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 */ calibrate_clock(void)32void __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 } 47