File: [Development] / linux-2.6-xfs / arch / mips / gt64120 / wrppmc / time.c (download)
Revision 1.2, Mon Dec 3 16:26:37 2007 UTC (9 years, 10 months ago) by lachlan.longdrop.melbourne.sgi.com
Branch: MAIN
CVS Tags: HEAD Changes since 1.1: +3 -16
lines
Merge up to 2.6.24-rc3
Merge of 2.6.x-xfs-melb:linux:30183b by kenmcd.
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/*
* time.c: MIPS CPU Count/Compare timer hookup
*
* Author: Mark.Zhan, <rongkai.zhan@windriver.com>
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1996, 1997, 2004 by Ralf Baechle (ralf@linux-mips.org)
* Copyright (C) 2006, Wind River System Inc.
*/
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <asm/gt64120.h>
#include <asm/time.h>
#define WRPPMC_CPU_CLK_FREQ 40000000 /* 40MHZ */
/*
* Estimate CPU frequency. Sets mips_hpt_frequency as a side-effect
*
* NOTE: We disable all GT64120 timers, and use MIPS processor internal
* timer as the source of kernel clock tick.
*/
void __init plat_time_init(void)
{
/* Disable GT64120 timers */
GT_WRITE(GT_TC_CONTROL_OFS, 0x00);
GT_WRITE(GT_TC0_OFS, 0x00);
GT_WRITE(GT_TC1_OFS, 0x00);
GT_WRITE(GT_TC2_OFS, 0x00);
GT_WRITE(GT_TC3_OFS, 0x00);
/* Use MIPS compare/count internal timer */
mips_hpt_frequency = WRPPMC_CPU_CLK_FREQ;
}