drivers/video/omap2/vrfb.c - kernel/msm-4.9 - Gitiles

 /*
  * VRFB Rotation Engine
  *
  * Copyright (C) 2009 Nokia Corporation
  * Author: Tomi Valkeinen <tomi.valkeinen@nokia.com>
  *
  * 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.
  *
  * This program is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License along
  * with this program; if not, write to the Free Software Foundation, Inc.,
  * 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  */

 /*#define DEBUG*/

 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/ioport.h>
 #include <linux/io.h>
 #include <linux/bitops.h>
 #include <linux/mutex.h>
 #include <linux/platform_device.h>

 #include <video/omapvrfb.h>

 #ifdef DEBUG
 #define DBG(format, ...) pr_debug("VRFB: " format, ## __VA_ARGS__)
 #else
 #define DBG(format, ...)
 #endif

 #define SMS_ROT_CONTROL(context)	(0x0 + 0x10 * context)
 #define SMS_ROT_SIZE(context)		(0x4 + 0x10 * context)
 #define SMS_ROT_PHYSICAL_BA(context)	(0x8 + 0x10 * context)
 #define SMS_ROT_VIRT_BASE(rot)		(0x1000000 * (rot))

 #define OMAP_VRFB_SIZE			(2048 * 2048 * 4)

 #define VRFB_PAGE_WIDTH_EXP	5 /* Assuming SDRAM pagesize= 1024 */
 #define VRFB_PAGE_HEIGHT_EXP	5 /* 1024 = 2^5 * 2^5 */
 #define VRFB_PAGE_WIDTH		(1 << VRFB_PAGE_WIDTH_EXP)
 #define VRFB_PAGE_HEIGHT	(1 << VRFB_PAGE_HEIGHT_EXP)
 #define SMS_IMAGEHEIGHT_OFFSET	16
 #define SMS_IMAGEWIDTH_OFFSET	0
 #define SMS_PH_OFFSET		8
 #define SMS_PW_OFFSET		4
 #define SMS_PS_OFFSET		0

 /* bitmap of reserved contexts */
 static unsigned long ctx_map;

 struct vrfb_ctx {
 	u32 base;
 	u32 physical_ba;
 	u32 control;
 	u32 size;
 };

 static DEFINE_MUTEX(ctx_lock);

 /*
  * Access to this happens from client drivers or the PM core after wake-up.
  * For the first case we require locking at the driver level, for the second
  * we don't need locking, since no drivers will run until after the wake-up
  * has finished.
  */

 static void __iomem *vrfb_base;

 static int num_ctxs;
 static struct vrfb_ctx *ctxs;

 static bool vrfb_loaded;

 static void omap2_sms_write_rot_control(u32 val, unsigned ctx)
 {
 	__raw_writel(val, vrfb_base + SMS_ROT_CONTROL(ctx));
 }

 static void omap2_sms_write_rot_size(u32 val, unsigned ctx)
 {
 	__raw_writel(val, vrfb_base + SMS_ROT_SIZE(ctx));
 }

 static void omap2_sms_write_rot_physical_ba(u32 val, unsigned ctx)
 {
 	__raw_writel(val, vrfb_base + SMS_ROT_PHYSICAL_BA(ctx));
 }

 static inline void restore_hw_context(int ctx)
 {
 	omap2_sms_write_rot_control(ctxs[ctx].control, ctx);
 	omap2_sms_write_rot_size(ctxs[ctx].size, ctx);
 	omap2_sms_write_rot_physical_ba(ctxs[ctx].physical_ba, ctx);
 }

 static u32 get_image_width_roundup(u16 width, u8 bytespp)
 {
 	unsigned long stride = width * bytespp;
 	unsigned long ceil_pages_per_stride = (stride / VRFB_PAGE_WIDTH) +
 		(stride % VRFB_PAGE_WIDTH != 0);

 	return ceil_pages_per_stride * VRFB_PAGE_WIDTH / bytespp;
 }

 /*
  * This the extra space needed in the VRFB physical area for VRFB to safely wrap
  * any memory accesses to the invisible part of the virtual view to the physical
  * area.
  */
 static inline u32 get_extra_physical_size(u16 image_width_roundup, u8 bytespp)
 {
 	return (OMAP_VRFB_LINE_LEN - image_width_roundup) * VRFB_PAGE_HEIGHT *
 		bytespp;
 }

 void omap_vrfb_restore_context(void)
 {
 	int i;
 	unsigned long map = ctx_map;

 	for (i = ffs(map); i; i = ffs(map)) {
 		/* i=1..32 */
 		i--;
 		map &= ~(1 << i);
 		restore_hw_context(i);
 	}
 }

 void omap_vrfb_adjust_size(u16 *width, u16 *height,
 		u8 bytespp)
 {
 	*width = ALIGN(*width * bytespp, VRFB_PAGE_WIDTH) / bytespp;
 	*height = ALIGN(*height, VRFB_PAGE_HEIGHT);
 }
 EXPORT_SYMBOL(omap_vrfb_adjust_size);

 u32 omap_vrfb_min_phys_size(u16 width, u16 height, u8 bytespp)
 {
 	unsigned long image_width_roundup = get_image_width_roundup(width,
 		bytespp);

 	if (image_width_roundup > OMAP_VRFB_LINE_LEN)
 		return 0;

 	return (width * height * bytespp) + get_extra_physical_size(
 		image_width_roundup, bytespp);
 }
 EXPORT_SYMBOL(omap_vrfb_min_phys_size);

 u16 omap_vrfb_max_height(u32 phys_size, u16 width, u8 bytespp)
 {
 	unsigned long image_width_roundup = get_image_width_roundup(width,
 		bytespp);
 	unsigned long height;
 	unsigned long extra;

 	if (image_width_roundup > OMAP_VRFB_LINE_LEN)
 		return 0;

 	extra = get_extra_physical_size(image_width_roundup, bytespp);

 	if (phys_size < extra)
 		return 0;

 	height = (phys_size - extra) / (width * bytespp);

 	/* Virtual views provided by VRFB are limited to 2048x2048. */
 	return min_t(unsigned long, height, 2048);
 }
 EXPORT_SYMBOL(omap_vrfb_max_height);

 void omap_vrfb_setup(struct vrfb *vrfb, unsigned long paddr,
 		u16 width, u16 height,
 		unsigned bytespp, bool yuv_mode)
 {
 	unsigned pixel_size_exp;
 	u16 vrfb_width;
 	u16 vrfb_height;
 	u8 ctx = vrfb->context;
 	u32 size;
 	u32 control;

 	DBG("omapfb_set_vrfb(%d, %lx, %dx%d, %d, %d)\n", ctx, paddr,
 			width, height, bytespp, yuv_mode);

 	/* For YUV2 and UYVY modes VRFB needs to handle pixels a bit
 	 * differently. See TRM. */
 	if (yuv_mode) {
 		bytespp *= 2;
 		width /= 2;
 	}

 	if (bytespp == 4)
 		pixel_size_exp = 2;
 	else if (bytespp == 2)
 		pixel_size_exp = 1;
 	else {
 		BUG();
 		return;
 	}

 	vrfb_width = ALIGN(width * bytespp, VRFB_PAGE_WIDTH) / bytespp;
 	vrfb_height = ALIGN(height, VRFB_PAGE_HEIGHT);

 	DBG("vrfb w %u, h %u bytespp %d\n", vrfb_width, vrfb_height, bytespp);

 	size  = vrfb_width << SMS_IMAGEWIDTH_OFFSET;
 	size |= vrfb_height << SMS_IMAGEHEIGHT_OFFSET;

 	control  = pixel_size_exp << SMS_PS_OFFSET;
 	control |= VRFB_PAGE_WIDTH_EXP  << SMS_PW_OFFSET;
 	control |= VRFB_PAGE_HEIGHT_EXP << SMS_PH_OFFSET;

 	ctxs[ctx].physical_ba = paddr;
 	ctxs[ctx].size = size;
 	ctxs[ctx].control = control;

 	omap2_sms_write_rot_physical_ba(paddr, ctx);
 	omap2_sms_write_rot_size(size, ctx);
 	omap2_sms_write_rot_control(control, ctx);

 	DBG("vrfb offset pixels %d, %d\n",
 			vrfb_width - width, vrfb_height - height);

 	vrfb->xres = width;
 	vrfb->yres = height;
 	vrfb->xoffset = vrfb_width - width;
 	vrfb->yoffset = vrfb_height - height;
 	vrfb->bytespp = bytespp;
 	vrfb->yuv_mode = yuv_mode;
 }
 EXPORT_SYMBOL(omap_vrfb_setup);

 int omap_vrfb_map_angle(struct vrfb *vrfb, u16 height, u8 rot)
 {
 	unsigned long size = height * OMAP_VRFB_LINE_LEN * vrfb->bytespp;

 	vrfb->vaddr[rot] = ioremap_wc(vrfb->paddr[rot], size);

 	if (!vrfb->vaddr[rot]) {
 		printk(KERN_ERR "vrfb: ioremap failed\n");
 		return -ENOMEM;
 	}

 	DBG("ioremapped vrfb area %d of size %lu into %p\n", rot, size,
 		vrfb->vaddr[rot]);

 	return 0;
 }
 EXPORT_SYMBOL(omap_vrfb_map_angle);

 void omap_vrfb_release_ctx(struct vrfb *vrfb)
 {
 	int rot;
 	int ctx = vrfb->context;

 	if (ctx == 0xff)
 		return;

 	DBG("release ctx %d\n", ctx);

 	mutex_lock(&ctx_lock);

 	BUG_ON(!(ctx_map & (1 << ctx)));

 	clear_bit(ctx, &ctx_map);

 	for (rot = 0; rot < 4; ++rot) {
 		if (vrfb->paddr[rot]) {
 			release_mem_region(vrfb->paddr[rot], OMAP_VRFB_SIZE);
 			vrfb->paddr[rot] = 0;
 		}
 	}

 	vrfb->context = 0xff;

 	mutex_unlock(&ctx_lock);
 }
 EXPORT_SYMBOL(omap_vrfb_release_ctx);

 int omap_vrfb_request_ctx(struct vrfb *vrfb)
 {
 	int rot;
 	u32 paddr;
 	u8 ctx;
 	int r;

 	DBG("request ctx\n");

 	mutex_lock(&ctx_lock);

 	for (ctx = 0; ctx < num_ctxs; ++ctx)
 		if ((ctx_map & (1 << ctx)) == 0)
 			break;

 	if (ctx == num_ctxs) {
 		pr_err("vrfb: no free contexts\n");
 		r = -EBUSY;
 		goto out;
 	}

 	DBG("found free ctx %d\n", ctx);

 	set_bit(ctx, &ctx_map);

 	memset(vrfb, 0, sizeof(*vrfb));

 	vrfb->context = ctx;

 	for (rot = 0; rot < 4; ++rot) {
 		paddr = ctxs[ctx].base + SMS_ROT_VIRT_BASE(rot);
 		if (!request_mem_region(paddr, OMAP_VRFB_SIZE, "vrfb")) {
 			pr_err("vrfb: failed to reserve VRFB "
 					"area for ctx %d, rotation %d\n",
 					ctx, rot * 90);
 			omap_vrfb_release_ctx(vrfb);
 			r = -ENOMEM;
 			goto out;
 		}

 		vrfb->paddr[rot] = paddr;

 		DBG("VRFB %d/%d: %lx\n", ctx, rot*90, vrfb->paddr[rot]);
 	}

 	r = 0;
 out:
 	mutex_unlock(&ctx_lock);
 	return r;
 }
 EXPORT_SYMBOL(omap_vrfb_request_ctx);

 bool omap_vrfb_supported(void)
 {
 	return vrfb_loaded;
 }
 EXPORT_SYMBOL(omap_vrfb_supported);

 static int __init vrfb_probe(struct platform_device *pdev)
 {
 	struct resource *mem;
 	int i;

 	/* first resource is the register res, the rest are vrfb contexts */

 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!mem) {
 		dev_err(&pdev->dev, "can't get vrfb base address\n");
 		return -EINVAL;
 	}

 	vrfb_base = devm_request_and_ioremap(&pdev->dev, mem);
 	if (!vrfb_base) {
 		dev_err(&pdev->dev, "can't ioremap vrfb memory\n");
 		return -ENOMEM;
 	}

 	num_ctxs = pdev->num_resources - 1;

 	ctxs = devm_kzalloc(&pdev->dev,
 			sizeof(struct vrfb_ctx) * num_ctxs,
 			GFP_KERNEL);

 	if (!ctxs)
 		return -ENOMEM;

 	for (i = 0; i < num_ctxs; ++i) {
 		mem = platform_get_resource(pdev, IORESOURCE_MEM, 1 + i);
 		if (!mem) {
 			dev_err(&pdev->dev, "can't get vrfb ctx %d address\n",
 					i);
 			return -EINVAL;
 		}

 		ctxs[i].base = mem->start;
 	}

 	vrfb_loaded = true;

 	return 0;
 }

 static void __exit vrfb_remove(struct platform_device *pdev)
 {
 	vrfb_loaded = false;
 }

 static struct platform_driver vrfb_driver = {
 	.driver.name	= "omapvrfb",
 	.remove		= __exit_p(vrfb_remove),
 };

 static int __init vrfb_init(void)
 {
 	return platform_driver_probe(&vrfb_driver, &vrfb_probe);
 }

 static void __exit vrfb_exit(void)
 {
 	platform_driver_unregister(&vrfb_driver);
 }

 module_init(vrfb_init);
 module_exit(vrfb_exit);

 MODULE_AUTHOR("Tomi Valkeinen <tomi.valkeinen@ti.com>");
 MODULE_DESCRIPTION("OMAP VRFB");
 MODULE_LICENSE("GPL v2");
	/*
	* VRFB Rotation Engine
	*
	* Copyright (C) 2009 Nokia Corporation
	* Author: Tomi Valkeinen <tomi.valkeinen@nokia.com>
	*
	* 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.
	*
	* This program is distributed in the hope that it will be useful, but
	* WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License along
	* with this program; if not, write to the Free Software Foundation, Inc.,
	* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	*/

	/#define DEBUG/

	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/ioport.h>
	#include <linux/io.h>
	#include <linux/bitops.h>
	#include <linux/mutex.h>
	#include <linux/platform_device.h>

	#include <video/omapvrfb.h>

	#ifdef DEBUG
	#define DBG(format, ...) pr_debug("VRFB: " format, ## __VA_ARGS__)
	#else
	#define DBG(format, ...)
	#endif

	#define SMS_ROT_CONTROL(context) (0x0 + 0x10 * context)
	#define SMS_ROT_SIZE(context) (0x4 + 0x10 * context)
	#define SMS_ROT_PHYSICAL_BA(context) (0x8 + 0x10 * context)
	#define SMS_ROT_VIRT_BASE(rot) (0x1000000 * (rot))

	#define OMAP_VRFB_SIZE (2048 * 2048 * 4)

	#define VRFB_PAGE_WIDTH_EXP 5 /* Assuming SDRAM pagesize= 1024 */
	#define VRFB_PAGE_HEIGHT_EXP 5 /* 1024 = 2^5 * 2^5 */
	#define VRFB_PAGE_WIDTH (1 << VRFB_PAGE_WIDTH_EXP)
	#define VRFB_PAGE_HEIGHT (1 << VRFB_PAGE_HEIGHT_EXP)
	#define SMS_IMAGEHEIGHT_OFFSET 16
	#define SMS_IMAGEWIDTH_OFFSET 0
	#define SMS_PH_OFFSET 8
	#define SMS_PW_OFFSET 4
	#define SMS_PS_OFFSET 0

	/* bitmap of reserved contexts */
	static unsigned long ctx_map;

	struct vrfb_ctx {
	u32 base;
	u32 physical_ba;
	u32 control;
	u32 size;
	};

	static DEFINE_MUTEX(ctx_lock);

	/*
	* Access to this happens from client drivers or the PM core after wake-up.
	* For the first case we require locking at the driver level, for the second
	* we don't need locking, since no drivers will run until after the wake-up
	* has finished.
	*/

	static void __iomem *vrfb_base;

	static int num_ctxs;
	static struct vrfb_ctx *ctxs;

	static bool vrfb_loaded;

	static void omap2_sms_write_rot_control(u32 val, unsigned ctx)
	{
	__raw_writel(val, vrfb_base + SMS_ROT_CONTROL(ctx));
	}

	static void omap2_sms_write_rot_size(u32 val, unsigned ctx)
	{
	__raw_writel(val, vrfb_base + SMS_ROT_SIZE(ctx));
	}

	static void omap2_sms_write_rot_physical_ba(u32 val, unsigned ctx)
	{
	__raw_writel(val, vrfb_base + SMS_ROT_PHYSICAL_BA(ctx));
	}

	static inline void restore_hw_context(int ctx)
	{
	omap2_sms_write_rot_control(ctxs[ctx].control, ctx);
	omap2_sms_write_rot_size(ctxs[ctx].size, ctx);
	omap2_sms_write_rot_physical_ba(ctxs[ctx].physical_ba, ctx);
	}

	static u32 get_image_width_roundup(u16 width, u8 bytespp)
	{
	unsigned long stride = width * bytespp;
	unsigned long ceil_pages_per_stride = (stride / VRFB_PAGE_WIDTH) +
	(stride % VRFB_PAGE_WIDTH != 0);

	return ceil_pages_per_stride * VRFB_PAGE_WIDTH / bytespp;
	}

	/*
	* This the extra space needed in the VRFB physical area for VRFB to safely wrap
	* any memory accesses to the invisible part of the virtual view to the physical
	* area.
	*/
	static inline u32 get_extra_physical_size(u16 image_width_roundup, u8 bytespp)
	{
	return (OMAP_VRFB_LINE_LEN - image_width_roundup) * VRFB_PAGE_HEIGHT *
	bytespp;
	}

	void omap_vrfb_restore_context(void)
	{
	int i;
	unsigned long map = ctx_map;

	for (i = ffs(map); i; i = ffs(map)) {
	/* i=1..32 */
	i--;
	map &= ~(1 << i);
	restore_hw_context(i);
	}
	}

	void omap_vrfb_adjust_size(u16 width, u16 height,
	u8 bytespp)
	{
	width = ALIGN(width * bytespp, VRFB_PAGE_WIDTH) / bytespp;
	height = ALIGN(height, VRFB_PAGE_HEIGHT);
	}
	EXPORT_SYMBOL(omap_vrfb_adjust_size);

	u32 omap_vrfb_min_phys_size(u16 width, u16 height, u8 bytespp)
	{
	unsigned long image_width_roundup = get_image_width_roundup(width,
	bytespp);

	if (image_width_roundup > OMAP_VRFB_LINE_LEN)
	return 0;

	return (width * height * bytespp) + get_extra_physical_size(
	image_width_roundup, bytespp);
	}
	EXPORT_SYMBOL(omap_vrfb_min_phys_size);

	u16 omap_vrfb_max_height(u32 phys_size, u16 width, u8 bytespp)
	{
	unsigned long image_width_roundup = get_image_width_roundup(width,
	bytespp);
	unsigned long height;
	unsigned long extra;

	if (image_width_roundup > OMAP_VRFB_LINE_LEN)
	return 0;

	extra = get_extra_physical_size(image_width_roundup, bytespp);

	if (phys_size < extra)
	return 0;

	height = (phys_size - extra) / (width * bytespp);

	/* Virtual views provided by VRFB are limited to 2048x2048. */
	return min_t(unsigned long, height, 2048);
	}
	EXPORT_SYMBOL(omap_vrfb_max_height);

	void omap_vrfb_setup(struct vrfb *vrfb, unsigned long paddr,
	u16 width, u16 height,
	unsigned bytespp, bool yuv_mode)
	{
	unsigned pixel_size_exp;
	u16 vrfb_width;
	u16 vrfb_height;
	u8 ctx = vrfb->context;
	u32 size;
	u32 control;

	DBG("omapfb_set_vrfb(%d, %lx, %dx%d, %d, %d)\n", ctx, paddr,
	width, height, bytespp, yuv_mode);

	/* For YUV2 and UYVY modes VRFB needs to handle pixels a bit
	* differently. See TRM. */
	if (yuv_mode) {
	bytespp *= 2;
	width /= 2;
	}

	if (bytespp == 4)
	pixel_size_exp = 2;
	else if (bytespp == 2)
	pixel_size_exp = 1;
	else {
	BUG();
	return;
	}

	vrfb_width = ALIGN(width * bytespp, VRFB_PAGE_WIDTH) / bytespp;
	vrfb_height = ALIGN(height, VRFB_PAGE_HEIGHT);

	DBG("vrfb w %u, h %u bytespp %d\n", vrfb_width, vrfb_height, bytespp);

	size = vrfb_width << SMS_IMAGEWIDTH_OFFSET;
	size \|= vrfb_height << SMS_IMAGEHEIGHT_OFFSET;

	control = pixel_size_exp << SMS_PS_OFFSET;
	control \|= VRFB_PAGE_WIDTH_EXP << SMS_PW_OFFSET;
	control \|= VRFB_PAGE_HEIGHT_EXP << SMS_PH_OFFSET;

	ctxs[ctx].physical_ba = paddr;
	ctxs[ctx].size = size;
	ctxs[ctx].control = control;

	omap2_sms_write_rot_physical_ba(paddr, ctx);
	omap2_sms_write_rot_size(size, ctx);
	omap2_sms_write_rot_control(control, ctx);

	DBG("vrfb offset pixels %d, %d\n",
	vrfb_width - width, vrfb_height - height);

	vrfb->xres = width;
	vrfb->yres = height;
	vrfb->xoffset = vrfb_width - width;
	vrfb->yoffset = vrfb_height - height;
	vrfb->bytespp = bytespp;
	vrfb->yuv_mode = yuv_mode;
	}
	EXPORT_SYMBOL(omap_vrfb_setup);

	int omap_vrfb_map_angle(struct vrfb *vrfb, u16 height, u8 rot)
	{
	unsigned long size = height * OMAP_VRFB_LINE_LEN * vrfb->bytespp;

	vrfb->vaddr[rot] = ioremap_wc(vrfb->paddr[rot], size);

	if (!vrfb->vaddr[rot]) {
	printk(KERN_ERR "vrfb: ioremap failed\n");
	return -ENOMEM;
	}

	DBG("ioremapped vrfb area %d of size %lu into %p\n", rot, size,
	vrfb->vaddr[rot]);

	return 0;
	}
	EXPORT_SYMBOL(omap_vrfb_map_angle);

	void omap_vrfb_release_ctx(struct vrfb *vrfb)
	{
	int rot;
	int ctx = vrfb->context;

	if (ctx == 0xff)
	return;

	DBG("release ctx %d\n", ctx);

	mutex_lock(&ctx_lock);

	BUG_ON(!(ctx_map & (1 << ctx)));

	clear_bit(ctx, &ctx_map);

	for (rot = 0; rot < 4; ++rot) {
	if (vrfb->paddr[rot]) {
	release_mem_region(vrfb->paddr[rot], OMAP_VRFB_SIZE);
	vrfb->paddr[rot] = 0;
	}
	}

	vrfb->context = 0xff;

	mutex_unlock(&ctx_lock);
	}
	EXPORT_SYMBOL(omap_vrfb_release_ctx);

	int omap_vrfb_request_ctx(struct vrfb *vrfb)
	{
	int rot;
	u32 paddr;
	u8 ctx;
	int r;

	DBG("request ctx\n");

	mutex_lock(&ctx_lock);

	for (ctx = 0; ctx < num_ctxs; ++ctx)
	if ((ctx_map & (1 << ctx)) == 0)
	break;

	if (ctx == num_ctxs) {
	pr_err("vrfb: no free contexts\n");
	r = -EBUSY;
	goto out;
	}

	DBG("found free ctx %d\n", ctx);

	set_bit(ctx, &ctx_map);

	memset(vrfb, 0, sizeof(*vrfb));

	vrfb->context = ctx;

	for (rot = 0; rot < 4; ++rot) {
	paddr = ctxs[ctx].base + SMS_ROT_VIRT_BASE(rot);
	if (!request_mem_region(paddr, OMAP_VRFB_SIZE, "vrfb")) {
	pr_err("vrfb: failed to reserve VRFB "
	"area for ctx %d, rotation %d\n",
	ctx, rot * 90);
	omap_vrfb_release_ctx(vrfb);
	r = -ENOMEM;
	goto out;
	}

	vrfb->paddr[rot] = paddr;

	DBG("VRFB %d/%d: %lx\n", ctx, rot*90, vrfb->paddr[rot]);
	}

	r = 0;
	out:
	mutex_unlock(&ctx_lock);
	return r;
	}
	EXPORT_SYMBOL(omap_vrfb_request_ctx);

	bool omap_vrfb_supported(void)
	{
	return vrfb_loaded;
	}
	EXPORT_SYMBOL(omap_vrfb_supported);

	static int __init vrfb_probe(struct platform_device *pdev)
	{
	struct resource *mem;
	int i;

	/* first resource is the register res, the rest are vrfb contexts */

	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!mem) {
	dev_err(&pdev->dev, "can't get vrfb base address\n");
	return -EINVAL;
	}

	vrfb_base = devm_request_and_ioremap(&pdev->dev, mem);
	if (!vrfb_base) {
	dev_err(&pdev->dev, "can't ioremap vrfb memory\n");
	return -ENOMEM;
	}

	num_ctxs = pdev->num_resources - 1;

	ctxs = devm_kzalloc(&pdev->dev,
	sizeof(struct vrfb_ctx) * num_ctxs,
	GFP_KERNEL);

	if (!ctxs)
	return -ENOMEM;

	for (i = 0; i < num_ctxs; ++i) {
	mem = platform_get_resource(pdev, IORESOURCE_MEM, 1 + i);
	if (!mem) {
	dev_err(&pdev->dev, "can't get vrfb ctx %d address\n",
	i);
	return -EINVAL;
	}

	ctxs[i].base = mem->start;
	}

	vrfb_loaded = true;

	return 0;
	}

	static void __exit vrfb_remove(struct platform_device *pdev)
	{
	vrfb_loaded = false;
	}

	static struct platform_driver vrfb_driver = {
	.driver.name = "omapvrfb",
	.remove = __exit_p(vrfb_remove),
	};

	static int __init vrfb_init(void)
	{
	return platform_driver_probe(&vrfb_driver, &vrfb_probe);
	}

	static void __exit vrfb_exit(void)
	{
	platform_driver_unregister(&vrfb_driver);
	}

	module_init(vrfb_init);
	module_exit(vrfb_exit);

	MODULE_AUTHOR("Tomi Valkeinen <tomi.valkeinen@ti.com>");
	MODULE_DESCRIPTION("OMAP VRFB");
	MODULE_LICENSE("GPL v2");