Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932891AbbD0LlP (ORCPT ); Mon, 27 Apr 2015 07:41:15 -0400 Received: from foss.arm.com ([217.140.101.70]:56444 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932869AbbD0LlL (ORCPT ); Mon, 27 Apr 2015 07:41:11 -0400 From: Sudeep Holla To: linux-kernel@vger.kernel.org Cc: Sudeep Holla , Liviu Dudau , Lorenzo Pieralisi , "Jon Medhurst (Tixy)" , Viresh Kumar , "Rafael J. Wysocki" , linux-pm@vger.kernel.org Subject: [PATCH 4/4] cpufreq: arm_big_little: add SCPI interface driver Date: Mon, 27 Apr 2015 12:40:46 +0100 Message-Id: <1430134846-24320-5-git-send-email-sudeep.holla@arm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1430134846-24320-1-git-send-email-sudeep.holla@arm.com> References: <1430134846-24320-1-git-send-email-sudeep.holla@arm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5211 Lines: 168 On some ARM based systems, a separate Cortex-M based System Control Processor(SCP) provides the overall power, clock, reset and system control including CPU DVFS. SCPI Message Protocol is used to communicate with the SCPI. This patch adds a interface driver for adding OPPs and registering the arm_big_little cpufreq driver for such systems. Signed-off-by: Sudeep Holla Cc: Viresh Kumar Cc: "Rafael J. Wysocki" Cc: linux-pm@vger.kernel.org --- drivers/cpufreq/Kconfig.arm | 9 ++++ drivers/cpufreq/Makefile | 1 + drivers/cpufreq/scpi-cpufreq.c | 103 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 113 insertions(+) create mode 100644 drivers/cpufreq/scpi-cpufreq.c diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm index 4f3dbc8cf729..9e678bf1687c 100644 --- a/drivers/cpufreq/Kconfig.arm +++ b/drivers/cpufreq/Kconfig.arm @@ -24,6 +24,15 @@ config ARM_VEXPRESS_SPC_CPUFREQ This add the CPUfreq driver support for Versatile Express big.LITTLE platforms using SPC for power management. +config ARM_SCPI_CPUFREQ + tristate "SCPI based CPUfreq driver" + depends on ARM_BIG_LITTLE_CPUFREQ && ARM_SCPI_PROTOCOL + help + This add the CPUfreq driver support for ARM big.LITTLE platforms + using SCPI interface for CPU power management. + + This driver works only if firmware the supporting CPU DVFS adhere + to SCPI protocol. config ARM_EXYNOS_CPUFREQ tristate "SAMSUNG EXYNOS CPUfreq Driver" diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile index cdce92ae2e8b..02fc9f849d4b 100644 --- a/drivers/cpufreq/Makefile +++ b/drivers/cpufreq/Makefile @@ -79,6 +79,7 @@ obj-$(CONFIG_ARM_SA1110_CPUFREQ) += sa1110-cpufreq.o obj-$(CONFIG_ARM_SPEAR_CPUFREQ) += spear-cpufreq.o obj-$(CONFIG_ARM_TEGRA_CPUFREQ) += tegra-cpufreq.o obj-$(CONFIG_ARM_VEXPRESS_SPC_CPUFREQ) += vexpress-spc-cpufreq.o +obj-$(CONFIG_ARM_SCPI_CPUFREQ) += scpi-cpufreq.o ################################################################################## # PowerPC platform drivers diff --git a/drivers/cpufreq/scpi-cpufreq.c b/drivers/cpufreq/scpi-cpufreq.c new file mode 100644 index 000000000000..4c2c11a9dfc6 --- /dev/null +++ b/drivers/cpufreq/scpi-cpufreq.c @@ -0,0 +1,103 @@ +/* + * SCPI CPUFreq Interface driver + * + * It provides necessary ops to arm_big_little cpufreq driver. + * + * Copyright (C) 2015 ARM Ltd. + * Sudeep Holla + * + * 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. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include + +#include "arm_big_little.h" + +static struct scpi_ops *scpi_ops; + +static int scpi_init_opp_table(struct device *cpu_dev) +{ + u8 domain = topology_physical_package_id(cpu_dev->id); + struct scpi_dvfs_info *info; + struct scpi_opp *opp; + int idx, ret = 0; + + if ((dev_pm_opp_get_opp_count(cpu_dev)) > 0) + return 0; + info = scpi_ops->dvfs_get_info(domain); + if (IS_ERR(info)) + return PTR_ERR(info); + + opp = info->opps; + if (!opp) + return -EIO; + + for (idx = 0; idx < info->count; idx++, opp++) { + ret = dev_pm_opp_add(cpu_dev, opp->freq, opp->m_volt * 1000); + if (ret) { + dev_warn(cpu_dev, "failed to add opp %uHz %umV\n", + opp->freq, opp->m_volt); + return ret; + } + } + return ret; +} + +static int scpi_get_transition_latency(struct device *cpu_dev) +{ + u8 domain = topology_physical_package_id(cpu_dev->id); + struct scpi_dvfs_info *info; + + info = scpi_ops->dvfs_get_info(domain); + if (IS_ERR(info)) + return PTR_ERR(info); + + return info->latency; +} + +static struct cpufreq_arm_bL_ops scpi_cpufreq_ops = { + .name = "scpi", + .get_transition_latency = scpi_get_transition_latency, + .init_opp_table = scpi_init_opp_table, +}; + +static int scpi_cpufreq_probe(struct platform_device *pdev) +{ + scpi_ops = get_scpi_ops(); + if (!scpi_ops) + return -EIO; + + return bL_cpufreq_register(&scpi_cpufreq_ops); +} + +static int scpi_cpufreq_remove(struct platform_device *pdev) +{ + bL_cpufreq_unregister(&scpi_cpufreq_ops); + return 0; +} + +static struct platform_driver scpi_cpufreq_platdrv = { + .driver = { + .name = "scpi-cpufreq", + .owner = THIS_MODULE, + }, + .probe = scpi_cpufreq_probe, + .remove = scpi_cpufreq_remove, +}; +module_platform_driver(scpi_cpufreq_platdrv); + +MODULE_LICENSE("GPL"); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/