[PATCH v2 09/12] media: uvcvideo: Add uvc_ctrl_query_entity helper

[Ricardo Ribalda <ribalda@chromium.org>]

Create a helper function to query a control. The new function reduces
the number of arguments, calculates the length of the operation and
redirects the operation to the hardware or to the entity private
functions.

Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
 drivers/media/usb/uvc/uvc_ctrl.c | 81 ++++++++++++++++++++--------------------
 1 file changed, 41 insertions(+), 40 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index b2768080c08aafa85acb9b7f318672c043d84e55..21ec7b978bc7aca21db7cb8fd5d135d876f3330c 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -576,6 +576,34 @@ static const struct uvc_control_mapping uvc_ctrl_power_line_mapping_uvc15 = {
 				  V4L2_CID_POWER_LINE_FREQUENCY_DISABLED),
 };
 
+static int uvc_ctrl_query_entity(struct uvc_device *dev,
+				 const struct uvc_control *ctrl, u8 query,
+				 void *data)
+{
+	u16 len;
+
+	switch (query) {
+	case UVC_GET_INFO:
+		len = 1;
+		break;
+	case UVC_GET_LEN:
+		len = 2;
+		break;
+	default:
+		len = ctrl->info.size;
+	}
+
+	if (query == UVC_GET_CUR && ctrl->entity->get_cur)
+		return ctrl->entity->get_cur(dev, ctrl->entity,
+					     ctrl->info.selector, data, len);
+	if (query == UVC_GET_INFO && ctrl->entity->get_info)
+		return ctrl->entity->get_info(dev, ctrl->entity,
+					      ctrl->info.selector, data);
+
+	return uvc_query_ctrl(dev, query, ctrl->entity->id, dev->intfnum,
+			      ctrl->info.selector, data, len);
+}
+
 static const struct uvc_control_mapping *uvc_ctrl_filter_plf_mapping(
 	struct uvc_video_chain *chain, struct uvc_control *ctrl)
 {
@@ -1222,35 +1250,27 @@ static int uvc_ctrl_populate_cache(struct uvc_video_chain *chain,
 	int ret;
 
 	if (ctrl->info.flags & UVC_CTRL_FLAG_GET_DEF) {
-		ret = uvc_query_ctrl(chain->dev, UVC_GET_DEF, ctrl->entity->id,
-				     chain->dev->intfnum, ctrl->info.selector,
-				     uvc_ctrl_data(ctrl, UVC_CTRL_DATA_DEF),
-				     ctrl->info.size);
+		ret = uvc_ctrl_query_entity(chain->dev, ctrl, UVC_GET_DEF,
+					uvc_ctrl_data(ctrl, UVC_CTRL_DATA_DEF));
 		if (ret < 0)
 			return ret;
 	}
 
 	if (ctrl->info.flags & UVC_CTRL_FLAG_GET_MIN) {
-		ret = uvc_query_ctrl(chain->dev, UVC_GET_MIN, ctrl->entity->id,
-				     chain->dev->intfnum, ctrl->info.selector,
-				     uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MIN),
-				     ctrl->info.size);
+		ret = uvc_ctrl_query_entity(chain->dev, ctrl, UVC_GET_MIN,
+					uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MIN));
 		if (ret < 0)
 			return ret;
 	}
 	if (ctrl->info.flags & UVC_CTRL_FLAG_GET_MAX) {
-		ret = uvc_query_ctrl(chain->dev, UVC_GET_MAX, ctrl->entity->id,
-				     chain->dev->intfnum, ctrl->info.selector,
-				     uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MAX),
-				     ctrl->info.size);
+		ret = uvc_ctrl_query_entity(chain->dev, ctrl, UVC_GET_MAX,
+					uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MAX));
 		if (ret < 0)
 			return ret;
 	}
 	if (ctrl->info.flags & UVC_CTRL_FLAG_GET_RES) {
-		ret = uvc_query_ctrl(chain->dev, UVC_GET_RES, ctrl->entity->id,
-				     chain->dev->intfnum, ctrl->info.selector,
-				     uvc_ctrl_data(ctrl, UVC_CTRL_DATA_RES),
-				     ctrl->info.size);
+		ret = uvc_ctrl_query_entity(chain->dev, ctrl, UVC_GET_RES,
+					uvc_ctrl_data(ctrl, UVC_CTRL_DATA_RES));
 		if (ret < 0) {
 			if (UVC_ENTITY_TYPE(ctrl->entity) !=
 			    UVC_VC_EXTENSION_UNIT)
@@ -1291,16 +1311,7 @@ static int __uvc_ctrl_load_cur(struct uvc_video_chain *chain,
 		return 0;
 	}
 
-	if (ctrl->entity->get_cur)
-		ret = ctrl->entity->get_cur(chain->dev, ctrl->entity,
-					    ctrl->info.selector, data,
-					    ctrl->info.size);
-	else
-		ret = uvc_query_ctrl(chain->dev, UVC_GET_CUR,
-				     ctrl->entity->id, chain->dev->intfnum,
-				     ctrl->info.selector, data,
-				     ctrl->info.size);
-
+	ret = uvc_ctrl_query_entity(chain->dev, ctrl, UVC_GET_CUR, data);
 	if (ret < 0)
 		return ret;
 
@@ -2164,11 +2175,8 @@ static int uvc_ctrl_commit_entity(struct uvc_device *dev,
 			continue;
 
 		if (!rollback)
-			ret = uvc_query_ctrl(dev, UVC_SET_CUR, ctrl->entity->id,
-				dev->intfnum, ctrl->info.selector,
-				uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
-				ctrl->info.size);
-
+			ret = uvc_ctrl_query_entity(dev, ctrl, UVC_SET_CUR,
+				uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT));
 		if (!ret)
 			processed_ctrls++;
 
@@ -2570,13 +2578,7 @@ static int uvc_ctrl_get_flags(struct uvc_device *dev,
 	if (data == NULL)
 		return -ENOMEM;
 
-	if (ctrl->entity->get_info)
-		ret = ctrl->entity->get_info(dev, ctrl->entity,
-					     ctrl->info.selector, data);
-	else
-		ret = uvc_query_ctrl(dev, UVC_GET_INFO, ctrl->entity->id,
-				     dev->intfnum, info->selector, data, 1);
-
+	ret = uvc_ctrl_query_entity(dev, ctrl, UVC_GET_INFO, data);
 	if (!ret) {
 		info->flags &= ~(UVC_CTRL_FLAG_GET_CUR |
 				 UVC_CTRL_FLAG_SET_CUR |
@@ -2654,8 +2656,7 @@ static int uvc_ctrl_fill_xu_info(struct uvc_device *dev,
 	info->selector = ctrl->index + 1;
 
 	/* Query and verify the control length (GET_LEN) */
-	ret = uvc_query_ctrl(dev, UVC_GET_LEN, ctrl->entity->id, dev->intfnum,
-			     info->selector, data, 2);
+	ret = uvc_ctrl_query_entity(dev, ctrl, UVC_GET_LEN, data);
 	if (ret < 0) {
 		uvc_dbg(dev, CONTROL,
 			"GET_LEN failed on control %pUl/%u (%d)\n",

-- 
2.50.0.rc0.642.g800a2b2222-goog