diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig index f56132b0ae64..2538255ac2c1 100644 --- a/drivers/devfreq/Kconfig +++ b/drivers/devfreq/Kconfig @@ -111,6 +111,16 @@ config ARM_IMX8M_DDRC_DEVFREQ This adds the DEVFREQ driver for the i.MX8M DDR Controller. It allows adjusting DRAM frequency. +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 "NVIDIA Tegra30/114/124/210 DEVFREQ Driver" depends on ARCH_TEGRA_3x_SOC || ARCH_TEGRA_114_SOC || \ diff --git a/drivers/devfreq/Makefile b/drivers/devfreq/Makefile index a16333ea7034..991ef7740759 100644 --- a/drivers/devfreq/Makefile +++ b/drivers/devfreq/Makefile @@ -11,6 +11,7 @@ obj-$(CONFIG_DEVFREQ_GOV_PASSIVE) += governor_passive.o obj-$(CONFIG_ARM_EXYNOS_BUS_DEVFREQ) += exynos-bus.o obj-$(CONFIG_ARM_IMX_BUS_DEVFREQ) += imx-bus.o obj-$(CONFIG_ARM_IMX8M_DDRC_DEVFREQ) += imx8m-ddrc.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) += tegra30-devfreq.o diff --git a/drivers/devfreq/mt8183-cci-devfreq.c b/drivers/devfreq/mt8183-cci-devfreq.c new file mode 100644 index 000000000000..018543db7bae --- /dev/null +++ b/drivers/devfreq/mt8183-cci-devfreq.c @@ -0,0 +1,198 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2021 MediaTek Inc. + + * Author: Andrew-sh.Cheng + */ + +#include +#include +#include +#include +#include +#include +#include + +#define MAX_VOLT_LIMIT (1150000) + +struct cci_devfreq { + struct devfreq *devfreq; + struct regulator *cpu_reg; + struct clk *cci_clk; + int old_vproc; + unsigned long old_freq; +}; + +static int mtk_cci_set_voltage(struct cci_devfreq *cci_df, int vproc) +{ + int ret; + + ret = regulator_set_voltage(cci_df->cpu_reg, vproc, + MAX_VOLT_LIMIT); + if (!ret) + cci_df->old_vproc = vproc; + return ret; +} + +static int mtk_cci_devfreq_target(struct device *dev, unsigned long *freq, + u32 flags) +{ + int ret; + struct cci_devfreq *cci_df = dev_get_drvdata(dev); + struct dev_pm_opp *opp; + unsigned long opp_rate, opp_voltage, old_voltage; + + if (!cci_df) + return -EINVAL; + + if (cci_df->old_freq == *freq) + return 0; + + opp_rate = *freq; + opp = devfreq_recommended_opp(dev, &opp_rate, 1); + opp_voltage = dev_pm_opp_get_voltage(opp); + dev_pm_opp_put(opp); + + old_voltage = cci_df->old_vproc; + if (old_voltage == 0) + old_voltage = regulator_get_voltage(cci_df->cpu_reg); + + // scale up: set voltage first then freq + if (opp_voltage > old_voltage) { + ret = mtk_cci_set_voltage(cci_df, opp_voltage); + if (ret) { + pr_err("cci: failed to scale up voltage\n"); + return ret; + } + } + + ret = clk_set_rate(cci_df->cci_clk, *freq); + if (ret) { + pr_err("%s: failed cci to set rate: %d\n", __func__, + ret); + mtk_cci_set_voltage(cci_df, old_voltage); + return ret; + } + + // scale down: set freq first then voltage + if (opp_voltage < old_voltage) { + ret = mtk_cci_set_voltage(cci_df, opp_voltage); + if (ret) { + pr_err("cci: failed to scale down voltage\n"); + clk_set_rate(cci_df->cci_clk, cci_df->old_freq); + return ret; + } + } + + cci_df->old_freq = *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; + struct devfreq_passive_data *passive_data; + int ret; + + cci_df = devm_kzalloc(cci_dev, sizeof(*cci_df), GFP_KERNEL); + if (!cci_df) + return -ENOMEM; + + cci_df->cci_clk = devm_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->cpu_reg = devm_regulator_get_optional(cci_dev, "proc"); + ret = PTR_ERR_OR_ZERO(cci_df->cpu_reg); + if (ret) { + if (ret != -EPROBE_DEFER) + dev_err(cci_dev, "failed to get regulator for CCI: %d\n", + ret); + return ret; + } + ret = regulator_enable(cci_df->cpu_reg); + if (ret) { + dev_err(cci_dev, "enable buck for cci fail\n"); + return ret; + } + + ret = dev_pm_opp_of_add_table(cci_dev); + if (ret) { + dev_err(cci_dev, "Fail to get OPP table for CCI: %d\n", ret); + return ret; + } + + platform_set_drvdata(pdev, cci_df); + + passive_data = devm_kzalloc(cci_dev, sizeof(*passive_data), GFP_KERNEL); + if (!passive_data) { + ret = -ENOMEM; + goto err_opp; + } + + passive_data->parent_type = CPUFREQ_PARENT_DEV; + + cci_df->devfreq = devm_devfreq_add_device(cci_dev, + &cci_devfreq_profile, + DEVFREQ_GOV_PASSIVE, + passive_data); + if (IS_ERR(cci_df->devfreq)) { + ret = PTR_ERR(cci_df->devfreq); + dev_err(cci_dev, "cannot create cci devfreq device:%d\n", ret); + goto err_opp; + } + + return 0; + +err_opp: + dev_pm_opp_of_remove_table(cci_dev); + return ret; +} + +static int mtk_cci_devfreq_remove(struct platform_device *pdev) +{ + struct device *cci_dev = &pdev->dev; + struct cci_devfreq *cci_df; + struct notifier_block *opp_nb; + + cci_df = platform_get_drvdata(pdev); + opp_nb = &cci_df->opp_nb; + + dev_pm_opp_unregister_notifier(cci_dev, opp_nb); + dev_pm_opp_of_remove_table(cci_dev); + regulator_disable(cci_df->cpu_reg); + + return 0; +} + +static const __maybe_unused struct of_device_id + mediatek_cci_of_match[] = { + { .compatible = "mediatek,mt8183-cci" }, + { }, +}; +MODULE_DEVICE_TABLE(of, mediatek_cci_of_match); + +static struct platform_driver cci_devfreq_driver = { + .probe = mtk_cci_devfreq_probe, + .remove = mtk_cci_devfreq_remove, + .driver = { + .name = "mediatek-cci-devfreq", + .of_match_table = of_match_ptr(mediatek_cci_of_match), + }, +}; + +module_platform_driver(cci_devfreq_driver); + +MODULE_DESCRIPTION("Mediatek CCI devfreq driver"); +MODULE_AUTHOR("Andrew-sh.Cheng "); +MODULE_LICENSE("GPL v2");