aboutsummaryrefslogtreecommitdiff
path: root/arch/m68knommu/platform/coldfire
diff options
context:
space:
mode:
Diffstat (limited to 'arch/m68knommu/platform/coldfire')
-rw-r--r--arch/m68knommu/platform/coldfire/timers.c155
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 */
+/***************************************************************************/