projects/linux·blob v2.6.21 · refs

276 lines · 6.4 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
148/**
149 * rtc_update_irq - report RTC periodic, alarm, and/or update irqs
150 * @class_dev: the rtc's class device
151 * @num: how many irqs are being reported (usually one)
152 * @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF
153 * Context: in_interrupt(), irqs blocked
154 */
155void rtc_update_irq(struct class_device *class_dev,
156 unsigned long num, unsigned long events)
157{
158 struct rtc_device *rtc = to_rtc_device(class_dev);
159
160 spin_lock(&rtc->irq_lock);
161 rtc->irq_data = (rtc->irq_data + (num << 8)) | events;
162 spin_unlock(&rtc->irq_lock);
163
164 spin_lock(&rtc->irq_task_lock);
165 if (rtc->irq_task)
166 rtc->irq_task->func(rtc->irq_task->private_data);
167 spin_unlock(&rtc->irq_task_lock);
168
169 wake_up_interruptible(&rtc->irq_queue);
170 kill_fasync(&rtc->async_queue, SIGIO, POLL_IN);
171}
172EXPORT_SYMBOL_GPL(rtc_update_irq);
173
174struct class_device *rtc_class_open(char *name)
175{
176 struct class_device *class_dev = NULL,
177 *class_dev_tmp;
178
179 down(&rtc_class->sem);
180 list_for_each_entry(class_dev_tmp, &rtc_class->children, node) {
181 if (strncmp(class_dev_tmp->class_id, name, BUS_ID_SIZE) == 0) {
182 class_dev = class_device_get(class_dev_tmp);
183 break;
184 }
185 }
186
187 if (class_dev) {
188 if (!try_module_get(to_rtc_device(class_dev)->owner))
189 class_dev = NULL;
190 }
191 up(&rtc_class->sem);
192
193 return class_dev;
194}
195EXPORT_SYMBOL_GPL(rtc_class_open);
196
197void rtc_class_close(struct class_device *class_dev)
198{
199 module_put(to_rtc_device(class_dev)->owner);
200 class_device_put(class_dev);
201}
202EXPORT_SYMBOL_GPL(rtc_class_close);
203
204int rtc_irq_register(struct class_device *class_dev, struct rtc_task *task)
205{
206 int retval = -EBUSY;
207 struct rtc_device *rtc = to_rtc_device(class_dev);
208
209 if (task == NULL || task->func == NULL)
210 return -EINVAL;
211
212 spin_lock_irq(&rtc->irq_task_lock);
213 if (rtc->irq_task == NULL) {
214 rtc->irq_task = task;
215 retval = 0;
216 }
217 spin_unlock_irq(&rtc->irq_task_lock);
218
219 return retval;
220}
221EXPORT_SYMBOL_GPL(rtc_irq_register);
222
223void rtc_irq_unregister(struct class_device *class_dev, struct rtc_task *task)
224{
225 struct rtc_device *rtc = to_rtc_device(class_dev);
226
227 spin_lock_irq(&rtc->irq_task_lock);
228 if (rtc->irq_task == task)
229 rtc->irq_task = NULL;
230 spin_unlock_irq(&rtc->irq_task_lock);
231}
232EXPORT_SYMBOL_GPL(rtc_irq_unregister);
233
234int rtc_irq_set_state(struct class_device *class_dev, struct rtc_task *task, int enabled)
235{
236 int err = 0;
237 unsigned long flags;
238 struct rtc_device *rtc = to_rtc_device(class_dev);
239
240 if (rtc->ops->irq_set_state == NULL)
241 return -ENXIO;
242
243 spin_lock_irqsave(&rtc->irq_task_lock, flags);
244 if (rtc->irq_task != task)
245 err = -ENXIO;
246 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
247
248 if (err == 0)
249 err = rtc->ops->irq_set_state(class_dev->dev, enabled);
250
251 return err;
252}
253EXPORT_SYMBOL_GPL(rtc_irq_set_state);
254
255int rtc_irq_set_freq(struct class_device *class_dev, struct rtc_task *task, int freq)
256{
257 int err = 0;
258 unsigned long flags;
259 struct rtc_device *rtc = to_rtc_device(class_dev);
260
261 if (rtc->ops->irq_set_freq == NULL)
262 return -ENXIO;
263
264 spin_lock_irqsave(&rtc->irq_task_lock, flags);
265 if (rtc->irq_task != task)
266 err = -ENXIO;
267 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
268
269 if (err == 0) {
270 err = rtc->ops->irq_set_freq(class_dev->dev, freq);
271 if (err == 0)
272 rtc->irq_freq = freq;
273 }
274 return err;
275}
276EXPORT_SYMBOL_GPL(rtc_irq_set_freq);