drivers/video/fbdev/goldfishfb.c - kernel/common.git - Git at Google

 /*
  * Copyright (C) 2007 Google, Inc.
  * Copyright (C) 2012 Intel, Inc.
  *
  * This software is licensed under the terms of the GNU General Public
  * License version 2, as published by the Free Software Foundation, and
  * may be copied, distributed, and modified under those terms.
  *
  * 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.
  *
  */

 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/dma-mapping.h>
 #include <linux/errno.h>
 #include <linux/string.h>
 #include <linux/slab.h>
 #include <linux/delay.h>
 #include <linux/mm.h>
 #include <linux/fb.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/ioport.h>
 #include <linux/platform_device.h>
 #include <linux/acpi.h>

 enum {
 	FB_GET_WIDTH        = 0x00,
 	FB_GET_HEIGHT       = 0x04,
 	FB_INT_STATUS       = 0x08,
 	FB_INT_ENABLE       = 0x0c,
 	FB_SET_BASE         = 0x10,
 	FB_SET_ROTATION     = 0x14,
 	FB_SET_BLANK        = 0x18,
 	FB_GET_PHYS_WIDTH   = 0x1c,
 	FB_GET_PHYS_HEIGHT  = 0x20,
 	FB_GET_FORMAT       = 0x24,

 	FB_INT_VSYNC             = 1U << 0,
 	FB_INT_BASE_UPDATE_DONE  = 1U << 1
 };

 /* These values *must* match the platform definitions found under
  * <system/graphics.h>
  */
 enum {
 	HAL_PIXEL_FORMAT_RGBA_8888          = 1,
 	HAL_PIXEL_FORMAT_RGBX_8888          = 2,
 	HAL_PIXEL_FORMAT_RGB_888            = 3,
 	HAL_PIXEL_FORMAT_RGB_565            = 4,
 	HAL_PIXEL_FORMAT_BGRA_8888          = 5,
 };

 struct framebuffer_config {
 	u8 bytes_per_pixel;
 	u8 red_offset;
 	u8 red_length;
 	u8 green_offset;
 	u8 green_length;
 	u8 blue_offset;
 	u8 blue_length;
 	u8 transp_offset;
 	u8 transp_length;
 };

 enum {
 	CHAR_BIT = 8
 };

 static const struct framebuffer_config *get_fb_config_from_format(int format)
 {
 	static const struct framebuffer_config fb_configs[] = {
 		{ 0, 0,  0, 0, 0, 0,  0, 0,  0 }, /* Invalid, assume RGB_565 */
 		{ 4, 0,  8, 8, 8, 16, 8, 24, 8 }, /* HAL_PIXEL_FORMAT_RGBA_8888 */
 		{ 4, 0,  8, 8, 8, 16, 8, 0,  0 }, /* HAL_PIXEL_FORMAT_RGBX_8888 */
 		{ 3, 0,  8, 8, 8, 16, 8, 0,  0 }, /* HAL_PIXEL_FORMAT_RGB_888 */
 		{ 2, 11, 5, 5, 6, 0,  5, 0,  0 }, /* HAL_PIXEL_FORMAT_RGB_565 */
 		{ 4, 16, 8, 8, 8, 0,  8, 24, 8 }, /* HAL_PIXEL_FORMAT_BGRA_8888 */
 	};

 	if (format > 0 &&
 		format < sizeof(fb_configs) / sizeof(struct framebuffer_config)) {
 		return &fb_configs[format];
 	}

 	return &fb_configs[HAL_PIXEL_FORMAT_RGB_565]; /* legacy default */
 }

 struct goldfish_fb {
 	void __iomem *reg_base;
 	int irq;
 	spinlock_t lock;
 	wait_queue_head_t wait;
 	int base_update_count;
 	int rotation;
 	struct fb_info fb;
 	u32 cmap[16];
 };

 static irqreturn_t goldfish_fb_interrupt(int irq, void *dev_id)
 {
 	unsigned long irq_flags;
 	struct goldfish_fb *fb = dev_id;
 	u32 status;

 	spin_lock_irqsave(&fb->lock, irq_flags);
 	status = readl(fb->reg_base + FB_INT_STATUS);
 	if (status & FB_INT_BASE_UPDATE_DONE) {
 		fb->base_update_count++;
 		wake_up(&fb->wait);
 	}
 	spin_unlock_irqrestore(&fb->lock, irq_flags);
 	return status ? IRQ_HANDLED : IRQ_NONE;
 }

 static inline u32 convert_bitfield(int val, struct fb_bitfield *bf)
 {
 	unsigned int mask = (1 << bf->length) - 1;

 	return (val >> (16 - bf->length) & mask) << bf->offset;
 }

 static int
 goldfish_fb_setcolreg(unsigned int regno, unsigned int red, unsigned int green,
 		 unsigned int blue, unsigned int transp, struct fb_info *info)
 {
 	struct goldfish_fb *fb = container_of(info, struct goldfish_fb, fb);

 	if (regno < 16) {
 		fb->cmap[regno] = convert_bitfield(transp, &fb->fb.var.transp) |
 				  convert_bitfield(blue, &fb->fb.var.blue) |
 				  convert_bitfield(green, &fb->fb.var.green) |
 				  convert_bitfield(red, &fb->fb.var.red);
 		return 0;
 	} else {
 		return 1;
 	}
 }

 static int goldfish_fb_check_var(struct fb_var_screeninfo *var,
 							struct fb_info *info)
 {
 	if ((var->rotate & 1) != (info->var.rotate & 1)) {
 		if ((var->xres != info->var.yres) ||
 				(var->yres != info->var.xres) ||
 				(var->xres_virtual != info->var.yres) ||
 				(var->yres_virtual > info->var.xres * 2) ||
 				(var->yres_virtual < info->var.xres)) {
 			return -EINVAL;
 		}
 	} else {
 		if ((var->xres != info->var.xres) ||
 		   (var->yres != info->var.yres) ||
 		   (var->xres_virtual != info->var.xres) ||
 		   (var->yres_virtual > info->var.yres * 2) ||
 		   (var->yres_virtual < info->var.yres)) {
 			return -EINVAL;
 		}
 	}
 	if ((var->xoffset != info->var.xoffset) ||
 			(var->bits_per_pixel != info->var.bits_per_pixel) ||
 			(var->grayscale != info->var.grayscale)) {
 		return -EINVAL;
 	}
 	return 0;
 }

 static int goldfish_fb_set_par(struct fb_info *info)
 {
 	struct goldfish_fb *fb = container_of(info, struct goldfish_fb, fb);

 	if (fb->rotation != fb->fb.var.rotate) {
 		info->fix.line_length = info->var.xres *
 			(fb->fb.var.bits_per_pixel / CHAR_BIT);
 		fb->rotation = fb->fb.var.rotate;
 		writel(fb->rotation, fb->reg_base + FB_SET_ROTATION);
 	}
 	return 0;
 }


 static int goldfish_fb_pan_display(struct fb_var_screeninfo *var,
 							struct fb_info *info)
 {
 	unsigned long irq_flags;
 	int base_update_count;
 	struct goldfish_fb *fb = container_of(info, struct goldfish_fb, fb);

 	spin_lock_irqsave(&fb->lock, irq_flags);
 	base_update_count = fb->base_update_count;
 	writel(fb->fb.fix.smem_start +
 			fb->fb.var.xres *
 			(fb->fb.var.bits_per_pixel / CHAR_BIT) *
 			var->yoffset,
 			fb->reg_base + FB_SET_BASE);
 	spin_unlock_irqrestore(&fb->lock, irq_flags);
 	wait_event_timeout(fb->wait,
 			fb->base_update_count != base_update_count, HZ / 15);
 	if (fb->base_update_count == base_update_count)
 		pr_err("goldfish_fb_pan_display: timeout waiting for "
 			"base update\n");
 	return 0;
 }

 static int goldfish_fb_blank(int blank, struct fb_info *info)
 {
 	struct goldfish_fb *fb = container_of(info, struct goldfish_fb, fb);

 	switch (blank) {
 	case FB_BLANK_NORMAL:
 		writel(1, fb->reg_base + FB_SET_BLANK);
 		break;
 	case FB_BLANK_UNBLANK:
 		writel(0, fb->reg_base + FB_SET_BLANK);
 		break;
 	}
 	return 0;
 }

 static struct fb_ops goldfish_fb_ops = {
 	.owner          = THIS_MODULE,
 	.fb_check_var   = goldfish_fb_check_var,
 	.fb_set_par     = goldfish_fb_set_par,
 	.fb_setcolreg   = goldfish_fb_setcolreg,
 	.fb_pan_display = goldfish_fb_pan_display,
 	.fb_blank	= goldfish_fb_blank,
 	.fb_fillrect    = cfb_fillrect,
 	.fb_copyarea    = cfb_copyarea,
 	.fb_imageblit   = cfb_imageblit,
 };


 static int goldfish_fb_probe(struct platform_device *pdev)
 {
 	int ret;
 	struct resource *r;
 	struct goldfish_fb *fb;
 	size_t framesize;
 	u32 width, height, format;
 	int bytes_per_pixel;
 	dma_addr_t fbpaddr;
 	const struct framebuffer_config *fb_config;

 	fb = kzalloc(sizeof(*fb), GFP_KERNEL);
 	if (fb == NULL) {
 		ret = -ENOMEM;
 		goto err_fb_alloc_failed;
 	}
 	spin_lock_init(&fb->lock);
 	init_waitqueue_head(&fb->wait);
 	platform_set_drvdata(pdev, fb);

 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (r == NULL) {
 		ret = -ENODEV;
 		goto err_no_io_base;
 	}
 	fb->reg_base = ioremap(r->start, PAGE_SIZE);
 	if (fb->reg_base == NULL) {
 		ret = -ENOMEM;
 		goto err_no_io_base;
 	}

 	fb->irq = platform_get_irq(pdev, 0);
 	if (fb->irq <= 0) {
 		ret = -ENODEV;
 		goto err_no_irq;
 	}

 	width = readl(fb->reg_base + FB_GET_WIDTH);
 	height = readl(fb->reg_base + FB_GET_HEIGHT);
 	format = readl(fb->reg_base + FB_GET_FORMAT);
 	fb_config = get_fb_config_from_format(format);
 	if (!fb_config) {
 		ret = -EINVAL;
 		goto err_no_irq;
 	}
 	bytes_per_pixel = fb_config->bytes_per_pixel;

 	fb->fb.fbops		= &goldfish_fb_ops;
 	fb->fb.flags		= FBINFO_FLAG_DEFAULT;
 	fb->fb.pseudo_palette	= fb->cmap;
 	fb->fb.fix.type		= FB_TYPE_PACKED_PIXELS;
 	fb->fb.fix.visual = FB_VISUAL_TRUECOLOR;
 	fb->fb.fix.line_length = width * bytes_per_pixel;
 	fb->fb.fix.accel	= FB_ACCEL_NONE;
 	fb->fb.fix.ypanstep = 1;

 	fb->fb.var.xres		= width;
 	fb->fb.var.yres		= height;
 	fb->fb.var.xres_virtual	= width;
 	fb->fb.var.yres_virtual	= height * 2;
 	fb->fb.var.bits_per_pixel = bytes_per_pixel * CHAR_BIT;
 	fb->fb.var.activate	= FB_ACTIVATE_NOW;
 	fb->fb.var.height	= readl(fb->reg_base + FB_GET_PHYS_HEIGHT);
 	fb->fb.var.width	= readl(fb->reg_base + FB_GET_PHYS_WIDTH);
 	fb->fb.var.pixclock	= 0;

 	fb->fb.var.red.offset = fb_config->red_offset;
 	fb->fb.var.red.length = fb_config->red_length;
 	fb->fb.var.green.offset = fb_config->green_offset;
 	fb->fb.var.green.length = fb_config->green_length;
 	fb->fb.var.blue.offset = fb_config->blue_offset;
 	fb->fb.var.blue.length = fb_config->blue_length;
 	fb->fb.var.transp.offset = fb_config->transp_offset;
 	fb->fb.var.transp.length = fb_config->transp_length;

 	framesize = width * height * 2 * bytes_per_pixel;
 	fb->fb.screen_base = (char __force __iomem *)dma_alloc_coherent(
 						&pdev->dev, framesize,
 						&fbpaddr, GFP_KERNEL);
 	pr_debug("allocating frame buffer %d * %d, got %p\n",
 					width, height, fb->fb.screen_base);
 	if (fb->fb.screen_base == NULL) {
 		ret = -ENOMEM;
 		goto err_alloc_screen_base_failed;
 	}
 	fb->fb.fix.smem_start = fbpaddr;
 	fb->fb.fix.smem_len = framesize;

 	ret = fb_set_var(&fb->fb, &fb->fb.var);
 	if (ret)
 		goto err_fb_set_var_failed;

 	ret = request_irq(fb->irq, goldfish_fb_interrupt, IRQF_SHARED,
 							pdev->name, fb);
 	if (ret)
 		goto err_request_irq_failed;

 	writel(FB_INT_BASE_UPDATE_DONE, fb->reg_base + FB_INT_ENABLE);
 	goldfish_fb_pan_display(&fb->fb.var, &fb->fb); /* updates base */

 	ret = register_framebuffer(&fb->fb);
 	if (ret)
 		goto err_register_framebuffer_failed;
 	return 0;

 err_register_framebuffer_failed:
 	free_irq(fb->irq, fb);
 err_request_irq_failed:
 err_fb_set_var_failed:
 	dma_free_coherent(&pdev->dev, framesize,
 				(void *)fb->fb.screen_base,
 				fb->fb.fix.smem_start);
 err_alloc_screen_base_failed:
 err_no_irq:
 	iounmap(fb->reg_base);
 err_no_io_base:
 	kfree(fb);
 err_fb_alloc_failed:
 	return ret;
 }

 static int goldfish_fb_remove(struct platform_device *pdev)
 {
 	size_t framesize;
 	struct goldfish_fb *fb = platform_get_drvdata(pdev);

 	framesize = fb->fb.var.xres_virtual * fb->fb.var.yres_virtual *
 		(fb->fb.var.bits_per_pixel / CHAR_BIT);
 	unregister_framebuffer(&fb->fb);
 	free_irq(fb->irq, fb);

 	dma_free_coherent(&pdev->dev, framesize, (void *)fb->fb.screen_base,
 						fb->fb.fix.smem_start);
 	iounmap(fb->reg_base);
 	kfree(fb);
 	return 0;
 }

 static const struct of_device_id goldfish_fb_of_match[] = {
 	{ .compatible = "google,goldfish-fb", },
 	{},
 };
 MODULE_DEVICE_TABLE(of, goldfish_fb_of_match);

 static const struct acpi_device_id goldfish_fb_acpi_match[] = {
 	{ "GFSH0004", 0 },
 	{ },
 };
 MODULE_DEVICE_TABLE(acpi, goldfish_fb_acpi_match);

 static struct platform_driver goldfish_fb_driver = {
 	.probe		= goldfish_fb_probe,
 	.remove		= goldfish_fb_remove,
 	.driver = {
 		.name = "goldfish_fb",
 		.of_match_table = goldfish_fb_of_match,
 		.acpi_match_table = ACPI_PTR(goldfish_fb_acpi_match),
 	}
 };

 module_platform_driver(goldfish_fb_driver);

 MODULE_LICENSE("GPL v2");
	/*
	* Copyright (C) 2007 Google, Inc.
	* Copyright (C) 2012 Intel, Inc.
	*
	* This software is licensed under the terms of the GNU General Public
	* License version 2, as published by the Free Software Foundation, and
	* may be copied, distributed, and modified under those terms.
	*
	* 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.
	*
	*/

	#include <linux/module.h>
	#include <linux/kernel.h>
	#include <linux/dma-mapping.h>
	#include <linux/errno.h>
	#include <linux/string.h>
	#include <linux/slab.h>
	#include <linux/delay.h>
	#include <linux/mm.h>
	#include <linux/fb.h>
	#include <linux/init.h>
	#include <linux/interrupt.h>
	#include <linux/ioport.h>
	#include <linux/platform_device.h>
	#include <linux/acpi.h>

	enum {
	FB_GET_WIDTH = 0x00,
	FB_GET_HEIGHT = 0x04,
	FB_INT_STATUS = 0x08,
	FB_INT_ENABLE = 0x0c,
	FB_SET_BASE = 0x10,
	FB_SET_ROTATION = 0x14,
	FB_SET_BLANK = 0x18,
	FB_GET_PHYS_WIDTH = 0x1c,
	FB_GET_PHYS_HEIGHT = 0x20,
	FB_GET_FORMAT = 0x24,

	FB_INT_VSYNC = 1U << 0,
	FB_INT_BASE_UPDATE_DONE = 1U << 1
	};

	/* These values must match the platform definitions found under
	* <system/graphics.h>
	*/
	enum {
	HAL_PIXEL_FORMAT_RGBA_8888 = 1,
	HAL_PIXEL_FORMAT_RGBX_8888 = 2,
	HAL_PIXEL_FORMAT_RGB_888 = 3,
	HAL_PIXEL_FORMAT_RGB_565 = 4,
	HAL_PIXEL_FORMAT_BGRA_8888 = 5,
	};

	struct framebuffer_config {
	u8 bytes_per_pixel;
	u8 red_offset;
	u8 red_length;
	u8 green_offset;
	u8 green_length;
	u8 blue_offset;
	u8 blue_length;
	u8 transp_offset;
	u8 transp_length;
	};

	enum {
	CHAR_BIT = 8
	};

	static const struct framebuffer_config *get_fb_config_from_format(int format)
	{
	static const struct framebuffer_config fb_configs[] = {
	{ 0, 0, 0, 0, 0, 0, 0, 0, 0 }, /* Invalid, assume RGB_565 */
	{ 4, 0, 8, 8, 8, 16, 8, 24, 8 }, /* HAL_PIXEL_FORMAT_RGBA_8888 */
	{ 4, 0, 8, 8, 8, 16, 8, 0, 0 }, /* HAL_PIXEL_FORMAT_RGBX_8888 */
	{ 3, 0, 8, 8, 8, 16, 8, 0, 0 }, /* HAL_PIXEL_FORMAT_RGB_888 */
	{ 2, 11, 5, 5, 6, 0, 5, 0, 0 }, /* HAL_PIXEL_FORMAT_RGB_565 */
	{ 4, 16, 8, 8, 8, 0, 8, 24, 8 }, /* HAL_PIXEL_FORMAT_BGRA_8888 */
	};

	if (format > 0 &&
	format < sizeof(fb_configs) / sizeof(struct framebuffer_config)) {
	return &fb_configs[format];
	}

	return &fb_configs[HAL_PIXEL_FORMAT_RGB_565]; /* legacy default */
	}

	struct goldfish_fb {
	void __iomem *reg_base;
	int irq;
	spinlock_t lock;
	wait_queue_head_t wait;
	int base_update_count;
	int rotation;
	struct fb_info fb;
	u32 cmap[16];
	};

	static irqreturn_t goldfish_fb_interrupt(int irq, void *dev_id)
	{
	unsigned long irq_flags;
	struct goldfish_fb *fb = dev_id;
	u32 status;

	spin_lock_irqsave(&fb->lock, irq_flags);
	status = readl(fb->reg_base + FB_INT_STATUS);
	if (status & FB_INT_BASE_UPDATE_DONE) {
	fb->base_update_count++;
	wake_up(&fb->wait);
	}
	spin_unlock_irqrestore(&fb->lock, irq_flags);
	return status ? IRQ_HANDLED : IRQ_NONE;
	}

	static inline u32 convert_bitfield(int val, struct fb_bitfield *bf)
	{
	unsigned int mask = (1 << bf->length) - 1;

	return (val >> (16 - bf->length) & mask) << bf->offset;
	}

	static int
	goldfish_fb_setcolreg(unsigned int regno, unsigned int red, unsigned int green,
	unsigned int blue, unsigned int transp, struct fb_info *info)
	{
	struct goldfish_fb *fb = container_of(info, struct goldfish_fb, fb);

	if (regno < 16) {
	fb->cmap[regno] = convert_bitfield(transp, &fb->fb.var.transp) \|
	convert_bitfield(blue, &fb->fb.var.blue) \|
	convert_bitfield(green, &fb->fb.var.green) \|
	convert_bitfield(red, &fb->fb.var.red);
	return 0;
	} else {
	return 1;
	}
	}

	static int goldfish_fb_check_var(struct fb_var_screeninfo *var,
	struct fb_info *info)
	{
	if ((var->rotate & 1) != (info->var.rotate & 1)) {
	if ((var->xres != info->var.yres) \|\|
	(var->yres != info->var.xres) \|\|
	(var->xres_virtual != info->var.yres) \|\|
	(var->yres_virtual > info->var.xres * 2) \|\|
	(var->yres_virtual < info->var.xres)) {
	return -EINVAL;
	}
	} else {
	if ((var->xres != info->var.xres) \|\|
	(var->yres != info->var.yres) \|\|
	(var->xres_virtual != info->var.xres) \|\|
	(var->yres_virtual > info->var.yres * 2) \|\|
	(var->yres_virtual < info->var.yres)) {
	return -EINVAL;
	}
	}
	if ((var->xoffset != info->var.xoffset) \|\|
	(var->bits_per_pixel != info->var.bits_per_pixel) \|\|
	(var->grayscale != info->var.grayscale)) {
	return -EINVAL;
	}
	return 0;
	}

	static int goldfish_fb_set_par(struct fb_info *info)
	{
	struct goldfish_fb *fb = container_of(info, struct goldfish_fb, fb);

	if (fb->rotation != fb->fb.var.rotate) {
	info->fix.line_length = info->var.xres *
	(fb->fb.var.bits_per_pixel / CHAR_BIT);
	fb->rotation = fb->fb.var.rotate;
	writel(fb->rotation, fb->reg_base + FB_SET_ROTATION);
	}
	return 0;
	}


	static int goldfish_fb_pan_display(struct fb_var_screeninfo *var,
	struct fb_info *info)
	{
	unsigned long irq_flags;
	int base_update_count;
	struct goldfish_fb *fb = container_of(info, struct goldfish_fb, fb);

	spin_lock_irqsave(&fb->lock, irq_flags);
	base_update_count = fb->base_update_count;
	writel(fb->fb.fix.smem_start +
	fb->fb.var.xres *
	(fb->fb.var.bits_per_pixel / CHAR_BIT) *
	var->yoffset,
	fb->reg_base + FB_SET_BASE);
	spin_unlock_irqrestore(&fb->lock, irq_flags);
	wait_event_timeout(fb->wait,
	fb->base_update_count != base_update_count, HZ / 15);
	if (fb->base_update_count == base_update_count)
	pr_err("goldfish_fb_pan_display: timeout waiting for "
	"base update\n");
	return 0;
	}

	static int goldfish_fb_blank(int blank, struct fb_info *info)
	{
	struct goldfish_fb *fb = container_of(info, struct goldfish_fb, fb);

	switch (blank) {
	case FB_BLANK_NORMAL:
	writel(1, fb->reg_base + FB_SET_BLANK);
	break;
	case FB_BLANK_UNBLANK:
	writel(0, fb->reg_base + FB_SET_BLANK);
	break;
	}
	return 0;
	}

	static struct fb_ops goldfish_fb_ops = {
	.owner = THIS_MODULE,
	.fb_check_var = goldfish_fb_check_var,
	.fb_set_par = goldfish_fb_set_par,
	.fb_setcolreg = goldfish_fb_setcolreg,
	.fb_pan_display = goldfish_fb_pan_display,
	.fb_blank = goldfish_fb_blank,
	.fb_fillrect = cfb_fillrect,
	.fb_copyarea = cfb_copyarea,
	.fb_imageblit = cfb_imageblit,
	};


	static int goldfish_fb_probe(struct platform_device *pdev)
	{
	int ret;
	struct resource *r;
	struct goldfish_fb *fb;
	size_t framesize;
	u32 width, height, format;
	int bytes_per_pixel;
	dma_addr_t fbpaddr;
	const struct framebuffer_config *fb_config;

	fb = kzalloc(sizeof(*fb), GFP_KERNEL);
	if (fb == NULL) {
	ret = -ENOMEM;
	goto err_fb_alloc_failed;
	}
	spin_lock_init(&fb->lock);
	init_waitqueue_head(&fb->wait);
	platform_set_drvdata(pdev, fb);

	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (r == NULL) {
	ret = -ENODEV;
	goto err_no_io_base;
	}
	fb->reg_base = ioremap(r->start, PAGE_SIZE);
	if (fb->reg_base == NULL) {
	ret = -ENOMEM;
	goto err_no_io_base;
	}

	fb->irq = platform_get_irq(pdev, 0);
	if (fb->irq <= 0) {
	ret = -ENODEV;
	goto err_no_irq;
	}

	width = readl(fb->reg_base + FB_GET_WIDTH);
	height = readl(fb->reg_base + FB_GET_HEIGHT);
	format = readl(fb->reg_base + FB_GET_FORMAT);
	fb_config = get_fb_config_from_format(format);
	if (!fb_config) {
	ret = -EINVAL;
	goto err_no_irq;
	}
	bytes_per_pixel = fb_config->bytes_per_pixel;

	fb->fb.fbops = &goldfish_fb_ops;
	fb->fb.flags = FBINFO_FLAG_DEFAULT;
	fb->fb.pseudo_palette = fb->cmap;
	fb->fb.fix.type = FB_TYPE_PACKED_PIXELS;
	fb->fb.fix.visual = FB_VISUAL_TRUECOLOR;
	fb->fb.fix.line_length = width * bytes_per_pixel;
	fb->fb.fix.accel = FB_ACCEL_NONE;
	fb->fb.fix.ypanstep = 1;

	fb->fb.var.xres = width;
	fb->fb.var.yres = height;
	fb->fb.var.xres_virtual = width;
	fb->fb.var.yres_virtual = height * 2;
	fb->fb.var.bits_per_pixel = bytes_per_pixel * CHAR_BIT;
	fb->fb.var.activate = FB_ACTIVATE_NOW;
	fb->fb.var.height = readl(fb->reg_base + FB_GET_PHYS_HEIGHT);
	fb->fb.var.width = readl(fb->reg_base + FB_GET_PHYS_WIDTH);
	fb->fb.var.pixclock = 0;

	fb->fb.var.red.offset = fb_config->red_offset;
	fb->fb.var.red.length = fb_config->red_length;
	fb->fb.var.green.offset = fb_config->green_offset;
	fb->fb.var.green.length = fb_config->green_length;
	fb->fb.var.blue.offset = fb_config->blue_offset;
	fb->fb.var.blue.length = fb_config->blue_length;
	fb->fb.var.transp.offset = fb_config->transp_offset;
	fb->fb.var.transp.length = fb_config->transp_length;

	framesize = width * height * 2 * bytes_per_pixel;
	fb->fb.screen_base = (char __force __iomem *)dma_alloc_coherent(
	&pdev->dev, framesize,
	&fbpaddr, GFP_KERNEL);
	pr_debug("allocating frame buffer %d * %d, got %p\n",
	width, height, fb->fb.screen_base);
	if (fb->fb.screen_base == NULL) {
	ret = -ENOMEM;
	goto err_alloc_screen_base_failed;
	}
	fb->fb.fix.smem_start = fbpaddr;
	fb->fb.fix.smem_len = framesize;

	ret = fb_set_var(&fb->fb, &fb->fb.var);
	if (ret)
	goto err_fb_set_var_failed;

	ret = request_irq(fb->irq, goldfish_fb_interrupt, IRQF_SHARED,
	pdev->name, fb);
	if (ret)
	goto err_request_irq_failed;

	writel(FB_INT_BASE_UPDATE_DONE, fb->reg_base + FB_INT_ENABLE);
	goldfish_fb_pan_display(&fb->fb.var, &fb->fb); /* updates base */

	ret = register_framebuffer(&fb->fb);
	if (ret)
	goto err_register_framebuffer_failed;
	return 0;

	err_register_framebuffer_failed:
	free_irq(fb->irq, fb);
	err_request_irq_failed:
	err_fb_set_var_failed:
	dma_free_coherent(&pdev->dev, framesize,
	(void *)fb->fb.screen_base,
	fb->fb.fix.smem_start);
	err_alloc_screen_base_failed:
	err_no_irq:
	iounmap(fb->reg_base);
	err_no_io_base:
	kfree(fb);
	err_fb_alloc_failed:
	return ret;
	}

	static int goldfish_fb_remove(struct platform_device *pdev)
	{
	size_t framesize;
	struct goldfish_fb *fb = platform_get_drvdata(pdev);

	framesize = fb->fb.var.xres_virtual * fb->fb.var.yres_virtual *
	(fb->fb.var.bits_per_pixel / CHAR_BIT);
	unregister_framebuffer(&fb->fb);
	free_irq(fb->irq, fb);

	dma_free_coherent(&pdev->dev, framesize, (void *)fb->fb.screen_base,
	fb->fb.fix.smem_start);
	iounmap(fb->reg_base);
	kfree(fb);
	return 0;
	}

	static const struct of_device_id goldfish_fb_of_match[] = {
	{ .compatible = "google,goldfish-fb", },
	{},
	};
	MODULE_DEVICE_TABLE(of, goldfish_fb_of_match);

	static const struct acpi_device_id goldfish_fb_acpi_match[] = {
	{ "GFSH0004", 0 },
	{ },
	};
	MODULE_DEVICE_TABLE(acpi, goldfish_fb_acpi_match);

	static struct platform_driver goldfish_fb_driver = {
	.probe = goldfish_fb_probe,
	.remove = goldfish_fb_remove,
	.driver = {
	.name = "goldfish_fb",
	.of_match_table = goldfish_fb_of_match,
	.acpi_match_table = ACPI_PTR(goldfish_fb_acpi_match),
	}
	};

	module_platform_driver(goldfish_fb_driver);

	MODULE_LICENSE("GPL v2");