Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
Arnd Bergmann | 716 | 62.05% | 1 | 6.67% |
Mateusz Jończyk | 362 | 31.37% | 7 | 46.67% |
Mario Limonciello | 52 | 4.51% | 1 | 6.67% |
Thomas Gleixner | 22 | 1.91% | 4 | 26.67% |
Riwen Lu | 1 | 0.09% | 1 | 6.67% |
Eric Wong | 1 | 0.09% | 1 | 6.67% |
Total | 1154 | 15 |
// 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 /* * Execute a function while the UIP (Update-in-progress) bit of the RTC is * unset. * * Warning: callback may be executed more then once. */ bool mc146818_avoid_UIP(void (*callback)(unsigned char seconds, void *param), void *param) { int i; unsigned long flags; unsigned char seconds; for (i = 0; i < 100; i++) { spin_lock_irqsave(&rtc_lock, flags); /* * Check whether there is an update in progress during which the * readout is unspecified. The maximum update time is ~2ms. Poll * every 100 usec 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. */ seconds = CMOS_READ(RTC_SECONDS); if (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP) { spin_unlock_irqrestore(&rtc_lock, flags); udelay(100); continue; } /* Revalidate the above readout */ if (seconds != CMOS_READ(RTC_SECONDS)) { spin_unlock_irqrestore(&rtc_lock, flags); continue; } if (callback) callback(seconds, param); /* * Check for the UIP bit again. If it is set now then * the above values may contain garbage. */ if (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP) { spin_unlock_irqrestore(&rtc_lock, flags); udelay(100); continue; } /* * 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... */ if (seconds != CMOS_READ(RTC_SECONDS)) { spin_unlock_irqrestore(&rtc_lock, flags); continue; } spin_unlock_irqrestore(&rtc_lock, flags); return true; } return false; } EXPORT_SYMBOL_GPL(mc146818_avoid_UIP); /* * If the UIP (Update-in-progress) bit of the RTC is set for more then * 10ms, the RTC is apparently broken or not present. */ bool mc146818_does_rtc_work(void) { return mc146818_avoid_UIP(NULL, NULL); } EXPORT_SYMBOL_GPL(mc146818_does_rtc_work); struct mc146818_get_time_callback_param { struct rtc_time *time; unsigned char ctrl; #ifdef CONFIG_ACPI unsigned char century; #endif #ifdef CONFIG_MACH_DECSTATION unsigned int real_year; #endif }; static void mc146818_get_time_callback(unsigned char seconds, void *param_in) { struct mc146818_get_time_callback_param *p = param_in; /* * 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. */ p->time->tm_sec = seconds; p->time->tm_min = CMOS_READ(RTC_MINUTES); p->time->tm_hour = CMOS_READ(RTC_HOURS); p->time->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH); p->time->tm_mon = CMOS_READ(RTC_MONTH); p->time->tm_year = CMOS_READ(RTC_YEAR); #ifdef CONFIG_MACH_DECSTATION p->real_year = CMOS_READ(RTC_DEC_YEAR); #endif #ifdef CONFIG_ACPI if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID && acpi_gbl_FADT.century) { p->century = CMOS_READ(acpi_gbl_FADT.century); } else { p->century = 0; } #endif p->ctrl = CMOS_READ(RTC_CONTROL); } int mc146818_get_time(struct rtc_time *time) { struct mc146818_get_time_callback_param p = { .time = time }; if (!mc146818_avoid_UIP(mc146818_get_time_callback, &p)) { memset(time, 0, sizeof(*time)); return -EIO; } if (!(p.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); #ifdef CONFIG_ACPI p.century = bcd2bin(p.century); #endif } #ifdef CONFIG_MACH_DECSTATION time->tm_year += p.real_year - 72; #endif #ifdef CONFIG_ACPI if (p.century > 19) time->tm_year += (p.century - 19) * 100; #endif /* * 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 0; } EXPORT_SYMBOL_GPL(mc146818_get_time); /* AMD systems don't allow access to AltCentury with DV1 */ static bool apply_amd_register_a_behavior(void) { #ifdef CONFIG_X86 if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD || boot_cpu_data.x86_vendor == X86_VENDOR_HYGON) return true; #endif return false; } /* 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; spin_lock_irqsave(&rtc_lock, flags); save_control = CMOS_READ(RTC_CONTROL); spin_unlock_irqrestore(&rtc_lock, flags); if (!(save_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); if (apply_amd_register_a_behavior()) CMOS_WRITE((save_freq_select & ~RTC_AMD_BANK_SELECT), RTC_FREQ_SELECT); else 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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