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authorStephen Boyd <sboyd@codeaurora.org>2011-11-08 10:34:05 -0800
committerDavid Brown <davidb@codeaurora.org>2011-11-10 10:36:33 -0800
commitdd15ab814149df65187943c32ca09e4eeaac0047 (patch)
tree909789e3f7517e50882a42d5be7c1d99d3ad9856 /arch/arm/mach-msm/timer.c
parent4a1840755294b2a14236ee7b9c74ede261156b09 (diff)
msm: timer: Use GPT for clockevents and DGT for clocksource
The clocksource shouldn't stop ticking when the clockevent stops. This is exactly what happens today with MSM timers. The same hardware is used for both the clockevent and the clocksource because the ratings of the two are the same. Fix this by registering a clockevent based on the GPT and a clocksource based on the DGT. This removes any other possible configuration (e.g. a GPT clocksource and a DGT clockevent) but that shouldn't be a big issue since we want higher precision timing than high precision scheduling interrupts. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: David Brown <davidb@codeaurora.org>
Diffstat (limited to 'arch/arm/mach-msm/timer.c')
-rw-r--r--arch/arm/mach-msm/timer.c121
1 files changed, 52 insertions, 69 deletions
diff --git a/arch/arm/mach-msm/timer.c b/arch/arm/mach-msm/timer.c
index ce389ca4950f..405e8a925202 100644
--- a/arch/arm/mach-msm/timer.c
+++ b/arch/arm/mach-msm/timer.c
@@ -1,6 +1,7 @@
-/* linux/arch/arm/mach-msm/timer.c
+/*
*
* Copyright (C) 2007 Google, Inc.
+ * Copyright (c) 2009-2011, Code Aurora Forum. All rights reserved.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
@@ -39,7 +40,7 @@
#define GPT_HZ 32768
-#define MSM_GLOBAL_TIMER MSM_CLOCK_DGT
+#define MSM_GLOBAL_TIMER MSM_CLOCK_GPT
/* TODO: Remove these ifdefs */
#if defined(CONFIG_ARCH_QSD8X50)
@@ -153,25 +154,10 @@ static struct msm_clock msm_clocks[] = {
.set_next_event = msm_timer_set_next_event,
.set_mode = msm_timer_set_mode,
},
- .clocksource = {
- .name = "gp_timer",
- .rating = 200,
- .read = msm_read_timer_count,
- .mask = CLOCKSOURCE_MASK(32),
- .flags = CLOCK_SOURCE_IS_CONTINUOUS,
- },
.irq = INT_GP_TIMER_EXP,
.freq = GPT_HZ,
},
[MSM_CLOCK_DGT] = {
- .clockevent = {
- .name = "dg_timer",
- .features = CLOCK_EVT_FEAT_ONESHOT,
- .shift = 32 + MSM_DGT_SHIFT,
- .rating = 300,
- .set_next_event = msm_timer_set_next_event,
- .set_mode = msm_timer_set_mode,
- },
.clocksource = {
.name = "dg_timer",
.rating = 300,
@@ -179,7 +165,6 @@ static struct msm_clock msm_clocks[] = {
.mask = CLOCKSOURCE_MASK((32 - MSM_DGT_SHIFT)),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
},
- .irq = INT_DEBUG_TIMER_EXP,
.freq = DGT_HZ >> MSM_DGT_SHIFT,
.shift = MSM_DGT_SHIFT,
}
@@ -187,10 +172,13 @@ static struct msm_clock msm_clocks[] = {
static void __init msm_timer_init(void)
{
- int i;
+ struct msm_clock *clock;
+ struct clock_event_device *ce = &msm_clocks[MSM_CLOCK_GPT].clockevent;
+ struct clocksource *cs = &msm_clocks[MSM_CLOCK_DGT].clocksource;
int res;
int global_offset = 0;
+
if (cpu_is_msm7x01()) {
msm_clocks[MSM_CLOCK_GPT].regbase = MSM_CSR_BASE;
msm_clocks[MSM_CLOCK_DGT].regbase = MSM_CSR_BASE + 0x10;
@@ -213,58 +201,55 @@ static void __init msm_timer_init(void)
writel(DGT_CLK_CTL_DIV_4, MSM_TMR_BASE + DGT_CLK_CTL);
#endif
- for (i = 0; i < ARRAY_SIZE(msm_clocks); i++) {
- struct msm_clock *clock = &msm_clocks[i];
- struct clock_event_device *ce = &clock->clockevent;
- struct clocksource *cs = &clock->clocksource;
-
- clock->local_counter = clock->regbase + TIMER_COUNT_VAL;
- clock->global_counter = clock->local_counter + global_offset;
-
- writel(0, clock->regbase + TIMER_ENABLE);
- writel(0, clock->regbase + TIMER_CLEAR);
- writel(~0, clock->regbase + TIMER_MATCH_VAL);
+ clock = &msm_clocks[MSM_CLOCK_GPT];
+ clock->local_counter = clock->regbase + TIMER_COUNT_VAL;
- ce->mult = div_sc(clock->freq, NSEC_PER_SEC, ce->shift);
- /* allow at least 10 seconds to notice that the timer wrapped */
- ce->max_delta_ns =
- clockevent_delta2ns(0xf0000000 >> clock->shift, ce);
- /* 4 gets rounded down to 3 */
- ce->min_delta_ns = clockevent_delta2ns(4, ce);
- ce->cpumask = cpumask_of(0);
-
- res = clocksource_register_hz(cs, clock->freq);
- if (res)
- printk(KERN_ERR "msm_timer_init: clocksource_register "
- "failed for %s\n", cs->name);
-
- ce->irq = clock->irq;
- if (cpu_is_msm8x60() || cpu_is_msm8960()) {
- clock->percpu_evt = alloc_percpu(struct clock_event_device *);
- if (!clock->percpu_evt) {
- pr_err("msm_timer_init: memory allocation "
- "failed for %s\n", ce->name);
- continue;
- }
-
- *__this_cpu_ptr(clock->percpu_evt) = ce;
- res = request_percpu_irq(ce->irq, msm_timer_interrupt,
- ce->name, clock->percpu_evt);
- if (!res)
- enable_percpu_irq(ce->irq, 0);
- } else {
- clock->evt = ce;
- res = request_irq(ce->irq, msm_timer_interrupt,
- IRQF_TIMER | IRQF_NOBALANCING | IRQF_TRIGGER_RISING,
- ce->name, &clock->evt);
+ writel_relaxed(0, clock->regbase + TIMER_ENABLE);
+ writel_relaxed(0, clock->regbase + TIMER_CLEAR);
+ writel_relaxed(~0, clock->regbase + TIMER_MATCH_VAL);
+ ce->mult = div_sc(clock->freq, NSEC_PER_SEC, ce->shift);
+ /*
+ * allow at least 10 seconds to notice that the timer
+ * wrapped
+ */
+ ce->max_delta_ns =
+ clockevent_delta2ns(0xf0000000 >> clock->shift, ce);
+ /* 4 gets rounded down to 3 */
+ ce->min_delta_ns = clockevent_delta2ns(4, ce);
+ ce->cpumask = cpumask_of(0);
+
+ ce->irq = clock->irq;
+ if (cpu_is_msm8x60() || cpu_is_msm8960()) {
+ clock->percpu_evt = alloc_percpu(struct clock_event_device *);
+ if (!clock->percpu_evt) {
+ pr_err("memory allocation failed for %s\n", ce->name);
+ goto err;
}
- if (res)
- pr_err("msm_timer_init: request_irq failed for %s\n",
- ce->name);
-
- clockevents_register_device(ce);
+ *__this_cpu_ptr(clock->percpu_evt) = ce;
+ res = request_percpu_irq(ce->irq, msm_timer_interrupt,
+ ce->name, clock->percpu_evt);
+ if (!res)
+ enable_percpu_irq(ce->irq, 0);
+ } else {
+ clock->evt = ce;
+ res = request_irq(ce->irq, msm_timer_interrupt,
+ IRQF_TIMER | IRQF_NOBALANCING |
+ IRQF_TRIGGER_RISING, ce->name, &clock->evt);
}
+
+ if (res)
+ pr_err("request_irq failed for %s\n", ce->name);
+
+ clockevents_register_device(ce);
+err:
+ clock = &msm_clocks[MSM_CLOCK_DGT];
+ clock->local_counter = clock->regbase + TIMER_COUNT_VAL;
+ clock->global_counter = clock->local_counter + global_offset;
+ writel_relaxed(TIMER_ENABLE_EN, clock->regbase + TIMER_ENABLE);
+ res = clocksource_register_hz(cs, clock->freq);
+ if (res)
+ pr_err("clocksource_register failed for %s\n", cs->name);
}
#ifdef CONFIG_LOCAL_TIMERS
@@ -277,8 +262,6 @@ int __cpuinit local_timer_setup(struct clock_event_device *evt)
if (!smp_processor_id())
return 0;
- writel(DGT_CLK_CTL_DIV_4, MSM_TMR_BASE + DGT_CLK_CTL);
-
if (!local_timer_inited) {
writel(0, clock->regbase + TIMER_ENABLE);
writel(0, clock->regbase + TIMER_CLEAR);