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
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
|
/*
* 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 <linux/bcd.h>
#include <linux/init.h>
#include <linux/time.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <asm/system.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>
static unsigned long long sec_bias = 0;
static unsigned int usec_bias = 0;
/* 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) (IOADDR(A_SMB_REGISTER(1, reg)))
static int xicor_read(uint8_t addr)
{
while (__raw_readq(SMB_CSR(R_SMB_STATUS)) & M_SMB_BUSY)
;
__raw_writeq((addr >> 8) & 0x7, SMB_CSR(R_SMB_CMD));
__raw_writeq(addr & 0xff, SMB_CSR(R_SMB_DATA));
__raw_writeq(V_SMB_ADDR(X1241_CCR_ADDRESS) | V_SMB_TT_WR2BYTE,
SMB_CSR(R_SMB_START));
while (__raw_readq(SMB_CSR(R_SMB_STATUS)) & M_SMB_BUSY)
;
__raw_writeq(V_SMB_ADDR(X1241_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 xicor_write(uint8_t addr, int b)
{
while (__raw_readq(SMB_CSR(R_SMB_STATUS)) & M_SMB_BUSY)
;
__raw_writeq(addr, SMB_CSR(R_SMB_CMD));
__raw_writeq((addr & 0xff) | ((b & 0xff) << 8), SMB_CSR(R_SMB_DATA));
__raw_writeq(V_SMB_ADDR(X1241_CCR_ADDRESS) | V_SMB_TT_WR3BYTE,
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;
} else {
return 0;
}
}
/*
* 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);
cmos_minutes = BCD2BIN(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) {
real_seconds = BIN2BCD(real_seconds);
real_minutes = BIN2BCD(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;
}
sec = BCD2BIN(sec);
min = BCD2BIN(min);
hour = BCD2BIN(hour);
day = xicor_read(X1241REG_DT);
mon = xicor_read(X1241REG_MO);
year = xicor_read(X1241REG_YR);
y2k = xicor_read(X1241REG_Y2K);
day = BCD2BIN(day);
mon = BCD2BIN(mon);
year = BCD2BIN(year);
y2k = BCD2BIN(y2k);
year += (y2k * 100);
return mktime(year, mon, day, hour, min, sec);
}
/*
* Bring up the timer at 100 Hz.
*/
void __init swarm_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? */
__raw_writeq(K_SMB_FREQ_400KHZ, SMB_CSR(R_SMB_FREQ));
__raw_writeq(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_seqlock_irqsave(&xtime_lock, flags);
xtime.tv_sec = get_swarm_time();
xtime.tv_nsec = 0;
write_sequnlock_irqrestore(&xtime_lock, flags);
}
}
|
