From patchwork Thu Jul 10 21:42:48 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tuomas Tynkkynen X-Patchwork-Id: 4527181 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 8DC009F1C4 for ; Thu, 10 Jul 2014 21:50:25 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 8512B2012E for ; Thu, 10 Jul 2014 21:50:24 +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 B51A5200F4 for ; Thu, 10 Jul 2014 21:50:22 +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 1X5MCL-0006zj-C2; Thu, 10 Jul 2014 21:48:13 +0000 Received: from hqemgate15.nvidia.com ([216.228.121.64]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1X5M8b-0007Bq-78 for linux-arm-kernel@lists.infradead.org; Thu, 10 Jul 2014 21:44:22 +0000 Received: from hqnvupgp07.nvidia.com (Not Verified[216.228.121.13]) by hqemgate15.nvidia.com id ; Thu, 10 Jul 2014 14:43:26 -0700 Received: from hqemhub03.nvidia.com ([172.20.12.94]) by hqnvupgp07.nvidia.com (PGP Universal service); Thu, 10 Jul 2014 14:33:01 -0700 X-PGP-Universal: processed; by hqnvupgp07.nvidia.com on Thu, 10 Jul 2014 14:33:01 -0700 Received: from ttynkkynen-lnx.Nvidia.com (172.20.144.16) by hqemhub03.nvidia.com (172.20.150.15) with Microsoft SMTP Server id 8.3.342.0; Thu, 10 Jul 2014 14:43:56 -0700 From: Tuomas Tynkkynen To: , , , Subject: [PATCH 12/13] cpufreq: Add cpufreq driver for Tegra124 Date: Fri, 11 Jul 2014 00:42:48 +0300 Message-ID: <1405028569-14253-13-git-send-email-ttynkkynen@nvidia.com> X-Mailer: git-send-email 1.8.1.5 In-Reply-To: <1405028569-14253-1-git-send-email-ttynkkynen@nvidia.com> References: <1405028569-14253-1-git-send-email-ttynkkynen@nvidia.com> X-NVConfidentiality: public MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140710_144421_527118_57EF9248 X-CRM114-Status: GOOD ( 20.51 ) X-Spam-Score: -0.7 (/) Cc: devicetree@vger.kernel.org, Prashant Gaikwad , Mike Turquette , Stephen Warren , Viresh Kumar , Peter De Schrijver , "Rafael J. Wysocki" , Thierry Reding , Tuomas Tynkkynen 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,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 a new cpufreq driver for Tegra124. Instead of using the PLLX as the CPU clocksource, switch immediately to the DFLL. It allows the use of higher clock rates, and will automatically scale the CPU voltage as well. We also rely on the DFLL driver to determine the CPU clock frequencies that the chip supports, so that we can directly build a cpufreq table with the OPP library helper dev_pm_opp_init_cpufreq_table. This driver is a completely independent of the old cpufreq driver (tegra-cpufreq), which is only used on Tegra20. Signed-off-by: Tuomas Tynkkynen --- A platform_driver_register() followed by platform_device_register_simple() looks pretty weird, but being a platform device is required for probe deferral. Any better ways to handle this? drivers/cpufreq/Makefile | 1 + drivers/cpufreq/tegra124-cpufreq.c | 221 +++++++++++++++++++++++++++++++++++++ 2 files changed, 222 insertions(+) create mode 100644 drivers/cpufreq/tegra124-cpufreq.c diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile index db6d9a2..3437d24 100644 --- a/drivers/cpufreq/Makefile +++ b/drivers/cpufreq/Makefile @@ -76,6 +76,7 @@ obj-$(CONFIG_ARM_SA1100_CPUFREQ) += sa1100-cpufreq.o obj-$(CONFIG_ARM_SA1110_CPUFREQ) += sa1110-cpufreq.o obj-$(CONFIG_ARM_SPEAR_CPUFREQ) += spear-cpufreq.o obj-$(CONFIG_ARM_TEGRA_CPUFREQ) += tegra-cpufreq.o +obj-$(CONFIG_ARM_TEGRA_CPUFREQ) += tegra124-cpufreq.o obj-$(CONFIG_ARM_VEXPRESS_SPC_CPUFREQ) += vexpress-spc-cpufreq.o ################################################################################## diff --git a/drivers/cpufreq/tegra124-cpufreq.c b/drivers/cpufreq/tegra124-cpufreq.c new file mode 100644 index 0000000..3e29af4 --- /dev/null +++ b/drivers/cpufreq/tegra124-cpufreq.c @@ -0,0 +1,221 @@ +/* + * Tegra 124 cpufreq driver + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * 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. + * + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static struct cpufreq_frequency_table *freq_table; + +static struct device *cpu_dev; +static struct clk *cpu_clk; +static struct clk *pllp_clk; +static struct clk *pllx_clk; +static struct clk *dfll_clk; + +static int tegra124_target(struct cpufreq_policy *policy, unsigned int index) +{ + unsigned long cpu_rate = freq_table[index].frequency; + int ret; + + ret = clk_set_rate(dfll_clk, cpu_rate * 1000); + if (ret) + pr_err("Failed to set cpu frequency to %lu kHz\n", cpu_rate); + + return ret; +} + +static int tegra124_cpu_init(struct cpufreq_policy *policy) +{ + int ret; + + clk_prepare_enable(cpu_clk); + + /* FIXME: what's the actual transition time? */ + ret = cpufreq_generic_init(policy, freq_table, 300 * 1000); + if (ret) { + clk_disable_unprepare(cpu_clk); + return ret; + } + + policy->clk = cpu_clk; + policy->suspend_freq = freq_table[0].frequency; + return 0; +} + +static int tegra124_cpu_exit(struct cpufreq_policy *policy) +{ + clk_disable_unprepare(cpu_clk); + return 0; +} + +static int tegra124_cpu_switch_to_dfll(void) +{ + struct clk *original_cpu_clk_parent; + unsigned long rate; + struct dev_pm_opp *opp; + int ret; + + rate = clk_get_rate(cpu_clk); + opp = dev_pm_opp_find_freq_ceil(cpu_dev, &rate); + if (IS_ERR(opp)) + return PTR_ERR(opp); + + ret = clk_set_rate(dfll_clk, rate); + if (ret) + return ret; + + original_cpu_clk_parent = clk_get_parent(cpu_clk); + clk_set_parent(cpu_clk, pllp_clk); + if (ret) + return ret; + + ret = clk_prepare_enable(dfll_clk); + if (ret) + goto out_switch_to_original_parent; + + clk_set_parent(cpu_clk, dfll_clk); + + return 0; + +out_switch_to_original_parent: + clk_set_parent(cpu_clk, original_cpu_clk_parent); + + return ret; +} + +static struct cpufreq_driver tegra124_cpufreq_driver = { + .verify = cpufreq_generic_frequency_table_verify, + .target_index = tegra124_target, + .get = cpufreq_generic_get, + .init = tegra124_cpu_init, + .exit = tegra124_cpu_exit, + .name = "tegra124", + .attr = cpufreq_generic_attr, +#ifdef CONFIG_PM + .suspend = cpufreq_generic_suspend, +#endif +}; + +static int tegra124_cpufreq_probe(struct platform_device *pdev) +{ + int ret; + + cpu_dev = get_cpu_device(0); + if (!cpu_dev) + return -ENODEV; + + cpu_clk = of_clk_get_by_name(cpu_dev->of_node, "cpu_g"); + if (IS_ERR(cpu_clk)) + return PTR_ERR(cpu_clk); + + dfll_clk = of_clk_get_by_name(cpu_dev->of_node, "dfll"); + if (IS_ERR(dfll_clk)) { + ret = PTR_ERR(dfll_clk); + goto out_put_cpu_clk; + } + + pllx_clk = of_clk_get_by_name(cpu_dev->of_node, "pll_x"); + if (IS_ERR(pllx_clk)) { + ret = PTR_ERR(pllx_clk); + goto out_put_dfll_clk; + } + + pllp_clk = of_clk_get_by_name(cpu_dev->of_node, "pll_p"); + if (IS_ERR(pllp_clk)) { + ret = PTR_ERR(pllp_clk); + goto out_put_pllx_clk; + } + + ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table); + if (ret) + goto out_put_pllp_clk; + + ret = tegra124_cpu_switch_to_dfll(); + if (ret) + goto out_free_table; + + ret = cpufreq_register_driver(&tegra124_cpufreq_driver); + if (ret) { + /* + * The VDD_CPU voltage may have been changed at this point and + * and switching back to PLLX might not be safe. Don't even try. + */ + pr_err("failed to register cpufreq driver: %d\n", ret); + } + + return ret; + +out_free_table: + dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table); +out_put_pllp_clk: + clk_put(pllp_clk); +out_put_pllx_clk: + clk_put(pllx_clk); +out_put_dfll_clk: + clk_put(dfll_clk); +out_put_cpu_clk: + clk_put(cpu_clk); + + return ret; +} + +static struct platform_driver tegra124_cpufreq_platdrv = { + .driver = { + .name = "cpufreq-tegra124", + .owner = THIS_MODULE, + }, + .probe = tegra124_cpufreq_probe, +}; + +static const struct of_device_id soc_of_matches[] = { + { .compatible = "nvidia,tegra124", }, + {} +}; + +static int __init tegra_cpufreq_init(void) +{ + int ret; + struct platform_device *pdev; + + if (!of_find_matching_node(NULL, soc_of_matches)) + return -ENODEV; + + ret = platform_driver_register(&tegra124_cpufreq_platdrv); + if (ret) + return ret; + + pdev = platform_device_register_simple("cpufreq-tegra124", -1, NULL, 0); + if (IS_ERR(pdev)) { + platform_driver_unregister(&tegra124_cpufreq_platdrv); + return PTR_ERR(pdev); + } + + return 0; +} + +MODULE_AUTHOR("Tuomas Tynkkynen "); +MODULE_DESCRIPTION("cpufreq driver for nVIDIA Tegra124"); +MODULE_LICENSE("GPLv2"); +module_init(tegra_cpufreq_init);