[M68KNOMMU 03/07]: switch ColdFire TIMER to use GENERIC_TIME

From: Greg Ungerer
Date: Fri Feb 01 2008 - 02:51:41 EST


Switch the ColdFire TIMER timer to use GENERIC_TIME.

Signed-off-by: Greg Ungerer <gerg@xxxxxxxxxxx>
---


diff -Naurp linux-2.6.24.1/arch/m68knommu/platform/coldfire/timers.c linux-2.6.24.2/arch/m68knommu/platform/coldfire/timers.c
--- linux-2.6.24.1/arch/m68knommu/platform/coldfire/timers.c 2008-01-25 08:58:37.000000000 +1000
+++ linux-2.6.24.2/arch/m68knommu/platform/coldfire/timers.c 2008-02-01 16:15:50.000000000 +1000
@@ -3,7 +3,7 @@
/*
* timers.c -- generic ColdFire hardware timer support.
*
- * Copyright (C) 1999-2007, Greg Ungerer (gerg@xxxxxxxxxxxx)
+ * Copyright (C) 1999-2008, Greg Ungerer <gerg@xxxxxxxxxxxx>
*/

/***************************************************************************/
@@ -13,6 +13,8 @@
#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>
@@ -25,6 +27,7 @@
/*
* By default use timer1 as the system clock timer.
*/
+#define FREQ (MCF_BUSCLK / 16)
#define TA(a) (MCF_MBAR + MCFTIMER_BASE1 + (a))

/*
@@ -41,7 +44,7 @@ unsigned int mcf_timerlevel = 5;
* 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_profile_init(void);

#if defined(CONFIG_M532x)
#define __raw_readtrr __raw_readl
@@ -51,38 +54,70 @@ extern int mcf_timerirqpending(int timer
#define __raw_writetrr __raw_writew
#endif

+static u32 mcftmr_cycles_per_jiffy;
+static u32 mcftmr_cnt;
+
/***************************************************************************/

-static irqreturn_t hw_tick(int irq, void *dummy)
+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 arch_timer_interrupt(irq, dummy);
}

/***************************************************************************/

-static struct irqaction coldfire_timer_irq = {
+static struct irqaction mcftmr_timer_irq = {
.name = "timer",
.flags = IRQF_DISABLED | IRQF_TIMER,
- .handler = hw_tick,
+ .handler = mcftmr_tick,
};

/***************************************************************************/

-static int ticks_per_intr;
+static cycle_t mcftmr_read_clk(void)
+{
+ 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,
+ .shift = 20,
+ .mask = CLOCKSOURCE_MASK(32),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+/***************************************************************************/

void hw_timer_init(void)
{
- setup_irq(mcf_timervector, &coldfire_timer_irq);
+ setup_irq(mcf_timervector, &mcftmr_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));
+ mcftmr_cycles_per_jiffy = FREQ / HZ;
+ __raw_writetrr(mcftmr_cycles_per_jiffy, TA(MCFTIMER_TRR));
__raw_writew(MCFTIMER_TMR_ENORI | MCFTIMER_TMR_CLK16 |
MCFTIMER_TMR_RESTART | MCFTIMER_TMR_ENABLE, TA(MCFTIMER_TMR));

+ mcftmr_clk.mult = clocksource_hz2mult(FREQ, mcftmr_clk.shift);
+ clocksource_register(&mcftmr_clk);
+
mcf_settimericr(1, mcf_timerlevel);

#ifdef CONFIG_HIGHPROFILE
@@ -91,21 +126,6 @@ void hw_timer_init(void)
}

/***************************************************************************/
-
-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
/***************************************************************************/

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