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>
20 #include "../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
;
32 static int iio_trig_periodic_rtc_set_state(struct iio_trigger
*trig
, bool state
)
34 struct iio_prtc_trigger_info
*trig_info
= trig
->private_data
;
35 if (trig_info
->frequency
== 0)
37 printk(KERN_INFO
"trigger frequency is %d\n", trig_info
->frequency
);
38 return rtc_irq_set_state(trig_info
->rtc
, &trig_info
->task
, state
);
41 static ssize_t
iio_trig_periodic_read_freq(struct device
*dev
,
42 struct device_attribute
*attr
,
45 struct iio_trigger
*trig
= dev_get_drvdata(dev
);
46 struct iio_prtc_trigger_info
*trig_info
= trig
->private_data
;
47 return sprintf(buf
, "%u\n", trig_info
->frequency
);
50 static ssize_t
iio_trig_periodic_write_freq(struct device
*dev
,
51 struct device_attribute
*attr
,
55 struct iio_trigger
*trig
= dev_get_drvdata(dev
);
56 struct iio_prtc_trigger_info
*trig_info
= trig
->private_data
;
60 ret
= strict_strtoul(buf
, 10, &val
);
64 ret
= rtc_irq_set_freq(trig_info
->rtc
, &trig_info
->task
, val
);
68 trig_info
->frequency
= val
;
76 static ssize_t
iio_trig_periodic_read_name(struct device
*dev
,
77 struct device_attribute
*attr
,
80 struct iio_trigger
*trig
= dev_get_drvdata(dev
);
81 struct iio_prtc_trigger_info
*trig_info
= trig
->private_data
;
82 return sprintf(buf
, "%s\n", trig_info
->name
);
85 static DEVICE_ATTR(name
, S_IRUGO
,
86 iio_trig_periodic_read_name
,
88 static DEVICE_ATTR(frequency
, S_IRUGO
| S_IWUSR
,
89 iio_trig_periodic_read_freq
,
90 iio_trig_periodic_write_freq
);
92 static struct attribute
*iio_trig_prtc_attrs
[] = {
93 &dev_attr_frequency
.attr
,
97 static const struct attribute_group iio_trig_prtc_attr_group
= {
98 .attrs
= iio_trig_prtc_attrs
,
101 static void iio_prtc_trigger_poll(void *private_data
)
103 iio_trigger_poll(private_data
);
106 static int iio_trig_periodic_rtc_probe(struct platform_device
*dev
)
108 char **pdata
= dev
->dev
.platform_data
;
109 struct iio_prtc_trigger_info
*trig_info
;
110 struct iio_trigger
*trig
, *trig2
;
115 if (pdata
[i
] == NULL
)
117 trig
= iio_allocate_trigger();
120 goto error_free_completed_registrations
;
122 list_add(&trig
->alloc_list
, &iio_prtc_trigger_list
);
124 trig_info
= kzalloc(sizeof(*trig_info
), GFP_KERNEL
);
127 goto error_put_trigger_and_remove_from_list
;
129 trig
->private_data
= trig_info
;
130 trig
->owner
= THIS_MODULE
;
131 trig
->set_trigger_state
= &iio_trig_periodic_rtc_set_state
;
132 trig
->name
= kmalloc(IIO_TRIGGER_NAME_LENGTH
, GFP_KERNEL
);
133 if (trig
->name
== NULL
) {
135 goto error_free_trig_info
;
137 snprintf((char *)trig
->name
,
138 IIO_TRIGGER_NAME_LENGTH
,
141 trig_info
->name
= (char *)trig
->name
;
144 = rtc_class_open(pdata
[i
]);
145 if (trig_info
->rtc
== NULL
) {
147 goto error_free_name
;
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
->control_attrs
= &iio_trig_prtc_attr_group
;
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
);
166 error_free_trig_info
:
168 error_put_trigger_and_remove_from_list
:
169 list_del(&trig
->alloc_list
);
170 iio_put_trigger(trig
);
171 error_free_completed_registrations
:
172 list_for_each_entry_safe(trig
,
174 &iio_prtc_trigger_list
,
176 trig_info
= trig
->private_data
;
177 rtc_irq_unregister(trig_info
->rtc
, &trig_info
->task
);
178 rtc_class_close(trig_info
->rtc
);
181 iio_trigger_unregister(trig
);
186 static int iio_trig_periodic_rtc_remove(struct platform_device
*dev
)
188 struct iio_trigger
*trig
, *trig2
;
189 struct iio_prtc_trigger_info
*trig_info
;
190 mutex_lock(&iio_prtc_trigger_list_lock
);
191 list_for_each_entry_safe(trig
,
193 &iio_prtc_trigger_list
,
195 trig_info
= trig
->private_data
;
196 rtc_irq_unregister(trig_info
->rtc
, &trig_info
->task
);
197 rtc_class_close(trig_info
->rtc
);
200 iio_trigger_unregister(trig
);
202 mutex_unlock(&iio_prtc_trigger_list_lock
);
206 static struct platform_driver iio_trig_periodic_rtc_driver
= {
207 .probe
= iio_trig_periodic_rtc_probe
,
208 .remove
= iio_trig_periodic_rtc_remove
,
210 .name
= "iio_prtc_trigger",
211 .owner
= THIS_MODULE
,
215 static int __init
iio_trig_periodic_rtc_init(void)
217 return platform_driver_register(&iio_trig_periodic_rtc_driver
);
220 static void __exit
iio_trig_periodic_rtc_exit(void)
222 return platform_driver_unregister(&iio_trig_periodic_rtc_driver
);
225 module_init(iio_trig_periodic_rtc_init
);
226 module_exit(iio_trig_periodic_rtc_exit
);
227 MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>");
228 MODULE_DESCRIPTION("Periodic realtime clock trigger for the iio subsystem");
229 MODULE_LICENSE("GPL v2");