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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 | /* 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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