drm/modes: Properly generate a drm_display_mode from a named mode

The framework will get the drm_display_mode from the drm_cmdline_mode it
got by parsing the video command line argument by calling
drm_connector_pick_cmdline_mode().

The heavy lifting will then be done by the
drm_mode_create_from_cmdline_mode() function.

In the case of the named modes though, there's no real code to make that
translation and we rely on the drivers to guess which actual display mode
we meant.

Let's modify drm_mode_create_from_cmdline_mode() to properly generate the
drm_display_mode we mean when passing a named mode.

Reviewed-by: Noralf Trønnes <noralf@tronnes.org>
Tested-by: Mateusz Kwiatkowski <kfyatek+publicgit@gmail.com>
Acked-in-principle-or-something-like-that-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://lore.kernel.org/r/20220728-rpi-analog-tv-properties-v10-9-256dad125326@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>

1 files changed, 28 insertions, 1 deletions

diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
index f9fe065f189b..3d410be8db69 100644
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@@ -2499,6 +2499,31 @@ bool drm_mode_parse_command_line_for_connector(const char *mode_option,
 }
 EXPORT_SYMBOL(drm_mode_parse_command_line_for_connector);
 
+static struct drm_display_mode *drm_named_mode(struct drm_device *dev,
+					       struct drm_cmdline_mode *cmd)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(drm_named_modes); i++) {
+		const struct drm_named_mode *named_mode = &drm_named_modes[i];
+
+		if (strcmp(cmd->name, named_mode->name))
+			continue;
+
+		if (!cmd->tv_mode_specified)
+			continue;
+
+		return drm_analog_tv_mode(dev,
+					  named_mode->tv_mode,
+					  named_mode->pixel_clock_khz * 1000,
+					  named_mode->xres,
+					  named_mode->yres,
+					  named_mode->flags & DRM_MODE_FLAG_INTERLACE);
+	}
+
+	return NULL;
+}
+
 /**
  * drm_mode_create_from_cmdline_mode - convert a command line modeline into a DRM display mode
  * @dev: DRM device to create the new mode for
@@ -2516,7 +2541,9 @@ drm_mode_create_from_cmdline_mode(struct drm_device *dev,
 	if (cmd->xres == 0 || cmd->yres == 0)
 		return NULL;
 
-	if (cmd->cvt)
+	if (strlen(cmd->name))
+		mode = drm_named_mode(dev, cmd);
+	else if (cmd->cvt)
 		mode = drm_cvt_mode(dev,
 				    cmd->xres, cmd->yres,
 				    cmd->refresh_specified ? cmd->refresh : 60,