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![Sylvain Chouleur](/assets/img/avatar_default.png)
If century field is supported by the RTC CMOS device, then we should use it and then do not consider years greater that 169 as an error. For information, the year field of the rtc_time structure contains the value to add to 1970 to obtain the current year. This was a hack to be able to support years for 1970 to 2069. This patch remains compatible with this implementation. Signed-off-by: Sylvain Chouleur <sylvain.chouleur@intel.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
247 lines
6 KiB
C
247 lines
6 KiB
C
/*
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* include/asm-generic/rtc.h
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*
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* Author: Tom Rini <trini@mvista.com>
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*
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* Based on:
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* drivers/char/rtc.c
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*
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* Please read the COPYING file for all license details.
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*/
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#ifndef __ASM_RTC_H__
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#define __ASM_RTC_H__
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#include <linux/mc146818rtc.h>
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#include <linux/rtc.h>
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#include <linux/bcd.h>
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#include <linux/delay.h>
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#ifdef CONFIG_ACPI
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#include <linux/acpi.h>
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#endif
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#define RTC_PIE 0x40 /* periodic interrupt enable */
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#define RTC_AIE 0x20 /* alarm interrupt enable */
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#define RTC_UIE 0x10 /* update-finished interrupt enable */
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/* some dummy definitions */
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#define RTC_BATT_BAD 0x100 /* battery bad */
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#define RTC_SQWE 0x08 /* enable square-wave output */
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#define RTC_DM_BINARY 0x04 /* all time/date values are BCD if clear */
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#define RTC_24H 0x02 /* 24 hour mode - else hours bit 7 means pm */
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#define RTC_DST_EN 0x01 /* auto switch DST - works f. USA only */
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/*
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* Returns true if a clock update is in progress
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*/
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static inline unsigned char rtc_is_updating(void)
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{
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unsigned char uip;
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unsigned long flags;
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spin_lock_irqsave(&rtc_lock, flags);
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uip = (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP);
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spin_unlock_irqrestore(&rtc_lock, flags);
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return uip;
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}
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static inline unsigned int __get_rtc_time(struct rtc_time *time)
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{
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unsigned char ctrl;
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unsigned long flags;
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unsigned char century = 0;
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#ifdef CONFIG_MACH_DECSTATION
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unsigned int real_year;
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#endif
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/*
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* read RTC once any update in progress is done. The update
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* can take just over 2ms. We wait 20ms. There is no need to
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* to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP.
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* If you need to know *exactly* when a second has started, enable
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* periodic update complete interrupts, (via ioctl) and then
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* immediately read /dev/rtc which will block until you get the IRQ.
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* Once the read clears, read the RTC time (again via ioctl). Easy.
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*/
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if (rtc_is_updating())
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mdelay(20);
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/*
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* Only the values that we read from the RTC are set. We leave
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* tm_wday, tm_yday and tm_isdst untouched. Even though the
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* RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated
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* by the RTC when initially set to a non-zero value.
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*/
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spin_lock_irqsave(&rtc_lock, flags);
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time->tm_sec = CMOS_READ(RTC_SECONDS);
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time->tm_min = CMOS_READ(RTC_MINUTES);
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time->tm_hour = CMOS_READ(RTC_HOURS);
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time->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH);
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time->tm_mon = CMOS_READ(RTC_MONTH);
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time->tm_year = CMOS_READ(RTC_YEAR);
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#ifdef CONFIG_MACH_DECSTATION
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real_year = CMOS_READ(RTC_DEC_YEAR);
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#endif
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#ifdef CONFIG_ACPI
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if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID &&
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acpi_gbl_FADT.century)
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century = CMOS_READ(acpi_gbl_FADT.century);
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#endif
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ctrl = CMOS_READ(RTC_CONTROL);
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spin_unlock_irqrestore(&rtc_lock, flags);
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if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
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{
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time->tm_sec = bcd2bin(time->tm_sec);
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time->tm_min = bcd2bin(time->tm_min);
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time->tm_hour = bcd2bin(time->tm_hour);
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time->tm_mday = bcd2bin(time->tm_mday);
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time->tm_mon = bcd2bin(time->tm_mon);
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time->tm_year = bcd2bin(time->tm_year);
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century = bcd2bin(century);
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}
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#ifdef CONFIG_MACH_DECSTATION
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time->tm_year += real_year - 72;
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#endif
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if (century)
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time->tm_year += (century - 19) * 100;
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/*
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* Account for differences between how the RTC uses the values
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* and how they are defined in a struct rtc_time;
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*/
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if (time->tm_year <= 69)
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time->tm_year += 100;
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time->tm_mon--;
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return RTC_24H;
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}
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#ifndef get_rtc_time
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#define get_rtc_time __get_rtc_time
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#endif
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/* Set the current date and time in the real time clock. */
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static inline int __set_rtc_time(struct rtc_time *time)
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{
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unsigned long flags;
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unsigned char mon, day, hrs, min, sec;
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unsigned char save_control, save_freq_select;
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unsigned int yrs;
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#ifdef CONFIG_MACH_DECSTATION
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unsigned int real_yrs, leap_yr;
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#endif
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unsigned char century = 0;
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yrs = time->tm_year;
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mon = time->tm_mon + 1; /* tm_mon starts at zero */
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day = time->tm_mday;
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hrs = time->tm_hour;
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min = time->tm_min;
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sec = time->tm_sec;
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if (yrs > 255) /* They are unsigned */
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return -EINVAL;
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spin_lock_irqsave(&rtc_lock, flags);
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#ifdef CONFIG_MACH_DECSTATION
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real_yrs = yrs;
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leap_yr = ((!((yrs + 1900) % 4) && ((yrs + 1900) % 100)) ||
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!((yrs + 1900) % 400));
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yrs = 72;
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/*
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* We want to keep the year set to 73 until March
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* for non-leap years, so that Feb, 29th is handled
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* correctly.
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*/
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if (!leap_yr && mon < 3) {
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real_yrs--;
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yrs = 73;
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}
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#endif
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#ifdef CONFIG_ACPI
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if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID &&
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acpi_gbl_FADT.century) {
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century = (yrs + 1900) / 100;
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yrs %= 100;
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}
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#endif
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/* These limits and adjustments are independent of
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* whether the chip is in binary mode or not.
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*/
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if (yrs > 169) {
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spin_unlock_irqrestore(&rtc_lock, flags);
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return -EINVAL;
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}
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if (yrs >= 100)
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yrs -= 100;
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if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY)
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|| RTC_ALWAYS_BCD) {
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sec = bin2bcd(sec);
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min = bin2bcd(min);
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hrs = bin2bcd(hrs);
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day = bin2bcd(day);
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mon = bin2bcd(mon);
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yrs = bin2bcd(yrs);
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century = bin2bcd(century);
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}
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save_control = CMOS_READ(RTC_CONTROL);
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CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL);
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save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
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CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
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#ifdef CONFIG_MACH_DECSTATION
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CMOS_WRITE(real_yrs, RTC_DEC_YEAR);
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#endif
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CMOS_WRITE(yrs, RTC_YEAR);
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CMOS_WRITE(mon, RTC_MONTH);
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CMOS_WRITE(day, RTC_DAY_OF_MONTH);
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CMOS_WRITE(hrs, RTC_HOURS);
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CMOS_WRITE(min, RTC_MINUTES);
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CMOS_WRITE(sec, RTC_SECONDS);
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#ifdef CONFIG_ACPI
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if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID &&
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acpi_gbl_FADT.century)
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CMOS_WRITE(century, acpi_gbl_FADT.century);
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#endif
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CMOS_WRITE(save_control, RTC_CONTROL);
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CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
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spin_unlock_irqrestore(&rtc_lock, flags);
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return 0;
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}
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#ifndef set_rtc_time
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#define set_rtc_time __set_rtc_time
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#endif
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static inline unsigned int get_rtc_ss(void)
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{
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struct rtc_time h;
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get_rtc_time(&h);
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return h.tm_sec;
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}
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static inline int get_rtc_pll(struct rtc_pll_info *pll)
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{
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return -EINVAL;
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}
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static inline int set_rtc_pll(struct rtc_pll_info *pll)
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{
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return -EINVAL;
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}
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#endif /* __ASM_RTC_H__ */
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