[PATCHv2 1/3] plat-nomadik: MTU sched_clock as a config option
From: Mattias Wallin
Date: Thu Jun 02 2011 - 05:35:51 EST
To make room for another sched_clk implementation a config
option is added around the sched_clk part of the MTU timer.
This makes it possible to configure away the sched_clk part.
An alternate sched_clk and clocksource is needed for the db8500
chip because the MTU is placed in a none always on power domain and will loose
power in some cpuidle sleep states.
Signed-off-by: Mattias Wallin <mattias.wallin@xxxxxxxxxxxxxx>
Acked-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
arch/arm/plat-nomadik/Kconfig | 8 +++++++-
arch/arm/plat-nomadik/timer.c | 4 ++++
2 files changed, 11 insertions(+), 1 deletions(-)
diff --git a/arch/arm/plat-nomadik/Kconfig b/arch/arm/plat-nomadik/Kconfig
index ce65901..bca4914 100644
--- a/arch/arm/plat-nomadik/Kconfig
+++ b/arch/arm/plat-nomadik/Kconfig
@@ -15,10 +15,16 @@ if PLAT_NOMADIK
config HAS_MTU
bool
- select HAVE_SCHED_CLOCK
help
Support for Multi Timer Unit. MTU provides access
to multiple interrupt generating programmable
32-bit free running decrementing counters.
+config NOMADIK_MTU_SCHED_CLOCK
+ bool
+ depends on HAS_MTU
+ select HAVE_SCHED_CLOCK
+ help
+ Use the Multi Timer Unit as the sched_clock.
+
endif
diff --git a/arch/arm/plat-nomadik/timer.c b/arch/arm/plat-nomadik/timer.c
index ef74e15..b55c4ec 100644
--- a/arch/arm/plat-nomadik/timer.c
+++ b/arch/arm/plat-nomadik/timer.c
@@ -25,6 +25,7 @@
void __iomem *mtu_base; /* Assigned by machine code */
+#ifdef CONFIG_NOMADIK_MTU_SCHED_CLOCK
/*
* Override the global weak sched_clock symbol with this
* local implementation which uses the clocksource to get some
@@ -48,6 +49,7 @@ static void notrace nomadik_update_sched_clock(void)
u32 cyc = -readl(mtu_base + MTU_VAL(0));
update_sched_clock(&cd, cyc, (u32)~0);
}
+#endif
/* Clockevent device: use one-shot mode */
static void nmdk_clkevt_mode(enum clock_event_mode mode,
@@ -154,7 +156,9 @@ void __init nmdk_timer_init(void)
pr_err("timer: failed to initialize clock source %s\n",
"mtu_0");
+#ifdef CONFIG_NOMADIK_MTU_SCHED_CLOCK
init_sched_clock(&cd, nomadik_update_sched_clock, 32, rate);
+#endif
/* Timer 1 is used for events */
--
1.7.4.3
--
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