m68knommu: switch ColdFire TIMER to use GENERIC_TIME
authorGreg Ungerer <gerg@snapgear.com>
Fri, 1 Feb 2008 07:40:26 +0000 (17:40 +1000)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 1 Feb 2008 10:02:03 +0000 (21:02 +1100)
Switch the ColdFire TIMER timer to use GENERIC_TIME.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
arch/m68knommu/platform/coldfire/timers.c

index 489dec85c8594e8fa5d46eedf8478ec01cd249d3..a60213e877ef1b8695a2c836ca5038301106f20a 100644 (file)
@@ -3,7 +3,7 @@
 /*
  *     timers.c -- generic ColdFire hardware timer support.
  *
- *     Copyright (C) 1999-2007, Greg Ungerer (gerg@snapgear.com)
+ *     Copyright (C) 1999-2008, Greg Ungerer <gerg@snapgear.com>
  */
 
 /***************************************************************************/
@@ -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
@@ -90,21 +125,6 @@ void hw_timer_init(void)
 #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
 /***************************************************************************/