1 files changed, 88 insertions, 50 deletions

diff --git a/drivers/video/sh_mobile_hdmi.c b/drivers/video/sh_mobile_hdmi.c
index 94a94fde2c67..f0ff2848700c 100644
--- a/drivers/video/sh_mobile_hdmi.c
+++ b/drivers/video/sh_mobile_hdmi.c
@@ -611,14 +611,39 @@ static void sh_hdmi_configure(struct sh_hdmi *hdmi)
 	hdmi_write(hdmi, 0x40, HDMI_SYSTEM_CTRL);
 }
 
+static unsigned long sh_hdmi_rate_error(struct sh_hdmi *hdmi,
+					const struct fb_videomode *mode)
+{
+	long target = PICOS2KHZ(mode->pixclock) * 1000,
+		rate = clk_round_rate(hdmi->hdmi_clk, target);
+	unsigned long rate_error = rate > 0 ? abs(rate - target) : ULONG_MAX;
+
+	dev_dbg(hdmi->dev, "%u-%u-%u-%u x %u-%u-%u-%u\n",
+		mode->left_margin, mode->xres,
+		mode->right_margin, mode->hsync_len,
+		mode->upper_margin, mode->yres,
+		mode->lower_margin, mode->vsync_len);
+
+	dev_dbg(hdmi->dev, "\t@%lu(+/-%lu)Hz, e=%lu / 1000, r=%uHz\n", target,
+		 rate_error, rate_error ? 10000 / (10 * target / rate_error) : 0,
+		 mode->refresh);
+
+	return rate_error;
+}
+
 static int sh_hdmi_read_edid(struct sh_hdmi *hdmi)
 {
 	struct fb_var_screeninfo tmpvar;
-	/* TODO: When we are ready to use EDID, use this to fill &hdmi->var */
 	struct fb_var_screeninfo *var = &tmpvar;
 	const struct fb_videomode *mode, *found = NULL;
-	int i;
+	struct fb_info *info = hdmi->info;
+	struct fb_modelist *modelist = NULL;
+	unsigned int f_width = 0, f_height = 0, f_refresh = 0;
+	unsigned long found_rate_error = ULONG_MAX; /* silly compiler... */
+	bool exact_match = false;
 	u8 edid[128];
+	char *forced;
+	int i;
 
 	/* Read EDID */
 	dev_dbg(hdmi->dev, "Read back EDID code:");
@@ -639,69 +664,82 @@ static int sh_hdmi_read_edid(struct sh_hdmi *hdmi)
 
 	fb_edid_to_monspecs(edid, &hdmi->monspec);
 
-	/* First look for an exact match */
-	for (i = 0, mode = hdmi->monspec.modedb; i < hdmi->monspec.modedb_len;
+	fb_get_options("sh_mobile_lcdc", &forced);
+	if (forced && *forced) {
+		/* Only primitive parsing so far */
+		i = sscanf(forced, "%ux%u@%u",
+			   &f_width, &f_height, &f_refresh);
+		if (i < 2) {
+			f_width = 0;
+			f_height = 0;
+		}
+		dev_dbg(hdmi->dev, "Forced mode %ux%u@%uHz\n",
+			f_width, f_height, f_refresh);
+	}
+
+	/* Walk monitor modes to find the best or the exact match */
+	for (i = 0, mode = hdmi->monspec.modedb;
+	     f_width && f_height && i < hdmi->monspec.modedb_len && !exact_match;
 	     i++, mode++) {
-		dev_dbg(hdmi->dev, "%u-%u-%u-%u x %u-%u-%u-%u @ %lu kHz monitor detected\n",
-			mode->left_margin, mode->xres,
-			mode->right_margin, mode->hsync_len,
-			mode->upper_margin, mode->yres,
-			mode->lower_margin, mode->vsync_len,
-			PICOS2KHZ(mode->pixclock));
-		if (!found && hdmi->info) {
-			fb_videomode_to_var(var, mode);
-			found = fb_match_mode(var, &hdmi->info->modelist);
+		unsigned long rate_error = sh_hdmi_rate_error(hdmi, mode);
+
+		/* No interest in unmatching modes */
+		if (f_width != mode->xres || f_height != mode->yres)
+			continue;
+		if (f_refresh == mode->refresh || (!f_refresh && !rate_error))
+			/*
+			 * Exact match if either the refresh rate matches or it
+			 * hasn't been specified and we've found a mode, for
+			 * which we can configure the clock precisely
+			 */
+			exact_match = true;
+		else if (found && found_rate_error <= rate_error)
 			/*
-			 * If an exact match found, we're good to bail out, but
-			 * continue to print out all modes
+			 * We otherwise search for the closest matching clock
+			 * rate - either if no refresh rate has been specified
+			 * or we cannot find an exactly matching one
 			 */
+			continue;
+
+		/* Check if supported: sufficient fb memory, supported clock-rate */
+		fb_videomode_to_var(var, mode);
+
+		if (info && info->fbops->fb_check_var &&
+		    info->fbops->fb_check_var(var, info)) {
+			exact_match = false;
+			continue;
 		}
+
+		found = mode;
+		found_rate_error = rate_error;
 	}
 
 	/*
-	 * The monitor might also work with a mode, that is smaller, than one of
-	 * its modes, use the first (default) one for this
+	 * TODO 1: if no ->info is present, postpone running the config until
+	 * after ->info first gets registered.
+	 * TODO 2: consider registering the HDMI platform device from the LCDC
+	 * driver, and passing ->info with HDMI platform data.
 	 */
-	if (!found && hdmi->info && hdmi->monspec.modedb_len) {
-		struct fb_modelist *modelist;
-		unsigned int min_err = UINT_MAX, err;
-		const struct fb_videomode *mon_mode = hdmi->monspec.modedb;
-
-		list_for_each_entry(modelist, &hdmi->info->modelist, list) {
-			mode = &modelist->mode;
-			dev_dbg(hdmi->dev, "matching %ux%u to %ux%u\n", mode->xres, mode->yres,
-				 mon_mode->xres, mon_mode->yres);
-			if (mode->xres <= mon_mode->xres && mode->yres <= mon_mode->yres) {
-				err = mon_mode->xres - mode->xres + mon_mode->yres - mode->yres;
-				if (!err) {
-					found = mode;
-					break;
-				}
-				if (err < min_err) {
-					found = mode;
-					min_err = err;
-				}
-			}
+	if (info && !found) {
+		modelist = hdmi->info->modelist.next &&
+			!list_empty(&hdmi->info->modelist) ?
+			list_entry(hdmi->info->modelist.next,
+				   struct fb_modelist, list) :
+			NULL;
+
+		if (modelist) {
+			found = &modelist->mode;
+			found_rate_error = sh_hdmi_rate_error(hdmi, found);
 		}
 	}
 
-	/* Nothing suitable specified by the platform: use monitor's first mode */
-	if (!found && hdmi->monspec.modedb_len)
-		found = hdmi->monspec.modedb;
-
-	/* No valid timing info in EDID - last resort: use platform default mode */
-	if (!found && hdmi->info) {
-		struct fb_modelist *modelist = list_entry(hdmi->info->modelist.next,
-							  struct fb_modelist, list);
-		found = &modelist->mode;
-	}
-
 	/* No cookie today */
 	if (!found)
 		return -ENXIO;
 
-	dev_dbg(hdmi->dev, "best \"%s\" %ux%u@%ups\n", found->name,
-		found->xres, found->yres, found->pixclock);
+	dev_info(hdmi->dev, "Using %s mode %ux%u@%uHz (%luHz), clock error %luHz\n",
+		 modelist ? "default" : "EDID", found->xres, found->yres,
+		 found->refresh, PICOS2KHZ(found->pixclock) * 1000, found_rate_error);
 
 	if ((found->xres == 720 && found->yres == 480) ||
 	    (found->xres == 1280 && found->yres == 720) ||