| /* |
| * 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 |
| * |
| * 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) |
| |
| /* |
| * 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"); |