From mboxrd@z Thu Jan 1 00:00:00 1970 From: andrew-sh.cheng Subject: Re: [v2,4/4] devfreq: add mediatek cci devfreq Date: Sat, 13 Apr 2019 15:07:24 +0800 Message-ID: <1555139244.22373.2.camel@mtksdaap41> References: <1553841972-19737-5-git-send-email-andrew-sh.cheng@mediatek.com> <20190408172220.GA28972@roeck-us.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190408172220.GA28972@roeck-us.net> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Guenter Roeck Cc: Mark Rutland , devicetree@vger.kernel.org, srv_heupstream@mediatek.com, linux-pm@vger.kernel.org, Viresh Kumar , "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, Chanwoo Choi , Kyungmin Park , Rob Herring , linux-mediatek@lists.infradead.org, MyungJoo Ham , Matthias Brugger , fan.chen@mediatek.com, linux-arm-kernel@lists.infradead.org List-Id: devicetree@vger.kernel.org On Mon, 2019-04-08 at 10:22 -0700, Guenter Roeck wrote: > On Fri, Mar 29, 2019 at 02:46:12PM +0800, Andrew-sh Cheng wrote: > > This adds a devfreq driver for the Cache Coherent Interconnect (CCI) > > of the Mediatek MT8183. > > > > On the MT8183 the CCI is supplied by the same regulator as the LITTLE > > cores. The driver is notified when the regulator voltage changes > > (driven by cpufreq) and adjusts the CCI frequency to the maximum > > possible value. > > > > Signed-off-by: Andrew-sh.Cheng > > --- > > drivers/devfreq/Kconfig | 10 ++ > > drivers/devfreq/Makefile | 1 + > > drivers/devfreq/mt8183-cci-devfreq.c | 235 +++++++++++++++++++++++++++++++++++ > > 3 files changed, 246 insertions(+) > > create mode 100644 drivers/devfreq/mt8183-cci-devfreq.c > > > > diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig > > index 6a172d3..da2f8ec 100644 > > --- a/drivers/devfreq/Kconfig > > +++ b/drivers/devfreq/Kconfig > > @@ -91,6 +91,16 @@ config ARM_EXYNOS_BUS_DEVFREQ > > and adjusts the operating frequencies and voltages with OPP support. > > This does not yet operate with optimal voltages. > > > > +config ARM_MT8183_CCI_DEVFREQ > > + tristate "MT8183 CCI DEVFREQ Driver" > > + depends on ARM_MEDIATEK_CPUFREQ > > + help > > + This adds a devfreq driver for Cache Coherent Interconnect > > + of Mediatek MT8183, which is shared the same regulator > > + with cpu cluster. > > + It can track buck voltage and update a proper cci frequency. > > + Use notification to get regulator status. > > + > > config ARM_TEGRA_DEVFREQ > > tristate "Tegra DEVFREQ Driver" > > depends on ARCH_TEGRA_124_SOC > > diff --git a/drivers/devfreq/Makefile b/drivers/devfreq/Makefile > > index 32b8d4d..817dde7 100644 > > --- a/drivers/devfreq/Makefile > > +++ b/drivers/devfreq/Makefile > > @@ -9,6 +9,7 @@ obj-$(CONFIG_DEVFREQ_GOV_PASSIVE) += governor_passive.o > > > > # DEVFREQ Drivers > > obj-$(CONFIG_ARM_EXYNOS_BUS_DEVFREQ) += exynos-bus.o > > +obj-$(CONFIG_ARM_MT8183_CCI_DEVFREQ) += mt8183-cci-devfreq.o > > obj-$(CONFIG_ARM_RK3399_DMC_DEVFREQ) += rk3399_dmc.o > > obj-$(CONFIG_ARM_TEGRA_DEVFREQ) += tegra-devfreq.o > > > > diff --git a/drivers/devfreq/mt8183-cci-devfreq.c b/drivers/devfreq/mt8183-cci-devfreq.c > > new file mode 100644 > > index 0000000..af82d2e > > --- /dev/null > > +++ b/drivers/devfreq/mt8183-cci-devfreq.c > > @@ -0,0 +1,235 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +/* > > + * Copyright (c) 2019 MediaTek Inc. > > + */ > > + > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > + > > +#include "governor.h" > > + > > +struct cci_devfreq { > > + struct devfreq *devfreq; > > + struct regulator *proc_reg; > > + unsigned long proc_reg_uV; > > + struct clk *cci_clk; > > + struct notifier_block nb; > > +}; > > + > > +static int cci_devfreq_regulator_notifier(struct notifier_block *nb, > > + unsigned long val, void *data) > > +{ > > + struct cci_devfreq *cci_df = > > + container_of(nb, struct cci_devfreq, nb); > > + > > + /* deal with reduce frequency */ > > + if (val & REGULATOR_EVENT_PRE_VOLTAGE_CHANGE) { > > + struct pre_voltage_change_data *pvc_data = data; > > + > > + if (pvc_data->min_uV < pvc_data->old_uV) { > > + cci_df->proc_reg_uV = > > + (unsigned long)(pvc_data->min_uV); > > + mutex_lock(&cci_df->devfreq->lock); > > + update_devfreq(cci_df->devfreq); > > + mutex_unlock(&cci_df->devfreq->lock); > > + } > > + } > > + > > + if ((val & REGULATOR_EVENT_ABORT_VOLTAGE_CHANGE) && > > + ((unsigned long)data > cci_df->proc_reg_uV)) { > > + cci_df->proc_reg_uV = (unsigned long)data; > > + mutex_lock(&cci_df->devfreq->lock); > > + update_devfreq(cci_df->devfreq); > > + mutex_unlock(&cci_df->devfreq->lock); > > + } > > + > > + /* deal with increase frequency */ > > + if ((val & REGULATOR_EVENT_VOLTAGE_CHANGE) && > > + (cci_df->proc_reg_uV < (unsigned long)data)) { > > + cci_df->proc_reg_uV = (unsigned long)data; > > + mutex_lock(&cci_df->devfreq->lock); > > + update_devfreq(cci_df->devfreq); > > + mutex_unlock(&cci_df->devfreq->lock); > > + } > > + > > + return 0; > > +} > > + > > +static int mtk_cci_governor_get_target(struct devfreq *devfreq, > > + unsigned long *freq) > > +{ > > + struct cci_devfreq *cci_df; > > + struct dev_pm_opp *opp; > > + > > + cci_df = dev_get_drvdata(devfreq->dev.parent); > > + > > + /* find available frequency */ > > + opp = dev_pm_opp_find_max_freq_by_volt(devfreq->dev.parent, > > + cci_df->proc_reg_uV); > > + *freq = dev_pm_opp_get_freq(opp); > > + > > + return 0; > > +} > > + > > +static int mtk_cci_governor_event_handler(struct devfreq *devfreq, > > + unsigned int event, void *data) > > +{ > > + struct cci_devfreq *cci_df; > > + struct notifier_block *nb; > > + > > + cci_df = dev_get_drvdata(devfreq->dev.parent); > > + nb = &cci_df->nb; > > + > > + switch (event) { > > + case DEVFREQ_GOV_START: > > + case DEVFREQ_GOV_RESUME: > > + nb->notifier_call = cci_devfreq_regulator_notifier; > > + regulator_register_notifier(cci_df->proc_reg, > > + nb); > > + break; > > + > > + case DEVFREQ_GOV_STOP: > > + case DEVFREQ_GOV_SUSPEND: > > + regulator_unregister_notifier(cci_df->proc_reg, > > + nb); > > + > > + break; > > + > > + default: > > + break; > > + } > > + > > + return 0; > > +} > > + > > +static struct devfreq_governor mtk_cci_devfreq_governor = { > > + .name = "mtk_cci_vmon", > > + .get_target_freq = mtk_cci_governor_get_target, > > + .event_handler = mtk_cci_governor_event_handler, > > +}; > > + > > +static int mtk_cci_devfreq_target(struct device *dev, unsigned long *freq, > > + u32 flags) > > +{ > > + struct cci_devfreq *cci_df = dev_get_drvdata(dev); > > + > > + if (!cci_df) > > + return -EINVAL; > > + > > + clk_set_rate(cci_df->cci_clk, *freq); > > + > > + return 0; > > +} > > + > > +static struct devfreq_dev_profile cci_devfreq_profile = { > > + .target = mtk_cci_devfreq_target, > > +}; > > + > > +static int mtk_cci_devfreq_probe(struct platform_device *pdev) > > +{ > > + struct device *cci_dev = &pdev->dev; > > + struct cci_devfreq *cci_df; > > + int ret; > > + > > + cci_df = devm_kzalloc(cci_dev, sizeof(*cci_df), GFP_KERNEL); > > + if (!cci_df) > > + return -ENOMEM; > > + > > + cci_df->cci_clk = clk_get(cci_dev, "cci_clock"); > > Should use devm_clk_get(). I will change it on next patch. > > > + ret = PTR_ERR_OR_ZERO(cci_df->cci_clk); > > + if (ret) { > > + if (ret != -EPROBE_DEFER) > > + dev_err(cci_dev, "failed to get clock for CCI: %d\n", > > + ret); > > + > > + return ret; > > + } > > + > > + cci_df->proc_reg = regulator_get_optional(cci_dev, "proc"); > > Should use devm_regulator_get_optional(). I will change it on next patch. > > > + ret = PTR_ERR_OR_ZERO(cci_df->proc_reg); > > + if (ret) { > > + if (ret != -EPROBE_DEFER) > > + dev_err(cci_dev, "failed to get regulator for CCI: %d\n", > > + ret); > > + > > + goto err_put_clk; > > + } > > + > > + ret = dev_pm_opp_of_add_table(&pdev->dev); > > + if (ret) { > > + dev_err(cci_dev, "Fail to init CCI OPP table\n"); > > No error code display here ? Not that it really matters, but it is > inconsistent with the other error messages. I will add it on next patch. > > > + goto err_put_reg; > > + } > > + > > + platform_set_drvdata(pdev, cci_df); > > + > > + cci_df->devfreq = devm_devfreq_add_device(cci_dev, > > + &cci_devfreq_profile, > > + "mtk_cci_vmon", > > + NULL); > > + if (IS_ERR(cci_df->devfreq)) { > > ret = PTR_ERR(cci_df->devfreq); > > > + dev_err(cci_dev, "cannot create cci devfreq device\n", ret); > > dev_err(cci_dev, "cannot create cci devfreq device: %d\n", ret); > > Something like > dev_pm_opp_of_remove_table(...); > seems to be missing here. I will fix this, and add dev_pm_opp_of_remove_table(...) when error occur. > > > + goto err_put_reg; > > + } > > + > > + return 0; > > + > > +err_put_reg: > > + regulator_put(cci_df->proc_reg); > > +err_put_clk: > > + clk_put(cci_df->cci_clk); > > Can be dropped when using devm_ functions above. I will remove these code. > > > + > > + return ret; > > +} > > + > > +static const struct of_device_id mediatek_cci_devfreq_of_match[] = { > > + { .compatible = "mediatek,mt8183-cci" }, > > + { }, > > +}; > > +MODULE_DEVICE_TABLE(of, mediatek_cci_devfreq_of_match); > > + > > +static struct platform_driver cci_devfreq_driver = { > > + .probe = mtk_cci_devfreq_probe, > > + .driver = { > > + .name = "mediatek-cci-devfreq", > > + .of_match_table = mediatek_cci_devfreq_of_match, > > If the driver depends on OF, that should be stated in the Kconfig file. > Otherwise, of_match_ptr() should be used, and mediatek_cci_devfreq_of_match > should be tagged with __maybe_unused (or made conditional with #ifdef). I will fix this on next patch. > > > + }, > > +}; > > + > > +static int __init mtk_cci_devfreq_init(void) > > +{ > > + int ret; > > + > > + ret = devfreq_add_governor(&mtk_cci_devfreq_governor); > > + if (ret) { > > + pr_err("%s: failed to add governor: %d\n", __func__, ret); > > + return ret; > > + } > > + > > + ret = platform_driver_register(&cci_devfreq_driver); > > + if (ret) > > + devfreq_remove_governor(&mtk_cci_devfreq_governor); > > + > > + return ret; > > +} > > +module_init(mtk_cci_devfreq_init) > > + > > +static void __exit mtk_cci_devfreq_exit(void) > > +{ > > + int ret; > > + > > + ret = devfreq_remove_governor(&mtk_cci_devfreq_governor); > > + if (ret) > > + pr_err("%s: failed to remove governor: %d\n", __func__, ret); > > + > > + platform_driver_unregister(&cci_devfreq_driver); > > +} > > +module_exit(mtk_cci_devfreq_exit) > > + > > +MODULE_DESCRIPTION("Mediatek CCI devfreq driver"); > > +MODULE_AUTHOR("Andrew-sh.Cheng "); > > +MODULE_LICENSE("GPL v2"); > > _______________________________________________ > Linux-mediatek mailing list > Linux-mediatek@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-mediatek