229 lines
6.0 KiB
C
229 lines
6.0 KiB
C
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/* The industrial I/O periodic RTC trigger driver
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*
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* Copyright (c) 2008 Jonathan Cameron
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*
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* This is a heavily rewritten version of the periodic timer system in
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* earlier version of industrialio. It supplies the same functionality
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* but via a trigger rather than a specific periodic timer system.
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*/
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#include <linux/platform_device.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/rtc.h>
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#include "../iio.h"
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#include "../trigger.h"
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LIST_HEAD(iio_prtc_trigger_list);
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DEFINE_MUTEX(iio_prtc_trigger_list_lock);
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struct iio_prtc_trigger_info {
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struct rtc_device *rtc;
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int frequency;
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char *name;
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struct rtc_task task;
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};
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static int iio_trig_periodic_rtc_set_state(struct iio_trigger *trig, bool state)
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{
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struct iio_prtc_trigger_info *trig_info = trig->private_data;
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if (trig_info->frequency == 0)
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return -EINVAL;
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printk(KERN_INFO "trigger frequency is %d\n", trig_info->frequency);
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return rtc_irq_set_state(trig_info->rtc, &trig_info->task, state);
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}
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static ssize_t iio_trig_periodic_read_freq(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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struct iio_trigger *trig = dev_get_drvdata(dev);
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struct iio_prtc_trigger_info *trig_info = trig->private_data;
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return sprintf(buf, "%u\n", trig_info->frequency);
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}
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static ssize_t iio_trig_periodic_write_freq(struct device *dev,
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struct device_attribute *attr,
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const char *buf,
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size_t len)
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{
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struct iio_trigger *trig = dev_get_drvdata(dev);
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struct iio_prtc_trigger_info *trig_info = trig->private_data;
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unsigned long val;
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int ret;
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ret = strict_strtoul(buf, 10, &val);
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if (ret)
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goto error_ret;
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ret = rtc_irq_set_freq(trig_info->rtc, &trig_info->task, val);
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if (ret)
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goto error_ret;
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trig_info->frequency = val;
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return len;
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error_ret:
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return ret;
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}
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static ssize_t iio_trig_periodic_read_name(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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struct iio_trigger *trig = dev_get_drvdata(dev);
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struct iio_prtc_trigger_info *trig_info = trig->private_data;
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return sprintf(buf, "%s\n", trig_info->name);
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}
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static DEVICE_ATTR(name, S_IRUGO,
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iio_trig_periodic_read_name,
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NULL);
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static DEVICE_ATTR(frequency, S_IRUGO | S_IWUSR,
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iio_trig_periodic_read_freq,
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iio_trig_periodic_write_freq);
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static struct attribute *iio_trig_prtc_attrs[] = {
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&dev_attr_frequency.attr,
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&dev_attr_name.attr,
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NULL,
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};
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static const struct attribute_group iio_trig_prtc_attr_group = {
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.attrs = iio_trig_prtc_attrs,
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};
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static void iio_prtc_trigger_poll(void *private_data)
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{
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iio_trigger_poll(private_data);
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}
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static int iio_trig_periodic_rtc_probe(struct platform_device *dev)
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{
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char **pdata = dev->dev.platform_data;
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struct iio_prtc_trigger_info *trig_info;
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struct iio_trigger *trig, *trig2;
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int i, ret;
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for (i = 0;; i++) {
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if (pdata[i] == NULL)
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break;
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trig = iio_allocate_trigger();
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if (!trig) {
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ret = -ENOMEM;
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goto error_free_completed_registrations;
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}
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list_add(&trig->alloc_list, &iio_prtc_trigger_list);
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trig_info = kzalloc(sizeof(*trig_info), GFP_KERNEL);
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if (!trig_info) {
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ret = -ENOMEM;
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goto error_put_trigger_and_remove_from_list;
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}
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trig->private_data = trig_info;
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trig->owner = THIS_MODULE;
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trig->set_trigger_state = &iio_trig_periodic_rtc_set_state;
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trig->name = kmalloc(IIO_TRIGGER_NAME_LENGTH, GFP_KERNEL);
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if (trig->name == NULL) {
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ret = -ENOMEM;
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goto error_free_trig_info;
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}
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snprintf((char *)trig->name,
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IIO_TRIGGER_NAME_LENGTH,
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"periodic%s",
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pdata[i]);
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trig_info->name = (char *)trig->name;
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/* RTC access */
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trig_info->rtc
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= rtc_class_open(pdata[i]);
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if (trig_info->rtc == NULL) {
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ret = -EINVAL;
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goto error_free_name;
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}
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trig_info->task.func = iio_prtc_trigger_poll;
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trig_info->task.private_data = trig;
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ret = rtc_irq_register(trig_info->rtc, &trig_info->task);
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if (ret)
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goto error_close_rtc;
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trig->control_attrs = &iio_trig_prtc_attr_group;
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ret = iio_trigger_register(trig);
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if (ret)
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goto error_unregister_rtc_irq;
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}
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return 0;
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error_unregister_rtc_irq:
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rtc_irq_unregister(trig_info->rtc, &trig_info->task);
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error_close_rtc:
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rtc_class_close(trig_info->rtc);
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error_free_name:
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kfree(trig->name);
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error_free_trig_info:
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kfree(trig_info);
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error_put_trigger_and_remove_from_list:
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list_del(&trig->alloc_list);
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iio_put_trigger(trig);
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error_free_completed_registrations:
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list_for_each_entry_safe(trig,
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trig2,
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&iio_prtc_trigger_list,
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alloc_list) {
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trig_info = trig->private_data;
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rtc_irq_unregister(trig_info->rtc, &trig_info->task);
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rtc_class_close(trig_info->rtc);
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kfree(trig->name);
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kfree(trig_info);
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iio_trigger_unregister(trig);
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}
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return ret;
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}
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static int iio_trig_periodic_rtc_remove(struct platform_device *dev)
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{
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struct iio_trigger *trig, *trig2;
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struct iio_prtc_trigger_info *trig_info;
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mutex_lock(&iio_prtc_trigger_list_lock);
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list_for_each_entry_safe(trig,
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trig2,
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&iio_prtc_trigger_list,
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alloc_list) {
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trig_info = trig->private_data;
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rtc_irq_unregister(trig_info->rtc, &trig_info->task);
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rtc_class_close(trig_info->rtc);
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kfree(trig->name);
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kfree(trig_info);
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iio_trigger_unregister(trig);
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}
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mutex_unlock(&iio_prtc_trigger_list_lock);
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return 0;
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}
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static struct platform_driver iio_trig_periodic_rtc_driver = {
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.probe = iio_trig_periodic_rtc_probe,
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.remove = iio_trig_periodic_rtc_remove,
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.driver = {
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.name = "iio_prtc_trigger",
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.owner = THIS_MODULE,
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},
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};
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static int __init iio_trig_periodic_rtc_init(void)
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{
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return platform_driver_register(&iio_trig_periodic_rtc_driver);
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}
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static void __exit iio_trig_periodic_rtc_exit(void)
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{
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return platform_driver_unregister(&iio_trig_periodic_rtc_driver);
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}
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module_init(iio_trig_periodic_rtc_init);
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module_exit(iio_trig_periodic_rtc_exit);
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MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>");
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MODULE_DESCRIPTION("Periodic realtime clock trigger for the iio subsystem");
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MODULE_LICENSE("GPL v2");
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