[PATCH v21 21/25] drm/mediatek: add dma dev get function

["Nancy.Lin" <nancy.lin@xxxxxxxxxxxx>]

This is a preparation for adding support for the ovl_adaptor sub driver
Ovl_adaptor is a DRM sub driver, which doesn't have dma dev. Add
dma_dev_get function for getting representative dma dev in ovl_adaptor.

Signed-off-by: Nancy.Lin <nancy.lin@xxxxxxxxxxxx>
Reviewed-by: AngeloGioachino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
Reviewed-by: CK Hu <ck.hu@xxxxxxxxxxxx>
---
 drivers/gpu/drm/mediatek/mtk_drm_crtc.c     | 15 +++++++++++++++
 drivers/gpu/drm/mediatek/mtk_drm_crtc.h     |  1 +
 drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h |  8 ++++++++
 3 files changed, 24 insertions(+)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
index f24b21eb03cd..5c2c21958325 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
@@ -59,6 +59,7 @@ struct mtk_drm_crtc {
 #endif
 
 	struct device			*mmsys_dev;
+	struct device			*dma_dev;
 	struct mtk_mutex		*mutex;
 	unsigned int			ddp_comp_nr;
 	struct mtk_ddp_comp		**ddp_comp;
@@ -865,6 +866,13 @@ static int mtk_drm_crtc_init_comp_planes(struct drm_device *drm_dev,
 	return 0;
 }
 
+struct device *mtk_drm_crtc_dma_dev_get(struct drm_crtc *crtc)
+{
+	struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
+
+	return mtk_crtc->dma_dev;
+}
+
 int mtk_drm_crtc_create(struct drm_device *drm_dev,
 			const enum mtk_ddp_comp_id *path, unsigned int path_len)
 {
@@ -953,6 +961,13 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
 			return ret;
 	}
 
+	/*
+	 * Default to use the first component as the dma dev.
+	 * In the case of ovl_adaptor sub driver, it needs to use the
+	 * dma_dev_get function to get representative dma dev.
+	 */
+	mtk_crtc->dma_dev = mtk_ddp_comp_dma_dev_get(&priv->ddp_comp[path[0]]);
+
 	ret = mtk_drm_crtc_init(drm_dev, mtk_crtc, pipe);
 	if (ret < 0)
 		return ret;
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.h b/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
index cb9a36c48d4f..f5a6e80c5265 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
+++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
@@ -22,5 +22,6 @@ int mtk_drm_crtc_plane_check(struct drm_crtc *crtc, struct drm_plane *plane,
 			     struct mtk_plane_state *state);
 void mtk_drm_crtc_async_update(struct drm_crtc *crtc, struct drm_plane *plane,
 			       struct drm_atomic_state *plane_state);
+struct device *mtk_drm_crtc_dma_dev_get(struct drm_crtc *crtc);
 
 #endif /* MTK_DRM_CRTC_H */
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
index a43d82c12a9a..b04e656cb251 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
+++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
@@ -70,6 +70,7 @@ struct mtk_ddp_comp_funcs {
 	void (*bgclr_in_off)(struct device *dev);
 	void (*ctm_set)(struct device *dev,
 			struct drm_crtc_state *state);
+	struct device * (*dma_dev_get)(struct device *dev);
 };
 
 struct mtk_ddp_comp {
@@ -202,6 +203,13 @@ static inline void mtk_ddp_ctm_set(struct mtk_ddp_comp *comp,
 		comp->funcs->ctm_set(comp->dev, state);
 }
 
+static inline struct device *mtk_ddp_comp_dma_dev_get(struct mtk_ddp_comp *comp)
+{
+	if (comp->funcs && comp->funcs->dma_dev_get)
+		return comp->funcs->dma_dev_get(comp->dev);
+	return comp->dev;
+}
+
 int mtk_ddp_comp_get_id(struct device_node *node,
 			enum mtk_ddp_comp_type comp_type);
 unsigned int mtk_drm_find_possible_crtc_by_comp(struct drm_device *drm,
-- 
2.18.0