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linux/arch/m68k/platform/coldfire/timers.c
Steven King bea8bcb12d m68knommu: Add support for the Coldfire m5441x.
Add support for the Coldfire 5441x (54410/54415/54416/54417/54418).  Currently
we only support noMMU mode.  It requires the PIT patch posted previously as it
uses the PIT instead of the dma timer as a clock source so we can get all that
GENERIC_CLOCKEVENTS goodness.  It also adds some simple clk definitions and
very simple minded power management.  The gpio code is tweeked and some
additional devices are added to devices.c.  The Makefile uses -mv4e as
apparently, the only difference a v4m (m5441x) and a v4e is the later has a
FPU, which I don't think should matter to us in the kernel.

Signed-off-by: Steven King <sfking@fdwdc.com>
Signed-off-by: Greg Ungerer <gerg@uclinux.org>
2012-07-16 09:59:21 +10:00

196 lines
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,
MCF_MBAR + 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,
MCF_MBAR + 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 */
/***************************************************************************/