text: /*
   * 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>
  
  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_INT_VSYNC             = 1U << 0,
  	FB_INT_BASE_UPDATE_DONE  = 1U << 1
  };
  
  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 * 2;
  		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 * 2 * 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;
  	dma_addr_t fbpaddr;
  
  	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);
  
  	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 * 2;
  	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 = 16;
  	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 = 11;
  	fb->fb.var.red.length = 5;
  	fb->fb.var.green.offset = 5;
  	fb->fb.var.green.length = 6;
  	fb->fb.var.blue.offset = 0;
  	fb->fb.var.blue.length = 5;
  
  	framesize = width * height * 2 * 2;
  	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 * 2;
  	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 struct platform_driver goldfish_fb_driver = {
  	.probe		= goldfish_fb_probe,
  	.remove		= goldfish_fb_remove,
  	.driver = {
  		.name = "goldfish_fb"
  	}
  };
  
  module_platform_driver(goldfish_fb_driver);
  
  MODULE_LICENSE("GPL v2");
  