samsung/exynos.c

   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");