drm/exynos: add display-mode-check operation to exynos_mixer_ops struct

This patch adds the display mode check operation to exynos_mixer_ops
in drm-common-hdmi. In Exynos SoCs, mixer IP can put certain restrictions
on the proposed display modes. These restriction needs to be considered
during mode negotiation, which happens immediately after edid parsing.

Both, mixer check-mode and hdmi check-timing callbacks are called one after
another and ANDed result is returned back.

Signed-off-by: Rahul Sharma <rahul.sharma@samsung.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/drivers/gpu/drm/exynos/exynos_drm_hdmi.c b/drivers/gpu/drm/exynos/exynos_drm_hdmi.c
index 28644539b305..7c27df03c9ff 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_hdmi.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_hdmi.c
@@ -124,9 +124,21 @@ static struct edid *drm_hdmi_get_edid(struct device *dev,
 static int drm_hdmi_check_timing(struct device *dev, void *timing)
 {
         struct drm_hdmi_context *ctx = to_context(dev);
+        int ret = 0;
 
         DRM_DEBUG_KMS("%s\n", __FILE__);
 
+        /*
+        * Both, mixer and hdmi should be able to handle the requested mode.
+        * If any of the two fails, return mode as BAD.
+        */
+
+        if (mixer_ops && mixer_ops->check_timing)
+                ret = mixer_ops->check_timing(ctx->mixer_ctx->ctx, timing);
+
+        if (ret)
+                return ret;
+
         if (hdmi_ops && hdmi_ops->check_timing)
                 return hdmi_ops->check_timing(ctx->hdmi_ctx->ctx, timing);