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/* The industrial I/O periodic RTC trigger driver
*
* Copyright (c) 2008 Jonathan Cameron
*
* 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.
*
* This is a heavily rewritten version of the periodic timer system in
* earlier version of industrialio. It supplies the same functionality
* but via a trigger rather than a specific periodic timer system.
*/
#include <linux/platform_device.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/rtc.h>
#include <linux/iio/iio.h>
#include <linux/iio/trigger.h>
static LIST_HEAD(iio_prtc_trigger_list);
static DEFINE_MUTEX(iio_prtc_trigger_list_lock);
struct iio_prtc_trigger_info {
struct rtc_device *rtc;
int frequency;
struct rtc_task task;
};
static int iio_trig_periodic_rtc_set_state(struct iio_trigger *trig, bool state)
{
struct iio_prtc_trigger_info *trig_info = trig->private_data;
if (trig_info->frequency == 0)
return -EINVAL;
printk(KERN_INFO "trigger frequency is %d\n", trig_info->frequency);
return rtc_irq_set_state(trig_info->rtc, &trig_info->task, state);
}
static ssize_t iio_trig_periodic_read_freq(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_trigger *trig = to_iio_trigger(dev);
struct iio_prtc_trigger_info *trig_info = trig->private_data;
return sprintf(buf, "%u\n", trig_info->frequency);
}
static ssize_t iio_trig_periodic_write_freq(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len)
{
struct iio_trigger *trig = to_iio_trigger(dev);
struct iio_prtc_trigger_info *trig_info = trig->private_data;
unsigned long val;
int ret;
ret = strict_strtoul(buf, 10, &val);
if (ret)
goto error_ret;
ret = rtc_irq_set_freq(trig_info->rtc, &trig_info->task, val);
if (ret)
goto error_ret;
trig_info->frequency = val;
return len;
error_ret:
return ret;
}
static DEVICE_ATTR(frequency, S_IRUGO | S_IWUSR,
iio_trig_periodic_read_freq,
iio_trig_periodic_write_freq);
static struct attribute *iio_trig_prtc_attrs[] = {
&dev_attr_frequency.attr,
NULL,
};
static const struct attribute_group iio_trig_prtc_attr_group = {
.attrs = iio_trig_prtc_attrs,
};
static const struct attribute_group *iio_trig_prtc_attr_groups[] = {
&iio_trig_prtc_attr_group,
NULL
};
static void iio_prtc_trigger_poll(void *private_data)
{
/* Timestamp is not provided currently */
iio_trigger_poll(private_data, 0);
}
static const struct iio_trigger_ops iio_prtc_trigger_ops = {
.owner = THIS_MODULE,
.set_trigger_state = &iio_trig_periodic_rtc_set_state,
};
static int __devinit iio_trig_periodic_rtc_probe(struct platform_device *dev)
{
char **pdata = dev->dev.platform_data;
struct iio_prtc_trigger_info *trig_info;
struct iio_trigger *trig, *trig2;
int i, ret;
for (i = 0;; i++) {
if (pdata[i] == NULL)
break;
trig = iio_trigger_alloc("periodic%s", pdata[i]);
if (!trig) {
ret = -ENOMEM;
goto error_free_completed_registrations;
}
list_add(&trig->alloc_list, &iio_prtc_trigger_list);
trig_info = kzalloc(sizeof(*trig_info), GFP_KERNEL);
if (!trig_info) {
ret = -ENOMEM;
goto error_put_trigger_and_remove_from_list;
}
trig->private_data = trig_info;
trig->ops = &iio_prtc_trigger_ops;
/* RTC access */
trig_info->rtc
= rtc_class_open(pdata[i]);
if (trig_info->rtc == NULL) {
ret = -EINVAL;
goto error_free_trig_info;
}
trig_info->task.func = iio_prtc_trigger_poll;
trig_info->task.private_data = trig;
ret = rtc_irq_register(trig_info->rtc, &trig_info->task);
if (ret)
goto error_close_rtc;
trig->dev.groups = iio_trig_prtc_attr_groups;
ret = iio_trigger_register(trig);
if (ret)
goto error_unregister_rtc_irq;
}
return 0;
error_unregister_rtc_irq:
rtc_irq_unregister(trig_info->rtc, &trig_info->task);
error_close_rtc:
rtc_class_close(trig_info->rtc);
error_free_trig_info:
kfree(trig_info);
error_put_trigger_and_remove_from_list:
list_del(&trig->alloc_list);
iio_trigger_put(trig);
error_free_completed_registrations:
list_for_each_entry_safe(trig,
trig2,
&iio_prtc_trigger_list,
alloc_list) {
trig_info = trig->private_data;
rtc_irq_unregister(trig_info->rtc, &trig_info->task);
rtc_class_close(trig_info->rtc);
kfree(trig_info);
iio_trigger_unregister(trig);
}
return ret;
}
static int __devexit iio_trig_periodic_rtc_remove(struct platform_device *dev)
{
struct iio_trigger *trig, *trig2;
struct iio_prtc_trigger_info *trig_info;
mutex_lock(&iio_prtc_trigger_list_lock);
list_for_each_entry_safe(trig,
trig2,
&iio_prtc_trigger_list,
alloc_list) {
trig_info = trig->private_data;
rtc_irq_unregister(trig_info->rtc, &trig_info->task);
rtc_class_close(trig_info->rtc);
kfree(trig_info);
iio_trigger_unregister(trig);
}
mutex_unlock(&iio_prtc_trigger_list_lock);
return 0;
}
static struct platform_driver iio_trig_periodic_rtc_driver = {
.probe = iio_trig_periodic_rtc_probe,
.remove = __devexit_p(iio_trig_periodic_rtc_remove),
.driver = {
.name = "iio_prtc_trigger",
.owner = THIS_MODULE,
},
};
module_platform_driver(iio_trig_periodic_rtc_driver);
MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>");
MODULE_DESCRIPTION("Periodic realtime clock trigger for the iio subsystem");
MODULE_LICENSE("GPL v2");
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