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1// SPDX-License-Identifier: GPL-2.02/*3 * Copyright 2019 NXP4 */5 6#include <linux/clk.h>7#include <linux/devfreq.h>8#include <linux/device.h>9#include <linux/module.h>10#include <linux/of.h>11#include <linux/pm_opp.h>12#include <linux/platform_device.h>13#include <linux/slab.h>14 15struct imx_bus {16 struct devfreq_dev_profile profile;17 struct devfreq *devfreq;18 struct clk *clk;19 struct platform_device *icc_pdev;20};21 22static int imx_bus_target(struct device *dev,23 unsigned long *freq, u32 flags)24{25 struct dev_pm_opp *new_opp;26 int ret;27 28 new_opp = devfreq_recommended_opp(dev, freq, flags);29 if (IS_ERR(new_opp)) {30 ret = PTR_ERR(new_opp);31 dev_err(dev, "failed to get recommended opp: %d\n", ret);32 return ret;33 }34 dev_pm_opp_put(new_opp);35 36 return dev_pm_opp_set_rate(dev, *freq);37}38 39static int imx_bus_get_cur_freq(struct device *dev, unsigned long *freq)40{41 struct imx_bus *priv = dev_get_drvdata(dev);42 43 *freq = clk_get_rate(priv->clk);44 45 return 0;46}47 48static void imx_bus_exit(struct device *dev)49{50 struct imx_bus *priv = dev_get_drvdata(dev);51 52 dev_pm_opp_of_remove_table(dev);53 platform_device_unregister(priv->icc_pdev);54}55 56/* imx_bus_init_icc() - register matching icc provider if required */57static int imx_bus_init_icc(struct device *dev)58{59 struct imx_bus *priv = dev_get_drvdata(dev);60 const char *icc_driver_name;61 62 if (!of_property_present(dev->of_node, "#interconnect-cells"))63 return 0;64 if (!IS_ENABLED(CONFIG_INTERCONNECT_IMX)) {65 dev_warn(dev, "imx interconnect drivers disabled\n");66 return 0;67 }68 69 icc_driver_name = of_device_get_match_data(dev);70 if (!icc_driver_name) {71 dev_err(dev, "unknown interconnect driver\n");72 return 0;73 }74 75 priv->icc_pdev = platform_device_register_data(76 dev, icc_driver_name, -1, NULL, 0);77 if (IS_ERR(priv->icc_pdev)) {78 dev_err(dev, "failed to register icc provider %s: %ld\n",79 icc_driver_name, PTR_ERR(priv->icc_pdev));80 return PTR_ERR(priv->icc_pdev);81 }82 83 return 0;84}85 86static int imx_bus_probe(struct platform_device *pdev)87{88 struct device *dev = &pdev->dev;89 struct imx_bus *priv;90 const char *gov = DEVFREQ_GOV_USERSPACE;91 int ret;92 93 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);94 if (!priv)95 return -ENOMEM;96 97 /*98 * Fetch the clock to adjust but don't explicitly enable.99 *100 * For imx bus clock clk_set_rate is safe no matter if the clock is on101 * or off and some peripheral side-buses might be off unless enabled by102 * drivers for devices on those specific buses.103 *104 * Rate adjustment on a disabled bus clock just takes effect later.105 */106 priv->clk = devm_clk_get(dev, NULL);107 if (IS_ERR(priv->clk)) {108 ret = PTR_ERR(priv->clk);109 dev_err(dev, "failed to fetch clk: %d\n", ret);110 return ret;111 }112 platform_set_drvdata(pdev, priv);113 114 ret = dev_pm_opp_of_add_table(dev);115 if (ret < 0) {116 dev_err(dev, "failed to get OPP table\n");117 return ret;118 }119 120 priv->profile.target = imx_bus_target;121 priv->profile.exit = imx_bus_exit;122 priv->profile.get_cur_freq = imx_bus_get_cur_freq;123 priv->profile.initial_freq = clk_get_rate(priv->clk);124 125 priv->devfreq = devm_devfreq_add_device(dev, &priv->profile,126 gov, NULL);127 if (IS_ERR(priv->devfreq)) {128 ret = PTR_ERR(priv->devfreq);129 dev_err(dev, "failed to add devfreq device: %d\n", ret);130 goto err;131 }132 133 ret = imx_bus_init_icc(dev);134 if (ret)135 goto err;136 137 return 0;138 139err:140 dev_pm_opp_of_remove_table(dev);141 return ret;142}143 144static const struct of_device_id imx_bus_of_match[] = {145 { .compatible = "fsl,imx8mq-noc", .data = "imx8mq-interconnect", },146 { .compatible = "fsl,imx8mm-noc", .data = "imx8mm-interconnect", },147 { .compatible = "fsl,imx8mn-noc", .data = "imx8mn-interconnect", },148 { .compatible = "fsl,imx8mp-noc", .data = "imx8mp-interconnect", },149 { .compatible = "fsl,imx8m-noc", },150 { .compatible = "fsl,imx8m-nic", },151 { /* sentinel */ },152};153MODULE_DEVICE_TABLE(of, imx_bus_of_match);154 155static struct platform_driver imx_bus_platdrv = {156 .probe = imx_bus_probe,157 .driver = {158 .name = "imx-bus-devfreq",159 .of_match_table = imx_bus_of_match,160 },161};162module_platform_driver(imx_bus_platdrv);163 164MODULE_DESCRIPTION("Generic i.MX bus frequency scaling driver");165MODULE_AUTHOR("Leonard Crestez <leonard.crestez@nxp.com>");166MODULE_LICENSE("GPL v2");167