[PATCH 1/3] ARM: mmp: Also start timer 1 on boot.
From: Lennert Buytenhek <hidden>
Date: 2011-08-01 22:43:10
Subsystem:
arm port, mmp support, the rest · Maintainers:
Russell King, Linus Torvalds
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 <redacted> --- 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 99833b9..b0ce1a8 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 = {
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1.7.6