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286 lines
6.3 KiB
286 lines
6.3 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* rtc-efi: RTC Class Driver for EFI-based systems |
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* |
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* Copyright (C) 2009 Hewlett-Packard Development Company, L.P. |
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* |
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* Author: dann frazier <[email protected]> |
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* Based on efirtc.c by Stephane Eranian |
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*/ |
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/stringify.h> |
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#include <linux/time.h> |
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#include <linux/platform_device.h> |
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#include <linux/rtc.h> |
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#include <linux/efi.h> |
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#define EFI_ISDST (EFI_TIME_ADJUST_DAYLIGHT|EFI_TIME_IN_DAYLIGHT) |
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/* |
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* returns day of the year [0-365] |
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*/ |
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static inline int |
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compute_yday(efi_time_t *eft) |
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{ |
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/* efi_time_t.month is in the [1-12] so, we need -1 */ |
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return rtc_year_days(eft->day, eft->month - 1, eft->year); |
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} |
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/* |
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* returns day of the week [0-6] 0=Sunday |
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*/ |
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static int |
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compute_wday(efi_time_t *eft, int yday) |
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{ |
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int ndays = eft->year * (365 % 7) |
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+ (eft->year - 1) / 4 |
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- (eft->year - 1) / 100 |
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+ (eft->year - 1) / 400 |
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+ yday; |
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/* |
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* 1/1/0000 may or may not have been a Sunday (if it ever existed at |
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* all) but assuming it was makes this calculation work correctly. |
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*/ |
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return ndays % 7; |
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} |
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static void |
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convert_to_efi_time(struct rtc_time *wtime, efi_time_t *eft) |
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{ |
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eft->year = wtime->tm_year + 1900; |
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eft->month = wtime->tm_mon + 1; |
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eft->day = wtime->tm_mday; |
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eft->hour = wtime->tm_hour; |
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eft->minute = wtime->tm_min; |
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eft->second = wtime->tm_sec; |
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eft->nanosecond = 0; |
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eft->daylight = wtime->tm_isdst ? EFI_ISDST : 0; |
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eft->timezone = EFI_UNSPECIFIED_TIMEZONE; |
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} |
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static bool |
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convert_from_efi_time(efi_time_t *eft, struct rtc_time *wtime) |
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{ |
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memset(wtime, 0, sizeof(*wtime)); |
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if (eft->second >= 60) |
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return false; |
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wtime->tm_sec = eft->second; |
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if (eft->minute >= 60) |
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return false; |
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wtime->tm_min = eft->minute; |
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if (eft->hour >= 24) |
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return false; |
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wtime->tm_hour = eft->hour; |
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if (!eft->day || eft->day > 31) |
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return false; |
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wtime->tm_mday = eft->day; |
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if (!eft->month || eft->month > 12) |
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return false; |
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wtime->tm_mon = eft->month - 1; |
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if (eft->year < 1900 || eft->year > 9999) |
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return false; |
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wtime->tm_year = eft->year - 1900; |
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/* day in the year [1-365]*/ |
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wtime->tm_yday = compute_yday(eft); |
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/* day of the week [0-6], Sunday=0 */ |
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wtime->tm_wday = compute_wday(eft, wtime->tm_yday); |
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switch (eft->daylight & EFI_ISDST) { |
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case EFI_ISDST: |
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wtime->tm_isdst = 1; |
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break; |
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case EFI_TIME_ADJUST_DAYLIGHT: |
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wtime->tm_isdst = 0; |
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break; |
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default: |
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wtime->tm_isdst = -1; |
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} |
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return true; |
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} |
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static int efi_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm) |
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{ |
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efi_time_t eft; |
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efi_status_t status; |
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/* |
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* As of EFI v1.10, this call always returns an unsupported status |
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*/ |
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status = efi.get_wakeup_time((efi_bool_t *)&wkalrm->enabled, |
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(efi_bool_t *)&wkalrm->pending, &eft); |
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if (status != EFI_SUCCESS) |
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return -EINVAL; |
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if (!convert_from_efi_time(&eft, &wkalrm->time)) |
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return -EIO; |
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return rtc_valid_tm(&wkalrm->time); |
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} |
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static int efi_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm) |
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{ |
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efi_time_t eft; |
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efi_status_t status; |
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convert_to_efi_time(&wkalrm->time, &eft); |
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/* |
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* XXX Fixme: |
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* As of EFI 0.92 with the firmware I have on my |
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* machine this call does not seem to work quite |
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* right |
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* |
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* As of v1.10, this call always returns an unsupported status |
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*/ |
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status = efi.set_wakeup_time((efi_bool_t)wkalrm->enabled, &eft); |
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dev_warn(dev, "write status is %d\n", (int)status); |
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return status == EFI_SUCCESS ? 0 : -EINVAL; |
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} |
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static int efi_read_time(struct device *dev, struct rtc_time *tm) |
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{ |
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efi_status_t status; |
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efi_time_t eft; |
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efi_time_cap_t cap; |
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status = efi.get_time(&eft, &cap); |
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if (status != EFI_SUCCESS) { |
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/* should never happen */ |
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dev_err(dev, "can't read time\n"); |
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return -EINVAL; |
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} |
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if (!convert_from_efi_time(&eft, tm)) |
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return -EIO; |
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return 0; |
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} |
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static int efi_set_time(struct device *dev, struct rtc_time *tm) |
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{ |
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efi_status_t status; |
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efi_time_t eft; |
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convert_to_efi_time(tm, &eft); |
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status = efi.set_time(&eft); |
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return status == EFI_SUCCESS ? 0 : -EINVAL; |
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} |
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static int efi_procfs(struct device *dev, struct seq_file *seq) |
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{ |
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efi_time_t eft, alm; |
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efi_time_cap_t cap; |
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efi_bool_t enabled, pending; |
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memset(&eft, 0, sizeof(eft)); |
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memset(&alm, 0, sizeof(alm)); |
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memset(&cap, 0, sizeof(cap)); |
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efi.get_time(&eft, &cap); |
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efi.get_wakeup_time(&enabled, &pending, &alm); |
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seq_printf(seq, |
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"Time\t\t: %u:%u:%u.%09u\n" |
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"Date\t\t: %u-%u-%u\n" |
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"Daylight\t: %u\n", |
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eft.hour, eft.minute, eft.second, eft.nanosecond, |
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eft.year, eft.month, eft.day, |
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eft.daylight); |
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if (eft.timezone == EFI_UNSPECIFIED_TIMEZONE) |
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seq_puts(seq, "Timezone\t: unspecified\n"); |
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else |
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/* XXX fixme: convert to string? */ |
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seq_printf(seq, "Timezone\t: %u\n", eft.timezone); |
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seq_printf(seq, |
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"Alarm Time\t: %u:%u:%u.%09u\n" |
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"Alarm Date\t: %u-%u-%u\n" |
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"Alarm Daylight\t: %u\n" |
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"Enabled\t\t: %s\n" |
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"Pending\t\t: %s\n", |
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alm.hour, alm.minute, alm.second, alm.nanosecond, |
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alm.year, alm.month, alm.day, |
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alm.daylight, |
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enabled == 1 ? "yes" : "no", |
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pending == 1 ? "yes" : "no"); |
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if (eft.timezone == EFI_UNSPECIFIED_TIMEZONE) |
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seq_puts(seq, "Timezone\t: unspecified\n"); |
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else |
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/* XXX fixme: convert to string? */ |
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seq_printf(seq, "Timezone\t: %u\n", alm.timezone); |
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/* |
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* now prints the capabilities |
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*/ |
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seq_printf(seq, |
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"Resolution\t: %u\n" |
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"Accuracy\t: %u\n" |
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"SetstoZero\t: %u\n", |
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cap.resolution, cap.accuracy, cap.sets_to_zero); |
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return 0; |
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} |
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static const struct rtc_class_ops efi_rtc_ops = { |
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.read_time = efi_read_time, |
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.set_time = efi_set_time, |
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.read_alarm = efi_read_alarm, |
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.set_alarm = efi_set_alarm, |
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.proc = efi_procfs, |
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}; |
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static int __init efi_rtc_probe(struct platform_device *dev) |
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{ |
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struct rtc_device *rtc; |
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efi_time_t eft; |
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efi_time_cap_t cap; |
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/* First check if the RTC is usable */ |
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if (efi.get_time(&eft, &cap) != EFI_SUCCESS) |
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return -ENODEV; |
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rtc = devm_rtc_device_register(&dev->dev, "rtc-efi", &efi_rtc_ops, |
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THIS_MODULE); |
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if (IS_ERR(rtc)) |
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return PTR_ERR(rtc); |
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rtc->uie_unsupported = 1; |
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platform_set_drvdata(dev, rtc); |
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return 0; |
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} |
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static struct platform_driver efi_rtc_driver = { |
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.driver = { |
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.name = "rtc-efi", |
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}, |
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}; |
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module_platform_driver_probe(efi_rtc_driver, efi_rtc_probe); |
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MODULE_AUTHOR("dann frazier <[email protected]>"); |
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MODULE_LICENSE("GPL"); |
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MODULE_DESCRIPTION("EFI RTC driver"); |
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MODULE_ALIAS("platform:rtc-efi");
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