From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5600AC32788 for ; Thu, 11 Oct 2018 11:19:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D75A42087D for ; Thu, 11 Oct 2018 11:19:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="DBX3aWvb"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="kafBnz2v" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D75A42087D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728381AbeJKSqW (ORCPT ); Thu, 11 Oct 2018 14:46:22 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:38514 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726135AbeJKSqW (ORCPT ); Thu, 11 Oct 2018 14:46:22 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id DEB8960C7D; Thu, 11 Oct 2018 11:19:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1539256774; bh=VblFLL0PU8ONHPrlwgpjsaOc/BeWq9SjqSCOpHgAn20=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=DBX3aWvbapVwRNeia/s9H8FIAihJNmuPTHIU4HiSIZjQHVcQHD+hiHLpJXvgI7yZE JvECSLO730Qe83dnLlDAhOvcC/axFSVmM3xCBgCJbaC1tupjqbTSkVAy1+HlE0PfnX Zljo73UpAJFzycL3PNfZTQnprDlKIAFfpUxNA8yY= Received: from [10.79.167.189] (blr-bdr-fw-01_globalnat_allzones-outside.qualcomm.com [103.229.18.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: tdas@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id 169E0600C1; Thu, 11 Oct 2018 11:19:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1539256773; bh=VblFLL0PU8ONHPrlwgpjsaOc/BeWq9SjqSCOpHgAn20=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=kafBnz2vRFhO5MpCu1prLwrCtWvai25mhi0Ftvv5RfIvIKm9l9GEKCYlcxPtoQQ2A tLZIa8U0Mlanb4U3FB8lVz0jccTljaJDMmcqyPu8LW9LdKK+xbbPgsUOHGEw0B712k Pz6NI2Sgr0DdvW7S7cXXQDIKVI/IXhNoPqvvGj88= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 169E0600C1 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=tdas@codeaurora.org Subject: Re: [PATCH v8 2/2] cpufreq: qcom-hw: Add support for QCOM cpufreq HW driver To: Viresh Kumar Cc: "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, Stephen Boyd , Rajendra Nayak , devicetree@vger.kernel.org, robh@kernel.org, skannan@codeaurora.org, linux-arm-msm@vger.kernel.org, amit.kucheria@linaro.org, evgreen@google.com References: <1537698793-15285-1-git-send-email-tdas@codeaurora.org> <1537698793-15285-3-git-send-email-tdas@codeaurora.org> <20181005105506.neri7niyelz2ahc5@vireshk-i7> From: Taniya Das Message-ID: <14e5ca05-0388-2414-0a56-d73fc23ab4cc@codeaurora.org> Date: Thu, 11 Oct 2018 16:49:24 +0530 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20181005105506.neri7niyelz2ahc5@vireshk-i7> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Viresh, Thanks for your review comments. On 10/5/2018 4:25 PM, Viresh Kumar wrote: > On 23-09-18, 16:03, Taniya Das wrote: >> The CPUfreq HW present in some QCOM chipsets offloads the steps necessary >> for changing the frequency of CPUs. The driver implements the cpufreq >> driver interface for this hardware engine. >> >> Signed-off-by: Saravana Kannan >> Signed-off-by: Taniya Das >> --- >> drivers/cpufreq/Kconfig.arm | 11 ++ >> drivers/cpufreq/Makefile | 1 + >> drivers/cpufreq/qcom-cpufreq-hw.c | 354 ++++++++++++++++++++++++++++++++++++++ >> 3 files changed, 366 insertions(+) >> create mode 100644 drivers/cpufreq/qcom-cpufreq-hw.c >> >> diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm >> index 0cd8eb7..93a9d72 100644 >> --- a/drivers/cpufreq/Kconfig.arm >> +++ b/drivers/cpufreq/Kconfig.arm >> @@ -298,3 +298,14 @@ config ARM_PXA2xx_CPUFREQ >> This add the CPUFreq driver support for Intel PXA2xx SOCs. >> >> If in doubt, say N. >> + >> +config ARM_QCOM_CPUFREQ_HW >> + bool "QCOM CPUFreq HW driver" >> + depends on ARCH_QCOM >> + help >> + Support for the CPUFreq HW driver. >> + Some QCOM chipsets have a HW engine to offload the steps >> + necessary for changing the frequency of the CPUs. Firmware loaded >> + in this engine exposes a programming interface to the OS. >> + The driver implements the cpufreq interface for this HW engine. >> + Say Y if you want to support CPUFreq HW. >> diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile >> index c1ffeab..ca48a1d 100644 >> --- a/drivers/cpufreq/Makefile >> +++ b/drivers/cpufreq/Makefile >> @@ -85,6 +85,7 @@ 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_QCOM_CPUFREQ_HW) += qcom-cpufreq-hw.o >> >> >> ################################################################################## >> diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c >> new file mode 100644 >> index 0000000..43107ab >> --- /dev/null >> +++ b/drivers/cpufreq/qcom-cpufreq-hw.c >> @@ -0,0 +1,354 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +/* >> + * Copyright (c) 2018, The Linux Foundation. All rights reserved. >> + */ >> + >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> + >> +#define LUT_MAX_ENTRIES 40U >> +#define CORE_COUNT_VAL(val) (((val) & (GENMASK(18, 16))) >> 16) >> +#define LUT_ROW_SIZE 32 >> +#define CLK_HW_DIV 2 >> + >> +enum { >> + REG_ENABLE, >> + REG_LUT_TABLE, >> + REG_PERF_STATE, >> + >> + REG_ARRAY_SIZE, >> +}; >> + >> +struct cpufreq_qcom { >> + struct cpufreq_frequency_table *table; >> + void __iomem *reg_bases[REG_ARRAY_SIZE]; >> + cpumask_t related_cpus; >> + unsigned int max_cores; >> + unsigned long xo_rate; >> + unsigned long cpu_hw_rate; >> +}; >> + >> +static const u16 cpufreq_qcom_std_offsets[REG_ARRAY_SIZE] = { >> + [REG_ENABLE] = 0x0, >> + [REG_LUT_TABLE] = 0x110, >> + [REG_PERF_STATE] = 0x920, >> +}; >> + >> +static struct cpufreq_qcom *qcom_freq_domain_map[NR_CPUS]; >> + >> +static int >> +qcom_cpufreq_hw_target_index(struct cpufreq_policy *policy, >> + unsigned int index) >> +{ >> + struct cpufreq_qcom *c = policy->driver_data; >> + >> + writel_relaxed(index, c->reg_bases[REG_PERF_STATE]); >> + >> + return 0; >> +} >> + >> +static unsigned int qcom_cpufreq_hw_get(unsigned int cpu) >> +{ >> + struct cpufreq_qcom *c; >> + struct cpufreq_policy *policy; >> + unsigned int index; >> + >> + policy = cpufreq_cpu_get_raw(cpu); >> + if (!policy) >> + return 0; >> + >> + c = policy->driver_data; >> + >> + index = readl_relaxed(c->reg_bases[REG_PERF_STATE]); >> + index = min(index, LUT_MAX_ENTRIES - 1); >> + >> + return policy->freq_table[index].frequency; >> +} >> + >> +static unsigned int >> +qcom_cpufreq_hw_fast_switch(struct cpufreq_policy *policy, >> + unsigned int target_freq) >> +{ >> + struct cpufreq_qcom *c = policy->driver_data; >> + int index; >> + >> + index = policy->cached_resolved_idx; >> + if (index < 0) >> + return 0; >> + >> + writel_relaxed(index, c->reg_bases[REG_PERF_STATE]); >> + >> + return policy->freq_table[index].frequency; >> +} >> + >> +static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy) >> +{ >> + struct cpufreq_qcom *c; >> + >> + c = qcom_freq_domain_map[policy->cpu]; >> + if (!c) { >> + pr_err("No scaling support for CPU%d\n", policy->cpu); >> + return -ENODEV; >> + } >> + >> + cpumask_copy(policy->cpus, &c->related_cpus); >> + >> + policy->fast_switch_possible = true; >> + policy->freq_table = c->table; >> + policy->driver_data = c; >> + >> + return 0; >> +} >> + >> +static struct freq_attr *qcom_cpufreq_hw_attr[] = { >> + &cpufreq_freq_attr_scaling_available_freqs, >> + &cpufreq_freq_attr_scaling_boost_freqs, >> + NULL >> +}; >> + >> +static struct cpufreq_driver cpufreq_qcom_hw_driver = { >> + .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK | >> + CPUFREQ_HAVE_GOVERNOR_PER_POLICY, >> + .verify = cpufreq_generic_frequency_table_verify, >> + .target_index = qcom_cpufreq_hw_target_index, >> + .get = qcom_cpufreq_hw_get, >> + .init = qcom_cpufreq_hw_cpu_init, >> + .fast_switch = qcom_cpufreq_hw_fast_switch, >> + .name = "qcom-cpufreq-hw", >> + .attr = qcom_cpufreq_hw_attr, >> + .boost_enabled = true, >> +}; >> + >> +static int qcom_cpufreq_hw_read_lut(struct platform_device *pdev, >> + struct cpufreq_qcom *c) >> +{ >> + struct device *dev = &pdev->dev; >> + void __iomem *base; >> + u32 data, src, lval, i, core_count, prev_cc, prev_freq, cur_freq; >> + >> + c->table = devm_kcalloc(dev, LUT_MAX_ENTRIES + 1, >> + sizeof(*c->table), GFP_KERNEL); >> + if (!c->table) >> + return -ENOMEM; >> + >> + base = c->reg_bases[REG_LUT_TABLE]; >> + >> + for (i = 0; i < LUT_MAX_ENTRIES; i++) { >> + data = readl_relaxed(base + i * LUT_ROW_SIZE); >> + src = (data & GENMASK(31, 30)) >> 30; >> + lval = data & GENMASK(7, 0); >> + core_count = CORE_COUNT_VAL(data); >> + >> + if (src) >> + c->table[i].frequency = c->xo_rate * lval / 1000; >> + else >> + c->table[i].frequency = c->cpu_hw_rate / 1000; >> + >> + cur_freq = c->table[i].frequency; >> + >> + dev_dbg(dev, "index=%d freq=%d, core_count %d\n", >> + i, c->table[i].frequency, core_count); >> + >> + if (core_count != c->max_cores) >> + cur_freq = CPUFREQ_ENTRY_INVALID; >> + >> + /* >> + * Two of the same frequencies with the same core counts means >> + * end of table. >> + */ >> + if (i > 0 && c->table[i - 1].frequency == >> + c->table[i].frequency && prev_cc == core_count) { >> + struct cpufreq_frequency_table *prev = &c->table[i - 1]; >> + >> + if (prev_freq == CPUFREQ_ENTRY_INVALID) >> + prev->flags = CPUFREQ_BOOST_FREQ; >> + break; >> + } >> + prev_cc = core_count; >> + prev_freq = cur_freq; >> + } > > The logic here always surprises me, why does the firmware keeps the > table this way instead of simplifying it ? > Unfortunately that is the only way to identify. >> + >> + c->table[i].frequency = CPUFREQ_TABLE_END; >> + >> + return 0; >> +} >> + >> +static int qcom_get_related_cpus(int index, struct cpumask *m) >> +{ >> + struct device_node *cpu_np; >> + struct of_phandle_args args; >> + int cpu, ret; >> + >> + for_each_possible_cpu(cpu) { >> + cpu_np = of_cpu_device_node_get(cpu); >> + if (!cpu_np) >> + continue; >> + of_node_put(cpu_np); > > Heh, you can't do that here :) > Yes, I would take care to put it in the right place. >> + >> + ret = of_parse_phandle_with_args(cpu_np, "qcom,freq-domain", > > As this code still needs to use the same pointer. It is possible that > the memory associated with cpu_np gets freed as soon as you call > of_node_put() on that. You should call of_node_put() anytime after > this routine is called. > >> + "#freq-domain-cells", 0, &args); >> + if (ret < 0) >> + continue; >> + >> + if (index == args.args[0]) >> + cpumask_set_cpu(cpu, m); >> + } >> + >> + return 0; >> +} >> + >> +static int qcom_cpu_resources_init(struct platform_device *pdev, >> + unsigned int cpu, int index, >> + unsigned long xo_rate, >> + unsigned long cpu_hw_rate) >> +{ >> + struct cpufreq_qcom *c; >> + struct resource *res; >> + struct device *dev = &pdev->dev; >> + const u16 *offsets; >> + int ret, i, cpu_r; >> + void __iomem *base; >> + >> + if (qcom_freq_domain_map[cpu]) >> + return 0; >> + >> + c = devm_kzalloc(dev, sizeof(*c), GFP_KERNEL); >> + if (!c) >> + return -ENOMEM; >> + >> + offsets = of_device_get_match_data(&pdev->dev); >> + if (!offsets) >> + return -EINVAL; >> + >> + res = platform_get_resource(pdev, IORESOURCE_MEM, index); >> + base = devm_ioremap_resource(dev, res); >> + if (IS_ERR(base)) >> + return PTR_ERR(base); >> + >> + for (i = REG_ENABLE; i < REG_ARRAY_SIZE; i++) >> + c->reg_bases[i] = base + offsets[i]; >> + >> + /* HW should be in enabled state to proceed */ >> + if (!(readl_relaxed(c->reg_bases[REG_ENABLE]) & 0x1)) { >> + dev_err(dev, "Domain-%d cpufreq hardware not enabled\n", index); >> + return -ENODEV; >> + } >> + >> + ret = qcom_get_related_cpus(index, &c->related_cpus); >> + if (ret) { >> + dev_err(dev, "Domain-%d failed to get related CPUs\n", index); >> + return ret; >> + } >> + >> + c->max_cores = cpumask_weight(&c->related_cpus); >> + if (!c->max_cores) >> + return -ENOENT; >> + >> + c->xo_rate = xo_rate; >> + c->cpu_hw_rate = cpu_hw_rate; >> + >> + ret = qcom_cpufreq_hw_read_lut(pdev, c); >> + if (ret) { >> + dev_err(dev, "Domain-%d failed to read LUT\n", index); >> + return ret; >> + } >> + >> + for_each_cpu(cpu_r, &c->related_cpus) >> + qcom_freq_domain_map[cpu_r] = c; >> + >> + return 0; >> +} >> + >> +static int qcom_resources_init(struct platform_device *pdev) >> +{ >> + struct device_node *cpu_np; >> + struct of_phandle_args args; >> + struct clk *clk; >> + unsigned int cpu; >> + unsigned long xo_rate, cpu_hw_rate; >> + int ret; >> + >> + clk = devm_clk_get(&pdev->dev, "xo"); >> + if (IS_ERR(clk)) >> + return PTR_ERR(clk); >> + >> + xo_rate = clk_get_rate(clk); >> + >> + devm_clk_put(&pdev->dev, clk); > > Why use devm_ variants if you want to put the clock anyway ? > Would move to non devm_ variants. >> + clk = devm_clk_get(&pdev->dev, "cpu_clk"); >> + if (IS_ERR(clk)) >> + return PTR_ERR(clk); >> + >> + cpu_hw_rate = clk_get_rate(clk) / CLK_HW_DIV; >> + >> + devm_clk_put(&pdev->dev, clk); > > same here. > >> + >> + for_each_possible_cpu(cpu) { >> + cpu_np = of_cpu_device_node_get(cpu); > > Where is the of_node_put() corresponding to this ? > >> + if (!cpu_np) { >> + dev_dbg(&pdev->dev, "Failed to get cpu %d device\n", >> + cpu); >> + continue; >> + } >> + >> + ret = of_parse_phandle_with_args(cpu_np, "qcom,freq-domain", >> + "#freq-domain-cells", 0, &args); >> + if (ret < 0) >> + return ret; >> + >> + ret = qcom_cpu_resources_init(pdev, cpu, args.args[0], >> + xo_rate, cpu_hw_rate); >> + if (ret) >> + return ret; >> + } >> + >> + return 0; >> +} >> + >> +static int qcom_cpufreq_hw_driver_probe(struct platform_device *pdev) >> +{ >> + int rc; >> + >> + /* Get the bases of cpufreq for domains */ >> + rc = qcom_resources_init(pdev); >> + if (rc) { >> + dev_err(&pdev->dev, "CPUFreq resource init failed\n"); >> + return rc; >> + } >> + >> + rc = cpufreq_register_driver(&cpufreq_qcom_hw_driver); >> + if (rc) { >> + dev_err(&pdev->dev, "CPUFreq HW driver failed to register\n"); >> + return rc; >> + } >> + >> + dev_dbg(&pdev->dev, "QCOM CPUFreq HW driver initialized\n"); >> + >> + return 0; >> +} >> + >> +static const struct of_device_id qcom_cpufreq_hw_match[] = { >> + { .compatible = "qcom,cpufreq-hw", .data = &cpufreq_qcom_std_offsets }, >> + {} >> +}; >> + >> +static struct platform_driver qcom_cpufreq_hw_driver = { >> + .probe = qcom_cpufreq_hw_driver_probe, >> + .driver = { >> + .name = "qcom-cpufreq-hw", >> + .of_match_table = qcom_cpufreq_hw_match, >> + }, >> +}; >> + >> +static int __init qcom_cpufreq_hw_init(void) >> +{ >> + return platform_driver_register(&qcom_cpufreq_hw_driver); >> +} >> +subsys_initcall(qcom_cpufreq_hw_init); >> + >> +MODULE_DESCRIPTION("QCOM firmware-based CPU Frequency driver"); >> -- >> Qualcomm INDIA, on behalf of Qualcomm Innovation Center, Inc.is a member >> of the Code Aurora Forum, hosted by the Linux Foundation. > -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation. --