Hi Kieran,
Thank you for the patch.
On Thursday, 24 May 2018 19:16:12 EEST Kieran Bingham wrote:
> From: Kieran Bingham <kieran.bing...@ideasonboard.com>
>
> 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.
>
> Signed-off-by: Kieran Bingham <kieran.bing...@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinch...@ideasonboard.com>
> ---
> v2:
> - Fix commit title (f_uvc -> uvc)
> - Change identifier file name (now function_name)
> - Document in ABI
>
> .../ABI/testing/configfs-usb-gadget-uvc | 5 ++++
> drivers/usb/gadget/function/f_uvc.c | 24 ++++++++++++++++++-
> 2 files changed, 28 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/ABI/testing/configfs-usb-gadget-uvc
> b/Documentation/ABI/testing/configfs-usb-gadget-uvc index
> 1ba0d0fda9c0..9281e2aa38df 100644
> --- a/Documentation/ABI/testing/configfs-usb-gadget-uvc
> +++ b/Documentation/ABI/testing/configfs-usb-gadget-uvc
> @@ -263,3 +263,8 @@ Description: Specific streaming header descriptors
> is connected
> bmInfo - capabilities of this video streaming
> interface
> +
> +What:
> /sys/class/udc/udc.name/device/gadget/video4linux/video.name/
functio
> n_name +Date: May 2018
> +KernelVersion: 4.19
> +Description: UVC configfs function instance name
> diff --git a/drivers/usb/gadget/function/f_uvc.c
> b/drivers/usb/gadget/function/f_uvc.c index d82cd61676d3..c8627cc698f8
> 100644
> --- a/drivers/usb/gadget/function/f_uvc.c
> +++ b/drivers/usb/gadget/function/f_uvc.c
> @@ -421,10 +421,21 @@ 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;
> @@ -437,7 +448,17 @@ 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) \
> @@ -877,6 +898,7 @@ 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);
--
Regards,
Laurent Pinchart
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