drm: simple_kms_helper: Add mode_valid() callback support

The PL111 needs to filter valid modes based on memory bandwidth.
I guess it is a pretty simple operation, so we can still claim
the DRM KMS helper pipeline is simple after adding this (optional)
vtable callback.

Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180220072859.3386-1-linus.walleij@linaro.org

diff --git a/drivers/gpu/drm/drm_simple_kms_helper.c b/drivers/gpu/drm/drm_simple_kms_helper.c
index 9d3f6b70812cd100c8783cf58a8abe09d68c77ba..6c327fdbaaee546729d8f05685278ec188350990 100644 (file)
--- a/drivers/gpu/drm/drm_simple_kms_helper.c
+++ b/drivers/gpu/drm/drm_simple_kms_helper.c
@@ -34,6 +34,20 @@ static const struct drm_encoder_funcs drm_simple_kms_encoder_funcs = {
        .destroy = drm_encoder_cleanup,
 };
 
+static enum drm_mode_status
+drm_simple_kms_crtc_mode_valid(struct drm_crtc *crtc,
+                              const struct drm_display_mode *mode)
+{
+       struct drm_simple_display_pipe *pipe;
+
+       pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
+       if (!pipe->funcs || !pipe->funcs->mode_valid)
+               /* Anything goes */
+               return MODE_OK;
+
+       return pipe->funcs->mode_valid(crtc, mode);
+}
+
 static int drm_simple_kms_crtc_check(struct drm_crtc *crtc,
                                     struct drm_crtc_state *state)
 {
@@ -72,6 +86,7 @@ static void drm_simple_kms_crtc_disable(struct drm_crtc *crtc,
 }
 
 static const struct drm_crtc_helper_funcs drm_simple_kms_crtc_helper_funcs = {
+       .mode_valid = drm_simple_kms_crtc_mode_valid,
        .atomic_check = drm_simple_kms_crtc_check,
        .atomic_enable = drm_simple_kms_crtc_enable,
        .atomic_disable = drm_simple_kms_crtc_disable,

diff --git a/include/drm/drm_simple_kms_helper.h b/include/drm/drm_simple_kms_helper.h
index 6d9adbb46293310cb09780ec509f048b94642a41..d9e4c3c3f0094015c6b8e882109e603225399cec 100644 (file)
--- a/include/drm/drm_simple_kms_helper.h
+++ b/include/drm/drm_simple_kms_helper.h
@@ -21,6 +21,20 @@ struct drm_simple_display_pipe;
  *                                        display pipeline
  */
 struct drm_simple_display_pipe_funcs {
+       /**
+        * @mode_valid:
+        *
+        * This function is called to filter out valid modes from the
+        * suggestions suggested by the bridge or display. This optional
+        * hook is passed in when initializing the pipeline.
+        *
+        * RETURNS:
+        *
+        * drm_mode_status Enum
+        */
+       enum drm_mode_status (*mode_valid)(struct drm_crtc *crtc,
+                                          const struct drm_display_mode *mode);
+
        /**
         * @enable:
         *