media: uvcvideo: support V4L2_CTRL_WHICH_MIN/MAX_VAL

JIRA: https://issues.redhat.com/browse/RHEL-78934

commit 39d2c89
Author: Yunke Cao <yunkec@google.com>
Date: Mon, 3 Feb 2025 11:55:48 +0000

  Add support for V4L2_CTRL_WHICH_MIN/MAX_VAL in uvc driver.
  It is needed for the V4L2_CID_UVC_REGION_OF_INTEREST_RECT control.

  Signed-off-by: Yunke Cao <yunkec@google.com>
  Tested-by: Yunke Cao <yunkec@google.com>
  Reviewed-by: Hans de Goede <hdegoede@redhat.com>
  Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
  Link: https://lore.kernel.org/r/20250203-uvc-roi-v17-12-5900a9fed613@chromium.org
  Signed-off-by: Hans de Goede <hdegoede@redhat.com>
  Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>

Signed-off-by: Desnes Nunes <desnesn@redhat.com>

Author: Desnes Nunes

drivers/media/usb/uvc/uvc_ctrl.c

@@ -1277,6 +1277,37 @@ static int uvc_query_v4l2_class(struct uvc_video_chain *chain, u32 req_id,
 	return 0;
 }
 
+static bool uvc_ctrl_is_readable(u32 which, struct uvc_control *ctrl,
+				 struct uvc_control_mapping *mapping)
+{
+	if (which == V4L2_CTRL_WHICH_CUR_VAL)
+		return !!(ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR);
+
+	if (which == V4L2_CTRL_WHICH_DEF_VAL)
+		return !!(ctrl->info.flags & UVC_CTRL_FLAG_GET_DEF);
+
+	/* Types with implicit boundaries. */
+	switch (mapping->v4l2_type) {
+	case V4L2_CTRL_TYPE_MENU:
+	case V4L2_CTRL_TYPE_BOOLEAN:
+	case V4L2_CTRL_TYPE_BUTTON:
+		return true;
+	case V4L2_CTRL_TYPE_BITMASK:
+		return (ctrl->info.flags & UVC_CTRL_FLAG_GET_RES) ||
+			(ctrl->info.flags & UVC_CTRL_FLAG_GET_MAX);
+	default:
+		break;
+	}
+
+	if (which == V4L2_CTRL_WHICH_MIN_VAL)
+		return !!(ctrl->info.flags & UVC_CTRL_FLAG_GET_MIN);
+
+	if (which == V4L2_CTRL_WHICH_MAX_VAL)
+		return !!(ctrl->info.flags & UVC_CTRL_FLAG_GET_MAX);
+
+	return false;
+}
+
 /*
  * Check if control @v4l2_id can be accessed by the given control @ioctl
  * (VIDIOC_G_EXT_CTRLS, VIDIOC_TRY_EXT_CTRLS or VIDIOC_S_EXT_CTRLS).
@@ -1295,7 +1326,6 @@ int uvc_ctrl_is_accessible(struct uvc_video_chain *chain, u32 v4l2_id,
 	struct uvc_control *master_ctrl = NULL;
 	struct uvc_control_mapping *mapping;
 	struct uvc_control *ctrl;
-	bool read = ioctl == VIDIOC_G_EXT_CTRLS;
 	s32 val;
 	int ret;
 	int i;
@@ -1307,10 +1337,10 @@ int uvc_ctrl_is_accessible(struct uvc_video_chain *chain, u32 v4l2_id,
 	if (!ctrl)
 		return -EINVAL;
 
-	if (!(ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR) && read)
-		return -EACCES;
+	if (ioctl == VIDIOC_G_EXT_CTRLS)
+		return uvc_ctrl_is_readable(ctrls->which, ctrl, mapping);
 
-	if (!(ctrl->info.flags & UVC_CTRL_FLAG_SET_CUR) && !read)
+	if (!(ctrl->info.flags & UVC_CTRL_FLAG_SET_CUR))
 		return -EACCES;
 
 	if (ioctl != VIDIOC_S_EXT_CTRLS || !mapping->master_id)
@@ -1459,6 +1489,9 @@ static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain,
 		v4l2_ctrl->flags |= V4L2_CTRL_FLAG_WRITE_ONLY;
 	if (!(ctrl->info.flags & UVC_CTRL_FLAG_SET_CUR))
 		v4l2_ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
+	if ((ctrl->info.flags & UVC_CTRL_FLAG_GET_MAX) &&
+	    (ctrl->info.flags & UVC_CTRL_FLAG_GET_MIN))
+		v4l2_ctrl->flags |= V4L2_CTRL_FLAG_HAS_WHICH_MIN_MAX;
 
 	if (mapping->master_id)
 		__uvc_find_control(ctrl->entity, mapping->master_id,
@@ -2088,16 +2121,18 @@ static int uvc_mapping_get_xctrl_compound(struct uvc_video_chain *chain,
 
 	switch (which) {
 	case V4L2_CTRL_WHICH_CUR_VAL:
-		ret = __uvc_ctrl_load_cur(chain, ctrl);
-		if (ret < 0)
-			return ret;
 		id = UVC_CTRL_DATA_CURRENT;
 		query = UVC_GET_CUR;
 		break;
+	case V4L2_CTRL_WHICH_MIN_VAL:
+		id = UVC_CTRL_DATA_MIN;
+		query = UVC_GET_MIN;
+		break;
+	case V4L2_CTRL_WHICH_MAX_VAL:
+		id = UVC_CTRL_DATA_MAX;
+		query = UVC_GET_MAX;
+		break;
 	case V4L2_CTRL_WHICH_DEF_VAL:
-		ret = uvc_ctrl_populate_cache(chain, ctrl);
-		if (ret < 0)
-			return ret;
 		id = UVC_CTRL_DATA_DEF;
 		query = UVC_GET_DEF;
 		break;
@@ -2115,6 +2150,14 @@ static int uvc_mapping_get_xctrl_compound(struct uvc_video_chain *chain,
 	if (!data)
 		return -ENOMEM;
 
+	if (which == V4L2_CTRL_WHICH_CUR_VAL)
+		ret = __uvc_ctrl_load_cur(chain, ctrl);
+	else
+		ret = uvc_ctrl_populate_cache(chain, ctrl);
+
+	if (ret < 0)
+		return ret;
+
 	ret = mapping->get(mapping, query, uvc_ctrl_data(ctrl, id), size, data);
 	if (ret < 0)
 		return ret;
@@ -2132,22 +2175,37 @@ static int uvc_mapping_get_xctrl_std(struct uvc_video_chain *chain,
 				     struct uvc_control_mapping *mapping,
 				     u32 which, struct v4l2_ext_control *xctrl)
 {
+	struct v4l2_queryctrl qc;
+	int ret;
+
 	switch (which) {
 	case V4L2_CTRL_WHICH_CUR_VAL:
 		return __uvc_ctrl_get(chain, ctrl, mapping, &xctrl->value);
 	case V4L2_CTRL_WHICH_DEF_VAL:
-		if (!ctrl->cached) {
-			int ret = uvc_ctrl_populate_cache(chain, ctrl);
+	case V4L2_CTRL_WHICH_MIN_VAL:
+	case V4L2_CTRL_WHICH_MAX_VAL:
+		break;
+	default:
+		return -EINVAL;
+	}
 
-			if (ret < 0)
-				return ret;
-		}
-		xctrl->value = uvc_mapping_get_s32(mapping, UVC_GET_DEF,
-						   uvc_ctrl_data(ctrl, UVC_CTRL_DATA_DEF));
-		return 0;
+	ret = __uvc_queryctrl_boundaries(chain, ctrl, mapping, &qc);
+	if (ret < 0)
+		return ret;
+
+	switch (which) {
+	case V4L2_CTRL_WHICH_DEF_VAL:
+		xctrl->value = qc.default_value;
+		break;
+	case V4L2_CTRL_WHICH_MIN_VAL:
+		xctrl->value = qc.minimum;
+		break;
+	case V4L2_CTRL_WHICH_MAX_VAL:
+		xctrl->value = qc.maximum;
+		break;
 	}
 
-	return -EINVAL;
+	return 0;
 }
 
 static int uvc_mapping_get_xctrl(struct uvc_video_chain *chain,

drivers/media/usb/uvc/uvc_v4l2.c

@@ -1036,6 +1036,8 @@ static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,
 	switch (ctrls->which) {
 	case V4L2_CTRL_WHICH_DEF_VAL:
 	case V4L2_CTRL_WHICH_CUR_VAL:
+	case V4L2_CTRL_WHICH_MAX_VAL:
+	case V4L2_CTRL_WHICH_MIN_VAL:
 		which = ctrls->which;
 		break;
 	default: