linux/drivers/interconnect/samsung/exynos.c
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   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 \xC5\x9Awigo\xC5\x84 <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
  20struct 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
  31static 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
  61static 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
  85static 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
  96static int exynos_generic_icc_remove(struct platform_device *pdev)
  97{
  98        struct exynos_icc_priv *priv = platform_get_drvdata(pdev);
  99        struct icc_node *parent_node, *node = priv->node;
 100
 101        parent_node = exynos_icc_get_parent(priv->dev->parent->of_node);
 102        if (parent_node && !IS_ERR(parent_node))
 103                icc_link_destroy(node, parent_node);
 104
 105        icc_nodes_remove(&priv->provider);
 106        icc_provider_del(&priv->provider);
 107
 108        return 0;
 109}
 110
 111static int exynos_generic_icc_probe(struct platform_device *pdev)
 112{
 113        struct device *bus_dev = pdev->dev.parent;
 114        struct exynos_icc_priv *priv;
 115        struct icc_provider *provider;
 116        struct icc_node *icc_node, *icc_parent_node;
 117        int ret;
 118
 119        priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 120        if (!priv)
 121                return -ENOMEM;
 122
 123        priv->dev = &pdev->dev;
 124        platform_set_drvdata(pdev, priv);
 125
 126        provider = &priv->provider;
 127
 128        provider->set = exynos_generic_icc_set;
 129        provider->aggregate = icc_std_aggregate;
 130        provider->xlate = exynos_generic_icc_xlate;
 131        provider->dev = bus_dev;
 132        provider->inter_set = true;
 133        provider->data = priv;
 134
 135        ret = icc_provider_add(provider);
 136        if (ret < 0)
 137                return ret;
 138
 139        icc_node = icc_node_create(pdev->id);
 140        if (IS_ERR(icc_node)) {
 141                ret = PTR_ERR(icc_node);
 142                goto err_prov_del;
 143        }
 144
 145        priv->node = icc_node;
 146        icc_node->name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%pOFn",
 147                                        bus_dev->of_node);
 148        if (of_property_read_u32(bus_dev->of_node, "samsung,data-clock-ratio",
 149                                 &priv->bus_clk_ratio))
 150                priv->bus_clk_ratio = EXYNOS_ICC_DEFAULT_BUS_CLK_RATIO;
 151
 152        /*
 153         * Register a PM QoS request for the parent (devfreq) device.
 154         */
 155        ret = dev_pm_qos_add_request(bus_dev, &priv->qos_req,
 156                                     DEV_PM_QOS_MIN_FREQUENCY, 0);
 157        if (ret < 0)
 158                goto err_node_del;
 159
 160        icc_node->data = priv;
 161        icc_node_add(icc_node, provider);
 162
 163        icc_parent_node = exynos_icc_get_parent(bus_dev->of_node);
 164        if (IS_ERR(icc_parent_node)) {
 165                ret = PTR_ERR(icc_parent_node);
 166                goto err_pmqos_del;
 167        }
 168        if (icc_parent_node) {
 169                ret = icc_link_create(icc_node, icc_parent_node->id);
 170                if (ret < 0)
 171                        goto err_pmqos_del;
 172        }
 173
 174        return 0;
 175
 176err_pmqos_del:
 177        dev_pm_qos_remove_request(&priv->qos_req);
 178err_node_del:
 179        icc_nodes_remove(provider);
 180err_prov_del:
 181        icc_provider_del(provider);
 182        return ret;
 183}
 184
 185static struct platform_driver exynos_generic_icc_driver = {
 186        .driver = {
 187                .name = "exynos-generic-icc",
 188                .sync_state = icc_sync_state,
 189        },
 190        .probe = exynos_generic_icc_probe,
 191        .remove = exynos_generic_icc_remove,
 192};
 193module_platform_driver(exynos_generic_icc_driver);
 194
 195MODULE_DESCRIPTION("Exynos generic interconnect driver");
 196MODULE_AUTHOR("Artur \xC5\x9Awigo\xC5\x84 <a.swigon@samsung.com>");
 197MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki@samsung.com>");
 198MODULE_LICENSE("GPL v2");
 199MODULE_ALIAS("platform:exynos-generic-icc");
 200