[RFC 2.6.27 1/2] fbdev: add E-Ink Broadsheet controller support

[RFC 2.6.27 1/2] fbdev: add E-Ink Broadsheet controller support

[Jaya Kumar]

Hi arm, fbdev friends,

Just reposting this RFC after splitting it into 2 separate patches, 1 to add
broadsheetfb and another to add am300 support. Please let me know your
feedback. If there aren't any complaints, then I think I'll post to the
rmk patch queue. The am300 patch is dependent on the gumstix cleanup merged
from Eric's pxa tree.

Thanks,
jaya


This patch adds support for the E-Ink Broadsheet display controller

Signed-off-by: Jaya Kumar <jayakumar.lkml@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Eric Miao <eric.miao@marvell.com>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Cc: linux-fbdev-devel@lists.sourceforge.net
Cc: linux-arm-kernel@lists.arm.linux.org.uk
---
 drivers/video/Kconfig        |   14 +
 drivers/video/Makefile       |    1 +
 drivers/video/broadsheetfb.c |  569 ++++++++++++++++++++++++++++++++++++++++++
 include/video/broadsheetfb.h |   63 +++++
 4 files changed, 647 insertions(+), 0 deletions(-)
 create mode 100644 drivers/video/broadsheetfb.c
 create mode 100644 include/video/broadsheetfb.h

diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 3f3ce13..053f5f9 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -2115,6 +2115,20 @@ config FB_PRE_INIT_FB
 	  Select this option if display contents should be inherited as set by
 	  the bootloader.
 
+config FB_BROADSHEET
+	tristate "E-Ink Broadsheet/Epson S1D13521 controller support"
+	depends on FB
+	select FB_SYS_FILLRECT
+	select FB_SYS_COPYAREA
+	select FB_SYS_IMAGEBLIT
+	select FB_SYS_FOPS
+	select FB_DEFERRED_IO
+	help
+	  This driver implements support for the E-Ink Broadsheet
+	  controller. The release name for this device was Epson S1D13521
+	  and could also have been called by other names when coupled with
+	  a bridge adapter.
+
 source "drivers/video/omap/Kconfig"
 
 source "drivers/video/backlight/Kconfig"
diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index e39e33e..ee9ed00 100644
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -106,6 +106,7 @@ obj-$(CONFIG_FB_PMAG_BA)	  += pmag-ba-fb.o
 obj-$(CONFIG_FB_PMAGB_B)	  += pmagb-b-fb.o
 obj-$(CONFIG_FB_MAXINE)		  += maxinefb.o
 obj-$(CONFIG_FB_METRONOME)        += metronomefb.o
+obj-$(CONFIG_FB_BROADSHEET)       += broadsheetfb.o
 obj-$(CONFIG_FB_S1D13XXX)	  += s1d13xxxfb.o
 obj-$(CONFIG_FB_SH7760)		  += sh7760fb.o
 obj-$(CONFIG_FB_IMX)              += imxfb.o
diff --git a/drivers/video/broadsheetfb.c b/drivers/video/broadsheetfb.c
new file mode 100644
index 0000000..98f8fd5
--- /dev/null
+++ b/drivers/video/broadsheetfb.c
@@ -0,0 +1,569 @@
+/*
+ * broadsheetfb.c -- FB driver for E-Ink Broadsheet controller
+ *
+ * Copyright (C) 2008, Jaya Kumar
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file COPYING in the main directory of this archive for
+ * more details.
+ *
+ * Layout is based on skeletonfb.c by James Simmons and Geert Uytterhoeven.
+ *
+ * This driver is written to be used with the Broadsheet display controller.
+ *
+ * It is intended to be architecture independent. A board specific driver
+ * must be used to perform all the physical IO interactions.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/fb.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/list.h>
+#include <linux/uaccess.h>
+
+#include <video/broadsheetfb.h>
+
+/* Display specific information */
+#define DPY_W 800
+#define DPY_H 600
+
+static struct fb_fix_screeninfo broadsheetfb_fix __devinitdata = {
+	.id =		"broadsheetfb",
+	.type =		FB_TYPE_PACKED_PIXELS,
+	.visual =	FB_VISUAL_STATIC_PSEUDOCOLOR,
+	.xpanstep =	0,
+	.ypanstep =	0,
+	.ywrapstep =	0,
+	.line_length =	DPY_W,
+	.accel =	FB_ACCEL_NONE,
+};
+
+static struct fb_var_screeninfo broadsheetfb_var __devinitdata = {
+	.xres		= DPY_W,
+	.yres		= DPY_H,
+	.xres_virtual	= DPY_W,
+	.yres_virtual	= DPY_H,
+	.bits_per_pixel	= 8,
+	.grayscale	= 1,
+	.nonstd		= 1,
+	.red =		{ 0, 4, 0 },
+	.green =	{ 0, 4, 0 },
+	.blue =		{ 0, 4, 0 },
+	.transp =	{ 0, 0, 0 },
+};
+
+/* main broadsheetfb functions */
+static void broadsheet_issue_data(struct broadsheetfb_par *par, u16 data)
+{
+	par->board->set_ctl(par, BS_WR, 0);
+	par->board->set_hdb(par, data);
+	par->board->set_ctl(par, BS_WR, 1);
+}
+
+static void broadsheet_issue_cmd(struct broadsheetfb_par *par, u16 data)
+{
+	par->board->set_ctl(par, BS_DC, 0);
+	broadsheet_issue_data(par, data);
+}
+
+static void broadsheet_send_command(struct broadsheetfb_par *par, u16 data)
+{
+	par->board->wait_for_rdy(par);
+
+	par->board->set_ctl(par, BS_CS, 0);
+	broadsheet_issue_cmd(par, data);
+	par->board->set_ctl(par, BS_DC, 1);
+	par->board->set_ctl(par, BS_CS, 1);
+}
+
+static void broadsheet_send_cmdargs(struct broadsheetfb_par *par, u16 cmd,
+					int argc, u16 *argv)
+{
+	int i;
+
+	par->board->wait_for_rdy(par);
+
+	par->board->set_ctl(par, BS_CS, 0);
+	broadsheet_issue_cmd(par, cmd);
+	par->board->set_ctl(par, BS_DC, 1);
+
+	for (i = 0; i < argc; i++)
+		broadsheet_issue_data(par, argv[i]);
+	par->board->set_ctl(par, BS_CS, 1);
+}
+
+static void broadsheet_burst_write(struct broadsheetfb_par *par, int size,
+					u16 *data)
+{
+	int i;
+	u16 tmp;
+
+	par->board->set_ctl(par, BS_CS, 0);
+	par->board->set_ctl(par, BS_DC, 1);
+
+	for (i = 0; i < size; i++) {
+		par->board->set_ctl(par, BS_WR, 0);
+		tmp = (data[i] & 0x0F) << 4;
+		tmp |= (data[i] & 0x0F00) << 4;
+		par->board->set_hdb(par, tmp);
+		par->board->set_ctl(par, BS_WR, 1);
+	}
+
+	par->board->set_ctl(par, BS_CS, 1);
+}
+
+static u16 broadsheet_get_data(struct broadsheetfb_par *par)
+{
+	u16 res;
+	/* wait for ready to go hi. (lo is busy) */
+	par->board->wait_for_rdy(par);
+
+	/* cs lo, dc lo for cmd, we lo for each data, db as usual */
+	par->board->set_ctl(par, BS_DC, 1);
+	par->board->set_ctl(par, BS_CS, 0);
+	par->board->set_ctl(par, BS_WR, 0);
+
+	res = par->board->get_hdb(par);
+
+	/* strobe wr */
+	par->board->set_ctl(par, BS_WR, 1);
+	par->board->set_ctl(par, BS_CS, 1);
+
+	return res;
+}
+
+static void broadsheet_write_reg(struct broadsheetfb_par *par, u16 reg,
+					u16 data)
+{
+	/* wait for ready to go hi. (lo is busy) */
+	par->board->wait_for_rdy(par);
+
+	/* cs lo, dc lo for cmd, we lo for each data, db as usual */
+	par->board->set_ctl(par, BS_CS, 0);
+
+	broadsheet_issue_cmd(par, BS_CMD_WR_REG);
+
+	par->board->set_ctl(par, BS_DC, 1);
+
+	broadsheet_issue_data(par, reg);
+	broadsheet_issue_data(par, data);
+
+	par->board->set_ctl(par, BS_CS, 1);
+}
+
+static u16 broadsheet_read_reg(struct broadsheetfb_par *par, u16 reg)
+{
+	broadsheet_send_command(par, reg);
+	mdelay(100);
+	return broadsheet_get_data(par);
+}
+
+static void __devinit broadsheet_init_display(struct broadsheetfb_par *par)
+{
+	u16 args[5];
+
+	args[0] = DPY_W;
+	args[1] = DPY_H;
+	args[2] = (100 | (1 << 8) | (1 << 9)); /* sdcfg */
+	args[3] = 2; /* gdrv cfg */
+	args[4] = (4 | (1 << 7)); /* lut index format */
+	broadsheet_send_cmdargs(par, BS_CMD_INIT_DSPE_CFG, 5, args);
+
+	/* did the controller really set it? */
+	broadsheet_send_cmdargs(par, BS_CMD_INIT_DSPE_CFG, 5, args);
+
+	args[0] = 4; /* fsync len */
+	args[1] = (10 << 8) | 4; /* fend/fbegin len */
+	args[2] = 10; /* line sync len */
+	args[3] = (100 << 8) | 4; /* line end/begin len */
+	args[4] = 6; /* pixel clock cfg */
+	broadsheet_send_cmdargs(par, BS_CMD_INIT_DSPE_TMG, 5, args);
+
+	/* setup waveform */
+	args[0] = 0x886;
+	args[1] = 0;
+	broadsheet_send_cmdargs(par, BS_CMD_RD_WFM_INFO, 2, args);
+
+	broadsheet_send_command(par, BS_CMD_UPD_GDRV_CLR);
+
+	broadsheet_send_command(par, BS_CMD_WAIT_DSPE_TRG);
+
+	broadsheet_write_reg(par, 0x330, 0x84);
+
+	broadsheet_send_command(par, BS_CMD_WAIT_DSPE_TRG);
+
+	args[0] = (0x3 << 4);
+	broadsheet_send_cmdargs(par, BS_CMD_LD_IMG, 1, args);
+
+	args[0] = 0x154;
+	broadsheet_send_cmdargs(par, BS_CMD_WR_REG, 1, args);
+
+	broadsheet_burst_write(par, DPY_W*DPY_H/2,
+				(u16 *) par->info->screen_base);
+
+	broadsheet_send_command(par, BS_CMD_LD_IMG_END);
+
+	args[0] = 0x4300;
+	broadsheet_send_cmdargs(par, BS_CMD_UPD_FULL, 1, args);
+
+	broadsheet_send_command(par, BS_CMD_WAIT_DSPE_TRG);
+
+	broadsheet_send_command(par, BS_CMD_WAIT_DSPE_FREND);
+
+	par->board->wait_for_rdy(par);
+}
+
+static void __devinit broadsheet_init(struct broadsheetfb_par *par)
+{
+	broadsheet_send_command(par, BS_CMD_INIT_SYS_RUN);
+	/* the controller needs a second */
+	mdelay(1000);
+	broadsheet_init_display(par);
+}
+
+static void broadsheetfb_dpy_update_pages(struct broadsheetfb_par *par,
+						u16 y1, u16 y2)
+{
+	u16 args[5];
+	unsigned char *buf = (unsigned char __force *)par->info->screen_base;
+
+	/* y1 must be a multiple of 4 so drop the lower bits */
+	y1 &= 0xFFFC;
+	/* y2 must be a multiple of 4 , but - 1 so up the lower bits */
+	y2 |= 0x0003;
+
+	args[0] = 0x3 << 4;
+	args[1] = 0;
+	args[2] = y1;
+	args[3] = cpu_to_le16(par->info->var.xres);
+	args[4] = y2;
+	broadsheet_send_cmdargs(par, BS_CMD_LD_IMG_AREA, 5, args);
+
+	args[0] = 0x154;
+	broadsheet_send_cmdargs(par, BS_CMD_WR_REG, 1, args);
+
+	buf += y1 * par->info->var.xres;
+	broadsheet_burst_write(par, ((1 + y2 - y1) * par->info->var.xres)/2,
+				(u16 *) buf);
+
+	broadsheet_send_command(par, BS_CMD_LD_IMG_END);
+
+	args[0] = 0x4300;
+	broadsheet_send_cmdargs(par, BS_CMD_UPD_FULL, 1, args);
+
+	broadsheet_send_command(par, BS_CMD_WAIT_DSPE_TRG);
+
+	broadsheet_send_command(par, BS_CMD_WAIT_DSPE_FREND);
+
+	par->board->wait_for_rdy(par);
+
+}
+
+static void broadsheetfb_dpy_update(struct broadsheetfb_par *par)
+{
+	u16 args[5];
+
+	args[0] = 0x3 << 4;
+	broadsheet_send_cmdargs(par, BS_CMD_LD_IMG, 1, args);
+
+	args[0] = 0x154;
+	broadsheet_send_cmdargs(par, BS_CMD_WR_REG, 1, args);
+	broadsheet_burst_write(par, DPY_W*DPY_H/2,
+				(u16 *) par->info->screen_base);
+
+	broadsheet_send_command(par, BS_CMD_LD_IMG_END);
+
+	args[0] = 0x4300;
+	broadsheet_send_cmdargs(par, BS_CMD_UPD_FULL, 1, args);
+
+	broadsheet_send_command(par, BS_CMD_WAIT_DSPE_TRG);
+
+	broadsheet_send_command(par, BS_CMD_WAIT_DSPE_FREND);
+
+	par->board->wait_for_rdy(par);
+
+}
+
+/* this is called back from the deferred io workqueue */
+static void broadsheetfb_dpy_deferred_io(struct fb_info *info,
+				struct list_head *pagelist)
+{
+	u16 y1 = 0, h = 0;
+	int prev_index = -1;
+	struct page *cur;
+	struct fb_deferred_io *fbdefio = info->fbdefio;
+	int h_inc;
+	u16 yres = info->var.yres;
+	u16 xres = info->var.xres;
+
+	/* height increment is fixed per page */
+	h_inc = DIV_ROUND_UP(PAGE_SIZE , xres);
+
+	/* walk the written page list and swizzle the data */
+	list_for_each_entry(cur, &fbdefio->pagelist, lru) {
+		if (prev_index < 0) {
+			/* just starting so assign first page */
+			y1 = (cur->index << PAGE_SHIFT) / xres;
+			h = h_inc;
+		} else if ((prev_index + 1) == cur->index) {
+			/* this page is consecutive so increase our height */
+			h += h_inc;
+		} else {
+			/* page not consecutive, issue previous update first */
+			broadsheetfb_dpy_update_pages(info->par, y1, y1 + h);
+			/* start over with our non consecutive page */
+			y1 = (cur->index << PAGE_SHIFT) / xres;
+			h = h_inc;
+		}
+		prev_index = cur->index;
+	}
+
+	/* if we still have any pages to update we do so now */
+	if (h >= yres) {
+		/* its a full screen update, just do it */
+		broadsheetfb_dpy_update(info->par);
+	} else {
+		broadsheetfb_dpy_update_pages(info->par, y1,
+						min((u16) (y1 + h), yres));
+	}
+}
+
+static void broadsheetfb_fillrect(struct fb_info *info,
+				   const struct fb_fillrect *rect)
+{
+	struct broadsheetfb_par *par = info->par;
+
+	sys_fillrect(info, rect);
+
+	broadsheetfb_dpy_update(par);
+}
+
+static void broadsheetfb_copyarea(struct fb_info *info,
+				   const struct fb_copyarea *area)
+{
+	struct broadsheetfb_par *par = info->par;
+
+	sys_copyarea(info, area);
+
+	broadsheetfb_dpy_update(par);
+}
+
+static void broadsheetfb_imageblit(struct fb_info *info,
+				const struct fb_image *image)
+{
+	struct broadsheetfb_par *par = info->par;
+
+	sys_imageblit(info, image);
+
+	broadsheetfb_dpy_update(par);
+}
+
+/*
+ * this is the slow path from userspace. they can seek and write to
+ * the fb. it's inefficient to do anything less than a full screen draw
+ */
+static ssize_t broadsheetfb_write(struct fb_info *info, const char __user *buf,
+				size_t count, loff_t *ppos)
+{
+	struct broadsheetfb_par *par = info->par;
+	unsigned long p = *ppos;
+	void *dst;
+	int err = 0;
+	unsigned long total_size;
+
+	if (info->state != FBINFO_STATE_RUNNING)
+		return -EPERM;
+
+	total_size = info->fix.smem_len;
+
+	if (p > total_size)
+		return -EFBIG;
+
+	if (count > total_size) {
+		err = -EFBIG;
+		count = total_size;
+	}
+
+	if (count + p > total_size) {
+		if (!err)
+			err = -ENOSPC;
+
+		count = total_size - p;
+	}
+
+	dst = (void __force *) (info->screen_base + p);
+
+	if (copy_from_user(dst, buf, count))
+		err = -EFAULT;
+
+	if  (!err)
+		*ppos += count;
+
+	broadsheetfb_dpy_update(par);
+
+	return (err) ? err : count;
+}
+
+static struct fb_ops broadsheetfb_ops = {
+	.owner		= THIS_MODULE,
+	.fb_read        = fb_sys_read,
+	.fb_write	= broadsheetfb_write,
+	.fb_fillrect	= broadsheetfb_fillrect,
+	.fb_copyarea	= broadsheetfb_copyarea,
+	.fb_imageblit	= broadsheetfb_imageblit,
+};
+
+static struct fb_deferred_io broadsheetfb_defio = {
+	.delay		= HZ/4,
+	.deferred_io	= broadsheetfb_dpy_deferred_io,
+};
+
+static int __devinit broadsheetfb_probe(struct platform_device *dev)
+{
+	struct fb_info *info;
+	struct broadsheet_board *board;
+	int retval = -ENOMEM;
+	int videomemorysize;
+	unsigned char *videomemory;
+	struct broadsheetfb_par *par;
+	int i;
+
+	/* pick up board specific routines */
+	board = dev->dev.platform_data;
+	if (!board)
+		return -EINVAL;
+
+	/* try to count device specific driver, if can't, platform recalls */
+	if (!try_module_get(board->owner))
+		return -ENODEV;
+
+	info = framebuffer_alloc(sizeof(struct broadsheetfb_par), &dev->dev);
+	if (!info)
+		goto err;
+
+	videomemorysize = (DPY_W*DPY_H);
+	videomemory = vmalloc(videomemorysize);
+	if (!videomemory)
+		goto err_fb_rel;
+
+	memset(videomemory, 0, videomemorysize);
+
+	info->screen_base = (char __force __iomem *)videomemory;
+	info->fbops = &broadsheetfb_ops;
+
+	info->var = broadsheetfb_var;
+	info->fix = broadsheetfb_fix;
+	info->fix.smem_len = videomemorysize;
+	par = info->par;
+	par->info = info;
+	par->board = board;
+	par->write_reg = broadsheet_write_reg;
+	par->read_reg = broadsheet_read_reg;
+	init_waitqueue_head(&par->waitq);
+
+	info->flags = FBINFO_FLAG_DEFAULT;
+
+	info->fbdefio = &broadsheetfb_defio;
+	fb_deferred_io_init(info);
+
+	retval = fb_alloc_cmap(&info->cmap, 16, 0);
+	if (retval < 0) {
+		dev_err(&dev->dev, "Failed to allocate colormap\n");
+		goto err_vfree;
+	}
+
+	/* set cmap */
+	for (i = 0; i < 16; i++)
+		info->cmap.red[i] = (((2*i)+1)*(0xFFFF))/32;
+	memcpy(info->cmap.green, info->cmap.red, sizeof(u16)*16);
+	memcpy(info->cmap.blue, info->cmap.red, sizeof(u16)*16);
+
+	retval = par->board->setup_irq(info);
+	if (retval < 0)
+		goto err_cmap;
+
+	/* this inits the dpy */
+	retval = board->init(par);
+	if (retval < 0)
+		goto err_free_irq;
+
+	broadsheet_init(par);
+
+	retval = register_framebuffer(info);
+	if (retval < 0)
+		goto err_free_irq;
+	platform_set_drvdata(dev, info);
+
+	printk(KERN_INFO
+	       "fb%d: Broadsheet frame buffer, using %dK of video memory\n",
+	       info->node, videomemorysize >> 10);
+
+
+	return 0;
+
+err_free_irq:
+	board->cleanup(par);
+err_cmap:
+	fb_dealloc_cmap(&info->cmap);
+err_vfree:
+	vfree(videomemory);
+err_fb_rel:
+	framebuffer_release(info);
+err:
+	module_put(board->owner);
+	return retval;
+
+}
+
+static int __devexit broadsheetfb_remove(struct platform_device *dev)
+{
+	struct fb_info *info = platform_get_drvdata(dev);
+
+	if (info) {
+		struct broadsheetfb_par *par = info->par;
+		unregister_framebuffer(info);
+		fb_deferred_io_cleanup(info);
+		par->board->cleanup(par);
+		fb_dealloc_cmap(&info->cmap);
+		vfree((void __force *)info->screen_base);
+		module_put(par->board->owner);
+		framebuffer_release(info);
+	}
+	return 0;
+}
+
+static struct platform_driver broadsheetfb_driver = {
+	.probe	= broadsheetfb_probe,
+	.remove = broadsheetfb_remove,
+	.driver	= {
+		.owner	= THIS_MODULE,
+		.name	= "broadsheetfb",
+	},
+};
+
+static int __init broadsheetfb_init(void)
+{
+	return platform_driver_register(&broadsheetfb_driver);
+}
+
+static void __exit broadsheetfb_exit(void)
+{
+	platform_driver_unregister(&broadsheetfb_driver);
+}
+
+module_init(broadsheetfb_init);
+module_exit(broadsheetfb_exit);
+
+MODULE_DESCRIPTION("fbdev driver for Broadsheet controller");
+MODULE_AUTHOR("Jaya Kumar");
+MODULE_LICENSE("GPL");
diff --git a/include/video/broadsheetfb.h b/include/video/broadsheetfb.h
new file mode 100644
index 0000000..f233537
--- /dev/null
+++ b/include/video/broadsheetfb.h
@@ -0,0 +1,63 @@
+/*
+ * broadsheetfb.h - definitions for the broadsheet framebuffer driver
+ *
+ * Copyright (C) 2008 by Jaya Kumar
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file COPYING in the main directory of this archive for
+ * more details.
+ *
+ */
+
+#ifndef _LINUX_BROADSHEETFB_H_
+#define _LINUX_BROADSHEETFB_H_
+
+/* Broadsheet command defines */
+#define BS_CMD_INIT_SYS_RUN	0x06
+#define BS_CMD_INIT_DSPE_CFG	0x09
+#define BS_CMD_INIT_DSPE_TMG	0x0A
+#define BS_CMD_INIT_ROTMODE	0x0B
+#define BS_CMD_RD_REG		0x10
+#define BS_CMD_WR_REG		0x11
+#define BS_CMD_LD_IMG		0x20
+#define BS_CMD_LD_IMG_AREA	0x22
+#define BS_CMD_LD_IMG_END	0x23
+#define BS_CMD_WAIT_DSPE_TRG	0x28
+#define BS_CMD_WAIT_DSPE_FREND	0x29
+#define BS_CMD_RD_WFM_INFO	0x30
+#define BS_CMD_UPD_INIT		0x32
+#define BS_CMD_UPD_FULL		0x33
+#define BS_CMD_UPD_GDRV_CLR	0x37
+
+/* Broadsheet pin interface specific defines */
+#define BS_CS	0x01
+#define BS_DC 	0x02
+#define BS_WR 	0x03
+
+/* struct used by broadsheet. board specific stuff comes from *board */
+struct broadsheetfb_par {
+	struct fb_info *info;
+	struct broadsheet_board *board;
+	void (*write_reg)(struct broadsheetfb_par *, u16 reg, u16 val);
+	u16 (*read_reg)(struct broadsheetfb_par *, u16 reg);
+	wait_queue_head_t waitq;
+	spinlock_t lock;
+};
+
+/* board specific routines */
+struct broadsheet_board {
+	struct module *owner;
+	int (*init)(struct broadsheetfb_par *);
+	int (*wait_for_rdy)(struct broadsheetfb_par *);
+	int (*wait_for_rdy_lo)(struct broadsheetfb_par *);
+	void (*set_ctl)(struct broadsheetfb_par *, unsigned char, u8);
+	void (*set_hdb)(struct broadsheetfb_par *, u16);
+	u16 (*get_hdb)(struct broadsheetfb_par *);
+	void (*cleanup)(struct broadsheetfb_par *);
+	int (*get_panel_type)(void);
+	int (*setup_irq)(struct fb_info *);
+	int (*wait_event)(struct broadsheetfb_par *);
+	int (*wait_event_intr)(struct broadsheetfb_par *);
+};
+
+#endif
-- 
1.5.2.3


------------------------------------------------------------------------------

Re: [RFC 2.6.27 1/2] fbdev: add E-Ink Broadsheet controller support

[linux]

On Sun, Dec 21, 2008 at 06:59:34PM +0800, Jaya Kumar wrote:
> +static void broadsheetfb_dpy_update_pages(struct broadsheetfb_par *par,
> +						u16 y1, u16 y2)
> +{
> +	u16 args[5];
> +	unsigned char *buf = (unsigned char __force *)par->info->screen_base;

You shouldn't add __force inside drivers.

> +	videomemorysize = (DPY_W*DPY_H);
> +	videomemory = vmalloc(videomemorysize);
> +	if (!videomemory)
> +		goto err_fb_rel;
> +
> +	memset(videomemory, 0, videomemorysize);
> +
> +	info->screen_base = (char __force __iomem *)videomemory;

Ditto.

Also, using vmalloc for the backing store means this memory can't be
mmap()'d into userspace, which is a very common thing for framebuffer
using programs to do.  If mmap() is to be denied, then you should
provide a mmap implementation in the fb_ops structure.

------------------------------------------------------------------------------

Re: [RFC 2.6.27 1/2] fbdev: add E-Ink Broadsheet controller support

[Jaya Kumar]

On Sun, Dec 21, 2008 at 6:06 AM,  <linux@arm.linux.org.uk> wrote:
> On Sun, Dec 21, 2008 at 06:59:34PM +0800, Jaya Kumar wrote:
>> +static void broadsheetfb_dpy_update_pages(struct broadsheetfb_par *par,
>> +                                             u16 y1, u16 y2)
>> +{
>> +     u16 args[5];
>> +     unsigned char *buf = (unsigned char __force *)par->info->screen_base;
>
> You shouldn't add __force inside drivers.

Ok, will take that out.

>
>> +     videomemorysize = (DPY_W*DPY_H);
>> +     videomemory = vmalloc(videomemorysize);
>> +     if (!videomemory)
>> +             goto err_fb_rel;
>> +
>> +     memset(videomemory, 0, videomemorysize);
>> +
>> +     info->screen_base = (char __force __iomem *)videomemory;
>
> Ditto.

Ok, will take that out.

>
> Also, using vmalloc for the backing store means this memory can't be
> mmap()'d into userspace, which is a very common thing for framebuffer
> using programs to do.  If mmap() is to be denied, then you should
> provide a mmap implementation in the fb_ops structure.
>

I'm not sure I understand. broadsheetfb relies on defio to handle the
mmap and setup the fb_ops mmap handler. I'm using Xfbdev with this and
it works fine.

youtube clip of broadsheetfb with xeyes, xclock and rgbpaint here:
http://www.youtube.com/watch?v=ph48pWz2B3s

Thanks,
jaya

------------------------------------------------------------------------------

Re: [RFC 2.6.27 1/2] fbdev: add E-Ink Broadsheet controller support

[linux]

On Sun, Dec 21, 2008 at 06:12:04AM -0500, Jaya Kumar wrote:
> On Sun, Dec 21, 2008 at 6:06 AM,  <linux@arm.linux.org.uk> wrote:
> > Also, using vmalloc for the backing store means this memory can't be
> > mmap()'d into userspace, which is a very common thing for framebuffer
> > using programs to do.  If mmap() is to be denied, then you should
> > provide a mmap implementation in the fb_ops structure.
> >
> 
> I'm not sure I understand. broadsheetfb relies on defio to handle the
> mmap and setup the fb_ops mmap handler. I'm using Xfbdev with this and
> it works fine.

Ah, I see how it's working.  That's fine.

------------------------------------------------------------------------------

Re: [RFC 2.6.27 1/2] fbdev: add E-Ink Broadsheet controller support

[Magnus Damm]

Hi Jaya,

On Sun, Dec 21, 2008 at 7:59 PM, Jaya Kumar <jayakumar.lkml@gmail.com> wrote:
> This patch adds support for the E-Ink Broadsheet display controller

Looking good. While at the topic of deferred io I took the opportunity
to ask a bit about that below.

> +++ b/drivers/video/broadsheetfb.c

> +/*
> + * this is the slow path from userspace. they can seek and write to
> + * the fb. it's inefficient to do anything less than a full screen draw
> + */
> +static ssize_t broadsheetfb_write(struct fb_info *info, const char __user *buf,
> +                               size_t count, loff_t *ppos)
> +{
> +       struct broadsheetfb_par *par = info->par;
> +       unsigned long p = *ppos;
> +       void *dst;
> +       int err = 0;
> +       unsigned long total_size;
> +
> +       if (info->state != FBINFO_STATE_RUNNING)
> +               return -EPERM;
> +
> +       total_size = info->fix.smem_len;
> +
> +       if (p > total_size)
> +               return -EFBIG;
> +
> +       if (count > total_size) {
> +               err = -EFBIG;
> +               count = total_size;
> +       }
> +
> +       if (count + p > total_size) {
> +               if (!err)
> +                       err = -ENOSPC;
> +
> +               count = total_size - p;
> +       }
> +
> +       dst = (void __force *) (info->screen_base + p);
> +
> +       if (copy_from_user(dst, buf, count))
> +               err = -EFAULT;
> +
> +       if  (!err)
> +               *ppos += count;
> +
> +       broadsheetfb_dpy_update(par);
> +
> +       return (err) ? err : count;
> +}
> +
> +static struct fb_ops broadsheetfb_ops = {
> +       .owner          = THIS_MODULE,
> +       .fb_read        = fb_sys_read,
> +       .fb_write       = broadsheetfb_write,

I sort of expected to see fb_sys_write here. Same thing for
metronomefb. I wonder why you chose a custom write callback instead of
fb_sys_write. Maybe I need to do the same thing for sh_mobile_lcdcfb
and if so then we could hopefully share that code between our drivers.
=)

By using the xxx_dpy_update() function these drivers seem to force a
full screen update in their write() path. I'm not sure why though,
shouldn't the write() case should just let the fb_sync callback do the
sync for you? The fb_sys_write() function calls fb_sync _before_
writing though, I wonder why. Doesn't make sense to me - _after_
copying data sounds like a better place to flush. I don't know the
history of the code though, so there may be a good reason for this.

Also, this brings up to another interesting topic. While I was hacking
on deferred io for the sh_mobile_lcdcfb driver I realized that I
needed hooks to update the screen for the callbacks fb_fillarea,
fb_copyarea and fb_imageblit. The metronomefb driver and this one both
force a full screen update for each operation. In sh_mobile_lcdcfb I
chose to just schedule the delayed work instead. Either way is fine of
course, but this issue does not seem driver specific to me. So I
wonder if it is worth breaking out these sys-functions and handle all
that in fb_defio.c instead. But maybe we're just covering for the fact
that the fb console isn't syncing as it should?

Cheers,

/ magnus

------------------------------------------------------------------------------

Re: [RFC 2.6.27 1/2] fbdev: add E-Ink Broadsheet controller support

[Magnus Damm]

On Sun, Dec 21, 2008 at 11:58 PM, Magnus Damm <magnus.damm@gmail.com> wrote:
> Hi Jaya,
>
> On Sun, Dec 21, 2008 at 7:59 PM, Jaya Kumar <jayakumar.lkml@gmail.com> wrote:
>> This patch adds support for the E-Ink Broadsheet display controller
>
> Looking good. While at the topic of deferred io I took the opportunity
> to ask a bit about that below.
>
> I sort of expected to see fb_sys_write here. Same thing for
> metronomefb. I wonder why you chose a custom write callback instead of
> fb_sys_write. Maybe I need to do the same thing for sh_mobile_lcdcfb
> and if so then we could hopefully share that code between our drivers.
> =)
>
> By using the xxx_dpy_update() function these drivers seem to force a
> full screen update in their write() path. I'm not sure why though,
> shouldn't the write() case should just let the fb_sync callback do the
> sync for you? The fb_sys_write() function calls fb_sync _before_
> writing though, I wonder why. Doesn't make sense to me - _after_
> copying data sounds like a better place to flush. I don't know the
> history of the code though, so there may be a good reason for this.

Ok, I think I can answer that myself now:
The fb_sync() callback is used to synchronize hardware acceleration,
not to flush data. That's why it is syncing before the write
operation. My bad, I mixed fb_sync() up with the fsync() operation.

> Also, this brings up to another interesting topic. While I was hacking
> on deferred io for the sh_mobile_lcdcfb driver I realized that I
> needed hooks to update the screen for the callbacks fb_fillarea,
> fb_copyarea and fb_imageblit. The metronomefb driver and this one both
> force a full screen update for each operation. In sh_mobile_lcdcfb I
> chose to just schedule the delayed work instead. Either way is fine of
> course, but this issue does not seem driver specific to me. So I
> wonder if it is worth breaking out these sys-functions and handle all
> that in fb_defio.c instead. But maybe we're just covering for the fact
> that the fb console isn't syncing as it should?

I'm still not sure if it's a sane idea to modify the fb console so it
fsyncs. It's a separate issue I guess. Anyway, fsyncing data for each
accelerated operation sounds a bit slow to me, especially if that
triggers a full screen update. Think softcursor modifying a tiny part
of the screen and we redraw the entire screen. Otoh, console may not
be the biggest use case for deferred io. =)

I may hack up some shared some code later this week that triggers the
delayed work for sys_xxx operations - same type of delayed flushing as
my sh_mobile_lcdcfb driver. I plan on putting it in fb_defio.c and
letting it call the sys operations. Then the deferred io drivers can
install those callbacks into struct fb_ops directly. That way we can
remove similar code in 3 drivers at least. I'll begin with
sh_mobile_lcdcfb and we can do the other drivers one by one later on.

I'm not sure if you think it's a good idea. It's a bit different from
the direct fsyncing like you do today.

Thanks for your help!

/ magnus

------------------------------------------------------------------------------

Re: [RFC 2.6.27 1/2] fbdev: add E-Ink Broadsheet controller support

[Jaya Kumar]

On Sun, Dec 21, 2008 at 9:12 PM, Magnus Damm <magnus.damm@gmail.com> wrote:
> I'm still not sure if it's a sane idea to modify the fb console so it
> fsyncs. It's a separate issue I guess. Anyway, fsyncing data for each
> accelerated operation sounds a bit slow to me, especially if that
> triggers a full screen update. Think softcursor modifying a tiny part
> of the screen and we redraw the entire screen. Otoh, console may not
> be the biggest use case for deferred io. =)

Yes, you are correct that console isn't a good fit for e-ink displays
because drawing a flashing cursor will cause the whole screen to flash
every second (800ms is the minimum latency and yes, there's no partial
update capability on the metronome controller).

>
> I may hack up some shared some code later this week that triggers the
> delayed work for sys_xxx operations - same type of delayed flushing as
> my sh_mobile_lcdcfb driver. I plan on putting it in fb_defio.c and
> letting it call the sys operations. Then the deferred io drivers can
> install those callbacks into struct fb_ops directly. That way we can
> remove similar code in 3 drivers at least. I'll begin with
> sh_mobile_lcdcfb and we can do the other drivers one by one later on.
>
> I'm not sure if you think it's a good idea. It's a bit different from
> the direct fsyncing like you do today.
>

In general, your proposal sounds like a good idea to me. I'll take a
look at your patches now to understand if we're thinking the same
thing.

Thanks,
jaya

------------------------------------------------------------------------------

Re: [RFC 2.6.27 1/2] fbdev: add E-Ink Broadsheet controller support

[Russell King - ARM Linux]

On Sun, Dec 21, 2008 at 11:58:53PM +0900, Magnus Damm wrote:
> By using the <censored>_dpy_update() function these drivers seem to force a

Please don't use "ex ex ex" in email messages, it causes list admins
grief when they get lots of errors from stupidly setup domains such as:

    host asuka.sanyo.co.in [202.54.90.7]: 554 5.7.1 This message has been blocked because it contains a banned word.

Thank you.

------------------------------------------------------------------------------

Re: [RFC 2.6.27 1/2] fbdev: add E-Ink Broadsheet controller support

[Geert Uytterhoeven]

On Sun, 21 Dec 2008, Jaya Kumar wrote:
> --- /dev/null
> +++ b/drivers/video/broadsheetfb.c

> +static struct fb_var_screeninfo broadsheetfb_var __devinitdata = {
> +	.xres		= DPY_W,
> +	.yres		= DPY_H,
> +	.xres_virtual	= DPY_W,
> +	.yres_virtual	= DPY_H,
> +	.bits_per_pixel	= 8,
> +	.grayscale	= 1,
> +	.nonstd		= 1,

Why do you set .nonstd?

#define FB_NONSTD_HAM           1       /* Hold-And-Modify (HAM)        */

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds

------------------------------------------------------------------------------

Re: [RFC 2.6.27 1/2] fbdev: add E-Ink Broadsheet controller support

[Jaya Kumar]

On Tue, Dec 23, 2008 at 7:52 AM, Geert Uytterhoeven
<geert@linux-m68k.org> wrote:
> On Sun, 21 Dec 2008, Jaya Kumar wrote:
>> --- /dev/null
>> +++ b/drivers/video/broadsheetfb.c
>
>> +static struct fb_var_screeninfo broadsheetfb_var __devinitdata = {
>> +     .xres           = DPY_W,
>> +     .yres           = DPY_H,
>> +     .xres_virtual   = DPY_W,
>> +     .yres_virtual   = DPY_H,
>> +     .bits_per_pixel = 8,
>> +     .grayscale      = 1,
>> +     .nonstd         = 1,
>
> Why do you set .nonstd?
>
> #define FB_NONSTD_HAM           1       /* Hold-And-Modify (HAM)        */
>

Good point, shouldn't be set. Will take it out of broadsheetfb and
also the other e-ink drivers that set it.

Thanks,
jaya

------------------------------------------------------------------------------