Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 620 insertions, 0 deletions

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
new file mode 100644
index 000000000..2b08d03b2
--- /dev/null
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -0,0 +1,620 @@
+/*
+ * V4L2 asynchronous subdevice registration API
+ *
+ * Copyright (C) 2012-2013, Guennadi Liakhovetski <g.liakhovetski@gmx.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/list.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include <media/v4l2-async.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-fwnode.h>
+#include <media/v4l2-subdev.h>
+
+static int v4l2_async_notifier_call_bound(struct v4l2_async_notifier *n,
+					  struct v4l2_subdev *subdev,
+					  struct v4l2_async_subdev *asd)
+{
+	if (!n->ops || !n->ops->bound)
+		return 0;
+
+	return n->ops->bound(n, subdev, asd);
+}
+
+static void v4l2_async_notifier_call_unbind(struct v4l2_async_notifier *n,
+					    struct v4l2_subdev *subdev,
+					    struct v4l2_async_subdev *asd)
+{
+	if (!n->ops || !n->ops->unbind)
+		return;
+
+	n->ops->unbind(n, subdev, asd);
+}
+
+static int v4l2_async_notifier_call_complete(struct v4l2_async_notifier *n)
+{
+	if (!n->ops || !n->ops->complete)
+		return 0;
+
+	return n->ops->complete(n);
+}
+
+static bool match_i2c(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
+{
+#if IS_ENABLED(CONFIG_I2C)
+	struct i2c_client *client = i2c_verify_client(sd->dev);
+	return client &&
+		asd->match.i2c.adapter_id == client->adapter->nr &&
+		asd->match.i2c.address == client->addr;
+#else
+	return false;
+#endif
+}
+
+static bool match_devname(struct v4l2_subdev *sd,
+			  struct v4l2_async_subdev *asd)
+{
+	return !strcmp(asd->match.device_name, dev_name(sd->dev));
+}
+
+static bool match_fwnode(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
+{
+	return sd->fwnode == asd->match.fwnode;
+}
+
+static bool match_custom(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
+{
+	if (!asd->match.custom.match)
+		/* Match always */
+		return true;
+
+	return asd->match.custom.match(sd->dev, asd);
+}
+
+static LIST_HEAD(subdev_list);
+static LIST_HEAD(notifier_list);
+static DEFINE_MUTEX(list_lock);
+
+static struct v4l2_async_subdev *v4l2_async_find_match(
+	struct v4l2_async_notifier *notifier, struct v4l2_subdev *sd)
+{
+	bool (*match)(struct v4l2_subdev *, struct v4l2_async_subdev *);
+	struct v4l2_async_subdev *asd;
+
+	list_for_each_entry(asd, &notifier->waiting, list) {
+		/* bus_type has been verified valid before */
+		switch (asd->match_type) {
+		case V4L2_ASYNC_MATCH_CUSTOM:
+			match = match_custom;
+			break;
+		case V4L2_ASYNC_MATCH_DEVNAME:
+			match = match_devname;
+			break;
+		case V4L2_ASYNC_MATCH_I2C:
+			match = match_i2c;
+			break;
+		case V4L2_ASYNC_MATCH_FWNODE:
+			match = match_fwnode;
+			break;
+		default:
+			/* Cannot happen, unless someone breaks us */
+			WARN_ON(true);
+			return NULL;
+		}
+
+		/* match cannot be NULL here */
+		if (match(sd, asd))
+			return asd;
+	}
+
+	return NULL;
+}
+
+/* Find the sub-device notifier registered by a sub-device driver. */
+static struct v4l2_async_notifier *v4l2_async_find_subdev_notifier(
+	struct v4l2_subdev *sd)
+{
+	struct v4l2_async_notifier *n;
+
+	list_for_each_entry(n, &notifier_list, list)
+		if (n->sd == sd)
+			return n;
+
+	return NULL;
+}
+
+/* Get v4l2_device related to the notifier if one can be found. */
+static struct v4l2_device *v4l2_async_notifier_find_v4l2_dev(
+	struct v4l2_async_notifier *notifier)
+{
+	while (notifier->parent)
+		notifier = notifier->parent;
+
+	return notifier->v4l2_dev;
+}
+
+/*
+ * Return true if all child sub-device notifiers are complete, false otherwise.
+ */
+static bool v4l2_async_notifier_can_complete(
+	struct v4l2_async_notifier *notifier)
+{
+	struct v4l2_subdev *sd;
+
+	if (!list_empty(&notifier->waiting))
+		return false;
+
+	list_for_each_entry(sd, &notifier->done, async_list) {
+		struct v4l2_async_notifier *subdev_notifier =
+			v4l2_async_find_subdev_notifier(sd);
+
+		if (subdev_notifier &&
+		    !v4l2_async_notifier_can_complete(subdev_notifier))
+			return false;
+	}
+
+	return true;
+}
+
+/*
+ * Complete the master notifier if possible. This is done when all async
+ * sub-devices have been bound; v4l2_device is also available then.
+ */
+static int v4l2_async_notifier_try_complete(
+	struct v4l2_async_notifier *notifier)
+{
+	/* Quick check whether there are still more sub-devices here. */
+	if (!list_empty(&notifier->waiting))
+		return 0;
+
+	/* Check the entire notifier tree; find the root notifier first. */
+	while (notifier->parent)
+		notifier = notifier->parent;
+
+	/* This is root if it has v4l2_dev. */
+	if (!notifier->v4l2_dev)
+		return 0;
+
+	/* Is everything ready? */
+	if (!v4l2_async_notifier_can_complete(notifier))
+		return 0;
+
+	return v4l2_async_notifier_call_complete(notifier);
+}
+
+static int v4l2_async_notifier_try_all_subdevs(
+	struct v4l2_async_notifier *notifier);
+
+static int v4l2_async_match_notify(struct v4l2_async_notifier *notifier,
+				   struct v4l2_device *v4l2_dev,
+				   struct v4l2_subdev *sd,
+				   struct v4l2_async_subdev *asd)
+{
+	struct v4l2_async_notifier *subdev_notifier;
+	int ret;
+
+	ret = v4l2_device_register_subdev(v4l2_dev, sd);
+	if (ret < 0)
+		return ret;
+
+	ret = v4l2_async_notifier_call_bound(notifier, sd, asd);
+	if (ret < 0) {
+		v4l2_device_unregister_subdev(sd);
+		return ret;
+	}
+
+	/* Remove from the waiting list */
+	list_del(&asd->list);
+	sd->asd = asd;
+	sd->notifier = notifier;
+
+	/* Move from the global subdevice list to notifier's done */
+	list_move(&sd->async_list, &notifier->done);
+
+	/*
+	 * See if the sub-device has a notifier. If not, return here.
+	 */
+	subdev_notifier = v4l2_async_find_subdev_notifier(sd);
+	if (!subdev_notifier || subdev_notifier->parent)
+		return 0;
+
+	/*
+	 * Proceed with checking for the sub-device notifier's async
+	 * sub-devices, and return the result. The error will be handled by the
+	 * caller.
+	 */
+	subdev_notifier->parent = notifier;
+
+	return v4l2_async_notifier_try_all_subdevs(subdev_notifier);
+}
+
+/* Test all async sub-devices in a notifier for a match. */
+static int v4l2_async_notifier_try_all_subdevs(
+	struct v4l2_async_notifier *notifier)
+{
+	struct v4l2_device *v4l2_dev =
+		v4l2_async_notifier_find_v4l2_dev(notifier);
+	struct v4l2_subdev *sd;
+
+	if (!v4l2_dev)
+		return 0;
+
+again:
+	list_for_each_entry(sd, &subdev_list, async_list) {
+		struct v4l2_async_subdev *asd;
+		int ret;
+
+		asd = v4l2_async_find_match(notifier, sd);
+		if (!asd)
+			continue;
+
+		ret = v4l2_async_match_notify(notifier, v4l2_dev, sd, asd);
+		if (ret < 0)
+			return ret;
+
+		/*
+		 * v4l2_async_match_notify() may lead to registering a
+		 * new notifier and thus changing the async subdevs
+		 * list. In order to proceed safely from here, restart
+		 * parsing the list from the beginning.
+		 */
+		goto again;
+	}
+
+	return 0;
+}
+
+static void v4l2_async_cleanup(struct v4l2_subdev *sd)
+{
+	v4l2_device_unregister_subdev(sd);
+	/* Subdevice driver will reprobe and put the subdev back onto the list */
+	list_del_init(&sd->async_list);
+	sd->asd = NULL;
+}
+
+/* Unbind all sub-devices in the notifier tree. */
+static void v4l2_async_notifier_unbind_all_subdevs(
+	struct v4l2_async_notifier *notifier)
+{
+	struct v4l2_subdev *sd, *tmp;
+
+	list_for_each_entry_safe(sd, tmp, &notifier->done, async_list) {
+		struct v4l2_async_notifier *subdev_notifier =
+			v4l2_async_find_subdev_notifier(sd);
+
+		if (subdev_notifier)
+			v4l2_async_notifier_unbind_all_subdevs(subdev_notifier);
+
+		v4l2_async_notifier_call_unbind(notifier, sd, sd->asd);
+		v4l2_async_cleanup(sd);
+
+		list_move(&sd->async_list, &subdev_list);
+	}
+
+	notifier->parent = NULL;
+}
+
+/* See if an fwnode can be found in a notifier's lists. */
+static bool __v4l2_async_notifier_fwnode_has_async_subdev(
+	struct v4l2_async_notifier *notifier, struct fwnode_handle *fwnode)
+{
+	struct v4l2_async_subdev *asd;
+	struct v4l2_subdev *sd;
+
+	list_for_each_entry(asd, &notifier->waiting, list) {
+		if (asd->match_type != V4L2_ASYNC_MATCH_FWNODE)
+			continue;
+
+		if (asd->match.fwnode == fwnode)
+			return true;
+	}
+
+	list_for_each_entry(sd, &notifier->done, async_list) {
+		if (WARN_ON(!sd->asd))
+			continue;
+
+		if (sd->asd->match_type != V4L2_ASYNC_MATCH_FWNODE)
+			continue;
+
+		if (sd->asd->match.fwnode == fwnode)
+			return true;
+	}
+
+	return false;
+}
+
+/*
+ * Find out whether an async sub-device was set up for an fwnode already or
+ * whether it exists in a given notifier before @this_index.
+ */
+static bool v4l2_async_notifier_fwnode_has_async_subdev(
+	struct v4l2_async_notifier *notifier, struct fwnode_handle *fwnode,
+	unsigned int this_index)
+{
+	unsigned int j;
+
+	lockdep_assert_held(&list_lock);
+
+	/* Check that an fwnode is not being added more than once. */
+	for (j = 0; j < this_index; j++) {
+		struct v4l2_async_subdev *asd = notifier->subdevs[this_index];
+		struct v4l2_async_subdev *other_asd = notifier->subdevs[j];
+
+		if (other_asd->match_type == V4L2_ASYNC_MATCH_FWNODE &&
+		    asd->match.fwnode ==
+		    other_asd->match.fwnode)
+			return true;
+	}
+
+	/* Check than an fwnode did not exist in other notifiers. */
+	list_for_each_entry(notifier, &notifier_list, list)
+		if (__v4l2_async_notifier_fwnode_has_async_subdev(
+			    notifier, fwnode))
+			return true;
+
+	return false;
+}
+
+static int __v4l2_async_notifier_register(struct v4l2_async_notifier *notifier)
+{
+	struct device *dev =
+		notifier->v4l2_dev ? notifier->v4l2_dev->dev : NULL;
+	struct v4l2_async_subdev *asd;
+	int ret;
+	int i;
+
+	if (notifier->num_subdevs > V4L2_MAX_SUBDEVS)
+		return -EINVAL;
+
+	INIT_LIST_HEAD(&notifier->waiting);
+	INIT_LIST_HEAD(&notifier->done);
+
+	mutex_lock(&list_lock);
+
+	for (i = 0; i < notifier->num_subdevs; i++) {
+		asd = notifier->subdevs[i];
+
+		switch (asd->match_type) {
+		case V4L2_ASYNC_MATCH_CUSTOM:
+		case V4L2_ASYNC_MATCH_DEVNAME:
+		case V4L2_ASYNC_MATCH_I2C:
+			break;
+		case V4L2_ASYNC_MATCH_FWNODE:
+			if (v4l2_async_notifier_fwnode_has_async_subdev(
+				    notifier, asd->match.fwnode, i)) {
+				dev_err(dev,
+					"fwnode has already been registered or in notifier's subdev list\n");
+				ret = -EEXIST;
+				goto err_unlock;
+			}
+			break;
+		default:
+			dev_err(dev, "Invalid match type %u on %p\n",
+				asd->match_type, asd);
+			ret = -EINVAL;
+			goto err_unlock;
+		}
+		list_add_tail(&asd->list, &notifier->waiting);
+	}
+
+	ret = v4l2_async_notifier_try_all_subdevs(notifier);
+	if (ret < 0)
+		goto err_unbind;
+
+	ret = v4l2_async_notifier_try_complete(notifier);
+	if (ret < 0)
+		goto err_unbind;
+
+	/* Keep also completed notifiers on the list */
+	list_add(&notifier->list, &notifier_list);
+
+	mutex_unlock(&list_lock);
+
+	return 0;
+
+err_unbind:
+	/*
+	 * On failure, unbind all sub-devices registered through this notifier.
+	 */
+	v4l2_async_notifier_unbind_all_subdevs(notifier);
+
+err_unlock:
+	mutex_unlock(&list_lock);
+
+	return ret;
+}
+
+int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
+				 struct v4l2_async_notifier *notifier)
+{
+	int ret;
+
+	if (WARN_ON(!v4l2_dev || notifier->sd))
+		return -EINVAL;
+
+	notifier->v4l2_dev = v4l2_dev;
+
+	ret = __v4l2_async_notifier_register(notifier);
+	if (ret)
+		notifier->v4l2_dev = NULL;
+
+	return ret;
+}
+EXPORT_SYMBOL(v4l2_async_notifier_register);
+
+int v4l2_async_subdev_notifier_register(struct v4l2_subdev *sd,
+					struct v4l2_async_notifier *notifier)
+{
+	int ret;
+
+	if (WARN_ON(!sd || notifier->v4l2_dev))
+		return -EINVAL;
+
+	notifier->sd = sd;
+
+	ret = __v4l2_async_notifier_register(notifier);
+	if (ret)
+		notifier->sd = NULL;
+
+	return ret;
+}
+EXPORT_SYMBOL(v4l2_async_subdev_notifier_register);
+
+static void __v4l2_async_notifier_unregister(
+	struct v4l2_async_notifier *notifier)
+{
+	if (!notifier || (!notifier->v4l2_dev && !notifier->sd))
+		return;
+
+	v4l2_async_notifier_unbind_all_subdevs(notifier);
+
+	notifier->sd = NULL;
+	notifier->v4l2_dev = NULL;
+
+	list_del(&notifier->list);
+}
+
+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, &notifier_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, &notifier->waiting);
+
+		v4l2_async_notifier_call_unbind(notifier, sd, sd->asd);
+	}
+
+	v4l2_async_cleanup(sd);
+
+	mutex_unlock(&list_lock);
+}
+EXPORT_SYMBOL(v4l2_async_unregister_subdev);