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author | Arnd Bergmann <arnd@arndb.de> | 2012-03-21 18:27:34 +0400 |
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committer | Arnd Bergmann <arnd@arndb.de> | 2012-03-21 18:27:34 +0400 |
commit | 2cbe23e3a432e3d09a849adb197c8fcc09e7391d (patch) | |
tree | 711fe5845c4c7e7eaf8c57a597d86c0f9dda5b06 /arch/arm/mach-ebsa110/core.c | |
parent | b2f1df8d2fc14bf7e6d9d967043d4b60c2efd8dc (diff) | |
parent | ed1b4acc43b0c3289faa30cf184f322ab70a5be3 (diff) | |
download | linux-2cbe23e3a432e3d09a849adb197c8fcc09e7391d.tar.xz |
Merge branch 'tegra/cleanups' into next/timer
Conflicts:
arch/arm/mach-tegra/Makefile
arch/arm/mach-vexpress/core.h
The tegra Makefile was changed in four different branches
in the same line. This merge should reduce the amount
of churn.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch/arm/mach-ebsa110/core.c')
-rw-r--r-- | arch/arm/mach-ebsa110/core.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/arch/arm/mach-ebsa110/core.c b/arch/arm/mach-ebsa110/core.c index 294aad07f7a0..804c9122b7b3 100644 --- a/arch/arm/mach-ebsa110/core.c +++ b/arch/arm/mach-ebsa110/core.c @@ -271,8 +271,33 @@ static struct platform_device *ebsa110_devices[] = { &am79c961_device, }; +/* + * EBSA110 idling methodology: + * + * We can not execute the "wait for interrupt" instruction since that + * will stop our MCLK signal (which provides the clock for the glue + * logic, and therefore the timer interrupt). + * + * Instead, we spin, polling the IRQ_STAT register for the occurrence + * of any interrupt with core clock down to the memory clock. + */ +static void ebsa110_idle(void) +{ + const char *irq_stat = (char *)0xff000000; + + /* disable clock switching */ + asm volatile ("mcr p15, 0, ip, c15, c2, 2" : : : "cc"); + + /* wait for an interrupt to occur */ + while (!*irq_stat); + + /* enable clock switching */ + asm volatile ("mcr p15, 0, ip, c15, c1, 2" : : : "cc"); +} + static int __init ebsa110_init(void) { + arm_pm_idle = ebsa110_idle; return platform_add_devices(ebsa110_devices, ARRAY_SIZE(ebsa110_devices)); } |