V4L/DVB: uvcvideo: Support menu controls in the control mapping API

The UVCIOC_CTRL_MAP ioctl doesn't support menu entries for menu
controls. As the uvc_xu_control_mapping structure has no reserved
fields, this can't be fixed while keeping ABI compatibility.

Modify the UVCIOC_CTRL_MAP ioctl to add menu entries support, and define
UVCIOC_CTRL_MAP_OLD that supports the old ABI without any ability to add
menu controls.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/uvc/uvc_ctrl.c

@@ -1606,6 +1606,28 @@ void uvc_ctrl_cleanup_device(struct uvc_device *dev)
 	}
 }
 
+void uvc_ctrl_cleanup(void)
+{
+	struct uvc_control_info *info;
+	struct uvc_control_info *ni;
+	struct uvc_control_mapping *mapping;
+	struct uvc_control_mapping *nm;
+
+	list_for_each_entry_safe(info, ni, &uvc_driver.controls, list) {
+		if (!(info->flags & UVC_CONTROL_EXTENSION))
+			continue;
+
+		list_for_each_entry_safe(mapping, nm, &info->mappings, list) {
+			list_del(&mapping->list);
+			kfree(mapping->menu_info);
+			kfree(mapping);
+		}
+
+		list_del(&info->list);
+		kfree(info);
+	}
+}
+
 void uvc_ctrl_init(void)
 {
 	struct uvc_control_info *ctrl = uvc_ctrls;

drivers/media/video/uvc/uvc_driver.c

@@ -2260,6 +2260,7 @@ static int __init uvc_init(void)
 static void __exit uvc_cleanup(void)
 {
 	usb_deregister(&uvc_driver.driver);
+	uvc_ctrl_cleanup();
 }
 
 module_init(uvc_init);

drivers/media/video/uvc/uvc_v4l2.c

@@ -28,6 +28,71 @@
 
 #include "uvcvideo.h"
 
+/* ------------------------------------------------------------------------
+ * UVC ioctls
+ */
+static int uvc_ioctl_ctrl_map(struct uvc_xu_control_mapping *xmap, int old)
+{
+	struct uvc_control_mapping *map;
+	unsigned int size;
+	int ret;
+
+	map = kzalloc(sizeof *map, GFP_KERNEL);
+	if (map == NULL)
+		return -ENOMEM;
+
+	map->id = xmap->id;
+	memcpy(map->name, xmap->name, sizeof map->name);
+	memcpy(map->entity, xmap->entity, sizeof map->entity);
+	map->selector = xmap->selector;
+	map->size = xmap->size;
+	map->offset = xmap->offset;
+	map->v4l2_type = xmap->v4l2_type;
+	map->data_type = xmap->data_type;
+
+	switch (xmap->v4l2_type) {
+	case V4L2_CTRL_TYPE_INTEGER:
+	case V4L2_CTRL_TYPE_BOOLEAN:
+	case V4L2_CTRL_TYPE_BUTTON:
+		break;
+
+	case V4L2_CTRL_TYPE_MENU:
+		if (old) {
+			ret = -EINVAL;
+			goto done;
+		}
+
+		size = xmap->menu_count * sizeof(*map->menu_info);
+		map->menu_info = kmalloc(size, GFP_KERNEL);
+		if (map->menu_info == NULL) {
+			ret = -ENOMEM;
+			goto done;
+		}
+
+		if (copy_from_user(map->menu_info, xmap->menu_info, size)) {
+			ret = -EFAULT;
+			goto done;
+		}
+
+		map->menu_count = xmap->menu_count;
+		break;
+
+	default:
+		ret = -EINVAL;
+		goto done;
+	}
+
+	ret = uvc_ctrl_add_mapping(map);
+
+done:
+	if (ret < 0) {
+		kfree(map->menu_info);
+		kfree(map);
+	}
+
+	return ret;
+}
+
 /* ------------------------------------------------------------------------
  * V4L2 interface
  */
@@ -974,7 +1039,8 @@ static long uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
 		info->flags = xinfo->flags;
 
 		info->flags |= UVC_CONTROL_GET_MIN | UVC_CONTROL_GET_MAX |
-				UVC_CONTROL_GET_RES | UVC_CONTROL_GET_DEF;
+			       UVC_CONTROL_GET_RES | UVC_CONTROL_GET_DEF |
+			       UVC_CONTROL_EXTENSION;
 
 		ret = uvc_ctrl_add_info(info);
 		if (ret < 0)
@@ -982,32 +1048,12 @@ static long uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
 		break;
 	}
 
+	case UVCIOC_CTRL_MAP_OLD:
 	case UVCIOC_CTRL_MAP:
-	{
-		struct uvc_xu_control_mapping *xmap = arg;
-		struct uvc_control_mapping *map;
-
 		if (!capable(CAP_SYS_ADMIN))
 			return -EPERM;
 
-		map = kzalloc(sizeof *map, GFP_KERNEL);
-		if (map == NULL)
-			return -ENOMEM;
-
-		map->id = xmap->id;
-		memcpy(map->name, xmap->name, sizeof map->name);
-		memcpy(map->entity, xmap->entity, sizeof map->entity);
-		map->selector = xmap->selector;
-		map->size = xmap->size;
-		map->offset = xmap->offset;
-		map->v4l2_type = xmap->v4l2_type;
-		map->data_type = xmap->data_type;
-
-		ret = uvc_ctrl_add_mapping(map);
-		if (ret < 0)
-			kfree(map);
-		break;
-	}
+		return uvc_ioctl_ctrl_map(arg, cmd == UVCIOC_CTRL_MAP_OLD);
 
 	case UVCIOC_CTRL_GET:
 		return uvc_xu_ctrl_query(chain, arg, 0);

drivers/media/video/uvc/uvcvideo.h

@@ -27,6 +27,8 @@
 #define UVC_CONTROL_RESTORE	(1 << 6)
 /* Control can be updated by the camera. */
 #define UVC_CONTROL_AUTO_UPDATE	(1 << 7)
+/* Control is an extension unit control. */
+#define UVC_CONTROL_EXTENSION	(1 << 8)
 
 #define UVC_CONTROL_GET_RANGE	(UVC_CONTROL_GET_CUR | UVC_CONTROL_GET_MIN | \
 				 UVC_CONTROL_GET_MAX | UVC_CONTROL_GET_RES | \
@@ -40,6 +42,15 @@ struct uvc_xu_control_info {
 	__u32 flags;
 };
 
+struct uvc_menu_info {
+	__u32 value;
+	__u8 name[32];
+};
+
+struct uvc_xu_control_mapping_old {
+	__u8 reserved[64];
+};
+
 struct uvc_xu_control_mapping {
 	__u32 id;
 	__u8 name[32];
@@ -50,6 +61,11 @@ struct uvc_xu_control_mapping {
 	__u8 offset;
 	enum v4l2_ctrl_type v4l2_type;
 	__u32 data_type;
+
+	struct uvc_menu_info __user *menu_info;
+	__u32 menu_count;
+
+	__u32 reserved[4];
 };
 
 struct uvc_xu_control {
@@ -60,6 +76,7 @@ struct uvc_xu_control {
 };
 
 #define UVCIOC_CTRL_ADD		_IOW('U', 1, struct uvc_xu_control_info)
+#define UVCIOC_CTRL_MAP_OLD	_IOWR('U', 2, struct uvc_xu_control_mapping_old)
 #define UVCIOC_CTRL_MAP		_IOWR('U', 2, struct uvc_xu_control_mapping)
 #define UVCIOC_CTRL_GET		_IOWR('U', 3, struct uvc_xu_control)
 #define UVCIOC_CTRL_SET		_IOW('U', 4, struct uvc_xu_control)
@@ -198,11 +215,6 @@ struct uvc_streaming_control {
 	__u8  bMaxVersion;
 };
 
-struct uvc_menu_info {
-	__u32 value;
-	__u8 name[32];
-};
-
 struct uvc_control_info {
 	struct list_head list;
 	struct list_head mappings;
@@ -625,6 +637,7 @@ extern int uvc_ctrl_init_device(struct uvc_device *dev);
 extern void uvc_ctrl_cleanup_device(struct uvc_device *dev);
 extern int uvc_ctrl_resume_device(struct uvc_device *dev);
 extern void uvc_ctrl_init(void);
+extern void uvc_ctrl_cleanup(void);
 
 extern int uvc_ctrl_begin(struct uvc_video_chain *chain);
 extern int __uvc_ctrl_commit(struct uvc_video_chain *chain, int rollback);