projects/linux·blob v2.6.18 · refs

267 lines · 6.0 KiB

1/*
2 * RTC subsystem, interface functions
3 *
4 * Copyright (C) 2005 Tower Technologies
5 * Author: Alessandro Zummo <[email protected]>
6 *
7 * based on arch/arm/common/rtctime.c
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12*/
13
14#include <linux/rtc.h>
15
16int rtc_read_time(struct class_device *class_dev, struct rtc_time *tm)
17{
18 int err;
19 struct rtc_device *rtc = to_rtc_device(class_dev);
20
21 err = mutex_lock_interruptible(&rtc->ops_lock);
22 if (err)
23 return -EBUSY;
24
25 if (!rtc->ops)
26 err = -ENODEV;
27 else if (!rtc->ops->read_time)
28 err = -EINVAL;
29 else {
30 memset(tm, 0, sizeof(struct rtc_time));
31 err = rtc->ops->read_time(class_dev->dev, tm);
32 }
33
34 mutex_unlock(&rtc->ops_lock);
35 return err;
36}
37EXPORT_SYMBOL_GPL(rtc_read_time);
38
39int rtc_set_time(struct class_device *class_dev, struct rtc_time *tm)
40{
41 int err;
42 struct rtc_device *rtc = to_rtc_device(class_dev);
43
44 err = rtc_valid_tm(tm);
45 if (err != 0)
46 return err;
47
48 err = mutex_lock_interruptible(&rtc->ops_lock);
49 if (err)
50 return -EBUSY;
51
52 if (!rtc->ops)
53 err = -ENODEV;
54 else if (!rtc->ops->set_time)
55 err = -EINVAL;
56 else
57 err = rtc->ops->set_time(class_dev->dev, tm);
58
59 mutex_unlock(&rtc->ops_lock);
60 return err;
61}
62EXPORT_SYMBOL_GPL(rtc_set_time);
63
64int rtc_set_mmss(struct class_device *class_dev, unsigned long secs)
65{
66 int err;
67 struct rtc_device *rtc = to_rtc_device(class_dev);
68
69 err = mutex_lock_interruptible(&rtc->ops_lock);
70 if (err)
71 return -EBUSY;
72
73 if (!rtc->ops)
74 err = -ENODEV;
75 else if (rtc->ops->set_mmss)
76 err = rtc->ops->set_mmss(class_dev->dev, secs);
77 else if (rtc->ops->read_time && rtc->ops->set_time) {
78 struct rtc_time new, old;
79
80 err = rtc->ops->read_time(class_dev->dev, &old);
81 if (err == 0) {
82 rtc_time_to_tm(secs, &new);
83
84 /*
85 * avoid writing when we're going to change the day of
86 * the month. We will retry in the next minute. This
87 * basically means that if the RTC must not drift
88 * by more than 1 minute in 11 minutes.
89 */
90 if (!((old.tm_hour == 23 && old.tm_min == 59) ||
91 (new.tm_hour == 23 && new.tm_min == 59)))
92 err = rtc->ops->set_time(class_dev->dev, &new);
93 }
94 }
95 else
96 err = -EINVAL;
97
98 mutex_unlock(&rtc->ops_lock);
99
100 return err;
101}
102EXPORT_SYMBOL_GPL(rtc_set_mmss);
103
104int rtc_read_alarm(struct class_device *class_dev, struct rtc_wkalrm *alarm)
105{
106 int err;
107 struct rtc_device *rtc = to_rtc_device(class_dev);
108
109 err = mutex_lock_interruptible(&rtc->ops_lock);
110 if (err)
111 return -EBUSY;
112
113 if (rtc->ops == NULL)
114 err = -ENODEV;
115 else if (!rtc->ops->read_alarm)
116 err = -EINVAL;
117 else {
118 memset(alarm, 0, sizeof(struct rtc_wkalrm));
119 err = rtc->ops->read_alarm(class_dev->dev, alarm);
120 }
121
122 mutex_unlock(&rtc->ops_lock);
123 return err;
124}
125EXPORT_SYMBOL_GPL(rtc_read_alarm);
126
127int rtc_set_alarm(struct class_device *class_dev, struct rtc_wkalrm *alarm)
128{
129 int err;
130 struct rtc_device *rtc = to_rtc_device(class_dev);
131
132 err = mutex_lock_interruptible(&rtc->ops_lock);
133 if (err)
134 return -EBUSY;
135
136 if (!rtc->ops)
137 err = -ENODEV;
138 else if (!rtc->ops->set_alarm)
139 err = -EINVAL;
140 else
141 err = rtc->ops->set_alarm(class_dev->dev, alarm);
142
143 mutex_unlock(&rtc->ops_lock);
144 return err;
145}
146EXPORT_SYMBOL_GPL(rtc_set_alarm);
147
148void rtc_update_irq(struct class_device *class_dev,
149 unsigned long num, unsigned long events)
150{
151 struct rtc_device *rtc = to_rtc_device(class_dev);
152
153 spin_lock(&rtc->irq_lock);
154 rtc->irq_data = (rtc->irq_data + (num << 8)) | events;
155 spin_unlock(&rtc->irq_lock);
156
157 spin_lock(&rtc->irq_task_lock);
158 if (rtc->irq_task)
159 rtc->irq_task->func(rtc->irq_task->private_data);
160 spin_unlock(&rtc->irq_task_lock);
161
162 wake_up_interruptible(&rtc->irq_queue);
163 kill_fasync(&rtc->async_queue, SIGIO, POLL_IN);
164}
165EXPORT_SYMBOL_GPL(rtc_update_irq);
166
167struct class_device *rtc_class_open(char *name)
168{
169 struct class_device *class_dev = NULL,
170 *class_dev_tmp;
171
172 down(&rtc_class->sem);
173 list_for_each_entry(class_dev_tmp, &rtc_class->children, node) {
174 if (strncmp(class_dev_tmp->class_id, name, BUS_ID_SIZE) == 0) {
175 class_dev = class_dev_tmp;
176 break;
177 }
178 }
179
180 if (class_dev) {
181 if (!try_module_get(to_rtc_device(class_dev)->owner))
182 class_dev = NULL;
183 }
184 up(&rtc_class->sem);
185
186 return class_dev;
187}
188EXPORT_SYMBOL_GPL(rtc_class_open);
189
190void rtc_class_close(struct class_device *class_dev)
191{
192 module_put(to_rtc_device(class_dev)->owner);
193}
194EXPORT_SYMBOL_GPL(rtc_class_close);
195
196int rtc_irq_register(struct class_device *class_dev, struct rtc_task *task)
197{
198 int retval = -EBUSY;
199 struct rtc_device *rtc = to_rtc_device(class_dev);
200
201 if (task == NULL || task->func == NULL)
202 return -EINVAL;
203
204 spin_lock(&rtc->irq_task_lock);
205 if (rtc->irq_task == NULL) {
206 rtc->irq_task = task;
207 retval = 0;
208 }
209 spin_unlock(&rtc->irq_task_lock);
210
211 return retval;
212}
213EXPORT_SYMBOL_GPL(rtc_irq_register);
214
215void rtc_irq_unregister(struct class_device *class_dev, struct rtc_task *task)
216{
217 struct rtc_device *rtc = to_rtc_device(class_dev);
218
219 spin_lock(&rtc->irq_task_lock);
220 if (rtc->irq_task == task)
221 rtc->irq_task = NULL;
222 spin_unlock(&rtc->irq_task_lock);
223}
224EXPORT_SYMBOL_GPL(rtc_irq_unregister);
225
226int rtc_irq_set_state(struct class_device *class_dev, struct rtc_task *task, int enabled)
227{
228 int err = 0;
229 unsigned long flags;
230 struct rtc_device *rtc = to_rtc_device(class_dev);
231
232 if (rtc->ops->irq_set_state == NULL)
233 return -ENXIO;
234
235 spin_lock_irqsave(&rtc->irq_task_lock, flags);
236 if (rtc->irq_task != task)
237 err = -ENXIO;
238 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
239
240 if (err == 0)
241 err = rtc->ops->irq_set_state(class_dev->dev, enabled);
242
243 return err;
244}
245EXPORT_SYMBOL_GPL(rtc_irq_set_state);
246
247int rtc_irq_set_freq(struct class_device *class_dev, struct rtc_task *task, int freq)
248{
249 int err = 0;
250 unsigned long flags;
251 struct rtc_device *rtc = to_rtc_device(class_dev);
252
253 if (rtc->ops->irq_set_freq == NULL)
254 return -ENXIO;
255
256 spin_lock_irqsave(&rtc->irq_task_lock, flags);
257 if (rtc->irq_task != task)
258 err = -ENXIO;
259 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
260
261 if (err == 0) {
262 err = rtc->ops->irq_set_freq(class_dev->dev, freq);
263 if (err == 0)
264 rtc->irq_freq = freq;
265 }
266 return err;
267}