1/* 2 * linux/arch/arm/mach-clps711x/time.c 3 * 4 * Copyright (C) 2001 Deep Blue Solutions Ltd. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 18 */ 19#include <linux/sched.h> 20#include <linux/init.h> 21 22#include <asm/hardware.h> 23#include <asm/io.h> 24#include <asm/hardware/clps7111.h> 25 26extern unsigned long (*gettimeoffset)(void); 27 28/* 29 * gettimeoffset() returns time since last timer tick, in usecs. 30 * 31 * 'LATCH' is hwclock ticks (see CLOCK_TICK_RATE in timex.h) per jiffy. 32 * 'tick' is usecs per jiffy. 33 */ 34static unsigned long clps711x_gettimeoffset(void) 35{ 36 unsigned long hwticks; 37 hwticks = LATCH - (clps_readl(TC2D) & 0xffff); /* since last underflow */ 38 return (hwticks * tick) / LATCH; 39} 40 41void __init clps711x_setup_timer(void) 42{ 43 unsigned int syscon; 44 45 gettimeoffset = clps711x_gettimeoffset; 46 47 syscon = clps_readl(SYSCON1); 48 syscon |= SYSCON1_TC2S | SYSCON1_TC2M; 49 clps_writel(syscon, SYSCON1); 50 51 clps_writel(LATCH-1, TC2D); /* 512kHz / 100Hz - 1 */ 52 53 xtime.tv_sec = clps_readl(RTCDR); 54} 55