acornfb.c

S3C44B0X下的LCD （framebuffer）驱动资料与相关代码

		cmap = &fb_display[current_par.currcon].cmap;

		if (cmap->len)
			fb_get_cmap(cmap, 1, acornfb_getcolreg, info);
	}

	current_par.currcon = con;

	fb_display[con].var.activate = FB_ACTIVATE_NOW;

	acornfb_set_var(&fb_display[con].var, con, info);

	return 0;
}

static void
acornfb_blank(int blank, struct fb_info *info)
{
	union palette p;
	int i, bpp = fb_display[current_par.currcon].var.bits_per_pixel;

#ifdef FBCON_HAS_CFB16
	if (bpp == 16) {
		p.p = 0;

		for (i = 0; i < 256; i++) {
			if (blank)
				p = acornfb_palette_encode(i, 0, 0, 0, 0);
			else {
				p.vidc20.red   = current_par.palette[ i       & 31].vidc20.red;
				p.vidc20.green = current_par.palette[(i >> 1) & 31].vidc20.green;
				p.vidc20.blue  = current_par.palette[(i >> 2) & 31].vidc20.blue;
			}
			acornfb_palette_write(i, current_par.palette[i]);
		}
	} else
#endif
	{
		for (i = 0; i < current_par.palette_size; i++) {
			if (blank)
				p = acornfb_palette_encode(i, 0, 0, 0, 0);
			else
				p = current_par.palette[i];

			acornfb_palette_write(i, p);
		}
	}
}

/*
 * Everything after here is initialisation!!!
 */
static struct fb_videomode modedb[] __initdata = {
	{	/* 320x256 @ 50Hz */
		NULL, 50,  320,  256, 125000,  92,  62,  35, 19,  38, 2,
		FB_SYNC_COMP_HIGH_ACT,
		FB_VMODE_NONINTERLACED
	}, {	/* 640x250 @ 50Hz, 15.6 kHz hsync */
		NULL, 50,  640,  250,  62500, 185, 123,  38, 21,  76, 3,
		0,
		FB_VMODE_NONINTERLACED
	}, {	/* 640x256 @ 50Hz, 15.6 kHz hsync */
		NULL, 50,  640,  256,  62500, 185, 123,  35, 18,  76, 3,
		0,
		FB_VMODE_NONINTERLACED
	}, {	/* 640x512 @ 50Hz, 26.8 kHz hsync */
		NULL, 50,  640,  512,  41667, 113,  87,  18,  1,  56, 3,
		0,
		FB_VMODE_NONINTERLACED
	}, {	/* 640x250 @ 70Hz, 31.5 kHz hsync */
		NULL, 70,  640,  250,  39722,  48,  16, 109, 88,  96, 2,
		0,
		FB_VMODE_NONINTERLACED
	}, {	/* 640x256 @ 70Hz, 31.5 kHz hsync */
		NULL, 70,  640,  256,  39722,  48,  16, 106, 85,  96, 2,
		0,
		FB_VMODE_NONINTERLACED
	}, {	/* 640x352 @ 70Hz, 31.5 kHz hsync */
		NULL, 70,  640,  352,  39722,  48,  16,  58, 37,  96, 2,
		0,
		FB_VMODE_NONINTERLACED
	}, {	/* 640x480 @ 60Hz, 31.5 kHz hsync */
		NULL, 60,  640,  480,  39722,  48,  16,  32, 11,  96, 2,
		0,
		FB_VMODE_NONINTERLACED
	}, {	/* 800x600 @ 56Hz, 35.2 kHz hsync */
		NULL, 56,  800,  600,  27778, 101,  23,  22,  1, 100, 2,
		0,
		FB_VMODE_NONINTERLACED
	}, {	/* 896x352 @ 60Hz, 21.8 kHz hsync */
		NULL, 60,  896,  352,  41667,  59,  27,   9,  0, 118, 3,
		0,
		FB_VMODE_NONINTERLACED
	}, {	/* 1024x 768 @ 60Hz, 48.4 kHz hsync */
		NULL, 60, 1024,  768,  15385, 160,  24,  29,  3, 136, 6,
		0,
		FB_VMODE_NONINTERLACED
	}, {	/* 1280x1024 @ 60Hz, 63.8 kHz hsync */
		NULL, 60, 1280, 1024,   9090, 186,  96,  38,  1, 160, 3,
		0,
		FB_VMODE_NONINTERLACED
	}
};

static struct fb_videomode __initdata
acornfb_default_mode = {
	name:		NULL,
	refresh:	60,
	xres:		640,
	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;

	strcpy(fb_info.modename, "Acorn");
	strcpy(fb_info.fontname, "Acorn8x8");

	fb_info.node		   = -1;
	fb_info.fbops		   = &acornfb_ops;
	fb_info.disp		   = &global_disp;
	fb_info.changevar	   = NULL;
	fb_info.switch_con	   = acornfb_switch;
	fb_info.updatevar	   = acornfb_updatevar;
	fb_info.blank		   = acornfb_blank;
	fb_info.flags		   = FBINFO_FLAG_DEFAULT;

	global_disp.dispsw	   = &fbcon_dummy;

	/*
	 * setup initial parameters
	 */
	memset(&init_var, 0, sizeof(init_var));

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

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

/*
 * setup acornfb options:
 *
 *  font:fontname
 *	Set fontname
 *
 *  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_font(char *opt)
{
	strcpy(fb_info.fontname, opt);
}

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;

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

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

	init_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 = {
	{ "font",    acornfb_parse_font    },
	{ "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.
 */
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);
		atomic_set(&page->count, 1);
		free_page(virtual_start);

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

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

int __init
acornfb_init(void)
{
	unsigned long size;
	u_int h_sync, v_sync;
	int rc, i;

	acornfb_init_fbinfo();

	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 < sizeof(modedb) / sizeof(*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;
		}
	}

	current_par.currcon	   = -1;
	current_par.screen_base	   = SCREEN_BASE;
	current_par.screen_base_p  = 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) {
		/*
		 * RiscPC needs to allocate the DRAM memory
		 * for the framebuffer if we are not using
		 * VRAM.  Archimedes/A5000 machines use a
		 * fixed address for their framebuffers.
		 */
		int order = 0;
		unsigned long page, top;
		while (size > (PAGE_SIZE * (1 << order)))
			order++;
		current_par.screen_base = __get_free_pages(GFP_KERNEL, order);
		if (current_par.screen_base == 0) {
			printk(KERN_ERR "acornfb: unable to allocate screen "
			       "memory\n");
			return -ENOMEM;
		}
		top = current_par.screen_base + (PAGE_SIZE * (1 << order));
		/* Mark the framebuffer pages as reserved so mmap will work. */
		for (page = current_par.screen_base; 
		     page < PAGE_ALIGN(current_par.screen_base + size);
		     page += PAGE_SIZE)
			SetPageReserved(virt_to_page(page));
		/* Hand back any excess pages that we allocated. */
		for (page = current_par.screen_base + size; page < top; page += PAGE_SIZE)
			free_page(page);
		current_par.screen_base_p =
			virt_to_phys((void *)current_par.screen_base);
	}
#endif
#if defined(HAS_VIDC)
	/*
	 * Free unused pages
	 */
	free_unused_pages(PAGE_OFFSET + size, PAGE_OFFSET + MAX_SIZE);
#endif
	
	current_par.screen_size	   = 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(&init_var, &fb_info, NULL, modedb,
				 sizeof(modedb) / sizeof(*modedb),
				 &acornfb_default_mode, DEFAULT_BPP);
		/*
		 * If we found an exact match, all ok.
		 */
		if (rc == 1)
			break;

		rc = fb_find_mode(&init_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(&init_var, &fb_info, NULL, modedb,
				 sizeof(modedb) / sizeof(*modedb),
				 &acornfb_default_mode, DEFAULT_BPP);
		if (rc)
			break;

		rc = fb_find_mode(&init_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 / init_var.pixclock;
	h_sync = h_sync * 512 / (init_var.xres + init_var.left_margin +
		 init_var.right_margin + init_var.hsync_len);
	v_sync = h_sync / (init_var.yres + init_var.upper_margin +
		 init_var.lower_margin + init_var.vsync_len);

	printk(KERN_INFO "Acornfb: %ldkB %cRAM, %s, using %dx%d, "
		"%d.%03dkHz, %dHz\n",
		current_par.screen_size / 1024,
		current_par.using_vram ? 'V' : 'D',
		VIDC_NAME, init_var.xres, init_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 (acornfb_set_var(&init_var, -1, &fb_info))
		printk(KERN_ERR "Acornfb: unable to set display parameters\n");

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

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