/***************************************************************************/ /* * 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_M53xx) || 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_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_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 */ /***************************************************************************/