From patchwork Wed Nov 26 22:28:27 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lina Iyer X-Patchwork-Id: 5389241 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id B91D79F2F5 for ; Wed, 26 Nov 2014 22:34:13 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 83254201EC for ; Wed, 26 Nov 2014 22:34:12 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C223B201FB for ; Wed, 26 Nov 2014 22:34:10 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1Xtl7N-0000Zg-8U; Wed, 26 Nov 2014 22:31:25 +0000 Received: from mail-pd0-f180.google.com ([209.85.192.180]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Xtl5H-0006zN-5c for linux-arm-kernel@lists.infradead.org; Wed, 26 Nov 2014 22:29:16 +0000 Received: by mail-pd0-f180.google.com with SMTP id p10so3599327pdj.25 for ; Wed, 26 Nov 2014 14:28:59 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=2Gt2D1l1kpD+uEapTAO9n/R7k408Kfjk73HPIIpj3uc=; b=c4fRICGE6RRggIO7AHvVY/ZYepmQig7mqVtKlrXQeZlqZgiqxIj/aOJu1mLeMZA2Mx D4oMgPrSMUl1cUQBxmJJcopFUDy1irqs3EtuPVBKZiPEOQFoavxLn82gmJnk3dKECSeU rfs9DQhPvRs8vNoQ8ThmBpxV4dqbxPmqJihtOD8C83mFb1GWRovTcXZFMvFluKTRgI2I U8ODckkkTG673ainfimKR1R5BBDwuSo6BiMGZM/6q29PHznUcyfsoCQddedIaO/VQk75 51AqgVNDghHgdQAJTFqqzpfIm+bGonNfkix/lyAxFb7wCZ0OwIovgOYgvfiODYrSZ/Gd a9jw== X-Gm-Message-State: ALoCoQlwwNz9w/wyW239aIf3sBe2XqPjiA2Ma+Un2qDKtPD0ysbe9jLJcVlGuRoMnIvv2Syq8e1W X-Received: by 10.66.160.230 with SMTP id xn6mr6647744pab.145.1417040938811; Wed, 26 Nov 2014 14:28:58 -0800 (PST) Received: from ubuntu.localdomain (proxy6-global253.qualcomm.com. [199.106.103.253]) by mx.google.com with ESMTPSA id xd3sm5219025pbc.54.2014.11.26.14.28.56 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 26 Nov 2014 14:28:58 -0800 (PST) From: Lina Iyer To: daniel.lezcano@linaro.org, khilman@linaro.org, sboyd@codeaurora.org, galak@codeaurora.org, linux-arm-msm@vger.kernel.org, linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH 07/10] qcom: cpuidle: Add cpuidle driver for QCOM cpus Date: Wed, 26 Nov 2014 15:28:27 -0700 Message-Id: <1417040910-43290-8-git-send-email-lina.iyer@linaro.org> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1417040910-43290-1-git-send-email-lina.iyer@linaro.org> References: <1417040910-43290-1-git-send-email-lina.iyer@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20141126_142915_287790_C69AB5ED X-CRM114-Status: GOOD ( 22.53 ) X-Spam-Score: -0.7 (/) Cc: msivasub@codeaurora.org, devicetree@vger.kernel.org, lorenzo.pieralisi@arm.com, Lina Iyer X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_LOW, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Add cpuidle driver interface to allow cpus to go into idle states. Use the cpuidle DT interface, common across ARM architectures, to provide the idle state information to the cpuidle framework. Supported modes at this time are Standby and Standalone Power Collapse. Signed-off-by: Lina Iyer Acked-by: Daniel Lezcano Acked-by: Lorenzo Pieralisi --- .../bindings/arm/msm/qcom,idle-state.txt | 81 ++++++++++++++++++++++ drivers/cpuidle/Kconfig.arm | 7 ++ drivers/cpuidle/Makefile | 1 + drivers/cpuidle/cpuidle-qcom.c | 74 ++++++++++++++++++++ 4 files changed, 163 insertions(+) create mode 100644 Documentation/devicetree/bindings/arm/msm/qcom,idle-state.txt create mode 100644 drivers/cpuidle/cpuidle-qcom.c diff --git a/Documentation/devicetree/bindings/arm/msm/qcom,idle-state.txt b/Documentation/devicetree/bindings/arm/msm/qcom,idle-state.txt new file mode 100644 index 0000000..ae1b07f --- /dev/null +++ b/Documentation/devicetree/bindings/arm/msm/qcom,idle-state.txt @@ -0,0 +1,81 @@ +QCOM Idle States for cpuidle driver + +ARM provides idle-state node to define the cpuidle states, as defined in [1]. +cpuidle-qcom is the cpuidle driver for Qualcomm SoCs and uses these idle +states. Idle states have different enter/exit latency and residency values. +The idle states supported by the QCOM SoC are defined as - + + * Standby + * Retention + * Standalone Power Collapse (Standalone PC or SPC) + * Power Collapse (PC) + +Standby: Standby does a little more in addition to architectural clock gating. +When the WFI instruction is executed the ARM core would gate its internal +clocks. In addition to gating the clocks, QCOM cpus use this instruction as a +trigger to execute the SPM state machine. The SPM state machine waits for the +interrupt to trigger the core back in to active. This triggers the cache +hierarchy to enter standby states, when all cpus are idle. An interrupt brings +the SPM state machine out of its wait, the next step is to ensure that the +cache hierarchy is also out of standby, and then the cpu is allowed to resume +execution. + +Retention: Retention is a low power state where the core is clock gated and +the memory and the registers associated with the core are retained. The +voltage may be reduced to the minimum value needed to keep the processor +registers active. The SPM should be configured to execute the retention +sequence and would wait for interrupt, before restoring the cpu to execution +state. Retention may have a slightly higher latency than Standby. + +Standalone PC: A cpu can power down and warmboot if there is a sufficient time +between the time it enters idle and the next known wake up. SPC mode is used +to indicate a core entering a power down state without consulting any other +cpu or the system resources. This helps save power only on that core. The SPM +sequence for this idle state is programmed to power down the supply to the +core, wait for the interrupt, restore power to the core, and ensure the +system state including cache hierarchy is ready before allowing core to +resume. Applying power and resetting the core causes the core to warmboot +back into Elevation Level (EL) which trampolines the control back to the +kernel. Entering a power down state for the cpu, needs to be done by trapping +into a EL. Failing to do so, would result in a crash enforced by the warm boot +code in the EL for the SoC. On SoCs with write-back L1 cache, the cache has to +be flushed in s/w, before powering down the core. + +Power Collapse: This state is similar to the SPC mode, but distinguishes +itself in that the cpu acknowledges and permits the SoC to enter deeper sleep +modes. In a hierarchical power domain SoC, this means L2 and other caches can +be flushed, system bus, clocks - lowered, and SoC main XO clock gated and +voltages reduced, provided all cpus enter this state. Since the span of low +power modes possible at this state is vast, the exit latency and the residency +of this low power mode would be considered high even though at a cpu level, +this essentially is cpu power down. The SPM in this state also may handshake +with the Resource power manager processor in the SoC to indicate a complete +application processor subsystem shut down. + +The idle-state for QCOM SoCs are distinguished by the compatible property of +the idle-states device node. +The devicetree representation of the idle state should be - + +Required properties: + +- compatible: Must be one of - + "qcom,idle-state-stby", + "qcom,idle-state-ret", + "qcom,idle-state-spc", + "qcom,idle-state-pc", + and "arm,idle-state". + +Other required and optional properties are specified in [1]. + +Example: + + idle-states { + CPU_SPC: spc { + compatible = "qcom,idle-state-spc", "arm,idle-state"; + entry-latency-us = <150>; + exit-latency-us = <200>; + min-residency-us = <2000>; + }; + }; + +[1]. Documentation/devicetree/bindings/arm/idle-states.txt diff --git a/drivers/cpuidle/Kconfig.arm b/drivers/cpuidle/Kconfig.arm index 8c16ab2..e98993c 100644 --- a/drivers/cpuidle/Kconfig.arm +++ b/drivers/cpuidle/Kconfig.arm @@ -63,3 +63,10 @@ config ARM_MVEBU_V7_CPUIDLE depends on ARCH_MVEBU help Select this to enable cpuidle on Armada 370, 38x and XP processors. + +config ARM_QCOM_CPUIDLE + bool "CPU Idle drivers for Qualcomm processors" + depends on ARCH_QCOM + select DT_IDLE_STATES + help + Select this to enable cpuidle for QCOM processors diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile index 4d177b9..6c222d5 100644 --- a/drivers/cpuidle/Makefile +++ b/drivers/cpuidle/Makefile @@ -17,6 +17,7 @@ obj-$(CONFIG_ARM_ZYNQ_CPUIDLE) += cpuidle-zynq.o obj-$(CONFIG_ARM_U8500_CPUIDLE) += cpuidle-ux500.o obj-$(CONFIG_ARM_AT91_CPUIDLE) += cpuidle-at91.o obj-$(CONFIG_ARM_EXYNOS_CPUIDLE) += cpuidle-exynos.o +obj-$(CONFIG_ARM_QCOM_CPUIDLE) += cpuidle-qcom.o ############################################################################### # MIPS drivers diff --git a/drivers/cpuidle/cpuidle-qcom.c b/drivers/cpuidle/cpuidle-qcom.c new file mode 100644 index 0000000..bb383bb --- /dev/null +++ b/drivers/cpuidle/cpuidle-qcom.c @@ -0,0 +1,74 @@ +/* + * Copyright (c) 2014, Linaro Limited. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +#include +#include +#include + +#include +#include "dt_idle_states.h" + +static struct qcom_cpu_pm_ops *lpm_ops; + +static int qcom_cpu_stby(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int index) +{ + if (!lpm_ops->standby(NULL)) + return -1; + + return index; +} + +static int qcom_cpu_spc(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int index) +{ + if (!lpm_ops->spc(NULL)) + return -1; + + return index; +} + +static struct cpuidle_driver qcom_cpuidle_driver = { + .name = "qcom_cpuidle", +}; + +static const struct of_device_id qcom_idle_state_match[] = { + { .compatible = "qcom,idle-state-stby", .data = qcom_cpu_stby }, + { .compatible = "qcom,idle-state-spc", .data = qcom_cpu_spc }, + { }, +}; + +static int qcom_cpuidle_probe(struct platform_device *pdev) +{ + struct cpuidle_driver *drv = &qcom_cpuidle_driver; + int ret; + + lpm_ops = pdev->dev.platform_data; + + /* Probe for other states, including standby */ + ret = dt_init_idle_driver(drv, qcom_idle_state_match, 0); + if (ret < 0) + return ret; + + return cpuidle_register(drv, NULL); +} + +static struct platform_driver qcom_cpuidle_plat_driver = { + .probe = qcom_cpuidle_probe, + .driver = { + .name = "qcom_cpuidle", + }, +}; + +module_platform_driver(qcom_cpuidle_plat_driver);