1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Exynos generic interconnect provider driver 4 * 5 * Copyright (c) 2020 Samsung Electronics Co., Ltd. 6 * 7 * Authors: Artur Świgoń <a.swigon@samsung.com> 8 * Sylwester Nawrocki <s.nawrocki@samsung.com> 9 */ 10 #include <linux/device.h> 11 #include <linux/interconnect-provider.h> 12 #include <linux/module.h> 13 #include <linux/of.h> 14 #include <linux/platform_device.h> 15 #include <linux/pm_qos.h> 16 #include <linux/slab.h> 17 18 #define EXYNOS_ICC_DEFAULT_BUS_CLK_RATIO 8 19 20 struct exynos_icc_priv { 21 struct device *dev; 22 23 /* One interconnect node per provider */ 24 struct icc_provider provider; 25 struct icc_node *node; 26 27 struct dev_pm_qos_request qos_req; 28 u32 bus_clk_ratio; 29 }; 30 31 static struct icc_node *exynos_icc_get_parent(struct device_node *np) 32 { 33 struct of_phandle_args args; 34 struct icc_node_data *icc_node_data; 35 struct icc_node *icc_node; 36 int num, ret; 37 38 num = of_count_phandle_with_args(np, "interconnects", 39 "#interconnect-cells"); 40 if (num < 1) 41 return NULL; /* parent nodes are optional */ 42 43 /* Get the interconnect target node */ 44 ret = of_parse_phandle_with_args(np, "interconnects", 45 "#interconnect-cells", 0, &args); 46 if (ret < 0) 47 return ERR_PTR(ret); 48 49 icc_node_data = of_icc_get_from_provider(&args); 50 of_node_put(args.np); 51 52 if (IS_ERR(icc_node_data)) 53 return ERR_CAST(icc_node_data); 54 55 icc_node = icc_node_data->node; 56 kfree(icc_node_data); 57 58 return icc_node; 59 } 60 61 static int exynos_generic_icc_set(struct icc_node *src, struct icc_node *dst) 62 { 63 struct exynos_icc_priv *src_priv = src->data, *dst_priv = dst->data; 64 s32 src_freq = max(src->avg_bw, src->peak_bw) / src_priv->bus_clk_ratio; 65 s32 dst_freq = max(dst->avg_bw, dst->peak_bw) / dst_priv->bus_clk_ratio; 66 int ret; 67 68 ret = dev_pm_qos_update_request(&src_priv->qos_req, src_freq); 69 if (ret < 0) { 70 dev_err(src_priv->dev, "failed to update PM QoS of %s (src)\n", 71 src->name); 72 return ret; 73 } 74 75 ret = dev_pm_qos_update_request(&dst_priv->qos_req, dst_freq); 76 if (ret < 0) { 77 dev_err(dst_priv->dev, "failed to update PM QoS of %s (dst)\n", 78 dst->name); 79 return ret; 80 } 81 82 return 0; 83 } 84 85 static struct icc_node *exynos_generic_icc_xlate(struct of_phandle_args *spec, 86 void *data) 87 { 88 struct exynos_icc_priv *priv = data; 89 90 if (spec->np != priv->dev->parent->of_node) 91 return ERR_PTR(-EINVAL); 92 93 return priv->node; 94 } 95 96 static int exynos_generic_icc_remove(struct platform_device *pdev) 97 { 98 struct exynos_icc_priv *priv = platform_get_drvdata(pdev); 99 100 icc_provider_deregister(&priv->provider); 101 icc_nodes_remove(&priv->provider); 102 103 return 0; 104 } 105 106 static int exynos_generic_icc_probe(struct platform_device *pdev) 107 { 108 struct device *bus_dev = pdev->dev.parent; 109 struct exynos_icc_priv *priv; 110 struct icc_provider *provider; 111 struct icc_node *icc_node, *icc_parent_node; 112 int ret; 113 114 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); 115 if (!priv) 116 return -ENOMEM; 117 118 priv->dev = &pdev->dev; 119 platform_set_drvdata(pdev, priv); 120 121 provider = &priv->provider; 122 123 provider->set = exynos_generic_icc_set; 124 provider->aggregate = icc_std_aggregate; 125 provider->xlate = exynos_generic_icc_xlate; 126 provider->dev = bus_dev; 127 provider->inter_set = true; 128 provider->data = priv; 129 130 icc_provider_init(provider); 131 132 icc_node = icc_node_create(pdev->id); 133 if (IS_ERR(icc_node)) 134 return PTR_ERR(icc_node); 135 136 priv->node = icc_node; 137 icc_node->name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%pOFn", 138 bus_dev->of_node); 139 if (of_property_read_u32(bus_dev->of_node, "samsung,data-clock-ratio", 140 &priv->bus_clk_ratio)) 141 priv->bus_clk_ratio = EXYNOS_ICC_DEFAULT_BUS_CLK_RATIO; 142 143 icc_node->data = priv; 144 icc_node_add(icc_node, provider); 145 146 /* 147 * Register a PM QoS request for the parent (devfreq) device. 148 */ 149 ret = dev_pm_qos_add_request(bus_dev, &priv->qos_req, 150 DEV_PM_QOS_MIN_FREQUENCY, 0); 151 if (ret < 0) 152 goto err_node_del; 153 154 icc_parent_node = exynos_icc_get_parent(bus_dev->of_node); 155 if (IS_ERR(icc_parent_node)) { 156 ret = PTR_ERR(icc_parent_node); 157 goto err_pmqos_del; 158 } 159 if (icc_parent_node) { 160 ret = icc_link_create(icc_node, icc_parent_node->id); 161 if (ret < 0) 162 goto err_pmqos_del; 163 } 164 165 ret = icc_provider_register(provider); 166 if (ret < 0) 167 goto err_pmqos_del; 168 169 return 0; 170 171 err_pmqos_del: 172 dev_pm_qos_remove_request(&priv->qos_req); 173 err_node_del: 174 icc_nodes_remove(provider); 175 176 return ret; 177 } 178 179 static struct platform_driver exynos_generic_icc_driver = { 180 .driver = { 181 .name = "exynos-generic-icc", 182 .sync_state = icc_sync_state, 183 }, 184 .probe = exynos_generic_icc_probe, 185 .remove = exynos_generic_icc_remove, 186 }; 187 module_platform_driver(exynos_generic_icc_driver); 188 189 MODULE_DESCRIPTION("Exynos generic interconnect driver"); 190 MODULE_AUTHOR("Artur Świgoń <a.swigon@samsung.com>"); 191 MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki@samsung.com>"); 192 MODULE_LICENSE("GPL v2"); 193 MODULE_ALIAS("platform:exynos-generic-icc"); 194