From patchwork Fri Oct 24 23:40:21 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lina Iyer X-Patchwork-Id: 5150691 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 9114DC11AC for ; Fri, 24 Oct 2014 23:44:43 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 7DD602025B for ; Fri, 24 Oct 2014 23:44:42 +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 6554620256 for ; Fri, 24 Oct 2014 23:44:41 +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 1XhoV7-0006gC-MQ; Fri, 24 Oct 2014 23:42:33 +0000 Received: from mail-pd0-f177.google.com ([209.85.192.177]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XhoTu-00064c-Gb for linux-arm-kernel@lists.infradead.org; Fri, 24 Oct 2014 23:41:20 +0000 Received: by mail-pd0-f177.google.com with SMTP id v10so2257375pde.22 for ; Fri, 24 Oct 2014 16:40:57 -0700 (PDT) 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=sM2NL8fLpkhhuyHGtTTcACXMEgwMRzXarEr6tqpmhoQ=; b=KUv8RtID+oZww9eEd9yuFIJV8YrSa/5nLqMUR4/dEbXGNGKV/wT43WFbowJKJ3jOdH hWPdEtIDvaK+SE3F7JzcQ8BitDYeMmcJzOOAPxk105QPa7nGki9Ma6VWvlLH4GHLcHfw f9m8C6jqH9Y80TwFSo8gx/keDjpIoNj5kmaOGYBHOv8KWDENztaC3JijWF3IuoGCjx1V pFwN/Dll2r0mkGflz5InLKwZJQmiCVzfu5eRJvGl1wYDgYOtsGmhr1VEoi9yxH15MiKj SyMR0wumm/ayTVdwR9tKVBqbrIjG/WbuG1xXPYtQN61E1nLhOty85rj8JM0rQ2cOu+R7 SNAQ== X-Gm-Message-State: ALoCoQkrNIlAoqWBG1QxybySgyWRanwOFtHn6038aKnXAg3iGtx31fHWvWOD15ngpGa57hHbkGeQ X-Received: by 10.68.210.232 with SMTP id mx8mr7585669pbc.117.1414194057524; Fri, 24 Oct 2014 16:40:57 -0700 (PDT) Received: from ubuntu.localdomain (proxy6-global253.qualcomm.com. [199.106.103.253]) by mx.google.com with ESMTPSA id fm15sm4774620pdb.58.2014.10.24.16.40.55 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 24 Oct 2014 16:40:56 -0700 (PDT) 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 v9 6/9] qcom: cpuidle: Add cpuidle driver for QCOM cpus Date: Fri, 24 Oct 2014 17:40:21 -0600 Message-Id: <1414194024-55547-7-git-send-email-lina.iyer@linaro.org> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1414194024-55547-1-git-send-email-lina.iyer@linaro.org> References: <1414194024-55547-1-git-send-email-lina.iyer@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20141024_164118_637907_F20E5E43 X-CRM114-Status: GOOD ( 21.87 ) X-Spam-Score: -1.4 (-) 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=-3.3 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE, 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 C-States. Use the cpuidle DT interface, common across ARM architectures, to provide the C-State information to the cpuidle framework. Supported modes at this time are Standby and Standalone Power Collapse. Signed-off-by: Lina Iyer --- .../bindings/arm/msm/qcom,idle-state.txt | 81 ++++++++++++++++++++++ drivers/cpuidle/Kconfig.arm | 7 ++ drivers/cpuidle/Makefile | 1 + drivers/cpuidle/cpuidle-qcom.c | 72 +++++++++++++++++++ 4 files changed, 161 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..13c7c1f 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 QCOM_PM + 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..1c1dcbc --- /dev/null +++ b/drivers/cpuidle/cpuidle-qcom.c @@ -0,0 +1,72 @@ +/* + * 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) +{ + lpm_ops->standby(NULL); + + return index; +} + +static int qcom_cpu_spc(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int index) +{ + lpm_ops->spc(NULL); + + 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);