Commit c7321d6f authored by Guennadi Liakhovetski's avatar Guennadi Liakhovetski Committed by Paul Mundt
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fbdev: sh_mobile_hdmi: add command line option to use the preferred EDID mode 



Currently, if no command-line option is specified, the sh_mobile_hdmi
will use the default 720p video mode. If a command line option of the
form "video=sh_mobile_lcdc:<width>x<height>@<refresh>" is provided,
the driver will look for that mode among those, available in the
monitor EDID. This patch adds the ability to request the driver to
use monitor's preferred mode by specifying 0 as width and hight in
the above string. If that mode is not supported by the system, the
driver will continue scanning through EDID modes, until it finds a
suitable one.

Signed-off-by: default avatarGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent e9ab3207

drivers/video/sh_mobile_hdmi.c

+41 −19
Original line number Diff line number Diff line
@@ -737,7 +737,7 @@ static int sh_hdmi_read_edid(struct sh_hdmi *hdmi, unsigned long *hdmi_rate, 
	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;

	bool scanning = false, preferred_bad = false;

	u8 edid[128];

	char *forced;

	int i;
@@ -800,6 +800,9 @@ static int sh_hdmi_read_edid(struct sh_hdmi *hdmi, unsigned long *hdmi_rate, 
		if (i < 2) {

			f_width = 0;

			f_height = 0;

		} else {

			/* The user wants us to use the EDID data */

			scanning = true;

		}

		dev_dbg(hdmi->dev, "Forced mode %ux%u@%uHz\n",

			f_width, f_height, f_refresh);
@@ -807,37 +810,56 @@ static int sh_hdmi_read_edid(struct sh_hdmi *hdmi, unsigned long *hdmi_rate, 


	/* 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 < hdmi->monspec.modedb_len && scanning;

	     i++, mode++) {

		unsigned long rate_error;



		if (!f_width && !f_height) {

			/*

			 * A parameter string "video=sh_mobile_lcdc:0x0" means

			 * use the preferred EDID mode. If it is rejected by

			 * .fb_check_var(), keep looking, until an acceptable

			 * one is found.

			 */

			if ((mode->flag & FB_MODE_IS_FIRST) || preferred_bad)

				scanning = false;

			else

				continue;

		} else if (f_width != mode->xres || f_height != mode->yres) {

			/* No interest in unmatching modes */

		if (f_width != mode->xres || f_height != mode->yres)

			continue;

		}



		rate_error = sh_hdmi_rate_error(hdmi, mode, hdmi_rate, parent_rate);



		if (scanning) {

			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 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;

				scanning = false;

			else if (found && found_rate_error <= rate_error)

				/*

			 * 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

				 * 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);



		var->bits_per_pixel = info->var.bits_per_pixel;



		if (info && info->fbops->fb_check_var &&

		    info->fbops->fb_check_var(var, info)) {

			exact_match = false;

			scanning = true;

			preferred_bad = true;

			continue;

		}

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