@@ -3,7 +3,8 @@
# Makefile for the kernel multimedia device drivers.
#
-media-objs := media-device.o media-devnode.o media-entity.o
+media-objs := media-device.o media-devnode.o media-entity.o \
+ media-request.o
#
# I2C drivers should come before other drivers, otherwise they'll fail
@@ -29,6 +29,7 @@
#include <media/media-device.h>
#include <media/media-devnode.h>
#include <media/media-entity.h>
+#include <media/media-request.h>
#ifdef CONFIG_MEDIA_CONTROLLER
@@ -374,6 +375,15 @@ static long media_device_get_topology(struct media_device *mdev, void *arg)
return ret;
}
+static long media_device_request_alloc(struct media_device *mdev,
+ struct media_request_alloc *alloc)
+{
+ if (!mdev->ops || !mdev->ops->req_validate || !mdev->ops->req_queue)
+ return -ENOTTY;
+
+ return media_request_alloc(mdev, alloc);
+}
+
static long copy_arg_from_user(void *karg, void __user *uarg, unsigned int cmd)
{
/* All media IOCTLs are _IOWR() */
@@ -422,6 +432,7 @@ static const struct media_ioctl_info ioctl_info[] = {
MEDIA_IOC(ENUM_LINKS, media_device_enum_links, MEDIA_IOC_FL_GRAPH_MUTEX),
MEDIA_IOC(SETUP_LINK, media_device_setup_link, MEDIA_IOC_FL_GRAPH_MUTEX),
MEDIA_IOC(G_TOPOLOGY, media_device_get_topology, MEDIA_IOC_FL_GRAPH_MUTEX),
+ MEDIA_IOC(REQUEST_ALLOC, media_device_request_alloc, 0),
};
static long media_device_ioctl(struct file *filp, unsigned int cmd,
@@ -694,6 +705,8 @@ void media_device_init(struct media_device *mdev)
INIT_LIST_HEAD(&mdev->pads);
INIT_LIST_HEAD(&mdev->links);
INIT_LIST_HEAD(&mdev->entity_notify);
+
+ mutex_init(&mdev->req_queue_mutex);
mutex_init(&mdev->graph_mutex);
ida_init(&mdev->entity_internal_idx);
@@ -707,6 +720,7 @@ void media_device_cleanup(struct media_device *mdev)
mdev->entity_internal_idx_max = 0;
media_graph_walk_cleanup(&mdev->pm_count_walk);
mutex_destroy(&mdev->graph_mutex);
+ mutex_destroy(&mdev->req_queue_mutex);
}
EXPORT_SYMBOL_GPL(media_device_cleanup);
new file mode 100644
@@ -0,0 +1,423 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Media device request objects
+ *
+ * Copyright 2018 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
+ * Copyright (C) 2018 Intel Corporation
+ * Copyright (C) 2018 Google, Inc.
+ *
+ * Author: Hans Verkuil <hans.verkuil@cisco.com>
+ * Author: Sakari Ailus <sakari.ailus@linux.intel.com>
+ */
+
+#include <linux/anon_inodes.h>
+#include <linux/file.h>
+#include <linux/refcount.h>
+
+#include <media/media-device.h>
+#include <media/media-request.h>
+
+static const char * const request_state[] = {
+ [MEDIA_REQUEST_STATE_IDLE] = "idle",
+ [MEDIA_REQUEST_STATE_VALIDATING] = "validating",
+ [MEDIA_REQUEST_STATE_QUEUED] = "queued",
+ [MEDIA_REQUEST_STATE_COMPLETE] = "complete",
+ [MEDIA_REQUEST_STATE_CLEANING] = "cleaning",
+ [MEDIA_REQUEST_STATE_UPDATING] = "updating",
+};
+
+static const char *
+media_request_state_str(enum media_request_state state)
+{
+ BUILD_BUG_ON(ARRAY_SIZE(request_state) != NR_OF_MEDIA_REQUEST_STATE);
+
+ if (WARN_ON(state >= ARRAY_SIZE(request_state)))
+ return "invalid";
+ return request_state[state];
+}
+
+static void media_request_clean(struct media_request *req)
+{
+ struct media_request_object *obj, *obj_safe;
+
+ /* Just a sanity check. No other code path is allowed to change this. */
+ WARN_ON(req->state != MEDIA_REQUEST_STATE_CLEANING);
+ WARN_ON(req->updating_count);
+
+ list_for_each_entry_safe(obj, obj_safe, &req->objects, list) {
+ media_request_object_unbind(obj);
+ media_request_object_put(obj);
+ }
+
+ req->updating_count = 0;
+ WARN_ON(req->num_incomplete_objects);
+ req->num_incomplete_objects = 0;
+ wake_up_interruptible_all(&req->poll_wait);
+}
+
+static void media_request_release(struct kref *kref)
+{
+ struct media_request *req =
+ container_of(kref, struct media_request, kref);
+ struct media_device *mdev = req->mdev;
+
+ dev_dbg(mdev->dev, "request: release %s\n", req->debug_str);
+
+ /* No other users, no need for a spinlock */
+ req->state = MEDIA_REQUEST_STATE_CLEANING;
+
+ media_request_clean(req);
+
+ if (mdev->ops->req_free)
+ mdev->ops->req_free(req);
+ else
+ kfree(req);
+}
+
+void media_request_put(struct media_request *req)
+{
+ kref_put(&req->kref, media_request_release);
+}
+EXPORT_SYMBOL_GPL(media_request_put);
+
+static int media_request_close(struct inode *inode, struct file *filp)
+{
+ struct media_request *req = filp->private_data;
+
+ media_request_put(req);
+ return 0;
+}
+
+static unsigned int media_request_poll(struct file *filp,
+ struct poll_table_struct *wait)
+{
+ struct media_request *req = filp->private_data;
+ unsigned long flags;
+ unsigned int ret = 0;
+
+ if (!(poll_requested_events(wait) & POLLPRI))
+ return 0;
+
+ spin_lock_irqsave(&req->lock, flags);
+ if (req->state == MEDIA_REQUEST_STATE_COMPLETE) {
+ ret = POLLPRI;
+ goto unlock;
+ }
+ if (req->state != MEDIA_REQUEST_STATE_QUEUED) {
+ ret = POLLERR;
+ goto unlock;
+ }
+
+ poll_wait(filp, &req->poll_wait, wait);
+
+unlock:
+ spin_unlock_irqrestore(&req->lock, flags);
+ return ret;
+}
+
+static long media_request_ioctl_queue(struct media_request *req)
+{
+ struct media_device *mdev = req->mdev;
+ enum media_request_state state;
+ unsigned long flags;
+ int ret;
+
+ dev_dbg(mdev->dev, "request: queue %s\n", req->debug_str);
+
+ /*
+ * Ensure the request that is validated will be the one that gets queued
+ * next by serialising the queueing process. This mutex is also used
+ * to serialize with canceling a vb2 queue and with setting values such
+ * as controls in a request.
+ */
+ mutex_lock(&mdev->req_queue_mutex);
+
+ media_request_get(req);
+
+ spin_lock_irqsave(&req->lock, flags);
+ if (req->state == MEDIA_REQUEST_STATE_IDLE)
+ req->state = MEDIA_REQUEST_STATE_VALIDATING;
+ state = req->state;
+ spin_unlock_irqrestore(&req->lock, flags);
+ if (state != MEDIA_REQUEST_STATE_VALIDATING) {
+ dev_dbg(mdev->dev,
+ "request: unable to queue %s, request in state %s\n",
+ req->debug_str, media_request_state_str(state));
+ mutex_unlock(&mdev->req_queue_mutex);
+ return -EBUSY;
+ }
+
+ ret = mdev->ops->req_validate(req);
+
+ /*
+ * If the req_validate was successful, then we mark the state as QUEUED
+ * and call req_queue. The reason we set the state first is that this
+ * allows req_queue to unbind or complete the queued objects in case
+ * they are immediately 'consumed'. State changes from QUEUED to another
+ * state can only happen if either the driver changes the state or if
+ * the user cancels the vb2 queue. The driver can only change the state
+ * after each object is queued through the req_queue op (and note that
+ * that op cannot fail), so setting the state to QUEUED up front is
+ * safe.
+ *
+ * The other reason for changing the state is if the vb2 queue is
+ * canceled, and that uses the req_queue_mutex which is still locked
+ * while req_queue is called, so that's safe as well.
+ */
+ spin_lock_irqsave(&req->lock, flags);
+ req->state = ret ? MEDIA_REQUEST_STATE_IDLE
+ : MEDIA_REQUEST_STATE_QUEUED;
+ spin_unlock_irqrestore(&req->lock, flags);
+
+ if (!ret)
+ mdev->ops->req_queue(req);
+
+ mutex_unlock(&mdev->req_queue_mutex);
+
+ if (ret) {
+ dev_dbg(mdev->dev, "request: can't queue %s (%d)\n",
+ req->debug_str, ret);
+ media_request_put(req);
+ }
+
+ return ret;
+}
+
+static long media_request_ioctl_reinit(struct media_request *req)
+{
+ struct media_device *mdev = req->mdev;
+ unsigned long flags;
+
+ spin_lock_irqsave(&req->lock, flags);
+ if (req->state != MEDIA_REQUEST_STATE_IDLE &&
+ req->state != MEDIA_REQUEST_STATE_COMPLETE) {
+ dev_dbg(mdev->dev,
+ "request: %s not in idle or complete state, cannot reinit\n",
+ req->debug_str);
+ spin_unlock_irqrestore(&req->lock, flags);
+ return -EBUSY;
+ }
+ req->state = MEDIA_REQUEST_STATE_CLEANING;
+ spin_unlock_irqrestore(&req->lock, flags);
+
+ media_request_clean(req);
+
+ spin_lock_irqsave(&req->lock, flags);
+ req->state = MEDIA_REQUEST_STATE_IDLE;
+ spin_unlock_irqrestore(&req->lock, flags);
+
+ return 0;
+}
+
+static long media_request_ioctl(struct file *filp, unsigned int cmd,
+ unsigned long arg)
+{
+ struct media_request *req = filp->private_data;
+
+ switch (cmd) {
+ case MEDIA_REQUEST_IOC_QUEUE:
+ return media_request_ioctl_queue(req);
+ case MEDIA_REQUEST_IOC_REINIT:
+ return media_request_ioctl_reinit(req);
+ default:
+ return -ENOIOCTLCMD;
+ }
+}
+
+static const struct file_operations request_fops = {
+ .owner = THIS_MODULE,
+ .poll = media_request_poll,
+ .unlocked_ioctl = media_request_ioctl,
+ .release = media_request_close,
+};
+
+int media_request_alloc(struct media_device *mdev,
+ struct media_request_alloc *alloc)
+{
+ struct media_request *req;
+ struct file *filp;
+ char comm[TASK_COMM_LEN];
+ int fd;
+ int ret;
+
+ /* Either both are NULL or both are non-NULL */
+ if (WARN_ON(!mdev->ops->req_alloc ^ !mdev->ops->req_free))
+ return -ENOMEM;
+
+ fd = get_unused_fd_flags(O_CLOEXEC);
+ if (fd < 0)
+ return fd;
+
+ filp = anon_inode_getfile("request", &request_fops, NULL, O_CLOEXEC);
+ if (IS_ERR(filp)) {
+ ret = PTR_ERR(filp);
+ goto err_put_fd;
+ }
+
+ if (mdev->ops->req_alloc)
+ req = mdev->ops->req_alloc(mdev);
+ else
+ req = kzalloc(sizeof(*req), GFP_KERNEL);
+ if (!req) {
+ ret = -ENOMEM;
+ goto err_fput;
+ }
+
+ filp->private_data = req;
+ req->mdev = mdev;
+ req->state = MEDIA_REQUEST_STATE_IDLE;
+ req->num_incomplete_objects = 0;
+ kref_init(&req->kref);
+ INIT_LIST_HEAD(&req->objects);
+ spin_lock_init(&req->lock);
+ init_waitqueue_head(&req->poll_wait);
+ req->updating_count = 0;
+
+ alloc->fd = fd;
+
+ get_task_comm(comm, current);
+ snprintf(req->debug_str, sizeof(req->debug_str), "%s:%d",
+ comm, fd);
+ dev_dbg(mdev->dev, "request: allocated %s\n", req->debug_str);
+
+ fd_install(fd, filp);
+
+ return 0;
+
+err_fput:
+ fput(filp);
+
+err_put_fd:
+ put_unused_fd(fd);
+
+ return ret;
+}
+
+static void media_request_object_release(struct kref *kref)
+{
+ struct media_request_object *obj =
+ container_of(kref, struct media_request_object, kref);
+ struct media_request *req = obj->req;
+
+ if (WARN_ON(req))
+ media_request_object_unbind(obj);
+ obj->ops->release(obj);
+}
+
+void media_request_object_put(struct media_request_object *obj)
+{
+ kref_put(&obj->kref, media_request_object_release);
+}
+EXPORT_SYMBOL_GPL(media_request_object_put);
+
+void media_request_object_init(struct media_request_object *obj)
+{
+ obj->ops = NULL;
+ obj->req = NULL;
+ obj->priv = NULL;
+ obj->completed = false;
+ INIT_LIST_HEAD(&obj->list);
+ kref_init(&obj->kref);
+}
+EXPORT_SYMBOL_GPL(media_request_object_init);
+
+int media_request_object_bind(struct media_request *req,
+ const struct media_request_object_ops *ops,
+ void *priv,
+ struct media_request_object *obj)
+{
+ unsigned long flags;
+ int ret = -EBUSY;
+
+ if (WARN_ON(!ops->release))
+ return -EPERM;
+
+ spin_lock_irqsave(&req->lock, flags);
+
+ if (WARN_ON(req->state != MEDIA_REQUEST_STATE_UPDATING))
+ goto unlock;
+
+ obj->req = req;
+ obj->ops = ops;
+ obj->priv = priv;
+
+ list_add_tail(&obj->list, &req->objects);
+ req->num_incomplete_objects++;
+ ret = 0;
+
+unlock:
+ spin_unlock_irqrestore(&req->lock, flags);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(media_request_object_bind);
+
+void media_request_object_unbind(struct media_request_object *obj)
+{
+ struct media_request *req = obj->req;
+ unsigned long flags;
+ bool completed = false;
+
+ if (WARN_ON(!req))
+ return;
+
+ spin_lock_irqsave(&req->lock, flags);
+ list_del(&obj->list);
+ obj->req = NULL;
+
+ if (req->state == MEDIA_REQUEST_STATE_COMPLETE)
+ goto unlock;
+
+ if (WARN_ON(req->state == MEDIA_REQUEST_STATE_VALIDATING))
+ goto unlock;
+
+ if (req->state == MEDIA_REQUEST_STATE_CLEANING) {
+ if (!obj->completed)
+ req->num_incomplete_objects--;
+ goto unlock;
+ }
+
+ if (WARN_ON(!req->num_incomplete_objects))
+ goto unlock;
+
+ req->num_incomplete_objects--;
+ if (req->state == MEDIA_REQUEST_STATE_QUEUED &&
+ !req->num_incomplete_objects) {
+ req->state = MEDIA_REQUEST_STATE_COMPLETE;
+ completed = true;
+ wake_up_interruptible_all(&req->poll_wait);
+ }
+
+unlock:
+ spin_unlock_irqrestore(&req->lock, flags);
+ if (obj->ops->unbind)
+ obj->ops->unbind(obj);
+ if (completed)
+ media_request_put(req);
+}
+EXPORT_SYMBOL_GPL(media_request_object_unbind);
+
+void media_request_object_complete(struct media_request_object *obj)
+{
+ struct media_request *req = obj->req;
+ unsigned long flags;
+ bool completed = false;
+
+ spin_lock_irqsave(&req->lock, flags);
+ if (obj->completed)
+ goto unlock;
+ obj->completed = true;
+ if (WARN_ON(!req->num_incomplete_objects) ||
+ WARN_ON(req->state != MEDIA_REQUEST_STATE_QUEUED))
+ goto unlock;
+
+ if (!--req->num_incomplete_objects) {
+ req->state = MEDIA_REQUEST_STATE_COMPLETE;
+ wake_up_interruptible_all(&req->poll_wait);
+ completed = true;
+ }
+unlock:
+ spin_unlock_irqrestore(&req->lock, flags);
+ if (completed)
+ media_request_put(req);
+}
+EXPORT_SYMBOL_GPL(media_request_object_complete);
@@ -27,6 +27,7 @@
struct ida;
struct device;
+struct media_device;
/**
* struct media_entity_notify - Media Entity Notify
@@ -50,10 +51,26 @@ struct media_entity_notify {
* struct media_device_ops - Media device operations
* @link_notify: Link state change notification callback. This callback is
* called with the graph_mutex held.
+ * @req_alloc: Allocate a request. Set this if you need to allocate a struct
+ * larger then struct media_request. @req_alloc and @req_free must
+ * either both be set or both be NULL.
+ * @req_free: Free a request. Set this if @req_alloc was set as well, leave
+ * to NULL otherwise.
+ * @req_validate: Validate a request, but do not queue yet. The req_queue_mutex
+ * lock is held when this op is called.
+ * @req_queue: Queue a validated request, cannot fail. If something goes
+ * wrong when queueing this request then it should be marked
+ * as such internally in the driver and any related buffers
+ * must eventually return to vb2 with state VB2_BUF_STATE_ERROR.
+ * The req_queue_mutex lock is held when this op is called.
*/
struct media_device_ops {
int (*link_notify)(struct media_link *link, u32 flags,
unsigned int notification);
+ struct media_request *(*req_alloc)(struct media_device *mdev);
+ void (*req_free)(struct media_request *req);
+ int (*req_validate)(struct media_request *req);
+ void (*req_queue)(struct media_request *req);
};
/**
@@ -88,6 +105,8 @@ struct media_device_ops {
* @disable_source: Disable Source Handler function pointer
*
* @ops: Operation handler callbacks
+ * @req_queue_mutex: Serialise the MEDIA_REQUEST_IOC_QUEUE ioctl w.r.t.
+ * other operations that stop or start streaming.
*
* This structure represents an abstract high-level media device. It allows easy
* access to entities and provides basic media device-level support. The
@@ -158,6 +177,8 @@ struct media_device {
void (*disable_source)(struct media_entity *entity);
const struct media_device_ops *ops;
+
+ struct mutex req_queue_mutex;
};
/* We don't need to include pci.h or usb.h here */
new file mode 100644
@@ -0,0 +1,327 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * 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
+ * @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;
+ struct list_head objects;
+ unsigned int num_incomplete_objects;
+ struct wait_queue_head poll_wait;
+ spinlock_t lock;
+};
+
+#ifdef CONFIG_MEDIA_CONTROLLER
+
+/**
+ * media_request_lock_for_update - Lock the request for updating its objects
+ *
+ * @req: The media request
+ *
+ * Use before updating a request, i.e. adding, modifying or removing a request
+ * object in it. A reference to the request must be held during the update. This
+ * usually takes place automatically through a file handle. Use
+ * @media_request_unlock_for_update when done.
+ */
+static inline int __must_check
+media_request_lock_for_update(struct media_request *req)
+{
+ unsigned long flags;
+ int ret = 0;
+
+ spin_lock_irqsave(&req->lock, flags);
+ if (req->state == MEDIA_REQUEST_STATE_IDLE ||
+ req->state == MEDIA_REQUEST_STATE_UPDATING) {
+ req->state = MEDIA_REQUEST_STATE_UPDATING;
+ req->updating_count++;
+ } else {
+ ret = -EBUSY;
+ }
+ spin_unlock_irqrestore(&req->lock, flags);
+
+ return ret;
+}
+
+/**
+ * media_request_unlock_for_update - Unlock a request previously locked for
+ * update
+ *
+ * @req: The media request
+ *
+ * Unlock a request that has previously been locked using
+ * @media_request_lock_for_update.
+ */
+static inline void media_request_unlock_for_update(struct media_request *req)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&req->lock, flags);
+ WARN_ON(req->updating_count <= 0);
+ if (!--req->updating_count)
+ req->state = MEDIA_REQUEST_STATE_IDLE;
+ spin_unlock_irqrestore(&req->lock, flags);
+}
+
+/**
+ * media_request_get - Get the media request
+ *
+ * @req: The media request
+ *
+ * Get the media request.
+ */
+static inline void media_request_get(struct media_request *req)
+{
+ kref_get(&req->kref);
+}
+
+/**
+ * media_request_put - Put the media request
+ *
+ * @req: The media request
+ *
+ * Put the media request. The media request will be released
+ * when the refcount reaches 0.
+ */
+void media_request_put(struct media_request *req);
+
+/**
+ * media_request_alloc - Allocate the media request
+ *
+ * @mdev: Media device this request belongs to
+ * @alloc: Store the request's file descriptor in this struct
+ *
+ * Allocated the media request and put the fd in @alloc->fd.
+ */
+int media_request_alloc(struct media_device *mdev,
+ struct media_request_alloc *alloc);
+
+#else
+
+static inline void media_request_get(struct media_request *req)
+{
+}
+
+static inline void media_request_put(struct media_request *req)
+{
+}
+
+#endif
+
+/**
+ * struct media_request_object_ops - Media request object operations
+ * @prepare: Validate and prepare the request object, optional.
+ * @unprepare: Unprepare the request object, optional.
+ * @queue: Queue the request object, optional.
+ * @unbind: Unbind the request object, optional.
+ * @release: Release the request object, required.
+ */
+struct media_request_object_ops {
+ int (*prepare)(struct media_request_object *object);
+ void (*unprepare)(struct media_request_object *object);
+ void (*queue)(struct media_request_object *object);
+ void (*unbind)(struct media_request_object *object);
+ void (*release)(struct media_request_object *object);
+};
+
+/**
+ * struct media_request_object - An opaque object that belongs to a media
+ * request
+ *
+ * @ops: object's operations
+ * @priv: object's priv pointer
+ * @req: the request this object belongs to (can be NULL)
+ * @list: List entry of the object for @struct media_request
+ * @kref: Reference count of the object, acquire before releasing req->lock
+ * @completed: If true, then this object was completed.
+ *
+ * An object related to the request. This struct is always embedded in
+ * another struct that contains the actual data for this request object.
+ */
+struct media_request_object {
+ const struct media_request_object_ops *ops;
+ void *priv;
+ struct media_request *req;
+ struct list_head list;
+ struct kref kref;
+ bool completed;
+};
+
+#ifdef CONFIG_MEDIA_CONTROLLER
+
+/**
+ * media_request_object_get - Get a media request object
+ *
+ * @obj: The object
+ *
+ * Get a media request object.
+ */
+static inline void media_request_object_get(struct media_request_object *obj)
+{
+ kref_get(&obj->kref);
+}
+
+/**
+ * media_request_object_put - Put a media request object
+ *
+ * @obj: The object
+ *
+ * Put a media request object. Once all references are gone, the
+ * object's memory is released.
+ */
+void media_request_object_put(struct media_request_object *obj);
+
+/**
+ * media_request_object_init - Initialise a media request object
+ *
+ * @obj: The object
+ *
+ * Initialise a media request object. The object will be released using the
+ * release callback of the ops once it has no references (this function
+ * initialises references to one).
+ */
+void media_request_object_init(struct media_request_object *obj);
+
+/**
+ * media_request_object_bind - Bind a media request object to a request
+ *
+ * @req: The media request
+ * @ops: The object ops for this object
+ * @priv: A driver-specific priv pointer associated with this object
+ * @obj: The object
+ *
+ * Bind this object to the request and set the ops and priv values of
+ * the object so it can be found later with media_request_object_find().
+ *
+ * Every bound object must be unbound or completed by the kernel at some
+ * point in time, otherwise the request will never complete. When the
+ * request is released all completed objects will be unbound by the
+ * request core code.
+ */
+int media_request_object_bind(struct media_request *req,
+ const struct media_request_object_ops *ops,
+ void *priv,
+ struct media_request_object *obj);
+
+/**
+ * media_request_object_unbind - Unbind a media request object
+ *
+ * @obj: The object
+ *
+ * Unbind the media request object from the request.
+ */
+void media_request_object_unbind(struct media_request_object *obj);
+
+/**
+ * media_request_object_complete - Mark the media request object as complete
+ *
+ * @obj: The object
+ *
+ * Mark the media request object as complete. Only bound objects can
+ * be completed.
+ */
+void media_request_object_complete(struct media_request_object *obj);
+
+#else
+
+static inline int __must_check
+media_request_lock_for_update(struct media_request *req)
+{
+ return -EINVAL;
+}
+
+static inline void media_request_unlock_for_update(struct media_request *req)
+{
+}
+
+static inline void media_request_object_get(struct media_request_object *obj)
+{
+}
+
+static inline void media_request_object_put(struct media_request_object *obj)
+{
+}
+
+static inline void media_request_object_init(struct media_request_object *obj)
+{
+ obj->ops = NULL;
+ obj->req = NULL;
+}
+
+static inline int media_request_object_bind(struct media_request *req,
+ const struct media_request_object_ops *ops,
+ void *priv,
+ struct media_request_object *obj)
+{
+ return 0;
+}
+
+static inline void media_request_object_unbind(struct media_request_object *obj)
+{
+}
+
+static inline void media_request_object_complete(struct media_request_object *obj)
+{
+}
+
+#endif
+
+#endif