metronomefb.c

Linux环境下视频显示卡设备的驱动程序源代码

	cs = 0xCC20;

	/* set the args ( 2 bytes ) for init */
	i = 0;
	par->metromem_cmd->args[i] = 0;
	cs += par->metromem_cmd->args[i++];

	/* the rest are 0 */
	memset((u8 *) (par->metromem_cmd->args + i), 0, (32-i)*2);

	par->metromem_cmd->csum = cs;
	par->metromem_cmd->opcode = 0xCC20; /* init cmd */

	return par->board->met_wait_event(par);
}

static int __devinit metronome_init_regs(struct metronomefb_par *par)
{
	int res;

	res = par->board->setup_io(par);
	if (res)
		return res;

	res = metronome_powerup_cmd(par);
	if (res)
		return res;

	res = metronome_config_cmd(par);
	if (res)
		return res;

	res = metronome_init_cmd(par);

	return res;
}

static void metronomefb_dpy_update(struct metronomefb_par *par)
{
	int fbsize;
	u16 cksum;
	unsigned char *buf = (unsigned char __force *)par->info->screen_base;

	fbsize = par->info->fix.smem_len;
	/* copy from vm to metromem */
	memcpy(par->metromem_img, buf, fbsize);

	cksum = calc_img_cksum((u16 *) par->metromem_img, fbsize/2);
	*((u16 *)(par->metromem_img) + fbsize/2) = cksum;
	metronome_display_cmd(par);
}

static u16 metronomefb_dpy_update_page(struct metronomefb_par *par, int index)
{
	int i;
	u16 csum = 0;
	u16 *buf = (u16 __force *)(par->info->screen_base + index);
	u16 *img = (u16 *)(par->metromem_img + index);

	/* swizzle from vm to metromem and recalc cksum at the same time*/
	for (i = 0; i < PAGE_SIZE/2; i++) {
		*(img + i) = (buf[i] << 5) & 0xE0E0;
		csum += *(img + i);
	}
	return csum;
}

/* this is called back from the deferred io workqueue */
static void metronomefb_dpy_deferred_io(struct fb_info *info,
				struct list_head *pagelist)
{
	u16 cksum;
	struct page *cur;
	struct fb_deferred_io *fbdefio = info->fbdefio;
	struct metronomefb_par *par = info->par;

	/* walk the written page list and swizzle the data */
	list_for_each_entry(cur, &fbdefio->pagelist, lru) {
		cksum = metronomefb_dpy_update_page(par,
					(cur->index << PAGE_SHIFT));
		par->metromem_img_csum -= par->csum_table[cur->index];
		par->csum_table[cur->index] = cksum;
		par->metromem_img_csum += cksum;
	}

	metronome_display_cmd(par);
}

static void metronomefb_fillrect(struct fb_info *info,
				   const struct fb_fillrect *rect)
{
	struct metronomefb_par *par = info->par;

	sys_fillrect(info, rect);
	metronomefb_dpy_update(par);
}

static void metronomefb_copyarea(struct fb_info *info,
				   const struct fb_copyarea *area)
{
	struct metronomefb_par *par = info->par;

	sys_copyarea(info, area);
	metronomefb_dpy_update(par);
}

static void metronomefb_imageblit(struct fb_info *info,
				const struct fb_image *image)
{
	struct metronomefb_par *par = info->par;

	sys_imageblit(info, image);
	metronomefb_dpy_update(par);
}

/*
 * this is the slow path from userspace. they can seek and write to
 * the fb. it is based on fb_sys_write
 */
static ssize_t metronomefb_write(struct fb_info *info, const char __user *buf,
				size_t count, loff_t *ppos)
{
	struct metronomefb_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;

	metronomefb_dpy_update(par);

	return (err) ? err : count;
}

static struct fb_ops metronomefb_ops = {
	.owner		= THIS_MODULE,
	.fb_write	= metronomefb_write,
	.fb_fillrect	= metronomefb_fillrect,
	.fb_copyarea	= metronomefb_copyarea,
	.fb_imageblit	= metronomefb_imageblit,
};

static struct fb_deferred_io metronomefb_defio = {
	.delay		= HZ,
	.deferred_io	= metronomefb_dpy_deferred_io,
};

static int __devinit metronomefb_probe(struct platform_device *dev)
{
	struct fb_info *info;
	struct metronome_board *board;
	int retval = -ENOMEM;
	int videomemorysize;
	unsigned char *videomemory;
	struct metronomefb_par *par;
	const struct firmware *fw_entry;
	int i;
	int panel_type;
	int fw, fh;
	int epd_dt_index;

	/* 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 metronomefb_par), &dev->dev);
	if (!info)
		goto err;

	/* we have two blocks of memory.
	info->screen_base which is vm, and is the fb used by apps.
	par->metromem which is physically contiguous memory and
	contains the display controller commands, waveform,
	processed image data and padding. this is the data pulled
	by the device's LCD controller and pushed to Metronome.
	the metromem memory is allocated by the board driver and
	is provided to us */

	panel_type = board->get_panel_type();
	switch (panel_type) {
	case 6:
		epd_dt_index = 0;
		break;
	case 8:
		epd_dt_index = 1;
		break;
	case 97:
		epd_dt_index = 2;
		break;
	default:
		dev_err(&dev->dev, "Unexpected panel type. Defaulting to 6\n");
		epd_dt_index = 0;
		break;
	}

	fw = epd_frame_table[epd_dt_index].fw;
	fh = epd_frame_table[epd_dt_index].fh;

	/* we need to add a spare page because our csum caching scheme walks
	 * to the end of the page */
	videomemorysize = PAGE_SIZE + (fw * fh);
	videomemory = vmalloc(videomemorysize);
	if (!videomemory)
		goto err_fb_rel;

	memset(videomemory, 0, videomemorysize);

	info->screen_base = (char __force __iomem *)videomemory;
	info->fbops = &metronomefb_ops;

	metronomefb_fix.line_length = fw;
	metronomefb_var.xres = fw;
	metronomefb_var.yres = fh;
	metronomefb_var.xres_virtual = fw;
	metronomefb_var.yres_virtual = fh;
	info->var = metronomefb_var;
	info->fix = metronomefb_fix;
	info->fix.smem_len = videomemorysize;
	par = info->par;
	par->info = info;
	par->board = board;
	par->dt = epd_dt_index;
	init_waitqueue_head(&par->waitq);

	/* this table caches per page csum values. */
	par->csum_table = vmalloc(videomemorysize/PAGE_SIZE);
	if (!par->csum_table)
		goto err_vfree;

	/* the physical framebuffer that we use is setup by
	 * the platform device driver. It will provide us
	 * with cmd, wfm and image memory in a contiguous area. */
	retval = board->setup_fb(par);
	if (retval) {
		dev_err(&dev->dev, "Failed to setup fb\n");
		goto err_csum_table;
	}

	/* after this point we should have a framebuffer */
	if ((!par->metromem_wfm) ||  (!par->metromem_img) ||
		(!par->metromem_dma)) {
		dev_err(&dev->dev, "fb access failure\n");
		retval = -EINVAL;
		goto err_csum_table;
	}

	info->fix.smem_start = par->metromem_dma;

	/* load the waveform in. assume mode 3, temp 31 for now
		a) request the waveform file from userspace
		b) process waveform and decode into metromem */
	retval = request_firmware(&fw_entry, "metronome.wbf", &dev->dev);
	if (retval < 0) {
		dev_err(&dev->dev, "Failed to get waveform\n");
		goto err_csum_table;
	}

	retval = load_waveform((u8 *) fw_entry->data, fw_entry->size, 3, 31,
				par);
	release_firmware(fw_entry);
	if (retval < 0) {
		dev_err(&dev->dev, "Failed processing waveform\n");
		goto err_csum_table;
	}

	if (board->setup_irq(info))
		goto err_csum_table;

	retval = metronome_init_regs(par);
	if (retval < 0)
		goto err_free_irq;

	info->flags = FBINFO_FLAG_DEFAULT;

	info->fbdefio = &metronomefb_defio;
	fb_deferred_io_init(info);

	retval = fb_alloc_cmap(&info->cmap, 8, 0);
	if (retval < 0) {
		dev_err(&dev->dev, "Failed to allocate colormap\n");
		goto err_free_irq;
	}

	/* set cmap */
	for (i = 0; i < 8; i++)
		info->cmap.red[i] = (((2*i)+1)*(0xFFFF))/16;
	memcpy(info->cmap.green, info->cmap.red, sizeof(u16)*8);
	memcpy(info->cmap.blue, info->cmap.red, sizeof(u16)*8);

	retval = register_framebuffer(info);
	if (retval < 0)
		goto err_cmap;

	platform_set_drvdata(dev, info);

	dev_dbg(&dev->dev,
		"fb%d: Metronome frame buffer device, using %dK of video"
		" memory\n", info->node, videomemorysize >> 10);

	return 0;

err_cmap:
	fb_dealloc_cmap(&info->cmap);
err_free_irq:
	board->cleanup(par);
err_csum_table:
	vfree(par->csum_table);
err_vfree:
	vfree(videomemory);
err_fb_rel:
	framebuffer_release(info);
err:
	module_put(board->owner);
	return retval;
}

static int __devexit metronomefb_remove(struct platform_device *dev)
{
	struct fb_info *info = platform_get_drvdata(dev);

	if (info) {
		struct metronomefb_par *par = info->par;

		unregister_framebuffer(info);
		fb_deferred_io_cleanup(info);
		fb_dealloc_cmap(&info->cmap);
		par->board->cleanup(par);
		vfree(par->csum_table);
		vfree((void __force *)info->screen_base);
		module_put(par->board->owner);
		dev_dbg(&dev->dev, "calling release\n");
		framebuffer_release(info);
	}
	return 0;
}

static struct platform_driver metronomefb_driver = {
	.probe	= metronomefb_probe,
	.remove = metronomefb_remove,
	.driver	= {
		.owner	= THIS_MODULE,
		.name	= "metronomefb",
	},
};

static int __init metronomefb_init(void)
{
	return platform_driver_register(&metronomefb_driver);
}

static void __exit metronomefb_exit(void)
{
	platform_driver_unregister(&metronomefb_driver);
}

module_param(user_wfm_size, uint, 0);
MODULE_PARM_DESC(user_wfm_size, "Set custom waveform size");

module_init(metronomefb_init);
module_exit(metronomefb_exit);

MODULE_DESCRIPTION("fbdev driver for Metronome controller");
MODULE_AUTHOR("Jaya Kumar");
MODULE_LICENSE("GPL");