1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright 2019 NXP 4 */ 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 15 struct imx_bus { 16 struct devfreq_dev_profile profile; 17 struct devfreq *devfreq; 18 struct clk *clk; 19 struct platform_device *icc_pdev; 20 }; 21 22 static 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 39 static 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 48 static 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 */ 57 static 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_get_property(dev->of_node, "#interconnect-cells", NULL)) 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 86 static 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 on 101 * or off and some peripheral side-buses might be off unless enabled by 102 * 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; 138 139 err: 140 dev_pm_opp_of_remove_table(dev); 141 return ret; 142 } 143 144 static 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 }; 153 MODULE_DEVICE_TABLE(of, imx_bus_of_match); 154 155 static 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 }; 162 module_platform_driver(imx_bus_platdrv); 163 164 MODULE_DESCRIPTION("Generic i.MX bus frequency scaling driver"); 165 MODULE_AUTHOR("Leonard Crestez <leonard.crestez@nxp.com>"); 166 MODULE_LICENSE("GPL v2"); 167