arch/mn10300/kernel/rtc.c

   1 /* MN10300 RTC management
   2  *
   3  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public Licence
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the Licence, or (at your option) any later version.
  10  */
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/mc146818rtc.h>
  15 #include <linux/ioport.h>
  16 #include <linux/platform_device.h>
  17
  18 #include <asm/rtc-regs.h>
  19 #include <asm/rtc.h>
  20
  21 DEFINE_SPINLOCK(rtc_lock);
  22 EXPORT_SYMBOL(rtc_lock);
  23
  24 static const __initdata struct resource res[] = {
  25         DEFINE_RES_IO(RTC_PORT(0), RTC_IO_EXTENT),
  26         DEFINE_RES_IRQ(RTC_IRQ),
  27 };
  28
  29 /*
  30  * calibrate the TSC clock against the RTC
  31  */
  32 void __init calibrate_clock(void)
  33 {
  34         unsigned char status;
  35
  36         /* make sure the RTC is running and is set to operate in 24hr mode */
  37         status = RTSRC;
  38         RTCRB |= RTCRB_SET;
  39         RTCRB |= RTCRB_TM_24HR;
  40         RTCRB &= ~RTCRB_DM_BINARY;
  41         RTCRA |= RTCRA_DVR;
  42         RTCRA &= ~RTCRA_DVR;
  43         RTCRB &= ~RTCRB_SET;
  44
  45         platform_device_register_simple("rtc_cmos", -1, res, ARRAY_SIZE(res));
  46 }