linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * Media device request objects

 *

 * Copyright 2018 Cisco Systems, Inc. and/or its affiliates. All rights reserved.

 * Copyright (C) 2018 Intel Corporation

 *

 * Author: Hans Verkuil <hans.verkuil@cisco.com>

 * Author: Sakari Ailus <sakari.ailus@linux.intel.com>

 */

​

#ifndef MEDIA_REQUEST_H

#define MEDIA_REQUEST_H

​

#include <linux/list.h>

#include <linux/slab.h>

#include <linux/spinlock.h>

#include <linux/refcount.h>

​

#include <media/media-device.h>

​

/**

 * enum media_request_state - media request state

 *

 * @MEDIA_REQUEST_STATE_IDLE:       Idle

 * @MEDIA_REQUEST_STATE_VALIDATING: Validating the request, no state changes

 *                  allowed

 * @MEDIA_REQUEST_STATE_QUEUED:     Queued

 * @MEDIA_REQUEST_STATE_COMPLETE:   Completed, the request is done

 * @MEDIA_REQUEST_STATE_CLEANING:   Cleaning, the request is being re-inited

 * @MEDIA_REQUEST_STATE_UPDATING:   The request is being updated, i.e.

 *                  request objects are being added,

 *                  modified or removed

 * @NR_OF_MEDIA_REQUEST_STATE:      The number of media request states, used

 *                  internally for sanity check purposes

 */

enum media_request_state {

    MEDIA_REQUEST_STATE_IDLE,

    MEDIA_REQUEST_STATE_VALIDATING,

    MEDIA_REQUEST_STATE_QUEUED,

    MEDIA_REQUEST_STATE_COMPLETE,

    MEDIA_REQUEST_STATE_CLEANING,

    MEDIA_REQUEST_STATE_UPDATING,

    NR_OF_MEDIA_REQUEST_STATE,

};

​

struct media_request_object;

​

/**

 * struct media_request - Media device request

 * @mdev: Media device this request belongs to

 * @kref: Reference count

 * @debug_str: Prefix for debug messages (process name:fd)

 * @state: The state of the request

 * @updating_count: count the number of request updates that are in progress

 * @access_count: count the number of request accesses that are in progress

 * @objects: List of @struct media_request_object request objects

 * @num_incomplete_objects: The number of incomplete objects in the request

 * @poll_wait: Wait queue for poll

 * @lock: Serializes access to this struct

 */

struct media_request {

    struct media_device *mdev;

    struct kref kref;

    char debug_str[TASK_COMM_LEN + 11];

    enum media_request_state state;

    unsigned int updating_count;

    unsigned int access_count;

    struct list_head objects;

    unsigned int num_incomplete_objects;

    wait_queue_head_t poll_wait;

    spinlock_t lock;

};

​

#ifdef CONFIG_MEDIA_CONTROLLER

​

/**

 * media_request_lock_for_access - Lock the request to access its objects

 *

 * @req: The media request

 *

 * Use before accessing a completed request. A reference to the request must

 * be held during the access. This usually takes place automatically through

 * a file handle. Use @media_request_unlock_for_access when done.

 */

static inline int __must_check

media_request_lock_for_access(struct media_request *req)

{

    unsigned long flags;

    int ret = -EBUSY;

​

    spin_lock_irqsave(&req->lock, flags);