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
|
/*
* linux/arch/mips/dec/time.c
*
* Copyright (C) 1991, 1992, 1995 Linus Torvalds
* Copyright (C) 2000, 2003 Maciej W. Rozycki
*
* This file contains the time handling details for PC-style clocks as
* found in some MIPS systems.
*
*/
#include <linux/bcd.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/mc146818rtc.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/param.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/time.h>
#include <linux/types.h>
#include <asm/bootinfo.h>
#include <asm/cpu.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/mipsregs.h>
#include <asm/sections.h>
#include <asm/time.h>
#include <asm/dec/interrupts.h>
#include <asm/dec/ioasic.h>
#include <asm/dec/ioasic_addrs.h>
#include <asm/dec/machtype.h>
unsigned long read_persistent_clock(void)
{
unsigned int year, mon, day, hour, min, sec, real_year;
unsigned long flags;
spin_lock_irqsave(&rtc_lock, flags);
do {
sec = CMOS_READ(RTC_SECONDS);
min = CMOS_READ(RTC_MINUTES);
hour = CMOS_READ(RTC_HOURS);
day = CMOS_READ(RTC_DAY_OF_MONTH);
mon = CMOS_READ(RTC_MONTH);
year = CMOS_READ(RTC_YEAR);
/*
* The PROM will reset the year to either '72 or '73.
* Therefore we store the real year separately, in one
* of unused BBU RAM locations.
*/
real_year = CMOS_READ(RTC_DEC_YEAR);
} while (sec != CMOS_READ(RTC_SECONDS));
spin_unlock_irqrestore(&rtc_lock, flags);
if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
sec = BCD2BIN(sec);
min = BCD2BIN(min);
hour = BCD2BIN(hour);
day = BCD2BIN(day);
mon = BCD2BIN(mon);
year = BCD2BIN(year);
}
year += real_year - 72 + 2000;
return mktime(year, mon, day, hour, min, sec);
}
/*
* In order to set the CMOS clock precisely, rtc_mips_set_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 Dallas
* DS1287 data sheet for details.
*/
int rtc_mips_set_mmss(unsigned long nowtime)
{
int retval = 0;
int real_seconds, real_minutes, cmos_minutes;
unsigned char save_control, save_freq_select;
/* irq are locally disabled here */
spin_lock(&rtc_lock);
/* tell the clock it's being set */
save_control = CMOS_READ(RTC_CONTROL);
CMOS_WRITE((save_control | RTC_SET), RTC_CONTROL);
/* stop and reset prescaler */
save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
CMOS_WRITE((save_freq_select | RTC_DIV_RESET2), RTC_FREQ_SELECT);
cmos_minutes = CMOS_READ(RTC_MINUTES);
if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
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;
if (abs(real_minutes - cmos_minutes) < 30) {
if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
real_seconds = BIN2BCD(real_seconds);
real_minutes = BIN2BCD(real_minutes);
}
CMOS_WRITE(real_seconds, RTC_SECONDS);
CMOS_WRITE(real_minutes, RTC_MINUTES);
} else {
printk(KERN_WARNING
"set_rtc_mmss: can't update from %d to %d\n",
cmos_minutes, real_minutes);
retval = -1;
}
/* The following flags have to be released exactly in this order,
* otherwise the DS1287 will not reset the oscillator and will not
* update precisely 500 ms later. You won't find this mentioned
* in the Dallas Semiconductor data sheets, but who believes data
* sheets anyway ... -- Markus Kuhn
*/
CMOS_WRITE(save_control, RTC_CONTROL);
CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
spin_unlock(&rtc_lock);
return retval;
}
static int dec_timer_state(void)
{
return (CMOS_READ(RTC_REG_C) & RTC_PF) != 0;
}
static void dec_timer_ack(void)
{
CMOS_READ(RTC_REG_C); /* Ack the RTC interrupt. */
}
static cycle_t dec_ioasic_hpt_read(void)
{
/*
* The free-running counter is 32-bit which is good for about
* 2 minutes, 50 seconds at possible count rates of up to 25MHz.
*/
return ioasic_read(IO_REG_FCTR);
}
void __init plat_time_init(void)
{
mips_timer_ack = dec_timer_ack;
if (!cpu_has_counter && IOASIC)
/* For pre-R4k systems we use the I/O ASIC's counter. */
dec_ioasic_clocksource_init();
/* Set up the rate of periodic DS1287 interrupts. */
CMOS_WRITE(RTC_REF_CLCK_32KHZ | (16 - __ffs(HZ)), RTC_REG_A);
}
void __init plat_timer_setup(struct irqaction *irq)
{
setup_irq(dec_interrupt[DEC_IRQ_RTC], irq);
/* Enable periodic DS1287 interrupts. */
CMOS_WRITE(CMOS_READ(RTC_REG_B) | RTC_PIE, RTC_REG_B);
}
|
