/****************************************************************************/ /* * linux/arch/sh/boards/snapgear/rtc.c -- Secureedge5410 RTC code * * Copyright (C) 2002 David McCullough * Copyright (C) 2003 Paul Mundt * * The SecureEdge5410 can have one of 2 real time clocks, the SH * built in version or the preferred external DS1302. Here we work out * each to see what we have and then run with it. */ /****************************************************************************/ #include #include #include #include #include #include #include /****************************************************************************/ static int use_ds1302 = 0; /****************************************************************************/ /* * we need to implement a DS1302 driver here that can operate in * conjunction with the builtin rtc driver which is already quite friendly */ /*****************************************************************************/ #define RTC_CMD_READ 0x81 /* Read command */ #define RTC_CMD_WRITE 0x80 /* Write command */ #define RTC_ADDR_YEAR 0x06 /* Address of year register */ #define RTC_ADDR_DAY 0x05 /* Address of day of week register */ #define RTC_ADDR_MON 0x04 /* Address of month register */ #define RTC_ADDR_DATE 0x03 /* Address of day of month register */ #define RTC_ADDR_HOUR 0x02 /* Address of hour register */ #define RTC_ADDR_MIN 0x01 /* Address of minute register */ #define RTC_ADDR_SEC 0x00 /* Address of second register */ #define RTC_RESET 0x1000 #define RTC_IODATA 0x0800 #define RTC_SCLK 0x0400 #define set_dirp(x) #define get_dirp(x) 0 #define set_dp(x) SECUREEDGE_WRITE_IOPORT(x, 0x1c00) #define get_dp(x) SECUREEDGE_READ_IOPORT() static void ds1302_sendbits(unsigned int val) { int i; for (i = 8; (i); i--, val >>= 1) { set_dp((get_dp() & ~RTC_IODATA) | ((val & 0x1) ? RTC_IODATA : 0)); set_dp(get_dp() | RTC_SCLK); // clock high set_dp(get_dp() & ~RTC_SCLK); // clock low } } static unsigned int ds1302_recvbits(void) { unsigned int val; int i; for (i = 0, val = 0; (i < 8); i++) { val |= (((get_dp() & RTC_IODATA) ? 1 : 0) << i); set_dp(get_dp() | RTC_SCLK); // clock high set_dp(get_dp() & ~RTC_SCLK); // clock low } return(val); } static unsigned int ds1302_readbyte(unsigned int addr) { unsigned int val; unsigned long flags; #if 0 printk("SnapGear RTC: ds1302_readbyte(addr=%x)\n", addr); #endif local_irq_save(flags); set_dirp(get_dirp() | RTC_RESET | RTC_IODATA | RTC_SCLK); set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK)); set_dp(get_dp() | RTC_RESET); ds1302_sendbits(((addr & 0x3f) << 1) | RTC_CMD_READ); set_dirp(get_dirp() & ~RTC_IODATA); val = ds1302_recvbits(); set_dp(get_dp() & ~RTC_RESET); local_irq_restore(flags); return(val); } static void ds1302_writebyte(unsigned int addr, unsigned int val) { unsigned long flags; #if 0 printk("SnapGear RTC: ds1302_writebyte(addr=%x)\n", addr); #endif local_irq_save(flags); set_dirp(get_dirp() | RTC_RESET | RTC_IODATA | RTC_SCLK); set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK)); set_dp(get_dp() | RTC_RESET); ds1302_sendbits(((addr & 0x3f) << 1) | RTC_CMD_WRITE); ds1302_sendbits(val); set_dp(get_dp() & ~RTC_RESET); local_irq_restore(flags); } static void ds1302_reset(void) { unsigned long flags; /* Hardware dependant reset/init */ local_irq_save(flags); set_dirp(get_dirp() | RTC_RESET | RTC_IODATA | RTC_SCLK); set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK)); local_irq_restore(flags); } /*****************************************************************************/ static inline int bcd2int(int val) { return((((val & 0xf0) >> 4) * 10) + (val & 0xf)); } static inline int int2bcd(int val) { return(((val / 10) << 4) + (val % 10)); } /*****************************************************************************/ /* * Write and Read some RAM in the DS1302, if it works assume it's there * Otherwise use the SH4 internal RTC */ void snapgear_rtc_gettimeofday(struct timespec *); int snapgear_rtc_settimeofday(const time_t); void __init secureedge5410_rtc_init(void) { unsigned char *test = "snapgear"; int i; ds1302_reset(); use_ds1302 = 1; for (i = 0; test[i]; i++) ds1302_writebyte(32 + i, test[i]); for (i = 0; test[i]; i++) if (ds1302_readbyte(32 + i) != test[i]) { use_ds1302 = 0; break; } if (use_ds1302) { rtc_sh_get_time = snapgear_rtc_gettimeofday; rtc_sh_set_time = snapgear_rtc_settimeofday; } else { rtc_sh_get_time = sh_rtc_gettimeofday; rtc_sh_set_time = sh_rtc_settimeofday; } printk("SnapGear RTC: using %s rtc.\n", use_ds1302 ? "ds1302" : "internal"); } /****************************************************************************/ /* * our generic interface that chooses the correct code to use */ void snapgear_rtc_gettimeofday(struct timespec *ts) { unsigned int sec, min, hr, day, mon, yr; if (!use_ds1302) { sh_rtc_gettimeofday(ts); return; } sec = bcd2int(ds1302_readbyte(RTC_ADDR_SEC)); min = bcd2int(ds1302_readbyte(RTC_ADDR_MIN)); hr = bcd2int(ds1302_readbyte(RTC_ADDR_HOUR)); day = bcd2int(ds1302_readbyte(RTC_ADDR_DATE)); mon = bcd2int(ds1302_readbyte(RTC_ADDR_MON)); yr = bcd2int(ds1302_readbyte(RTC_ADDR_YEAR)); bad_time: if (yr > 99 || mon < 1 || mon > 12 || day > 31 || day < 1 || hr > 23 || min > 59 || sec > 59) { printk(KERN_ERR "SnapGear RTC: invalid value, resetting to 1 Jan 2000\n"); ds1302_writebyte(RTC_ADDR_MIN, min = 0); ds1302_writebyte(RTC_ADDR_HOUR, hr = 0); ds1302_writebyte(RTC_ADDR_DAY, 7); ds1302_writebyte(RTC_ADDR_DATE, day = 1); ds1302_writebyte(RTC_ADDR_MON, mon = 1); ds1302_writebyte(RTC_ADDR_YEAR, yr = 0); ds1302_writebyte(RTC_ADDR_SEC, sec = 0); } ts->tv_sec = mktime(2000 + yr, mon, day, hr, min, sec); if (ts->tv_sec < 0) { #if 0 printk("BAD TIME %d %d %d %d %d %d\n", yr, mon, day, hr, min, sec); #endif yr = 100; goto bad_time; } ts->tv_nsec = 0; } int snapgear_rtc_settimeofday(const time_t secs) { int retval = 0; int real_seconds, real_minutes, cmos_minutes; unsigned long nowtime; if (!use_ds1302) return sh_rtc_settimeofday(secs); /* * This is called direct from the kernel timer handling code. * It is supposed to synchronize the kernel clock to the RTC. */ nowtime = secs; #if 1 printk("SnapGear RTC: snapgear_rtc_settimeofday(nowtime=%ld)\n", nowtime); #endif /* STOP RTC */ ds1302_writebyte(RTC_ADDR_SEC, ds1302_readbyte(RTC_ADDR_SEC) | 0x80); cmos_minutes = bcd2int(ds1302_readbyte(RTC_ADDR_MIN)); /* * 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) { ds1302_writebyte(RTC_ADDR_MIN, int2bcd(real_minutes)); ds1302_writebyte(RTC_ADDR_SEC, int2bcd(real_seconds)); } else { printk(KERN_WARNING "SnapGear RTC: can't update from %d to %d\n", cmos_minutes, real_minutes); retval = -1; } /* START RTC */ ds1302_writebyte(RTC_ADDR_SEC, ds1302_readbyte(RTC_ADDR_SEC) & ~0x80); return(0); } unsigned char secureedge5410_cmos_read(int addr) { unsigned char val = 0; if (!use_ds1302) return(__CMOS_READ(addr, w)); switch(addr) { case RTC_SECONDS: val = ds1302_readbyte(RTC_ADDR_SEC); break; case RTC_SECONDS_ALARM: break; case RTC_MINUTES: val = ds1302_readbyte(RTC_ADDR_MIN); break; case RTC_MINUTES_ALARM: break; case RTC_HOURS: val = ds1302_readbyte(RTC_ADDR_HOUR); break; case RTC_HOURS_ALARM: break; case RTC_DAY_OF_WEEK: val = ds1302_readbyte(RTC_ADDR_DAY); break; case RTC_DAY_OF_MONTH: val = ds1302_readbyte(RTC_ADDR_DATE); break; case RTC_MONTH: val = ds1302_readbyte(RTC_ADDR_MON); break; case RTC_YEAR: val = ds1302_readbyte(RTC_ADDR_YEAR); break; case RTC_REG_A: /* RTC_FREQ_SELECT */ break; case RTC_REG_B: /* RTC_CONTROL */ break; case RTC_REG_C: /* RTC_INTR_FLAGS */ break; case RTC_REG_D: val = RTC_VRT /* RTC_VALID */; break; default: break; } return(val); } void secureedge5410_cmos_write(unsigned char val, int addr) { if (!use_ds1302) { __CMOS_WRITE(val, addr, w); return; } switch(addr) { case RTC_SECONDS: ds1302_writebyte(RTC_ADDR_SEC, val); break; case RTC_SECONDS_ALARM: break; case RTC_MINUTES: ds1302_writebyte(RTC_ADDR_MIN, val); break; case RTC_MINUTES_ALARM: break; case RTC_HOURS: ds1302_writebyte(RTC_ADDR_HOUR, val); break; case RTC_HOURS_ALARM: break; case RTC_DAY_OF_WEEK: ds1302_writebyte(RTC_ADDR_DAY, val); break; case RTC_DAY_OF_MONTH: ds1302_writebyte(RTC_ADDR_DATE, val); break; case RTC_MONTH: ds1302_writebyte(RTC_ADDR_MON, val); break; case RTC_YEAR: ds1302_writebyte(RTC_ADDR_YEAR, val); break; case RTC_REG_A: /* RTC_FREQ_SELECT */ break; case RTC_REG_B: /* RTC_CONTROL */ break; case RTC_REG_C: /* RTC_INTR_FLAGS */ break; case RTC_REG_D: /* RTC_VALID */ break; default: break; } } /****************************************************************************/