From 5094b92f1c7d0f21c5d4411ba7415bac0684210f Mon Sep 17 00:00:00 2001 From: Russell King Date: Wed, 15 Dec 2010 21:49:06 +0000 Subject: 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 --- arch/arm/mach-sa1100/time.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) (limited to 'arch/arm/mach-sa1100/time.c') 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 #include #include +#include /* just for sched_clock() - funny that */ #include #include #include +#include #include +/* + * 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 = -- cgit v1.2.3