panel: Lightweight support of get_modes()

Linux uses get_modes() to fetch all available panel modes from the
driver. This is also used to fetch the modes from Linux's simple panel
implementation where a list of drm_display_mode structs is used to
define the different possible panels.

To make our work easier, create a compatible way of fetching and
defining these modes in u-boot. get_modes() fetches the available modes
from the panel driver. The get_display_timing() call maps the
drm_display_mode properties to the display_timing struct. This call now
uses whatever panel operation is available, get_display_timing() or
get_modes().

Reviewed-by: Fabio Estevam <[email protected]>
Signed-off-by: Markus Schneider-Pargmann (TI.com) <[email protected]>

1 files changed, 35 insertions, 3 deletions

diff --git a/drivers/video/panel-uclass.c b/drivers/video/panel-uclass.c
index 52a3466dc8c..82e8339dde1 100644
--- a/drivers/video/panel-uclass.c
+++ b/drivers/video/panel-uclass.c
@@ -37,15 +37,47 @@ int panel_set_backlight(struct udevice *dev, int percent)
 	return ops->set_backlight(dev, percent);
 }
 
+static void drm_mode_to_display_timing(const struct drm_display_mode *mode,
+				       struct display_timing *timing)
+{
+	timing->pixelclock.typ = mode->clock * 1000; /* kHz to Hz */
+	timing->hactive.typ = mode->hdisplay;
+	timing->hfront_porch.typ = mode->hsync_start - mode->hdisplay;
+	timing->hsync_len.typ = mode->hsync_end - mode->hsync_start;
+	timing->hback_porch.typ = mode->htotal - mode->hsync_end;
+	timing->vactive.typ = mode->vdisplay;
+	timing->vfront_porch.typ = mode->vsync_start - mode->vdisplay;
+	timing->vsync_len.typ = mode->vsync_end - mode->vsync_start;
+	timing->vback_porch.typ = mode->vtotal - mode->vsync_end;
+
+	/* DRM_MODE_FLAG_* defines are already mapped to u-boot DISPLAY_FLAGS */
+	timing->flags = mode->flags;
+}
+
 int panel_get_display_timing(struct udevice *dev,
 			     struct display_timing *timings)
 {
 	struct panel_ops *ops = panel_get_ops(dev);
+	const struct drm_display_mode *modes;
+	int ret = -ENOSYS;
 
-	if (!ops->get_display_timing)
-		return -ENOSYS;
+	if (ops->get_display_timing) {
+		ret = ops->get_display_timing(dev, timings);
+		if (ret != -ENODEV)
+			return ret;
+	}
+
+	if (!ops->get_modes)
+		return ret;
+
+	ret = ops->get_modes(dev, &modes);
+	if (ret < 0)
+		return ret;
+	else if (ret == 0)
+		return -ENODEV;
 
-	return ops->get_display_timing(dev, timings);
+	drm_mode_to_display_timing(&modes[0], timings);
+	return 0;
 }
 
 UCLASS_DRIVER(panel) = {