Merge tag 'v2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

[mv-sheeva.git] / arch / arm / plat-nomadik / timer.c

diff --git a/arch/arm/plat-nomadik/timer.c b/arch/arm/plat-nomadik/timer.c
index 63cdc6025bd74dfaf46bc93ec49125e9f75bb49d..41723402006b44d932d40f9c216d36f99911f10b 100644 (file)
--- a/arch/arm/plat-nomadik/timer.c
+++ b/arch/arm/plat-nomadik/timer.c
@@ -17,9 +17,9 @@
 #include <linux/clk.h>
 #include <linux/jiffies.h>
 #include <linux/err.h>
-#include <linux/cnt32_to_63.h>
-#include <linux/timer.h>
+#include <linux/sched.h>
 #include <asm/mach/time.h>
+#include <asm/sched_clock.h>
 
 #include <plat/mtu.h>
 
@@ -52,81 +52,24 @@ static struct clocksource nmdk_clksrc = {
  * Override the global weak sched_clock symbol with this
  * local implementation which uses the clocksource to get some
  * better resolution when scheduling the kernel.
- *
- * Because the hardware timer period may be quite short
- * (32.3 secs on the 133 MHz MTU timer selection on ux500)
- * and because cnt32_to_63() needs to be called at least once per
- * half period to work properly, a kernel keepwarm() timer is set up
- * to ensure this requirement is always met.
- *
- * Also the sched_clock timer will wrap around at some point,
- * here we set it to run continously for a year.
  */
-#define SCHED_CLOCK_MIN_WRAP 3600*24*365
-static struct timer_list cnt32_to_63_keepwarm_timer;
-static u32 sched_mult;
-static u32 sched_shift;
+static DEFINE_CLOCK_DATA(cd);
 
 unsigned long long notrace sched_clock(void)
 {
-       u64 cycles;
+       u32 cyc;
 
        if (unlikely(!mtu_base))
                return 0;
 
-       cycles = cnt32_to_63(-readl(mtu_base + MTU_VAL(0)));
-       /*
-        * sched_mult is guaranteed to be even so will
-        * shift out bit 63
-        */
-       return (cycles * sched_mult) >> sched_shift;
+       cyc = -readl(mtu_base + MTU_VAL(0));
+       return cyc_to_sched_clock(&cd, cyc, (u32)~0);
 }
 
-/* Just kick sched_clock every so often */
-static void cnt32_to_63_keepwarm(unsigned long data)
+static void notrace nomadik_update_sched_clock(void)
 {
-       mod_timer(&cnt32_to_63_keepwarm_timer, round_jiffies(jiffies + data));
-       (void) sched_clock();
-}
-
-/*
- * Set up a timer to keep sched_clock():s 32_to_63 algorithm warm
- * once in half a 32bit timer wrap interval.
- */
-static void __init nmdk_sched_clock_init(unsigned long rate)
-{
-       u32 v;
-       unsigned long delta;
-       u64 days;
-
-       /* Find the apropriate mult and shift factors */
-       clocks_calc_mult_shift(&sched_mult, &sched_shift,
-                              rate, NSEC_PER_SEC, SCHED_CLOCK_MIN_WRAP);
-       /* We need to multiply by an even number to get rid of bit 63 */
-       if (sched_mult & 1)
-               sched_mult++;
-
-       /* Let's see what we get, take max counter and scale it */
-       days = (0xFFFFFFFFFFFFFFFFLLU * sched_mult) >> sched_shift;
-       do_div(days, NSEC_PER_SEC);
-       do_div(days, (3600*24));
-
-       pr_info("sched_clock: using %d bits @ %lu Hz wrap in %lu days\n",
-               (64 - sched_shift), rate, (unsigned long) days);
-
-       /*
-        * Program a timer to kick us at half 32bit wraparound
-        * Formula: seconds per wrap = (2^32) / f
-        */
-       v = 0xFFFFFFFFUL / rate;
-       /* We want half of the wrap time to keep cnt32_to_63 warm */
-       v /= 2;
-       pr_debug("sched_clock: prescaled timer rate: %lu Hz, "
-                "initialize keepwarm timer every %d seconds\n", rate, v);
-       /* Convert seconds to jiffies */
-       delta = msecs_to_jiffies(v*1000);
-       setup_timer(&cnt32_to_63_keepwarm_timer, cnt32_to_63_keepwarm, delta);
-       mod_timer(&cnt32_to_63_keepwarm_timer, round_jiffies(jiffies + delta));
+       u32 cyc = -readl(mtu_base + MTU_VAL(0));
+       update_sched_clock(&cd, cyc, (u32)~0);
 }
 
 /* Clockevent device: use one-shot mode */
@@ -222,7 +165,6 @@ void __init nmdk_timer_init(void)
        } else {
                cr |= MTU_CRn_PRESCALE_1;
        }
-       clocksource_calc_mult_shift(&nmdk_clksrc, rate, MTU_MIN_RANGE);
 
        /* Timer 0 is the free running clocksource */
        writel(cr, mtu_base + MTU_CR(0));
@@ -233,11 +175,11 @@ void __init nmdk_timer_init(void)
        /* Now the clock source is ready */
        nmdk_clksrc.read = nmdk_read_timer;
 
-       if (clocksource_register(&nmdk_clksrc))
+       if (clocksource_register_hz(&nmdk_clksrc, rate))
                pr_err("timer: failed to initialize clock source %s\n",
                       nmdk_clksrc.name);
 
-       nmdk_sched_clock_init(rate);
+       init_sched_clock(&cd, nomadik_update_sched_clock, 32, rate);
 
        /* Timer 1 is used for events */