| Russell King | 382b4480 | 2009-12-24 12:52:44 +0000 | [diff] [blame] | 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 | } |