summaryrefslogtreecommitdiff
path: root/arch/arm/mach-ebsa110/core.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2012-03-23 17:30:49 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-03-23 17:30:49 -0700
commit56c10bf82c10588b743e75a13a7949e11b9fc942 (patch)
treea2eda0459abb314107ac64af770bf7fb360aefc6 /arch/arm/mach-ebsa110/core.c
parentbab2d8c6020e1d7521cb6c4939f72b061ce947bc (diff)
parent61b80086a525c8a6081257ae40da5dee2bcaee16 (diff)
Merge branch 'for-armsoc' of git://git.linaro.org/people/rmk/linux-arm
Pull #1 ARM updates from Russell King: "This one covers stuff which Arnd is waiting for me to push, as this is shared between both our trees and probably other trees elsewhere. Essentially, this contains: - AMBA primecell device initializer updates - mostly shrinking the size of the device declarations in platform code to something more reasonable. - Getting rid of the NO_IRQ crap from AMBA primecell stuff. - Nicolas' idle cleanups. This in combination with the restart cleanups from the last merge window results in a great many mach/system.h files being deleted." Yay: ~80 files, ~2000 lines deleted. * 'for-armsoc' of git://git.linaro.org/people/rmk/linux-arm: (60 commits) ARM: remove disable_fiq and arch_ret_to_user macros ARM: make entry-macro.S depend on !MULTI_IRQ_HANDLER ARM: rpc: make default fiq handler run-time installed ARM: make arch_ret_to_user macro optional ARM: amba: samsung: use common amba device initializers ARM: amba: spear: use common amba device initializers ARM: amba: nomadik: use common amba device initializers ARM: amba: u300: use common amba device initializers ARM: amba: lpc32xx: use common amba device initializers ARM: amba: netx: use common amba device initializers ARM: amba: bcmring: use common amba device initializers ARM: amba: ep93xx: use common amba device initializers ARM: amba: omap2: use common amba device initializers ARM: amba: integrator: use common amba device initializers ARM: amba: realview: get rid of private platform amba_device initializer ARM: amba: versatile: get rid of private platform amba_device initializer ARM: amba: vexpress: get rid of private platform amba_device initializer ARM: amba: provide common initializers for static amba devices ARM: amba: make use of -1 IRQs warn ARM: amba: u300: get rid of NO_IRQ initializers ...
Diffstat (limited to 'arch/arm/mach-ebsa110/core.c')
-rw-r--r--arch/arm/mach-ebsa110/core.c25
1 files changed, 25 insertions, 0 deletions
diff --git a/arch/arm/mach-ebsa110/core.c b/arch/arm/mach-ebsa110/core.c
index 294aad07f7a..804c9122b7b 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));
}