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path: root/drivers/rtc/rtc-efi.c
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Diffstat (limited to 'drivers/rtc/rtc-efi.c')
-rw-r--r--drivers/rtc/rtc-efi.c179
1 files changed, 94 insertions, 85 deletions
diff --git a/drivers/rtc/rtc-efi.c b/drivers/rtc/rtc-efi.c
index 797aa0252ba9..b4f44999ef0f 100644
--- a/drivers/rtc/rtc-efi.c
+++ b/drivers/rtc/rtc-efi.c
@@ -1,32 +1,24 @@
+// 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@hp.com>
+ * Author: dann frazier <dannf@dannf.org>
* Based on efirtc.c by Stephane Eranian
- *
- * 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.
- *
*/
#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)
-/*
- * EFI Epoch is 1/1/1998
- */
-#define EFI_RTC_EPOCH 1998
/*
* returns day of the year [0-365]
@@ -35,33 +27,26 @@ 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 - 1, eft->month - 1, eft->year);
+ return rtc_year_days(eft->day, eft->month - 1, eft->year);
}
+
/*
* returns day of the week [0-6] 0=Sunday
- *
- * Don't try to provide a year that's before 1998, please !
*/
static int
-compute_wday(efi_time_t *eft)
+compute_wday(efi_time_t *eft, int yday)
{
- int y;
- int ndays = 0;
-
- if (eft->year < 1998) {
- pr_err("EFI year < 1998, invalid date\n");
- return -1;
- }
-
- for (y = EFI_RTC_EPOCH; y < eft->year; y++)
- ndays += 365 + (is_leap_year(y) ? 1 : 0);
-
- ndays += compute_yday(eft);
+ int ndays = eft->year * (365 % 7)
+ + (eft->year - 1) / 4
+ - (eft->year - 1) / 100
+ + (eft->year - 1) / 400
+ + yday;
/*
- * 4=1/1/1998 was a Thursday
+ * 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 + 4) % 7;
+ return ndays % 7;
}
static void
@@ -78,23 +63,40 @@ convert_to_efi_time(struct rtc_time *wtime, efi_time_t *eft)
eft->timezone = EFI_UNSPECIFIED_TIMEZONE;
}
-static void
+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;
- wtime->tm_year = eft->year - 1900;
- /* day of the week [0-6], Sunday=0 */
- wtime->tm_wday = compute_wday(eft);
+ 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:
@@ -106,47 +108,8 @@ convert_from_efi_time(efi_time_t *eft, struct rtc_time *wtime)
default:
wtime->tm_isdst = -1;
}
-}
-
-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;
-
- convert_from_efi_time(&eft, &wkalrm->time);
- 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;
+ return true;
}
static int efi_read_time(struct device *dev, struct rtc_time *tm)
@@ -159,13 +122,14 @@ static int efi_read_time(struct device *dev, struct rtc_time *tm)
if (status != EFI_SUCCESS) {
/* should never happen */
- dev_err(dev, "can't read time\n");
+ dev_err_once(dev, "can't read time\n");
return -EINVAL;
}
- convert_from_efi_time(&eft, tm);
+ if (!convert_from_efi_time(&eft, tm))
+ return -EIO;
- return rtc_valid_tm(tm);
+ return 0;
}
static int efi_set_time(struct device *dev, struct rtc_time *tm)
@@ -180,36 +144,81 @@ static int efi_set_time(struct device *dev, struct rtc_time *tm)
return status == EFI_SUCCESS ? 0 : -EINVAL;
}
+static int efi_procfs(struct device *dev, struct seq_file *seq)
+{
+ efi_time_t eft;
+ efi_time_cap_t cap;
+
+ memset(&eft, 0, sizeof(eft));
+ memset(&cap, 0, sizeof(cap));
+
+ efi.get_time(&eft, &cap);
+
+ 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);
+
+ /*
+ * 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,
+ .read_time = efi_read_time,
+ .set_time = efi_set_time,
+ .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);
+ rtc = devm_rtc_allocate_device(&dev->dev);
if (IS_ERR(rtc))
return PTR_ERR(rtc);
platform_set_drvdata(dev, rtc);
- return 0;
+ rtc->ops = &efi_rtc_ops;
+ clear_bit(RTC_FEATURE_ALARM, rtc->features);
+
+ device_init_wakeup(&dev->dev, true);
+
+ return devm_rtc_register_device(rtc);
}
static struct platform_driver efi_rtc_driver = {
.driver = {
.name = "rtc-efi",
- .owner = THIS_MODULE,
},
};
module_platform_driver_probe(efi_rtc_driver, efi_rtc_probe);
-MODULE_AUTHOR("dann frazier <dannf@hp.com>");
+MODULE_AUTHOR("dann frazier <dannf@dannf.org>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("EFI RTC driver");
+MODULE_ALIAS("platform:rtc-efi");
generated by cgit (git 2.34.1) at 2025-12-25 02:46:26 +0000