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| 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_device.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 int imx_bus_get_dev_status(struct device *dev, |
| 49 | + struct devfreq_dev_status *stat) |
| 50 | +{ |
| 51 | + struct imx_bus *priv = dev_get_drvdata(dev); |
| 52 | + |
| 53 | + stat->busy_time = 0; |
| 54 | + stat->total_time = 0; |
| 55 | + stat->current_frequency = clk_get_rate(priv->clk); |
| 56 | + |
| 57 | + return 0; |
| 58 | +} |
| 59 | + |
| 60 | +static void imx_bus_exit(struct device *dev) |
| 61 | +{ |
| 62 | + struct imx_bus *priv = dev_get_drvdata(dev); |
| 63 | + |
| 64 | + dev_pm_opp_of_remove_table(dev); |
| 65 | + platform_device_unregister(priv->icc_pdev); |
| 66 | +} |
| 67 | + |
| 68 | +/* imx_bus_init_icc() - register matching icc provider if required */ |
| 69 | +static int imx_bus_init_icc(struct device *dev) |
| 70 | +{ |
| 71 | + struct imx_bus *priv = dev_get_drvdata(dev); |
| 72 | + const char *icc_driver_name; |
| 73 | + |
| 74 | + if (!of_get_property(dev->of_node, "#interconnect-cells", 0)) |
| 75 | + return 0; |
| 76 | + if (!IS_ENABLED(CONFIG_INTERCONNECT_IMX)) { |
| 77 | + dev_warn(dev, "imx interconnect drivers disabled\n"); |
| 78 | + return 0; |
| 79 | + } |
| 80 | + |
| 81 | + icc_driver_name = of_device_get_match_data(dev); |
| 82 | + if (!icc_driver_name) { |
| 83 | + dev_err(dev, "unknown interconnect driver\n"); |
| 84 | + return 0; |
| 85 | + } |
| 86 | + |
| 87 | + priv->icc_pdev = platform_device_register_data( |
| 88 | + dev, icc_driver_name, -1, NULL, 0); |
| 89 | + if (IS_ERR(priv->icc_pdev)) { |
| 90 | + dev_err(dev, "failed to register icc provider %s: %ld\n", |
| 91 | + icc_driver_name, PTR_ERR(priv->icc_pdev)); |
| 92 | + return PTR_ERR(priv->icc_pdev); |
| 93 | + } |
| 94 | + |
| 95 | + return 0; |
| 96 | +} |
| 97 | + |
| 98 | +static int imx_bus_probe(struct platform_device *pdev) |
| 99 | +{ |
| 100 | + struct device *dev = &pdev->dev; |
| 101 | + struct imx_bus *priv; |
| 102 | + const char *gov = DEVFREQ_GOV_USERSPACE; |
| 103 | + int ret; |
| 104 | + |
| 105 | + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); |
| 106 | + if (!priv) |
| 107 | + return -ENOMEM; |
| 108 | + |
| 109 | + /* |
| 110 | + * Fetch the clock to adjust but don't explicitly enable. |
| 111 | + * |
| 112 | + * For imx bus clock clk_set_rate is safe no matter if the clock is on |
| 113 | + * or off and some peripheral side-buses might be off unless enabled by |
| 114 | + * drivers for devices on those specific buses. |
| 115 | + * |
| 116 | + * Rate adjustment on a disabled bus clock just takes effect later. |
| 117 | + */ |
| 118 | + priv->clk = devm_clk_get(dev, NULL); |
| 119 | + if (IS_ERR(priv->clk)) { |
| 120 | + ret = PTR_ERR(priv->clk); |
| 121 | + dev_err(dev, "failed to fetch clk: %d\n", ret); |
| 122 | + return ret; |
| 123 | + } |
| 124 | + platform_set_drvdata(pdev, priv); |
| 125 | + |
| 126 | + ret = dev_pm_opp_of_add_table(dev); |
| 127 | + if (ret < 0) { |
| 128 | + dev_err(dev, "failed to get OPP table\n"); |
| 129 | + return ret; |
| 130 | + } |
| 131 | + |
| 132 | + priv->profile.polling_ms = 1000; |
| 133 | + priv->profile.target = imx_bus_target; |
| 134 | + priv->profile.get_dev_status = imx_bus_get_dev_status; |
| 135 | + priv->profile.exit = imx_bus_exit; |
| 136 | + priv->profile.get_cur_freq = imx_bus_get_cur_freq; |
| 137 | + priv->profile.initial_freq = clk_get_rate(priv->clk); |
| 138 | + |
| 139 | + priv->devfreq = devm_devfreq_add_device(dev, &priv->profile, |
| 140 | + gov, NULL); |
| 141 | + if (IS_ERR(priv->devfreq)) { |
| 142 | + ret = PTR_ERR(priv->devfreq); |
| 143 | + dev_err(dev, "failed to add devfreq device: %d\n", ret); |
| 144 | + goto err; |
| 145 | + } |
| 146 | + |
| 147 | + ret = imx_bus_init_icc(dev); |
| 148 | + if (ret) |
| 149 | + goto err; |
| 150 | + |
| 151 | + return 0; |
| 152 | + |
| 153 | +err: |
| 154 | + dev_pm_opp_of_remove_table(dev); |
| 155 | + return ret; |
| 156 | +} |
| 157 | + |
| 158 | +static const struct of_device_id imx_bus_of_match[] = { |
| 159 | + { .compatible = "fsl,imx8mq-noc", .data = "imx8mq-interconnect", }, |
| 160 | + { .compatible = "fsl,imx8mm-noc", .data = "imx8mm-interconnect", }, |
| 161 | + { .compatible = "fsl,imx8mn-noc", .data = "imx8mn-interconnect", }, |
| 162 | + { .compatible = "fsl,imx8m-noc", }, |
| 163 | + { .compatible = "fsl,imx8m-nic", }, |
| 164 | + { /* sentinel */ }, |
| 165 | +}; |
| 166 | +MODULE_DEVICE_TABLE(of, imx_bus_of_match); |
| 167 | + |
| 168 | +static struct platform_driver imx_bus_platdrv = { |
| 169 | + .probe = imx_bus_probe, |
| 170 | + .driver = { |
| 171 | + .name = "imx-bus-devfreq", |
| 172 | + .of_match_table = of_match_ptr(imx_bus_of_match), |
| 173 | + }, |
| 174 | +}; |
| 175 | +module_platform_driver(imx_bus_platdrv); |
| 176 | + |
| 177 | +MODULE_DESCRIPTION("Generic i.MX bus frequency scaling driver"); |
| 178 | +MODULE_AUTHOR( "Leonard Crestez <[email protected]>"); |
| 179 | +MODULE_LICENSE("GPL v2"); |
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