[media] uvcvideo: Hardcode the index/selector relationship for XU controls

Devices advertise XU controls using a bitmask, in which each bit
corresponds to a control. The control selector, used to query the
control, isn't available in the USB descriptors.

All known UVC devices use control selectors equal to the control bit
index plus one. Hardcode that relationship in the driver, making the
UVCIOC_CTRL_ADD ioctl obsolete. All necessary information about XU
controls can be obtained by the driver at enumeration time.

The UVCIOC_CTRL_ADD ioctl is still supported for compatibility reasons,
but now always returns -EEXIST.

Finally, control mappings are now on a per-device basis and no longer
global.

As this changes the userspace interface, bump the driver version number
to 1.0.0 (it was about time).

Signed-off-by: Martin Rubli <martin_rubli@logitech.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 13 insertions, 33 deletions

diff --git a/drivers/media/video/uvc/uvc_v4l2.c b/drivers/media/video/uvc/uvc_v4l2.c
index 8cecd1cc0ed..4a510483f7c 100644
--- a/drivers/media/video/uvc/uvc_v4l2.c
+++ b/drivers/media/video/uvc/uvc_v4l2.c
@@ -31,7 +31,8 @@
 /* ------------------------------------------------------------------------
  * UVC ioctls
  */
-static int uvc_ioctl_ctrl_map(struct uvc_xu_control_mapping *xmap, int old)
+static int uvc_ioctl_ctrl_map(struct uvc_video_chain *chain,
+	struct uvc_xu_control_mapping *xmap, int old)
 {
 	struct uvc_control_mapping *map;
 	unsigned int size;
@@ -58,6 +59,8 @@ static int uvc_ioctl_ctrl_map(struct uvc_xu_control_mapping *xmap, int old)
 
 	case V4L2_CTRL_TYPE_MENU:
 		if (old) {
+			uvc_trace(UVC_TRACE_CONTROL, "V4L2_CTRL_TYPE_MENU not "
+				  "supported for UVCIOC_CTRL_MAP_OLD.\n");
 			ret = -EINVAL;
 			goto done;
 		}
@@ -78,17 +81,17 @@ static int uvc_ioctl_ctrl_map(struct uvc_xu_control_mapping *xmap, int old)
 		break;
 
 	default:
+		uvc_trace(UVC_TRACE_CONTROL, "Unsupported V4L2 control type "
+			  "%u.\n", xmap->v4l2_type);
 		ret = -EINVAL;
 		goto done;
 	}
 
-	ret = uvc_ctrl_add_mapping(map);
+	ret = uvc_ctrl_add_mapping(chain, map);
 
 done:
-	if (ret < 0) {
-		kfree(map->menu_info);
-		kfree(map);
-	}
+	kfree(map->menu_info);
+	kfree(map);
 
 	return ret;
 }
@@ -1021,42 +1024,19 @@ static long uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
 
 	/* Dynamic controls. */
 	case UVCIOC_CTRL_ADD:
-	{
-		struct uvc_xu_control_info *xinfo = arg;
-		struct uvc_control_info *info;
-
+		/* Legacy ioctl, kept for API compatibility reasons */
 		if (!capable(CAP_SYS_ADMIN))
 			return -EPERM;
 
-		if (xinfo->size == 0)
-			return -EINVAL;
-
-		info = kzalloc(sizeof *info, GFP_KERNEL);
-		if (info == NULL)
-			return -ENOMEM;
-
-		memcpy(info->entity, xinfo->entity, sizeof info->entity);
-		info->index = xinfo->index;
-		info->selector = xinfo->selector;
-		info->size = xinfo->size;
-		info->flags = xinfo->flags;
-
-		info->flags |= UVC_CONTROL_GET_MIN | UVC_CONTROL_GET_MAX |
-			       UVC_CONTROL_GET_RES | UVC_CONTROL_GET_DEF |
-			       UVC_CONTROL_EXTENSION;
-
-		ret = uvc_ctrl_add_info(info);
-		if (ret < 0)
-			kfree(info);
-		break;
-	}
+		return -EEXIST;
 
 	case UVCIOC_CTRL_MAP_OLD:
 	case UVCIOC_CTRL_MAP:
 		if (!capable(CAP_SYS_ADMIN))
 			return -EPERM;
 
-		return uvc_ioctl_ctrl_map(arg, cmd == UVCIOC_CTRL_MAP_OLD);
+		return uvc_ioctl_ctrl_map(chain, arg,
+					  cmd == UVCIOC_CTRL_MAP_OLD);
 
 	case UVCIOC_CTRL_GET:
 		return uvc_xu_ctrl_query(chain, arg, 0);