![Mauro Carvalho Chehab](/assets/img/avatar_default.png)
The V4L2_ASYNC_MATCH_FWNODE match criteria requires just one struct to be filled (struct fwnode_handle). The V4L2_ASYNC_MATCH_DEVNAME match criteria requires just a device name. So, it doesn't make sense to enclose those into structs, as the criteria can go directly into the union. That makes easier to document it, as we don't need to document weird senseless structs. At drivers, this makes even clearer about the match criteria. Acked-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Acked-by: Benoit Parrot <bparrot@ti.com> Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> Acked-by: Philipp Zabel <p.zabel@pengutronix.de> Acked-by: Hyun Kwon <hyun.kwon@xilinx.com> Acked-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se> Acked-by: Lad, Prabhakar <prabhakar.csengg@gmail.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
621 lines
14 KiB
C
621 lines
14 KiB
C
/*
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* V4L2 asynchronous subdevice registration API
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*
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* Copyright (C) 2012-2013, Guennadi Liakhovetski <g.liakhovetski@gmx.de>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/device.h>
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#include <linux/err.h>
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#include <linux/i2c.h>
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#include <linux/list.h>
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#include <linux/mm.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#include <linux/types.h>
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#include <media/v4l2-async.h>
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#include <media/v4l2-device.h>
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#include <media/v4l2-fwnode.h>
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#include <media/v4l2-subdev.h>
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static int v4l2_async_notifier_call_bound(struct v4l2_async_notifier *n,
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struct v4l2_subdev *subdev,
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struct v4l2_async_subdev *asd)
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{
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if (!n->ops || !n->ops->bound)
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return 0;
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return n->ops->bound(n, subdev, asd);
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}
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static void v4l2_async_notifier_call_unbind(struct v4l2_async_notifier *n,
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struct v4l2_subdev *subdev,
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struct v4l2_async_subdev *asd)
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{
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if (!n->ops || !n->ops->unbind)
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return;
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n->ops->unbind(n, subdev, asd);
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}
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static int v4l2_async_notifier_call_complete(struct v4l2_async_notifier *n)
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{
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if (!n->ops || !n->ops->complete)
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return 0;
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return n->ops->complete(n);
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}
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static bool match_i2c(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
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{
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#if IS_ENABLED(CONFIG_I2C)
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struct i2c_client *client = i2c_verify_client(sd->dev);
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return client &&
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asd->match.i2c.adapter_id == client->adapter->nr &&
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asd->match.i2c.address == client->addr;
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#else
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return false;
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#endif
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}
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static bool match_devname(struct v4l2_subdev *sd,
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struct v4l2_async_subdev *asd)
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{
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return !strcmp(asd->match.device_name, dev_name(sd->dev));
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}
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static bool match_fwnode(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
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{
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return sd->fwnode == asd->match.fwnode;
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}
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static bool match_custom(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
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{
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if (!asd->match.custom.match)
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/* Match always */
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return true;
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return asd->match.custom.match(sd->dev, asd);
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}
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static LIST_HEAD(subdev_list);
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static LIST_HEAD(notifier_list);
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static DEFINE_MUTEX(list_lock);
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static struct v4l2_async_subdev *v4l2_async_find_match(
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struct v4l2_async_notifier *notifier, struct v4l2_subdev *sd)
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{
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bool (*match)(struct v4l2_subdev *, struct v4l2_async_subdev *);
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struct v4l2_async_subdev *asd;
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list_for_each_entry(asd, ¬ifier->waiting, list) {
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/* bus_type has been verified valid before */
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switch (asd->match_type) {
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case V4L2_ASYNC_MATCH_CUSTOM:
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match = match_custom;
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break;
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case V4L2_ASYNC_MATCH_DEVNAME:
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match = match_devname;
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break;
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case V4L2_ASYNC_MATCH_I2C:
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match = match_i2c;
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break;
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case V4L2_ASYNC_MATCH_FWNODE:
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match = match_fwnode;
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break;
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default:
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/* Cannot happen, unless someone breaks us */
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WARN_ON(true);
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return NULL;
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}
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/* match cannot be NULL here */
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if (match(sd, asd))
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return asd;
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}
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return NULL;
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}
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/* Find the sub-device notifier registered by a sub-device driver. */
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static struct v4l2_async_notifier *v4l2_async_find_subdev_notifier(
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struct v4l2_subdev *sd)
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{
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struct v4l2_async_notifier *n;
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list_for_each_entry(n, ¬ifier_list, list)
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if (n->sd == sd)
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return n;
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return NULL;
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}
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/* Get v4l2_device related to the notifier if one can be found. */
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static struct v4l2_device *v4l2_async_notifier_find_v4l2_dev(
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struct v4l2_async_notifier *notifier)
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{
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while (notifier->parent)
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notifier = notifier->parent;
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return notifier->v4l2_dev;
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}
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/*
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* Return true if all child sub-device notifiers are complete, false otherwise.
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*/
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static bool v4l2_async_notifier_can_complete(
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struct v4l2_async_notifier *notifier)
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{
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struct v4l2_subdev *sd;
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if (!list_empty(¬ifier->waiting))
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return false;
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list_for_each_entry(sd, ¬ifier->done, async_list) {
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struct v4l2_async_notifier *subdev_notifier =
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v4l2_async_find_subdev_notifier(sd);
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if (subdev_notifier &&
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!v4l2_async_notifier_can_complete(subdev_notifier))
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return false;
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}
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return true;
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}
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/*
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* Complete the master notifier if possible. This is done when all async
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* sub-devices have been bound; v4l2_device is also available then.
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*/
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static int v4l2_async_notifier_try_complete(
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struct v4l2_async_notifier *notifier)
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{
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/* Quick check whether there are still more sub-devices here. */
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if (!list_empty(¬ifier->waiting))
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return 0;
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/* Check the entire notifier tree; find the root notifier first. */
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while (notifier->parent)
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notifier = notifier->parent;
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/* This is root if it has v4l2_dev. */
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if (!notifier->v4l2_dev)
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return 0;
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/* Is everything ready? */
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if (!v4l2_async_notifier_can_complete(notifier))
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return 0;
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return v4l2_async_notifier_call_complete(notifier);
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}
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static int v4l2_async_notifier_try_all_subdevs(
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struct v4l2_async_notifier *notifier);
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static int v4l2_async_match_notify(struct v4l2_async_notifier *notifier,
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struct v4l2_device *v4l2_dev,
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struct v4l2_subdev *sd,
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struct v4l2_async_subdev *asd)
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{
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struct v4l2_async_notifier *subdev_notifier;
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int ret;
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ret = v4l2_device_register_subdev(v4l2_dev, sd);
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if (ret < 0)
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return ret;
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ret = v4l2_async_notifier_call_bound(notifier, sd, asd);
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if (ret < 0) {
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v4l2_device_unregister_subdev(sd);
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return ret;
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}
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/* Remove from the waiting list */
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list_del(&asd->list);
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sd->asd = asd;
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sd->notifier = notifier;
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/* Move from the global subdevice list to notifier's done */
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list_move(&sd->async_list, ¬ifier->done);
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/*
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* See if the sub-device has a notifier. If not, return here.
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*/
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subdev_notifier = v4l2_async_find_subdev_notifier(sd);
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if (!subdev_notifier || subdev_notifier->parent)
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return 0;
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/*
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* Proceed with checking for the sub-device notifier's async
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* sub-devices, and return the result. The error will be handled by the
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* caller.
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*/
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subdev_notifier->parent = notifier;
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return v4l2_async_notifier_try_all_subdevs(subdev_notifier);
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}
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/* Test all async sub-devices in a notifier for a match. */
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static int v4l2_async_notifier_try_all_subdevs(
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struct v4l2_async_notifier *notifier)
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{
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struct v4l2_device *v4l2_dev =
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v4l2_async_notifier_find_v4l2_dev(notifier);
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struct v4l2_subdev *sd;
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if (!v4l2_dev)
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return 0;
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again:
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list_for_each_entry(sd, &subdev_list, async_list) {
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struct v4l2_async_subdev *asd;
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int ret;
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asd = v4l2_async_find_match(notifier, sd);
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if (!asd)
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continue;
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ret = v4l2_async_match_notify(notifier, v4l2_dev, sd, asd);
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if (ret < 0)
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return ret;
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/*
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* v4l2_async_match_notify() may lead to registering a
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* new notifier and thus changing the async subdevs
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* list. In order to proceed safely from here, restart
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* parsing the list from the beginning.
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*/
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goto again;
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}
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return 0;
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}
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static void v4l2_async_cleanup(struct v4l2_subdev *sd)
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{
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v4l2_device_unregister_subdev(sd);
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/* Subdevice driver will reprobe and put the subdev back onto the list */
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list_del_init(&sd->async_list);
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sd->asd = NULL;
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}
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/* Unbind all sub-devices in the notifier tree. */
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static void v4l2_async_notifier_unbind_all_subdevs(
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struct v4l2_async_notifier *notifier)
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{
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struct v4l2_subdev *sd, *tmp;
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list_for_each_entry_safe(sd, tmp, ¬ifier->done, async_list) {
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struct v4l2_async_notifier *subdev_notifier =
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v4l2_async_find_subdev_notifier(sd);
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if (subdev_notifier)
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v4l2_async_notifier_unbind_all_subdevs(subdev_notifier);
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v4l2_async_notifier_call_unbind(notifier, sd, sd->asd);
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v4l2_async_cleanup(sd);
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list_move(&sd->async_list, &subdev_list);
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}
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notifier->parent = NULL;
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}
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/* See if an fwnode can be found in a notifier's lists. */
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static bool __v4l2_async_notifier_fwnode_has_async_subdev(
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struct v4l2_async_notifier *notifier, struct fwnode_handle *fwnode)
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{
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struct v4l2_async_subdev *asd;
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struct v4l2_subdev *sd;
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list_for_each_entry(asd, ¬ifier->waiting, list) {
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if (asd->match_type != V4L2_ASYNC_MATCH_FWNODE)
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continue;
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if (asd->match.fwnode == fwnode)
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return true;
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}
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list_for_each_entry(sd, ¬ifier->done, async_list) {
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if (WARN_ON(!sd->asd))
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continue;
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if (sd->asd->match_type != V4L2_ASYNC_MATCH_FWNODE)
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continue;
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if (sd->asd->match.fwnode == fwnode)
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return true;
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}
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return false;
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}
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/*
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* Find out whether an async sub-device was set up for an fwnode already or
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* whether it exists in a given notifier before @this_index.
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*/
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static bool v4l2_async_notifier_fwnode_has_async_subdev(
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struct v4l2_async_notifier *notifier, struct fwnode_handle *fwnode,
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unsigned int this_index)
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{
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unsigned int j;
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lockdep_assert_held(&list_lock);
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/* Check that an fwnode is not being added more than once. */
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for (j = 0; j < this_index; j++) {
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struct v4l2_async_subdev *asd = notifier->subdevs[this_index];
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struct v4l2_async_subdev *other_asd = notifier->subdevs[j];
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if (other_asd->match_type == V4L2_ASYNC_MATCH_FWNODE &&
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asd->match.fwnode ==
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other_asd->match.fwnode)
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return true;
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}
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/* Check than an fwnode did not exist in other notifiers. */
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list_for_each_entry(notifier, ¬ifier_list, list)
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if (__v4l2_async_notifier_fwnode_has_async_subdev(
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notifier, fwnode))
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return true;
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return false;
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}
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static int __v4l2_async_notifier_register(struct v4l2_async_notifier *notifier)
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{
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struct device *dev =
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notifier->v4l2_dev ? notifier->v4l2_dev->dev : NULL;
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struct v4l2_async_subdev *asd;
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int ret;
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int i;
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if (notifier->num_subdevs > V4L2_MAX_SUBDEVS)
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return -EINVAL;
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INIT_LIST_HEAD(¬ifier->waiting);
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INIT_LIST_HEAD(¬ifier->done);
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mutex_lock(&list_lock);
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for (i = 0; i < notifier->num_subdevs; i++) {
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asd = notifier->subdevs[i];
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switch (asd->match_type) {
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case V4L2_ASYNC_MATCH_CUSTOM:
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case V4L2_ASYNC_MATCH_DEVNAME:
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case V4L2_ASYNC_MATCH_I2C:
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break;
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case V4L2_ASYNC_MATCH_FWNODE:
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if (v4l2_async_notifier_fwnode_has_async_subdev(
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notifier, asd->match.fwnode, i)) {
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dev_err(dev,
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"fwnode has already been registered or in notifier's subdev list\n");
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ret = -EEXIST;
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goto err_unlock;
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}
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break;
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default:
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dev_err(dev, "Invalid match type %u on %p\n",
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asd->match_type, asd);
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ret = -EINVAL;
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goto err_unlock;
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}
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list_add_tail(&asd->list, ¬ifier->waiting);
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}
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ret = v4l2_async_notifier_try_all_subdevs(notifier);
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if (ret < 0)
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goto err_unbind;
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ret = v4l2_async_notifier_try_complete(notifier);
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if (ret < 0)
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goto err_unbind;
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/* Keep also completed notifiers on the list */
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list_add(¬ifier->list, ¬ifier_list);
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mutex_unlock(&list_lock);
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return 0;
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err_unbind:
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/*
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* On failure, unbind all sub-devices registered through this notifier.
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*/
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v4l2_async_notifier_unbind_all_subdevs(notifier);
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err_unlock:
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mutex_unlock(&list_lock);
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return ret;
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}
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int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
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struct v4l2_async_notifier *notifier)
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{
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int ret;
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if (WARN_ON(!v4l2_dev || notifier->sd))
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return -EINVAL;
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notifier->v4l2_dev = v4l2_dev;
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ret = __v4l2_async_notifier_register(notifier);
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if (ret)
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notifier->v4l2_dev = NULL;
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return ret;
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}
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EXPORT_SYMBOL(v4l2_async_notifier_register);
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int v4l2_async_subdev_notifier_register(struct v4l2_subdev *sd,
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struct v4l2_async_notifier *notifier)
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{
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int ret;
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if (WARN_ON(!sd || notifier->v4l2_dev))
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return -EINVAL;
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notifier->sd = sd;
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ret = __v4l2_async_notifier_register(notifier);
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if (ret)
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notifier->sd = NULL;
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return ret;
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}
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EXPORT_SYMBOL(v4l2_async_subdev_notifier_register);
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static void __v4l2_async_notifier_unregister(
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struct v4l2_async_notifier *notifier)
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{
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if (!notifier || (!notifier->v4l2_dev && !notifier->sd))
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return;
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v4l2_async_notifier_unbind_all_subdevs(notifier);
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notifier->sd = NULL;
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notifier->v4l2_dev = NULL;
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list_del(¬ifier->list);
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}
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void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
|
|
{
|
|
mutex_lock(&list_lock);
|
|
|
|
__v4l2_async_notifier_unregister(notifier);
|
|
|
|
mutex_unlock(&list_lock);
|
|
}
|
|
EXPORT_SYMBOL(v4l2_async_notifier_unregister);
|
|
|
|
void v4l2_async_notifier_cleanup(struct v4l2_async_notifier *notifier)
|
|
{
|
|
unsigned int i;
|
|
|
|
if (!notifier || !notifier->max_subdevs)
|
|
return;
|
|
|
|
for (i = 0; i < notifier->num_subdevs; i++) {
|
|
struct v4l2_async_subdev *asd = notifier->subdevs[i];
|
|
|
|
switch (asd->match_type) {
|
|
case V4L2_ASYNC_MATCH_FWNODE:
|
|
fwnode_handle_put(asd->match.fwnode);
|
|
break;
|
|
default:
|
|
WARN_ON_ONCE(true);
|
|
break;
|
|
}
|
|
|
|
kfree(asd);
|
|
}
|
|
|
|
notifier->max_subdevs = 0;
|
|
notifier->num_subdevs = 0;
|
|
|
|
kvfree(notifier->subdevs);
|
|
notifier->subdevs = NULL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(v4l2_async_notifier_cleanup);
|
|
|
|
int v4l2_async_register_subdev(struct v4l2_subdev *sd)
|
|
{
|
|
struct v4l2_async_notifier *subdev_notifier;
|
|
struct v4l2_async_notifier *notifier;
|
|
int ret;
|
|
|
|
/*
|
|
* No reference taken. The reference is held by the device
|
|
* (struct v4l2_subdev.dev), and async sub-device does not
|
|
* exist independently of the device at any point of time.
|
|
*/
|
|
if (!sd->fwnode && sd->dev)
|
|
sd->fwnode = dev_fwnode(sd->dev);
|
|
|
|
mutex_lock(&list_lock);
|
|
|
|
INIT_LIST_HEAD(&sd->async_list);
|
|
|
|
list_for_each_entry(notifier, ¬ifier_list, list) {
|
|
struct v4l2_device *v4l2_dev =
|
|
v4l2_async_notifier_find_v4l2_dev(notifier);
|
|
struct v4l2_async_subdev *asd;
|
|
|
|
if (!v4l2_dev)
|
|
continue;
|
|
|
|
asd = v4l2_async_find_match(notifier, sd);
|
|
if (!asd)
|
|
continue;
|
|
|
|
ret = v4l2_async_match_notify(notifier, v4l2_dev, sd, asd);
|
|
if (ret)
|
|
goto err_unbind;
|
|
|
|
ret = v4l2_async_notifier_try_complete(notifier);
|
|
if (ret)
|
|
goto err_unbind;
|
|
|
|
goto out_unlock;
|
|
}
|
|
|
|
/* None matched, wait for hot-plugging */
|
|
list_add(&sd->async_list, &subdev_list);
|
|
|
|
out_unlock:
|
|
mutex_unlock(&list_lock);
|
|
|
|
return 0;
|
|
|
|
err_unbind:
|
|
/*
|
|
* Complete failed. Unbind the sub-devices bound through registering
|
|
* this async sub-device.
|
|
*/
|
|
subdev_notifier = v4l2_async_find_subdev_notifier(sd);
|
|
if (subdev_notifier)
|
|
v4l2_async_notifier_unbind_all_subdevs(subdev_notifier);
|
|
|
|
if (sd->asd)
|
|
v4l2_async_notifier_call_unbind(notifier, sd, sd->asd);
|
|
v4l2_async_cleanup(sd);
|
|
|
|
mutex_unlock(&list_lock);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(v4l2_async_register_subdev);
|
|
|
|
void v4l2_async_unregister_subdev(struct v4l2_subdev *sd)
|
|
{
|
|
mutex_lock(&list_lock);
|
|
|
|
__v4l2_async_notifier_unregister(sd->subdev_notifier);
|
|
v4l2_async_notifier_cleanup(sd->subdev_notifier);
|
|
kfree(sd->subdev_notifier);
|
|
sd->subdev_notifier = NULL;
|
|
|
|
if (sd->asd) {
|
|
struct v4l2_async_notifier *notifier = sd->notifier;
|
|
|
|
list_add(&sd->asd->list, ¬ifier->waiting);
|
|
|
|
v4l2_async_notifier_call_unbind(notifier, sd, sd->asd);
|
|
}
|
|
|
|
v4l2_async_cleanup(sd);
|
|
|
|
mutex_unlock(&list_lock);
|
|
}
|
|
EXPORT_SYMBOL(v4l2_async_unregister_subdev);
|