Commit | Line | Data |
---|---|---|
c5c3e192 AZ |
1 | /* |
2 | * RTC subsystem, sysfs interface | |
3 | * | |
4 | * Copyright (C) 2005 Tower Technologies | |
5 | * Author: Alessandro Zummo <a.zummo@towertech.it> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | */ | |
11 | ||
12 | #include <linux/module.h> | |
13 | #include <linux/rtc.h> | |
14 | ||
ab6a2d70 DB |
15 | #include "rtc-core.h" |
16 | ||
17 | ||
c5c3e192 AZ |
18 | /* device attributes */ |
19 | ||
8a0bdfd7 DB |
20 | /* |
21 | * NOTE: RTC times displayed in sysfs use the RTC's timezone. That's | |
22 | * ideally UTC. However, PCs that also boot to MS-Windows normally use | |
23 | * the local time and change to match daylight savings time. That affects | |
24 | * attributes including date, time, since_epoch, and wakealarm. | |
25 | */ | |
26 | ||
cd966209 | 27 | static ssize_t |
f21e6835 | 28 | name_show(struct device *dev, struct device_attribute *attr, char *buf) |
c5c3e192 AZ |
29 | { |
30 | return sprintf(buf, "%s\n", to_rtc_device(dev)->name); | |
31 | } | |
f21e6835 | 32 | static DEVICE_ATTR_RO(name); |
c5c3e192 | 33 | |
cd966209 | 34 | static ssize_t |
f21e6835 | 35 | date_show(struct device *dev, struct device_attribute *attr, char *buf) |
c5c3e192 AZ |
36 | { |
37 | ssize_t retval; | |
38 | struct rtc_time tm; | |
39 | ||
ab6a2d70 | 40 | retval = rtc_read_time(to_rtc_device(dev), &tm); |
c5c3e192 AZ |
41 | if (retval == 0) { |
42 | retval = sprintf(buf, "%04d-%02d-%02d\n", | |
43 | tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday); | |
44 | } | |
45 | ||
46 | return retval; | |
47 | } | |
f21e6835 | 48 | static DEVICE_ATTR_RO(date); |
c5c3e192 | 49 | |
cd966209 | 50 | static ssize_t |
f21e6835 | 51 | time_show(struct device *dev, struct device_attribute *attr, char *buf) |
c5c3e192 AZ |
52 | { |
53 | ssize_t retval; | |
54 | struct rtc_time tm; | |
55 | ||
ab6a2d70 | 56 | retval = rtc_read_time(to_rtc_device(dev), &tm); |
c5c3e192 AZ |
57 | if (retval == 0) { |
58 | retval = sprintf(buf, "%02d:%02d:%02d\n", | |
59 | tm.tm_hour, tm.tm_min, tm.tm_sec); | |
60 | } | |
61 | ||
62 | return retval; | |
63 | } | |
f21e6835 | 64 | static DEVICE_ATTR_RO(time); |
c5c3e192 | 65 | |
cd966209 | 66 | static ssize_t |
f21e6835 | 67 | since_epoch_show(struct device *dev, struct device_attribute *attr, char *buf) |
c5c3e192 AZ |
68 | { |
69 | ssize_t retval; | |
70 | struct rtc_time tm; | |
71 | ||
ab6a2d70 | 72 | retval = rtc_read_time(to_rtc_device(dev), &tm); |
c5c3e192 AZ |
73 | if (retval == 0) { |
74 | unsigned long time; | |
75 | rtc_tm_to_time(&tm, &time); | |
76 | retval = sprintf(buf, "%lu\n", time); | |
77 | } | |
78 | ||
79 | return retval; | |
80 | } | |
f21e6835 | 81 | static DEVICE_ATTR_RO(since_epoch); |
c5c3e192 | 82 | |
06c65eb4 | 83 | static ssize_t |
f21e6835 | 84 | max_user_freq_show(struct device *dev, struct device_attribute *attr, char *buf) |
06c65eb4 BK |
85 | { |
86 | return sprintf(buf, "%d\n", to_rtc_device(dev)->max_user_freq); | |
87 | } | |
88 | ||
89 | static ssize_t | |
f21e6835 | 90 | max_user_freq_store(struct device *dev, struct device_attribute *attr, |
06c65eb4 BK |
91 | const char *buf, size_t n) |
92 | { | |
93 | struct rtc_device *rtc = to_rtc_device(dev); | |
f571287b LC |
94 | unsigned long val; |
95 | int err; | |
96 | ||
97 | err = kstrtoul(buf, 0, &val); | |
98 | if (err) | |
99 | return err; | |
06c65eb4 BK |
100 | |
101 | if (val >= 4096 || val == 0) | |
102 | return -EINVAL; | |
103 | ||
104 | rtc->max_user_freq = (int)val; | |
105 | ||
106 | return n; | |
107 | } | |
f21e6835 | 108 | static DEVICE_ATTR_RW(max_user_freq); |
06c65eb4 | 109 | |
4c24e29e DF |
110 | /** |
111 | * rtc_sysfs_show_hctosys - indicate if the given RTC set the system time | |
112 | * | |
113 | * Returns 1 if the system clock was set by this RTC at the last | |
114 | * boot or resume event. | |
115 | */ | |
d8c1acb1 | 116 | static ssize_t |
f21e6835 | 117 | hctosys_show(struct device *dev, struct device_attribute *attr, char *buf) |
d8c1acb1 MG |
118 | { |
119 | #ifdef CONFIG_RTC_HCTOSYS_DEVICE | |
d0ab4a4d UKK |
120 | if (rtc_hctosys_ret == 0 && |
121 | strcmp(dev_name(&to_rtc_device(dev)->dev), | |
122 | CONFIG_RTC_HCTOSYS_DEVICE) == 0) | |
d8c1acb1 MG |
123 | return sprintf(buf, "1\n"); |
124 | else | |
125 | #endif | |
126 | return sprintf(buf, "0\n"); | |
127 | } | |
f21e6835 GKH |
128 | static DEVICE_ATTR_RO(hctosys); |
129 | ||
3925a5ce | 130 | static ssize_t |
a17ccd1c | 131 | wakealarm_show(struct device *dev, struct device_attribute *attr, char *buf) |
3925a5ce DB |
132 | { |
133 | ssize_t retval; | |
134 | unsigned long alarm; | |
135 | struct rtc_wkalrm alm; | |
136 | ||
8a0bdfd7 DB |
137 | /* Don't show disabled alarms. For uniformity, RTC alarms are |
138 | * conceptually one-shot, even though some common RTCs (on PCs) | |
139 | * don't actually work that way. | |
3925a5ce | 140 | * |
8a0bdfd7 DB |
141 | * NOTE: RTC implementations where the alarm doesn't match an |
142 | * exact YYYY-MM-DD HH:MM[:SS] date *must* disable their RTC | |
143 | * alarms after they trigger, to ensure one-shot semantics. | |
3925a5ce | 144 | */ |
ab6a2d70 | 145 | retval = rtc_read_alarm(to_rtc_device(dev), &alm); |
3925a5ce DB |
146 | if (retval == 0 && alm.enabled) { |
147 | rtc_tm_to_time(&alm.time, &alarm); | |
148 | retval = sprintf(buf, "%lu\n", alarm); | |
149 | } | |
150 | ||
151 | return retval; | |
152 | } | |
153 | ||
154 | static ssize_t | |
a17ccd1c | 155 | wakealarm_store(struct device *dev, struct device_attribute *attr, |
cd966209 | 156 | const char *buf, size_t n) |
3925a5ce DB |
157 | { |
158 | ssize_t retval; | |
159 | unsigned long now, alarm; | |
1df0a471 | 160 | unsigned long push = 0; |
3925a5ce | 161 | struct rtc_wkalrm alm; |
ab6a2d70 | 162 | struct rtc_device *rtc = to_rtc_device(dev); |
c116bc2a ZY |
163 | char *buf_ptr; |
164 | int adjust = 0; | |
3925a5ce DB |
165 | |
166 | /* Only request alarms that trigger in the future. Disable them | |
167 | * by writing another time, e.g. 0 meaning Jan 1 1970 UTC. | |
168 | */ | |
ab6a2d70 | 169 | retval = rtc_read_time(rtc, &alm.time); |
3925a5ce DB |
170 | if (retval < 0) |
171 | return retval; | |
172 | rtc_tm_to_time(&alm.time, &now); | |
173 | ||
c116bc2a ZY |
174 | buf_ptr = (char *)buf; |
175 | if (*buf_ptr == '+') { | |
176 | buf_ptr++; | |
1df0a471 BT |
177 | if (*buf_ptr == '=') { |
178 | buf_ptr++; | |
179 | push = 1; | |
180 | } else | |
181 | adjust = 1; | |
c116bc2a | 182 | } |
f571287b LC |
183 | retval = kstrtoul(buf_ptr, 0, &alarm); |
184 | if (retval) | |
185 | return retval; | |
c116bc2a ZY |
186 | if (adjust) { |
187 | alarm += now; | |
188 | } | |
1df0a471 | 189 | if (alarm > now || push) { |
3925a5ce DB |
190 | /* Avoid accidentally clobbering active alarms; we can't |
191 | * entirely prevent that here, without even the minimal | |
192 | * locking from the /dev/rtcN api. | |
193 | */ | |
ab6a2d70 | 194 | retval = rtc_read_alarm(rtc, &alm); |
3925a5ce DB |
195 | if (retval < 0) |
196 | return retval; | |
1df0a471 BT |
197 | if (alm.enabled) { |
198 | if (push) { | |
199 | rtc_tm_to_time(&alm.time, &push); | |
200 | alarm += push; | |
201 | } else | |
202 | return -EBUSY; | |
203 | } else if (push) | |
204 | return -EINVAL; | |
3925a5ce DB |
205 | alm.enabled = 1; |
206 | } else { | |
207 | alm.enabled = 0; | |
208 | ||
209 | /* Provide a valid future alarm time. Linux isn't EFI, | |
210 | * this time won't be ignored when disabling the alarm. | |
211 | */ | |
212 | alarm = now + 300; | |
213 | } | |
214 | rtc_time_to_tm(alarm, &alm.time); | |
215 | ||
ab6a2d70 | 216 | retval = rtc_set_alarm(rtc, &alm); |
3925a5ce DB |
217 | return (retval < 0) ? retval : n; |
218 | } | |
a17ccd1c | 219 | static DEVICE_ATTR_RW(wakealarm); |
3925a5ce | 220 | |
5495a415 JC |
221 | static ssize_t |
222 | offset_show(struct device *dev, struct device_attribute *attr, char *buf) | |
223 | { | |
224 | ssize_t retval; | |
225 | long offset; | |
226 | ||
227 | retval = rtc_read_offset(to_rtc_device(dev), &offset); | |
228 | if (retval == 0) | |
229 | retval = sprintf(buf, "%ld\n", offset); | |
230 | ||
231 | return retval; | |
232 | } | |
233 | ||
234 | static ssize_t | |
235 | offset_store(struct device *dev, struct device_attribute *attr, | |
236 | const char *buf, size_t n) | |
237 | { | |
238 | ssize_t retval; | |
239 | long offset; | |
240 | ||
241 | retval = kstrtol(buf, 10, &offset); | |
242 | if (retval == 0) | |
243 | retval = rtc_set_offset(to_rtc_device(dev), offset); | |
244 | ||
245 | return (retval < 0) ? retval : n; | |
246 | } | |
247 | static DEVICE_ATTR_RW(offset); | |
248 | ||
3ee2c40b DT |
249 | static struct attribute *rtc_attrs[] = { |
250 | &dev_attr_name.attr, | |
251 | &dev_attr_date.attr, | |
252 | &dev_attr_time.attr, | |
253 | &dev_attr_since_epoch.attr, | |
254 | &dev_attr_max_user_freq.attr, | |
255 | &dev_attr_hctosys.attr, | |
256 | &dev_attr_wakealarm.attr, | |
5495a415 | 257 | &dev_attr_offset.attr, |
3ee2c40b DT |
258 | NULL, |
259 | }; | |
3925a5ce DB |
260 | |
261 | /* The reason to trigger an alarm with no process watching it (via sysfs) | |
262 | * is its side effect: waking from a system state like suspend-to-RAM or | |
263 | * suspend-to-disk. So: no attribute unless that side effect is possible. | |
264 | * (Userspace may disable that mechanism later.) | |
265 | */ | |
df100c01 | 266 | static bool rtc_does_wakealarm(struct rtc_device *rtc) |
3925a5ce | 267 | { |
cd966209 | 268 | if (!device_can_wakeup(rtc->dev.parent)) |
df100c01 DT |
269 | return false; |
270 | ||
3925a5ce DB |
271 | return rtc->ops->set_alarm != NULL; |
272 | } | |
273 | ||
3ee2c40b DT |
274 | static umode_t rtc_attr_is_visible(struct kobject *kobj, |
275 | struct attribute *attr, int n) | |
c5c3e192 | 276 | { |
3ee2c40b DT |
277 | struct device *dev = container_of(kobj, struct device, kobj); |
278 | struct rtc_device *rtc = to_rtc_device(dev); | |
279 | umode_t mode = attr->mode; | |
c5c3e192 | 280 | |
5495a415 | 281 | if (attr == &dev_attr_wakealarm.attr) { |
3ee2c40b DT |
282 | if (!rtc_does_wakealarm(rtc)) |
283 | mode = 0; | |
5495a415 JC |
284 | } else if (attr == &dev_attr_offset.attr) { |
285 | if (!rtc->ops->set_offset) | |
286 | mode = 0; | |
287 | } | |
c5c3e192 | 288 | |
3ee2c40b | 289 | return mode; |
c5c3e192 AZ |
290 | } |
291 | ||
3ee2c40b DT |
292 | static struct attribute_group rtc_attr_group = { |
293 | .is_visible = rtc_attr_is_visible, | |
294 | .attrs = rtc_attrs, | |
295 | }; | |
296 | ||
297 | static const struct attribute_group *rtc_attr_groups[] = { | |
298 | &rtc_attr_group, | |
299 | NULL | |
300 | }; | |
c5c3e192 | 301 | |
3ee2c40b | 302 | const struct attribute_group **rtc_get_dev_attribute_groups(void) |
c5c3e192 | 303 | { |
3ee2c40b | 304 | return rtc_attr_groups; |
c5c3e192 | 305 | } |