Commit | Line | Data |
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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 | ||
cd966209 DB |
20 | static ssize_t |
21 | rtc_sysfs_show_name(struct device *dev, struct device_attribute *attr, | |
22 | char *buf) | |
c5c3e192 AZ |
23 | { |
24 | return sprintf(buf, "%s\n", to_rtc_device(dev)->name); | |
25 | } | |
c5c3e192 | 26 | |
cd966209 DB |
27 | static ssize_t |
28 | rtc_sysfs_show_date(struct device *dev, struct device_attribute *attr, | |
29 | char *buf) | |
c5c3e192 AZ |
30 | { |
31 | ssize_t retval; | |
32 | struct rtc_time tm; | |
33 | ||
ab6a2d70 | 34 | retval = rtc_read_time(to_rtc_device(dev), &tm); |
c5c3e192 AZ |
35 | if (retval == 0) { |
36 | retval = sprintf(buf, "%04d-%02d-%02d\n", | |
37 | tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday); | |
38 | } | |
39 | ||
40 | return retval; | |
41 | } | |
c5c3e192 | 42 | |
cd966209 DB |
43 | static ssize_t |
44 | rtc_sysfs_show_time(struct device *dev, struct device_attribute *attr, | |
45 | char *buf) | |
c5c3e192 AZ |
46 | { |
47 | ssize_t retval; | |
48 | struct rtc_time tm; | |
49 | ||
ab6a2d70 | 50 | retval = rtc_read_time(to_rtc_device(dev), &tm); |
c5c3e192 AZ |
51 | if (retval == 0) { |
52 | retval = sprintf(buf, "%02d:%02d:%02d\n", | |
53 | tm.tm_hour, tm.tm_min, tm.tm_sec); | |
54 | } | |
55 | ||
56 | return retval; | |
57 | } | |
c5c3e192 | 58 | |
cd966209 DB |
59 | static ssize_t |
60 | rtc_sysfs_show_since_epoch(struct device *dev, struct device_attribute *attr, | |
61 | char *buf) | |
c5c3e192 AZ |
62 | { |
63 | ssize_t retval; | |
64 | struct rtc_time tm; | |
65 | ||
ab6a2d70 | 66 | retval = rtc_read_time(to_rtc_device(dev), &tm); |
c5c3e192 AZ |
67 | if (retval == 0) { |
68 | unsigned long time; | |
69 | rtc_tm_to_time(&tm, &time); | |
70 | retval = sprintf(buf, "%lu\n", time); | |
71 | } | |
72 | ||
73 | return retval; | |
74 | } | |
c5c3e192 | 75 | |
cd966209 | 76 | static struct device_attribute rtc_attrs[] = { |
446ecbd9 DB |
77 | __ATTR(name, S_IRUGO, rtc_sysfs_show_name, NULL), |
78 | __ATTR(date, S_IRUGO, rtc_sysfs_show_date, NULL), | |
79 | __ATTR(time, S_IRUGO, rtc_sysfs_show_time, NULL), | |
80 | __ATTR(since_epoch, S_IRUGO, rtc_sysfs_show_since_epoch, NULL), | |
81 | { }, | |
c5c3e192 AZ |
82 | }; |
83 | ||
3925a5ce | 84 | static ssize_t |
cd966209 DB |
85 | rtc_sysfs_show_wakealarm(struct device *dev, struct device_attribute *attr, |
86 | char *buf) | |
3925a5ce DB |
87 | { |
88 | ssize_t retval; | |
89 | unsigned long alarm; | |
90 | struct rtc_wkalrm alm; | |
91 | ||
92 | /* Don't show disabled alarms; but the RTC could leave the | |
93 | * alarm enabled after it's already triggered. Alarms are | |
94 | * conceptually one-shot, even though some common hardware | |
95 | * (PCs) doesn't actually work that way. | |
96 | * | |
97 | * REVISIT maybe we should require RTC implementations to | |
98 | * disable the RTC alarm after it triggers, for uniformity. | |
99 | */ | |
ab6a2d70 | 100 | retval = rtc_read_alarm(to_rtc_device(dev), &alm); |
3925a5ce DB |
101 | if (retval == 0 && alm.enabled) { |
102 | rtc_tm_to_time(&alm.time, &alarm); | |
103 | retval = sprintf(buf, "%lu\n", alarm); | |
104 | } | |
105 | ||
106 | return retval; | |
107 | } | |
108 | ||
109 | static ssize_t | |
cd966209 DB |
110 | rtc_sysfs_set_wakealarm(struct device *dev, struct device_attribute *attr, |
111 | const char *buf, size_t n) | |
3925a5ce DB |
112 | { |
113 | ssize_t retval; | |
114 | unsigned long now, alarm; | |
115 | struct rtc_wkalrm alm; | |
ab6a2d70 | 116 | struct rtc_device *rtc = to_rtc_device(dev); |
3925a5ce DB |
117 | |
118 | /* Only request alarms that trigger in the future. Disable them | |
119 | * by writing another time, e.g. 0 meaning Jan 1 1970 UTC. | |
120 | */ | |
ab6a2d70 | 121 | retval = rtc_read_time(rtc, &alm.time); |
3925a5ce DB |
122 | if (retval < 0) |
123 | return retval; | |
124 | rtc_tm_to_time(&alm.time, &now); | |
125 | ||
126 | alarm = simple_strtoul(buf, NULL, 0); | |
127 | if (alarm > now) { | |
128 | /* Avoid accidentally clobbering active alarms; we can't | |
129 | * entirely prevent that here, without even the minimal | |
130 | * locking from the /dev/rtcN api. | |
131 | */ | |
ab6a2d70 | 132 | retval = rtc_read_alarm(rtc, &alm); |
3925a5ce DB |
133 | if (retval < 0) |
134 | return retval; | |
135 | if (alm.enabled) | |
136 | return -EBUSY; | |
137 | ||
138 | alm.enabled = 1; | |
139 | } else { | |
140 | alm.enabled = 0; | |
141 | ||
142 | /* Provide a valid future alarm time. Linux isn't EFI, | |
143 | * this time won't be ignored when disabling the alarm. | |
144 | */ | |
145 | alarm = now + 300; | |
146 | } | |
147 | rtc_time_to_tm(alarm, &alm.time); | |
148 | ||
ab6a2d70 | 149 | retval = rtc_set_alarm(rtc, &alm); |
3925a5ce DB |
150 | return (retval < 0) ? retval : n; |
151 | } | |
cd966209 | 152 | static DEVICE_ATTR(wakealarm, S_IRUGO | S_IWUSR, |
3925a5ce DB |
153 | rtc_sysfs_show_wakealarm, rtc_sysfs_set_wakealarm); |
154 | ||
155 | ||
156 | /* The reason to trigger an alarm with no process watching it (via sysfs) | |
157 | * is its side effect: waking from a system state like suspend-to-RAM or | |
158 | * suspend-to-disk. So: no attribute unless that side effect is possible. | |
159 | * (Userspace may disable that mechanism later.) | |
160 | */ | |
446ecbd9 | 161 | static inline int rtc_does_wakealarm(struct rtc_device *rtc) |
3925a5ce | 162 | { |
cd966209 | 163 | if (!device_can_wakeup(rtc->dev.parent)) |
3925a5ce | 164 | return 0; |
3925a5ce DB |
165 | return rtc->ops->set_alarm != NULL; |
166 | } | |
167 | ||
168 | ||
446ecbd9 | 169 | void rtc_sysfs_add_device(struct rtc_device *rtc) |
c5c3e192 AZ |
170 | { |
171 | int err; | |
172 | ||
446ecbd9 DB |
173 | /* not all RTCs support both alarms and wakeup */ |
174 | if (!rtc_does_wakealarm(rtc)) | |
175 | return; | |
c5c3e192 | 176 | |
cd966209 | 177 | err = device_create_file(&rtc->dev, &dev_attr_wakealarm); |
c5c3e192 | 178 | if (err) |
cd966209 | 179 | dev_err(rtc->dev.parent, "failed to create " |
446ecbd9 DB |
180 | "alarm attribute, %d", |
181 | err); | |
c5c3e192 AZ |
182 | } |
183 | ||
446ecbd9 | 184 | void rtc_sysfs_del_device(struct rtc_device *rtc) |
c5c3e192 | 185 | { |
446ecbd9 DB |
186 | /* REVISIT did we add it successfully? */ |
187 | if (rtc_does_wakealarm(rtc)) | |
cd966209 | 188 | device_remove_file(&rtc->dev, &dev_attr_wakealarm); |
c5c3e192 AZ |
189 | } |
190 | ||
446ecbd9 | 191 | void __init rtc_sysfs_init(struct class *rtc_class) |
c5c3e192 | 192 | { |
cd966209 | 193 | rtc_class->dev_attrs = rtc_attrs; |
c5c3e192 | 194 | } |