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 | 29 | { |
77a73f3c AB |
30 | return sprintf(buf, "%s %s\n", dev_driver_string(dev->parent), |
31 | dev_name(dev->parent)); | |
c5c3e192 | 32 | } |
f21e6835 | 33 | static DEVICE_ATTR_RO(name); |
c5c3e192 | 34 | |
cd966209 | 35 | static ssize_t |
f21e6835 | 36 | date_show(struct device *dev, struct device_attribute *attr, char *buf) |
c5c3e192 AZ |
37 | { |
38 | ssize_t retval; | |
39 | struct rtc_time tm; | |
40 | ||
ab6a2d70 | 41 | retval = rtc_read_time(to_rtc_device(dev), &tm); |
c5c3e192 AZ |
42 | if (retval == 0) { |
43 | retval = sprintf(buf, "%04d-%02d-%02d\n", | |
44 | tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday); | |
45 | } | |
46 | ||
47 | return retval; | |
48 | } | |
f21e6835 | 49 | static DEVICE_ATTR_RO(date); |
c5c3e192 | 50 | |
cd966209 | 51 | static ssize_t |
f21e6835 | 52 | time_show(struct device *dev, struct device_attribute *attr, char *buf) |
c5c3e192 AZ |
53 | { |
54 | ssize_t retval; | |
55 | struct rtc_time tm; | |
56 | ||
ab6a2d70 | 57 | retval = rtc_read_time(to_rtc_device(dev), &tm); |
c5c3e192 AZ |
58 | if (retval == 0) { |
59 | retval = sprintf(buf, "%02d:%02d:%02d\n", | |
60 | tm.tm_hour, tm.tm_min, tm.tm_sec); | |
61 | } | |
62 | ||
63 | return retval; | |
64 | } | |
f21e6835 | 65 | static DEVICE_ATTR_RO(time); |
c5c3e192 | 66 | |
cd966209 | 67 | static ssize_t |
f21e6835 | 68 | since_epoch_show(struct device *dev, struct device_attribute *attr, char *buf) |
c5c3e192 AZ |
69 | { |
70 | ssize_t retval; | |
71 | struct rtc_time tm; | |
72 | ||
ab6a2d70 | 73 | retval = rtc_read_time(to_rtc_device(dev), &tm); |
c5c3e192 | 74 | if (retval == 0) { |
9a06da2e BW |
75 | time64_t time; |
76 | ||
77 | time = rtc_tm_to_time64(&tm); | |
78 | retval = sprintf(buf, "%lld\n", time); | |
c5c3e192 AZ |
79 | } |
80 | ||
81 | return retval; | |
82 | } | |
f21e6835 | 83 | static DEVICE_ATTR_RO(since_epoch); |
c5c3e192 | 84 | |
06c65eb4 | 85 | static ssize_t |
f21e6835 | 86 | max_user_freq_show(struct device *dev, struct device_attribute *attr, char *buf) |
06c65eb4 BK |
87 | { |
88 | return sprintf(buf, "%d\n", to_rtc_device(dev)->max_user_freq); | |
89 | } | |
90 | ||
91 | static ssize_t | |
f21e6835 | 92 | max_user_freq_store(struct device *dev, struct device_attribute *attr, |
06c65eb4 BK |
93 | const char *buf, size_t n) |
94 | { | |
95 | struct rtc_device *rtc = to_rtc_device(dev); | |
f571287b LC |
96 | unsigned long val; |
97 | int err; | |
98 | ||
99 | err = kstrtoul(buf, 0, &val); | |
100 | if (err) | |
101 | return err; | |
06c65eb4 BK |
102 | |
103 | if (val >= 4096 || val == 0) | |
104 | return -EINVAL; | |
105 | ||
106 | rtc->max_user_freq = (int)val; | |
107 | ||
108 | return n; | |
109 | } | |
f21e6835 | 110 | static DEVICE_ATTR_RW(max_user_freq); |
06c65eb4 | 111 | |
4c24e29e DF |
112 | /** |
113 | * rtc_sysfs_show_hctosys - indicate if the given RTC set the system time | |
114 | * | |
115 | * Returns 1 if the system clock was set by this RTC at the last | |
116 | * boot or resume event. | |
117 | */ | |
d8c1acb1 | 118 | static ssize_t |
f21e6835 | 119 | hctosys_show(struct device *dev, struct device_attribute *attr, char *buf) |
d8c1acb1 MG |
120 | { |
121 | #ifdef CONFIG_RTC_HCTOSYS_DEVICE | |
d0ab4a4d UKK |
122 | if (rtc_hctosys_ret == 0 && |
123 | strcmp(dev_name(&to_rtc_device(dev)->dev), | |
124 | CONFIG_RTC_HCTOSYS_DEVICE) == 0) | |
d8c1acb1 MG |
125 | return sprintf(buf, "1\n"); |
126 | else | |
127 | #endif | |
128 | return sprintf(buf, "0\n"); | |
129 | } | |
f21e6835 GKH |
130 | static DEVICE_ATTR_RO(hctosys); |
131 | ||
3925a5ce | 132 | static ssize_t |
a17ccd1c | 133 | wakealarm_show(struct device *dev, struct device_attribute *attr, char *buf) |
3925a5ce DB |
134 | { |
135 | ssize_t retval; | |
9a06da2e | 136 | time64_t alarm; |
3925a5ce DB |
137 | struct rtc_wkalrm alm; |
138 | ||
8a0bdfd7 DB |
139 | /* Don't show disabled alarms. For uniformity, RTC alarms are |
140 | * conceptually one-shot, even though some common RTCs (on PCs) | |
141 | * don't actually work that way. | |
3925a5ce | 142 | * |
8a0bdfd7 DB |
143 | * NOTE: RTC implementations where the alarm doesn't match an |
144 | * exact YYYY-MM-DD HH:MM[:SS] date *must* disable their RTC | |
145 | * alarms after they trigger, to ensure one-shot semantics. | |
3925a5ce | 146 | */ |
ab6a2d70 | 147 | retval = rtc_read_alarm(to_rtc_device(dev), &alm); |
3925a5ce | 148 | if (retval == 0 && alm.enabled) { |
9a06da2e BW |
149 | alarm = rtc_tm_to_time64(&alm.time); |
150 | retval = sprintf(buf, "%lld\n", alarm); | |
3925a5ce DB |
151 | } |
152 | ||
153 | return retval; | |
154 | } | |
155 | ||
156 | static ssize_t | |
a17ccd1c | 157 | wakealarm_store(struct device *dev, struct device_attribute *attr, |
cd966209 | 158 | const char *buf, size_t n) |
3925a5ce DB |
159 | { |
160 | ssize_t retval; | |
9a06da2e BW |
161 | time64_t now, alarm; |
162 | time64_t push = 0; | |
3925a5ce | 163 | struct rtc_wkalrm alm; |
ab6a2d70 | 164 | struct rtc_device *rtc = to_rtc_device(dev); |
84281c2d | 165 | const char *buf_ptr; |
c116bc2a | 166 | int adjust = 0; |
3925a5ce DB |
167 | |
168 | /* Only request alarms that trigger in the future. Disable them | |
169 | * by writing another time, e.g. 0 meaning Jan 1 1970 UTC. | |
170 | */ | |
ab6a2d70 | 171 | retval = rtc_read_time(rtc, &alm.time); |
3925a5ce DB |
172 | if (retval < 0) |
173 | return retval; | |
9a06da2e | 174 | now = rtc_tm_to_time64(&alm.time); |
3925a5ce | 175 | |
84281c2d | 176 | buf_ptr = buf; |
c116bc2a ZY |
177 | if (*buf_ptr == '+') { |
178 | buf_ptr++; | |
1df0a471 BT |
179 | if (*buf_ptr == '=') { |
180 | buf_ptr++; | |
181 | push = 1; | |
182 | } else | |
183 | adjust = 1; | |
c116bc2a | 184 | } |
9a06da2e | 185 | retval = kstrtos64(buf_ptr, 0, &alarm); |
f571287b LC |
186 | if (retval) |
187 | return retval; | |
c116bc2a ZY |
188 | if (adjust) { |
189 | alarm += now; | |
190 | } | |
1df0a471 | 191 | if (alarm > now || push) { |
3925a5ce DB |
192 | /* Avoid accidentally clobbering active alarms; we can't |
193 | * entirely prevent that here, without even the minimal | |
194 | * locking from the /dev/rtcN api. | |
195 | */ | |
ab6a2d70 | 196 | retval = rtc_read_alarm(rtc, &alm); |
3925a5ce DB |
197 | if (retval < 0) |
198 | return retval; | |
1df0a471 BT |
199 | if (alm.enabled) { |
200 | if (push) { | |
9a06da2e | 201 | push = rtc_tm_to_time64(&alm.time); |
1df0a471 BT |
202 | alarm += push; |
203 | } else | |
204 | return -EBUSY; | |
205 | } else if (push) | |
206 | return -EINVAL; | |
3925a5ce DB |
207 | alm.enabled = 1; |
208 | } else { | |
209 | alm.enabled = 0; | |
210 | ||
211 | /* Provide a valid future alarm time. Linux isn't EFI, | |
212 | * this time won't be ignored when disabling the alarm. | |
213 | */ | |
214 | alarm = now + 300; | |
215 | } | |
9a06da2e | 216 | rtc_time64_to_tm(alarm, &alm.time); |
3925a5ce | 217 | |
ab6a2d70 | 218 | retval = rtc_set_alarm(rtc, &alm); |
3925a5ce DB |
219 | return (retval < 0) ? retval : n; |
220 | } | |
a17ccd1c | 221 | static DEVICE_ATTR_RW(wakealarm); |
3925a5ce | 222 | |
5495a415 JC |
223 | static ssize_t |
224 | offset_show(struct device *dev, struct device_attribute *attr, char *buf) | |
225 | { | |
226 | ssize_t retval; | |
227 | long offset; | |
228 | ||
229 | retval = rtc_read_offset(to_rtc_device(dev), &offset); | |
230 | if (retval == 0) | |
231 | retval = sprintf(buf, "%ld\n", offset); | |
232 | ||
233 | return retval; | |
234 | } | |
235 | ||
236 | static ssize_t | |
237 | offset_store(struct device *dev, struct device_attribute *attr, | |
238 | const char *buf, size_t n) | |
239 | { | |
240 | ssize_t retval; | |
241 | long offset; | |
242 | ||
243 | retval = kstrtol(buf, 10, &offset); | |
244 | if (retval == 0) | |
245 | retval = rtc_set_offset(to_rtc_device(dev), offset); | |
246 | ||
247 | return (retval < 0) ? retval : n; | |
248 | } | |
249 | static DEVICE_ATTR_RW(offset); | |
250 | ||
71db049e AB |
251 | static ssize_t |
252 | range_show(struct device *dev, struct device_attribute *attr, char *buf) | |
253 | { | |
254 | return sprintf(buf, "[%lld,%llu]\n", to_rtc_device(dev)->range_min, | |
255 | to_rtc_device(dev)->range_max); | |
256 | } | |
257 | static DEVICE_ATTR_RO(range); | |
258 | ||
3ee2c40b DT |
259 | static struct attribute *rtc_attrs[] = { |
260 | &dev_attr_name.attr, | |
261 | &dev_attr_date.attr, | |
262 | &dev_attr_time.attr, | |
263 | &dev_attr_since_epoch.attr, | |
264 | &dev_attr_max_user_freq.attr, | |
265 | &dev_attr_hctosys.attr, | |
266 | &dev_attr_wakealarm.attr, | |
5495a415 | 267 | &dev_attr_offset.attr, |
71db049e | 268 | &dev_attr_range.attr, |
3ee2c40b DT |
269 | NULL, |
270 | }; | |
3925a5ce DB |
271 | |
272 | /* The reason to trigger an alarm with no process watching it (via sysfs) | |
273 | * is its side effect: waking from a system state like suspend-to-RAM or | |
274 | * suspend-to-disk. So: no attribute unless that side effect is possible. | |
275 | * (Userspace may disable that mechanism later.) | |
276 | */ | |
df100c01 | 277 | static bool rtc_does_wakealarm(struct rtc_device *rtc) |
3925a5ce | 278 | { |
cd966209 | 279 | if (!device_can_wakeup(rtc->dev.parent)) |
df100c01 DT |
280 | return false; |
281 | ||
3925a5ce DB |
282 | return rtc->ops->set_alarm != NULL; |
283 | } | |
284 | ||
3ee2c40b DT |
285 | static umode_t rtc_attr_is_visible(struct kobject *kobj, |
286 | struct attribute *attr, int n) | |
c5c3e192 | 287 | { |
3ee2c40b DT |
288 | struct device *dev = container_of(kobj, struct device, kobj); |
289 | struct rtc_device *rtc = to_rtc_device(dev); | |
290 | umode_t mode = attr->mode; | |
c5c3e192 | 291 | |
5495a415 | 292 | if (attr == &dev_attr_wakealarm.attr) { |
3ee2c40b DT |
293 | if (!rtc_does_wakealarm(rtc)) |
294 | mode = 0; | |
5495a415 JC |
295 | } else if (attr == &dev_attr_offset.attr) { |
296 | if (!rtc->ops->set_offset) | |
297 | mode = 0; | |
71db049e AB |
298 | } else if (attr == &dev_attr_range.attr) { |
299 | if (!(rtc->range_max - rtc->range_min)) | |
300 | mode = 0; | |
5495a415 | 301 | } |
c5c3e192 | 302 | |
3ee2c40b | 303 | return mode; |
c5c3e192 AZ |
304 | } |
305 | ||
3ee2c40b DT |
306 | static struct attribute_group rtc_attr_group = { |
307 | .is_visible = rtc_attr_is_visible, | |
308 | .attrs = rtc_attrs, | |
309 | }; | |
310 | ||
311 | static const struct attribute_group *rtc_attr_groups[] = { | |
312 | &rtc_attr_group, | |
313 | NULL | |
314 | }; | |
c5c3e192 | 315 | |
3ee2c40b | 316 | const struct attribute_group **rtc_get_dev_attribute_groups(void) |
c5c3e192 | 317 | { |
3ee2c40b | 318 | return rtc_attr_groups; |
c5c3e192 | 319 | } |