1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3 * media-dev-allocator.h - Media Controller Device Allocator API
4 *
5 * Copyright (c) 2019 Shuah Khan <shuah@kernel.org>
6 *
7 * Credits: Suggested by Laurent Pinchart <laurent.pinchart@ideasonboard.com>
8 */
9
10 /*
11 * This file adds a global ref-counted Media Controller Device Instance API.
12 * A system wide global media device list is managed and each media device
13 * includes a kref count. The last put on the media device releases the media
14 * device instance.
15 */
16
17 #ifndef _MEDIA_DEV_ALLOCATOR_H
18 #define _MEDIA_DEV_ALLOCATOR_H
19
20 struct usb_device;
21
22 #if defined(CONFIG_MEDIA_CONTROLLER) && IS_ENABLED(CONFIG_USB)
23 /**
24 * media_device_usb_allocate() - Allocate and return struct &media device
25 *
26 * @udev: struct &usb_device pointer
27 * @module_name: should be filled with %KBUILD_MODNAME
28 * @owner: struct module pointer %THIS_MODULE for the driver.
29 * %THIS_MODULE is null for a built-in driver.
30 * It is safe even when %THIS_MODULE is null.
31 *
32 * This interface should be called to allocate a Media Device when multiple
33 * drivers share usb_device and the media device. This interface allocates
34 * &media_device structure and calls media_device_usb_init() to initialize
35 * it.
36 *
37 */
38 struct media_device *media_device_usb_allocate(struct usb_device *udev,
39 const char *module_name,
40 struct module *owner);
41 /**
42 * media_device_delete() - Release media device. Calls kref_put().
43 *
44 * @mdev: struct &media_device pointer
45 * @module_name: should be filled with %KBUILD_MODNAME
46 * @owner: struct module pointer %THIS_MODULE for the driver.
47 * %THIS_MODULE is null for a built-in driver.
48 * It is safe even when %THIS_MODULE is null.
49 *
50 * This interface should be called to put Media Device Instance kref.
51 */
52 void media_device_delete(struct media_device *mdev, const char *module_name,
53 struct module *owner);
54 #else
media_device_usb_allocate(struct usb_device * udev,const char * module_name,struct module * owner)55 static inline struct media_device *media_device_usb_allocate(
56 struct usb_device *udev, const char *module_name,
57 struct module *owner)
58 { return NULL; }
media_device_delete(struct media_device * mdev,const char * module_name,struct module * owner)59 static inline void media_device_delete(
60 struct media_device *mdev, const char *module_name,
61 struct module *owner) { }
62 #endif /* CONFIG_MEDIA_CONTROLLER && CONFIG_USB */
63 #endif /* _MEDIA_DEV_ALLOCATOR_H */
64