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authorKieran Bingham <kieran.bingham@ideasonboard.com>2018-05-24 17:16:12 +0100
committerFelipe Balbi <felipe.balbi@linux.intel.com>2018-07-26 13:43:18 +0300
commitd7af78b9245545908c90bce2206f200a4250b5db (patch)
treef3092d857fcf83faff5ba3a21ce2e1786a6710da /drivers/usb/gadget
parentc728effd56d35c12774210f0732b8eb8b7ce7cd9 (diff)
usb: gadget: uvc: Expose configuration name through video node
When utilising multiple instantiations of a UVC gadget on a composite device, there is no clear method to link a particular configuration to its respective video node. Provide a means for identifying the correct video node by exposing the name of the function configuration through sysfs. Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Diffstat (limited to 'drivers/usb/gadget')
-rw-r--r--drivers/usb/gadget/function/f_uvc.c24
1 files changed, 23 insertions, 1 deletions
diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c
index 1d2feac5c532..d8ce7868fe22 100644
--- a/drivers/usb/gadget/function/f_uvc.c
+++ b/drivers/usb/gadget/function/f_uvc.c
@@ -413,10 +413,21 @@ uvc_function_disconnect(struct uvc_device *uvc)
* USB probe and disconnect
*/
+static ssize_t function_name_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct uvc_device *uvc = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%s\n", uvc->func.fi->group.cg_item.ci_name);
+}
+
+static DEVICE_ATTR_RO(function_name);
+
static int
uvc_register_video(struct uvc_device *uvc)
{
struct usb_composite_dev *cdev = uvc->func.config->cdev;
+ int ret;
/* TODO reference counting. */
uvc->vdev.v4l2_dev = &uvc->v4l2_dev;
@@ -429,7 +440,17 @@ uvc_register_video(struct uvc_device *uvc)
video_set_drvdata(&uvc->vdev, uvc);
- return video_register_device(&uvc->vdev, VFL_TYPE_GRABBER, -1);
+ ret = video_register_device(&uvc->vdev, VFL_TYPE_GRABBER, -1);
+ if (ret < 0)
+ return ret;
+
+ ret = device_create_file(&uvc->vdev.dev, &dev_attr_function_name);
+ if (ret < 0) {
+ video_unregister_device(&uvc->vdev);
+ return ret;
+ }
+
+ return 0;
}
#define UVC_COPY_DESCRIPTOR(mem, dst, desc) \
@@ -867,6 +888,7 @@ static void uvc_unbind(struct usb_configuration *c, struct usb_function *f)
INFO(cdev, "%s\n", __func__);
+ device_remove_file(&uvc->vdev.dev, &dev_attr_function_name);
video_unregister_device(&uvc->vdev);
v4l2_device_unregister(&uvc->v4l2_dev);