From patchwork Tue Jun 4 17:32:25 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: 10975861 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 053E33E8C for ; Tue, 4 Jun 2019 17:40:14 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E63D72842B for ; Tue, 4 Jun 2019 17:40:13 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D9EDA284F1; Tue, 4 Jun 2019 17:40:13 +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=unavailable 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 736EE286BE for ; Tue, 4 Jun 2019 17:40:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726179AbfFDRkM (ORCPT ); Tue, 4 Jun 2019 13:40:12 -0400 Received: from mx2.suse.de ([195.135.220.15]:40990 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725933AbfFDRkM (ORCPT ); Tue, 4 Jun 2019 13:40:12 -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 72B2CAE05; Tue, 4 Jun 2019 17:40:10 +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, ssuloev@orpaltech.com, linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org, mturquette@baylibre.com, linux-pm@vger.kernel.org, Nicolas Saenz Julienne , linux-kernel@vger.kernel.org Subject: [PATCH 4/4] cpufreq: add driver for Raspbery Pi Date: Tue, 4 Jun 2019 19:32:25 +0200 Message-Id: <20190604173223.4229-5-nsaenzjulienne@suse.de> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190604173223.4229-1-nsaenzjulienne@suse.de> References: <20190604173223.4229-1-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 --- Changes since RFC: - Alphabetically ordered relevant stuff - Updated Kconfig to select firmware interface - Correctly unref clk_dev after use - Remove all opps on failure - Remove use of dev_pm_opp_set_sharing_cpus() drivers/cpufreq/Kconfig.arm | 8 +++ drivers/cpufreq/Makefile | 1 + drivers/cpufreq/raspberrypi-cpufreq.c | 84 +++++++++++++++++++++++++++ 3 files changed, 93 insertions(+) create mode 100644 drivers/cpufreq/raspberrypi-cpufreq.c diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm index f8129edc145e..556d432cc826 100644 --- a/drivers/cpufreq/Kconfig.arm +++ b/drivers/cpufreq/Kconfig.arm @@ -133,6 +133,14 @@ config ARM_QCOM_CPUFREQ_HW The driver implements the cpufreq interface for this HW engine. Say Y if you want to support CPUFreq HW. +config ARM_RASPBERRYPI_CPUFREQ + tristate "Raspberry Pi cpufreq support" + select RASPBERRYPI_FIRMWARE + help + This adds the CPUFreq driver for Raspberry Pi + + If in doubt, say N. + config ARM_S3C_CPUFREQ bool help diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile index 689b26c6f949..121c1acb66c0 100644 --- a/drivers/cpufreq/Makefile +++ b/drivers/cpufreq/Makefile @@ -64,6 +64,7 @@ obj-$(CONFIG_ARM_PXA2xx_CPUFREQ) += pxa2xx-cpufreq.o obj-$(CONFIG_PXA3xx) += pxa3xx-cpufreq.o obj-$(CONFIG_ARM_QCOM_CPUFREQ_HW) += qcom-cpufreq-hw.o obj-$(CONFIG_ARM_QCOM_CPUFREQ_KRYO) += qcom-cpufreq-kryo.o +obj-$(CONFIG_ARM_RASPBERRYPI_CPUFREQ) += raspberrypi-cpufreq.o obj-$(CONFIG_ARM_S3C2410_CPUFREQ) += s3c2410-cpufreq.o obj-$(CONFIG_ARM_S3C2412_CPUFREQ) += s3c2412-cpufreq.o obj-$(CONFIG_ARM_S3C2416_CPUFREQ) += s3c2416-cpufreq.o diff --git a/drivers/cpufreq/raspberrypi-cpufreq.c b/drivers/cpufreq/raspberrypi-cpufreq.c new file mode 100644 index 000000000000..2b3a195a9d37 --- /dev/null +++ b/drivers/cpufreq/raspberrypi-cpufreq.c @@ -0,0 +1,84 @@ +// 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" }, + { .compatible = "raspberrypi,2-model-b" }, + { /* sentinel */ } +}; + +static int __init raspberrypi_cpufreq_driver_init(void) +{ + struct platform_device *pdev; + struct device *cpu_dev; + unsigned long min, max; + unsigned long rate; + struct clk *clk; + 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); + clk_put(clk); + + for (rate = min; rate < max; rate += 100000000) { + ret = dev_pm_opp_add(cpu_dev, rate, 0); + if (ret) + goto remove_opp; + } + + ret = dev_pm_opp_add(cpu_dev, max, 0); + if (ret) + goto remove_opp; + + 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); + goto remove_opp; + } + + return 0; + +remove_opp: + dev_pm_opp_remove_all_dynamic(cpu_dev); + + return ret; +} + +late_initcall(raspberrypi_cpufreq_driver_init); + +MODULE_AUTHOR("Nicolas Saenz Julienne