diff options
| author | Lennert Buytenhek <buytenh@wantstofly.org> | 2011-08-09 22:36:59 +0400 |
|---|---|---|
| committer | Eric Miao <eric.y.miao@gmail.com> | 2011-08-11 06:10:44 +0400 |
| commit | 7ce5ae39c46f159aee3b3427844f1491e1ccac74 (patch) | |
| tree | da07dbd620cb9cccb72a29559c09c17717c58137 | |
| parent | 4c22ea8f449ce837dd84965badca8e10f1f4094f (diff) | |
| download | linux-7ce5ae39c46f159aee3b3427844f1491e1ccac74.tar.xz | |
ARM: mmp: Also start timer 1 on boot.
Currently, arch-mmp/time.c uses timer 0 both as a clocksource timer
and as a clockevent timer, the latter by setting up a comparator
interrupt to match on 'current_time + delta'. This is problematic
if delta is small enough, as that can lead to 'current_time + delta'
already being in the past when comparator setup has finished, leading
to the requested event not triggering.
As there is also a silicon issue that requires stopping a timer's
counter while writing to one of its match registers, we'll switch to
using two separate timers -- timer 0 as clockevent timer, which we'll
start and stop on every invocation of ->set_next_event(), and timer 1
as clocksource timer, which will be free-running.
This first patch enables timer 1 on boot, so that we can use it as
clocksource timer.
Signed-off-by: Lennert Buytenhek <buytenh@laptop.org>
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
| -rw-r--r-- | arch/arm/mach-mmp/time.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/arch/arm/mach-mmp/time.c b/arch/arm/mach-mmp/time.c index 99833b9485cf..09e88c25fe8e 100644 --- a/arch/arm/mach-mmp/time.c +++ b/arch/arm/mach-mmp/time.c @@ -145,23 +145,26 @@ static struct clocksource cksrc = { static void __init timer_config(void) { uint32_t ccr = __raw_readl(TIMERS_VIRT_BASE + TMR_CCR); - uint32_t cer = __raw_readl(TIMERS_VIRT_BASE + TMR_CER); - uint32_t cmr = __raw_readl(TIMERS_VIRT_BASE + TMR_CMR); - __raw_writel(cer & ~0x1, TIMERS_VIRT_BASE + TMR_CER); /* disable */ + __raw_writel(0x0, TIMERS_VIRT_BASE + TMR_CER); /* disable */ - ccr &= (cpu_is_mmp2()) ? TMR_CCR_CS_0(0) : TMR_CCR_CS_0(3); + ccr &= (cpu_is_mmp2()) ? (TMR_CCR_CS_0(0) | TMR_CCR_CS_1(0)) : + (TMR_CCR_CS_0(3) | TMR_CCR_CS_1(3)); __raw_writel(ccr, TIMERS_VIRT_BASE + TMR_CCR); /* free-running mode */ - __raw_writel(cmr | 0x01, TIMERS_VIRT_BASE + TMR_CMR); + __raw_writel(0x3, TIMERS_VIRT_BASE + TMR_CMR); __raw_writel(0x0, TIMERS_VIRT_BASE + TMR_PLCR(0)); /* free-running */ __raw_writel(0x7, TIMERS_VIRT_BASE + TMR_ICR(0)); /* clear status */ __raw_writel(0x0, TIMERS_VIRT_BASE + TMR_IER(0)); + __raw_writel(0x0, TIMERS_VIRT_BASE + TMR_PLCR(1)); /* free-running */ + __raw_writel(0x7, TIMERS_VIRT_BASE + TMR_ICR(1)); /* clear status */ + __raw_writel(0x0, TIMERS_VIRT_BASE + TMR_IER(1)); + /* enable timer counter */ - __raw_writel(cer | 0x01, TIMERS_VIRT_BASE + TMR_CER); + __raw_writel(0x3, TIMERS_VIRT_BASE + TMR_CER); } static struct irqaction timer_irq = { |