[RFCv2 6/8] devfreq: Add imx-devfreq driver
From: Leonard Crestez <hidden>
Date: 2019-06-28 07:40:10
Also in:
linux-clk, linux-pm
Subsystem:
device frequency (devfreq), the rest · Maintainers:
MyungJoo Ham, Kyungmin Park, Chanwoo Choi, Linus Torvalds
Add initial support for frequency switches on pieces of the imx interconnect fabric. Uses clk_set_min_rate so that other subsytems can also impose minimum rate requests. Signed-off-by: Leonard Crestez <redacted> --- drivers/devfreq/Kconfig | 10 +++ drivers/devfreq/Makefile | 1 + drivers/devfreq/imx-devfreq.c | 142 ++++++++++++++++++++++++++++++++++ 3 files changed, 153 insertions(+) create mode 100644 drivers/devfreq/imx-devfreq.c
diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig
index f3b242987fd9..3a7c6265ca2f 100644
--- a/drivers/devfreq/Kconfig
+++ b/drivers/devfreq/Kconfig@@ -90,10 +90,20 @@ config ARM_EXYNOS_BUS_DEVFREQ Each memory bus group could contain many memoby bus block. It reads PPMU counters of memory controllers by using DEVFREQ-event device and adjusts the operating frequencies and voltages with OPP support. This does not yet operate with optimal voltages. +config ARM_IMX_DEVFREQ + tristate "i.MX DEVFREQ Driver" + depends on ARCH_MXC + select DEVFREQ_GOV_USERSPACE + select PM_OPP + help + This adds the DEVFREQ driver for the Tegra family of SoCs. + It reads ACTMON counters of memory controllers and adjusts the + operating frequencies and voltages with OPP support. + config ARM_TEGRA_DEVFREQ tristate "NVIDIA Tegra30/114/124/210 DEVFREQ Driver" depends on ARCH_TEGRA_3x_SOC || ARCH_TEGRA_114_SOC || \ ARCH_TEGRA_132_SOC || ARCH_TEGRA_124_SOC || \ ARCH_TEGRA_210_SOC || \
diff --git a/drivers/devfreq/Makefile b/drivers/devfreq/Makefile
index 338ae8440db6..c2463ed4c934 100644
--- a/drivers/devfreq/Makefile
+++ b/drivers/devfreq/Makefile@@ -7,10 +7,11 @@ obj-$(CONFIG_DEVFREQ_GOV_POWERSAVE) += governor_powersave.o obj-$(CONFIG_DEVFREQ_GOV_USERSPACE) += governor_userspace.o obj-$(CONFIG_DEVFREQ_GOV_PASSIVE) += governor_passive.o # DEVFREQ Drivers obj-$(CONFIG_ARM_EXYNOS_BUS_DEVFREQ) += exynos-bus.o +obj-$(CONFIG_ARM_IMX_DEVFREQ) += imx-devfreq.o obj-$(CONFIG_ARM_RK3399_DMC_DEVFREQ) += rk3399_dmc.o obj-$(CONFIG_ARM_TEGRA_DEVFREQ) += tegra30-devfreq.o obj-$(CONFIG_ARM_TEGRA20_DEVFREQ) += tegra20-devfreq.o # DEVFREQ Event Drivers
diff --git a/drivers/devfreq/imx-devfreq.c b/drivers/devfreq/imx-devfreq.c
new file mode 100644
index 000000000000..aa8868d32f22
--- /dev/null
+++ b/drivers/devfreq/imx-devfreq.c@@ -0,0 +1,142 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2019 NXP + */ + +#include <linux/clk.h> +#include <linux/devfreq.h> +#include <linux/devfreq-event.h> +#include <linux/device.h> +#include <linux/module.h> +#include <linux/of_device.h> +#include <linux/pm_opp.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +struct imx_devfreq { + struct devfreq_dev_profile profile; + struct devfreq *devfreq; + struct clk *clk; +}; + +static int imx_devfreq_target(struct device *dev, unsigned long *freq, u32 flags) +{ + struct imx_devfreq *priv = dev_get_drvdata(dev); + struct dev_pm_opp *new_opp; + unsigned long new_freq; + int ret; + + new_opp = devfreq_recommended_opp(dev, freq, flags); + if (IS_ERR(new_opp)) { + ret = PTR_ERR(new_opp); + dev_err(dev, "failed to get recommended opp: %d\n", ret); + return ret; + } + new_freq = dev_pm_opp_get_freq(new_opp); + dev_pm_opp_put(new_opp); + + ret = clk_set_min_rate(priv->clk, new_freq); + if (ret) + return ret; + + ret = clk_set_rate(priv->clk, 0); + if (ret) { + clk_set_min_rate(priv->clk, priv->devfreq->previous_freq); + return ret; + } + + return 0; +} + +static int imx_devfreq_get_cur_freq(struct device *dev, unsigned long *freq) +{ + struct imx_devfreq *priv = dev_get_drvdata(dev); + + *freq = clk_get_rate(priv->clk); + + return 0; +} + +static int imx_devfreq_get_dev_status(struct device *dev, + struct devfreq_dev_status *stat) +{ + struct imx_devfreq *priv = dev_get_drvdata(dev); + + stat->busy_time = 0; + stat->total_time = 0; + stat->current_frequency = clk_get_rate(priv->clk); + + return 0; +} + +static void imx_devfreq_exit(struct device *dev) +{ + return dev_pm_opp_of_remove_table(dev); +} + +static int imx_devfreq_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct imx_devfreq *priv; + int ret; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->clk = devm_clk_get(dev, NULL); + if (IS_ERR(priv->devfreq)) { + ret = PTR_ERR(priv->devfreq); + dev_err(dev, "failed to fetch clk: %d\n", ret); + return ret; + } + platform_set_drvdata(pdev, priv); + + ret = dev_pm_opp_of_add_table(dev); + if (ret < 0) { + dev_err(dev, "failed to get OPP table\n"); + return ret; + } + + priv->profile.polling_ms = 1000; + priv->profile.target = imx_devfreq_target; + priv->profile.get_dev_status = imx_devfreq_get_dev_status; + priv->profile.exit = imx_devfreq_exit; + priv->profile.get_cur_freq = imx_devfreq_get_cur_freq; + priv->profile.initial_freq = clk_get_rate(priv->clk); + + priv->devfreq = devm_devfreq_add_device(dev, &priv->profile, + DEVFREQ_GOV_USERSPACE, + NULL); + if (IS_ERR(priv->devfreq)) { + ret = PTR_ERR(priv->devfreq); + dev_err(dev, "failed to add devfreq device: %d\n", ret); + goto err_remove_table; + } + + return 0; + +err_remove_table: + dev_pm_opp_of_remove_table(dev); + return ret; +} + +static const struct of_device_id imx_devfreq_of_match[] = { + { .compatible = "fsl,imx8mm-ddrc", }, + { .compatible = "fsl,imx8mm-noc", }, + { .compatible = "fsl,imx8mm-nic", }, + { /* sentinel */ }, +}; +MODULE_DEVICE_TABLE(of, imx_devfreq_of_match); + +static struct platform_driver imx_devfreq_platdrv = { + .probe = imx_devfreq_probe, + .driver = { + .name = "devfreq-imx", + .of_match_table = of_match_ptr(imx_devfreq_of_match), + }, +}; +module_platform_driver(imx_devfreq_platdrv); + +MODULE_DESCRIPTION("Generic i.MX bus frequency driver"); +MODULE_LICENSE("GPL v2");
--
2.17.1
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