drivers/media/v4l2-core/v4l2-ctrls-request.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * V4L2 controls framework Request API implementation.
  *
  * Copyright (C) 2018-2021  Hans Verkuil <hverkuil-cisco@xs4all.nl>
  */

 #define pr_fmt(fmt) "v4l2-ctrls: " fmt

 #include <linux/export.h>
 #include <linux/slab.h>
 #include <media/v4l2-ctrls.h>
 #include <media/v4l2-dev.h>
 #include <media/v4l2-ioctl.h>

 #include "v4l2-ctrls-priv.h"

 /* Initialize the request-related fields in a control handler */
 void v4l2_ctrl_handler_init_request(struct v4l2_ctrl_handler *hdl)
 {
 	INIT_LIST_HEAD(&hdl->requests);
 	INIT_LIST_HEAD(&hdl->requests_queued);
 	hdl->request_is_queued = false;
 	media_request_object_init(&hdl->req_obj);
 }

 /* Free the request-related fields in a control handler */
 void v4l2_ctrl_handler_free_request(struct v4l2_ctrl_handler *hdl)
 {
 	struct v4l2_ctrl_handler *req, *next_req;

 	/*
 	 * Do nothing if this isn't the main handler or the main
 	 * handler is not used in any request.
 	 *
 	 * The main handler can be identified by having a NULL ops pointer in
 	 * the request object.
 	 */
 	if (hdl->req_obj.ops || list_empty(&hdl->requests))
 		return;

 	/*
 	 * If the main handler is freed and it is used by handler objects in
 	 * outstanding requests, then unbind and put those objects before
 	 * freeing the main handler.
 	 */
 	list_for_each_entry_safe(req, next_req, &hdl->requests, requests) {
 		media_request_object_unbind(&req->req_obj);
 		media_request_object_put(&req->req_obj);
 	}
 }

 static int v4l2_ctrl_request_clone(struct v4l2_ctrl_handler *hdl,
 				   const struct v4l2_ctrl_handler *from)
 {
 	struct v4l2_ctrl_ref *ref;
 	int err = 0;

 	if (WARN_ON(!hdl || hdl == from))
 		return -EINVAL;

 	if (hdl->error)
 		return hdl->error;

 	WARN_ON(hdl->lock != &hdl->_lock);

 	mutex_lock(from->lock);
 	list_for_each_entry(ref, &from->ctrl_refs, node) {
 		struct v4l2_ctrl *ctrl = ref->ctrl;
 		struct v4l2_ctrl_ref *new_ref;

 		/* Skip refs inherited from other devices */
 		if (ref->from_other_dev)
 			continue;
 		err = handler_new_ref(hdl, ctrl, &new_ref, false, true);
 		if (err)
 			break;
 	}
 	mutex_unlock(from->lock);
 	return err;
 }

 static void v4l2_ctrl_request_queue(struct media_request_object *obj)
 {
 	struct v4l2_ctrl_handler *hdl =
 		container_of(obj, struct v4l2_ctrl_handler, req_obj);
 	struct v4l2_ctrl_handler *main_hdl = obj->priv;

 	mutex_lock(main_hdl->lock);
 	list_add_tail(&hdl->requests_queued, &main_hdl->requests_queued);
 	hdl->request_is_queued = true;
 	mutex_unlock(main_hdl->lock);
 }

 static void v4l2_ctrl_request_unbind(struct media_request_object *obj)
 {
 	struct v4l2_ctrl_handler *hdl =
 		container_of(obj, struct v4l2_ctrl_handler, req_obj);
 	struct v4l2_ctrl_handler *main_hdl = obj->priv;

 	mutex_lock(main_hdl->lock);
 	list_del_init(&hdl->requests);
 	if (hdl->request_is_queued) {
 		list_del_init(&hdl->requests_queued);
 		hdl->request_is_queued = false;
 	}
 	mutex_unlock(main_hdl->lock);
 }

 static void v4l2_ctrl_request_release(struct media_request_object *obj)
 {
 	struct v4l2_ctrl_handler *hdl =
 		container_of(obj, struct v4l2_ctrl_handler, req_obj);

 	v4l2_ctrl_handler_free(hdl);
 	kfree(hdl);
 }

 static const struct media_request_object_ops req_ops = {
 	.queue = v4l2_ctrl_request_queue,
 	.unbind = v4l2_ctrl_request_unbind,
 	.release = v4l2_ctrl_request_release,
 };

 struct v4l2_ctrl_handler *v4l2_ctrl_request_hdl_find(struct media_request *req,
 						     struct v4l2_ctrl_handler *parent)
 {
 	struct media_request_object *obj;

 	if (WARN_ON(req->state != MEDIA_REQUEST_STATE_VALIDATING &&
 		    req->state != MEDIA_REQUEST_STATE_QUEUED))
 		return NULL;

 	obj = media_request_object_find(req, &req_ops, parent);
 	if (obj)
 		return container_of(obj, struct v4l2_ctrl_handler, req_obj);
 	return NULL;
 }
 EXPORT_SYMBOL_GPL(v4l2_ctrl_request_hdl_find);

 struct v4l2_ctrl *
 v4l2_ctrl_request_hdl_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id)
 {
 	struct v4l2_ctrl_ref *ref = find_ref_lock(hdl, id);

 	return (ref && ref->valid_p_req) ? ref->ctrl : NULL;
 }
 EXPORT_SYMBOL_GPL(v4l2_ctrl_request_hdl_ctrl_find);

 static int v4l2_ctrl_request_bind(struct media_request *req,
 				  struct v4l2_ctrl_handler *hdl,
 				  struct v4l2_ctrl_handler *from)
 {
 	int ret;

 	ret = v4l2_ctrl_request_clone(hdl, from);

 	if (!ret) {
 		ret = media_request_object_bind(req, &req_ops,
 						from, false, &hdl->req_obj);
 		if (!ret) {
 			mutex_lock(from->lock);
 			list_add_tail(&hdl->requests, &from->requests);
 			mutex_unlock(from->lock);
 		}
 	}
 	return ret;
 }

 static struct media_request_object *
 v4l2_ctrls_find_req_obj(struct v4l2_ctrl_handler *hdl,
 			struct media_request *req, bool set)
 {
 	struct media_request_object *obj;
 	struct v4l2_ctrl_handler *new_hdl;
 	int ret;

 	if (IS_ERR(req))
 		return ERR_CAST(req);

 	if (set && WARN_ON(req->state != MEDIA_REQUEST_STATE_UPDATING))
 		return ERR_PTR(-EBUSY);

 	obj = media_request_object_find(req, &req_ops, hdl);
 	if (obj)
 		return obj;
 	/*
 	 * If there are no controls in this completed request,
 	 * then that can only happen if:
 	 *
 	 * 1) no controls were present in the queued request, and
 	 * 2) v4l2_ctrl_request_complete() could not allocate a
 	 *    control handler object to store the completed state in.
 	 *
 	 * So return ENOMEM to indicate that there was an out-of-memory
 	 * error.
 	 */
 	if (!set)
 		return ERR_PTR(-ENOMEM);

 	new_hdl = kzalloc(sizeof(*new_hdl), GFP_KERNEL);
 	if (!new_hdl)
 		return ERR_PTR(-ENOMEM);

 	obj = &new_hdl->req_obj;
 	ret = v4l2_ctrl_handler_init(new_hdl, (hdl->nr_of_buckets - 1) * 8);
 	if (!ret)
 		ret = v4l2_ctrl_request_bind(req, new_hdl, hdl);
 	if (ret) {
 		v4l2_ctrl_handler_free(new_hdl);
 		kfree(new_hdl);
 		return ERR_PTR(ret);
 	}

 	media_request_object_get(obj);
 	return obj;
 }

 int v4l2_g_ext_ctrls_request(struct v4l2_ctrl_handler *hdl, struct video_device *vdev,
 			     struct media_device *mdev, struct v4l2_ext_controls *cs)
 {
 	struct media_request_object *obj = NULL;
 	struct media_request *req = NULL;
 	int ret;

 	if (!mdev || cs->request_fd < 0)
 		return -EINVAL;

 	req = media_request_get_by_fd(mdev, cs->request_fd);
 	if (IS_ERR(req))
 		return PTR_ERR(req);

 	if (req->state != MEDIA_REQUEST_STATE_COMPLETE) {
 		media_request_put(req);
 		return -EACCES;
 	}

 	ret = media_request_lock_for_access(req);
 	if (ret) {
 		media_request_put(req);
 		return ret;
 	}

 	obj = v4l2_ctrls_find_req_obj(hdl, req, false);
 	if (IS_ERR(obj)) {
 		media_request_unlock_for_access(req);
 		media_request_put(req);
 		return PTR_ERR(obj);
 	}

 	hdl = container_of(obj, struct v4l2_ctrl_handler,
 			   req_obj);
 	ret = v4l2_g_ext_ctrls_common(hdl, cs, vdev);

 	media_request_unlock_for_access(req);
 	media_request_object_put(obj);
 	media_request_put(req);
 	return ret;
 }

 int try_set_ext_ctrls_request(struct v4l2_fh *fh,
 			      struct v4l2_ctrl_handler *hdl,
 			      struct video_device *vdev,
 			      struct media_device *mdev,
 			      struct v4l2_ext_controls *cs, bool set)
 {
 	struct media_request_object *obj = NULL;
 	struct media_request *req = NULL;
 	int ret;

 	if (!mdev) {
 		dprintk(vdev, "%s: missing media device\n",
 			video_device_node_name(vdev));
 		return -EINVAL;
 	}

 	if (cs->request_fd < 0) {
 		dprintk(vdev, "%s: invalid request fd %d\n",
 			video_device_node_name(vdev), cs->request_fd);
 		return -EINVAL;
 	}

 	req = media_request_get_by_fd(mdev, cs->request_fd);
 	if (IS_ERR(req)) {
 		dprintk(vdev, "%s: cannot find request fd %d\n",
 			video_device_node_name(vdev), cs->request_fd);
 		return PTR_ERR(req);
 	}

 	ret = media_request_lock_for_update(req);
 	if (ret) {
 		dprintk(vdev, "%s: cannot lock request fd %d\n",
 			video_device_node_name(vdev), cs->request_fd);
 		media_request_put(req);
 		return ret;
 	}

 	obj = v4l2_ctrls_find_req_obj(hdl, req, set);
 	if (IS_ERR(obj)) {
 		dprintk(vdev,
 			"%s: cannot find request object for request fd %d\n",
 			video_device_node_name(vdev),
 			cs->request_fd);
 		media_request_unlock_for_update(req);
 		media_request_put(req);
 		return PTR_ERR(obj);
 	}

 	hdl = container_of(obj, struct v4l2_ctrl_handler,
 			   req_obj);
 	ret = try_set_ext_ctrls_common(fh, hdl, cs, vdev, set);
 	if (ret)
 		dprintk(vdev,
 			"%s: try_set_ext_ctrls_common failed (%d)\n",
 			video_device_node_name(vdev), ret);

 	media_request_unlock_for_update(req);
 	media_request_object_put(obj);
 	media_request_put(req);

 	return ret;
 }

 void v4l2_ctrl_request_complete(struct media_request *req,
 				struct v4l2_ctrl_handler *main_hdl)
 {
 	struct media_request_object *obj;
 	struct v4l2_ctrl_handler *hdl;
 	struct v4l2_ctrl_ref *ref;

 	if (!req || !main_hdl)
 		return;

 	/*
 	 * Note that it is valid if nothing was found. It means
 	 * that this request doesn't have any controls and so just
 	 * wants to leave the controls unchanged.
 	 */
 	obj = media_request_object_find(req, &req_ops, main_hdl);
 	if (!obj) {
 		int ret;

 		/* Create a new request so the driver can return controls */
 		hdl = kzalloc(sizeof(*hdl), GFP_KERNEL);
 		if (!hdl)
 			return;

 		ret = v4l2_ctrl_handler_init(hdl, (main_hdl->nr_of_buckets - 1) * 8);
 		if (!ret)
 			ret = v4l2_ctrl_request_bind(req, hdl, main_hdl);
 		if (ret) {
 			v4l2_ctrl_handler_free(hdl);
 			kfree(hdl);
 			return;
 		}
 		hdl->request_is_queued = true;
 		obj = media_request_object_find(req, &req_ops, main_hdl);
 	}
 	hdl = container_of(obj, struct v4l2_ctrl_handler, req_obj);

 	list_for_each_entry(ref, &hdl->ctrl_refs, node) {
 		struct v4l2_ctrl *ctrl = ref->ctrl;
 		struct v4l2_ctrl *master = ctrl->cluster[0];
 		unsigned int i;

 		if (ctrl->flags & V4L2_CTRL_FLAG_VOLATILE) {
 			v4l2_ctrl_lock(master);
 			/* g_volatile_ctrl will update the current control values */
 			for (i = 0; i < master->ncontrols; i++)
 				cur_to_new(master->cluster[i]);
 			call_op(master, g_volatile_ctrl);
 			new_to_req(ref);
 			v4l2_ctrl_unlock(master);
 			continue;
 		}
 		if (ref->valid_p_req)
 			continue;

 		/* Copy the current control value into the request */
 		v4l2_ctrl_lock(ctrl);
 		cur_to_req(ref);
 		v4l2_ctrl_unlock(ctrl);
 	}

 	mutex_lock(main_hdl->lock);
 	WARN_ON(!hdl->request_is_queued);
 	list_del_init(&hdl->requests_queued);
 	hdl->request_is_queued = false;
 	mutex_unlock(main_hdl->lock);
 	media_request_object_complete(obj);
 	media_request_object_put(obj);
 }
 EXPORT_SYMBOL(v4l2_ctrl_request_complete);

 int v4l2_ctrl_request_setup(struct media_request *req,
 			    struct v4l2_ctrl_handler *main_hdl)
 {
 	struct media_request_object *obj;
 	struct v4l2_ctrl_handler *hdl;
 	struct v4l2_ctrl_ref *ref;
 	int ret = 0;

 	if (!req || !main_hdl)
 		return 0;

 	if (WARN_ON(req->state != MEDIA_REQUEST_STATE_QUEUED))
 		return -EBUSY;

 	/*
 	 * Note that it is valid if nothing was found. It means
 	 * that this request doesn't have any controls and so just
 	 * wants to leave the controls unchanged.
 	 */
 	obj = media_request_object_find(req, &req_ops, main_hdl);
 	if (!obj)
 		return 0;
 	if (obj->completed) {
 		media_request_object_put(obj);
 		return -EBUSY;
 	}
 	hdl = container_of(obj, struct v4l2_ctrl_handler, req_obj);

 	list_for_each_entry(ref, &hdl->ctrl_refs, node)
 		ref->req_done = false;

 	list_for_each_entry(ref, &hdl->ctrl_refs, node) {
 		struct v4l2_ctrl *ctrl = ref->ctrl;
 		struct v4l2_ctrl *master = ctrl->cluster[0];
 		bool have_new_data = false;
 		int i;

 		/*
 		 * Skip if this control was already handled by a cluster.
 		 * Skip button controls and read-only controls.
 		 */
 		if (ref->req_done || (ctrl->flags & V4L2_CTRL_FLAG_READ_ONLY))
 			continue;

 		v4l2_ctrl_lock(master);
 		for (i = 0; i < master->ncontrols; i++) {
 			if (master->cluster[i]) {
 				struct v4l2_ctrl_ref *r =
 					find_ref(hdl, master->cluster[i]->id);

 				if (r->valid_p_req) {
 					have_new_data = true;
 					break;
 				}
 			}
 		}
 		if (!have_new_data) {
 			v4l2_ctrl_unlock(master);
 			continue;
 		}

 		for (i = 0; i < master->ncontrols; i++) {
 			if (master->cluster[i]) {
 				struct v4l2_ctrl_ref *r =
 					find_ref(hdl, master->cluster[i]->id);

 				req_to_new(r);
 				master->cluster[i]->is_new = 1;
 				r->req_done = true;
 			}
 		}
 		/*
 		 * For volatile autoclusters that are currently in auto mode
 		 * we need to discover if it will be set to manual mode.
 		 * If so, then we have to copy the current volatile values
 		 * first since those will become the new manual values (which
 		 * may be overwritten by explicit new values from this set
 		 * of controls).
 		 */
 		if (master->is_auto && master->has_volatiles &&
 		    !is_cur_manual(master)) {
 			s32 new_auto_val = *master->p_new.p_s32;

 			/*
 			 * If the new value == the manual value, then copy
 			 * the current volatile values.
 			 */
 			if (new_auto_val == master->manual_mode_value)
 				update_from_auto_cluster(master);
 		}

 		ret = try_or_set_cluster(NULL, master, true, 0);
 		v4l2_ctrl_unlock(master);

 		if (ret)
 			break;
 	}

 	media_request_object_put(obj);
 	return ret;
 }
 EXPORT_SYMBOL(v4l2_ctrl_request_setup);
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* V4L2 controls framework Request API implementation.
	*
	* Copyright (C) 2018-2021 Hans Verkuil <hverkuil-cisco@xs4all.nl>
	*/

	#define pr_fmt(fmt) "v4l2-ctrls: " fmt

	#include <linux/export.h>
	#include <linux/slab.h>
	#include <media/v4l2-ctrls.h>
	#include <media/v4l2-dev.h>
	#include <media/v4l2-ioctl.h>

	#include "v4l2-ctrls-priv.h"

	/* Initialize the request-related fields in a control handler */
	void v4l2_ctrl_handler_init_request(struct v4l2_ctrl_handler *hdl)
	{
	INIT_LIST_HEAD(&hdl->requests);
	INIT_LIST_HEAD(&hdl->requests_queued);
	hdl->request_is_queued = false;
	media_request_object_init(&hdl->req_obj);
	}

	/* Free the request-related fields in a control handler */
	void v4l2_ctrl_handler_free_request(struct v4l2_ctrl_handler *hdl)
	{
	struct v4l2_ctrl_handler req, next_req;

	/*
	* Do nothing if this isn't the main handler or the main
	* handler is not used in any request.
	*
	* The main handler can be identified by having a NULL ops pointer in
	* the request object.
	*/
	if (hdl->req_obj.ops \|\| list_empty(&hdl->requests))
	return;

	/*
	* If the main handler is freed and it is used by handler objects in
	* outstanding requests, then unbind and put those objects before
	* freeing the main handler.
	*/
	list_for_each_entry_safe(req, next_req, &hdl->requests, requests) {
	media_request_object_unbind(&req->req_obj);
	media_request_object_put(&req->req_obj);
	}
	}

	static int v4l2_ctrl_request_clone(struct v4l2_ctrl_handler *hdl,
	const struct v4l2_ctrl_handler *from)
	{
	struct v4l2_ctrl_ref *ref;
	int err = 0;

	if (WARN_ON(!hdl \|\| hdl == from))
	return -EINVAL;

	if (hdl->error)
	return hdl->error;

	WARN_ON(hdl->lock != &hdl->_lock);

	mutex_lock(from->lock);
	list_for_each_entry(ref, &from->ctrl_refs, node) {
	struct v4l2_ctrl *ctrl = ref->ctrl;
	struct v4l2_ctrl_ref *new_ref;

	/* Skip refs inherited from other devices */
	if (ref->from_other_dev)
	continue;
	err = handler_new_ref(hdl, ctrl, &new_ref, false, true);
	if (err)
	break;
	}
	mutex_unlock(from->lock);
	return err;
	}

	static void v4l2_ctrl_request_queue(struct media_request_object *obj)
	{
	struct v4l2_ctrl_handler *hdl =
	container_of(obj, struct v4l2_ctrl_handler, req_obj);
	struct v4l2_ctrl_handler *main_hdl = obj->priv;

	mutex_lock(main_hdl->lock);
	list_add_tail(&hdl->requests_queued, &main_hdl->requests_queued);
	hdl->request_is_queued = true;
	mutex_unlock(main_hdl->lock);
	}

	static void v4l2_ctrl_request_unbind(struct media_request_object *obj)
	{
	struct v4l2_ctrl_handler *hdl =
	container_of(obj, struct v4l2_ctrl_handler, req_obj);
	struct v4l2_ctrl_handler *main_hdl = obj->priv;

	mutex_lock(main_hdl->lock);
	list_del_init(&hdl->requests);
	if (hdl->request_is_queued) {
	list_del_init(&hdl->requests_queued);
	hdl->request_is_queued = false;
	}
	mutex_unlock(main_hdl->lock);
	}

	static void v4l2_ctrl_request_release(struct media_request_object *obj)
	{
	struct v4l2_ctrl_handler *hdl =
	container_of(obj, struct v4l2_ctrl_handler, req_obj);

	v4l2_ctrl_handler_free(hdl);
	kfree(hdl);
	}

	static const struct media_request_object_ops req_ops = {
	.queue = v4l2_ctrl_request_queue,
	.unbind = v4l2_ctrl_request_unbind,
	.release = v4l2_ctrl_request_release,
	};

	struct v4l2_ctrl_handler v4l2_ctrl_request_hdl_find(struct media_request req,
	struct v4l2_ctrl_handler *parent)
	{
	struct media_request_object *obj;

	if (WARN_ON(req->state != MEDIA_REQUEST_STATE_VALIDATING &&
	req->state != MEDIA_REQUEST_STATE_QUEUED))
	return NULL;

	obj = media_request_object_find(req, &req_ops, parent);
	if (obj)
	return container_of(obj, struct v4l2_ctrl_handler, req_obj);
	return NULL;
	}
	EXPORT_SYMBOL_GPL(v4l2_ctrl_request_hdl_find);

	struct v4l2_ctrl *
	v4l2_ctrl_request_hdl_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id)
	{
	struct v4l2_ctrl_ref *ref = find_ref_lock(hdl, id);

	return (ref && ref->valid_p_req) ? ref->ctrl : NULL;
	}
	EXPORT_SYMBOL_GPL(v4l2_ctrl_request_hdl_ctrl_find);

	static int v4l2_ctrl_request_bind(struct media_request *req,
	struct v4l2_ctrl_handler *hdl,
	struct v4l2_ctrl_handler *from)
	{
	int ret;

	ret = v4l2_ctrl_request_clone(hdl, from);

	if (!ret) {
	ret = media_request_object_bind(req, &req_ops,
	from, false, &hdl->req_obj);
	if (!ret) {
	mutex_lock(from->lock);
	list_add_tail(&hdl->requests, &from->requests);
	mutex_unlock(from->lock);
	}
	}
	return ret;
	}

	static struct media_request_object *
	v4l2_ctrls_find_req_obj(struct v4l2_ctrl_handler *hdl,
	struct media_request *req, bool set)
	{
	struct media_request_object *obj;
	struct v4l2_ctrl_handler *new_hdl;
	int ret;

	if (IS_ERR(req))
	return ERR_CAST(req);

	if (set && WARN_ON(req->state != MEDIA_REQUEST_STATE_UPDATING))
	return ERR_PTR(-EBUSY);

	obj = media_request_object_find(req, &req_ops, hdl);
	if (obj)
	return obj;
	/*
	* If there are no controls in this completed request,
	* then that can only happen if:
	*
	* 1) no controls were present in the queued request, and
	* 2) v4l2_ctrl_request_complete() could not allocate a
	* control handler object to store the completed state in.
	*
	* So return ENOMEM to indicate that there was an out-of-memory
	* error.
	*/
	if (!set)
	return ERR_PTR(-ENOMEM);

	new_hdl = kzalloc(sizeof(*new_hdl), GFP_KERNEL);
	if (!new_hdl)
	return ERR_PTR(-ENOMEM);

	obj = &new_hdl->req_obj;
	ret = v4l2_ctrl_handler_init(new_hdl, (hdl->nr_of_buckets - 1) * 8);
	if (!ret)
	ret = v4l2_ctrl_request_bind(req, new_hdl, hdl);
	if (ret) {
	v4l2_ctrl_handler_free(new_hdl);
	kfree(new_hdl);
	return ERR_PTR(ret);
	}

	media_request_object_get(obj);
	return obj;
	}

	int v4l2_g_ext_ctrls_request(struct v4l2_ctrl_handler hdl, struct video_device vdev,
	struct media_device mdev, struct v4l2_ext_controls cs)
	{
	struct media_request_object *obj = NULL;
	struct media_request *req = NULL;
	int ret;

	if (!mdev \|\| cs->request_fd < 0)
	return -EINVAL;

	req = media_request_get_by_fd(mdev, cs->request_fd);
	if (IS_ERR(req))
	return PTR_ERR(req);

	if (req->state != MEDIA_REQUEST_STATE_COMPLETE) {
	media_request_put(req);
	return -EACCES;
	}

	ret = media_request_lock_for_access(req);
	if (ret) {
	media_request_put(req);
	return ret;
	}

	obj = v4l2_ctrls_find_req_obj(hdl, req, false);
	if (IS_ERR(obj)) {
	media_request_unlock_for_access(req);
	media_request_put(req);
	return PTR_ERR(obj);
	}

	hdl = container_of(obj, struct v4l2_ctrl_handler,
	req_obj);
	ret = v4l2_g_ext_ctrls_common(hdl, cs, vdev);

	media_request_unlock_for_access(req);
	media_request_object_put(obj);
	media_request_put(req);
	return ret;
	}

	int try_set_ext_ctrls_request(struct v4l2_fh *fh,
	struct v4l2_ctrl_handler *hdl,
	struct video_device *vdev,
	struct media_device *mdev,
	struct v4l2_ext_controls *cs, bool set)
	{
	struct media_request_object *obj = NULL;
	struct media_request *req = NULL;
	int ret;

	if (!mdev) {
	dprintk(vdev, "%s: missing media device\n",
	video_device_node_name(vdev));
	return -EINVAL;
	}

	if (cs->request_fd < 0) {
	dprintk(vdev, "%s: invalid request fd %d\n",
	video_device_node_name(vdev), cs->request_fd);
	return -EINVAL;
	}

	req = media_request_get_by_fd(mdev, cs->request_fd);
	if (IS_ERR(req)) {
	dprintk(vdev, "%s: cannot find request fd %d\n",
	video_device_node_name(vdev), cs->request_fd);
	return PTR_ERR(req);
	}

	ret = media_request_lock_for_update(req);
	if (ret) {
	dprintk(vdev, "%s: cannot lock request fd %d\n",
	video_device_node_name(vdev), cs->request_fd);
	media_request_put(req);
	return ret;
	}

	obj = v4l2_ctrls_find_req_obj(hdl, req, set);
	if (IS_ERR(obj)) {
	dprintk(vdev,
	"%s: cannot find request object for request fd %d\n",
	video_device_node_name(vdev),
	cs->request_fd);
	media_request_unlock_for_update(req);
	media_request_put(req);
	return PTR_ERR(obj);
	}

	hdl = container_of(obj, struct v4l2_ctrl_handler,
	req_obj);
	ret = try_set_ext_ctrls_common(fh, hdl, cs, vdev, set);
	if (ret)
	dprintk(vdev,
	"%s: try_set_ext_ctrls_common failed (%d)\n",
	video_device_node_name(vdev), ret);

	media_request_unlock_for_update(req);
	media_request_object_put(obj);
	media_request_put(req);

	return ret;
	}

	void v4l2_ctrl_request_complete(struct media_request *req,
	struct v4l2_ctrl_handler *main_hdl)
	{
	struct media_request_object *obj;
	struct v4l2_ctrl_handler *hdl;
	struct v4l2_ctrl_ref *ref;

	if (!req \|\| !main_hdl)
	return;

	/*
	* Note that it is valid if nothing was found. It means
	* that this request doesn't have any controls and so just
	* wants to leave the controls unchanged.
	*/
	obj = media_request_object_find(req, &req_ops, main_hdl);
	if (!obj) {
	int ret;

	/* Create a new request so the driver can return controls */
	hdl = kzalloc(sizeof(*hdl), GFP_KERNEL);
	if (!hdl)
	return;

	ret = v4l2_ctrl_handler_init(hdl, (main_hdl->nr_of_buckets - 1) * 8);
	if (!ret)
	ret = v4l2_ctrl_request_bind(req, hdl, main_hdl);
	if (ret) {
	v4l2_ctrl_handler_free(hdl);
	kfree(hdl);
	return;
	}
	hdl->request_is_queued = true;
	obj = media_request_object_find(req, &req_ops, main_hdl);
	}
	hdl = container_of(obj, struct v4l2_ctrl_handler, req_obj);

	list_for_each_entry(ref, &hdl->ctrl_refs, node) {
	struct v4l2_ctrl *ctrl = ref->ctrl;
	struct v4l2_ctrl *master = ctrl->cluster[0];
	unsigned int i;

	if (ctrl->flags & V4L2_CTRL_FLAG_VOLATILE) {
	v4l2_ctrl_lock(master);
	/* g_volatile_ctrl will update the current control values */
	for (i = 0; i < master->ncontrols; i++)
	cur_to_new(master->cluster[i]);
	call_op(master, g_volatile_ctrl);
	new_to_req(ref);
	v4l2_ctrl_unlock(master);
	continue;
	}
	if (ref->valid_p_req)
	continue;

	/* Copy the current control value into the request */
	v4l2_ctrl_lock(ctrl);
	cur_to_req(ref);
	v4l2_ctrl_unlock(ctrl);
	}

	mutex_lock(main_hdl->lock);
	WARN_ON(!hdl->request_is_queued);
	list_del_init(&hdl->requests_queued);
	hdl->request_is_queued = false;
	mutex_unlock(main_hdl->lock);
	media_request_object_complete(obj);
	media_request_object_put(obj);
	}
	EXPORT_SYMBOL(v4l2_ctrl_request_complete);

	int v4l2_ctrl_request_setup(struct media_request *req,
	struct v4l2_ctrl_handler *main_hdl)
	{
	struct media_request_object *obj;
	struct v4l2_ctrl_handler *hdl;
	struct v4l2_ctrl_ref *ref;
	int ret = 0;

	if (!req \|\| !main_hdl)
	return 0;

	if (WARN_ON(req->state != MEDIA_REQUEST_STATE_QUEUED))
	return -EBUSY;

	/*
	* Note that it is valid if nothing was found. It means
	* that this request doesn't have any controls and so just
	* wants to leave the controls unchanged.
	*/
	obj = media_request_object_find(req, &req_ops, main_hdl);
	if (!obj)
	return 0;
	if (obj->completed) {
	media_request_object_put(obj);
	return -EBUSY;
	}
	hdl = container_of(obj, struct v4l2_ctrl_handler, req_obj);

	list_for_each_entry(ref, &hdl->ctrl_refs, node)
	ref->req_done = false;

	list_for_each_entry(ref, &hdl->ctrl_refs, node) {
	struct v4l2_ctrl *ctrl = ref->ctrl;
	struct v4l2_ctrl *master = ctrl->cluster[0];
	bool have_new_data = false;
	int i;

	/*
	* Skip if this control was already handled by a cluster.
	* Skip button controls and read-only controls.
	*/
	if (ref->req_done \|\| (ctrl->flags & V4L2_CTRL_FLAG_READ_ONLY))
	continue;

	v4l2_ctrl_lock(master);
	for (i = 0; i < master->ncontrols; i++) {
	if (master->cluster[i]) {
	struct v4l2_ctrl_ref *r =
	find_ref(hdl, master->cluster[i]->id);

	if (r->valid_p_req) {
	have_new_data = true;
	break;
	}
	}
	}
	if (!have_new_data) {
	v4l2_ctrl_unlock(master);
	continue;
	}

	for (i = 0; i < master->ncontrols; i++) {
	if (master->cluster[i]) {
	struct v4l2_ctrl_ref *r =
	find_ref(hdl, master->cluster[i]->id);

	req_to_new(r);
	master->cluster[i]->is_new = 1;
	r->req_done = true;
	}
	}
	/*
	* For volatile autoclusters that are currently in auto mode
	* we need to discover if it will be set to manual mode.
	* If so, then we have to copy the current volatile values
	* first since those will become the new manual values (which
	* may be overwritten by explicit new values from this set
	* of controls).
	*/
	if (master->is_auto && master->has_volatiles &&
	!is_cur_manual(master)) {
	s32 new_auto_val = *master->p_new.p_s32;

	/*
	* If the new value == the manual value, then copy
	* the current volatile values.
	*/
	if (new_auto_val == master->manual_mode_value)
	update_from_auto_cluster(master);
	}

	ret = try_or_set_cluster(NULL, master, true, 0);
	v4l2_ctrl_unlock(master);

	if (ret)
	break;
	}

	media_request_object_put(obj);
	return ret;
	}
	EXPORT_SYMBOL(v4l2_ctrl_request_setup);