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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright 2011 Analog Devices Inc.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/irq_work.h>
#include <linux/iio/iio.h>
#include <linux/iio/trigger.h>
struct iio_sysfs_trig {
struct iio_trigger *trig;
struct irq_work work;
int id;
struct list_head l;
};
static LIST_HEAD(iio_sysfs_trig_list);
static DEFINE_MUTEX(iio_sysfs_trig_list_mut);
static int iio_sysfs_trigger_probe(int id);
static ssize_t iio_sysfs_trig_add(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len)
{
int ret;
unsigned long input;
ret = kstrtoul(buf, 10, &input);
if (ret)
return ret;
ret = iio_sysfs_trigger_probe(input);
if (ret)
return ret;
return len;
}
static DEVICE_ATTR(add_trigger, S_IWUSR, NULL, &iio_sysfs_trig_add);
static int iio_sysfs_trigger_remove(int id);
static ssize_t iio_sysfs_trig_remove(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len)
{
int ret;
unsigned long input;
ret = kstrtoul(buf, 10, &input);
if (ret)
return ret;
ret = iio_sysfs_trigger_remove(input);
if (ret)
return ret;
return len;
}
static DEVICE_ATTR(remove_trigger, S_IWUSR, NULL, &iio_sysfs_trig_remove);
static struct attribute *iio_sysfs_trig_attrs[] = {
&dev_attr_add_trigger.attr,
&dev_attr_remove_trigger.attr,
NULL,
};
static const struct attribute_group iio_sysfs_trig_group = {
.attrs = iio_sysfs_trig_attrs,
};
static const struct attribute_group *iio_sysfs_trig_groups[] = {
&iio_sysfs_trig_group,
NULL
};
/* Nothing to actually do upon release */
static void iio_trigger_sysfs_release(struct device *dev)
{
}
static struct device iio_sysfs_trig_dev = {
.bus = &iio_bus_type,
.groups = iio_sysfs_trig_groups,
.release = &iio_trigger_sysfs_release,
};
static void iio_sysfs_trigger_work(struct irq_work *work)
{
struct iio_sysfs_trig *trig = container_of(work, struct iio_sysfs_trig,
work);
iio_trigger_poll(trig->trig);
}
static ssize_t iio_sysfs_trigger_poll(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
struct iio_trigger *trig = to_iio_trigger(dev);
struct iio_sysfs_trig *sysfs_trig = iio_trigger_get_drvdata(trig);
irq_work_queue(&sysfs_trig->work);
return count;
}
static DEVICE_ATTR(trigger_now, S_IWUSR, NULL, iio_sysfs_trigger_poll);
static struct attribute *iio_sysfs_trigger_attrs[] = {
&dev_attr_trigger_now.attr,
NULL,
};
static const struct attribute_group iio_sysfs_trigger_attr_group = {
.attrs = iio_sysfs_trigger_attrs,
};
static const struct attribute_group *iio_sysfs_trigger_attr_groups[] = {
&iio_sysfs_trigger_attr_group,
NULL
};
static int iio_sysfs_trigger_probe(int id)
{
struct iio_sysfs_trig *t;
int ret;
bool foundit = false;
mutex_lock(&iio_sysfs_trig_list_mut);
list_for_each_entry(t, &iio_sysfs_trig_list, l)
if (id == t->id) {
foundit = true;
break;
}
if (foundit) {
ret = -EINVAL;
goto out1;
}
t = kmalloc(sizeof(*t), GFP_KERNEL);
if (t == NULL) {
ret = -ENOMEM;
goto out1;
}
t->id = id;
t->trig = iio_trigger_alloc(&iio_sysfs_trig_dev, "sysfstrig%d", id);
if (!t->trig) {
ret = -ENOMEM;
goto free_t;
}
t->trig->dev.groups = iio_sysfs_trigger_attr_groups;
iio_trigger_set_drvdata(t->trig, t);
t->work = IRQ_WORK_INIT_HARD(iio_sysfs_trigger_work);
ret = iio_trigger_register(t->trig);
if (ret)
goto out2;
list_add(&t->l, &iio_sysfs_trig_list);
__module_get(THIS_MODULE);
mutex_unlock(&iio_sysfs_trig_list_mut);
return 0;
out2:
iio_trigger_free(t->trig);
free_t:
kfree(t);
out1:
mutex_unlock(&iio_sysfs_trig_list_mut);
return ret;
}
static int iio_sysfs_trigger_remove(int id)
{
bool foundit = false;
struct iio_sysfs_trig *t;
mutex_lock(&iio_sysfs_trig_list_mut);
list_for_each_entry(t, &iio_sysfs_trig_list, l)
if (id == t->id) {
foundit = true;
break;
}
if (!foundit) {
mutex_unlock(&iio_sysfs_trig_list_mut);
return -EINVAL;
}
iio_trigger_unregister(t->trig);
irq_work_sync(&t->work);
iio_trigger_free(t->trig);
list_del(&t->l);
kfree(t);
module_put(THIS_MODULE);
mutex_unlock(&iio_sysfs_trig_list_mut);
return 0;
}
static int __init iio_sysfs_trig_init(void)
{
device_initialize(&iio_sysfs_trig_dev);
dev_set_name(&iio_sysfs_trig_dev, "iio_sysfs_trigger");
return device_add(&iio_sysfs_trig_dev);
}
module_init(iio_sysfs_trig_init);
static void __exit iio_sysfs_trig_exit(void)
{
device_unregister(&iio_sysfs_trig_dev);
}
module_exit(iio_sysfs_trig_exit);
MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
MODULE_DESCRIPTION("Sysfs based trigger for the iio subsystem");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:iio-trig-sysfs");
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