86 lines
2.2 KiB
C
86 lines
2.2 KiB
C
/*
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* linux/arch/arm/mach-clps711x/time.c
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*
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* Copyright (C) 2001 Deep Blue Solutions Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/timex.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/sched.h>
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#include <asm/hardware.h>
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#include <asm/irq.h>
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#include <asm/leds.h>
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#include <asm/io.h>
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#include <asm/hardware/clps7111.h>
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#include <asm/mach/time.h>
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/*
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* gettimeoffset() returns time since last timer tick, in usecs.
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*
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* 'LATCH' is hwclock ticks (see CLOCK_TICK_RATE in timex.h) per jiffy.
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* 'tick' is usecs per jiffy.
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*/
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static unsigned long clps711x_gettimeoffset(void)
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{
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unsigned long hwticks;
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hwticks = LATCH - (clps_readl(TC2D) & 0xffff); /* since last underflow */
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return (hwticks * (tick_nsec / 1000)) / LATCH;
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}
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/*
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* IRQ handler for the timer
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*/
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static irqreturn_t
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p720t_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
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{
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write_seqlock(&xtime_lock);
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timer_tick(regs);
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write_sequnlock(&xtime_lock);
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return IRQ_HANDLED;
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}
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static struct irqaction clps711x_timer_irq = {
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.name = "CLPS711x Timer Tick",
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.flags = SA_INTERRUPT | SA_TIMER,
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.handler = p720t_timer_interrupt,
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};
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static void __init clps711x_timer_init(void)
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{
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struct timespec tv;
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unsigned int syscon;
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syscon = clps_readl(SYSCON1);
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syscon |= SYSCON1_TC2S | SYSCON1_TC2M;
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clps_writel(syscon, SYSCON1);
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clps_writel(LATCH-1, TC2D); /* 512kHz / 100Hz - 1 */
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setup_irq(IRQ_TC2OI, &clps711x_timer_irq);
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tv.tv_nsec = 0;
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tv.tv_sec = clps_readl(RTCDR);
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do_settimeofday(&tv);
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}
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struct sys_timer clps711x_timer = {
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.init = clps711x_timer_init,
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.offset = clps711x_gettimeoffset,
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};
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