diff options
Diffstat (limited to 'include/asm-generic/rtc.h')
| -rw-r--r-- | include/asm-generic/rtc.h | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/include/asm-generic/rtc.h b/include/asm-generic/rtc.h new file mode 100644 index 00000000000..cef08db34ad --- /dev/null +++ b/include/asm-generic/rtc.h @@ -0,0 +1,213 @@ +/* + * inclue/asm-generic/rtc.h + * + * Author: Tom Rini <trini@mvista.com> + * + * Based on: + * drivers/char/rtc.c + * + * Please read the COPYING file for all license details. + */ + +#ifndef __ASM_RTC_H__ +#define __ASM_RTC_H__ + +#ifdef __KERNEL__ + +#include <linux/mc146818rtc.h> +#include <linux/rtc.h> +#include <linux/bcd.h> + +#define RTC_PIE 0x40 /* periodic interrupt enable */ +#define RTC_AIE 0x20 /* alarm interrupt enable */ +#define RTC_UIE 0x10 /* update-finished interrupt enable */ + +/* some dummy definitions */ +#define RTC_BATT_BAD 0x100 /* battery bad */ +#define RTC_SQWE 0x08 /* enable square-wave output */ +#define RTC_DM_BINARY 0x04 /* all time/date values are BCD if clear */ +#define RTC_24H 0x02 /* 24 hour mode - else hours bit 7 means pm */ +#define RTC_DST_EN 0x01 /* auto switch DST - works f. USA only */ + +/* + * Returns true if a clock update is in progress + */ +static inline unsigned char rtc_is_updating(void) +{ + unsigned char uip; + + spin_lock_irq(&rtc_lock); + uip = (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP); + spin_unlock_irq(&rtc_lock); + return uip; +} + +static inline unsigned int get_rtc_time(struct rtc_time *time) +{ + unsigned long uip_watchdog = jiffies; + unsigned char ctrl; +#ifdef CONFIG_MACH_DECSTATION + unsigned int real_year; +#endif + + /* + * read RTC once any update in progress is done. The update + * can take just over 2ms. We wait 10 to 20ms. There is no need to + * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP. + * If you need to know *exactly* when a second has started, enable + * periodic update complete interrupts, (via ioctl) and then + * immediately read /dev/rtc which will block until you get the IRQ. + * Once the read clears, read the RTC time (again via ioctl). Easy. + */ + + if (rtc_is_updating() != 0) + while (jiffies - uip_watchdog < 2*HZ/100) { + barrier(); + cpu_relax(); + } + + /* + * 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. + */ + spin_lock_irq(&rtc_lock); + time->tm_sec = CMOS_READ(RTC_SECONDS); + 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 + ctrl = CMOS_READ(RTC_CONTROL); + spin_unlock_irq(&rtc_lock); + + if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) + { + BCD_TO_BIN(time->tm_sec); + BCD_TO_BIN(time->tm_min); + BCD_TO_BIN(time->tm_hour); + BCD_TO_BIN(time->tm_mday); + BCD_TO_BIN(time->tm_mon); + BCD_TO_BIN(time->tm_year); + } + +#ifdef CONFIG_MACH_DECSTATION + time->tm_year += real_year - 72; +#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 RTC_24H; +} + +/* Set the current date and time in the real time clock. */ +static inline int set_rtc_time(struct rtc_time *time) +{ + 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 + + 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; + + spin_lock_irq(&rtc_lock); +#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 + /* These limits and adjustments are independent of + * whether the chip is in binary mode or not. + */ + if (yrs > 169) { + spin_unlock_irq(&rtc_lock); + return -EINVAL; + } + + if (yrs >= 100) + yrs -= 100; + + if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) + || RTC_ALWAYS_BCD) { + BIN_TO_BCD(sec); + BIN_TO_BCD(min); + BIN_TO_BCD(hrs); + BIN_TO_BCD(day); + BIN_TO_BCD(mon); + BIN_TO_BCD(yrs); + } + + 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); + + CMOS_WRITE(save_control, RTC_CONTROL); + CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT); + + spin_unlock_irq(&rtc_lock); + + return 0; +} + +static inline unsigned int get_rtc_ss(void) +{ + struct rtc_time h; + + get_rtc_time(&h); + return h.tm_sec; +} + +static inline int get_rtc_pll(struct rtc_pll_info *pll) +{ + return -EINVAL; +} +static inline int set_rtc_pll(struct rtc_pll_info *pll) +{ + return -EINVAL; +} + +#endif /* __KERNEL__ */ +#endif /* __ASM_RTC_H__ */ |