From: Maxime Ripard <maxime.ripard@free-electrons.com>
Date: Mon, 22 Jan 2018 10:25:16 +0100
Subject: drm/sun4i: backend: Document the engine operations
Git-commit: c4c7c72e5c7aa56e6e8527aea3a79e6242282d8c
Patch-mainline: v4.17-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166
Our operations were missing some documentation to explain what was expected
from them.
Let's make that clearer.
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Link: https://patchwork.freedesktop.org/patch/msgid/fdcd8ec3ae9ecd73ef089ede5218d3a41b49be05.1516613040.git-series.maxime.ripard@free-electrons.com
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
drivers/gpu/drm/sun4i/sunxi_engine.h | 46 +++++++++++++++++++++++++++++++++++
1 file changed, 46 insertions(+)
--- a/drivers/gpu/drm/sun4i/sunxi_engine.h
+++ b/drivers/gpu/drm/sun4i/sunxi_engine.h
@@ -15,12 +15,58 @@ struct drm_device;
struct sunxi_engine;
+/**
+ * struct sunxi_engine_ops - helper operations for sunXi engines
+ *
+ * These hooks are used by the common part of the DRM driver to
+ * implement the proper behaviour.
+ */
struct sunxi_engine_ops {
+ /**
+ * @commit:
+ *
+ * This callback will trigger the hardware switch to commit
+ * the new configuration that has been setup during the next
+ * vblank period.
+ *
+ * This function is optional.
+ */
void (*commit)(struct sunxi_engine *engine);
+
+ /**
+ * @layers_init:
+ *
+ * This callback is used to allocate, initialize and register
+ * the layers supported by that engine.
+ *
+ * This function is mandatory.
+ *
+ * RETURNS:
+ *
+ * The array of struct drm_plane backing the layers, or an
+ * error pointer on failure.
+ */
struct drm_plane **(*layers_init)(struct drm_device *drm,
struct sunxi_engine *engine);
+ /**
+ * @apply_color_correction:
+ *
+ * This callback will enable the color correction in the
+ * engine. This is useful only for the composite output.
+ *
+ * This function is optional.
+ */
void (*apply_color_correction)(struct sunxi_engine *engine);
+
+ /**
+ * @disable_color_correction:
+ *
+ * This callback will stop the color correction in the
+ * engine. This is useful only for the composite output.
+ *
+ * This function is optional.
+ */
void (*disable_color_correction)(struct sunxi_engine *engine);
};