diff options
Diffstat (limited to 'arch/arm/mach-omap1/time.c')
-rw-r--r-- | arch/arm/mach-omap1/time.c | 40 |
1 files changed, 19 insertions, 21 deletions
diff --git a/arch/arm/mach-omap1/time.c b/arch/arm/mach-omap1/time.c index d540539c9bbb..191a9b1ee9b7 100644 --- a/arch/arm/mach-omap1/time.c +++ b/arch/arm/mach-omap1/time.c @@ -247,13 +247,6 @@ unsigned long long sched_clock(void) #define OMAP_32K_TIMER_TCR 0x04 #define OMAP_32K_TICKS_PER_HZ (32768 / HZ) -#if (32768 % HZ) != 0 -/* We cannot ignore modulo. - * Potential error can be as high as several percent. - */ -#define OMAP_32K_TICK_MODULO (32768 % HZ) -static unsigned modulo_count = 0; /* Counts 1/HZ units */ -#endif /* * TRM says 1 / HZ = ( TVR + 1) / 32768, so TRV = (32768 / HZ) - 1 @@ -296,13 +289,22 @@ static inline void omap_32k_timer_stop(void) } /* - * Rounds down to nearest usec + * Rounds down to nearest usec. Note that this will overflow for larger values. */ static inline unsigned long omap_32k_ticks_to_usecs(unsigned long ticks_32k) { return (ticks_32k * 5*5*5*5*5*5) >> 9; } +/* + * Rounds down to nearest nsec. + */ +static inline unsigned long long +omap_32k_ticks_to_nsecs(unsigned long ticks_32k) +{ + return (unsigned long long) ticks_32k * 1000 * 5*5*5*5*5*5 >> 9; +} + static unsigned long omap_32k_last_tick = 0; /* @@ -315,6 +317,15 @@ static unsigned long omap_32k_timer_gettimeoffset(void) } /* + * Returns current time from boot in nsecs. It's OK for this to wrap + * around for now, as it's just a relative time stamp. + */ +unsigned long long sched_clock(void) +{ + return omap_32k_ticks_to_nsecs(omap_32k_sync_timer_read()); +} + +/* * Timer interrupt for 32KHz timer. When dynamic tick is enabled, this * function is also called from other interrupts to remove latency * issues with dynamic tick. In the dynamic tick case, we need to lock @@ -330,19 +341,6 @@ static irqreturn_t omap_32k_timer_interrupt(int irq, void *dev_id, now = omap_32k_sync_timer_read(); while (now - omap_32k_last_tick >= OMAP_32K_TICKS_PER_HZ) { -#ifdef OMAP_32K_TICK_MODULO - /* Modulo addition may put omap_32k_last_tick ahead of now - * and cause unwanted repetition of the while loop. - */ - if (unlikely(now - omap_32k_last_tick == ~0)) - break; - - modulo_count += OMAP_32K_TICK_MODULO; - if (modulo_count > HZ) { - ++omap_32k_last_tick; - modulo_count -= HZ; - } -#endif omap_32k_last_tick += OMAP_32K_TICKS_PER_HZ; timer_tick(regs); } |