[linux-2.6-block.git] / drivers / rtc / rtc-efi.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * rtc-efi: RTC Class Driver for EFI-based systems
 *
 * Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
 *
 * Author: dann frazier <dannf@dannf.org>
 * Based on efirtc.c by Stephane Eranian
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/stringify.h>
#include <linux/time.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
#include <linux/efi.h>

#define EFI_ISDST (EFI_TIME_ADJUST_DAYLIGHT|EFI_TIME_IN_DAYLIGHT)

/*
 * returns day of the year [0-365]
 */
static inline int
compute_yday(efi_time_t *eft)
{
	/* efi_time_t.month is in the [1-12] so, we need -1 */
	return rtc_year_days(eft->day, eft->month - 1, eft->year);
}

/*
 * returns day of the week [0-6] 0=Sunday
 */
static int
compute_wday(efi_time_t *eft, int yday)
{
	int ndays = eft->year * (365 % 7)
		    + (eft->year - 1) / 4
		    - (eft->year - 1) / 100
		    + (eft->year - 1) / 400
		    + yday;

	/*
	 * 1/1/0000 may or may not have been a Sunday (if it ever existed at
	 * all) but assuming it was makes this calculation work correctly.
	 */
	return ndays % 7;
}

static void
convert_to_efi_time(struct rtc_time *wtime, efi_time_t *eft)
{
	eft->year	= wtime->tm_year + 1900;
	eft->month	= wtime->tm_mon + 1;
	eft->day	= wtime->tm_mday;
	eft->hour	= wtime->tm_hour;
	eft->minute	= wtime->tm_min;
	eft->second	= wtime->tm_sec;
	eft->nanosecond = 0;
	eft->daylight	= wtime->tm_isdst ? EFI_ISDST : 0;
	eft->timezone	= EFI_UNSPECIFIED_TIMEZONE;
}

static bool
convert_from_efi_time(efi_time_t *eft, struct rtc_time *wtime)
{
	memset(wtime, 0, sizeof(*wtime));

	if (eft->second >= 60)
		return false;
	wtime->tm_sec  = eft->second;

	if (eft->minute >= 60)
		return false;
	wtime->tm_min  = eft->minute;

	if (eft->hour >= 24)
		return false;
	wtime->tm_hour = eft->hour;

	if (!eft->day || eft->day > 31)
		return false;
	wtime->tm_mday = eft->day;

	if (!eft->month || eft->month > 12)
		return false;
	wtime->tm_mon  = eft->month - 1;

	if (eft->year < 1900 || eft->year > 9999)
		return false;
	wtime->tm_year = eft->year - 1900;

	/* day in the year [1-365]*/
	wtime->tm_yday = compute_yday(eft);

	/* day of the week [0-6], Sunday=0 */
	wtime->tm_wday = compute_wday(eft, wtime->tm_yday);

	switch (eft->daylight & EFI_ISDST) {
	case EFI_ISDST:
		wtime->tm_isdst = 1;
		break;
	case EFI_TIME_ADJUST_DAYLIGHT:
		wtime->tm_isdst = 0;
		break;
	default:
		wtime->tm_isdst = -1;
	}

	return true;
}

static int efi_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
{
	efi_time_t eft;
	efi_status_t status;

	/*
	 * As of EFI v1.10, this call always returns an unsupported status
	 */
	status = efi.get_wakeup_time((efi_bool_t *)&wkalrm->enabled,
				     (efi_bool_t *)&wkalrm->pending, &eft);

	if (status != EFI_SUCCESS)
		return -EINVAL;

	if (!convert_from_efi_time(&eft, &wkalrm->time))
		return -EIO;

	return rtc_valid_tm(&wkalrm->time);
}

static int efi_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
{
	efi_time_t eft;
	efi_status_t status;

	convert_to_efi_time(&wkalrm->time, &eft);

	/*
	 * XXX Fixme:
	 * As of EFI 0.92 with the firmware I have on my
	 * machine this call does not seem to work quite
	 * right
	 *
	 * As of v1.10, this call always returns an unsupported status
	 */
	status = efi.set_wakeup_time((efi_bool_t)wkalrm->enabled, &eft);

	dev_warn(dev, "write status is %d\n", (int)status);

	return status == EFI_SUCCESS ? 0 : -EINVAL;
}

static int efi_read_time(struct device *dev, struct rtc_time *tm)
{
	efi_status_t status;
	efi_time_t eft;
	efi_time_cap_t cap;

	status = efi.get_time(&eft, &cap);

	if (status != EFI_SUCCESS) {
		/* should never happen */
		dev_err(dev, "can't read time\n");
		return -EINVAL;
	}

	if (!convert_from_efi_time(&eft, tm))
		return -EIO;

	return 0;
}

static int efi_set_time(struct device *dev, struct rtc_time *tm)
{
	efi_status_t status;
	efi_time_t eft;

	convert_to_efi_time(tm, &eft);

	status = efi.set_time(&eft);

	return status == EFI_SUCCESS ? 0 : -EINVAL;
}

static int efi_procfs(struct device *dev, struct seq_file *seq)
{
	efi_time_t      eft, alm;
	efi_time_cap_t  cap;
	efi_bool_t      enabled, pending;

	memset(&eft, 0, sizeof(eft));
	memset(&alm, 0, sizeof(alm));
	memset(&cap, 0, sizeof(cap));

	efi.get_time(&eft, &cap);
	efi.get_wakeup_time(&enabled, &pending, &alm);

	seq_printf(seq,
		   "Time\t\t: %u:%u:%u.%09u\n"
		   "Date\t\t: %u-%u-%u\n"
		   "Daylight\t: %u\n",
		   eft.hour, eft.minute, eft.second, eft.nanosecond,
		   eft.year, eft.month, eft.day,
		   eft.daylight);

	if (eft.timezone == EFI_UNSPECIFIED_TIMEZONE)
		seq_puts(seq, "Timezone\t: unspecified\n");
	else
		/* XXX fixme: convert to string? */
		seq_printf(seq, "Timezone\t: %u\n", eft.timezone);

	seq_printf(seq,
		   "Alarm Time\t: %u:%u:%u.%09u\n"
		   "Alarm Date\t: %u-%u-%u\n"
		   "Alarm Daylight\t: %u\n"
		   "Enabled\t\t: %s\n"
		   "Pending\t\t: %s\n",
		   alm.hour, alm.minute, alm.second, alm.nanosecond,
		   alm.year, alm.month, alm.day,
		   alm.daylight,
		   enabled == 1 ? "yes" : "no",
		   pending == 1 ? "yes" : "no");

	if (eft.timezone == EFI_UNSPECIFIED_TIMEZONE)
		seq_puts(seq, "Timezone\t: unspecified\n");
	else
		/* XXX fixme: convert to string? */
		seq_printf(seq, "Timezone\t: %u\n", alm.timezone);

	/*
	 * now prints the capabilities
	 */
	seq_printf(seq,
		   "Resolution\t: %u\n"
		   "Accuracy\t: %u\n"
		   "SetstoZero\t: %u\n",
		   cap.resolution, cap.accuracy, cap.sets_to_zero);

	return 0;
}

static const struct rtc_class_ops efi_rtc_ops = {
	.read_time	= efi_read_time,
	.set_time	= efi_set_time,
	.read_alarm	= efi_read_alarm,
	.set_alarm	= efi_set_alarm,
	.proc		= efi_procfs,
};

static int __init efi_rtc_probe(struct platform_device *dev)
{
	struct rtc_device *rtc;
	efi_time_t eft;
	efi_time_cap_t cap;

	/* First check if the RTC is usable */
	if (efi.get_time(&eft, &cap) != EFI_SUCCESS)
		return -ENODEV;

	rtc = devm_rtc_allocate_device(&dev->dev);
	if (IS_ERR(rtc))
		return PTR_ERR(rtc);

	platform_set_drvdata(dev, rtc);

	rtc->ops = &efi_rtc_ops;
	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features);
	set_bit(RTC_FEATURE_ALARM_WAKEUP_ONLY, rtc->features);

	return devm_rtc_register_device(rtc);
}

static struct platform_driver efi_rtc_driver = {
	.driver = {
		.name = "rtc-efi",
	},
};

module_platform_driver_probe(efi_rtc_driver, efi_rtc_probe);

MODULE_AUTHOR("dann frazier <dannf@dannf.org>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("EFI RTC driver");
MODULE_ALIAS("platform:rtc-efi");
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
5e3fd9e5	2	/*
	3	* rtc-efi: RTC Class Driver for EFI-based systems
	4	*
	5	* Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
	6	*
37563e5e	7	* Author: dann frazier <dannf@dannf.org>
5e3fd9e5	8	* Based on efirtc.c by Stephane Eranian
5e3fd9e5	9	*/
5e3fd9e5	10
34650f9e JH	11	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
34650f9e JH	12
5e3fd9e5	13	#include <linux/kernel.h>
5e3fd9e5	14	#include <linux/module.h>
6e85bab6	15	#include <linux/stringify.h>
5e3fd9e5	16	#include <linux/time.h>
	17	#include <linux/platform_device.h>
	18	#include <linux/rtc.h>
	19	#include <linux/efi.h>
	20
	21	#define EFI_ISDST (EFI_TIME_ADJUST_DAYLIGHT\|EFI_TIME_IN_DAYLIGHT)
5e3fd9e5	22
	23	/*
	24	* returns day of the year [0-365]
	25	*/
	26	static inline int
	27	compute_yday(efi_time_t *eft)
	28	{
	29	/* efi_time_t.month is in the [1-12] so, we need -1 */
809d9627	30	return rtc_year_days(eft->day, eft->month - 1, eft->year);
5e3fd9e5	31	}
b2bd2370	32
5e3fd9e5	33	/*
5e3fd9e5	34	* returns day of the week [0-6] 0=Sunday
5e3fd9e5	35	*/
5e3fd9e5	36	static int
b2bd2370	37	compute_wday(efi_time_t *eft, int yday)
5e3fd9e5	38	{
b2bd2370 AB	39	int ndays = eft->year * (365 % 7)
	40	+ (eft->year - 1) / 4
	41	- (eft->year - 1) / 100
	42	+ (eft->year - 1) / 400
	43	+ yday;
5e3fd9e5	44
5e3fd9e5	45	/*
b2bd2370 AB	46	* 1/1/0000 may or may not have been a Sunday (if it ever existed at
b2bd2370 AB	47	* all) but assuming it was makes this calculation work correctly.
5e3fd9e5	48	*/
b2bd2370	49	return ndays % 7;
5e3fd9e5	50	}
	51
	52	static void
	53	convert_to_efi_time(struct rtc_time wtime, efi_time_t eft)
	54	{
	55	eft->year = wtime->tm_year + 1900;
	56	eft->month = wtime->tm_mon + 1;
	57	eft->day = wtime->tm_mday;
	58	eft->hour = wtime->tm_hour;
	59	eft->minute = wtime->tm_min;
34650f9e	60	eft->second = wtime->tm_sec;
5e3fd9e5	61	eft->nanosecond = 0;
	62	eft->daylight = wtime->tm_isdst ? EFI_ISDST : 0;
	63	eft->timezone = EFI_UNSPECIFIED_TIMEZONE;
	64	}
	65
6e85bab6	66	static bool
5e3fd9e5	67	convert_from_efi_time(efi_time_t eft, struct rtc_time wtime)
	68	{
	69	memset(wtime, 0, sizeof(*wtime));
6e85bab6 JB	70
	71	if (eft->second >= 60)
	72	return false;
5e3fd9e5	73	wtime->tm_sec = eft->second;
6e85bab6 JB	74
	75	if (eft->minute >= 60)
	76	return false;
5e3fd9e5	77	wtime->tm_min = eft->minute;
6e85bab6 JB	78
	79	if (eft->hour >= 24)
	80	return false;
5e3fd9e5	81	wtime->tm_hour = eft->hour;
6e85bab6 JB	82
	83	if (!eft->day \|\| eft->day > 31)
	84	return false;
5e3fd9e5	85	wtime->tm_mday = eft->day;
6e85bab6 JB	86
	87	if (!eft->month \|\| eft->month > 12)
	88	return false;
5e3fd9e5	89	wtime->tm_mon = eft->month - 1;
5e3fd9e5	90
b2bd2370	91	if (eft->year < 1900 \|\| eft->year > 9999)
6e85bab6	92	return false;
b2bd2370	93	wtime->tm_year = eft->year - 1900;
5e3fd9e5	94
	95	/* day in the year [1-365]*/
	96	wtime->tm_yday = compute_yday(eft);
	97
b2bd2370 AB	98	/* day of the week [0-6], Sunday=0 */
b2bd2370 AB	99	wtime->tm_wday = compute_wday(eft, wtime->tm_yday);
5e3fd9e5	100
	101	switch (eft->daylight & EFI_ISDST) {
	102	case EFI_ISDST:
	103	wtime->tm_isdst = 1;
	104	break;
	105	case EFI_TIME_ADJUST_DAYLIGHT:
	106	wtime->tm_isdst = 0;
	107	break;
	108	default:
	109	wtime->tm_isdst = -1;
	110	}
6e85bab6 JB	111
6e85bab6 JB	112	return true;
5e3fd9e5	113	}
	114
	115	static int efi_read_alarm(struct device dev, struct rtc_wkalrm wkalrm)
	116	{
	117	efi_time_t eft;
	118	efi_status_t status;
	119
	120	/*
	121	* As of EFI v1.10, this call always returns an unsupported status
	122	*/
	123	status = efi.get_wakeup_time((efi_bool_t *)&wkalrm->enabled,
	124	(efi_bool_t *)&wkalrm->pending, &eft);
	125
	126	if (status != EFI_SUCCESS)
	127	return -EINVAL;
	128
6e85bab6 JB	129	if (!convert_from_efi_time(&eft, &wkalrm->time))
6e85bab6 JB	130	return -EIO;
5e3fd9e5	131
	132	return rtc_valid_tm(&wkalrm->time);
	133	}
	134
	135	static int efi_set_alarm(struct device dev, struct rtc_wkalrm wkalrm)
	136	{
	137	efi_time_t eft;
	138	efi_status_t status;
	139
	140	convert_to_efi_time(&wkalrm->time, &eft);
	141
	142	/*
	143	* XXX Fixme:
	144	* As of EFI 0.92 with the firmware I have on my
	145	* machine this call does not seem to work quite
	146	* right
	147	*
	148	* As of v1.10, this call always returns an unsupported status
	149	*/
	150	status = efi.set_wakeup_time((efi_bool_t)wkalrm->enabled, &eft);
	151
34650f9e	152	dev_warn(dev, "write status is %d\n", (int)status);
5e3fd9e5	153
	154	return status == EFI_SUCCESS ? 0 : -EINVAL;
	155	}
	156
	157	static int efi_read_time(struct device dev, struct rtc_time tm)
	158	{
	159	efi_status_t status;
	160	efi_time_t eft;
	161	efi_time_cap_t cap;
	162
	163	status = efi.get_time(&eft, &cap);
	164
	165	if (status != EFI_SUCCESS) {
	166	/* should never happen */
34650f9e	167	dev_err(dev, "can't read time\n");
5e3fd9e5	168	return -EINVAL;
	169	}
	170
6e85bab6 JB	171	if (!convert_from_efi_time(&eft, tm))
6e85bab6 JB	172	return -EIO;
5e3fd9e5	173
22652ba7	174	return 0;
5e3fd9e5	175	}
	176
	177	static int efi_set_time(struct device dev, struct rtc_time tm)
	178	{
	179	efi_status_t status;
	180	efi_time_t eft;
	181
	182	convert_to_efi_time(tm, &eft);
	183
	184	status = efi.set_time(&eft);
	185
	186	return status == EFI_SUCCESS ? 0 : -EINVAL;
	187	}
	188
501385f2 GT	189	static int efi_procfs(struct device dev, struct seq_file seq)
	190	{
	191	efi_time_t eft, alm;
	192	efi_time_cap_t cap;
	193	efi_bool_t enabled, pending;
	194
	195	memset(&eft, 0, sizeof(eft));
	196	memset(&alm, 0, sizeof(alm));
	197	memset(&cap, 0, sizeof(cap));
	198
	199	efi.get_time(&eft, &cap);
	200	efi.get_wakeup_time(&enabled, &pending, &alm);
	201
	202	seq_printf(seq,
	203	"Time\t\t: %u:%u:%u.%09u\n"
	204	"Date\t\t: %u-%u-%u\n"
	205	"Daylight\t: %u\n",
	206	eft.hour, eft.minute, eft.second, eft.nanosecond,
	207	eft.year, eft.month, eft.day,
	208	eft.daylight);
	209
	210	if (eft.timezone == EFI_UNSPECIFIED_TIMEZONE)
	211	seq_puts(seq, "Timezone\t: unspecified\n");
	212	else
	213	/* XXX fixme: convert to string? */
	214	seq_printf(seq, "Timezone\t: %u\n", eft.timezone);
	215
	216	seq_printf(seq,
	217	"Alarm Time\t: %u:%u:%u.%09u\n"
	218	"Alarm Date\t: %u-%u-%u\n"
	219	"Alarm Daylight\t: %u\n"
	220	"Enabled\t\t: %s\n"
	221	"Pending\t\t: %s\n",
	222	alm.hour, alm.minute, alm.second, alm.nanosecond,
	223	alm.year, alm.month, alm.day,
	224	alm.daylight,
	225	enabled == 1 ? "yes" : "no",
	226	pending == 1 ? "yes" : "no");
	227
	228	if (eft.timezone == EFI_UNSPECIFIED_TIMEZONE)
	229	seq_puts(seq, "Timezone\t: unspecified\n");
	230	else
	231	/* XXX fixme: convert to string? */
	232	seq_printf(seq, "Timezone\t: %u\n", alm.timezone);
	233
	234	/*
	235	* now prints the capabilities
	236	*/
	237	seq_printf(seq,
	238	"Resolution\t: %u\n"
	239	"Accuracy\t: %u\n"
	240	"SetstoZero\t: %u\n",
	241	cap.resolution, cap.accuracy, cap.sets_to_zero);
	242
	243	return 0;
	244	}
	245
5e3fd9e5	246	static const struct rtc_class_ops efi_rtc_ops = {
501385f2 GT	247	.read_time = efi_read_time,
	248	.set_time = efi_set_time,
	249	.read_alarm = efi_read_alarm,
	250	.set_alarm = efi_set_alarm,
	251	.proc = efi_procfs,
5e3fd9e5	252	};
	253
	254	static int __init efi_rtc_probe(struct platform_device *dev)
	255	{
	256	struct rtc_device *rtc;
7368c69c AG	257	efi_time_t eft;
	258	efi_time_cap_t cap;
	259
	260	/* First check if the RTC is usable */
	261	if (efi.get_time(&eft, &cap) != EFI_SUCCESS)
	262	return -ENODEV;
5e3fd9e5	263
8aa74363	264	rtc = devm_rtc_allocate_device(&dev->dev);
5e3fd9e5	265	if (IS_ERR(rtc))
	266	return PTR_ERR(rtc);
	267
	268	platform_set_drvdata(dev, rtc);
	269
8aa74363	270	rtc->ops = &efi_rtc_ops;
1350b94c AB	271	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features);
1350b94c AB	272	set_bit(RTC_FEATURE_ALARM_WAKEUP_ONLY, rtc->features);
8aa74363 AB	273
8aa74363 AB	274	return devm_rtc_register_device(rtc);
5e3fd9e5	275	}
5e3fd9e5	276
5e3fd9e5	277	static struct platform_driver efi_rtc_driver = {
	278	.driver = {
	279	.name = "rtc-efi",
5e3fd9e5	280	},
5e3fd9e5	281	};
5e3fd9e5	282
52c6ecbc	283	module_platform_driver_probe(efi_rtc_driver, efi_rtc_probe);
5e3fd9e5	284
37563e5e	285	MODULE_AUTHOR("dann frazier <dannf@dannf.org>");
5e3fd9e5	286	MODULE_LICENSE("GPL");
5e3fd9e5	287	MODULE_DESCRIPTION("EFI RTC driver");
3f71f6da	288	MODULE_ALIAS("platform:rtc-efi");