From patchwork Thu Apr 19 12:46:32 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Lezcano X-Patchwork-Id: 7947 Return-Path: X-Original-To: patchwork@peony.canonical.com Delivered-To: patchwork@peony.canonical.com Received: from fiordland.canonical.com (fiordland.canonical.com [91.189.94.145]) by peony.canonical.com (Postfix) with ESMTP id C9AA323E13 for ; Thu, 19 Apr 2012 12:46:36 +0000 (UTC) Received: from mail-iy0-f180.google.com (mail-iy0-f180.google.com [209.85.210.180]) by fiordland.canonical.com (Postfix) with ESMTP id 6F3E4A18074 for ; Thu, 19 Apr 2012 12:46:36 +0000 (UTC) Received: by iage36 with SMTP id e36so16250305iag.11 for ; Thu, 19 Apr 2012 05:46:35 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=x-forwarded-to:x-forwarded-for:delivered-to:received-spf:from:to:cc :subject:date:message-id:x-mailer:x-gm-message-state; bh=MICadELNP2XC148dnbtg97plbbLx3Jb5rrDkVoruSAA=; b=JWCMqvGw884Q2ogNhPL0rkCrT644R8/Z4ZlwX5H0yzj1Vafn2OAO5tiZA1YmoGlu57 ix4zK+vjudqPyi/bHyVkIVY5u7XF9U2KXtpIMVFualMcCHu1YQfi2M95ing2WUorKKCM v7ZwPeET40A9cQi9s06/ZdIM6qlP5I7TJLj4DO4tu0CO4nPclDPFvUBZXfFmBuW/1D0J lRVmtK4M0VZo3gXP5jy3Rs+m3X4eBB5oOxDYE5+zAwjARUxl+xgQ5Zk3I1Q63m48sxz5 VwHMDvS8UlXtyuHFF9VQf79d69sOMCpzmqWVkc1Sa3cso828+E/Q+j+nykwpbxH2K6dD Y2+Q== Received: by 10.50.10.201 with SMTP id k9mr1791133igb.55.1334839595875; Thu, 19 Apr 2012 05:46:35 -0700 (PDT) X-Forwarded-To: linaro-patchwork@canonical.com X-Forwarded-For: patch@linaro.org linaro-patchwork@canonical.com Delivered-To: patches@linaro.org Received: by 10.231.137.198 with SMTP id x6csp287443ibt; Thu, 19 Apr 2012 05:46:35 -0700 (PDT) Received: by 10.180.97.4 with SMTP id dw4mr25939210wib.18.1334839594677; Thu, 19 Apr 2012 05:46:34 -0700 (PDT) Received: from mail-wg0-f50.google.com (mail-wg0-f50.google.com [74.125.82.50]) by mx.google.com with ESMTPS id u68si2210109wei.41.2012.04.19.05.46.34 (version=TLSv1/SSLv3 cipher=OTHER); Thu, 19 Apr 2012 05:46:34 -0700 (PDT) Received-SPF: neutral (google.com: 74.125.82.50 is neither permitted nor denied by best guess record for domain of daniel.lezcano@linaro.org) client-ip=74.125.82.50; Authentication-Results: mx.google.com; spf=neutral (google.com: 74.125.82.50 is neither permitted nor denied by best guess record for domain of daniel.lezcano@linaro.org) smtp.mail=daniel.lezcano@linaro.org Received: by wgbds12 with SMTP id ds12so8281394wgb.31 for ; Thu, 19 Apr 2012 05:46:34 -0700 (PDT) Received: by 10.180.95.197 with SMTP id dm5mr25899290wib.20.1334839593946; Thu, 19 Apr 2012 05:46:33 -0700 (PDT) Received: from localhost.localdomain (AToulouse-651-1-95-48.w90-16.abo.wanadoo.fr. [90.16.214.48]) by mx.google.com with ESMTPS id e6sm42050714wix.8.2012.04.19.05.46.32 (version=TLSv1/SSLv3 cipher=OTHER); Thu, 19 Apr 2012 05:46:33 -0700 (PDT) From: Daniel Lezcano To: linus.walleij@linaro.org, lenb@kernel.org Cc: rickard.andersson@stericsson.com, linux-arm-kernel@lists.infradead.org, linaro-dev@lists.linaro.org, patches@linaro.org Subject: [PATCH] ARM: ux500: add the cpuidle driver for WFI and ARM retention Date: Thu, 19 Apr 2012 14:46:32 +0200 Message-Id: <1334839592-32251-1-git-send-email-daniel.lezcano@linaro.org> X-Mailer: git-send-email 1.7.5.4 X-Gm-Message-State: ALoCoQlDdOKmshxBAV8WNmvQBWYtNpEiwYPgDPY+uuuXIC5ygxqcLYQNvhiH0HaC5WxP9tQgKTuN This patch adds the cpuidle driver for the ux500 SoC. The boards saves 12mA with these states. It is based on the latest cpuidle consolidation from Robert Lee. The cpu can go to retention only if the other core is in WFI. If the other cpu is in WFI and we decoupled the gic from the cores, then we have the guarantee, it won't be wake up. It is up to the prcmu firmware to recouple the gic automatically after the power state mode is selected. Signed-off-by: Daniel Lezcano --- arch/arm/mach-ux500/Makefile | 1 + arch/arm/mach-ux500/cpuidle.c | 171 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 172 insertions(+), 0 deletions(-) create mode 100644 arch/arm/mach-ux500/cpuidle.c diff --git a/arch/arm/mach-ux500/Makefile b/arch/arm/mach-ux500/Makefile index fc7db5d..3b86b61 100644 --- a/arch/arm/mach-ux500/Makefile +++ b/arch/arm/mach-ux500/Makefile @@ -4,6 +4,7 @@ obj-y := clock.o cpu.o devices.o devices-common.o \ id.o usb.o timer.o +obj-$(CONFIG_CPU_IDLE) += cpuidle.o obj-$(CONFIG_CACHE_L2X0) += cache-l2x0.o obj-$(CONFIG_UX500_SOC_DB8500) += cpu-db8500.o devices-db8500.o obj-$(CONFIG_MACH_MOP500) += board-mop500.o board-mop500-sdi.o \ diff --git a/arch/arm/mach-ux500/cpuidle.c b/arch/arm/mach-ux500/cpuidle.c new file mode 100644 index 0000000..b54884bd --- /dev/null +++ b/arch/arm/mach-ux500/cpuidle.c @@ -0,0 +1,171 @@ +/* + * Copyright (c) 2012 Linaro : Daniel Lezcano (IBM) + * + * Based on the work of Rickard Andersson + * and Jonas Aaberg . + * + * 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 +#include +#include +#include +#include +#include +#include + +#include +#include + +static atomic_t master = ATOMIC_INIT(0); +static DEFINE_SPINLOCK(master_lock); +static DEFINE_PER_CPU(struct cpuidle_device, ux500_cpuidle_device); + +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; + + clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &this_cpu); + + 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()) + 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); + } + + clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &this_cpu); + + return index; +} + +static struct cpuidle_driver ux500_idle_driver = { + .name = "ux500_idle", + .owner = THIS_MODULE, + .en_core_tk_irqen = 1, + .states = { + ARM_CPUIDLE_WFI_STATE, + { + .enter = ux500_enter_idle, + .exit_latency = 70, + .target_residency = 260, + .flags = CPUIDLE_FLAG_TIME_VALID, + .name = "ApIdle", + .desc = "ARM Retention", + }, + }, + .safe_state_index = 0, + .state_count = 2, +}; + +/* + * For each cpu, setup the broadcast timer because we will + * need to migrate the timers for the states >= ApIdle. + */ +static void ux500_setup_broadcast_timer(void *arg) +{ + int cpu = smp_processor_id(); + clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ON, &cpu); +} + +int __init ux500_idle_init(void) +{ + int ret, cpu; + struct cpuidle_device *device; + + /* Configure wake up reasons */ + prcmu_enable_wakeups(PRCMU_WAKEUP(ARM) | PRCMU_WAKEUP(RTC) | + PRCMU_WAKEUP(ABB)); + + /* + * Configure the timer broadcast for each cpu, that must + * be done from the cpu context, so we use a smp cross + * call with 'on_each_cpu'. + */ + on_each_cpu(ux500_setup_broadcast_timer, NULL, 1); + + ret = cpuidle_register_driver(&ux500_idle_driver); + if (ret) { + printk(KERN_ERR "failed to register ux500 idle driver\n"); + return ret; + } + + for_each_online_cpu(cpu) { + device = &per_cpu(ux500_cpuidle_device, cpu); + device->cpu = cpu; + ret = cpuidle_register_device(device); + if (ret) { + printk(KERN_ERR "Failed to register cpuidle " + "device for cpu%d\n", cpu); + goto out_unregister; + } + } +out: + return ret; + +out_unregister: + for_each_online_cpu(cpu) { + device = &per_cpu(ux500_cpuidle_device, cpu); + cpuidle_unregister_device(device); + } + + cpuidle_unregister_driver(&ux500_idle_driver); + goto out; +} + +device_initcall(ux500_idle_init);