+++ /dev/null
-/* 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;
- unsigned int frequency;
- struct rtc_task task;
- bool state;
-};
-
-static int iio_trig_periodic_rtc_set_state(struct iio_trigger *trig, bool state)
-{
- struct iio_prtc_trigger_info *trig_info = iio_trigger_get_drvdata(trig);
- int ret;
-
- if (trig_info->frequency == 0 && state)
- return -EINVAL;
- dev_dbg(&trig_info->rtc->dev, "trigger frequency is %u\n",
- trig_info->frequency);
- ret = rtc_irq_set_state(trig_info->rtc, &trig_info->task, state);
- if (!ret)
- trig_info->state = state;
-
- return ret;
-}
-
-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 = iio_trigger_get_drvdata(trig);
-
- 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 = iio_trigger_get_drvdata(trig);
- unsigned int val;
- int ret;
-
- ret = kstrtouint(buf, 10, &val);
- if (ret)
- goto error_ret;
-
- if (val > 0) {
- ret = rtc_irq_set_freq(trig_info->rtc, &trig_info->task, val);
- if (ret == 0 && trig_info->state && trig_info->frequency == 0)
- ret = rtc_irq_set_state(trig_info->rtc,
- &trig_info->task, 1);
- } else {
- ret = rtc_irq_set_state(trig_info->rtc, &trig_info->task, 0);
- }
- 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)
-{
- iio_trigger_poll(private_data);
-}
-
-static const struct iio_trigger_ops iio_prtc_trigger_ops = {
- .owner = THIS_MODULE,
- .set_trigger_state = &iio_trig_periodic_rtc_set_state,
-};
-
-static int 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])
- 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;
- }
- iio_trigger_set_drvdata(trig, trig_info);
- trig->ops = &iio_prtc_trigger_ops;
- /* RTC access */
- trig_info->rtc = rtc_class_open(pdata[i]);
- if (!trig_info->rtc) {
- 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 = iio_trigger_get_drvdata(trig);
- 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 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 = iio_trigger_get_drvdata(trig);
- 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 = iio_trig_periodic_rtc_remove,
- .driver = {
- .name = "iio_prtc_trigger",
- },
-};
-
-module_platform_driver(iio_trig_periodic_rtc_driver);
-
-MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
-MODULE_DESCRIPTION("Periodic realtime clock trigger for the iio subsystem");
-MODULE_LICENSE("GPL v2");
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