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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 | // SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright (C) 2000, 2001 Broadcom Corporation * * Copyright (C) 2002 MontaVista Software Inc. * Author: jsun@mvista.com or jsun@junsun.net */ #include <linux/bcd.h> #include <linux/types.h> #include <linux/time.h> #include <asm/time.h> #include <asm/addrspace.h> #include <asm/io.h> #include <asm/sibyte/sb1250.h> #include <asm/sibyte/sb1250_regs.h> #include <asm/sibyte/sb1250_smbus.h> /* M41T81 definitions */ /* * Register bits */ #define M41T81REG_SC_ST 0x80 /* stop bit */ #define M41T81REG_HR_CB 0x40 /* century bit */ #define M41T81REG_HR_CEB 0x80 /* century enable bit */ #define M41T81REG_CTL_S 0x20 /* sign bit */ #define M41T81REG_CTL_FT 0x40 /* frequency test bit */ #define M41T81REG_CTL_OUT 0x80 /* output level */ #define M41T81REG_WD_RB0 0x01 /* watchdog resolution bit 0 */ #define M41T81REG_WD_RB1 0x02 /* watchdog resolution bit 1 */ #define M41T81REG_WD_BMB0 0x04 /* watchdog multiplier bit 0 */ #define M41T81REG_WD_BMB1 0x08 /* watchdog multiplier bit 1 */ #define M41T81REG_WD_BMB2 0x10 /* watchdog multiplier bit 2 */ #define M41T81REG_WD_BMB3 0x20 /* watchdog multiplier bit 3 */ #define M41T81REG_WD_BMB4 0x40 /* watchdog multiplier bit 4 */ #define M41T81REG_AMO_ABE 0x20 /* alarm in "battery back-up mode" enable bit */ #define M41T81REG_AMO_SQWE 0x40 /* square wave enable */ #define M41T81REG_AMO_AFE 0x80 /* alarm flag enable flag */ #define M41T81REG_ADT_RPT5 0x40 /* alarm repeat mode bit 5 */ #define M41T81REG_ADT_RPT4 0x80 /* alarm repeat mode bit 4 */ #define M41T81REG_AHR_RPT3 0x80 /* alarm repeat mode bit 3 */ #define M41T81REG_AHR_HT 0x40 /* halt update bit */ #define M41T81REG_AMN_RPT2 0x80 /* alarm repeat mode bit 2 */ #define M41T81REG_ASC_RPT1 0x80 /* alarm repeat mode bit 1 */ #define M41T81REG_FLG_AF 0x40 /* alarm flag (read only) */ #define M41T81REG_FLG_WDF 0x80 /* watchdog flag (read only) */ #define M41T81REG_SQW_RS0 0x10 /* sqw frequency bit 0 */ #define M41T81REG_SQW_RS1 0x20 /* sqw frequency bit 1 */ #define M41T81REG_SQW_RS2 0x40 /* sqw frequency bit 2 */ #define M41T81REG_SQW_RS3 0x80 /* sqw frequency bit 3 */ /* * Register numbers */ #define M41T81REG_TSC 0x00 /* tenths/hundredths of second */ #define M41T81REG_SC 0x01 /* seconds */ #define M41T81REG_MN 0x02 /* minute */ #define M41T81REG_HR 0x03 /* hour/century */ #define M41T81REG_DY 0x04 /* day of week */ #define M41T81REG_DT 0x05 /* date of month */ #define M41T81REG_MO 0x06 /* month */ #define M41T81REG_YR 0x07 /* year */ #define M41T81REG_CTL 0x08 /* control */ #define M41T81REG_WD 0x09 /* watchdog */ #define M41T81REG_AMO 0x0A /* alarm: month */ #define M41T81REG_ADT 0x0B /* alarm: date */ #define M41T81REG_AHR 0x0C /* alarm: hour */ #define M41T81REG_AMN 0x0D /* alarm: minute */ #define M41T81REG_ASC 0x0E /* alarm: second */ #define M41T81REG_FLG 0x0F /* flags */ #define M41T81REG_SQW 0x13 /* square wave register */ #define M41T81_CCR_ADDRESS 0x68 #define SMB_CSR(reg) IOADDR(A_SMB_REGISTER(1, reg)) static int m41t81_read(uint8_t addr) { while (__raw_readq(SMB_CSR(R_SMB_STATUS)) & M_SMB_BUSY) ; __raw_writeq(addr & 0xff, SMB_CSR(R_SMB_CMD)); __raw_writeq(V_SMB_ADDR(M41T81_CCR_ADDRESS) | V_SMB_TT_WR1BYTE, SMB_CSR(R_SMB_START)); while (__raw_readq(SMB_CSR(R_SMB_STATUS)) & M_SMB_BUSY) ; __raw_writeq(V_SMB_ADDR(M41T81_CCR_ADDRESS) | V_SMB_TT_RD1BYTE, SMB_CSR(R_SMB_START)); while (__raw_readq(SMB_CSR(R_SMB_STATUS)) & M_SMB_BUSY) ; if (__raw_readq(SMB_CSR(R_SMB_STATUS)) & M_SMB_ERROR) { /* Clear error bit by writing a 1 */ __raw_writeq(M_SMB_ERROR, SMB_CSR(R_SMB_STATUS)); return -1; } return __raw_readq(SMB_CSR(R_SMB_DATA)) & 0xff; } static int m41t81_write(uint8_t addr, int b) { while (__raw_readq(SMB_CSR(R_SMB_STATUS)) & M_SMB_BUSY) ; __raw_writeq(addr & 0xff, SMB_CSR(R_SMB_CMD)); __raw_writeq(b & 0xff, SMB_CSR(R_SMB_DATA)); __raw_writeq(V_SMB_ADDR(M41T81_CCR_ADDRESS) | V_SMB_TT_WR2BYTE, SMB_CSR(R_SMB_START)); while (__raw_readq(SMB_CSR(R_SMB_STATUS)) & M_SMB_BUSY) ; if (__raw_readq(SMB_CSR(R_SMB_STATUS)) & M_SMB_ERROR) { /* Clear error bit by writing a 1 */ __raw_writeq(M_SMB_ERROR, SMB_CSR(R_SMB_STATUS)); return -1; } /* read the same byte again to make sure it is written */ __raw_writeq(V_SMB_ADDR(M41T81_CCR_ADDRESS) | V_SMB_TT_RD1BYTE, SMB_CSR(R_SMB_START)); while (__raw_readq(SMB_CSR(R_SMB_STATUS)) & M_SMB_BUSY) ; return 0; } int m41t81_set_time(time64_t t) { struct rtc_time tm; unsigned long flags; /* Note we don't care about the century */ rtc_time64_to_tm(t, &tm); /* * Note the write order matters as it ensures the correctness. * When we write sec, 10th sec is clear. It is reasonable to * believe we should finish writing min within a second. */ spin_lock_irqsave(&rtc_lock, flags); tm.tm_sec = bin2bcd(tm.tm_sec); m41t81_write(M41T81REG_SC, tm.tm_sec); tm.tm_min = bin2bcd(tm.tm_min); m41t81_write(M41T81REG_MN, tm.tm_min); tm.tm_hour = bin2bcd(tm.tm_hour); tm.tm_hour = (tm.tm_hour & 0x3f) | (m41t81_read(M41T81REG_HR) & 0xc0); m41t81_write(M41T81REG_HR, tm.tm_hour); /* tm_wday starts from 0 to 6 */ if (tm.tm_wday == 0) tm.tm_wday = 7; tm.tm_wday = bin2bcd(tm.tm_wday); m41t81_write(M41T81REG_DY, tm.tm_wday); tm.tm_mday = bin2bcd(tm.tm_mday); m41t81_write(M41T81REG_DT, tm.tm_mday); /* tm_mon starts from 0, *ick* */ tm.tm_mon ++; tm.tm_mon = bin2bcd(tm.tm_mon); m41t81_write(M41T81REG_MO, tm.tm_mon); /* we don't do century, everything is beyond 2000 */ tm.tm_year %= 100; tm.tm_year = bin2bcd(tm.tm_year); m41t81_write(M41T81REG_YR, tm.tm_year); spin_unlock_irqrestore(&rtc_lock, flags); return 0; } time64_t m41t81_get_time(void) { unsigned int year, mon, day, hour, min, sec; unsigned long flags; /* * min is valid if two reads of sec are the same. */ for (;;) { spin_lock_irqsave(&rtc_lock, flags); sec = m41t81_read(M41T81REG_SC); min = m41t81_read(M41T81REG_MN); if (sec == m41t81_read(M41T81REG_SC)) break; spin_unlock_irqrestore(&rtc_lock, flags); } hour = m41t81_read(M41T81REG_HR) & 0x3f; day = m41t81_read(M41T81REG_DT); mon = m41t81_read(M41T81REG_MO); year = m41t81_read(M41T81REG_YR); spin_unlock_irqrestore(&rtc_lock, flags); sec = bcd2bin(sec); min = bcd2bin(min); hour = bcd2bin(hour); day = bcd2bin(day); mon = bcd2bin(mon); year = bcd2bin(year); year += 2000; return mktime64(year, mon, day, hour, min, sec); } int m41t81_probe(void) { unsigned int tmp; /* enable chip if it is not enabled yet */ tmp = m41t81_read(M41T81REG_SC); m41t81_write(M41T81REG_SC, tmp & 0x7f); return m41t81_read(M41T81REG_SC) != -1; } |