[PATCH v2 06/23] drm: sun4i: de3: add format enumeration function to engine

[Ryan Walklin <ryan@testtoast.com>]

From: Jernej Skrabec <jernej.skrabec@gmail.com>

The DE3 display engine supports YUV formats in addition to RGB.

Add an optional format enumeration function to the engine.

Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Ryan Walklin <ryan@testtoast.com>
---
 drivers/gpu/drm/sun4i/sunxi_engine.h | 29 ++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/drivers/gpu/drm/sun4i/sunxi_engine.h b/drivers/gpu/drm/sun4i/sunxi_engine.h
index ec8cf9b2bda41..98a78990fa870 100644
--- a/drivers/gpu/drm/sun4i/sunxi_engine.h
+++ b/drivers/gpu/drm/sun4i/sunxi_engine.h
@@ -120,6 +120,17 @@ struct sunxi_engine_ops {
 	 */
 	void (*mode_set)(struct sunxi_engine *engine,
 			 const struct drm_display_mode *mode);
+
+	/**
+	 * @get_supported_fmts
+	 *
+	 * This callback is used to enumerate all supported output
+	 * formats by the engine. They are used for bridge format
+	 * negotiation.
+	 *
+	 * This function is optional.
+	 */
+	u32 *(*get_supported_fmts)(struct sunxi_engine *engine, u32 *num);
 };
 
 /**
@@ -208,4 +219,22 @@ sunxi_engine_mode_set(struct sunxi_engine *engine,
 	if (engine->ops && engine->ops->mode_set)
 		engine->ops->mode_set(engine, mode);
 }
+
+/**
+ * sunxi_engine_get_supported_formats - Provide array of supported formats
+ * @engine:	pointer to the engine
+ * @num:	pointer to variable, which will hold number of formats
+ *
+ * This list can be used for format negotiation by bridge.
+ */
+static inline u32 *
+sunxi_engine_get_supported_formats(struct sunxi_engine *engine, u32 *num)
+{
+	if (engine->ops && engine->ops->get_supported_fmts)
+		return engine->ops->get_supported_fmts(engine, num);
+
+	*num = 0;
+
+	return NULL;
+}
 #endif /* _SUNXI_ENGINE_H_ */
-- 
2.45.2