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torvalds
GitHub Repository: torvalds/linux
 Path: blob/master/include/media/media-dev-allocator.h
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/* SPDX-License-Identifier: GPL-2.0+ */

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/*

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 * media-dev-allocator.h - Media Controller Device Allocator API

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 *

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 * Copyright (c) 2019 Shuah Khan <[email protected]>

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 *

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 * Credits: Suggested by Laurent Pinchart <[email protected]>

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 */

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/*

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 * This file adds a global ref-counted Media Controller Device Instance API.

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 * A system wide global media device list is managed and each media device

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 * includes a kref count. The last put on the media device releases the media

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 * device instance.

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 */

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#ifndef _MEDIA_DEV_ALLOCATOR_H

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#define _MEDIA_DEV_ALLOCATOR_H

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struct usb_device;

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#if defined(CONFIG_MEDIA_CONTROLLER) && IS_ENABLED(CONFIG_USB)

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/**

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 * media_device_usb_allocate() - Allocate and return struct &media device

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 *

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 * @udev:		struct &usb_device pointer

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 * @module_name:	should be filled with %KBUILD_MODNAME

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 * @owner:		struct module pointer %THIS_MODULE for the driver.

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 *			%THIS_MODULE is null for a built-in driver.

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 *			It is safe even when %THIS_MODULE is null.

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 *

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 * This interface should be called to allocate a Media Device when multiple

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 * drivers share usb_device and the media device. This interface allocates

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 * &media_device structure and calls media_device_usb_init() to initialize

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 * it.

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 *

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 */

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struct media_device *media_device_usb_allocate(struct usb_device *udev,

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					       const char *module_name,

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					       struct module *owner);

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/**

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 * media_device_delete() - Release media device. Calls kref_put().

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 *

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 * @mdev:		struct &media_device pointer

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 * @module_name:	should be filled with %KBUILD_MODNAME

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 * @owner:		struct module pointer %THIS_MODULE for the driver.

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 *			%THIS_MODULE is null for a built-in driver.

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 *			It is safe even when %THIS_MODULE is null.

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 *

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 * This interface should be called to put Media Device Instance kref.

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 */

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void media_device_delete(struct media_device *mdev, const char *module_name,

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			 struct module *owner);

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#else

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static inline struct media_device *media_device_usb_allocate(

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			struct usb_device *udev, const char *module_name,

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			struct module *owner)

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			{ return NULL; }

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static inline void media_device_delete(

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			struct media_device *mdev, const char *module_name,

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			struct module *owner) { }

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#endif /* CONFIG_MEDIA_CONTROLLER && CONFIG_USB */

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#endif /* _MEDIA_DEV_ALLOCATOR_H */

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