[PATCH v14 03/11] media: uvcvideo: introduce __uvc_ctrl_get_std()

[Yunke Cao <yunkec@google.com>]

Refactor uvc_ctrl to make adding compound control easier.

Currently __uvc_ctrl_get() only work for non-compound controls.
Move the logic into __uvc_ctrl_std(), return error for compound
controls.

Make __uvc_ctrl_get() call __uvc_ctrl_std() inside. Also modify some of the
callers of __uvc_ctrl_get() to call __uvc_ctrl_get_std() instead.

Signed-off-by: Yunke Cao <yunkec@google.com>
---
Changelog since v12:
- No change.
Changelog since v11:
- Minor change to avoid negative if statement.
Changelog since v10:
- Better commit message.
Changelog since v9:
- No change.
Changelog since v8:
- No change.
Changelog since v7:
- Newly added patch. Split the refactoring of uvc_ctrl_get from v7 3/7.

 drivers/media/usb/uvc/uvc_ctrl.c | 42 +++++++++++++++++++++-----------
 1 file changed, 28 insertions(+), 14 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index 8d8333786333..4a685532f7eb 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -1081,15 +1081,15 @@ static int __uvc_ctrl_load_cur(struct uvc_video_chain *chain,
 	return ret;
 }
 
-static int __uvc_ctrl_get(struct uvc_video_chain *chain,
-			  struct uvc_control *ctrl,
-			  struct uvc_control_mapping *mapping,
-			  s32 *value)
+static int __uvc_ctrl_get_std(struct uvc_video_chain *chain,
+			      struct uvc_control *ctrl,
+			      struct uvc_control_mapping *mapping,
+			      s32 *value)
 {
 	int ret;
 
-	if ((ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR) == 0)
-		return -EACCES;
+	if (uvc_ctrl_mapping_is_compound(mapping))
+		return -EINVAL;
 
 	ret = __uvc_ctrl_load_cur(chain, ctrl);
 	if (ret < 0)
@@ -1199,7 +1199,7 @@ int uvc_ctrl_is_accessible(struct uvc_video_chain *chain, u32 v4l2_id,
 	if (!master_ctrl || !(master_ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR))
 		return 0;
 
-	ret = __uvc_ctrl_get(chain, master_ctrl, master_map, &val);
+	ret = __uvc_ctrl_get_std(chain, master_ctrl, master_map, &val);
 	if (ret >= 0 && val != mapping->master_manual)
 		return -EACCES;
 
@@ -1264,8 +1264,13 @@ static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain,
 		__uvc_find_control(ctrl->entity, mapping->master_id,
 				   &master_map, &master_ctrl, 0);
 	if (master_ctrl && (master_ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR)) {
-		s32 val;
-		int ret = __uvc_ctrl_get(chain, master_ctrl, master_map, &val);
+		s32 val = 0;
+		int ret;
+
+		if (uvc_ctrl_mapping_is_compound(master_map))
+			return -EINVAL;
+
+		ret = __uvc_ctrl_get_std(chain, master_ctrl, master_map, &val);
 		if (ret < 0)
 			return ret;
 
@@ -1532,7 +1537,8 @@ static void uvc_ctrl_send_slave_event(struct uvc_video_chain *chain,
 	if (ctrl == NULL)
 		return;
 
-	if (__uvc_ctrl_get(chain, ctrl, mapping, &val) == 0)
+	if (uvc_ctrl_mapping_is_compound(mapping) ||
+	    __uvc_ctrl_get_std(chain, ctrl, mapping, &val) == 0)
 		changes |= V4L2_EVENT_CTRL_CH_VALUE;
 
 	uvc_ctrl_send_event(chain, handle, ctrl, mapping, val, changes);
@@ -1703,7 +1709,8 @@ static int uvc_ctrl_add_event(struct v4l2_subscribed_event *sev, unsigned elems)
 		u32 changes = V4L2_EVENT_CTRL_CH_FLAGS;
 		s32 val = 0;
 
-		if (__uvc_ctrl_get(handle->chain, ctrl, mapping, &val) == 0)
+		if (uvc_ctrl_mapping_is_compound(mapping) ||
+		    __uvc_ctrl_get_std(handle->chain, ctrl, mapping, &val) == 0)
 			changes |= V4L2_EVENT_CTRL_CH_VALUE;
 
 		uvc_ctrl_fill_event(handle->chain, &ev, ctrl, mapping, val,
@@ -1883,7 +1890,10 @@ int uvc_ctrl_get(struct uvc_video_chain *chain,
 	if (ctrl == NULL)
 		return -EINVAL;
 
-	return __uvc_ctrl_get(chain, ctrl, mapping, &xctrl->value);
+	if (uvc_ctrl_mapping_is_compound(mapping))
+		return -EINVAL;
+	else
+		return __uvc_ctrl_get_std(chain, ctrl, mapping, &xctrl->value);
 }
 
 static int __uvc_ctrl_get_boundary_std(struct uvc_video_chain *chain,
@@ -2042,8 +2052,12 @@ int uvc_ctrl_set(struct uvc_fh *handle,
 		       ctrl->info.size);
 	}
 
-	mapping->set(mapping, value,
-		uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT));
+	if (uvc_ctrl_mapping_is_compound(mapping))
+		return -EINVAL;
+	else
+		mapping->set(mapping, value,
+			     uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT));
+
 
 	if (ctrl->info.flags & UVC_CTRL_FLAG_ASYNCHRONOUS)
 		ctrl->handle = handle;
-- 
2.43.0.rc2.451.g8631bc7472-goog