gbefb.c

Linux环境下视频显示卡设备的驱动程序源代码

				udelay(10);
			if (i == 1000) {
				printk(KERN_ERR "gbefb: cmap FIFO timeout\n");
				return 1;
			}
			gbe->cmap[regno] = gbe_cmap[regno];
		}
	} else if (regno < 16) {
		switch (info->var.bits_per_pixel) {
		case 15:
		case 16:
			red >>= 3;
			green >>= 3;
			blue >>= 3;
			pseudo_palette[regno] =
				(red << info->var.red.offset) |
				(green << info->var.green.offset) |
				(blue << info->var.blue.offset);
			break;
		case 32:
			pseudo_palette[regno] =
				(red << info->var.red.offset) |
				(green << info->var.green.offset) |
				(blue << info->var.blue.offset);
			break;
		}
	}

	return 0;
}

/*
 *  Check video mode validity, eventually modify var to best match.
 */
static int gbefb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
{
	unsigned int line_length;
	struct gbe_timing_info timing;
	int ret;

	/* Limit bpp to 8, 16, and 32 */
	if (var->bits_per_pixel <= 8)
		var->bits_per_pixel = 8;
	else if (var->bits_per_pixel <= 16)
		var->bits_per_pixel = 16;
	else if (var->bits_per_pixel <= 32)
		var->bits_per_pixel = 32;
	else
		return -EINVAL;

	/* Check the mode can be mapped linearly with the tile table trick. */
	/* This requires width x height x bytes/pixel be a multiple of 512 */
	if ((var->xres * var->yres * var->bits_per_pixel) & 4095)
		return -EINVAL;

	var->grayscale = 0;	/* No grayscale for now */

	ret = compute_gbe_timing(var, &timing);
	var->pixclock = ret;
	if (ret < 0)
		return -EINVAL;

	/* Adjust virtual resolution, if necessary */
	if (var->xres > var->xres_virtual || (!ywrap && !ypan))
		var->xres_virtual = var->xres;
	if (var->yres > var->yres_virtual || (!ywrap && !ypan))
		var->yres_virtual = var->yres;

	if (var->vmode & FB_VMODE_CONUPDATE) {
		var->vmode |= FB_VMODE_YWRAP;
		var->xoffset = info->var.xoffset;
		var->yoffset = info->var.yoffset;
	}

	/* No grayscale for now */
	var->grayscale = 0;

	/* Memory limit */
	line_length = var->xres_virtual * var->bits_per_pixel / 8;
	if (line_length * var->yres_virtual > gbe_mem_size)
		return -ENOMEM;	/* Virtual resolution too high */

	switch (var->bits_per_pixel) {
	case 8:
		var->red.offset = 0;
		var->red.length = 8;
		var->green.offset = 0;
		var->green.length = 8;
		var->blue.offset = 0;
		var->blue.length = 8;
		var->transp.offset = 0;
		var->transp.length = 0;
		break;
	case 16:		/* RGB 1555 */
		var->red.offset = 10;
		var->red.length = 5;
		var->green.offset = 5;
		var->green.length = 5;
		var->blue.offset = 0;
		var->blue.length = 5;
		var->transp.offset = 0;
		var->transp.length = 0;
		break;
	case 32:		/* RGB 8888 */
		var->red.offset = 24;
		var->red.length = 8;
		var->green.offset = 16;
		var->green.length = 8;
		var->blue.offset = 8;
		var->blue.length = 8;
		var->transp.offset = 0;
		var->transp.length = 8;
		break;
	}
	var->red.msb_right = 0;
	var->green.msb_right = 0;
	var->blue.msb_right = 0;
	var->transp.msb_right = 0;

	var->left_margin = timing.htotal - timing.hsync_end;
	var->right_margin = timing.hsync_start - timing.width;
	var->upper_margin = timing.vtotal - timing.vsync_end;
	var->lower_margin = timing.vsync_start - timing.height;
	var->hsync_len = timing.hsync_end - timing.hsync_start;
	var->vsync_len = timing.vsync_end - timing.vsync_start;

	return 0;
}

static int gbefb_mmap(struct fb_info *info,
			struct vm_area_struct *vma)
{
	unsigned long size = vma->vm_end - vma->vm_start;
	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
	unsigned long addr;
	unsigned long phys_addr, phys_size;
	u16 *tile;

	/* check range */
	if (vma->vm_pgoff > (~0UL >> PAGE_SHIFT))
		return -EINVAL;
	if (offset + size > gbe_mem_size)
		return -EINVAL;

	/* remap using the fastest write-through mode on architecture */
	/* try not polluting the cache when possible */
	pgprot_val(vma->vm_page_prot) =
		pgprot_fb(pgprot_val(vma->vm_page_prot));

	vma->vm_flags |= VM_IO | VM_RESERVED;

	/* look for the starting tile */
	tile = &gbe_tiles.cpu[offset >> TILE_SHIFT];
	addr = vma->vm_start;
	offset &= TILE_MASK;

	/* remap each tile separately */
	do {
		phys_addr = (((unsigned long) (*tile)) << TILE_SHIFT) + offset;
		if ((offset + size) < TILE_SIZE)
			phys_size = size;
		else
			phys_size = TILE_SIZE - offset;

		if (remap_pfn_range(vma, addr, phys_addr >> PAGE_SHIFT,
						phys_size, vma->vm_page_prot))
			return -EAGAIN;

		offset = 0;
		size -= phys_size;
		addr += phys_size;
		tile++;
	} while (size);

	return 0;
}

static struct fb_ops gbefb_ops = {
	.owner		= THIS_MODULE,
	.fb_check_var	= gbefb_check_var,
	.fb_set_par	= gbefb_set_par,
	.fb_setcolreg	= gbefb_setcolreg,
	.fb_mmap	= gbefb_mmap,
	.fb_blank	= gbefb_blank,
	.fb_fillrect	= cfb_fillrect,
	.fb_copyarea	= cfb_copyarea,
	.fb_imageblit	= cfb_imageblit,
};

/*
 * sysfs
 */

static ssize_t gbefb_show_memsize(struct device *dev, struct device_attribute *attr, char *buf)
{
	return snprintf(buf, PAGE_SIZE, "%d\n", gbe_mem_size);
}

static DEVICE_ATTR(size, S_IRUGO, gbefb_show_memsize, NULL);

static ssize_t gbefb_show_rev(struct device *device, struct device_attribute *attr, char *buf)
{
	return snprintf(buf, PAGE_SIZE, "%d\n", gbe_revision);
}

static DEVICE_ATTR(revision, S_IRUGO, gbefb_show_rev, NULL);

static void __devexit gbefb_remove_sysfs(struct device *dev)
{
	device_remove_file(dev, &dev_attr_size);
	device_remove_file(dev, &dev_attr_revision);
}

static void gbefb_create_sysfs(struct device *dev)
{
	device_create_file(dev, &dev_attr_size);
	device_create_file(dev, &dev_attr_revision);
}

/*
 * Initialization
 */

int __init gbefb_setup(char *options)
{
	char *this_opt;

	if (!options || !*options)
		return 0;

	while ((this_opt = strsep(&options, ",")) != NULL) {
		if (!strncmp(this_opt, "monitor:", 8)) {
			if (!strncmp(this_opt + 8, "crt", 3)) {
				flat_panel_enabled = 0;
				default_var = &default_var_CRT;
				default_mode = &default_mode_CRT;
			} else if (!strncmp(this_opt + 8, "1600sw", 6) ||
				   !strncmp(this_opt + 8, "lcd", 3)) {
				flat_panel_enabled = 1;
				default_var = &default_var_LCD;
				default_mode = &default_mode_LCD;
			}
		} else if (!strncmp(this_opt, "mem:", 4)) {
			gbe_mem_size = memparse(this_opt + 4, &this_opt);
			if (gbe_mem_size > CONFIG_FB_GBE_MEM * 1024 * 1024)
				gbe_mem_size = CONFIG_FB_GBE_MEM * 1024 * 1024;
			if (gbe_mem_size < TILE_SIZE)
				gbe_mem_size = TILE_SIZE;
		} else
			mode_option = this_opt;
	}
	return 0;
}

static int __init gbefb_probe(struct platform_device *p_dev)
{
	int i, ret = 0;
	struct fb_info *info;
	struct gbefb_par *par;
#ifndef MODULE
	char *options = NULL;
#endif

	info = framebuffer_alloc(sizeof(struct gbefb_par), &p_dev->dev);
	if (!info)
		return -ENOMEM;

#ifndef MODULE
	if (fb_get_options("gbefb", &options))
		return -ENODEV;
	gbefb_setup(options);
#endif

	if (!request_region(GBE_BASE, sizeof(struct sgi_gbe), "GBE")) {
		printk(KERN_ERR "gbefb: couldn't reserve mmio region\n");
		ret = -EBUSY;
		goto out_release_framebuffer;
	}

	gbe = (struct sgi_gbe *) ioremap(GBE_BASE, sizeof(struct sgi_gbe));
	if (!gbe) {
		printk(KERN_ERR "gbefb: couldn't map mmio region\n");
		ret = -ENXIO;
		goto out_release_mem_region;
	}
	gbe_revision = gbe->ctrlstat & 15;

	gbe_tiles.cpu =
		dma_alloc_coherent(NULL, GBE_TLB_SIZE * sizeof(uint16_t),
				   &gbe_tiles.dma, GFP_KERNEL);
	if (!gbe_tiles.cpu) {
		printk(KERN_ERR "gbefb: couldn't allocate tiles table\n");
		ret = -ENOMEM;
		goto out_unmap;
	}

	if (gbe_mem_phys) {
		/* memory was allocated at boot time */
		gbe_mem = ioremap_nocache(gbe_mem_phys, gbe_mem_size);
		if (!gbe_mem) {
			printk(KERN_ERR "gbefb: couldn't map framebuffer\n");
			ret = -ENOMEM;
			goto out_tiles_free;
		}

		gbe_dma_addr = 0;
	} else {
		/* try to allocate memory with the classical allocator
		 * this has high chance to fail on low memory machines */
		gbe_mem = dma_alloc_coherent(NULL, gbe_mem_size, &gbe_dma_addr,
					     GFP_KERNEL);
		if (!gbe_mem) {
			printk(KERN_ERR "gbefb: couldn't allocate framebuffer memory\n");
			ret = -ENOMEM;
			goto out_tiles_free;
		}

		gbe_mem_phys = (unsigned long) gbe_dma_addr;
	}

#ifdef CONFIG_X86
	mtrr_add(gbe_mem_phys, gbe_mem_size, MTRR_TYPE_WRCOMB, 1);
#endif

	/* map framebuffer memory into tiles table */
	for (i = 0; i < (gbe_mem_size >> TILE_SHIFT); i++)
		gbe_tiles.cpu[i] = (gbe_mem_phys >> TILE_SHIFT) + i;

	info->fbops = &gbefb_ops;
	info->pseudo_palette = pseudo_palette;
	info->flags = FBINFO_DEFAULT;
	info->screen_base = gbe_mem;
	fb_alloc_cmap(&info->cmap, 256, 0);

	/* reset GBE */
	gbe_reset();

	par = info->par;
	/* turn on default video mode */
	if (fb_find_mode(&par->var, info, mode_option, NULL, 0,
			 default_mode, 8) == 0)
		par->var = *default_var;
	info->var = par->var;
	gbefb_check_var(&par->var, info);
	gbefb_encode_fix(&info->fix, &info->var);

	if (register_framebuffer(info) < 0) {
		printk(KERN_ERR "gbefb: couldn't register framebuffer\n");
		ret = -ENXIO;
		goto out_gbe_unmap;
	}

	platform_set_drvdata(p_dev, info);
	gbefb_create_sysfs(&p_dev->dev);

	printk(KERN_INFO "fb%d: %s rev %d @ 0x%08x using %dkB memory\n",
	       info->node, info->fix.id, gbe_revision, (unsigned) GBE_BASE,
	       gbe_mem_size >> 10);

	return 0;

out_gbe_unmap:
	if (gbe_dma_addr)
		dma_free_coherent(NULL, gbe_mem_size, gbe_mem, gbe_mem_phys);
	else
		iounmap(gbe_mem);
out_tiles_free:
	dma_free_coherent(NULL, GBE_TLB_SIZE * sizeof(uint16_t),
			  (void *)gbe_tiles.cpu, gbe_tiles.dma);
out_unmap:
	iounmap(gbe);
out_release_mem_region:
	release_mem_region(GBE_BASE, sizeof(struct sgi_gbe));
out_release_framebuffer:
	framebuffer_release(info);

	return ret;
}

static int __devexit gbefb_remove(struct platform_device* p_dev)
{
	struct fb_info *info = platform_get_drvdata(p_dev);

	unregister_framebuffer(info);
	gbe_turn_off();
	if (gbe_dma_addr)
		dma_free_coherent(NULL, gbe_mem_size, gbe_mem, gbe_mem_phys);
	else
		iounmap(gbe_mem);
	dma_free_coherent(NULL, GBE_TLB_SIZE * sizeof(uint16_t),
			  (void *)gbe_tiles.cpu, gbe_tiles.dma);
	release_mem_region(GBE_BASE, sizeof(struct sgi_gbe));
	iounmap(gbe);
	gbefb_remove_sysfs(&p_dev->dev);
	framebuffer_release(info);

	return 0;
}

static struct platform_driver gbefb_driver = {
	.probe = gbefb_probe,
	.remove = __devexit_p(gbefb_remove),
	.driver	= {
		.name = "gbefb",
	},
};

static struct platform_device *gbefb_device;

int __init gbefb_init(void)
{
	int ret = platform_driver_register(&gbefb_driver);
	if (!ret) {
		gbefb_device = platform_device_alloc("gbefb", 0);
		if (gbefb_device) {
			ret = platform_device_add(gbefb_device);
		} else {
			ret = -ENOMEM;
		}
		if (ret) {
			platform_device_put(gbefb_device);
			platform_driver_unregister(&gbefb_driver);
		}
	}
	return ret;
}

void __exit gbefb_exit(void)
{
	platform_device_unregister(gbefb_device);
	platform_driver_unregister(&gbefb_driver);
}

module_init(gbefb_init);
module_exit(gbefb_exit);

MODULE_LICENSE("GPL");