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authorAnders Larsen <al@alarsen.net>2010-04-13 12:05:32 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2010-05-02 23:13:13 +0100
commitaec9562f3db8ece218125042e0b2b7ac5b7091e7 (patch)
tree047bd61d5794b40dd2283f1925af0bdb00f3f0bc
parente2941054ed596dd67a6094b7aca165af1b1f9926 (diff)
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ARM: 6053/1: AT91: Save power by disabling the processor clock when CPU is idle
Disable the processor clock when the CPU is idle. This saves much more power than merely entering 'Wait for Interrupt' mode. Since JTAG-debugging doesn't work when the processor clock is switched off, make it conditional on CONFIG_DEBUG_KERNEL. Signed-off-by: Anders Larsen <al@alarsen.net> Acked-by: Andrew Victor <avictor.za@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
-rw-r--r--arch/arm/mach-at91/include/mach/system.h7
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/arm/mach-at91/include/mach/system.h b/arch/arm/mach-at91/include/mach/system.h
index 5268af3..c80e090 100644
--- a/arch/arm/mach-at91/include/mach/system.h
+++ b/arch/arm/mach-at91/include/mach/system.h
@@ -24,21 +24,24 @@
#include <mach/hardware.h>
#include <mach/at91_st.h>
#include <mach/at91_dbgu.h>
+#include <mach/at91_pmc.h>
static inline void arch_idle(void)
{
+#ifndef CONFIG_DEBUG_KERNEL
/*
* Disable the processor clock. The processor will be automatically
* re-enabled by an interrupt or by a reset.
*/
-// at91_sys_write(AT91_PMC_SCDR, AT91_PMC_PCK);
-
+ at91_sys_write(AT91_PMC_SCDR, AT91_PMC_PCK);
+#else
/*
* Set the processor (CP15) into 'Wait for Interrupt' mode.
* Unlike disabling the processor clock via the PMC (above)
* this allows the processor to be woken via JTAG.
*/
cpu_do_idle();
+#endif
}
void (*at91_arch_reset)(void);
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