[deliverable/linux.git] / drivers / rtc / rtc-sysfs.c

/*
 * RTC subsystem, sysfs interface
 *
 * Copyright (C) 2005 Tower Technologies
 * Author: Alessandro Zummo <a.zummo@towertech.it>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
*/

#include <linux/module.h>
#include <linux/rtc.h>

#include "rtc-core.h"


/* device attributes */

/*
 * NOTE:  RTC times displayed in sysfs use the RTC's timezone.  That's
 * ideally UTC.  However, PCs that also boot to MS-Windows normally use
 * the local time and change to match daylight savings time.  That affects
 * attributes including date, time, since_epoch, and wakealarm.
 */

static ssize_t
name_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	return sprintf(buf, "%s\n", to_rtc_device(dev)->name);
}
static DEVICE_ATTR_RO(name);

static ssize_t
date_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	ssize_t retval;
	struct rtc_time tm;

	retval = rtc_read_time(to_rtc_device(dev), &tm);
	if (retval == 0) {
		retval = sprintf(buf, "%04d-%02d-%02d\n",
			tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday);
	}

	return retval;
}
static DEVICE_ATTR_RO(date);

static ssize_t
time_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	ssize_t retval;
	struct rtc_time tm;

	retval = rtc_read_time(to_rtc_device(dev), &tm);
	if (retval == 0) {
		retval = sprintf(buf, "%02d:%02d:%02d\n",
			tm.tm_hour, tm.tm_min, tm.tm_sec);
	}

	return retval;
}
static DEVICE_ATTR_RO(time);

static ssize_t
since_epoch_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	ssize_t retval;
	struct rtc_time tm;

	retval = rtc_read_time(to_rtc_device(dev), &tm);
	if (retval == 0) {
		unsigned long time;
		rtc_tm_to_time(&tm, &time);
		retval = sprintf(buf, "%lu\n", time);
	}

	return retval;
}
static DEVICE_ATTR_RO(since_epoch);

static ssize_t
max_user_freq_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	return sprintf(buf, "%d\n", to_rtc_device(dev)->max_user_freq);
}

static ssize_t
max_user_freq_store(struct device *dev, struct device_attribute *attr,
		const char *buf, size_t n)
{
	struct rtc_device *rtc = to_rtc_device(dev);
	unsigned long val = simple_strtoul(buf, NULL, 0);

	if (val >= 4096 || val == 0)
		return -EINVAL;

	rtc->max_user_freq = (int)val;

	return n;
}
static DEVICE_ATTR_RW(max_user_freq);

/**
 * rtc_sysfs_show_hctosys - indicate if the given RTC set the system time
 *
 * Returns 1 if the system clock was set by this RTC at the last
 * boot or resume event.
 */
static ssize_t
hctosys_show(struct device *dev, struct device_attribute *attr, char *buf)
{
#ifdef CONFIG_RTC_HCTOSYS_DEVICE
	if (rtc_hctosys_ret == 0 &&
			strcmp(dev_name(&to_rtc_device(dev)->dev),
				CONFIG_RTC_HCTOSYS_DEVICE) == 0)
		return sprintf(buf, "1\n");
	else
#endif
		return sprintf(buf, "0\n");
}
static DEVICE_ATTR_RO(hctosys);

static ssize_t
wakealarm_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	ssize_t retval;
	unsigned long alarm;
	struct rtc_wkalrm alm;

	/* Don't show disabled alarms.  For uniformity, RTC alarms are
	 * conceptually one-shot, even though some common RTCs (on PCs)
	 * don't actually work that way.
	 *
	 * NOTE: RTC implementations where the alarm doesn't match an
	 * exact YYYY-MM-DD HH:MM[:SS] date *must* disable their RTC
	 * alarms after they trigger, to ensure one-shot semantics.
	 */
	retval = rtc_read_alarm(to_rtc_device(dev), &alm);
	if (retval == 0 && alm.enabled) {
		rtc_tm_to_time(&alm.time, &alarm);
		retval = sprintf(buf, "%lu\n", alarm);
	}

	return retval;
}

static ssize_t
wakealarm_store(struct device *dev, struct device_attribute *attr,
		const char *buf, size_t n)
{
	ssize_t retval;
	unsigned long now, alarm;
	unsigned long push = 0;
	struct rtc_wkalrm alm;
	struct rtc_device *rtc = to_rtc_device(dev);
	char *buf_ptr;
	int adjust = 0;

	/* Only request alarms that trigger in the future.  Disable them
	 * by writing another time, e.g. 0 meaning Jan 1 1970 UTC.
	 */
	retval = rtc_read_time(rtc, &alm.time);
	if (retval < 0)
		return retval;
	rtc_tm_to_time(&alm.time, &now);

	buf_ptr = (char *)buf;
	if (*buf_ptr == '+') {
		buf_ptr++;
		if (*buf_ptr == '=') {
			buf_ptr++;
			push = 1;
		} else
			adjust = 1;
	}
	alarm = simple_strtoul(buf_ptr, NULL, 0);
	if (adjust) {
		alarm += now;
	}
	if (alarm > now || push) {
		/* Avoid accidentally clobbering active alarms; we can't
		 * entirely prevent that here, without even the minimal
		 * locking from the /dev/rtcN api.
		 */
		retval = rtc_read_alarm(rtc, &alm);
		if (retval < 0)
			return retval;
		if (alm.enabled) {
			if (push) {
				rtc_tm_to_time(&alm.time, &push);
				alarm += push;
			} else
				return -EBUSY;
		} else if (push)
			return -EINVAL;
		alm.enabled = 1;
	} else {
		alm.enabled = 0;

		/* Provide a valid future alarm time.  Linux isn't EFI,
		 * this time won't be ignored when disabling the alarm.
		 */
		alarm = now + 300;
	}
	rtc_time_to_tm(alarm, &alm.time);

	retval = rtc_set_alarm(rtc, &alm);
	return (retval < 0) ? retval : n;
}
static DEVICE_ATTR_RW(wakealarm);

static struct attribute *rtc_attrs[] = {
	&dev_attr_name.attr,
	&dev_attr_date.attr,
	&dev_attr_time.attr,
	&dev_attr_since_epoch.attr,
	&dev_attr_max_user_freq.attr,
	&dev_attr_hctosys.attr,
	&dev_attr_wakealarm.attr,
	NULL,
};

/* The reason to trigger an alarm with no process watching it (via sysfs)
 * is its side effect:  waking from a system state like suspend-to-RAM or
 * suspend-to-disk.  So: no attribute unless that side effect is possible.
 * (Userspace may disable that mechanism later.)
 */
static bool rtc_does_wakealarm(struct rtc_device *rtc)
{
	if (!device_can_wakeup(rtc->dev.parent))
		return false;

	return rtc->ops->set_alarm != NULL;
}

static umode_t rtc_attr_is_visible(struct kobject *kobj,
				   struct attribute *attr, int n)
{
	struct device *dev = container_of(kobj, struct device, kobj);
	struct rtc_device *rtc = to_rtc_device(dev);
	umode_t mode = attr->mode;

	if (attr == &dev_attr_wakealarm.attr)
		if (!rtc_does_wakealarm(rtc))
			mode = 0;

	return mode;
}

static struct attribute_group rtc_attr_group = {
	.is_visible	= rtc_attr_is_visible,
	.attrs		= rtc_attrs,
};

static const struct attribute_group *rtc_attr_groups[] = {
	&rtc_attr_group,
	NULL
};

const struct attribute_group **rtc_get_dev_attribute_groups(void)
{
	return rtc_attr_groups;
}
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 */
c5c3e192 AZ	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);
	94	unsigned long val = simple_strtoul(buf, NULL, 0);
	95
	96	if (val >= 4096 \|\| val == 0)
	97	return -EINVAL;
	98
	99	rtc->max_user_freq = (int)val;
	100
	101	return n;
	102	}
f21e6835	103	static DEVICE_ATTR_RW(max_user_freq);
06c65eb4	104
4c24e29e DF	105	/**
	106	* rtc_sysfs_show_hctosys - indicate if the given RTC set the system time
	107	*
	108	* Returns 1 if the system clock was set by this RTC at the last
	109	* boot or resume event.
	110	*/
d8c1acb1	111	static ssize_t
f21e6835	112	hctosys_show(struct device dev, struct device_attribute attr, char *buf)
d8c1acb1 MG	113	{
d8c1acb1 MG	114	#ifdef CONFIG_RTC_HCTOSYS_DEVICE
d0ab4a4d UKK	115	if (rtc_hctosys_ret == 0 &&
	116	strcmp(dev_name(&to_rtc_device(dev)->dev),
	117	CONFIG_RTC_HCTOSYS_DEVICE) == 0)
d8c1acb1 MG	118	return sprintf(buf, "1\n");
	119	else
	120	#endif
	121	return sprintf(buf, "0\n");
	122	}
f21e6835 GKH	123	static DEVICE_ATTR_RO(hctosys);
f21e6835 GKH	124
3925a5ce	125	static ssize_t
a17ccd1c	126	wakealarm_show(struct device dev, struct device_attribute attr, char *buf)
3925a5ce DB	127	{
	128	ssize_t retval;
	129	unsigned long alarm;
	130	struct rtc_wkalrm alm;
	131
8a0bdfd7 DB	132	/* Don't show disabled alarms. For uniformity, RTC alarms are
	133	* conceptually one-shot, even though some common RTCs (on PCs)
	134	* don't actually work that way.
3925a5ce	135	*
8a0bdfd7 DB	136	* NOTE: RTC implementations where the alarm doesn't match an
	137	* exact YYYY-MM-DD HH:MM[:SS] date must disable their RTC
	138	* alarms after they trigger, to ensure one-shot semantics.
3925a5ce	139	*/
ab6a2d70	140	retval = rtc_read_alarm(to_rtc_device(dev), &alm);
3925a5ce DB	141	if (retval == 0 && alm.enabled) {
	142	rtc_tm_to_time(&alm.time, &alarm);
	143	retval = sprintf(buf, "%lu\n", alarm);
	144	}
	145
	146	return retval;
	147	}
	148
	149	static ssize_t
a17ccd1c	150	wakealarm_store(struct device dev, struct device_attribute attr,
cd966209	151	const char *buf, size_t n)
3925a5ce DB	152	{
	153	ssize_t retval;
	154	unsigned long now, alarm;
1df0a471	155	unsigned long push = 0;
3925a5ce	156	struct rtc_wkalrm alm;
ab6a2d70	157	struct rtc_device *rtc = to_rtc_device(dev);
c116bc2a ZY	158	char *buf_ptr;
c116bc2a ZY	159	int adjust = 0;
3925a5ce DB	160
	161	/* Only request alarms that trigger in the future. Disable them
	162	* by writing another time, e.g. 0 meaning Jan 1 1970 UTC.
	163	*/
ab6a2d70	164	retval = rtc_read_time(rtc, &alm.time);
3925a5ce DB	165	if (retval < 0)
	166	return retval;
	167	rtc_tm_to_time(&alm.time, &now);
	168
c116bc2a ZY	169	buf_ptr = (char *)buf;
	170	if (*buf_ptr == '+') {
	171	buf_ptr++;
1df0a471 BT	172	if (*buf_ptr == '=') {
	173	buf_ptr++;
	174	push = 1;
	175	} else
	176	adjust = 1;
c116bc2a ZY	177	}
	178	alarm = simple_strtoul(buf_ptr, NULL, 0);
	179	if (adjust) {
	180	alarm += now;
	181	}
1df0a471	182	if (alarm > now \|\| push) {
3925a5ce DB	183	/* Avoid accidentally clobbering active alarms; we can't
	184	* entirely prevent that here, without even the minimal
	185	* locking from the /dev/rtcN api.
	186	*/
ab6a2d70	187	retval = rtc_read_alarm(rtc, &alm);
3925a5ce DB	188	if (retval < 0)
3925a5ce DB	189	return retval;
1df0a471 BT	190	if (alm.enabled) {
	191	if (push) {
	192	rtc_tm_to_time(&alm.time, &push);
	193	alarm += push;
	194	} else
	195	return -EBUSY;
	196	} else if (push)
	197	return -EINVAL;
3925a5ce DB	198	alm.enabled = 1;
	199	} else {
	200	alm.enabled = 0;
	201
	202	/* Provide a valid future alarm time. Linux isn't EFI,
	203	* this time won't be ignored when disabling the alarm.
	204	*/
	205	alarm = now + 300;
	206	}
	207	rtc_time_to_tm(alarm, &alm.time);
	208
ab6a2d70	209	retval = rtc_set_alarm(rtc, &alm);
3925a5ce DB	210	return (retval < 0) ? retval : n;
3925a5ce DB	211	}
a17ccd1c	212	static DEVICE_ATTR_RW(wakealarm);
3925a5ce	213
3ee2c40b DT	214	static struct attribute *rtc_attrs[] = {
	215	&dev_attr_name.attr,
	216	&dev_attr_date.attr,
	217	&dev_attr_time.attr,
	218	&dev_attr_since_epoch.attr,
	219	&dev_attr_max_user_freq.attr,
	220	&dev_attr_hctosys.attr,
	221	&dev_attr_wakealarm.attr,
	222	NULL,
	223	};
3925a5ce DB	224
	225	/* The reason to trigger an alarm with no process watching it (via sysfs)
	226	* is its side effect: waking from a system state like suspend-to-RAM or
	227	* suspend-to-disk. So: no attribute unless that side effect is possible.
	228	* (Userspace may disable that mechanism later.)
	229	*/
df100c01	230	static bool rtc_does_wakealarm(struct rtc_device *rtc)
3925a5ce	231	{
cd966209	232	if (!device_can_wakeup(rtc->dev.parent))
df100c01 DT	233	return false;
df100c01 DT	234
3925a5ce DB	235	return rtc->ops->set_alarm != NULL;
	236	}
	237
3ee2c40b DT	238	static umode_t rtc_attr_is_visible(struct kobject *kobj,
3ee2c40b DT	239	struct attribute *attr, int n)
c5c3e192	240	{
3ee2c40b DT	241	struct device *dev = container_of(kobj, struct device, kobj);
	242	struct rtc_device *rtc = to_rtc_device(dev);
	243	umode_t mode = attr->mode;
c5c3e192	244
3ee2c40b DT	245	if (attr == &dev_attr_wakealarm.attr)
	246	if (!rtc_does_wakealarm(rtc))
	247	mode = 0;
c5c3e192	248
3ee2c40b	249	return mode;
c5c3e192 AZ	250	}
c5c3e192 AZ	251
3ee2c40b DT	252	static struct attribute_group rtc_attr_group = {
	253	.is_visible = rtc_attr_is_visible,
	254	.attrs = rtc_attrs,
	255	};
	256
	257	static const struct attribute_group *rtc_attr_groups[] = {
	258	&rtc_attr_group,
	259	NULL
	260	};
c5c3e192	261
3ee2c40b	262	const struct attribute_group **rtc_get_dev_attribute_groups(void)
c5c3e192	263	{
3ee2c40b	264	return rtc_attr_groups;
c5c3e192	265	}