media: uvcvideo: Refactor power_line_frequency_controls_limited

Move the control mapping to uvc_ctrl.c. This way we do not have
references to UVC controls or V4L2 controls in uvc_driver.c.

This also fixes a bug introduced in commit 38207560 ("media:
uvcvideo: Limit power line control for Quanta UVC Webcam"). The
offending commit caused the power line control menu entries to have
incorrect indices compared to the V4L2_CID_POWER_LINE_FREQUENCY_*
enumeration. Now that the limited mapping reuses the correct menu_info
array, the indices correctly map to the V4L2 control specification.

Fixes: 38207560 ("media: uvcvideo: Limit power line control for Quanta UVC Webcam")
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

drivers/media/usb/uvc/uvc_ctrl.c

@@ -723,6 +723,19 @@ static const struct uvc_control_mapping uvc_ctrl_mappings[] = {
 	},
 };
 
+const struct uvc_control_mapping uvc_ctrl_power_line_mapping_limited = {
+	.id		= V4L2_CID_POWER_LINE_FREQUENCY,
+	.entity		= UVC_GUID_UVC_PROCESSING,
+	.selector	= UVC_PU_POWER_LINE_FREQUENCY_CONTROL,
+	.size		= 2,
+	.offset		= 0,
+	.v4l2_type	= V4L2_CTRL_TYPE_MENU,
+	.data_type	= UVC_CTRL_DATA_TYPE_ENUM,
+	.menu_info	= power_line_frequency_controls,
+	.menu_mask	= GENMASK(V4L2_CID_POWER_LINE_FREQUENCY_60HZ,
+				  V4L2_CID_POWER_LINE_FREQUENCY_50HZ),
+};
+
 static const struct uvc_control_mapping uvc_ctrl_power_line_mapping_uvc11 = {
 	.id		= V4L2_CID_POWER_LINE_FREQUENCY,
 	.entity		= UVC_GUID_UVC_PROCESSING,

drivers/media/usb/uvc/uvc_driver.c

@@ -2358,24 +2358,6 @@ MODULE_PARM_DESC(timeout, "Streaming control requests timeout");
  * Driver initialization and cleanup
  */
 
-static const struct uvc_menu_info power_line_frequency_controls_limited[] = {
-	{ 1, "50 Hz" },
-	{ 2, "60 Hz" },
-};
-
-static const struct uvc_control_mapping uvc_ctrl_power_line_mapping_limited = {
-	.id		= V4L2_CID_POWER_LINE_FREQUENCY,
-	.entity		= UVC_GUID_UVC_PROCESSING,
-	.selector	= UVC_PU_POWER_LINE_FREQUENCY_CONTROL,
-	.size		= 2,
-	.offset		= 0,
-	.v4l2_type	= V4L2_CTRL_TYPE_MENU,
-	.data_type	= UVC_CTRL_DATA_TYPE_ENUM,
-	.menu_info	= power_line_frequency_controls_limited,
-	.menu_mask	=
-		GENMASK(ARRAY_SIZE(power_line_frequency_controls_limited) - 1, 0),
-};
-
 static const struct uvc_device_info uvc_ctrl_power_line_limited = {
 	.mappings = (const struct uvc_control_mapping *[]) {
 		&uvc_ctrl_power_line_mapping_limited,

drivers/media/usb/uvc/uvcvideo.h

@@ -745,6 +745,7 @@ int uvc_status_start(struct uvc_device *dev, gfp_t flags);
 void uvc_status_stop(struct uvc_device *dev);
 
 /* Controls */
+extern const struct uvc_control_mapping uvc_ctrl_power_line_mapping_limited;
 extern const struct v4l2_subscribed_event_ops uvc_ctrl_sub_ev_ops;
 
 int uvc_query_v4l2_ctrl(struct uvc_video_chain *chain,