video, sm501: add edid and commandline support

- add commandline options:
  sm501fb.mode:
    Specify resolution as "<xres>x<yres>[-<bpp>][@<refresh>]"
  sm501fb.bpp:
    Specify bit-per-pixel if not specified mode

- Add support for encoding display mode information
  in the device tree using verbatim EDID block.

  If the "edid" entry in the "smi,sm501" node is present,
  the driver will build mode database using EDID data
  and allow setting the display modes from this database.

Signed-off-by: Heiko Schocher <hs@denx.de>
cc: linux-fbdev@vger.kernel.org
cc: devicetree-discuss@ozlabs.org
cc: Ben Dooks <ben@simtec.co.uk>
cc: Vincent Sanders <vince@simtec.co.uk>
cc: Samuel Ortiz <sameo@linux.intel.com>
cc: linux-kernel@vger.kernel.org
cc: Randy Dunlap <rdunlap@xenotime.net>
cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/drivers/video/sm501fb.c b/drivers/video/sm501fb.c
index 5df406c..f31252c 100644
--- a/drivers/video/sm501fb.c
+++ b/drivers/video/sm501fb.c
@@ -41,6 +41,26 @@
 #include <linux/sm501.h>
 #include <linux/sm501-regs.h>
 
+#include "edid.h"
+
+static char *fb_mode = "640x480-16@60";
+static unsigned long default_bpp = 16;
+
+static struct fb_videomode __devinitdata sm501_default_mode = {
+	.refresh	= 60,
+	.xres		= 640,
+	.yres		= 480,
+	.pixclock	= 20833,
+	.left_margin	= 142,
+	.right_margin	= 13,
+	.upper_margin	= 21,
+	.lower_margin	= 1,
+	.hsync_len	= 69,
+	.vsync_len	= 3,
+	.sync		= FB_SYNC_HOR_HIGH_ACT | FB_SYNC_VERT_HIGH_ACT,
+	.vmode		= FB_VMODE_NONINTERLACED
+};
+
 #define NR_PALETTE	256
 
 enum sm501_controller {
@@ -77,6 +97,7 @@
 	void __iomem		*regs2d;	/* 2d remapped registers */
 	void __iomem		*fbmem;		/* remapped framebuffer */
 	size_t			 fbmem_len;	/* length of remapped region */
+	u8 *edid_data;
 };
 
 /* per-framebuffer private data */
@@ -1725,9 +1746,16 @@
 	fb->var.vmode		= FB_VMODE_NONINTERLACED;
 	fb->var.bits_per_pixel  = 16;
 
+	if (info->edid_data) {
+			/* Now build modedb from EDID */
+			fb_edid_to_monspecs(info->edid_data, &fb->monspecs);
+			fb_videomode_to_modelist(fb->monspecs.modedb,
+						 fb->monspecs.modedb_len,
+						 &fb->modelist);
+	}
+
 	if (enable && (pd->flags & SM501FB_FLAG_USE_INIT_MODE) && 0) {
 		/* TODO read the mode from the current display */
-
 	} else {
 		if (pd->def_mode) {
 			dev_info(info->dev, "using supplied mode\n");
@@ -1737,12 +1765,34 @@
 			fb->var.xres_virtual = fb->var.xres;
 			fb->var.yres_virtual = fb->var.yres;
 		} else {
-			ret = fb_find_mode(&fb->var, fb,
+			if (info->edid_data)
+				ret = fb_find_mode(&fb->var, fb, fb_mode,
+					fb->monspecs.modedb,
+					fb->monspecs.modedb_len,
+					&sm501_default_mode, default_bpp);
+			else
+				ret = fb_find_mode(&fb->var, fb,
 					   NULL, NULL, 0, NULL, 8);
 
-			if (ret == 0 || ret == 4) {
-				dev_err(info->dev,
-					"failed to get initial mode\n");
+			switch (ret) {
+			case 1:
+				dev_info(info->dev, "using mode specified in "
+						"@mode\n");
+				break;
+			case 2:
+				dev_info(info->dev, "using mode specified in "
+					"@mode with ignored refresh rate\n");
+				break;
+			case 3:
+				dev_info(info->dev, "using mode default "
+					"mode\n");
+				break;
+			case 4:
+				dev_info(info->dev, "using mode from list\n");
+				break;
+			default:
+				dev_info(info->dev, "ret = %d\n", ret);
+				dev_info(info->dev, "failed to find mode\n");
 				return -EINVAL;
 			}
 		}
@@ -2157,6 +2207,11 @@
 module_init(sm501fb_init);
 module_exit(sm501fb_cleanup);
 
+module_param_named(mode, fb_mode, charp, 0);
+MODULE_PARM_DESC(mode,
+	"Specify resolution as \"<xres>x<yres>[-<bpp>][@<refresh>]\" ");
+module_param_named(bpp, default_bpp, ulong, 0);
+MODULE_PARM_DESC(bpp, "Specify bit-per-pixel if not specified mode");
 MODULE_AUTHOR("Ben Dooks, Vincent Sanders");
 MODULE_DESCRIPTION("SM501 Framebuffer driver");
 MODULE_LICENSE("GPL v2");