diff options
Diffstat (limited to 'arch/sh/boards/snapgear/rtc.c')
| -rw-r--r-- | arch/sh/boards/snapgear/rtc.c | 333 |
1 files changed, 333 insertions, 0 deletions
diff --git a/arch/sh/boards/snapgear/rtc.c b/arch/sh/boards/snapgear/rtc.c new file mode 100644 index 000000000000..b71e009da35c --- /dev/null +++ b/arch/sh/boards/snapgear/rtc.c @@ -0,0 +1,333 @@ +/****************************************************************************/ +/* + * linux/arch/sh/boards/snapgear/rtc.c -- Secureedge5410 RTC code + * + * Copyright (C) 2002 David McCullough <davidm@snapgear.com> + * Copyright (C) 2003 Paul Mundt <lethal@linux-sh.org> + * + * 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 <linux/init.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/time.h> +#include <linux/rtc.h> +#include <linux/mc146818rtc.h> + +#include <asm/io.h> +#include <asm/rtc.h> +#include <asm/mc146818rtc.h> + +/****************************************************************************/ + +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_get_time = snapgear_rtc_gettimeofday; + rtc_set_time = snapgear_rtc_settimeofday; + } else { + rtc_get_time = sh_rtc_gettimeofday; + rtc_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; + } +} + +/****************************************************************************/ |