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authorRussell King <rmk+kernel@arm.linux.org.uk>2009-12-24 07:52:44 -0500
committerRussell King <rmk+kernel@arm.linux.org.uk>2009-12-24 08:39:18 -0500
commit382b4480ff832e472d76c99f3f75fffb30e118c0 (patch)
treecaddb10180a24cda8b0ed280688dde14dcb7232e /arch/arm/mach-footbridge/time.c
parent6dc995a3da9adfa83d61ccf06aa1afa5f6ab764f (diff)
ARM: footbridge: trim down old ISA rtc setup
This fixes a "start_kernel(): bug: interrupts were enabled early". rtc_cmos now takes care of initializing the ISA RTC and reading the current time and date from it; there's no need to repeat that here, thereby causing interrupts to be enabled too early. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mach-footbridge/time.c')
-rw-r--r--arch/arm/mach-footbridge/time.c164
1 files changed, 0 insertions, 164 deletions
diff --git a/arch/arm/mach-footbridge/time.c b/arch/arm/mach-footbridge/time.c
deleted file mode 100644
index cd1b54ff9fe2..000000000000
--- a/arch/arm/mach-footbridge/time.c
+++ /dev/null
@@ -1,164 +0,0 @@
1/*
2 * arch/arm/mach-footbridge/include/mach/time.h
3 *
4 * Copyright (C) 1998 Russell King.
5 * Copyright (C) 1998 Phil Blundell
6 *
7 * CATS has a real-time clock, though the evaluation board doesn't.
8 *
9 * Changelog:
10 * 21-Mar-1998 RMK Created
11 * 27-Aug-1998 PJB CATS support
12 * 28-Dec-1998 APH Made leds optional
13 * 20-Jan-1999 RMK Started merge of EBSA285, CATS and NetWinder
14 * 16-Mar-1999 RMK More support for EBSA285-like machines with RTCs in
15 */
16
17#define RTC_PORT(x) (rtc_base+(x))
18#define RTC_ALWAYS_BCD 0
19
20#include <linux/timex.h>
21#include <linux/init.h>
22#include <linux/sched.h>
23#include <linux/mc146818rtc.h>
24#include <linux/bcd.h>
25#include <linux/io.h>
26
27#include <mach/hardware.h>
28
29#include <asm/mach/time.h>
30#include "common.h"
31
32static int rtc_base;
33
34static unsigned long __init get_isa_cmos_time(void)
35{
36 unsigned int year, mon, day, hour, min, sec;
37
38 // check to see if the RTC makes sense.....
39 if ((CMOS_READ(RTC_VALID) & RTC_VRT) == 0)
40 return mktime(1970, 1, 1, 0, 0, 0);
41
42 do {
43 sec = CMOS_READ(RTC_SECONDS);
44 min = CMOS_READ(RTC_MINUTES);
45 hour = CMOS_READ(RTC_HOURS);
46 day = CMOS_READ(RTC_DAY_OF_MONTH);
47 mon = CMOS_READ(RTC_MONTH);
48 year = CMOS_READ(RTC_YEAR);
49 } while (sec != CMOS_READ(RTC_SECONDS));
50
51 if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
52 sec = bcd2bin(sec);
53 min = bcd2bin(min);
54 hour = bcd2bin(hour);
55 day = bcd2bin(day);
56 mon = bcd2bin(mon);
57 year = bcd2bin(year);
58 }
59 if ((year += 1900) < 1970)
60 year += 100;
61 return mktime(year, mon, day, hour, min, sec);
62}
63
64static int set_isa_cmos_time(void)
65{
66 int retval = 0;
67 int real_seconds, real_minutes, cmos_minutes;
68 unsigned char save_control, save_freq_select;
69 unsigned long nowtime = xtime.tv_sec;
70
71 save_control = CMOS_READ(RTC_CONTROL); /* tell the clock it's being set */
72 CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL);
73
74 save_freq_select = CMOS_READ(RTC_FREQ_SELECT); /* stop and reset prescaler */
75 CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
76
77 cmos_minutes = CMOS_READ(RTC_MINUTES);
78 if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
79 cmos_minutes = bcd2bin(cmos_minutes);
80
81 /*
82 * since we're only adjusting minutes and seconds,
83 * don't interfere with hour overflow. This avoids
84 * messing with unknown time zones but requires your
85 * RTC not to be off by more than 15 minutes
86 */
87 real_seconds = nowtime % 60;
88 real_minutes = nowtime / 60;
89 if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1)
90 real_minutes += 30; /* correct for half hour time zone */
91 real_minutes %= 60;
92
93 if (abs(real_minutes - cmos_minutes) < 30) {
94 if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
95 real_seconds = bin2bcd(real_seconds);
96 real_minutes = bin2bcd(real_minutes);
97 }
98 CMOS_WRITE(real_seconds,RTC_SECONDS);
99 CMOS_WRITE(real_minutes,RTC_MINUTES);
100 } else
101 retval = -1;
102
103 /* The following flags have to be released exactly in this order,
104 * otherwise the DS12887 (popular MC146818A clone with integrated
105 * battery and quartz) will not reset the oscillator and will not
106 * update precisely 500 ms later. You won't find this mentioned in
107 * the Dallas Semiconductor data sheets, but who believes data
108 * sheets anyway ... -- Markus Kuhn
109 */
110 CMOS_WRITE(save_control, RTC_CONTROL);
111 CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
112
113 return retval;
114}
115
116void __init isa_rtc_init(void)
117{
118 if (machine_is_personal_server())
119 /*
120 * Add-in 21285s shouldn't access the RTC
121 */
122 rtc_base = 0;
123 else
124 rtc_base = 0x70;
125
126 if (rtc_base) {
127 int reg_d, reg_b;
128
129 /*
130 * Probe for the RTC.
131 */
132 reg_d = CMOS_READ(RTC_REG_D);
133
134 /*
135 * make sure the divider is set
136 */
137 CMOS_WRITE(RTC_REF_CLCK_32KHZ, RTC_REG_A);
138
139 /*
140 * Set control reg B
141 * (24 hour mode, update enabled)
142 */
143 reg_b = CMOS_READ(RTC_REG_B) & 0x7f;
144 reg_b |= 2;
145 CMOS_WRITE(reg_b, RTC_REG_B);
146
147 if ((CMOS_READ(RTC_REG_A) & 0x7f) == RTC_REF_CLCK_32KHZ &&
148 CMOS_READ(RTC_REG_B) == reg_b) {
149 struct timespec tv;
150
151 /*
152 * We have a RTC. Check the battery
153 */
154 if ((reg_d & 0x80) == 0)
155 printk(KERN_WARNING "RTC: *** warning: CMOS battery bad\n");
156
157 tv.tv_nsec = 0;
158 tv.tv_sec = get_isa_cmos_time();
159 do_settimeofday(&tv);
160 set_rtc = set_isa_cmos_time;
161 } else
162 rtc_base = 0;
163 }
164}
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