| /* |
| * arch/arm/mach-footbridge/include/mach/time.h |
| * |
| * Copyright (C) 1998 Russell King. |
| * Copyright (C) 1998 Phil Blundell |
| * |
| * CATS has a real-time clock, though the evaluation board doesn't. |
| * |
| * Changelog: |
| * 21-Mar-1998 RMK Created |
| * 27-Aug-1998 PJB CATS support |
| * 28-Dec-1998 APH Made leds optional |
| * 20-Jan-1999 RMK Started merge of EBSA285, CATS and NetWinder |
| * 16-Mar-1999 RMK More support for EBSA285-like machines with RTCs in |
| */ |
| |
| #define RTC_PORT(x) (rtc_base+(x)) |
| #define RTC_ALWAYS_BCD 0 |
| |
| #include <linux/timex.h> |
| #include <linux/init.h> |
| #include <linux/sched.h> |
| #include <linux/mc146818rtc.h> |
| #include <linux/bcd.h> |
| #include <linux/io.h> |
| |
| #include <mach/hardware.h> |
| |
| #include <asm/mach/time.h> |
| #include "common.h" |
| |
| static int rtc_base; |
| |
| static unsigned long __init get_isa_cmos_time(void) |
| { |
| unsigned int year, mon, day, hour, min, sec; |
| |
| // check to see if the RTC makes sense..... |
| if ((CMOS_READ(RTC_VALID) & RTC_VRT) == 0) |
| return mktime(1970, 1, 1, 0, 0, 0); |
| |
| do { |
| sec = CMOS_READ(RTC_SECONDS); |
| min = CMOS_READ(RTC_MINUTES); |
| hour = CMOS_READ(RTC_HOURS); |
| day = CMOS_READ(RTC_DAY_OF_MONTH); |
| mon = CMOS_READ(RTC_MONTH); |
| year = CMOS_READ(RTC_YEAR); |
| } while (sec != CMOS_READ(RTC_SECONDS)); |
| |
| if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { |
| BCD_TO_BIN(sec); |
| BCD_TO_BIN(min); |
| BCD_TO_BIN(hour); |
| BCD_TO_BIN(day); |
| BCD_TO_BIN(mon); |
| BCD_TO_BIN(year); |
| } |
| if ((year += 1900) < 1970) |
| year += 100; |
| return mktime(year, mon, day, hour, min, sec); |
| } |
| |
| static int set_isa_cmos_time(void) |
| { |
| int retval = 0; |
| int real_seconds, real_minutes, cmos_minutes; |
| unsigned char save_control, save_freq_select; |
| unsigned long nowtime = xtime.tv_sec; |
| |
| save_control = CMOS_READ(RTC_CONTROL); /* tell the clock it's being set */ |
| CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL); |
| |
| save_freq_select = CMOS_READ(RTC_FREQ_SELECT); /* stop and reset prescaler */ |
| CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT); |
| |
| cmos_minutes = CMOS_READ(RTC_MINUTES); |
| if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) |
| BCD_TO_BIN(cmos_minutes); |
| |
| /* |
| * since we're only adjusting minutes and seconds, |
| * don't interfere with hour overflow. This avoids |
| * messing with unknown time zones but requires your |
| * RTC not to be off by more than 15 minutes |
| */ |
| real_seconds = nowtime % 60; |
| real_minutes = nowtime / 60; |
| if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1) |
| real_minutes += 30; /* correct for half hour time zone */ |
| real_minutes %= 60; |
| |
| if (abs(real_minutes - cmos_minutes) < 30) { |
| if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { |
| BIN_TO_BCD(real_seconds); |
| BIN_TO_BCD(real_minutes); |
| } |
| CMOS_WRITE(real_seconds,RTC_SECONDS); |
| CMOS_WRITE(real_minutes,RTC_MINUTES); |
| } else |
| retval = -1; |
| |
| /* The following flags have to be released exactly in this order, |
| * otherwise the DS12887 (popular MC146818A clone with integrated |
| * battery and quartz) will not reset the oscillator and will not |
| * update precisely 500 ms later. You won't find this mentioned in |
| * the Dallas Semiconductor data sheets, but who believes data |
| * sheets anyway ... -- Markus Kuhn |
| */ |
| CMOS_WRITE(save_control, RTC_CONTROL); |
| CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT); |
| |
| return retval; |
| } |
| |
| void __init isa_rtc_init(void) |
| { |
| if (machine_is_personal_server()) |
| /* |
| * Add-in 21285s shouldn't access the RTC |
| */ |
| rtc_base = 0; |
| else |
| rtc_base = 0x70; |
| |
| if (rtc_base) { |
| int reg_d, reg_b; |
| |
| /* |
| * Probe for the RTC. |
| */ |
| reg_d = CMOS_READ(RTC_REG_D); |
| |
| /* |
| * make sure the divider is set |
| */ |
| CMOS_WRITE(RTC_REF_CLCK_32KHZ, RTC_REG_A); |
| |
| /* |
| * Set control reg B |
| * (24 hour mode, update enabled) |
| */ |
| reg_b = CMOS_READ(RTC_REG_B) & 0x7f; |
| reg_b |= 2; |
| CMOS_WRITE(reg_b, RTC_REG_B); |
| |
| if ((CMOS_READ(RTC_REG_A) & 0x7f) == RTC_REF_CLCK_32KHZ && |
| CMOS_READ(RTC_REG_B) == reg_b) { |
| struct timespec tv; |
| |
| /* |
| * We have a RTC. Check the battery |
| */ |
| if ((reg_d & 0x80) == 0) |
| printk(KERN_WARNING "RTC: *** warning: CMOS battery bad\n"); |
| |
| tv.tv_nsec = 0; |
| tv.tv_sec = get_isa_cmos_time(); |
| do_settimeofday(&tv); |
| set_rtc = set_isa_cmos_time; |
| } else |
| rtc_base = 0; |
| } |
| } |