From: Edgar Thier <info@xxxxxxxxxxxxxx>
Use flags the device exposes for UVC controls.
This allows the device to define which property flags are set.
Since some cameras offer auto-adjustments for properties (e.g. auto-gain),
the values of other properties (e.g. gain) can change in the camera.
Examining the flags ensures that the driver is aware of such properties.
Signed-off-by: Edgar Thier <info@xxxxxxxxxxxxxx>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
---
drivers/media/usb/uvc/uvc_ctrl.c | 52 ++++++++++++++++++++++++++++++----------
1 file changed, 39 insertions(+), 13 deletions(-)
diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index 20397aba6849..586f0e94061b 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -1590,6 +1590,36 @@ int uvc_ctrl_set(struct uvc_video_chain *chain,
* Dynamic controls
*/
+/*
+ * Retrieve flags for a given control
+ */
+static int uvc_ctrl_get_flags(struct uvc_device *dev,
+ const struct uvc_control *ctrl,
+ struct uvc_control_info *info)
+{
+ u8 *data;
+ int ret;
+
+ data = kmalloc(1, GFP_KERNEL);
+ if (data == NULL)
+ return -ENOMEM;
+
+ ret = uvc_query_ctrl(dev, UVC_GET_INFO, ctrl->entity->id, dev->intfnum,
+ info->selector, data, 1);
+ if (!ret)
+ info->flags = UVC_CTRL_FLAG_GET_MIN | UVC_CTRL_FLAG_GET_MAX
+ | UVC_CTRL_FLAG_GET_RES | UVC_CTRL_FLAG_GET_DEF
+ | (data[0] & UVC_CONTROL_CAP_GET ?
+ UVC_CTRL_FLAG_GET_CUR : 0)
+ | (data[0] & UVC_CONTROL_CAP_SET ?
+ UVC_CTRL_FLAG_SET_CUR : 0)
+ | (data[0] & UVC_CONTROL_CAP_AUTOUPDATE ?
+ UVC_CTRL_FLAG_AUTO_UPDATE : 0);
+
+ kfree(data);
+ return ret;
+}
+
static void uvc_ctrl_fixup_xu_info(struct uvc_device *dev,
const struct uvc_control *ctrl, struct uvc_control_info *info)
{
@@ -1659,25 +1689,14 @@ static int uvc_ctrl_fill_xu_info(struct uvc_device *dev,
info->size = le16_to_cpup((__le16 *)data);
- /* Query the control information (GET_INFO) */
- ret = uvc_query_ctrl(dev, UVC_GET_INFO, ctrl->entity->id, dev->intfnum,
- info->selector, data, 1);
+ ret = uvc_ctrl_get_flags(dev, ctrl, info);
if (ret < 0) {
uvc_trace(UVC_TRACE_CONTROL,
- "GET_INFO failed on control %pUl/%u (%d).\n",
+ "Failed to get flags for control %pUl/%u (%d).\n",
info->entity, info->selector, ret);
goto done;
}
- info->flags = UVC_CTRL_FLAG_GET_MIN | UVC_CTRL_FLAG_GET_MAX
- | UVC_CTRL_FLAG_GET_RES | UVC_CTRL_FLAG_GET_DEF
- | (data[0] & UVC_CONTROL_CAP_GET ?
- UVC_CTRL_FLAG_GET_CUR : 0)
- | (data[0] & UVC_CONTROL_CAP_SET ?
- UVC_CTRL_FLAG_SET_CUR : 0)
- | (data[0] & UVC_CONTROL_CAP_AUTOUPDATE ?
- UVC_CTRL_FLAG_AUTO_UPDATE : 0);
-
uvc_ctrl_fixup_xu_info(dev, ctrl, info);
uvc_trace(UVC_TRACE_CONTROL, "XU control %pUl/%u queried: len %u, "
@@ -1902,6 +1921,13 @@ static int uvc_ctrl_add_info(struct uvc_device *dev, struct uvc_control *ctrl,
goto done;
}
+ /*
+ * Retrieve control flags from the device. Ignore errors and work with
+ * default flag values from the uvc_ctrl array when the device doesn't
+ * properly implement GET_INFO on standard controls.
+ */
+ uvc_ctrl_get_flags(dev, ctrl, &ctrl->info);
+
ctrl->initialized = 1;
uvc_trace(UVC_TRACE_CONTROL, "Added control %pUl/%u to device %s "
--
Regards,
Laurent Pinchart
