drm: rcar-du: Fix DSI enable & disable sequence

The rcar crtc depends on the clock provided from the rcar DSI bridge.
When the DSI bridge is disabled, the clock is stopped, which causes the
crtc disable to timeout.

Also, while I have no issue with the enable, the documentation suggests
to enable the DSI before the crtc so that the crtc has its clock enabled
at enable time. This is also not done by the current driver.

To fix this, we need to keep the DSI bridge enabled until the crtc has
disabled itself, and enable the DSI bridge before crtc enables itself.

Add functions rcar_mipi_dsi_pclk_enable and rcar_mipi_dsi_pclk_disable
to the rcar DSI bridge driver which the rcar driver can use to
enable/disable the DSI clock when needed.  This is similar to what is
already done with the rcar LVDS bridge.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen+renesas@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_drv.h b/drivers/gpu/drm/rcar-du/rcar_du_drv.h
index 712389c7b3d0..5cfa2bb7ad93 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_drv.h
+++ b/drivers/gpu/drm/rcar-du/rcar_du_drv.h
@@ -92,6 +92,7 @@ struct rcar_du_device_info {
 #define RCAR_DU_MAX_GROUPS		DIV_ROUND_UP(RCAR_DU_MAX_CRTCS, 2)
 #define RCAR_DU_MAX_VSPS		4
 #define RCAR_DU_MAX_LVDS		2
+#define RCAR_DU_MAX_DSI			2
 
 struct rcar_du_device {
 	struct device *dev;
@@ -108,6 +109,7 @@ struct rcar_du_device {
 	struct platform_device *cmms[RCAR_DU_MAX_CRTCS];
 	struct rcar_du_vsp vsps[RCAR_DU_MAX_VSPS];
 	struct drm_bridge *lvds[RCAR_DU_MAX_LVDS];
+	struct drm_bridge *dsi[RCAR_DU_MAX_DSI];
 
 	struct {
 		struct drm_property *colorkey;