Logo Search packages:      
Sourcecode: linux version File versions  Download package

isa-rtc.c

/*
 *  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");
      }
}

Generated by  Doxygen 1.6.0   Back to index