196 строки
5.3 KiB
C
196 строки
5.3 KiB
C
/***************************************************************************/
|
|
|
|
/*
|
|
* timers.c -- generic ColdFire hardware timer support.
|
|
*
|
|
* Copyright (C) 1999-2008, Greg Ungerer <gerg@snapgear.com>
|
|
*/
|
|
|
|
/***************************************************************************/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/init.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/irq.h>
|
|
#include <linux/profile.h>
|
|
#include <linux/clocksource.h>
|
|
#include <asm/io.h>
|
|
#include <asm/traps.h>
|
|
#include <asm/machdep.h>
|
|
#include <asm/coldfire.h>
|
|
#include <asm/mcftimer.h>
|
|
#include <asm/mcfsim.h>
|
|
|
|
/***************************************************************************/
|
|
|
|
/*
|
|
* By default use timer1 as the system clock timer.
|
|
*/
|
|
#define FREQ (MCF_BUSCLK / 16)
|
|
#define TA(a) (MCFTIMER_BASE1 + (a))
|
|
|
|
/*
|
|
* These provide the underlying interrupt vector support.
|
|
* Unfortunately it is a little different on each ColdFire.
|
|
*/
|
|
void coldfire_profile_init(void);
|
|
|
|
#if defined(CONFIG_M532x) || defined(CONFIG_M5441x)
|
|
#define __raw_readtrr __raw_readl
|
|
#define __raw_writetrr __raw_writel
|
|
#else
|
|
#define __raw_readtrr __raw_readw
|
|
#define __raw_writetrr __raw_writew
|
|
#endif
|
|
|
|
static u32 mcftmr_cycles_per_jiffy;
|
|
static u32 mcftmr_cnt;
|
|
|
|
static irq_handler_t timer_interrupt;
|
|
|
|
/***************************************************************************/
|
|
|
|
static void init_timer_irq(void)
|
|
{
|
|
#ifdef MCFSIM_ICR_AUTOVEC
|
|
/* Timer1 is always used as system timer */
|
|
writeb(MCFSIM_ICR_AUTOVEC | MCFSIM_ICR_LEVEL6 | MCFSIM_ICR_PRI3,
|
|
MCFSIM_TIMER1ICR);
|
|
mcf_mapirq2imr(MCF_IRQ_TIMER, MCFINTC_TIMER1);
|
|
|
|
#ifdef CONFIG_HIGHPROFILE
|
|
/* Timer2 is to be used as a high speed profile timer */
|
|
writeb(MCFSIM_ICR_AUTOVEC | MCFSIM_ICR_LEVEL7 | MCFSIM_ICR_PRI3,
|
|
MCFSIM_TIMER2ICR);
|
|
mcf_mapirq2imr(MCF_IRQ_PROFILER, MCFINTC_TIMER2);
|
|
#endif
|
|
#endif /* MCFSIM_ICR_AUTOVEC */
|
|
}
|
|
|
|
/***************************************************************************/
|
|
|
|
static irqreturn_t mcftmr_tick(int irq, void *dummy)
|
|
{
|
|
/* Reset the ColdFire timer */
|
|
__raw_writeb(MCFTIMER_TER_CAP | MCFTIMER_TER_REF, TA(MCFTIMER_TER));
|
|
|
|
mcftmr_cnt += mcftmr_cycles_per_jiffy;
|
|
return timer_interrupt(irq, dummy);
|
|
}
|
|
|
|
/***************************************************************************/
|
|
|
|
static struct irqaction mcftmr_timer_irq = {
|
|
.name = "timer",
|
|
.flags = IRQF_DISABLED | IRQF_TIMER,
|
|
.handler = mcftmr_tick,
|
|
};
|
|
|
|
/***************************************************************************/
|
|
|
|
static cycle_t mcftmr_read_clk(struct clocksource *cs)
|
|
{
|
|
unsigned long flags;
|
|
u32 cycles;
|
|
u16 tcn;
|
|
|
|
local_irq_save(flags);
|
|
tcn = __raw_readw(TA(MCFTIMER_TCN));
|
|
cycles = mcftmr_cnt;
|
|
local_irq_restore(flags);
|
|
|
|
return cycles + tcn;
|
|
}
|
|
|
|
/***************************************************************************/
|
|
|
|
static struct clocksource mcftmr_clk = {
|
|
.name = "tmr",
|
|
.rating = 250,
|
|
.read = mcftmr_read_clk,
|
|
.mask = CLOCKSOURCE_MASK(32),
|
|
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
|
|
};
|
|
|
|
/***************************************************************************/
|
|
|
|
void hw_timer_init(irq_handler_t handler)
|
|
{
|
|
__raw_writew(MCFTIMER_TMR_DISABLE, TA(MCFTIMER_TMR));
|
|
mcftmr_cycles_per_jiffy = FREQ / HZ;
|
|
/*
|
|
* The coldfire timer runs from 0 to TRR included, then 0
|
|
* again and so on. It counts thus actually TRR + 1 steps
|
|
* for 1 tick, not TRR. So if you want n cycles,
|
|
* initialize TRR with n - 1.
|
|
*/
|
|
__raw_writetrr(mcftmr_cycles_per_jiffy - 1, TA(MCFTIMER_TRR));
|
|
__raw_writew(MCFTIMER_TMR_ENORI | MCFTIMER_TMR_CLK16 |
|
|
MCFTIMER_TMR_RESTART | MCFTIMER_TMR_ENABLE, TA(MCFTIMER_TMR));
|
|
|
|
clocksource_register_hz(&mcftmr_clk, FREQ);
|
|
|
|
timer_interrupt = handler;
|
|
init_timer_irq();
|
|
setup_irq(MCF_IRQ_TIMER, &mcftmr_timer_irq);
|
|
|
|
#ifdef CONFIG_HIGHPROFILE
|
|
coldfire_profile_init();
|
|
#endif
|
|
}
|
|
|
|
/***************************************************************************/
|
|
#ifdef CONFIG_HIGHPROFILE
|
|
/***************************************************************************/
|
|
|
|
/*
|
|
* By default use timer2 as the profiler clock timer.
|
|
*/
|
|
#define PA(a) (MCFTIMER_BASE2 + (a))
|
|
|
|
/*
|
|
* Choose a reasonably fast profile timer. Make it an odd value to
|
|
* try and get good coverage of kernel operations.
|
|
*/
|
|
#define PROFILEHZ 1013
|
|
|
|
/*
|
|
* Use the other timer to provide high accuracy profiling info.
|
|
*/
|
|
irqreturn_t coldfire_profile_tick(int irq, void *dummy)
|
|
{
|
|
/* Reset ColdFire timer2 */
|
|
__raw_writeb(MCFTIMER_TER_CAP | MCFTIMER_TER_REF, PA(MCFTIMER_TER));
|
|
if (current->pid)
|
|
profile_tick(CPU_PROFILING);
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
/***************************************************************************/
|
|
|
|
static struct irqaction coldfire_profile_irq = {
|
|
.name = "profile timer",
|
|
.flags = IRQF_DISABLED | IRQF_TIMER,
|
|
.handler = coldfire_profile_tick,
|
|
};
|
|
|
|
void coldfire_profile_init(void)
|
|
{
|
|
printk(KERN_INFO "PROFILE: lodging TIMER2 @ %dHz as profile timer\n",
|
|
PROFILEHZ);
|
|
|
|
/* Set up TIMER 2 as high speed profile clock */
|
|
__raw_writew(MCFTIMER_TMR_DISABLE, PA(MCFTIMER_TMR));
|
|
|
|
__raw_writetrr(((MCF_BUSCLK / 16) / PROFILEHZ), PA(MCFTIMER_TRR));
|
|
__raw_writew(MCFTIMER_TMR_ENORI | MCFTIMER_TMR_CLK16 |
|
|
MCFTIMER_TMR_RESTART | MCFTIMER_TMR_ENABLE, PA(MCFTIMER_TMR));
|
|
|
|
setup_irq(MCF_IRQ_PROFILER, &coldfire_profile_irq);
|
|
}
|
|
|
|
/***************************************************************************/
|
|
#endif /* CONFIG_HIGHPROFILE */
|
|
/***************************************************************************/
|