6cbdc8c535
Spelling fixes in arch/arm/. Signed-off-by: Simon Arlott <simon@fire.lp0.eu> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
89 lines
2.1 KiB
C
89 lines
2.1 KiB
C
/*
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* arch/arm/mach-ns9xxx/time.c
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*
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* Copyright (C) 2006 by Digi International Inc.
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* All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*/
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#include <linux/jiffies.h>
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#include <linux/interrupt.h>
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#include <linux/irq.h>
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#include <asm/arch-ns9xxx/regs-sys.h>
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#include <asm/arch-ns9xxx/clock.h>
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#include <asm/arch-ns9xxx/irqs.h>
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#include <asm/arch/system.h>
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#include "generic.h"
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#define TIMERCLOCKSELECT 64
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static u32 usecs_per_tick;
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static irqreturn_t
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ns9xxx_timer_interrupt(int irq, void *dev_id)
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{
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write_seqlock(&xtime_lock);
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timer_tick();
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write_sequnlock(&xtime_lock);
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return IRQ_HANDLED;
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}
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static unsigned long ns9xxx_timer_gettimeoffset(void)
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{
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/* return the microseconds which have passed since the last interrupt
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* was _serviced_. That is, if an interrupt is pending or the counter
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* reloads, return one period more. */
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u32 counter1 = SYS_TR(0);
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int pending = SYS_ISR & (1 << IRQ_TIMER0);
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u32 counter2 = SYS_TR(0);
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u32 elapsed;
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if (pending || counter2 > counter1)
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elapsed = 2 * SYS_TRC(0) - counter2;
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else
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elapsed = SYS_TRC(0) - counter1;
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return (elapsed * usecs_per_tick) >> 16;
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}
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static struct irqaction ns9xxx_timer_irq = {
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.name = "NS9xxx Timer Tick",
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.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
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.handler = ns9xxx_timer_interrupt,
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};
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static void __init ns9xxx_timer_init(void)
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{
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int tc;
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usecs_per_tick =
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SH_DIV(1000000 * TIMERCLOCKSELECT, ns9xxx_cpuclock(), 16);
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/* disable timer */
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if ((tc = SYS_TC(0)) & SYS_TCx_TEN)
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SYS_TC(0) = tc & ~SYS_TCx_TEN;
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SYS_TRC(0) = SH_DIV(ns9xxx_cpuclock(), (TIMERCLOCKSELECT * HZ), 0);
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REGSET(tc, SYS_TCx, TEN, EN);
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REGSET(tc, SYS_TCx, TLCS, DIV64); /* This must match TIMERCLOCKSELECT */
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REGSET(tc, SYS_TCx, INTS, EN);
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REGSET(tc, SYS_TCx, UDS, DOWN);
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REGSET(tc, SYS_TCx, TDBG, STOP);
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REGSET(tc, SYS_TCx, TSZ, 32);
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REGSET(tc, SYS_TCx, REN, EN);
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SYS_TC(0) = tc;
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setup_irq(IRQ_TIMER0, &ns9xxx_timer_irq);
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}
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struct sys_timer ns9xxx_timer = {
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.init = ns9xxx_timer_init,
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.offset = ns9xxx_timer_gettimeoffset,
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};
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