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| author |   Russell King <rmk+kernel@arm.linux.org.uk> | 2010-12-15 21:49:06 +0000 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2010-12-22 22:44:46 +0000 |
| commit | 5094b92f1c7d0f21c5d4411ba7415bac0684210f (patch) | |
| tree | dd7ea2777e5c0470fe7c46c9b8ec3ed16885ddcb /arch/arm/mach-sa1100 | |
| parent | ARM: pxa: convert sched_clock() to use new infrastructure (diff) | |
| download | linux-dev-5094b92f1c7d0f21c5d4411ba7415bac0684210f.tar.xz linux-dev-5094b92f1c7d0f21c5d4411ba7415bac0684210f.zip | |
ARM: sa1100: convert sched_clock() to use new infrastructure
Convert sa1100 to use the new sched_clock() infrastructure for extending
32bit counters to full 64-bit nanoseconds.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mach-sa1100')
| -rw-r--r-- | arch/arm/mach-sa1100/generic.c | 23 | ||||
| -rw-r--r-- | arch/arm/mach-sa1100/time.c | 30 |
2 files changed, 30 insertions, 23 deletions
diff --git a/arch/arm/mach-sa1100/generic.c b/arch/arm/mach-sa1100/generic.c index 33b4969e9d51..fbc224d88e6f 100644 --- a/arch/arm/mach-sa1100/generic.c +++ b/arch/arm/mach-sa1100/generic.c @@ -16,9 +16,7 @@ #include <linux/pm.h> #include <linux/cpufreq.h> #include <linux/ioport.h> -#include <linux/sched.h> /* just for sched_clock() - funny that */ #include <linux/platform_device.h> -#include <linux/cnt32_to_63.h> #include <asm/div64.h> #include <mach/hardware.h> @@ -110,27 +108,6 @@ unsigned int sa11x0_getspeed(unsigned int cpu) } /* - * This is the SA11x0 sched_clock implementation. This has - * a resolution of 271ns, and a maximum value of 32025597s (370 days). - * - * The return value is guaranteed to be monotonic in that range as - * long as there is always less than 582 seconds between successive - * calls to this function. - * - * ( * 1E9 / 3686400 => * 78125 / 288) - */ -unsigned long long notrace sched_clock(void) -{ - unsigned long long v = cnt32_to_63(OSCR); - - /* the <<1 gets rid of the cnt_32_to_63 top bit saving on a bic insn */ - v *= 78125<<1; - do_div(v, 288<<1); - - return v; -} - -/* * Default power-off for SA1100 */ static void sa1100_power_off(void) diff --git a/arch/arm/mach-sa1100/time.c b/arch/arm/mach-sa1100/time.c index 96154f578cd5..ae4f3d80416f 100644 --- a/arch/arm/mach-sa1100/time.c +++ b/arch/arm/mach-sa1100/time.c @@ -12,12 +12,39 @@ #include <linux/errno.h> #include <linux/interrupt.h> #include <linux/irq.h> +#include <linux/sched.h> /* just for sched_clock() - funny that */ #include <linux/timex.h> #include <linux/clockchips.h> #include <asm/mach/time.h> +#include <asm/sched_clock.h> #include <mach/hardware.h> +/* + * This is the SA11x0 sched_clock implementation. + */ +static DEFINE_CLOCK_DATA(cd); + +/* + * Constants generated by clocks_calc_mult_shift(m, s, 3.6864MHz, + * NSEC_PER_SEC, 60). + * This gives a resolution of about 271ns and a wrap period of about 19min. + */ +#define SC_MULT 2275555556u +#define SC_SHIFT 23 + +unsigned long long notrace sched_clock(void) +{ + u32 cyc = OSCR; + return cyc_to_fixed_sched_clock(&cd, cyc, (u32)~0, SC_MULT, SC_SHIFT); +} + +static void notrace sa1100_update_sched_clock(void) +{ + u32 cyc = OSCR; + update_sched_clock(&cd, cyc, (u32)~0); +} + #define MIN_OSCR_DELTA 2 static irqreturn_t sa1100_ost0_interrupt(int irq, void *dev_id) @@ -96,6 +123,9 @@ static void __init sa1100_timer_init(void) OIER = 0; /* disable any timer interrupts */ OSSR = 0xf; /* clear status on all timers */ + init_fixed_sched_clock(&cd, sa1100_update_sched_clock, 32, + 3686400, SC_MULT, SC_SHIFT); + ckevt_sa1100_osmr0.mult = div_sc(3686400, NSEC_PER_SEC, ckevt_sa1100_osmr0.shift); ckevt_sa1100_osmr0.max_delta_ns = |