Commit | Line | Data |
---|---|---|
382b4480 RK |
1 | /* |
2 | * arch/arm/mach-footbridge/isa-rtc.c | |
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) (0x70+(x)) | |
18 | #define RTC_ALWAYS_BCD 0 | |
19 | ||
20 | #include <linux/init.h> | |
21 | #include <linux/mc146818rtc.h> | |
22 | #include <linux/bcd.h> | |
23 | #include <linux/io.h> | |
24 | ||
25 | #include "common.h" | |
26 | ||
27 | void __init isa_rtc_init(void) | |
28 | { | |
29 | int reg_d, reg_b; | |
30 | ||
31 | /* | |
32 | * Probe for the RTC. | |
33 | */ | |
34 | reg_d = CMOS_READ(RTC_REG_D); | |
35 | ||
36 | /* | |
37 | * make sure the divider is set | |
38 | */ | |
39 | CMOS_WRITE(RTC_REF_CLCK_32KHZ, RTC_REG_A); | |
40 | ||
41 | /* | |
42 | * Set control reg B | |
43 | * (24 hour mode, update enabled) | |
44 | */ | |
45 | reg_b = CMOS_READ(RTC_REG_B) & 0x7f; | |
46 | reg_b |= 2; | |
47 | CMOS_WRITE(reg_b, RTC_REG_B); | |
48 | ||
49 | if ((CMOS_READ(RTC_REG_A) & 0x7f) == RTC_REF_CLCK_32KHZ && | |
50 | CMOS_READ(RTC_REG_B) == reg_b) { | |
51 | /* | |
52 | * We have a RTC. Check the battery | |
53 | */ | |
54 | if ((reg_d & 0x80) == 0) | |
55 | printk(KERN_WARNING "RTC: *** warning: CMOS battery bad\n"); | |
56 | } | |
57 | } |