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-rw-r--r--arch/m68k/coldfire/timers.c195
1 files changed, 195 insertions, 0 deletions
diff --git a/arch/m68k/coldfire/timers.c b/arch/m68k/coldfire/timers.c
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+++ b/arch/m68k/coldfire/timers.c
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+/***************************************************************************/
+
+/*
+ * 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 */
+/***************************************************************************/