Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932188AbbFHKmN (ORCPT ); Mon, 8 Jun 2015 06:42:13 -0400 Received: from foss.arm.com ([217.140.101.70]:48093 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752728AbbFHKka (ORCPT ); Mon, 8 Jun 2015 06:40:30 -0400 From: Sudeep Holla To: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Sudeep Holla , Liviu Dudau , Lorenzo Pieralisi , "Jon Medhurst (Tixy)" , Arnd Bergmann , Kevin Hilman , Olof Johansson , Viresh Kumar , "Rafael J. Wysocki" Subject: [PATCH v4 5/8] cpufreq: arm_big_little: add SCPI interface driver Date: Mon, 8 Jun 2015 11:39:59 +0100 Message-Id: <1433760002-24120-6-git-send-email-sudeep.holla@arm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1433760002-24120-1-git-send-email-sudeep.holla@arm.com> References: <1433760002-24120-1-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: 5906 Lines: 190 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 Acked-by: Viresh Kumar 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 | 124 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 134 insertions(+) create mode 100644 drivers/cpufreq/scpi-cpufreq.c diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm index 611cb09239eb..6419b17b89dd 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 adds the CPUfreq driver support for ARM big.LITTLE platforms + using SCPI protocol for CPU power management. + + This driver uses SCPI Message Protocol driver to interact with the + firmware providing the CPU DVFS functionality. 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..2c3b16fd3a01 --- /dev/null +++ b/drivers/cpufreq/scpi-cpufreq.c @@ -0,0 +1,124 @@ +/* + * System Control and Power Interface (SCPI) based 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 struct scpi_dvfs_info *scpi_get_dvfs_info(struct device *cpu_dev) +{ + u8 domain = topology_physical_package_id(cpu_dev->id); + + if (domain < 0) + return ERR_PTR(-EINVAL); + return scpi_ops->dvfs_get_info(domain); +} + +static int scpi_opp_table_ops(struct device *cpu_dev, bool remove) +{ + int idx, ret = 0; + struct scpi_opp *opp; + struct scpi_dvfs_info *info = scpi_get_dvfs_info(cpu_dev); + + if (IS_ERR(info)) + return PTR_ERR(info); + + if (!info->opps) + return -EIO; + + for (opp = info->opps, idx = 0; idx < info->count; idx++, opp++) { + if (remove) + dev_pm_opp_remove(cpu_dev, opp->freq); + else + 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); + while (idx-- > 0) + dev_pm_opp_remove(cpu_dev, (--opp)->freq); + return ret; + } + } + return ret; +} + +static int scpi_get_transition_latency(struct device *cpu_dev) +{ + struct scpi_dvfs_info *info = scpi_get_dvfs_info(cpu_dev); + + if (IS_ERR(info)) + return PTR_ERR(info); + return info->latency; +} + +static int scpi_init_opp_table(struct device *cpu_dev) +{ + return scpi_opp_table_ops(cpu_dev, false); +} + +static void scpi_free_opp_table(struct device *cpu_dev) +{ + scpi_opp_table_ops(cpu_dev, true); +} + +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, + .free_opp_table = scpi_free_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); + scpi_ops = NULL; + 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_AUTHOR("Sudeep Holla "); +MODULE_DESCRIPTION("ARM SCPI CPUFreq interface driver"); +MODULE_LICENSE("GPL v2"); -- 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/