include/media/media-dev-allocator.h

0001 /* SPDX-License-Identifier: GPL-2.0+ */
0002 /*
0003  * media-dev-allocator.h - Media Controller Device Allocator API
0004  *
0005  * Copyright (c) 2019 Shuah Khan <shuah@kernel.org>
0006  *
0007  * Credits: Suggested by Laurent Pinchart <laurent.pinchart@ideasonboard.com>
0008  */
0009
0010 /*
0011  * This file adds a global ref-counted Media Controller Device Instance API.
0012  * A system wide global media device list is managed and each media device
0013  * includes a kref count. The last put on the media device releases the media
0014  * device instance.
0015  */
0016
0017 #ifndef _MEDIA_DEV_ALLOCATOR_H
0018 #define _MEDIA_DEV_ALLOCATOR_H
0019
0020 struct usb_device;
0021
0022 #if defined(CONFIG_MEDIA_CONTROLLER) && IS_ENABLED(CONFIG_USB)
0023 /**
0024  * media_device_usb_allocate() - Allocate and return struct &media device
0025  *
0026  * @udev:       struct &usb_device pointer
0027  * @module_name:    should be filled with %KBUILD_MODNAME
0028  * @owner:      struct module pointer %THIS_MODULE for the driver.
0029  *          %THIS_MODULE is null for a built-in driver.
0030  *          It is safe even when %THIS_MODULE is null.
0031  *
0032  * This interface should be called to allocate a Media Device when multiple
0033  * drivers share usb_device and the media device. This interface allocates
0034  * &media_device structure and calls media_device_usb_init() to initialize
0035  * it.
0036  *
0037  */
0038 struct media_device *media_device_usb_allocate(struct usb_device *udev,
0039                            const char *module_name,
0040                            struct module *owner);
0041 /**
0042  * media_device_delete() - Release media device. Calls kref_put().
0043  *
0044  * @mdev:       struct &media_device pointer
0045  * @module_name:    should be filled with %KBUILD_MODNAME
0046  * @owner:      struct module pointer %THIS_MODULE for the driver.
0047  *          %THIS_MODULE is null for a built-in driver.
0048  *          It is safe even when %THIS_MODULE is null.
0049  *
0050  * This interface should be called to put Media Device Instance kref.
0051  */
0052 void media_device_delete(struct media_device *mdev, const char *module_name,
0053              struct module *owner);
0054 #else
0055 static inline struct media_device *media_device_usb_allocate(
0056             struct usb_device *udev, const char *module_name,
0057             struct module *owner)
0058             { return NULL; }
0059 static inline void media_device_delete(
0060             struct media_device *mdev, const char *module_name,
0061             struct module *owner) { }
0062 #endif /* CONFIG_MEDIA_CONTROLLER && CONFIG_USB */
0063 #endif /* _MEDIA_DEV_ALLOCATOR_H */