drm: rcar-du: Remove LVDS and HDMI encoders chaining restriction

The rcar-du driver refuses connecting an LVDS output to an HDMI encoder.
There is not technical reason for that restriction, remove it.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

2 files changed, 15 insertions, 7 deletions

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c
index 7c74ecf2ca67..243aba8d4dd2 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c
@@ -190,13 +190,6 @@ int rcar_du_encoder_init(struct rcar_du_device *rcdu,
         }
 
         if (type == RCAR_DU_ENCODER_HDMI) {
-                if (renc->lvds) {
-                        dev_err(rcdu->dev,
-                                "Chaining LVDS and HDMI encoders not supported\n");
-                        ret = -EINVAL;
-                        goto done;
-                }
-
                 ret = rcar_du_hdmienc_init(rcdu, renc, enc_node);
                 if (ret < 0)
                         goto done;
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_hdmienc.c b/drivers/gpu/drm/rcar-du/rcar_du_hdmienc.c
index 359bc999a9c8..0d774a937e79 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_hdmienc.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_hdmienc.c
@@ -21,6 +21,7 @@
 #include "rcar_du_drv.h"
 #include "rcar_du_encoder.h"
 #include "rcar_du_hdmienc.h"
+#include "rcar_du_lvdsenc.h"
 
 struct rcar_du_hdmienc {
         struct rcar_du_encoder *renc;
@@ -39,9 +40,15 @@ static void rcar_du_hdmienc_dpms(struct drm_encoder *encoder, int mode)
         if (hdmienc->dpms == mode)
                 return;
 
+        if (mode == DRM_MODE_DPMS_ON && hdmienc->renc->lvds)
+                rcar_du_lvdsenc_dpms(hdmienc->renc->lvds, encoder->crtc, mode);
+
         if (sfuncs->dpms)
                 sfuncs->dpms(encoder, mode);
 
+        if (mode != DRM_MODE_DPMS_ON && hdmienc->renc->lvds)
+                rcar_du_lvdsenc_dpms(hdmienc->renc->lvds, encoder->crtc, mode);
+
         hdmienc->dpms = mode;
 }
 
@@ -49,8 +56,16 @@ static bool rcar_du_hdmienc_mode_fixup(struct drm_encoder *encoder,
                                        const struct drm_display_mode *mode,
                                        struct drm_display_mode *adjusted_mode)
 {
+        struct rcar_du_hdmienc *hdmienc = to_rcar_hdmienc(encoder);
         struct drm_encoder_slave_funcs *sfuncs = to_slave_funcs(encoder);
 
+        /* The internal LVDS encoder has a clock frequency operating range of
+         * 30MHz to 150MHz. Clamp the clock accordingly.
+         */
+        if (hdmienc->renc->lvds)
+                adjusted_mode->clock = clamp(adjusted_mode->clock,
+                                             30000, 150000);
+
         if (sfuncs->mode_fixup == NULL)
                 return true;