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linux-next/arch/arm/mach-ux500/cpuidle.c
Linus Torvalds 99c6bcf46d ARM: arm-soc multiplatform updates for 3.10
More multiplatform enablement for ARM platforms. The ones converted in
 this branch are:
 - bcm2835
 - cns3xxx
 - sirf
 - nomadik
 - msx
 - spear
 - tegra
 - ux500
 
 We're getting close to having most of them converted!
 
 One of the larger platforms remaining is Samsung Exynos, and there are
 a bunch of supporting patches in this merge window for it. There was a
 patch in this branch to a early version of multiplatform conversion,
 but it ended up being reverted due to need of more bake time. The
 revert commit is part of the branch since it would have required
 rebasing multiple dependent branches and they were stable by then.
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Merge tag 'multiplatform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

Pull ARM SoC multiplatform updates from Olof Johansson:
 "More multiplatform enablement for ARM platforms.  The ones converted
  in this branch are:

   - bcm2835
   - cns3xxx
   - sirf
   - nomadik
   - msx
   - spear
   - tegra
   - ux500

  We're getting close to having most of them converted!

  One of the larger platforms remaining is Samsung Exynos, and there are
  a bunch of supporting patches in this merge window for it.  There was
  a patch in this branch to a early version of multiplatform conversion,
  but it ended up being reverted due to need of more bake time.  The
  revert commit is part of the branch since it would have required
  rebasing multiple dependent branches and they were stable by then"

* tag 'multiplatform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (70 commits)
  mmc: sdhci-s3c: Fix operation on non-single image Samsung platforms
  clocksource: nomadik-mtu: fix up clocksource/timer
  Revert "ARM: exynos: enable multiplatform support"
  ARM: SPEAr13xx: Fix typo "ARCH_HAVE_CPUFREQ"
  ARM: exynos: enable multiplatform support
  rtc: s3c: make header file local
  mtd: onenand/samsung: make regs-onenand.h file local
  thermal/exynos: remove unnecessary header inclusions
  mmc: sdhci-s3c: remove platform dependencies
  ARM: samsung: move mfc device definition to s5p-dev-mfc.c
  ARM: exynos: move debug-macro.S to include/debug/
  ARM: exynos: prepare for sparse IRQ
  ARM: exynos: introduce EXYNOS_ATAGS symbol
  ARM: tegra: build assembly files with -march=armv7-a
  ARM: Push selects for TWD/SCU into machine entries
  ARM: ux500: build hotplug.o for ARMv7-a
  ARM: ux500: move to multiplatform
  ARM: ux500: make remaining headers local
  ARM: ux500: make irqs.h local to platform
  ARM: ux500: get rid of <mach/[hardware|db8500-regs].h>
  ...
2013-05-02 09:38:16 -07:00

125 lines
3.1 KiB
C

/*
* Copyright (c) 2012 Linaro : Daniel Lezcano <daniel.lezcano@linaro.org> (IBM)
*
* Based on the work of Rickard Andersson <rickard.andersson@stericsson.com>
* and Jonas Aaberg <jonas.aberg@stericsson.com>.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/cpuidle.h>
#include <linux/spinlock.h>
#include <linux/atomic.h>
#include <linux/smp.h>
#include <linux/mfd/dbx500-prcmu.h>
#include <linux/platform_data/arm-ux500-pm.h>
#include <asm/cpuidle.h>
#include <asm/proc-fns.h>
#include "db8500-regs.h"
static atomic_t master = ATOMIC_INIT(0);
static DEFINE_SPINLOCK(master_lock);
static inline int ux500_enter_idle(struct cpuidle_device *dev,
struct cpuidle_driver *drv, int index)
{
int this_cpu = smp_processor_id();
bool recouple = false;
if (atomic_inc_return(&master) == num_online_cpus()) {
/* With this lock, we prevent the other cpu to exit and enter
* this function again and become the master */
if (!spin_trylock(&master_lock))
goto wfi;
/* decouple the gic from the A9 cores */
if (prcmu_gic_decouple()) {
spin_unlock(&master_lock);
goto out;
}
/* If an error occur, we will have to recouple the gic
* manually */
recouple = true;
/* At this state, as the gic is decoupled, if the other
* cpu is in WFI, we have the guarantee it won't be wake
* up, so we can safely go to retention */
if (!prcmu_is_cpu_in_wfi(this_cpu ? 0 : 1))
goto out;
/* The prcmu will be in charge of watching the interrupts
* and wake up the cpus */
if (prcmu_copy_gic_settings())
goto out;
/* Check in the meantime an interrupt did
* not occur on the gic ... */
if (prcmu_gic_pending_irq())
goto out;
/* ... and the prcmu */
if (prcmu_pending_irq())
goto out;
/* Go to the retention state, the prcmu will wait for the
* cpu to go WFI and this is what happens after exiting this
* 'master' critical section */
if (prcmu_set_power_state(PRCMU_AP_IDLE, true, true))
goto out;
/* When we switch to retention, the prcmu is in charge
* of recoupling the gic automatically */
recouple = false;
spin_unlock(&master_lock);
}
wfi:
cpu_do_idle();
out:
atomic_dec(&master);
if (recouple) {
prcmu_gic_recouple();
spin_unlock(&master_lock);
}
return index;
}
static struct cpuidle_driver ux500_idle_driver = {
.name = "ux500_idle",
.owner = THIS_MODULE,
.states = {
ARM_CPUIDLE_WFI_STATE,
{
.enter = ux500_enter_idle,
.exit_latency = 70,
.target_residency = 260,
.flags = CPUIDLE_FLAG_TIME_VALID |
CPUIDLE_FLAG_TIMER_STOP,
.name = "ApIdle",
.desc = "ARM Retention",
},
},
.safe_state_index = 0,
.state_count = 2,
};
int __init ux500_idle_init(void)
{
/* Configure wake up reasons */
prcmu_enable_wakeups(PRCMU_WAKEUP(ARM) | PRCMU_WAKEUP(RTC) |
PRCMU_WAKEUP(ABB));
return cpuidle_register(&ux500_idle_driver, NULL);
}
device_initcall(ux500_idle_init);