media: v4l2-mem2mem: Correct return type for mem2mem buffer helpers

This commit changes the return type of mem2mem buffer handling API.
Namely, these functions:

 v4l2_m2m_next_buf
 v4l2_m2m_last_buf
 v4l2_m2m_buf_remove
 v4l2_m2m_next_src_buf
 v4l2_m2m_next_dst_buf
 v4l2_m2m_last_src_buf
 v4l2_m2m_last_dst_buf
 v4l2_m2m_src_buf_remove
 v4l2_m2m_dst_buf_remove

which currently return void pointer.

In every case, the actual return type is a struct vb2_v4l2_buffer
pointer. Change the return type of the listed functions,
so type checking can be properly used.

Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
[hverkuil-cisco@xs4all.nl: clean up line-too-long checkpatch warnings]
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
diff --git a/include/media/v4l2-mem2mem.h b/include/media/v4l2-mem2mem.h
index 47c6d9a..bb3e63d 100644
--- a/include/media/v4l2-mem2mem.h
+++ b/include/media/v4l2-mem2mem.h
@@ -425,7 +425,7 @@ unsigned int v4l2_m2m_num_dst_bufs_ready(struct v4l2_m2m_ctx *m2m_ctx)
  *
  * @q_ctx: pointer to struct @v4l2_m2m_queue_ctx
  */
-void *v4l2_m2m_next_buf(struct v4l2_m2m_queue_ctx *q_ctx);
+struct vb2_v4l2_buffer *v4l2_m2m_next_buf(struct v4l2_m2m_queue_ctx *q_ctx);
 
 /**
  * v4l2_m2m_next_src_buf() - return next source buffer from the list of ready
@@ -433,7 +433,8 @@ void *v4l2_m2m_next_buf(struct v4l2_m2m_queue_ctx *q_ctx);
  *
  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
  */
-static inline void *v4l2_m2m_next_src_buf(struct v4l2_m2m_ctx *m2m_ctx)
+static inline struct vb2_v4l2_buffer *
+v4l2_m2m_next_src_buf(struct v4l2_m2m_ctx *m2m_ctx)
 {
 	return v4l2_m2m_next_buf(&m2m_ctx->out_q_ctx);
 }
@@ -444,7 +445,8 @@ static inline void *v4l2_m2m_next_src_buf(struct v4l2_m2m_ctx *m2m_ctx)
  *
  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
  */
-static inline void *v4l2_m2m_next_dst_buf(struct v4l2_m2m_ctx *m2m_ctx)
+static inline struct vb2_v4l2_buffer *
+v4l2_m2m_next_dst_buf(struct v4l2_m2m_ctx *m2m_ctx)
 {
 	return v4l2_m2m_next_buf(&m2m_ctx->cap_q_ctx);
 }
@@ -454,7 +456,7 @@ static inline void *v4l2_m2m_next_dst_buf(struct v4l2_m2m_ctx *m2m_ctx)
  *
  * @q_ctx: pointer to struct @v4l2_m2m_queue_ctx
  */
-void *v4l2_m2m_last_buf(struct v4l2_m2m_queue_ctx *q_ctx);
+struct vb2_v4l2_buffer *v4l2_m2m_last_buf(struct v4l2_m2m_queue_ctx *q_ctx);
 
 /**
  * v4l2_m2m_last_src_buf() - return last destination buffer from the list of
@@ -462,7 +464,8 @@ void *v4l2_m2m_last_buf(struct v4l2_m2m_queue_ctx *q_ctx);
  *
  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
  */
-static inline void *v4l2_m2m_last_src_buf(struct v4l2_m2m_ctx *m2m_ctx)
+static inline struct vb2_v4l2_buffer *
+v4l2_m2m_last_src_buf(struct v4l2_m2m_ctx *m2m_ctx)
 {
 	return v4l2_m2m_last_buf(&m2m_ctx->out_q_ctx);
 }
@@ -473,7 +476,8 @@ static inline void *v4l2_m2m_last_src_buf(struct v4l2_m2m_ctx *m2m_ctx)
  *
  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
  */
-static inline void *v4l2_m2m_last_dst_buf(struct v4l2_m2m_ctx *m2m_ctx)
+static inline struct vb2_v4l2_buffer *
+v4l2_m2m_last_dst_buf(struct v4l2_m2m_ctx *m2m_ctx)
 {
 	return v4l2_m2m_last_buf(&m2m_ctx->cap_q_ctx);
 }
@@ -547,7 +551,7 @@ struct vb2_queue *v4l2_m2m_get_dst_vq(struct v4l2_m2m_ctx *m2m_ctx)
  *
  * @q_ctx: pointer to struct @v4l2_m2m_queue_ctx
  */
-void *v4l2_m2m_buf_remove(struct v4l2_m2m_queue_ctx *q_ctx);
+struct vb2_v4l2_buffer *v4l2_m2m_buf_remove(struct v4l2_m2m_queue_ctx *q_ctx);
 
 /**
  * v4l2_m2m_src_buf_remove() - take off a source buffer from the list of ready
@@ -555,7 +559,8 @@ void *v4l2_m2m_buf_remove(struct v4l2_m2m_queue_ctx *q_ctx);
  *
  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
  */
-static inline void *v4l2_m2m_src_buf_remove(struct v4l2_m2m_ctx *m2m_ctx)
+static inline struct vb2_v4l2_buffer *
+v4l2_m2m_src_buf_remove(struct v4l2_m2m_ctx *m2m_ctx)
 {
 	return v4l2_m2m_buf_remove(&m2m_ctx->out_q_ctx);
 }
@@ -566,7 +571,8 @@ static inline void *v4l2_m2m_src_buf_remove(struct v4l2_m2m_ctx *m2m_ctx)
  *
  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
  */
-static inline void *v4l2_m2m_dst_buf_remove(struct v4l2_m2m_ctx *m2m_ctx)
+static inline struct vb2_v4l2_buffer *
+v4l2_m2m_dst_buf_remove(struct v4l2_m2m_ctx *m2m_ctx)
 {
 	return v4l2_m2m_buf_remove(&m2m_ctx->cap_q_ctx);
 }