media: uvcvideo: Add support for V4L2_CTRL_TYPE_CTRL_CLASS

Create all the class controls for the device defined controls.

Fixes v4l2-compliance:
Control ioctls (Input 0):
		fail: v4l2-test-controls.cpp(216): missing control class for class 00980000
		fail: v4l2-test-controls.cpp(216): missing control tclass for class 009a0000
	test VIDIOC_QUERY_EXT_CTRL/QUERYMENU: FAIL

Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/usb/uvc/uvc_ctrl.c

@@ -357,6 +357,11 @@ static const struct uvc_control_info uvc_ctrls[] = {
 	},
 };
 
+static const u32 uvc_control_classes[] = {
+	V4L2_CID_CAMERA_CLASS,
+	V4L2_CID_USER_CLASS,
+};
+
 static const struct uvc_menu_info power_line_frequency_controls[] = {
 	{ 0, "Disabled" },
 	{ 1, "50 Hz" },
@@ -1024,6 +1029,49 @@ static int __uvc_ctrl_get(struct uvc_video_chain *chain,
 	return 0;
 }
 
+static int __uvc_query_v4l2_class(struct uvc_video_chain *chain, u32 req_id,
+				  u32 found_id)
+{
+	bool find_next = req_id & V4L2_CTRL_FLAG_NEXT_CTRL;
+	unsigned int i;
+
+	req_id &= V4L2_CTRL_ID_MASK;
+
+	for (i = 0; i < ARRAY_SIZE(uvc_control_classes); i++) {
+		if (!(chain->ctrl_class_bitmap & BIT(i)))
+			continue;
+		if (!find_next) {
+			if (uvc_control_classes[i] == req_id)
+				return i;
+			continue;
+		}
+		if (uvc_control_classes[i] > req_id &&
+		    uvc_control_classes[i] < found_id)
+			return i;
+	}
+
+	return -ENODEV;
+}
+
+static int uvc_query_v4l2_class(struct uvc_video_chain *chain, u32 req_id,
+				u32 found_id, struct v4l2_queryctrl *v4l2_ctrl)
+{
+	int idx;
+
+	idx = __uvc_query_v4l2_class(chain, req_id, found_id);
+	if (idx < 0)
+		return -ENODEV;
+
+	memset(v4l2_ctrl, 0, sizeof(*v4l2_ctrl));
+	v4l2_ctrl->id = uvc_control_classes[idx];
+	strscpy(v4l2_ctrl->name, v4l2_ctrl_get_name(v4l2_ctrl->id),
+		sizeof(v4l2_ctrl->name));
+	v4l2_ctrl->type = V4L2_CTRL_TYPE_CTRL_CLASS;
+	v4l2_ctrl->flags = V4L2_CTRL_FLAG_WRITE_ONLY
+			 | V4L2_CTRL_FLAG_READ_ONLY;
+	return 0;
+}
+
 static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain,
 	struct uvc_control *ctrl,
 	struct uvc_control_mapping *mapping,
@@ -1127,12 +1175,31 @@ int uvc_query_v4l2_ctrl(struct uvc_video_chain *chain,
 	if (ret < 0)
 		return -ERESTARTSYS;
 
+	/* Check if the ctrl is a know class */
+	if (!(v4l2_ctrl->id & V4L2_CTRL_FLAG_NEXT_CTRL)) {
+		ret = uvc_query_v4l2_class(chain, v4l2_ctrl->id, 0, v4l2_ctrl);
+		if (!ret)
+			goto done;
+	}
+
 	ctrl = uvc_find_control(chain, v4l2_ctrl->id, &mapping);
 	if (ctrl == NULL) {
 		ret = -EINVAL;
 		goto done;
 	}
 
+	/*
+	 * If we're enumerating control with V4L2_CTRL_FLAG_NEXT_CTRL, check if
+	 * a class should be inserted between the previous control and the one
+	 * we have just found.
+	 */
+	if (v4l2_ctrl->id & V4L2_CTRL_FLAG_NEXT_CTRL) {
+		ret = uvc_query_v4l2_class(chain, v4l2_ctrl->id, mapping->id,
+					   v4l2_ctrl);
+		if (!ret)
+			goto done;
+	}
+
 	ret = __uvc_query_v4l2_ctrl(chain, ctrl, mapping, v4l2_ctrl);
 done:
 	mutex_unlock(&chain->ctrl_mutex);
@@ -1426,6 +1493,11 @@ static int uvc_ctrl_add_event(struct v4l2_subscribed_event *sev, unsigned elems)
 	if (ret < 0)
 		return -ERESTARTSYS;
 
+	if (__uvc_query_v4l2_class(handle->chain, sev->id, 0) >= 0) {
+		ret = 0;
+		goto done;
+	}
+
 	ctrl = uvc_find_control(handle->chain, sev->id, &mapping);
 	if (ctrl == NULL) {
 		ret = -EINVAL;
@@ -1459,7 +1531,10 @@ static void uvc_ctrl_del_event(struct v4l2_subscribed_event *sev)
 	struct uvc_fh *handle = container_of(sev->fh, struct uvc_fh, vfh);
 
 	mutex_lock(&handle->chain->ctrl_mutex);
+	if (__uvc_query_v4l2_class(handle->chain, sev->id, 0) >= 0)
+		goto done;
 	list_del(&sev->node);
+done:
 	mutex_unlock(&handle->chain->ctrl_mutex);
 }
 
@@ -1577,6 +1652,9 @@ int uvc_ctrl_get(struct uvc_video_chain *chain,
 	struct uvc_control *ctrl;
 	struct uvc_control_mapping *mapping;
 
+	if (__uvc_query_v4l2_class(chain, xctrl->id, 0) >= 0)
+		return -EACCES;
+
 	ctrl = uvc_find_control(chain, xctrl->id, &mapping);
 	if (ctrl == NULL)
 		return -EINVAL;
@@ -1596,6 +1674,9 @@ int uvc_ctrl_set(struct uvc_fh *handle,
 	s32 max;
 	int ret;
 
+	if (__uvc_query_v4l2_class(chain, xctrl->id, 0) >= 0)
+		return -EACCES;
+
 	ctrl = uvc_find_control(chain, xctrl->id, &mapping);
 	if (ctrl == NULL)
 		return -EINVAL;
@@ -2062,6 +2143,7 @@ static int __uvc_ctrl_add_mapping(struct uvc_video_chain *chain,
 {
 	struct uvc_control_mapping *map;
 	unsigned int size;
+	unsigned int i;
 
 	/* Most mappings come from static kernel data and need to be duplicated.
 	 * Mappings that come from userspace will be unnecessarily duplicated,
@@ -2085,6 +2167,14 @@ static int __uvc_ctrl_add_mapping(struct uvc_video_chain *chain,
 	if (map->set == NULL)
 		map->set = uvc_set_le_value;
 
+	for (i = 0; i < ARRAY_SIZE(uvc_control_classes); i++) {
+		if (V4L2_CTRL_ID2WHICH(uvc_control_classes[i]) ==
+						V4L2_CTRL_ID2WHICH(map->id)) {
+			chain->ctrl_class_bitmap |= BIT(i);
+			break;
+		}
+	}
+
 	list_add_tail(&map->list, &ctrl->info.mappings);
 	uvc_dbg(chain->dev, CONTROL, "Adding mapping '%s' to control %pUl/%u\n",
 		map->name, ctrl->info.entity, ctrl->info.selector);

drivers/media/usb/uvc/uvcvideo.h

@@ -476,6 +476,7 @@ struct uvc_video_chain {
 
 	struct v4l2_prio_state prio;		/* V4L2 priority state */
 	u32 caps;				/* V4L2 chain-wide caps */
+	u8 ctrl_class_bitmap;			/* Bitmap of valid classes */
 };
 
 struct uvc_stats_frame {