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/timex.h> 20#include <linux/init.h> 21#include <linux/interrupt.h> 22#include <linux/irq.h> 23#include <linux/sched.h> 24#include <linux/io.h> 25 26#include <mach/hardware.h> 27#include <asm/irq.h> 28#include <asm/leds.h> 29#include <asm/hardware/clps7111.h> 30 31#include <asm/mach/time.h> 32 33 34/* 35 * gettimeoffset() returns time since last timer tick, in usecs. 36 * 37 * 'LATCH' is hwclock ticks (see CLOCK_TICK_RATE in timex.h) per jiffy. 38 * 'tick' is usecs per jiffy. 39 */ 40static unsigned long clps711x_gettimeoffset(void) 41{ 42 unsigned long hwticks; 43 hwticks = LATCH - (clps_readl(TC2D) & 0xffff); /* since last underflow */ 44 return (hwticks * (tick_nsec / 1000)) / LATCH; 45} 46 47/* 48 * IRQ handler for the timer 49 */ 50static irqreturn_t 51p720t_timer_interrupt(int irq, void *dev_id) 52{ 53 timer_tick(); 54 return IRQ_HANDLED; 55} 56 57static struct irqaction clps711x_timer_irq = { 58 .name = "CLPS711x Timer Tick", 59 .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL, 60 .handler = p720t_timer_interrupt, 61}; 62 63static void __init clps711x_timer_init(void) 64{ 65 struct timespec tv; 66 unsigned int syscon; 67 68 syscon = clps_readl(SYSCON1); 69 syscon |= SYSCON1_TC2S | SYSCON1_TC2M; 70 clps_writel(syscon, SYSCON1); 71 72 clps_writel(LATCH-1, TC2D); /* 512kHz / 100Hz - 1 */ 73 74 setup_irq(IRQ_TC2OI, &clps711x_timer_irq); 75 76 tv.tv_nsec = 0; 77 tv.tv_sec = clps_readl(RTCDR); 78 do_settimeofday(&tv); 79} 80 81struct sys_timer clps711x_timer = { 82 .init = clps711x_timer_init, 83 .offset = clps711x_gettimeoffset, 84}; 85