arch/mips/sibyte/swarm/rtc_xicor1241.c

   1 /*
   2  * Copyright (C) 2000, 2001 Broadcom Corporation
   3  *
   4  * Copyright (C) 2002 MontaVista Software Inc.
   5  * Author: jsun@mvista.com or jsun@junsun.net
   6  *
   7  * This program is free software; you can redistribute  it and/or modify it
   8  * under  the terms of  the GNU General  Public License as published by the
   9  * Free Software Foundation;  either version 2 of the  License, or (at your
  10  * option) any later version.
  11  */
  12 #include <linux/bcd.h>
  13 #include <linux/types.h>
  14 #include <linux/time.h>
  15
  16 #include <asm/time.h>
  17 #include <asm/addrspace.h>
  18 #include <asm/io.h>
  19
  20 #include <asm/sibyte/sb1250.h>
  21 #include <asm/sibyte/sb1250_regs.h>
  22 #include <asm/sibyte/sb1250_smbus.h>
  23
  24
  25 /* Xicor 1241 definitions */
  26
  27 /*
  28  * Register bits
  29  */
  30
  31 #define X1241REG_SR_BAT 0x80            /* currently on battery power */
  32 #define X1241REG_SR_RWEL 0x04           /* r/w latch is enabled, can write RTC */
  33 #define X1241REG_SR_WEL 0x02            /* r/w latch is unlocked, can enable r/w now */
  34 #define X1241REG_SR_RTCF 0x01           /* clock failed */
  35 #define X1241REG_BL_BP2 0x80            /* block protect 2 */
  36 #define X1241REG_BL_BP1 0x40            /* block protect 1 */
  37 #define X1241REG_BL_BP0 0x20            /* block protect 0 */
  38 #define X1241REG_BL_WD1 0x10
  39 #define X1241REG_BL_WD0 0x08
  40 #define X1241REG_HR_MIL 0x80            /* military time format */
  41
  42 /*
  43  * Register numbers
  44  */
  45
  46 #define X1241REG_BL     0x10            /* block protect bits */
  47 #define X1241REG_INT    0x11            /*  */
  48 #define X1241REG_SC     0x30            /* Seconds */
  49 #define X1241REG_MN     0x31            /* Minutes */
  50 #define X1241REG_HR     0x32            /* Hours */
  51 #define X1241REG_DT     0x33            /* Day of month */
  52 #define X1241REG_MO     0x34            /* Month */
  53 #define X1241REG_YR     0x35            /* Year */
  54 #define X1241REG_DW     0x36            /* Day of Week */
  55 #define X1241REG_Y2K    0x37            /* Year 2K */
  56 #define X1241REG_SR     0x3F            /* Status register */
  57
  58 #define X1241_CCR_ADDRESS       0x6F
  59
  60 #define SMB_CSR(reg)    IOADDR(A_SMB_REGISTER(1, reg))
  61
  62 static int xicor_read(uint8_t addr)
  63 {
  64         while (__raw_readq(SMB_CSR(R_SMB_STATUS)) & M_SMB_BUSY)
  65                 ;
  66
  67         __raw_writeq((addr >> 8) & 0x7, SMB_CSR(R_SMB_CMD));
  68         __raw_writeq(addr & 0xff, SMB_CSR(R_SMB_DATA));
  69         __raw_writeq(V_SMB_ADDR(X1241_CCR_ADDRESS) | V_SMB_TT_WR2BYTE,
  70                      SMB_CSR(R_SMB_START));
  71
  72         while (__raw_readq(SMB_CSR(R_SMB_STATUS)) & M_SMB_BUSY)
  73                 ;
  74
  75         __raw_writeq(V_SMB_ADDR(X1241_CCR_ADDRESS) | V_SMB_TT_RD1BYTE,
  76                      SMB_CSR(R_SMB_START));
  77
  78         while (__raw_readq(SMB_CSR(R_SMB_STATUS)) & M_SMB_BUSY)
  79                 ;
  80
  81         if (__raw_readq(SMB_CSR(R_SMB_STATUS)) & M_SMB_ERROR) {
  82                 /* Clear error bit by writing a 1 */
  83                 __raw_writeq(M_SMB_ERROR, SMB_CSR(R_SMB_STATUS));
  84                 return -1;
  85         }
  86
  87         return __raw_readq(SMB_CSR(R_SMB_DATA)) & 0xff;
  88 }
  89
  90 static int xicor_write(uint8_t addr, int b)
  91 {
  92         while (__raw_readq(SMB_CSR(R_SMB_STATUS)) & M_SMB_BUSY)
  93                 ;
  94
  95         __raw_writeq(addr, SMB_CSR(R_SMB_CMD));
  96         __raw_writeq((addr & 0xff) | ((b & 0xff) << 8), SMB_CSR(R_SMB_DATA));
  97         __raw_writeq(V_SMB_ADDR(X1241_CCR_ADDRESS) | V_SMB_TT_WR3BYTE,
  98                      SMB_CSR(R_SMB_START));
  99
 100         while (__raw_readq(SMB_CSR(R_SMB_STATUS)) & M_SMB_BUSY)
 101                 ;
 102
 103         if (__raw_readq(SMB_CSR(R_SMB_STATUS)) & M_SMB_ERROR) {
 104                 /* Clear error bit by writing a 1 */
 105                 __raw_writeq(M_SMB_ERROR, SMB_CSR(R_SMB_STATUS));
 106                 return -1;
 107         } else {
 108                 return 0;
 109         }
 110 }
 111
 112 int xicor_set_time(unsigned long t)
 113 {
 114         struct rtc_time tm;
 115         int tmp;
 116         unsigned long flags;
 117
 118         rtc_time_to_tm(t, &tm);
 119         tm.tm_year += 1900;
 120
 121         spin_lock_irqsave(&rtc_lock, flags);
 122         /* unlock writes to the CCR */
 123         xicor_write(X1241REG_SR, X1241REG_SR_WEL);
 124         xicor_write(X1241REG_SR, X1241REG_SR_WEL | X1241REG_SR_RWEL);
 125
 126         /* trivial ones */
 127         tm.tm_sec = bin2bcd(tm.tm_sec);
 128         xicor_write(X1241REG_SC, tm.tm_sec);
 129
 130         tm.tm_min = bin2bcd(tm.tm_min);
 131         xicor_write(X1241REG_MN, tm.tm_min);
 132
 133         tm.tm_mday = bin2bcd(tm.tm_mday);
 134         xicor_write(X1241REG_DT, tm.tm_mday);
 135
 136         /* tm_mon starts from 0, *ick* */
 137         tm.tm_mon ++;
 138         tm.tm_mon = bin2bcd(tm.tm_mon);
 139         xicor_write(X1241REG_MO, tm.tm_mon);
 140
 141         /* year is split */
 142         tmp = tm.tm_year / 100;
 143         tm.tm_year %= 100;
 144         xicor_write(X1241REG_YR, tm.tm_year);
 145         xicor_write(X1241REG_Y2K, tmp);
 146
 147         /* hour is the most tricky one */
 148         tmp = xicor_read(X1241REG_HR);
 149         if (tmp & X1241REG_HR_MIL) {
 150                 /* 24 hour format */
 151                 tm.tm_hour = bin2bcd(tm.tm_hour);
 152                 tmp = (tmp & ~0x3f) | (tm.tm_hour & 0x3f);
 153         } else {
 154                 /* 12 hour format, with 0x2 for pm */
 155                 tmp = tmp & ~0x3f;
 156                 if (tm.tm_hour >= 12) {
 157                         tmp |= 0x20;
 158                         tm.tm_hour -= 12;
 159                 }
 160                 tm.tm_hour = bin2bcd(tm.tm_hour);
 161                 tmp |= tm.tm_hour;
 162         }
 163         xicor_write(X1241REG_HR, tmp);
 164
 165         xicor_write(X1241REG_SR, 0);
 166         spin_unlock_irqrestore(&rtc_lock, flags);
 167
 168         return 0;
 169 }
 170
 171 unsigned long xicor_get_time(void)
 172 {
 173         unsigned int year, mon, day, hour, min, sec, y2k;
 174         unsigned long flags;
 175
 176         spin_lock_irqsave(&rtc_lock, flags);
 177         sec = xicor_read(X1241REG_SC);
 178         min = xicor_read(X1241REG_MN);
 179         hour = xicor_read(X1241REG_HR);
 180
 181         if (hour & X1241REG_HR_MIL) {
 182                 hour &= 0x3f;
 183         } else {
 184                 if (hour & 0x20)
 185                         hour = (hour & 0xf) + 0x12;
 186         }
 187
 188         day = xicor_read(X1241REG_DT);
 189         mon = xicor_read(X1241REG_MO);
 190         year = xicor_read(X1241REG_YR);
 191         y2k = xicor_read(X1241REG_Y2K);
 192         spin_unlock_irqrestore(&rtc_lock, flags);
 193
 194         sec = bcd2bin(sec);
 195         min = bcd2bin(min);
 196         hour = bcd2bin(hour);
 197         day = bcd2bin(day);
 198         mon = bcd2bin(mon);
 199         year = bcd2bin(year);
 200         y2k = bcd2bin(y2k);
 201
 202         year += (y2k * 100);
 203
 204         return mktime(year, mon, day, hour, min, sec);
 205 }
 206
 207 int xicor_probe(void)
 208 {
 209         return xicor_read(X1241REG_SC) != -1;
 210 }