diff options
Diffstat (limited to 'arch/m68knommu/platform/coldfire')
| -rw-r--r-- | arch/m68knommu/platform/coldfire/timers.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/arch/m68knommu/platform/coldfire/timers.c b/arch/m68knommu/platform/coldfire/timers.c new file mode 100644 index 00000000000..489dec85c85 --- /dev/null +++ b/arch/m68knommu/platform/coldfire/timers.c @@ -0,0 +1,155 @@ +/***************************************************************************/ + +/* + * timers.c -- generic ColdFire hardware timer support. + * + * Copyright (C) 1999-2007, 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 <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 TA(a) (MCF_MBAR + MCFTIMER_BASE1 + (a)) + +/* + * Default the timer and vector to use for ColdFire. Some ColdFire + * CPU's and some boards may want different. Their sub-architecture + * startup code (in config.c) can change these if they want. + */ +unsigned int mcf_timervector = 29; +unsigned int mcf_profilevector = 31; +unsigned int mcf_timerlevel = 5; + +/* + * These provide the underlying interrupt vector support. + * Unfortunately it is a little different on each ColdFire. + */ +extern void mcf_settimericr(int timer, int level); +extern int mcf_timerirqpending(int timer); + +#if defined(CONFIG_M532x) +#define __raw_readtrr __raw_readl +#define __raw_writetrr __raw_writel +#else +#define __raw_readtrr __raw_readw +#define __raw_writetrr __raw_writew +#endif + +/***************************************************************************/ + +static irqreturn_t hw_tick(int irq, void *dummy) +{ + /* Reset the ColdFire timer */ + __raw_writeb(MCFTIMER_TER_CAP | MCFTIMER_TER_REF, TA(MCFTIMER_TER)); + + return arch_timer_interrupt(irq, dummy); +} + +/***************************************************************************/ + +static struct irqaction coldfire_timer_irq = { + .name = "timer", + .flags = IRQF_DISABLED | IRQF_TIMER, + .handler = hw_tick, +}; + +/***************************************************************************/ + +static int ticks_per_intr; + +void hw_timer_init(void) +{ + setup_irq(mcf_timervector, &coldfire_timer_irq); + + __raw_writew(MCFTIMER_TMR_DISABLE, TA(MCFTIMER_TMR)); + ticks_per_intr = (MCF_BUSCLK / 16) / HZ; + __raw_writetrr(ticks_per_intr - 1, TA(MCFTIMER_TRR)); + __raw_writew(MCFTIMER_TMR_ENORI | MCFTIMER_TMR_CLK16 | + MCFTIMER_TMR_RESTART | MCFTIMER_TMR_ENABLE, TA(MCFTIMER_TMR)); + + mcf_settimericr(1, mcf_timerlevel); + +#ifdef CONFIG_HIGHPROFILE + coldfire_profile_init(); +#endif +} + +/***************************************************************************/ + +unsigned long hw_timer_offset(void) +{ + unsigned long tcn, offset; + + tcn = __raw_readw(TA(MCFTIMER_TCN)); + offset = ((tcn + 1) * (1000000 / HZ)) / ticks_per_intr; + + /* Check if we just wrapped the counters and maybe missed a tick */ + if ((offset < (1000000 / HZ / 2)) && mcf_timerirqpending(1)) + offset += 1000000 / HZ; + return offset; +} + +/***************************************************************************/ +#ifdef CONFIG_HIGHPROFILE +/***************************************************************************/ + +/* + * By default use timer2 as the profiler clock timer. + */ +#define PA(a) (MCF_MBAR + 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, regs); + return IRQ_HANDLED; +} + +/***************************************************************************/ + +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_CLK / 16) / PROFILEHZ), PA(MCFTIMER_TRR)); + __raw_writew(MCFTIMER_TMR_ENORI | MCFTIMER_TMR_CLK16 | + MCFTIMER_TMR_RESTART | MCFTIMER_TMR_ENABLE, PA(MCFTIMER_TMR)); + + request_irq(mcf_profilevector, coldfire_profile_tick, + (IRQF_DISABLED | IRQ_FLG_FAST), "profile timer", NULL); + mcf_settimericr(2, 7); +} + +/***************************************************************************/ +#endif /* CONFIG_HIGHPROFILE */ +/***************************************************************************/ |