Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
Arnd Bergmann | 759 | 84.43% | 1 | 14.29% |
Thomas Gleixner | 138 | 15.35% | 5 | 71.43% |
Eric Wong | 2 | 0.22% | 1 | 14.29% |
Total | 899 | 7 |
// SPDX-License-Identifier: GPL-2.0-only #include <linux/bcd.h> #include <linux/delay.h> #include <linux/export.h> #include <linux/mc146818rtc.h> #ifdef CONFIG_ACPI #include <linux/acpi.h> #endif unsigned int mc146818_get_time(struct rtc_time *time) { unsigned char ctrl; unsigned long flags; unsigned char century = 0; bool retry; #ifdef CONFIG_MACH_DECSTATION unsigned int real_year; #endif again: spin_lock_irqsave(&rtc_lock, flags); /* Ensure that the RTC is accessible. Bit 6 must be 0! */ if (WARN_ON_ONCE((CMOS_READ(RTC_VALID) & 0x40) != 0)) { spin_unlock_irqrestore(&rtc_lock, flags); memset(time, 0xff, sizeof(*time)); return 0; } /* * Check whether there is an update in progress during which the * readout is unspecified. The maximum update time is ~2ms. Poll * every msec for completion. * * Store the second value before checking UIP so a long lasting NMI * which happens to hit after the UIP check cannot make an update * cycle invisible. */ time->tm_sec = CMOS_READ(RTC_SECONDS); if (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP) { spin_unlock_irqrestore(&rtc_lock, flags); mdelay(1); goto again; } /* Revalidate the above readout */ if (time->tm_sec != CMOS_READ(RTC_SECONDS)) { spin_unlock_irqrestore(&rtc_lock, flags); goto again; } /* * Only the values that we read from the RTC are set. We leave * tm_wday, tm_yday and tm_isdst untouched. Even though the * RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated * by the RTC when initially set to a non-zero value. */ time->tm_min = CMOS_READ(RTC_MINUTES); time->tm_hour = CMOS_READ(RTC_HOURS); time->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH); time->tm_mon = CMOS_READ(RTC_MONTH); time->tm_year = CMOS_READ(RTC_YEAR); #ifdef CONFIG_MACH_DECSTATION real_year = CMOS_READ(RTC_DEC_YEAR); #endif #ifdef CONFIG_ACPI if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID && acpi_gbl_FADT.century) century = CMOS_READ(acpi_gbl_FADT.century); #endif ctrl = CMOS_READ(RTC_CONTROL); /* * Check for the UIP bit again. If it is set now then * the above values may contain garbage. */ retry = CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP; /* * A NMI might have interrupted the above sequence so check whether * the seconds value has changed which indicates that the NMI took * longer than the UIP bit was set. Unlikely, but possible and * there is also virt... */ retry |= time->tm_sec != CMOS_READ(RTC_SECONDS); spin_unlock_irqrestore(&rtc_lock, flags); if (retry) goto again; if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { time->tm_sec = bcd2bin(time->tm_sec); time->tm_min = bcd2bin(time->tm_min); time->tm_hour = bcd2bin(time->tm_hour); time->tm_mday = bcd2bin(time->tm_mday); time->tm_mon = bcd2bin(time->tm_mon); time->tm_year = bcd2bin(time->tm_year); century = bcd2bin(century); } #ifdef CONFIG_MACH_DECSTATION time->tm_year += real_year - 72; #endif if (century > 20) time->tm_year += (century - 19) * 100; /* * Account for differences between how the RTC uses the values * and how they are defined in a struct rtc_time; */ if (time->tm_year <= 69) time->tm_year += 100; time->tm_mon--; return RTC_24H; } EXPORT_SYMBOL_GPL(mc146818_get_time); /* Set the current date and time in the real time clock. */ int mc146818_set_time(struct rtc_time *time) { unsigned long flags; unsigned char mon, day, hrs, min, sec; unsigned char save_control, save_freq_select; unsigned int yrs; #ifdef CONFIG_MACH_DECSTATION unsigned int real_yrs, leap_yr; #endif unsigned char century = 0; yrs = time->tm_year; mon = time->tm_mon + 1; /* tm_mon starts at zero */ day = time->tm_mday; hrs = time->tm_hour; min = time->tm_min; sec = time->tm_sec; if (yrs > 255) /* They are unsigned */ return -EINVAL; #ifdef CONFIG_MACH_DECSTATION real_yrs = yrs; leap_yr = ((!((yrs + 1900) % 4) && ((yrs + 1900) % 100)) || !((yrs + 1900) % 400)); yrs = 72; /* * We want to keep the year set to 73 until March * for non-leap years, so that Feb, 29th is handled * correctly. */ if (!leap_yr && mon < 3) { real_yrs--; yrs = 73; } #endif #ifdef CONFIG_ACPI if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID && acpi_gbl_FADT.century) { century = (yrs + 1900) / 100; yrs %= 100; } #endif /* These limits and adjustments are independent of * whether the chip is in binary mode or not. */ if (yrs > 169) return -EINVAL; if (yrs >= 100) yrs -= 100; if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { sec = bin2bcd(sec); min = bin2bcd(min); hrs = bin2bcd(hrs); day = bin2bcd(day); mon = bin2bcd(mon); yrs = bin2bcd(yrs); century = bin2bcd(century); } spin_lock_irqsave(&rtc_lock, flags); save_control = CMOS_READ(RTC_CONTROL); CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL); save_freq_select = CMOS_READ(RTC_FREQ_SELECT); CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT); #ifdef CONFIG_MACH_DECSTATION CMOS_WRITE(real_yrs, RTC_DEC_YEAR); #endif CMOS_WRITE(yrs, RTC_YEAR); CMOS_WRITE(mon, RTC_MONTH); CMOS_WRITE(day, RTC_DAY_OF_MONTH); CMOS_WRITE(hrs, RTC_HOURS); CMOS_WRITE(min, RTC_MINUTES); CMOS_WRITE(sec, RTC_SECONDS); #ifdef CONFIG_ACPI if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID && acpi_gbl_FADT.century) CMOS_WRITE(century, acpi_gbl_FADT.century); #endif CMOS_WRITE(save_control, RTC_CONTROL); CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT); spin_unlock_irqrestore(&rtc_lock, flags); return 0; } EXPORT_SYMBOL_GPL(mc146818_set_time);
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