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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2000, 2001 Broadcom Corporation
4 *
5 * Copyright (C) 2002 MontaVista Software Inc.
6 * Author: jsun@mvista.com or jsun@junsun.net
7 */
8#include <linux/bcd.h>
9#include <linux/types.h>
10#include <linux/time.h>
11
12#include <asm/time.h>
13#include <asm/addrspace.h>
14#include <asm/io.h>
15
16#include <asm/sibyte/sb1250.h>
17#include <asm/sibyte/sb1250_regs.h>
18#include <asm/sibyte/sb1250_smbus.h>
19
20
21/* Xicor 1241 definitions */
22
23/*
24 * Register bits
25 */
26
27#define X1241REG_SR_BAT 0x80 /* currently on battery power */
28#define X1241REG_SR_RWEL 0x04 /* r/w latch is enabled, can write RTC */
29#define X1241REG_SR_WEL 0x02 /* r/w latch is unlocked, can enable r/w now */
30#define X1241REG_SR_RTCF 0x01 /* clock failed */
31#define X1241REG_BL_BP2 0x80 /* block protect 2 */
32#define X1241REG_BL_BP1 0x40 /* block protect 1 */
33#define X1241REG_BL_BP0 0x20 /* block protect 0 */
34#define X1241REG_BL_WD1 0x10
35#define X1241REG_BL_WD0 0x08
36#define X1241REG_HR_MIL 0x80 /* military time format */
37
38/*
39 * Register numbers
40 */
41
42#define X1241REG_BL 0x10 /* block protect bits */
43#define X1241REG_INT 0x11 /* */
44#define X1241REG_SC 0x30 /* Seconds */
45#define X1241REG_MN 0x31 /* Minutes */
46#define X1241REG_HR 0x32 /* Hours */
47#define X1241REG_DT 0x33 /* Day of month */
48#define X1241REG_MO 0x34 /* Month */
49#define X1241REG_YR 0x35 /* Year */
50#define X1241REG_DW 0x36 /* Day of Week */
51#define X1241REG_Y2K 0x37 /* Year 2K */
52#define X1241REG_SR 0x3F /* Status register */
53
54#define X1241_CCR_ADDRESS 0x6F
55
56#define SMB_CSR(reg) IOADDR(A_SMB_REGISTER(1, reg))
57
58static int xicor_read(uint8_t addr)
59{
60 while (__raw_readq(SMB_CSR(R_SMB_STATUS)) & M_SMB_BUSY)
61 ;
62
63 __raw_writeq((addr >> 8) & 0x7, SMB_CSR(R_SMB_CMD));
64 __raw_writeq(addr & 0xff, SMB_CSR(R_SMB_DATA));
65 __raw_writeq(V_SMB_ADDR(X1241_CCR_ADDRESS) | V_SMB_TT_WR2BYTE,
66 SMB_CSR(R_SMB_START));
67
68 while (__raw_readq(SMB_CSR(R_SMB_STATUS)) & M_SMB_BUSY)
69 ;
70
71 __raw_writeq(V_SMB_ADDR(X1241_CCR_ADDRESS) | V_SMB_TT_RD1BYTE,
72 SMB_CSR(R_SMB_START));
73
74 while (__raw_readq(SMB_CSR(R_SMB_STATUS)) & M_SMB_BUSY)
75 ;
76
77 if (__raw_readq(SMB_CSR(R_SMB_STATUS)) & M_SMB_ERROR) {
78 /* Clear error bit by writing a 1 */
79 __raw_writeq(M_SMB_ERROR, SMB_CSR(R_SMB_STATUS));
80 return -1;
81 }
82
83 return __raw_readq(SMB_CSR(R_SMB_DATA)) & 0xff;
84}
85
86static int xicor_write(uint8_t addr, int b)
87{
88 while (__raw_readq(SMB_CSR(R_SMB_STATUS)) & M_SMB_BUSY)
89 ;
90
91 __raw_writeq(addr, SMB_CSR(R_SMB_CMD));
92 __raw_writeq((addr & 0xff) | ((b & 0xff) << 8), SMB_CSR(R_SMB_DATA));
93 __raw_writeq(V_SMB_ADDR(X1241_CCR_ADDRESS) | V_SMB_TT_WR3BYTE,
94 SMB_CSR(R_SMB_START));
95
96 while (__raw_readq(SMB_CSR(R_SMB_STATUS)) & M_SMB_BUSY)
97 ;
98
99 if (__raw_readq(SMB_CSR(R_SMB_STATUS)) & M_SMB_ERROR) {
100 /* Clear error bit by writing a 1 */
101 __raw_writeq(M_SMB_ERROR, SMB_CSR(R_SMB_STATUS));
102 return -1;
103 } else {
104 return 0;
105 }
106}
107
108int xicor_set_time(time64_t t)
109{
110 struct rtc_time tm;
111 int tmp;
112 unsigned long flags;
113
114 rtc_time64_to_tm(t, &tm);
115 tm.tm_year += 1900;
116
117 spin_lock_irqsave(&rtc_lock, flags);
118 /* unlock writes to the CCR */
119 xicor_write(X1241REG_SR, X1241REG_SR_WEL);
120 xicor_write(X1241REG_SR, X1241REG_SR_WEL | X1241REG_SR_RWEL);
121
122 /* trivial ones */
123 tm.tm_sec = bin2bcd(tm.tm_sec);
124 xicor_write(X1241REG_SC, tm.tm_sec);
125
126 tm.tm_min = bin2bcd(tm.tm_min);
127 xicor_write(X1241REG_MN, tm.tm_min);
128
129 tm.tm_mday = bin2bcd(tm.tm_mday);
130 xicor_write(X1241REG_DT, tm.tm_mday);
131
132 /* tm_mon starts from 0, *ick* */
133 tm.tm_mon ++;
134 tm.tm_mon = bin2bcd(tm.tm_mon);
135 xicor_write(X1241REG_MO, tm.tm_mon);
136
137 /* year is split */
138 tmp = tm.tm_year / 100;
139 tm.tm_year %= 100;
140 xicor_write(X1241REG_YR, tm.tm_year);
141 xicor_write(X1241REG_Y2K, tmp);
142
143 /* hour is the most tricky one */
144 tmp = xicor_read(X1241REG_HR);
145 if (tmp & X1241REG_HR_MIL) {
146 /* 24 hour format */
147 tm.tm_hour = bin2bcd(tm.tm_hour);
148 tmp = (tmp & ~0x3f) | (tm.tm_hour & 0x3f);
149 } else {
150 /* 12 hour format, with 0x2 for pm */
151 tmp = tmp & ~0x3f;
152 if (tm.tm_hour >= 12) {
153 tmp |= 0x20;
154 tm.tm_hour -= 12;
155 }
156 tm.tm_hour = bin2bcd(tm.tm_hour);
157 tmp |= tm.tm_hour;
158 }
159 xicor_write(X1241REG_HR, tmp);
160
161 xicor_write(X1241REG_SR, 0);
162 spin_unlock_irqrestore(&rtc_lock, flags);
163
164 return 0;
165}
166
167time64_t xicor_get_time(void)
168{
169 unsigned int year, mon, day, hour, min, sec, y2k;
170 unsigned long flags;
171
172 spin_lock_irqsave(&rtc_lock, flags);
173 sec = xicor_read(X1241REG_SC);
174 min = xicor_read(X1241REG_MN);
175 hour = xicor_read(X1241REG_HR);
176
177 if (hour & X1241REG_HR_MIL) {
178 hour &= 0x3f;
179 } else {
180 if (hour & 0x20)
181 hour = (hour & 0xf) + 0x12;
182 }
183
184 day = xicor_read(X1241REG_DT);
185 mon = xicor_read(X1241REG_MO);
186 year = xicor_read(X1241REG_YR);
187 y2k = xicor_read(X1241REG_Y2K);
188 spin_unlock_irqrestore(&rtc_lock, flags);
189
190 sec = bcd2bin(sec);
191 min = bcd2bin(min);
192 hour = bcd2bin(hour);
193 day = bcd2bin(day);
194 mon = bcd2bin(mon);
195 year = bcd2bin(year);
196 y2k = bcd2bin(y2k);
197
198 year += (y2k * 100);
199
200 return mktime64(year, mon, day, hour, min, sec);
201}
202
203int xicor_probe(void)
204{
205 return xicor_read(X1241REG_SC) != -1;
206}