diff options
Diffstat (limited to 'kernel/arch/arm/mach-footbridge/isa-rtc.c')
| -rw-r--r-- | kernel/arch/arm/mach-footbridge/isa-rtc.c | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/kernel/arch/arm/mach-footbridge/isa-rtc.c b/kernel/arch/arm/mach-footbridge/isa-rtc.c new file mode 100644 index 000000000..07fde4051 --- /dev/null +++ b/kernel/arch/arm/mach-footbridge/isa-rtc.c @@ -0,0 +1,57 @@ +/* + * arch/arm/mach-footbridge/isa-rtc.c + * + * Copyright (C) 1998 Russell King. + * Copyright (C) 1998 Phil Blundell + * + * CATS has a real-time clock, though the evaluation board doesn't. + * + * Changelog: + * 21-Mar-1998 RMK Created + * 27-Aug-1998 PJB CATS support + * 28-Dec-1998 APH Made leds optional + * 20-Jan-1999 RMK Started merge of EBSA285, CATS and NetWinder + * 16-Mar-1999 RMK More support for EBSA285-like machines with RTCs in + */ + +#define RTC_PORT(x) (0x70+(x)) +#define RTC_ALWAYS_BCD 0 + +#include <linux/init.h> +#include <linux/mc146818rtc.h> +#include <linux/bcd.h> +#include <linux/io.h> + +#include "common.h" + +void __init isa_rtc_init(void) +{ + int reg_d, reg_b; + + /* + * Probe for the RTC. + */ + reg_d = CMOS_READ(RTC_REG_D); + + /* + * make sure the divider is set + */ + CMOS_WRITE(RTC_REF_CLCK_32KHZ, RTC_REG_A); + + /* + * Set control reg B + * (24 hour mode, update enabled) + */ + reg_b = CMOS_READ(RTC_REG_B) & 0x7f; + reg_b |= 2; + CMOS_WRITE(reg_b, RTC_REG_B); + + if ((CMOS_READ(RTC_REG_A) & 0x7f) == RTC_REF_CLCK_32KHZ && + CMOS_READ(RTC_REG_B) == reg_b) { + /* + * We have a RTC. Check the battery + */ + if ((reg_d & 0x80) == 0) + printk(KERN_WARNING "RTC: *** warning: CMOS battery bad\n"); + } +} |