summaryrefslogtreecommitdiff
path: root/arch/m68knommu/platform/5307/timers.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/m68knommu/platform/5307/timers.c')
-rw-r--r--arch/m68knommu/platform/5307/timers.c138
1 files changed, 138 insertions, 0 deletions
diff --git a/arch/m68knommu/platform/5307/timers.c b/arch/m68knommu/platform/5307/timers.c
new file mode 100644
index 000000000000..ef49596aa09c
--- /dev/null
+++ b/arch/m68knommu/platform/5307/timers.c
@@ -0,0 +1,138 @@
+/***************************************************************************/
+
+/*
+ * timers.c -- generic ColdFire hardware timer support.
+ *
+ * Copyright (C) 1999-2003, Greg Ungerer (gerg@snapgear.com)
+ */
+
+/***************************************************************************/
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/param.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <asm/irq.h>
+#include <asm/traps.h>
+#include <asm/machdep.h>
+#include <asm/coldfire.h>
+#include <asm/mcftimer.h>
+#include <asm/mcfsim.h>
+
+/***************************************************************************/
+
+/*
+ * 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;
+
+static volatile struct mcftimer *mcf_timerp;
+
+/*
+ * 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);
+
+/***************************************************************************/
+
+void coldfire_tick(void)
+{
+ /* Reset the ColdFire timer */
+ mcf_timerp->ter = MCFTIMER_TER_CAP | MCFTIMER_TER_REF;
+}
+
+/***************************************************************************/
+
+void coldfire_timer_init(irqreturn_t (*handler)(int, void *, struct pt_regs *))
+{
+ /* Set up an internal TIMER as poll clock */
+ mcf_timerp = (volatile struct mcftimer *) (MCF_MBAR + MCFTIMER_BASE1);
+ mcf_timerp->tmr = MCFTIMER_TMR_DISABLE;
+
+ mcf_timerp->trr = (unsigned short) ((MCF_BUSCLK / 16) / HZ);
+ mcf_timerp->tmr = MCFTIMER_TMR_ENORI | MCFTIMER_TMR_CLK16 |
+ MCFTIMER_TMR_RESTART | MCFTIMER_TMR_ENABLE;
+
+ request_irq(mcf_timervector, handler, SA_INTERRUPT, "timer", NULL);
+ mcf_settimericr(1, mcf_timerlevel);
+
+#ifdef CONFIG_HIGHPROFILE
+ coldfire_profile_init();
+#endif
+}
+
+/***************************************************************************/
+
+unsigned long coldfire_timer_offset(void)
+{
+ unsigned long trr, tcn, offset;
+
+ /*
+ * The change to pointer and de-reference is to force the compiler
+ * to read the registers with a single 16bit access. Otherwise it
+ * does some crazy 8bit read combining.
+ */
+ tcn = *(&mcf_timerp->tcn);
+ trr = *(&mcf_timerp->trr);
+ offset = (tcn * (1000000 / HZ)) / trr;
+
+ /* 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
+/***************************************************************************/
+
+/*
+ * Choose a reasonably fast profile timer. Make it an odd value to
+ * try and get good coverage of kernal operations.
+ */
+#define PROFILEHZ 1013
+
+static volatile struct mcftimer *mcf_proftp;
+
+/*
+ * Use the other timer to provide high accuracy profiling info.
+ */
+
+void coldfire_profile_tick(int irq, void *dummy, struct pt_regs *regs)
+{
+ /* Reset ColdFire timer2 */
+ mcf_proftp->ter = MCFTIMER_TER_CAP | MCFTIMER_TER_REF;
+ if (current->pid)
+ profile_tick(CPU_PROFILING, regs);
+}
+
+/***************************************************************************/
+
+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 */
+ mcf_proftp = (volatile struct mcftimer *) (MCF_MBAR + MCFTIMER_BASE2);
+ mcf_proftp->tmr = MCFTIMER_TMR_DISABLE;
+
+ mcf_proftp->trr = (unsigned short) ((MCF_CLK / 16) / PROFILEHZ);
+ mcf_proftp->tmr = MCFTIMER_TMR_ENORI | MCFTIMER_TMR_CLK16 |
+ MCFTIMER_TMR_RESTART | MCFTIMER_TMR_ENABLE;
+
+ request_irq(mcf_profilevector, coldfire_profile_tick,
+ (SA_INTERRUPT | IRQ_FLG_FAST), "profile timer", NULL);
+ mcf_settimericr(2, 7);
+}
+
+/***************************************************************************/
+#endif /* CONFIG_HIGHPROFILE */
+/***************************************************************************/