Hi Laurent

On Sun, 29 Jun 2025 at 20:13, Laurent Pinchart
[off-list ref] wrote:

Hi Ricardo,

Thank you for the patch.

On Thu, Jun 05, 2025 at 05:53:03PM +0000, Ricardo Ribalda wrote:

quoted

Virtual entities need to provide more values than get_cur and get_cur

I think you meant "get_info and get_cur".

quoted

for their controls. Add support for get_def, get_min, get_max and
get_res.

Do they ? The UVC specification defines controls that don't list
GET_DEF, GET_MIN, GET_MAX and GET_RES as mandatory requests. Can't we do
the same for the software controls ? This patch is meant to support the
UVC_SWENTITY_ORIENTATION and UVC_SWENTITY_ROTATION control in the next
patch, and those are read-only controls. Aren't GET_INFO and GET_CUR
enough ?

V4L2_CID_CAMERA_ROTATION has the type UVC_CTRL_DATA_TYPE_UNSIGNED,
that time requires get_min and get_max.
We can create a new type UVC_CTRL_DATA_TYPE_UNSIGNED_READ_ONLY that
fakes min, max and res, but I think that it is cleaner this approach.

quoted

This is a preparation patch.

Signed-off-by: Ricardo Ribalda <redacted>
---
 drivers/media/usb/uvc/uvc_ctrl.c | 12 ++++++++++++
 drivers/media/usb/uvc/uvcvideo.h |  8 ++++++++
 2 files changed, 20 insertions(+)

diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index 21ec7b978bc7aca21db7cb8fd5d135d876f3330c..59be62ae24a4219fa9d7aacf2ae7382c95362178 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c

@@ -596,6 +596,18 @@ static int uvc_ctrl_query_entity(struct uvc_device *dev,
      if (query == UVC_GET_CUR && ctrl->entity->get_cur)
              return ctrl->entity->get_cur(dev, ctrl->entity,
                                           ctrl->info.selector, data, len);
+     if (query == UVC_GET_DEF && ctrl->entity->get_def)
+             return ctrl->entity->get_def(dev, ctrl->entity,
+                                          ctrl->info.selector, data, len);
+     if (query == UVC_GET_MIN && ctrl->entity->get_min)
+             return ctrl->entity->get_min(dev, ctrl->entity,
+                                          ctrl->info.selector, data, len);
+     if (query == UVC_GET_MAX && ctrl->entity->get_max)
+             return ctrl->entity->get_max(dev, ctrl->entity,
+                                          ctrl->info.selector, data, len);
+     if (query == UVC_GET_RES && ctrl->entity->get_res)
+             return ctrl->entity->get_res(dev, ctrl->entity,
+                                          ctrl->info.selector, data, len);
      if (query == UVC_GET_INFO && ctrl->entity->get_info)
              return ctrl->entity->get_info(dev, ctrl->entity,
                                            ctrl->info.selector, data);

diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index a931750bdea25b9062dcc7644bf5f2ed89c1cb4c..d6da8ed3ad4cf3377df49923e051fe04d83d2e38 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h

@@ -261,6 +261,14 @@ struct uvc_entity {
                      u8 cs, u8 *caps);
      int (*get_cur)(struct uvc_device *dev, struct uvc_entity *entity,
                     u8 cs, void *data, u16 size);
+     int (*get_def)(struct uvc_device *dev, struct uvc_entity *entity,
+                    u8 cs, void *data, u16 size);
+     int (*get_min)(struct uvc_device *dev, struct uvc_entity *entity,
+                    u8 cs, void *data, u16 size);
+     int (*get_max)(struct uvc_device *dev, struct uvc_entity *entity,
+                    u8 cs, void *data, u16 size);
+     int (*get_res)(struct uvc_device *dev, struct uvc_entity *entity,
+                    u8 cs, void *data, u16 size);

      unsigned int ncontrols;
      struct uvc_control *controls;

--
Regards,

Laurent Pinchart

-- 
Ricardo Ribalda