From 4342f4ace2335d4fa9fe52b4cceca979413470b2 Mon Sep 17 00:00:00 2001 From: Greg Ungerer Date: Fri, 8 Jun 2007 13:46:39 -0700 Subject: m68knommu: fix ColdFire timer off by 1 The coldfire timer runs from 0 to TRR included, then 0 again and so on. It counts thus actually TRR + 1 steps for 1 tick, not TRR. Fix that. Signed-off-by: Philippe De Muyter Signed-off-by: Greg Ungerer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/m68knommu/platform/5307/timers.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'arch/m68knommu') diff --git a/arch/m68knommu/platform/5307/timers.c b/arch/m68knommu/platform/5307/timers.c index 92e58070b016..fb66eadd5896 100644 --- a/arch/m68knommu/platform/5307/timers.c +++ b/arch/m68knommu/platform/5307/timers.c @@ -62,10 +62,13 @@ void coldfire_tick(void) /***************************************************************************/ +static int ticks_per_intr; + void coldfire_timer_init(irq_handler_t handler) { __raw_writew(MCFTIMER_TMR_DISABLE, TA(MCFTIMER_TMR)); - __raw_writetrr(((MCF_BUSCLK / 16) / HZ), TA(MCFTIMER_TRR)); + ticks_per_intr = (MCF_BUSCLK / 16) / HZ; + __raw_writetrr(ticks_per_intr - 1, TA(MCFTIMER_TRR)); __raw_writew(MCFTIMER_TMR_ENORI | MCFTIMER_TMR_CLK16 | MCFTIMER_TMR_RESTART | MCFTIMER_TMR_ENABLE, TA(MCFTIMER_TMR)); @@ -81,11 +84,10 @@ void coldfire_timer_init(irq_handler_t handler) unsigned long coldfire_timer_offset(void) { - unsigned long trr, tcn, offset; + unsigned long tcn, offset; tcn = __raw_readw(TA(MCFTIMER_TCN)); - trr = __raw_readtrr(TA(MCFTIMER_TRR)); - offset = (tcn * (1000000 / HZ)) / trr; + offset = ((tcn + 1) * (1000000 / HZ)) / ticks_per_intr; /* Check if we just wrapped the counters and maybe missed a tick */ if ((offset < (1000000 / HZ / 2)) && mcf_timerirqpending(1)) -- cgit v1.2.3-59-g8ed1b