dphy_clk);
+		imxcsi2_set_lanes(csi2);
+		imxcsi2_reset(csi2);
+	} else if (!on && csi2->on) {
+		v4l2_info(&csi2->sd, "power OFF\n");
+		imxcsi2_enable(csi2, false);
+		clk_disable_unprepare(csi2->dphy_clk);
+		clk_disable_unprepare(csi2->cfg_clk);
+	}
+
+	csi2->on = on;
+	return 0;
+}
+
+static int imxcsi2_s_stream(struct v4l2_subdev *sd, int enable)
+{
+	struct imxcsi2_dev *csi2 = sd_to_dev(sd);
+	int i, ret = 0;
+
+	if (!csi2->src_sd)
+		return -EPIPE;
+	for (i = 0; i < CSI2_NUM_SRC_PADS; i++) {
+		if (csi2->sink_sd[i])
+			break;
+	}
+	if (i >= CSI2_NUM_SRC_PADS)
+		return -EPIPE;
+
+	v4l2_info(sd, "stream %s\n", enable ? "ON" : "OFF");
+
+	if (enable && !csi2->stream_on) {
+		clk_prepare_enable(csi2->pix_clk);
+		ret = imxcsi2_dphy_wait(csi2);
+		if (ret)
+			clk_disable_unprepare(csi2->pix_clk);
+	} else if (!enable && csi2->stream_on) {
+		clk_disable_unprepare(csi2->pix_clk);
+	}
+
+	if (!ret)
+		csi2->stream_on = enable;
+	return ret;
+}
+
+static int imxcsi2_get_fmt(struct v4l2_subdev *sd,
+			   struct v4l2_subdev_pad_config *cfg,
+			   struct v4l2_subdev_format *sdformat)
+{
+	struct imxcsi2_dev *csi2 = sd_to_dev(sd);
+
+	sdformat->format = csi2->format_mbus;
+
+	return 0;
+}
+
+static int imxcsi2_set_fmt(struct v4l2_subdev *sd,
+			   struct v4l2_subdev_pad_config *cfg,
+			   struct v4l2_subdev_format *sdformat)
+{
+	struct imxcsi2_dev *csi2 = sd_to_dev(sd);
+
+	if (sdformat->pad >= CSI2_NUM_PADS)
+		return -EINVAL;
+
+	if (csi2->stream_on)
+		return -EBUSY;
+
+	/* Output pads mirror active input pad, no limits on input pads */
+	if (sdformat->pad != csi2->input_pad)
+		sdformat->format = csi2->format_mbus;
+
+	if (sdformat->which == V4L2_SUBDEV_FORMAT_TRY)
+		cfg->try_fmt = sdformat->format;
+	else
+		csi2->format_mbus = sdformat->format;
+
+	return 0;
+}
+
+/*
+ * retrieve our pads parsed from the OF graph by the media device
+ */
+static int imxcsi2_registered(struct v4l2_subdev *sd)
+{
+	struct imxcsi2_dev *csi2 = sd_to_dev(sd);
+	struct imx_media_subdev *imxsd;
+	struct imx_media_pad *pad;
+	int i, ret;
+
+	/* get media device */
+	csi2->md = dev_get_drvdata(sd->v4l2_dev->dev);
+
+	imxsd = imx_media_find_subdev_by_sd(csi2->md, sd);
+	if (IS_ERR(imxsd))
+		return PTR_ERR(imxsd);
+
+	if (imxsd->num_sink_pads != 1 || imxsd->num_src_pads != 4)
+		return -EINVAL;
+
+	for (i = 0; i < CSI2_NUM_PADS; i++) {
+		pad = &imxsd->pad[i];
+		csi2->pad[i] = pad->pad;
+		if (csi2->pad[i].flags & MEDIA_PAD_FL_SINK)
+			csi2->input_pad = i;
+	}
+
+	/* set a default mbus format  */
+	ret = imx_media_init_mbus_fmt(&csi2->format_mbus,
+				      640, 480, 0, V4L2_FIELD_NONE, NULL);
+	if (ret)
+		return ret;
+
+	return media_entity_pads_init(&sd->entity, CSI2_NUM_PADS, csi2->pad);
+}
+
+static struct media_entity_operations imxcsi2_entity_ops = {
+	.link_setup = imxcsi2_link_setup,
+	.link_validate = v4l2_subdev_link_validate,
+};
+
+static struct v4l2_subdev_core_ops imxcsi2_core_ops = {
+	.s_power = imxcsi2_s_power,
+};
+
+static struct v4l2_subdev_video_ops imxcsi2_video_ops = {
+	.s_stream = imxcsi2_s_stream,
+};
+
+static struct v4l2_subdev_pad_ops imxcsi2_pad_ops = {
+	.get_fmt = imxcsi2_get_fmt,
+	.set_fmt = imxcsi2_set_fmt,
+};
+
+static struct v4l2_subdev_ops imxcsi2_subdev_ops = {
+	.core = &imxcsi2_core_ops,
+	.video = &imxcsi2_video_ops,
+	.pad = &imxcsi2_pad_ops,
+};
+
+static struct v4l2_subdev_internal_ops imxcsi2_internal_ops = {
+	.registered = imxcsi2_registered,
+};
+
+static int imxcsi2_parse_endpoints(struct imxcsi2_dev *csi2)
+{
+	struct device_node *node = csi2->dev->of_node;
+	struct device_node *epnode;
+	struct v4l2_of_endpoint ep;
+	int ret = 0;
+
+	epnode = of_graph_get_next_endpoint(node, NULL);
+	if (!epnode) {
+		v4l2_err(&csi2->sd, "failed to get endpoint node\n");
+		return -EINVAL;
+	}
+
+	v4l2_of_parse_endpoint(epnode, &ep);
+	if (ep.bus_type != V4L2_MBUS_CSI2) {
+		v4l2_err(&csi2->sd, "invalid bus type, must be MIPI CSI2\n");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	csi2->bus = ep.bus.mipi_csi2;
+
+	v4l2_info(&csi2->sd, "data lanes: %d\n", csi2->bus.num_data_lanes);
+	v4l2_info(&csi2->sd, "flags: 0x%08x\n", csi2->bus.flags);
+out:
+	of_node_put(epnode);
+	return ret;
+}
+
+static int imxcsi2_probe(struct platform_device *pdev)
+{
+	struct imxcsi2_dev *csi2;
+	struct resource *res;
+	int ret;
+
+	csi2 = devm_kzalloc(&pdev->dev, sizeof(*csi2), GFP_KERNEL);
+	if (!csi2)
+		return -ENOMEM;
+
+	csi2->dev = &pdev->dev;
+
+	v4l2_subdev_init(&csi2->sd, &imxcsi2_subdev_ops);
+	v4l2_set_subdevdata(&csi2->sd, &pdev->dev);
+	csi2->sd.internal_ops = &imxcsi2_internal_ops;
+	csi2->sd.entity.ops = &imxcsi2_entity_ops;
+	csi2->sd.dev = &pdev->dev;
+	csi2->sd.owner = THIS_MODULE;
+	csi2->sd.flags = V4L2_SUBDEV_FL_HAS_DEVNODE;
+	strcpy(csi2->sd.name, DEVICE_NAME);
+	/* FIXME: this is a mipi-csi2 receiver, function isn't right */
+	csi2->sd.entity.function = MEDIA_ENT_F_ATV_DECODER;
+	csi2->sd.grp_id = IMX_MEDIA_GRP_ID_CSI2;
+
+	ret = imxcsi2_parse_endpoints(csi2);
+	if (ret)
+		return ret;
+
+	csi2->cfg_clk = devm_clk_get(&pdev->dev, "cfg_clk");
+	if (IS_ERR(csi2->cfg_clk)) {
+		v4l2_err(&csi2->sd, "failed to get cfg clock\n");
+		ret = PTR_ERR(csi2->cfg_clk);
+		return ret;
+	}
+
+	csi2->dphy_clk = devm_clk_get(&pdev->dev, "dphy_clk");
+	if (IS_ERR(csi2->dphy_clk)) {
+		v4l2_err(&csi2->sd, "failed to get dphy clock\n");
+		ret = PTR_ERR(csi2->dphy_clk);
+		return ret;
+	}
+
+	csi2->pix_clk = devm_clk_get(&pdev->dev, "pix_clk");
+	if (IS_ERR(csi2->pix_clk)) {
+		v4l2_err(&csi2->sd, "failed to get pixel clock\n");
+		ret = PTR_ERR(csi2->pix_clk);
+		return ret;
+	}
+
+	csi2->intr1 = platform_get_irq(pdev, 0);
+	csi2->intr2 = platform_get_irq(pdev, 1);
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+	if (!res || csi2->intr1 < 0 || csi2->intr2 < 0) {
+		v4l2_err(&csi2->sd, "failed to get platform resources\n");
+		return -ENODEV;
+	}
+
+	csi2->base = devm_ioremap(&pdev->dev, res->start, PAGE_SIZE);
+	if (!csi2->base) {
+		v4l2_err(&csi2->sd, "failed to map CSI-2 registers\n");
+		return -ENOMEM;
+	}
+
+	platform_set_drvdata(pdev, &csi2->sd);
+
+	return v4l2_async_register_subdev(&csi2->sd);
+}
+
+static int imxcsi2_remove(struct platform_device *pdev)
+{
+	struct v4l2_subdev *sd = platform_get_drvdata(pdev);
+	struct imxcsi2_dev *csi2 = sd_to_dev(sd);
+
+	imxcsi2_s_power(sd, 0);
+
+	v4l2_async_unregister_subdev(&csi2->sd);
+	media_entity_cleanup(&csi2->sd.entity);
+	v4l2_device_unregister_subdev(sd);
+
+	return 0;
+}
+
+static const struct of_device_id imxcsi2_dt_ids[] = {
+	{ .compatible = "fsl,imx-mipi-csi2", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, imxcsi2_dt_ids);
+
+static struct platform_driver imxcsi2_driver = {
+	.driver = {
+		.name = DEVICE_NAME,
+		.owner = THIS_MODULE,
+		.of_match_table = imxcsi2_dt_ids,
+	},
+	.probe = imxcsi2_probe,
+	.remove = imxcsi2_remove,
+};
+
+module_platform_driver(imxcsi2_driver);
+
+MODULE_DESCRIPTION("i.MX5/6 MIPI CSI-2 Receiver driver");
+MODULE_AUTHOR("Steve Longerbeam <steve_longerbeam-nmGgyN9QBj3QT0dZR+AlfA@public.gmane.org>");
+MODULE_LICENSE("GPL");
+
-- 
2.7.4

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