From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew-sh.Cheng Subject: [PATCH v2 4/4] devfreq: add mediatek cci devfreq Date: Fri, 29 Mar 2019 14:46:12 +0800 Message-ID: <1553841972-19737-5-git-send-email-andrew-sh.cheng@mediatek.com> References: <1553841972-19737-1-git-send-email-andrew-sh.cheng@mediatek.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1553841972-19737-1-git-send-email-andrew-sh.cheng-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+glpam-linux-mediatek=m.gmane.org-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org To: MyungJoo Ham , Kyungmin Park , Chanwoo Choi , Rob Herring , Mark Rutland , Matthias Brugger , "Rafael J. Wysocki" , Viresh Kumar Cc: devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, "Andrew-sh.Cheng" , srv_heupstream-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org, linux-pm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, fan.chen-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org, linux-mediatek-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: devicetree@vger.kernel.org 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"); + 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"); + 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"); + 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)) { + dev_err(cci_dev, "cannot create cci devfreq device\n", ret); + goto err_put_reg; + } + + return 0; + +err_put_reg: + regulator_put(cci_df->proc_reg); +err_put_clk: + clk_put(cci_df->cci_clk); + + 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, + }, +}; + +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"); -- 1.8.1.1.dirty