diff options
Diffstat (limited to 'arch/blackfin/kernel/time-ts.c')
| -rw-r--r-- | arch/blackfin/kernel/time-ts.c | 57 |
1 files changed, 32 insertions, 25 deletions
diff --git a/arch/blackfin/kernel/time-ts.c b/arch/blackfin/kernel/time-ts.c index f9715764383e..17c38c5b5b22 100644 --- a/arch/blackfin/kernel/time-ts.c +++ b/arch/blackfin/kernel/time-ts.c @@ -1,13 +1,13 @@ /* - * linux/arch/kernel/time-ts.c - * * Based on arm clockevents implementation and old bfin time tick. * - * Copyright(C) 2008, GeoTechnologies, Vitja Makarov + * Copyright 2008-2009 Analog Devics Inc. + * 2008 GeoTechnologies + * Vitja Makarov * - * This code is licenced under the GPL version 2. For details see - * kernel-base/COPYING. + * Licensed under the GPL-2 */ + #include <linux/module.h> #include <linux/profile.h> #include <linux/interrupt.h> @@ -22,8 +22,6 @@ #include <asm/time.h> #include <asm/gptimers.h> -#if defined(CONFIG_CYCLES_CLOCKSOURCE) - /* Accelerators for sched_clock() * convert from cycles(64bits) => nanoseconds (64bits) * basic equation: @@ -46,20 +44,11 @@ * -johnstul@us.ibm.com "math is hard, lets go shopping!" */ -static unsigned long cyc2ns_scale; #define CYC2NS_SCALE_FACTOR 10 /* 2^10, carefully chosen */ -static inline void set_cyc2ns_scale(unsigned long cpu_khz) -{ - cyc2ns_scale = (1000000 << CYC2NS_SCALE_FACTOR) / cpu_khz; -} - -static inline unsigned long long cycles_2_ns(cycle_t cyc) -{ - return (cyc * cyc2ns_scale) >> CYC2NS_SCALE_FACTOR; -} +#if defined(CONFIG_CYCLES_CLOCKSOURCE) -static cycle_t bfin_read_cycles(struct clocksource *cs) +static notrace cycle_t bfin_read_cycles(struct clocksource *cs) { return __bfin_cycles_off + (get_cycles() << __bfin_cycles_mod); } @@ -69,19 +58,18 @@ static struct clocksource bfin_cs_cycles = { .rating = 400, .read = bfin_read_cycles, .mask = CLOCKSOURCE_MASK(64), - .shift = 22, + .shift = CYC2NS_SCALE_FACTOR, .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; -unsigned long long sched_clock(void) +static inline unsigned long long bfin_cs_cycles_sched_clock(void) { - return cycles_2_ns(bfin_read_cycles(&bfin_cs_cycles)); + return clocksource_cyc2ns(bfin_read_cycles(&bfin_cs_cycles), + bfin_cs_cycles.mult, bfin_cs_cycles.shift); } static int __init bfin_cs_cycles_init(void) { - set_cyc2ns_scale(get_cclk() / 1000); - bfin_cs_cycles.mult = \ clocksource_hz2mult(get_cclk(), bfin_cs_cycles.shift); @@ -108,7 +96,7 @@ void __init setup_gptimer0(void) enable_gptimers(TIMER0bit); } -static cycle_t bfin_read_gptimer0(void) +static cycle_t bfin_read_gptimer0(struct clocksource *cs) { return bfin_read_TIMER0_COUNTER(); } @@ -118,10 +106,16 @@ static struct clocksource bfin_cs_gptimer0 = { .rating = 350, .read = bfin_read_gptimer0, .mask = CLOCKSOURCE_MASK(32), - .shift = 22, + .shift = CYC2NS_SCALE_FACTOR, .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; +static inline unsigned long long bfin_cs_gptimer0_sched_clock(void) +{ + return clocksource_cyc2ns(bfin_read_TIMER0_COUNTER(), + bfin_cs_gptimer0.mult, bfin_cs_gptimer0.shift); +} + static int __init bfin_cs_gptimer0_init(void) { setup_gptimer0(); @@ -138,6 +132,19 @@ static int __init bfin_cs_gptimer0_init(void) # define bfin_cs_gptimer0_init() #endif + +#if defined(CONFIG_GPTMR0_CLOCKSOURCE) || defined(CONFIG_CYCLES_CLOCKSOURCE) +/* prefer to use cycles since it has higher rating */ +notrace unsigned long long sched_clock(void) +{ +#if defined(CONFIG_CYCLES_CLOCKSOURCE) + return bfin_cs_cycles_sched_clock(); +#else + return bfin_cs_gptimer0_sched_clock(); +#endif +} +#endif + #ifdef CONFIG_CORE_TIMER_IRQ_L1 __attribute__((l1_text)) #endif |