1 /* The industrial I/O periodic RTC trigger driver
3 * Copyright (c) 2008 Jonathan Cameron
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 as published by
7 * the Free Software Foundation.
9 * This is a heavily rewritten version of the periodic timer system in
10 * earlier version of industrialio. It supplies the same functionality
11 * but via a trigger rather than a specific periodic timer system.
14 #include <linux/platform_device.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/slab.h>
18 #include <linux/rtc.h>
19 #include <linux/iio/iio.h>
20 #include <linux/iio/trigger.h>
22 static LIST_HEAD(iio_prtc_trigger_list);
23 static DEFINE_MUTEX(iio_prtc_trigger_list_lock);
25 struct iio_prtc_trigger_info {
26 struct rtc_device *rtc;
27 unsigned int frequency;
32 static int iio_trig_periodic_rtc_set_state(struct iio_trigger *trig, bool state)
34 struct iio_prtc_trigger_info *trig_info = iio_trigger_get_drvdata(trig);
37 if (trig_info->frequency == 0 && state)
39 dev_dbg(&trig_info->rtc->dev, "trigger frequency is %u\n",
40 trig_info->frequency);
41 ret = rtc_irq_set_state(trig_info->rtc, &trig_info->task, state);
43 trig_info->state = state;
48 static ssize_t iio_trig_periodic_read_freq(struct device *dev,
49 struct device_attribute *attr,
52 struct iio_trigger *trig = to_iio_trigger(dev);
53 struct iio_prtc_trigger_info *trig_info = iio_trigger_get_drvdata(trig);
55 return sprintf(buf, "%u\n", trig_info->frequency);
58 static ssize_t iio_trig_periodic_write_freq(struct device *dev,
59 struct device_attribute *attr,
63 struct iio_trigger *trig = to_iio_trigger(dev);
64 struct iio_prtc_trigger_info *trig_info = iio_trigger_get_drvdata(trig);
68 ret = kstrtouint(buf, 10, &val);
73 ret = rtc_irq_set_freq(trig_info->rtc, &trig_info->task, val);
74 if (ret == 0 && trig_info->state && trig_info->frequency == 0)
75 ret = rtc_irq_set_state(trig_info->rtc,
78 ret = rtc_irq_set_state(trig_info->rtc, &trig_info->task, 0);
82 trig_info->frequency = val;
90 static DEVICE_ATTR(frequency, S_IRUGO | S_IWUSR,
91 iio_trig_periodic_read_freq,
92 iio_trig_periodic_write_freq);
94 static struct attribute *iio_trig_prtc_attrs[] = {
95 &dev_attr_frequency.attr,
99 static const struct attribute_group iio_trig_prtc_attr_group = {
100 .attrs = iio_trig_prtc_attrs,
103 static const struct attribute_group *iio_trig_prtc_attr_groups[] = {
104 &iio_trig_prtc_attr_group,
108 static void iio_prtc_trigger_poll(void *private_data)
110 iio_trigger_poll(private_data);
113 static const struct iio_trigger_ops iio_prtc_trigger_ops = {
114 .owner = THIS_MODULE,
115 .set_trigger_state = &iio_trig_periodic_rtc_set_state,
118 static int iio_trig_periodic_rtc_probe(struct platform_device *dev)
120 char **pdata = dev->dev.platform_data;
121 struct iio_prtc_trigger_info *trig_info;
122 struct iio_trigger *trig, *trig2;
129 trig = iio_trigger_alloc("periodic%s", pdata[i]);
132 goto error_free_completed_registrations;
134 list_add(&trig->alloc_list, &iio_prtc_trigger_list);
136 trig_info = kzalloc(sizeof(*trig_info), GFP_KERNEL);
139 goto error_put_trigger_and_remove_from_list;
141 iio_trigger_set_drvdata(trig, trig_info);
142 trig->ops = &iio_prtc_trigger_ops;
144 trig_info->rtc = rtc_class_open(pdata[i]);
145 if (!trig_info->rtc) {
147 goto error_free_trig_info;
149 trig_info->task.func = iio_prtc_trigger_poll;
150 trig_info->task.private_data = trig;
151 ret = rtc_irq_register(trig_info->rtc, &trig_info->task);
153 goto error_close_rtc;
154 trig->dev.groups = iio_trig_prtc_attr_groups;
155 ret = iio_trigger_register(trig);
157 goto error_unregister_rtc_irq;
160 error_unregister_rtc_irq:
161 rtc_irq_unregister(trig_info->rtc, &trig_info->task);
163 rtc_class_close(trig_info->rtc);
164 error_free_trig_info:
166 error_put_trigger_and_remove_from_list:
167 list_del(&trig->alloc_list);
168 iio_trigger_put(trig);
169 error_free_completed_registrations:
170 list_for_each_entry_safe(trig,
172 &iio_prtc_trigger_list,
174 trig_info = iio_trigger_get_drvdata(trig);
175 rtc_irq_unregister(trig_info->rtc, &trig_info->task);
176 rtc_class_close(trig_info->rtc);
178 iio_trigger_unregister(trig);
183 static int iio_trig_periodic_rtc_remove(struct platform_device *dev)
185 struct iio_trigger *trig, *trig2;
186 struct iio_prtc_trigger_info *trig_info;
188 mutex_lock(&iio_prtc_trigger_list_lock);
189 list_for_each_entry_safe(trig,
191 &iio_prtc_trigger_list,
193 trig_info = iio_trigger_get_drvdata(trig);
194 rtc_irq_unregister(trig_info->rtc, &trig_info->task);
195 rtc_class_close(trig_info->rtc);
197 iio_trigger_unregister(trig);
199 mutex_unlock(&iio_prtc_trigger_list_lock);
203 static struct platform_driver iio_trig_periodic_rtc_driver = {
204 .probe = iio_trig_periodic_rtc_probe,
205 .remove = iio_trig_periodic_rtc_remove,
207 .name = "iio_prtc_trigger",
211 module_platform_driver(iio_trig_periodic_rtc_driver);
213 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
214 MODULE_DESCRIPTION("Periodic realtime clock trigger for the iio subsystem");
215 MODULE_LICENSE("GPL v2");