linux_dsm_epyc7002/drivers/media/v4l2-core/v4l2-async.c
Steve Longerbeam eae2aed1ea media: v4l2-fwnode: Switch to v4l2_async_notifier_add_subdev
The fwnode endpoint and reference parsing functions in v4l2-fwnode.c
are modified to make use of v4l2_async_notifier_add_subdev().
As a result the notifier->subdevs array is no longer allocated or
re-allocated, and by extension the max_subdevs value is also no
longer needed.

Callers of the fwnode endpoint and reference parsing functions must now
first initialize the notifier with a call to v4l2_async_notifier_init().
This includes the function v4l2_async_register_subdev_sensor_common(),
and the intel-ipu3, omap3isp, and rcar-vin drivers.

Since the notifier->subdevs array is no longer allocated in the
fwnode endpoint and reference parsing functions, the callers of
those functions must never reference that array, since it is now
NULL. Of the drivers that make use of the fwnode/ref parsing,
only the intel-ipu3 driver references the ->subdevs[] array,
(in the notifier completion callback), so that driver has been
modified to iterate through the notifier->asd_list instead.

Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-10-04 15:33:09 -04:00

815 lines
18 KiB
C

/*
* 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;
}
/* Compare two async sub-device descriptors for equivalence */
static bool asd_equal(struct v4l2_async_subdev *asd_x,
struct v4l2_async_subdev *asd_y)
{
if (asd_x->match_type != asd_y->match_type)
return false;
switch (asd_x->match_type) {
case V4L2_ASYNC_MATCH_DEVNAME:
return strcmp(asd_x->match.device_name,
asd_y->match.device_name) == 0;
case V4L2_ASYNC_MATCH_I2C:
return asd_x->match.i2c.adapter_id ==
asd_y->match.i2c.adapter_id &&
asd_x->match.i2c.address ==
asd_y->match.i2c.address;
case V4L2_ASYNC_MATCH_FWNODE:
return asd_x->match.fwnode == asd_y->match.fwnode;
default:
break;
}
return false;
}
/* 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 async sub-device can be found in a notifier's lists. */
static bool
__v4l2_async_notifier_has_async_subdev(struct v4l2_async_notifier *notifier,
struct v4l2_async_subdev *asd)
{
struct v4l2_async_subdev *asd_y;
struct v4l2_subdev *sd;
list_for_each_entry(asd_y, &notifier->waiting, list)
if (asd_equal(asd, asd_y))
return true;
list_for_each_entry(sd, &notifier->done, async_list) {
if (WARN_ON(!sd->asd))
continue;
if (asd_equal(asd, sd->asd))
return true;
}
return false;
}
/*
* Find out whether an async sub-device was set up already or
* whether it exists in a given notifier before @this_index.
*/
static bool
v4l2_async_notifier_has_async_subdev(struct v4l2_async_notifier *notifier,
struct v4l2_async_subdev *asd,
unsigned int this_index)
{
struct v4l2_async_subdev *asd_y;
unsigned int j;
lockdep_assert_held(&list_lock);
/* Check that an asd is not being added more than once. */
if (notifier->subdevs) {
for (j = 0; j < this_index; j++) {
asd_y = notifier->subdevs[j];
if (asd_equal(asd, asd_y))
return true;
}
} else {
j = 0;
list_for_each_entry(asd_y, &notifier->asd_list, asd_list) {
if (j++ >= this_index)
break;
if (asd_equal(asd, asd_y))
return true;
}
}
/* Check that an asd does not exist in other notifiers. */
list_for_each_entry(notifier, &notifier_list, list)
if (__v4l2_async_notifier_has_async_subdev(notifier, asd))
return true;
return false;
}
static int v4l2_async_notifier_asd_valid(struct v4l2_async_notifier *notifier,
struct v4l2_async_subdev *asd,
unsigned int this_index)
{
struct device *dev =
notifier->v4l2_dev ? notifier->v4l2_dev->dev : NULL;
if (!asd)
return -EINVAL;
switch (asd->match_type) {
case V4L2_ASYNC_MATCH_CUSTOM:
case V4L2_ASYNC_MATCH_DEVNAME:
case V4L2_ASYNC_MATCH_I2C:
case V4L2_ASYNC_MATCH_FWNODE:
if (v4l2_async_notifier_has_async_subdev(notifier, asd,
this_index)) {
dev_dbg(dev, "subdev descriptor already listed in this or other notifiers\n");
return -EEXIST;
}
break;
default:
dev_err(dev, "Invalid match type %u on %p\n",
asd->match_type, asd);
return -EINVAL;
}
return 0;
}
void v4l2_async_notifier_init(struct v4l2_async_notifier *notifier)
{
mutex_lock(&list_lock);
INIT_LIST_HEAD(&notifier->asd_list);
mutex_unlock(&list_lock);
}
EXPORT_SYMBOL(v4l2_async_notifier_init);
static int __v4l2_async_notifier_register(struct v4l2_async_notifier *notifier)
{
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);
if (notifier->subdevs) {
for (i = 0; i < notifier->num_subdevs; i++) {
asd = notifier->subdevs[i];
ret = v4l2_async_notifier_asd_valid(notifier, asd, i);
if (ret)
goto err_unlock;
list_add_tail(&asd->list, &notifier->waiting);
}
} else {
i = 0;
list_for_each_entry(asd, &notifier->asd_list, asd_list) {
ret = v4l2_async_notifier_asd_valid(notifier, asd, i++);
if (ret)
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);
static void __v4l2_async_notifier_cleanup(struct v4l2_async_notifier *notifier)
{
struct v4l2_async_subdev *asd, *tmp;
unsigned int i;
if (!notifier)
return;
if (notifier->subdevs) {
for (i = 0; i < notifier->num_subdevs; i++) {
asd = notifier->subdevs[i];
switch (asd->match_type) {
case V4L2_ASYNC_MATCH_FWNODE:
fwnode_handle_put(asd->match.fwnode);
break;
default:
break;
}
kfree(asd);
}
kvfree(notifier->subdevs);
notifier->subdevs = NULL;
} else {
list_for_each_entry_safe(asd, tmp,
&notifier->asd_list, asd_list) {
switch (asd->match_type) {
case V4L2_ASYNC_MATCH_FWNODE:
fwnode_handle_put(asd->match.fwnode);
break;
default:
break;
}
list_del(&asd->asd_list);
kfree(asd);
}
}
notifier->num_subdevs = 0;
}
void v4l2_async_notifier_cleanup(struct v4l2_async_notifier *notifier)
{
mutex_lock(&list_lock);
__v4l2_async_notifier_cleanup(notifier);
mutex_unlock(&list_lock);
}
EXPORT_SYMBOL_GPL(v4l2_async_notifier_cleanup);
int v4l2_async_notifier_add_subdev(struct v4l2_async_notifier *notifier,
struct v4l2_async_subdev *asd)
{
int ret;
mutex_lock(&list_lock);
if (notifier->num_subdevs >= V4L2_MAX_SUBDEVS) {
ret = -EINVAL;
goto unlock;
}
/*
* If caller uses this function, it cannot also allocate and
* place asd's in the notifier->subdevs array.
*/
if (WARN_ON(notifier->subdevs)) {
ret = -EINVAL;
goto unlock;
}
ret = v4l2_async_notifier_asd_valid(notifier, asd,
notifier->num_subdevs);
if (ret)
goto unlock;
list_add_tail(&asd->asd_list, &notifier->asd_list);
notifier->num_subdevs++;
unlock:
mutex_unlock(&list_lock);
return ret;
}
EXPORT_SYMBOL_GPL(v4l2_async_notifier_add_subdev);
struct v4l2_async_subdev *
v4l2_async_notifier_add_fwnode_subdev(struct v4l2_async_notifier *notifier,
struct fwnode_handle *fwnode,
unsigned int asd_struct_size)
{
struct v4l2_async_subdev *asd;
int ret;
asd = kzalloc(asd_struct_size, GFP_KERNEL);
if (!asd)
return ERR_PTR(-ENOMEM);
asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
asd->match.fwnode = fwnode;
ret = v4l2_async_notifier_add_subdev(notifier, asd);
if (ret) {
kfree(asd);
return ERR_PTR(ret);
}
return asd;
}
EXPORT_SYMBOL_GPL(v4l2_async_notifier_add_fwnode_subdev);
struct v4l2_async_subdev *
v4l2_async_notifier_add_i2c_subdev(struct v4l2_async_notifier *notifier,
int adapter_id, unsigned short address,
unsigned int asd_struct_size)
{
struct v4l2_async_subdev *asd;
int ret;
asd = kzalloc(asd_struct_size, GFP_KERNEL);
if (!asd)
return ERR_PTR(-ENOMEM);
asd->match_type = V4L2_ASYNC_MATCH_I2C;
asd->match.i2c.adapter_id = adapter_id;
asd->match.i2c.address = address;
ret = v4l2_async_notifier_add_subdev(notifier, asd);
if (ret) {
kfree(asd);
return ERR_PTR(ret);
}
return asd;
}
EXPORT_SYMBOL_GPL(v4l2_async_notifier_add_i2c_subdev);
struct v4l2_async_subdev *
v4l2_async_notifier_add_devname_subdev(struct v4l2_async_notifier *notifier,
const char *device_name,
unsigned int asd_struct_size)
{
struct v4l2_async_subdev *asd;
int ret;
asd = kzalloc(asd_struct_size, GFP_KERNEL);
if (!asd)
return ERR_PTR(-ENOMEM);
asd->match_type = V4L2_ASYNC_MATCH_DEVNAME;
asd->match.device_name = device_name;
ret = v4l2_async_notifier_add_subdev(notifier, asd);
if (ret) {
kfree(asd);
return ERR_PTR(ret);
}
return asd;
}
EXPORT_SYMBOL_GPL(v4l2_async_notifier_add_devname_subdev);
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);