PM / devfreq: Add generic imx bus scaling driver (5173a975) · Commits · 戴 / test

drivers/devfreq/Kconfig

+8 −0

Original line number	Diff line number	Diff line
		@@ -91,6 +91,14 @@ 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_IMX_BUS_DEVFREQ
		tristate "i.MX Generic Bus DEVFREQ Driver"
		depends on ARCH_MXC \|\| COMPILE_TEST
		select DEVFREQ_GOV_USERSPACE
		help
		This adds the generic DEVFREQ driver for i.MX interconnects. It
		allows adjusting NIC/NOC frequency.

		config ARM_IMX8M_DDRC_DEVFREQ
		tristate "i.MX8M DDRC DEVFREQ Driver"
		depends on (ARCH_MXC && HAVE_ARM_SMCCC) \|\| \

drivers/devfreq/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -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_IMX_BUS_DEVFREQ) += imx-bus.o
		obj-$(CONFIG_ARM_IMX8M_DDRC_DEVFREQ) += imx8m-ddrc.o
		obj-$(CONFIG_ARM_RK3399_DMC_DEVFREQ) += rk3399_dmc.o
		obj-$(CONFIG_ARM_TEGRA_DEVFREQ) += tegra30-devfreq.o

drivers/devfreq/imx-bus.c

0 → 100644

+138 −0

Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0
		/*
		* Copyright 2019 NXP
		*/

		#include <linux/clk.h>
		#include <linux/devfreq.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_bus {
		struct devfreq_dev_profile profile;
		struct devfreq *devfreq;
		struct clk *clk;
		};

		static int imx_bus_target(struct device *dev,
		unsigned long *freq, u32 flags)
		{
		struct dev_pm_opp *new_opp;
		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;
		}
		dev_pm_opp_put(new_opp);

		return dev_pm_opp_set_rate(dev, *freq);
		}

		static int imx_bus_get_cur_freq(struct device dev, unsigned long freq)
		{
		struct imx_bus *priv = dev_get_drvdata(dev);

		*freq = clk_get_rate(priv->clk);

		return 0;
		}

		static int imx_bus_get_dev_status(struct device *dev,
		struct devfreq_dev_status *stat)
		{
		struct imx_bus *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_bus_exit(struct device *dev)
		{
		dev_pm_opp_of_remove_table(dev);
		}

		static int imx_bus_probe(struct platform_device *pdev)
		{
		struct device *dev = &pdev->dev;
		struct imx_bus *priv;
		const char *gov = DEVFREQ_GOV_USERSPACE;
		int ret;

		priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
		if (!priv)
		return -ENOMEM;

		/*
		* Fetch the clock to adjust but don't explicitly enable.
		*
		* For imx bus clock clk_set_rate is safe no matter if the clock is on
		* or off and some peripheral side-buses might be off unless enabled by
		* drivers for devices on those specific buses.
		*
		* Rate adjustment on a disabled bus clock just takes effect later.
		*/
		priv->clk = devm_clk_get(dev, NULL);
		if (IS_ERR(priv->clk)) {
		ret = PTR_ERR(priv->clk);
		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_bus_target;
		priv->profile.get_dev_status = imx_bus_get_dev_status;
		priv->profile.exit = imx_bus_exit;
		priv->profile.get_cur_freq = imx_bus_get_cur_freq;
		priv->profile.initial_freq = clk_get_rate(priv->clk);

		priv->devfreq = devm_devfreq_add_device(dev, &priv->profile,
		gov, NULL);
		if (IS_ERR(priv->devfreq)) {
		ret = PTR_ERR(priv->devfreq);
		dev_err(dev, "failed to add devfreq device: %d\n", ret);
		goto err;
		}

		return 0;

		err:
		dev_pm_opp_of_remove_table(dev);
		return ret;
		}

		static const struct of_device_id imx_bus_of_match[] = {
		{ .compatible = "fsl,imx8m-noc", },
		{ .compatible = "fsl,imx8m-nic", },
		{ /* sentinel */ },
		};
		MODULE_DEVICE_TABLE(of, imx_bus_of_match);

		static struct platform_driver imx_bus_platdrv = {
		.probe = imx_bus_probe,
		.driver = {
		.name = "imx-bus-devfreq",
		.of_match_table = of_match_ptr(imx_bus_of_match),
		},
		};
		module_platform_driver(imx_bus_platdrv);

		MODULE_DESCRIPTION("Generic i.MX bus frequency scaling driver");
		MODULE_AUTHOR("Leonard Crestez <leonard.crestez@nxp.com>");
		MODULE_LICENSE("GPL v2");

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