/* * Copyright (C) 2000, 2001 Broadcom Corporation * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /* * Time routines for the swarm board. We pass all the hard stuff * through to the sb1250 handling code. Only thing we really keep * track of here is what time of day we think it is. And we don't * really even do a good job of that... */ #include #include #include #include #include #include #include #include #include #include static unsigned long long sec_bias = 0; static unsigned int usec_bias = 0; extern rwlock_t xtime_lock; /* Xicor 1241 definitions */ /* * Register bits */ #define X1241REG_SR_BAT 0x80 /* currently on battery power */ #define X1241REG_SR_RWEL 0x04 /* r/w latch is enabled, can write RTC */ #define X1241REG_SR_WEL 0x02 /* r/w latch is unlocked, can enable r/w now */ #define X1241REG_SR_RTCF 0x01 /* clock failed */ #define X1241REG_BL_BP2 0x80 /* block protect 2 */ #define X1241REG_BL_BP1 0x40 /* block protect 1 */ #define X1241REG_BL_BP0 0x20 /* block protect 0 */ #define X1241REG_BL_WD1 0x10 #define X1241REG_BL_WD0 0x08 #define X1241REG_HR_MIL 0x80 /* military time format */ /* * Register numbers */ #define X1241REG_BL 0x10 /* block protect bits */ #define X1241REG_INT 0x11 /* */ #define X1241REG_SC 0x30 /* Seconds */ #define X1241REG_MN 0x31 /* Minutes */ #define X1241REG_HR 0x32 /* Hours */ #define X1241REG_DT 0x33 /* Day of month */ #define X1241REG_MO 0x34 /* Month */ #define X1241REG_YR 0x35 /* Year */ #define X1241REG_DW 0x36 /* Day of Week */ #define X1241REG_Y2K 0x37 /* Year 2K */ #define X1241REG_SR 0x3F /* Status register */ #define X1241_CCR_ADDRESS 0x6F #define SMB_CSR(reg) (KSEG1 | A_SMB_REGISTER(1, reg)) static int xicor_read(uint8_t addr) { while (in64(SMB_CSR(R_SMB_STATUS)) & M_SMB_BUSY) ; out64((addr >> 8) & 0x7, SMB_CSR(R_SMB_CMD)); out64((addr & 0xff), SMB_CSR(R_SMB_DATA)); out64((V_SMB_ADDR(X1241_CCR_ADDRESS) | V_SMB_TT_WR2BYTE), SMB_CSR(R_SMB_START)); while (in64(SMB_CSR(R_SMB_STATUS)) & M_SMB_BUSY) ; out64((V_SMB_ADDR(X1241_CCR_ADDRESS) | V_SMB_TT_RD1BYTE), SMB_CSR(R_SMB_START)); while (in64(SMB_CSR(R_SMB_STATUS)) & M_SMB_BUSY) ; if (in64(SMB_CSR(R_SMB_STATUS)) & M_SMB_ERROR) { /* Clear error bit by writing a 1 */ out64(M_SMB_ERROR, SMB_CSR(R_SMB_STATUS)); return -1; } return (in64(SMB_CSR(R_SMB_DATA)) & 0xff); } static int xicor_write(uint8_t addr, int b) { while (in64(SMB_CSR(R_SMB_STATUS)) & M_SMB_BUSY) ; out64(addr, SMB_CSR(R_SMB_CMD)); out64((addr & 0xff) | ((b & 0xff) << 8), SMB_CSR(R_SMB_DATA)); out64(V_SMB_ADDR(X1241_CCR_ADDRESS) | V_SMB_TT_WR3BYTE, SMB_CSR(R_SMB_START)); while (in64(SMB_CSR(R_SMB_STATUS)) & M_SMB_BUSY) ; if (in64(SMB_CSR(R_SMB_STATUS)) & M_SMB_ERROR) { /* Clear error bit by writing a 1 */ out64(M_SMB_ERROR, SMB_CSR(R_SMB_STATUS)); return -1; } else { return 0; } } #define BCD_TO_BIN(val) ((val)=((val)&15) + ((val)>>4)*10) #define BIN_TO_BCD(val) ((val)=(((val)/10)<<4) + (val)%10) /* * In order to set the CMOS clock precisely, set_rtc_mmss has to be * called 500 ms after the second nowtime has started, because when * nowtime is written into the registers of the CMOS clock, it will * jump to the next second precisely 500 ms later. Check the Motorola * MC146818A or Dallas DS12887 data sheet for details. * * BUG: This routine does not handle hour overflow properly; it just * sets the minutes. Usually you'll only notice that after reboot! */ int set_rtc_mmss(unsigned long nowtime) { int retval = 0; int real_seconds, real_minutes, cmos_minutes; cmos_minutes = xicor_read(X1241REG_MN); 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; /* unlock writes to the CCR */ xicor_write(X1241REG_SR, X1241REG_SR_WEL); xicor_write(X1241REG_SR, X1241REG_SR_WEL | X1241REG_SR_RWEL); if (abs(real_minutes - cmos_minutes) < 30) { BIN_TO_BCD(real_seconds); BIN_TO_BCD(real_minutes); xicor_write(X1241REG_SC, real_seconds); xicor_write(X1241REG_MN, real_minutes); } else { printk(KERN_WARNING "set_rtc_mmss: can't update from %d to %d\n", cmos_minutes, real_minutes); retval = -1; } xicor_write(X1241REG_SR, 0); printk("set_rtc_mmss: %02d:%02d\n", real_minutes, real_seconds); return retval; } static unsigned long __init get_swarm_time(void) { unsigned int year, mon, day, hour, min, sec, y2k; sec = xicor_read(X1241REG_SC); min = xicor_read(X1241REG_MN); hour = xicor_read(X1241REG_HR); if (hour & X1241REG_HR_MIL) { hour &= 0x3f; } else { if (hour & 0x20) hour = (hour & 0xf) + 0x12; } BCD_TO_BIN(sec); BCD_TO_BIN(min); BCD_TO_BIN(hour); day = xicor_read(X1241REG_DT); mon = xicor_read(X1241REG_MO); year = xicor_read(X1241REG_YR); y2k = xicor_read(X1241REG_Y2K); BCD_TO_BIN(day); BCD_TO_BIN(mon); BCD_TO_BIN(year); BCD_TO_BIN(y2k); year += (y2k * 100); return mktime(year, mon, day, hour, min, sec); } /* * Bring up the timer at 100 Hz. */ void __init time_init(void) { unsigned int flags; int status; /* Set up the scd general purpose timer 0 to cpu 0 */ sb1250_time_init(); /* Establish communication with the Xicor 1241 RTC */ /* XXXKW how do I share the SMBus with the I2C subsystem? */ out64(K_SMB_FREQ_400KHZ, SMB_CSR(R_SMB_FREQ)); out64(0, SMB_CSR(R_SMB_CONTROL)); if ((status = xicor_read(X1241REG_SR_RTCF)) < 0) { printk("x1241: couldn't detect on SWARM SMBus 1\n"); } else { if (status & X1241REG_SR_RTCF) printk("x1241: battery failed -- time is probably wrong\n"); write_lock_irqsave (&xtime_lock, flags); xtime.tv_sec = get_swarm_time(); xtime.tv_usec = 0; write_unlock_irqrestore(&xtime_lock, flags); } } void do_settimeofday(struct timeval *tv) { unsigned long saved_jiffies; unsigned long flags; saved_jiffies = jiffies; write_lock_irqsave(&xtime_lock, flags); sec_bias = (saved_jiffies/HZ) - tv->tv_sec; usec_bias = ((saved_jiffies%HZ)*(1000000/HZ)) - tv->tv_usec; write_unlock_irqrestore(&xtime_lock, flags); } void do_gettimeofday(struct timeval *tv) { unsigned long saved_jiffies; unsigned long flags; saved_jiffies = jiffies; read_lock_irqsave(&xtime_lock, flags); tv->tv_sec = sec_bias + (saved_jiffies/HZ); tv->tv_usec = usec_bias + ((saved_jiffies%HZ) * (1000000/HZ)); read_unlock_irqrestore(&xtime_lock, flags); }