Hi Linh
Could you share the "lsusb -v " info of your device, and also what
are the raw values from the device for UVC_GET_MAX, UVC_GET_MIN for
UVC_CT_PANTILT_RELATIVE_CONTROL and UVC_CT_ZOOM_RELATIVE_CONTROL ?
Something like this (not tested :) ):
diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index e59a463c27618..76c7adc3aa579 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -415,7 +415,11 @@ static s32 uvc_ctrl_get_zoom(struct
uvc_control_mapping *mapping,
return (zoom == 0) ? 0 : (zoom > 0 ? data[2] : -data[2]);
case UVC_GET_MIN:
+ printk(KERN_ERR "zoom: GET_MIN 0%x 0x%x 0%x\n",
data[0], data[1], data[2]);
+ return data[2];
case UVC_GET_MAX:
+ printk(KERN_ERR "zoom: GET_MAX 0%x 0x%x 0%x\n",
data[0], data[1], data[2]);
+ fallthrough;
case UVC_GET_RES:
case UVC_GET_DEF:
default:
@@ -441,8 +445,11 @@ static s32 uvc_ctrl_get_rel_speed(struct
uvc_control_mapping *mapping,
return (rel == 0) ? 0 : (rel > 0 ? data[first+1]
: -data[first+1]);
case UVC_GET_MIN:
+ printk(KERN_ERR "speed: GET_MIN 0%x 0x%x 0%x\n",
data[first], data[first+1], data[first+2]);
return -data[first+1];
case UVC_GET_MAX:
+ printk(KERN_ERR "speed: GET_MAX 0%x 0x%x 0%x\n",
data[first], data[first+1], data[first+2]);
+ fallthrough;
case UVC_GET_RES:
case UVC_GET_DEF:
default:
Thanks!
On Tue, 19 Mar 2024 at 06:30, Linh Vu <linh.tp.vu@xxxxxxxxx> wrote:
>
> When mapping from UVC_CT_PANTILT_RELATIVE_CONTROL
> to V4L2_CID_PAN_SPEED and V4L2_CID_TILT_SPEED,
> and from UVC_CT_ZOOM_RELATIVE_CONTROL to V4L2_CID_ZOOM_CONTINUOUS,
> the minimum value of the movement should be negated of the maximum value.
>
> For example, if a UVC device (e.g., OBSBOT Tiny 2) declares a pan speed
> range [1, 160], its V4L2_CID_PAN_SPEED mapping has range [-160, 160].
>
> Currently, calling ioctl with VIDIOC_QUERY_EXT_CTRL and V4L2_CID_PAN_SPEED
> returns a minimum value of -1. When calling ioctl with VIDIOC_S_CTRL,
> V4L2_CID_PAN_SPEED and -100, the speed (velocity) of the pan movement gets
> clamped to -1.
>
> To get the minimum value of V4L2_CID_PAN_SPEED,
> uvc_ctrl_get_rel_speed is called with
> uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MIN) as data,
> which should be uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MAX).
>
> The same thing should be done for V4L2_CID_TILT_SPEED and
> V4L2_CID_ZOOM_CONTINUOUS.
>
> For V4L2_CID_ZOOM_CONTINUOUS, uvc_ctrl_get_zoom does not add the
> sign to the returned minimum value, so it's impossible to zoom out.
>
> Modify the data that is passed when querying the minimum
> value for V4L2_CID_PAN_SPEED, V4L2_CID_TILT_SPEED and
> V4L2_CID_ZOOM_CONTINUOUS.
> Also add sign to the returned minimum value in uvc_ctrl_get_zoom.
> Thus, the correct minimum value for relative PTZ controls can be returned.
>
> Signed-off-by: Linh Vu <linh.tp.vu@xxxxxxxxx>
> ---
> drivers/media/usb/uvc/uvc_ctrl.c | 24 +++++++++++++++++++-----
> 1 file changed, 19 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
> index e59a463c27618..00fd7e74e6d6b 100644
> --- a/drivers/media/usb/uvc/uvc_ctrl.c
> +++ b/drivers/media/usb/uvc/uvc_ctrl.c
> @@ -415,6 +415,7 @@ static s32 uvc_ctrl_get_zoom(struct uvc_control_mapping *mapping,
> return (zoom == 0) ? 0 : (zoom > 0 ? data[2] : -data[2]);
>
> case UVC_GET_MIN:
> + return -data[2];
> case UVC_GET_MAX:
> case UVC_GET_RES:
> case UVC_GET_DEF:
> @@ -1322,9 +1323,16 @@ static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain,
> break;
> }
>
> - if (ctrl->info.flags & UVC_CTRL_FLAG_GET_MIN)
> - v4l2_ctrl->minimum = mapping->get(mapping, UVC_GET_MIN,
> - uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MIN));
> + if (ctrl->info.flags & UVC_CTRL_FLAG_GET_MIN) {
> + if (v4l2_ctrl->id == V4L2_CID_PAN_SPEED
> + || v4l2_ctrl->id == V4L2_CID_TILT_SPEED
> + || v4l2_ctrl->id == V4L2_CID_ZOOM_CONTINUOUS)
> + v4l2_ctrl->minimum = mapping->get(mapping, UVC_GET_MIN,
> + uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MAX));
> + else
> + v4l2_ctrl->minimum = mapping->get(mapping, UVC_GET_MIN,
> + uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MIN));
> + }
>
> if (ctrl->info.flags & UVC_CTRL_FLAG_GET_MAX)
> v4l2_ctrl->maximum = mapping->get(mapping, UVC_GET_MAX,
> @@ -1909,9 +1917,15 @@ int uvc_ctrl_set(struct uvc_fh *handle,
> if (ret < 0)
> return ret;
> }
> + if (mapping->id == V4L2_CID_PAN_SPEED
> + || mapping->id == V4L2_CID_TILT_SPEED
> + || mapping->id == V4L2_CID_ZOOM_CONTINUOUS)
> + min = mapping->get(mapping, UVC_GET_MIN,
> + uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MAX));
> + else
> + min = mapping->get(mapping, UVC_GET_MIN,
> + uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MIN));
>
> - min = mapping->get(mapping, UVC_GET_MIN,
> - uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MIN));
> max = mapping->get(mapping, UVC_GET_MAX,
> uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MAX));
> step = mapping->get(mapping, UVC_GET_RES,
>
> base-commit: e0b8eb0f6d652981bfd9ba7c619c9d81ed087ad0
> --
> 2.34.1
>
>
--
Ricardo Ribalda
