From patchwork Fri May 17 15:35:07 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicolas Saenz Julienne X-Patchwork-Id: 10948121 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BF1B31398 for ; Fri, 17 May 2019 15:35:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AE59E28358 for ; Fri, 17 May 2019 15:35:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A29D428384; Fri, 17 May 2019 15:35:28 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2E8B028358 for ; Fri, 17 May 2019 15:35:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729357AbfEQPfW (ORCPT ); Fri, 17 May 2019 11:35:22 -0400 Received: from mx2.suse.de ([195.135.220.15]:39188 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729344AbfEQPfU (ORCPT ); Fri, 17 May 2019 11:35:20 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id E2AC1ACF5; Fri, 17 May 2019 15:35:18 +0000 (UTC) From: Nicolas Saenz Julienne To: stefan.wahren@i2se.com, "Rafael J. Wysocki" , Viresh Kumar Cc: mbrugger@suse.de, sboyd@kernel.org, eric@anholt.net, f.fainelli@gmail.com, bcm-kernel-feedback-list@broadcom.com, ptesarik@suse.com, linux-rpi-kernel@lists.infradead.org, Nicolas Saenz Julienne , linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org Subject: [RFC 5/5] cpufreq: add driver for Raspbery Pi Date: Fri, 17 May 2019 17:35:07 +0200 Message-Id: <20190517153508.18314-6-nsaenzjulienne@suse.de> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190517153508.18314-1-nsaenzjulienne@suse.de> References: <20190517153508.18314-1-nsaenzjulienne@suse.de> MIME-Version: 1.0 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Raspberry Pi's firmware offers and interface though which update it's performance requirements. It allows us to request for specific runtime frequencies, which the firmware might or might not respect, depending on the firmware configuration and thermals. As the maximum and minimum frequencies are configurable in the firmware there is no way to know in advance their values. So the Raspberry Pi cpufreq driver queries them, builds an opp frequency table to then launch cpufreq-dt. Signed-off-by: Nicolas Saenz Julienne --- drivers/cpufreq/Kconfig.arm | 8 +++ drivers/cpufreq/Makefile | 1 + drivers/cpufreq/raspberrypi-cpufreq.c | 79 +++++++++++++++++++++++++++ 3 files changed, 88 insertions(+) create mode 100644 drivers/cpufreq/raspberrypi-cpufreq.c diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm index 179a1d302f48..70e5f13f7632 100644 --- a/drivers/cpufreq/Kconfig.arm +++ b/drivers/cpufreq/Kconfig.arm @@ -308,3 +308,11 @@ config ARM_PXA2xx_CPUFREQ This add the CPUFreq driver support for Intel PXA2xx SOCs. If in doubt, say N. + +config ARM_RASPBERRYPI_CPUFREQ + tristate "Raspberry Pi cpufreq support" + depends on RASPBERRYPI_FIRMWARE || (RASPBERRYPI_FIRMWARE=n && COMPILE_TEST) + help + This adds the CPUFreq driver for Raspberry Pi + + If in doubt, say N. diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile index 689b26c6f949..02678e9b2ff5 100644 --- a/drivers/cpufreq/Makefile +++ b/drivers/cpufreq/Makefile @@ -84,6 +84,7 @@ obj-$(CONFIG_ARM_TEGRA124_CPUFREQ) += tegra124-cpufreq.o obj-$(CONFIG_ARM_TEGRA186_CPUFREQ) += tegra186-cpufreq.o obj-$(CONFIG_ARM_TI_CPUFREQ) += ti-cpufreq.o obj-$(CONFIG_ARM_VEXPRESS_SPC_CPUFREQ) += vexpress-spc-cpufreq.o +obj-$(CONFIG_ARM_RASPBERRYPI_CPUFREQ) += raspberrypi-cpufreq.o ################################################################################## diff --git a/drivers/cpufreq/raspberrypi-cpufreq.c b/drivers/cpufreq/raspberrypi-cpufreq.c new file mode 100644 index 000000000000..53cb3e5a8457 --- /dev/null +++ b/drivers/cpufreq/raspberrypi-cpufreq.c @@ -0,0 +1,79 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Raspberry Pi cpufreq driver + * + * Copyright (C) 2019, Nicolas Saenz Julienne + */ + +#include +#include +#include +#include +#include +#include +#include + +static const struct of_device_id machines[] __initconst = { + { .compatible = "raspberrypi,3-model-b-plus" }, + { .compatible = "raspberrypi,3-model-b" }, + { /* sentinel */ } +}; + +static int __init raspberrypi_cpufreq_driver_init(void) +{ + struct platform_device *pdev; + struct cpumask shared_cpus; + struct device *cpu_dev; + struct clk *clk; + long min, max; + long rate; + int ret; + + if (!of_match_node(machines, of_root)) + return -ENODEV; + + cpu_dev = get_cpu_device(0); + if (!cpu_dev) { + pr_err("Cannot get CPU for cpufreq driver\n"); + return -ENODEV; + } + + clk = clk_get(cpu_dev, 0); + if (IS_ERR(clk)) { + dev_err(cpu_dev, "Cannot get clock for CPU0\n"); + return PTR_ERR(clk); + } + + /* + * The max and min frequencies are configurable in the Raspberry Pi + * firmware, so we query them at runtime + */ + min = clk_round_rate(clk, 0); + max = clk_round_rate(clk, ULONG_MAX); + + for (rate = min; rate < max; rate += 100000000) { + ret = dev_pm_opp_add(cpu_dev, rate, 0); + if (ret) + return ret; + } + + ret = dev_pm_opp_add(cpu_dev, max, 0); + if (ret) + return ret; + + cpumask_setall(&shared_cpus); + dev_pm_opp_set_sharing_cpus(cpu_dev, &shared_cpus); + + pdev = platform_device_register_data(NULL, "cpufreq-dt", -1, NULL, 0); + ret = PTR_ERR_OR_ZERO(pdev); + if (ret) + dev_err(cpu_dev, "Failed to create platform device, %d\n", ret); + + return ret; +} + +late_initcall(raspberrypi_cpufreq_driver_init); + +MODULE_AUTHOR("Nicolas Saenz Julienne