[linux-2.6-block.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;
	int err;

	err = kstrtoul(buf, 0, &val);
	if (err)
		return err;

	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;
	}
	retval = kstrtoul(buf_ptr, 0, &alarm);
	if (retval)
		return retval;
	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 ssize_t
offset_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	ssize_t retval;
	long offset;

	retval = rtc_read_offset(to_rtc_device(dev), &offset);
	if (retval == 0)
		retval = sprintf(buf, "%ld\n", offset);

	return retval;
}

static ssize_t
offset_store(struct device *dev, struct device_attribute *attr,
	     const char *buf, size_t n)
{
	ssize_t retval;
	long offset;

	retval = kstrtol(buf, 10, &offset);
	if (retval == 0)
		retval = rtc_set_offset(to_rtc_device(dev), offset);

	return (retval < 0) ? retval : n;
}
static DEVICE_ATTR_RW(offset);

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,
	&dev_attr_offset.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;
	} else if (attr == &dev_attr_offset.attr) {
		if (!rtc->ops->set_offset)
			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);
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	{
d8c1acb1 MG	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);
f21e6835 GKH	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;
c116bc2a ZY	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)
3925a5ce DB	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;
3925a5ce DB	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,
3ee2c40b DT	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;
df100c01 DT	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,
3ee2c40b DT	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))
3ee2c40b DT	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	}
c5c3e192 AZ	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	}