3945ca0f84
The recent changes to the old ColdFire interrupt controller code means we no longer need to manually unmask the timer interrupt. That is now done in the interrupt controller code proper. Signed-off-by: Greg Ungerer <gerg@uclinux.org>
175 lines
4.7 KiB
C
175 lines
4.7 KiB
C
/***************************************************************************/
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/*
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* timers.c -- generic ColdFire hardware timer support.
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*
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* Copyright (C) 1999-2008, Greg Ungerer <gerg@snapgear.com>
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*/
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/***************************************************************************/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/sched.h>
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#include <linux/interrupt.h>
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#include <linux/irq.h>
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#include <linux/profile.h>
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#include <linux/clocksource.h>
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#include <asm/io.h>
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#include <asm/traps.h>
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#include <asm/machdep.h>
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#include <asm/coldfire.h>
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#include <asm/mcftimer.h>
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#include <asm/mcfsim.h>
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/***************************************************************************/
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/*
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* By default use timer1 as the system clock timer.
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*/
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#define FREQ (MCF_BUSCLK / 16)
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#define TA(a) (MCF_MBAR + MCFTIMER_BASE1 + (a))
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/*
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* These provide the underlying interrupt vector support.
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* Unfortunately it is a little different on each ColdFire.
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*/
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void coldfire_profile_init(void);
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#if defined(CONFIG_M532x)
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#define __raw_readtrr __raw_readl
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#define __raw_writetrr __raw_writel
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#else
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#define __raw_readtrr __raw_readw
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#define __raw_writetrr __raw_writew
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#endif
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static u32 mcftmr_cycles_per_jiffy;
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static u32 mcftmr_cnt;
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/***************************************************************************/
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static irqreturn_t mcftmr_tick(int irq, void *dummy)
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{
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/* Reset the ColdFire timer */
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__raw_writeb(MCFTIMER_TER_CAP | MCFTIMER_TER_REF, TA(MCFTIMER_TER));
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mcftmr_cnt += mcftmr_cycles_per_jiffy;
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return arch_timer_interrupt(irq, dummy);
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}
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/***************************************************************************/
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static struct irqaction mcftmr_timer_irq = {
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.name = "timer",
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.flags = IRQF_DISABLED | IRQF_TIMER,
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.handler = mcftmr_tick,
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};
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/***************************************************************************/
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static cycle_t mcftmr_read_clk(struct clocksource *cs)
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{
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unsigned long flags;
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u32 cycles;
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u16 tcn;
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local_irq_save(flags);
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tcn = __raw_readw(TA(MCFTIMER_TCN));
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cycles = mcftmr_cnt;
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local_irq_restore(flags);
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return cycles + tcn;
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}
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/***************************************************************************/
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static struct clocksource mcftmr_clk = {
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.name = "tmr",
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.rating = 250,
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.read = mcftmr_read_clk,
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.shift = 20,
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.mask = CLOCKSOURCE_MASK(32),
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.flags = CLOCK_SOURCE_IS_CONTINUOUS,
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};
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/***************************************************************************/
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void hw_timer_init(void)
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{
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__raw_writew(MCFTIMER_TMR_DISABLE, TA(MCFTIMER_TMR));
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mcftmr_cycles_per_jiffy = FREQ / HZ;
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/*
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* The coldfire timer runs from 0 to TRR included, then 0
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* again and so on. It counts thus actually TRR + 1 steps
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* for 1 tick, not TRR. So if you want n cycles,
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* initialize TRR with n - 1.
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*/
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__raw_writetrr(mcftmr_cycles_per_jiffy - 1, TA(MCFTIMER_TRR));
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__raw_writew(MCFTIMER_TMR_ENORI | MCFTIMER_TMR_CLK16 |
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MCFTIMER_TMR_RESTART | MCFTIMER_TMR_ENABLE, TA(MCFTIMER_TMR));
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mcftmr_clk.mult = clocksource_hz2mult(FREQ, mcftmr_clk.shift);
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clocksource_register(&mcftmr_clk);
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setup_irq(MCF_IRQ_TIMER, &mcftmr_timer_irq);
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#ifdef CONFIG_HIGHPROFILE
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coldfire_profile_init();
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#endif
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}
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/***************************************************************************/
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#ifdef CONFIG_HIGHPROFILE
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/***************************************************************************/
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/*
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* By default use timer2 as the profiler clock timer.
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*/
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#define PA(a) (MCF_MBAR + MCFTIMER_BASE2 + (a))
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/*
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* Choose a reasonably fast profile timer. Make it an odd value to
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* try and get good coverage of kernel operations.
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*/
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#define PROFILEHZ 1013
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/*
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* Use the other timer to provide high accuracy profiling info.
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*/
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irqreturn_t coldfire_profile_tick(int irq, void *dummy)
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{
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/* Reset ColdFire timer2 */
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__raw_writeb(MCFTIMER_TER_CAP | MCFTIMER_TER_REF, PA(MCFTIMER_TER));
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if (current->pid)
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profile_tick(CPU_PROFILING);
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return IRQ_HANDLED;
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}
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/***************************************************************************/
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static struct irqaction coldfire_profile_irq = {
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.name = "profile timer",
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.flags = IRQF_DISABLED | IRQF_TIMER,
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.handler = coldfire_profile_tick,
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};
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void coldfire_profile_init(void)
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{
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printk(KERN_INFO "PROFILE: lodging TIMER2 @ %dHz as profile timer\n",
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PROFILEHZ);
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/* Set up TIMER 2 as high speed profile clock */
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__raw_writew(MCFTIMER_TMR_DISABLE, PA(MCFTIMER_TMR));
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__raw_writetrr(((MCF_BUSCLK / 16) / PROFILEHZ), PA(MCFTIMER_TRR));
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__raw_writew(MCFTIMER_TMR_ENORI | MCFTIMER_TMR_CLK16 |
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MCFTIMER_TMR_RESTART | MCFTIMER_TMR_ENABLE, PA(MCFTIMER_TMR));
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setup_irq(MCF_IRQ_PROFILER, &coldfire_profile_irq);
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}
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/***************************************************************************/
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#endif /* CONFIG_HIGHPROFILE */
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/***************************************************************************/
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