[PATCH 05/10] drm/sun4i: Explicitly list and check formats supported by the frontend

[Paul Kocialkowski]

In order to check whether the frontend supports a specific format, an
explicit list and a related helper are introduced.

They are then used to determine whether the frontend can actually support
the requested format when it was selected to be used.

Signed-off-by: Paul Kocialkowski <paul.kocialkowski@xxxxxxxxxxx>
---
 drivers/gpu/drm/sun4i/sun4i_backend.c  |  5 ++++
 drivers/gpu/drm/sun4i/sun4i_frontend.c | 44 ++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/sun4i/sun4i_frontend.h |  1 +
 3 files changed, 50 insertions(+)

diff --git a/drivers/gpu/drm/sun4i/sun4i_backend.c b/drivers/gpu/drm/sun4i/sun4i_backend.c
index 7703ba989743..1fad0714c70e 100644
--- a/drivers/gpu/drm/sun4i/sun4i_backend.c
+++ b/drivers/gpu/drm/sun4i/sun4i_backend.c
@@ -532,6 +532,11 @@ static int sun4i_backend_atomic_check(struct sunxi_engine *engine,
 		struct drm_format_name_buf format_name;
 
 		if (sun4i_backend_plane_uses_frontend(plane_state)) {
+			if (!sun4i_frontend_format_is_supported(fb->format->format)) {
+				DRM_DEBUG_DRIVER("Frontend plane check failed\n");
+				return -EINVAL;
+			}
+
 			DRM_DEBUG_DRIVER("Using the frontend for plane %d\n",
 					 plane->index);
 
diff --git a/drivers/gpu/drm/sun4i/sun4i_frontend.c b/drivers/gpu/drm/sun4i/sun4i_frontend.c
index 3ea925584891..2dc33383be22 100644
--- a/drivers/gpu/drm/sun4i/sun4i_frontend.c
+++ b/drivers/gpu/drm/sun4i/sun4i_frontend.c
@@ -128,6 +128,50 @@ static int sun4i_frontend_drm_format_to_output_fmt(uint32_t fmt, u32 *val)
 	}
 }
 
+static const uint32_t sun4i_frontend_formats[] = {
+	/* RGB */
+	DRM_FORMAT_XRGB8888,
+	DRM_FORMAT_BGRX8888,
+	/* YUV444 */
+	DRM_FORMAT_YUV444,
+	DRM_FORMAT_YVU444,
+	/* YUV422 */
+	DRM_FORMAT_YUYV,
+	DRM_FORMAT_YVYU,
+	DRM_FORMAT_UYVY,
+	DRM_FORMAT_VYUY,
+	DRM_FORMAT_NV16,
+	DRM_FORMAT_NV61,
+	DRM_FORMAT_YUV422,
+	DRM_FORMAT_YVU422,
+	/* YUV420 */
+	DRM_FORMAT_NV12,
+	DRM_FORMAT_NV21,
+	DRM_FORMAT_YUV420,
+	DRM_FORMAT_YVU420,
+	/* YUV411 */
+	DRM_FORMAT_YUV411,
+	DRM_FORMAT_YVU411,
+};
+
+bool sun4i_frontend_format_is_supported(uint32_t fmt)
+{
+	bool found = false;
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(sun4i_frontend_formats); i++) {
+		if (sun4i_frontend_formats[i] == fmt) {
+			found = true;
+			break;
+		}
+	}
+
+	if (!found)
+		return false;
+
+	return true;
+}
+
 int sun4i_frontend_update_formats(struct sun4i_frontend *frontend,
 				  struct drm_plane *plane, uint32_t out_fmt)
 {
diff --git a/drivers/gpu/drm/sun4i/sun4i_frontend.h b/drivers/gpu/drm/sun4i/sun4i_frontend.h
index 02661ce81f3e..a9cb908ced16 100644
--- a/drivers/gpu/drm/sun4i/sun4i_frontend.h
+++ b/drivers/gpu/drm/sun4i/sun4i_frontend.h
@@ -95,5 +95,6 @@ void sun4i_frontend_update_coord(struct sun4i_frontend *frontend,
 				 struct drm_plane *plane);
 int sun4i_frontend_update_formats(struct sun4i_frontend *frontend,
 				  struct drm_plane *plane, uint32_t out_fmt);
+bool sun4i_frontend_format_is_supported(uint32_t fmt);
 
 #endif /* _SUN4I_FRONTEND_H_ */
-- 
2.16.2