LXR linux/include/media/media-dev-allocator.h

   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
  20struct usb_device;
  21
  22#if defined(CONFIG_MEDIA_CONTROLLER) && defined(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 */
  38struct 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 */
  52void media_device_delete(struct media_device *mdev, const char *module_name,
  53                         struct module *owner);
  54#else
  55static inline struct media_device *media_device_usb_allocate(
  56                        struct usb_device *udev, const char *module_name,
  57                        struct module *owner)
  58                        { return NULL; }
  59static 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