acornfb.c

Linux环境下视频显示卡设备的驱动程序源代码

	.yres =		480,
	.pixclock =	39722,
	.left_margin =	56,
	.right_margin =	16,
	.upper_margin =	34,
	.lower_margin =	9,
	.hsync_len =	88,
	.vsync_len =	2,
	.sync =		0,
	.vmode =	FB_VMODE_NONINTERLACED
};

static void __init acornfb_init_fbinfo(void)
{
	static int first = 1;

	if (!first)
		return;
	first = 0;

	fb_info.fbops		= &acornfb_ops;
	fb_info.flags		= FBINFO_DEFAULT | FBINFO_HWACCEL_YPAN;
	fb_info.pseudo_palette	= current_par.pseudo_palette;

	strcpy(fb_info.fix.id, "Acorn");
	fb_info.fix.type	= FB_TYPE_PACKED_PIXELS;
	fb_info.fix.type_aux	= 0;
	fb_info.fix.xpanstep	= 0;
	fb_info.fix.ypanstep	= 1;
	fb_info.fix.ywrapstep	= 1;
	fb_info.fix.line_length	= 0;
	fb_info.fix.accel	= FB_ACCEL_NONE;

	/*
	 * setup initial parameters
	 */
	memset(&fb_info.var, 0, sizeof(fb_info.var));

#if defined(HAS_VIDC20)
	fb_info.var.red.length	   = 8;
	fb_info.var.transp.length  = 4;
#elif defined(HAS_VIDC)
	fb_info.var.red.length	   = 4;
	fb_info.var.transp.length  = 1;
#endif
	fb_info.var.green	   = fb_info.var.red;
	fb_info.var.blue	   = fb_info.var.red;
	fb_info.var.nonstd	   = 0;
	fb_info.var.activate	   = FB_ACTIVATE_NOW;
	fb_info.var.height	   = -1;
	fb_info.var.width	   = -1;
	fb_info.var.vmode	   = FB_VMODE_NONINTERLACED;
	fb_info.var.accel_flags	   = FB_ACCELF_TEXT;

	current_par.dram_size	   = 0;
	current_par.montype	   = -1;
	current_par.dpms	   = 0;
}

/*
 * setup acornfb options:
 *
 *  mon:hmin-hmax:vmin-vmax:dpms:width:height
 *	Set monitor parameters:
 *		hmin   = horizontal minimum frequency (Hz)
 *		hmax   = horizontal maximum frequency (Hz)	(optional)
 *		vmin   = vertical minimum frequency (Hz)
 *		vmax   = vertical maximum frequency (Hz)	(optional)
 *		dpms   = DPMS supported?			(optional)
 *		width  = width of picture in mm.		(optional)
 *		height = height of picture in mm.		(optional)
 *
 * montype:type
 *	Set RISC-OS style monitor type:
 *		0 (or tv)	- TV frequency
 *		1 (or multi)	- Multi frequency
 *		2 (or hires)	- Hi-res monochrome
 *		3 (or vga)	- VGA
 *		4 (or svga)	- SVGA
 *		auto, or option missing
 *				- try hardware detect
 *
 * dram:size
 *	Set the amount of DRAM to use for the frame buffer
 *	(even if you have VRAM).
 *	size can optionally be followed by 'M' or 'K' for
 *	MB or KB respectively.
 */
static void __init
acornfb_parse_mon(char *opt)
{
	char *p = opt;

	current_par.montype = -2;

	fb_info.monspecs.hfmin = simple_strtoul(p, &p, 0);
	if (*p == '-')
		fb_info.monspecs.hfmax = simple_strtoul(p + 1, &p, 0);
	else
		fb_info.monspecs.hfmax = fb_info.monspecs.hfmin;

	if (*p != ':')
		goto bad;

	fb_info.monspecs.vfmin = simple_strtoul(p + 1, &p, 0);
	if (*p == '-')
		fb_info.monspecs.vfmax = simple_strtoul(p + 1, &p, 0);
	else
		fb_info.monspecs.vfmax = fb_info.monspecs.vfmin;

	if (*p != ':')
		goto check_values;

	fb_info.monspecs.dpms = simple_strtoul(p + 1, &p, 0);

	if (*p != ':')
		goto check_values;

	fb_info.var.width = simple_strtoul(p + 1, &p, 0);

	if (*p != ':')
		goto check_values;

	fb_info.var.height = simple_strtoul(p + 1, NULL, 0);

check_values:
	if (fb_info.monspecs.hfmax < fb_info.monspecs.hfmin ||
	    fb_info.monspecs.vfmax < fb_info.monspecs.vfmin)
		goto bad;
	return;

bad:
	printk(KERN_ERR "Acornfb: bad monitor settings: %s\n", opt);
	current_par.montype = -1;
}

static void __init
acornfb_parse_montype(char *opt)
{
	current_par.montype = -2;

	if (strncmp(opt, "tv", 2) == 0) {
		opt += 2;
		current_par.montype = 0;
	} else if (strncmp(opt, "multi", 5) == 0) {
		opt += 5;
		current_par.montype = 1;
	} else if (strncmp(opt, "hires", 5) == 0) {
		opt += 5;
		current_par.montype = 2;
	} else if (strncmp(opt, "vga", 3) == 0) {
		opt += 3;
		current_par.montype = 3;
	} else if (strncmp(opt, "svga", 4) == 0) {
		opt += 4;
		current_par.montype = 4;
	} else if (strncmp(opt, "auto", 4) == 0) {
		opt += 4;
		current_par.montype = -1;
	} else if (isdigit(*opt))
		current_par.montype = simple_strtoul(opt, &opt, 0);

	if (current_par.montype == -2 ||
	    current_par.montype > NR_MONTYPES) {
		printk(KERN_ERR "acornfb: unknown monitor type: %s\n",
			opt);
		current_par.montype = -1;
	} else
	if (opt && *opt) {
		if (strcmp(opt, ",dpms") == 0)
			current_par.dpms = 1;
		else
			printk(KERN_ERR
			       "acornfb: unknown monitor option: %s\n",
			       opt);
	}
}

static void __init
acornfb_parse_dram(char *opt)
{
	unsigned int size;

	size = simple_strtoul(opt, &opt, 0);

	if (opt) {
		switch (*opt) {
		case 'M':
		case 'm':
			size *= 1024;
		case 'K':
		case 'k':
			size *= 1024;
		default:
			break;
		}
	}

	current_par.dram_size = size;
}

static struct options {
	char *name;
	void (*parse)(char *opt);
} opt_table[] __initdata = {
	{ "mon",     acornfb_parse_mon     },
	{ "montype", acornfb_parse_montype },
	{ "dram",    acornfb_parse_dram    },
	{ NULL, NULL }
};

int __init
acornfb_setup(char *options)
{
	struct options *optp;
	char *opt;

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

	acornfb_init_fbinfo();

	while ((opt = strsep(&options, ",")) != NULL) {
		if (!*opt)
			continue;

		for (optp = opt_table; optp->name; optp++) {
			int optlen;

			optlen = strlen(optp->name);

			if (strncmp(opt, optp->name, optlen) == 0 &&
			    opt[optlen] == ':') {
				optp->parse(opt + optlen + 1);
				break;
			}
		}

		if (!optp->name)
			printk(KERN_ERR "acornfb: unknown parameter: %s\n",
			       opt);
	}
	return 0;
}

/*
 * Detect type of monitor connected
 *  For now, we just assume SVGA
 */
static int __init
acornfb_detect_monitortype(void)
{
	return 4;
}

/*
 * This enables the unused memory to be freed on older Acorn machines.
 * We are freeing memory on behalf of the architecture initialisation
 * code here.
 */
static inline void
free_unused_pages(unsigned int virtual_start, unsigned int virtual_end)
{
	int mb_freed = 0;

	/*
	 * Align addresses
	 */
	virtual_start = PAGE_ALIGN(virtual_start);
	virtual_end = PAGE_ALIGN(virtual_end);

	while (virtual_start < virtual_end) {
		struct page *page;

		/*
		 * Clear page reserved bit,
		 * set count to 1, and free
		 * the page.
		 */
		page = virt_to_page(virtual_start);
		ClearPageReserved(page);
		init_page_count(page);
		free_page(virtual_start);

		virtual_start += PAGE_SIZE;
		mb_freed += PAGE_SIZE / 1024;
	}

	printk("acornfb: freed %dK memory\n", mb_freed);
}

static int __init acornfb_probe(struct platform_device *dev)
{
	unsigned long size;
	u_int h_sync, v_sync;
	int rc, i;
	char *option = NULL;

	if (fb_get_options("acornfb", &option))
		return -ENODEV;
	acornfb_setup(option);

	acornfb_init_fbinfo();

	current_par.dev = &dev->dev;

	if (current_par.montype == -1)
		current_par.montype = acornfb_detect_monitortype();

	if (current_par.montype == -1 || current_par.montype > NR_MONTYPES)
		current_par.montype = 4;

	if (current_par.montype >= 0) {
		fb_info.monspecs = monspecs[current_par.montype];
		fb_info.monspecs.dpms = current_par.dpms;
	}

	/*
	 * Try to select a suitable default mode
	 */
	for (i = 0; i < ARRAY_SIZE(modedb); i++) {
		unsigned long hs;

		hs = modedb[i].refresh *
		     (modedb[i].yres + modedb[i].upper_margin +
		      modedb[i].lower_margin + modedb[i].vsync_len);
		if (modedb[i].xres == DEFAULT_XRES &&
		    modedb[i].yres == DEFAULT_YRES &&
		    modedb[i].refresh >= fb_info.monspecs.vfmin &&
		    modedb[i].refresh <= fb_info.monspecs.vfmax &&
		    hs                >= fb_info.monspecs.hfmin &&
		    hs                <= fb_info.monspecs.hfmax) {
			acornfb_default_mode = modedb[i];
			break;
		}
	}

	fb_info.screen_base    = (char *)SCREEN_BASE;
	fb_info.fix.smem_start = SCREEN_START;
	current_par.using_vram = 0;

	/*
	 * If vram_size is set, we are using VRAM in
	 * a Risc PC.  However, if the user has specified
	 * an amount of DRAM then use that instead.
	 */
	if (vram_size && !current_par.dram_size) {
		size = vram_size;
		current_par.vram_half_sam = vram_size / 1024;
		current_par.using_vram = 1;
	} else if (current_par.dram_size)
		size = current_par.dram_size;
	else
		size = MAX_SIZE;

	/*
	 * Limit maximum screen size.
	 */
	if (size > MAX_SIZE)
		size = MAX_SIZE;

	size = PAGE_ALIGN(size);

#if defined(HAS_VIDC20)
	if (!current_par.using_vram) {
		dma_addr_t handle;
		void *base;

		/*
		 * RiscPC needs to allocate the DRAM memory
		 * for the framebuffer if we are not using
		 * VRAM.
		 */
		base = dma_alloc_writecombine(current_par.dev, size, &handle,
					      GFP_KERNEL);
		if (base == NULL) {
			printk(KERN_ERR "acornfb: unable to allocate screen "
			       "memory\n");
			return -ENOMEM;
		}

		fb_info.screen_base = base;
		fb_info.fix.smem_start = handle;
	}
#endif
#if defined(HAS_VIDC)
	/*
	 * Archimedes/A5000 machines use a fixed address for their
	 * framebuffers.  Free unused pages
	 */
	free_unused_pages(PAGE_OFFSET + size, PAGE_OFFSET + MAX_SIZE);
#endif

	fb_info.fix.smem_len = size;
	current_par.palette_size   = VIDC_PALETTE_SIZE;

	/*
	 * Lookup the timing for this resolution.  If we can't
	 * find it, then we can't restore it if we change
	 * the resolution, so we disable this feature.
	 */
	do {
		rc = fb_find_mode(&fb_info.var, &fb_info, NULL, modedb,
				 ARRAY_SIZE(modedb),
				 &acornfb_default_mode, DEFAULT_BPP);
		/*
		 * If we found an exact match, all ok.
		 */
		if (rc == 1)
			break;

		rc = fb_find_mode(&fb_info.var, &fb_info, NULL, NULL, 0,
				  &acornfb_default_mode, DEFAULT_BPP);
		/*
		 * If we found an exact match, all ok.
		 */
		if (rc == 1)
			break;

		rc = fb_find_mode(&fb_info.var, &fb_info, NULL, modedb,
				 ARRAY_SIZE(modedb),
				 &acornfb_default_mode, DEFAULT_BPP);
		if (rc)
			break;

		rc = fb_find_mode(&fb_info.var, &fb_info, NULL, NULL, 0,
				  &acornfb_default_mode, DEFAULT_BPP);
	} while (0);

	/*
	 * If we didn't find an exact match, try the
	 * generic database.
	 */
	if (rc == 0) {
		printk("Acornfb: no valid mode found\n");
		return -EINVAL;
	}

	h_sync = 1953125000 / fb_info.var.pixclock;
	h_sync = h_sync * 512 / (fb_info.var.xres + fb_info.var.left_margin +
		 fb_info.var.right_margin + fb_info.var.hsync_len);
	v_sync = h_sync / (fb_info.var.yres + fb_info.var.upper_margin +
		 fb_info.var.lower_margin + fb_info.var.vsync_len);

	printk(KERN_INFO "Acornfb: %dkB %cRAM, %s, using %dx%d, "
		"%d.%03dkHz, %dHz\n",
		fb_info.fix.smem_len / 1024,
		current_par.using_vram ? 'V' : 'D',
		VIDC_NAME, fb_info.var.xres, fb_info.var.yres,
		h_sync / 1000, h_sync % 1000, v_sync);

	printk(KERN_INFO "Acornfb: Monitor: %d.%03d-%d.%03dkHz, %d-%dHz%s\n",
		fb_info.monspecs.hfmin / 1000, fb_info.monspecs.hfmin % 1000,
		fb_info.monspecs.hfmax / 1000, fb_info.monspecs.hfmax % 1000,
		fb_info.monspecs.vfmin, fb_info.monspecs.vfmax,
		fb_info.monspecs.dpms ? ", DPMS" : "");

	if (fb_set_var(&fb_info, &fb_info.var))
		printk(KERN_ERR "Acornfb: unable to set display parameters\n");

	if (register_framebuffer(&fb_info) < 0)
		return -EINVAL;
	return 0;
}

static struct platform_driver acornfb_driver = {
	.probe	= acornfb_probe,
	.driver	= {
		.name	= "acornfb",
	},
};

static int __init acornfb_init(void)
{
	return platform_driver_register(&acornfb_driver);
}

module_init(acornfb_init);

MODULE_AUTHOR("Russell King");
MODULE_DESCRIPTION("VIDC 1/1a/20 framebuffer driver");
MODULE_LICENSE("GPL");