linux/drivers/rtc/rtc-efi.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

288 lines
6.3 KiB
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_device_register(&dev->dev, "rtc-efi", &efi_rtc_ops,
THIS_MODULE);
if (IS_ERR(rtc))
return PTR_ERR(rtc);
rtc->uie_unsupported = 1;
platform_set_drvdata(dev, rtc);
return 0;
}
static struct platform_driver efi_rtc_driver = {
.driver = {
.name = "rtc-efi",
},
};
module_platform_driver_probe(efi_rtc_driver, efi_rtc_probe);
MODULE_ALIAS("platform:rtc-efi");
MODULE_AUTHOR("dann frazier <dannf@dannf.org>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("EFI RTC driver");
MODULE_ALIAS("platform:rtc-efi");