root/drivers/interconnect/imx/imx.c
// SPDX-License-Identifier: GPL-2.0
/*
 * Interconnect framework driver for i.MX SoC
 *
 * Copyright (c) 2019, BayLibre
 * Copyright (c) 2019-2020, NXP
 * Author: Alexandre Bailon <abailon@baylibre.com>
 * Author: Leonard Crestez <leonard.crestez@nxp.com>
 */

#include <linux/device.h>
#include <linux/interconnect-provider.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pm_qos.h>

#include "imx.h"

/* private icc_node data */
struct imx_icc_node {
        const struct imx_icc_node_desc *desc;
        const struct imx_icc_noc_setting *setting;
        struct device *qos_dev;
        struct dev_pm_qos_request qos_req;
        struct imx_icc_provider *imx_provider;
};

static int imx_icc_get_bw(struct icc_node *node, u32 *avg, u32 *peak)
{
        *avg = 0;
        *peak = 0;

        return 0;
}

static int imx_icc_node_set(struct icc_node *node)
{
        struct device *dev = node->provider->dev;
        struct imx_icc_node *node_data = node->data;
        void __iomem *base;
        u32 prio;
        u64 freq;

        if (node_data->setting && node->peak_bw) {
                base = node_data->setting->reg + node_data->imx_provider->noc_base;
                if (node_data->setting->mode == IMX_NOC_MODE_FIXED) {
                        prio = node_data->setting->prio_level;
                        prio = PRIORITY_COMP_MARK | (prio << 8) | prio;
                        writel(prio, base + IMX_NOC_PRIO_REG);
                        writel(node_data->setting->mode, base + IMX_NOC_MODE_REG);
                        writel(node_data->setting->ext_control, base + IMX_NOC_EXT_CTL_REG);
                        dev_dbg(dev, "%s: mode: 0x%x, prio: 0x%x, ext_control: 0x%x\n",
                                node_data->desc->name, node_data->setting->mode, prio,
                                node_data->setting->ext_control);
                } else if (node_data->setting->mode == IMX_NOC_MODE_UNCONFIGURED) {
                        dev_dbg(dev, "%s: mode not unconfigured\n", node_data->desc->name);
                } else {
                        dev_info(dev, "%s: mode: %d not supported\n",
                                 node_data->desc->name, node_data->setting->mode);
                        return -EOPNOTSUPP;
                }
        }

        if (!node_data->qos_dev)
                return 0;

        freq = (node->avg_bw + node->peak_bw) * node_data->desc->adj->bw_mul;
        do_div(freq, node_data->desc->adj->bw_div);
        dev_dbg(dev, "node %s device %s avg_bw %ukBps peak_bw %ukBps min_freq %llukHz\n",
                node->name, dev_name(node_data->qos_dev),
                node->avg_bw, node->peak_bw, freq);

        if (freq > S32_MAX) {
                dev_err(dev, "%s can't request more than S32_MAX freq\n",
                                node->name);
                return -ERANGE;
        }

        dev_pm_qos_update_request(&node_data->qos_req, freq);

        return 0;
}

static int imx_icc_set(struct icc_node *src, struct icc_node *dst)
{
        int ret;

        ret = imx_icc_node_set(src);
        if (ret)
                return ret;

        return imx_icc_node_set(dst);
}

/* imx_icc_node_destroy() - Destroy an imx icc_node, including private data */
static void imx_icc_node_destroy(struct icc_node *node)
{
        struct imx_icc_node *node_data = node->data;
        int ret;

        if (dev_pm_qos_request_active(&node_data->qos_req)) {
                ret = dev_pm_qos_remove_request(&node_data->qos_req);
                if (ret)
                        dev_warn(node->provider->dev,
                                 "failed to remove qos request for %s\n",
                                 dev_name(node_data->qos_dev));
        }

        put_device(node_data->qos_dev);
        icc_node_del(node);
        icc_node_destroy(node->id);
}

static int imx_icc_node_init_qos(struct icc_provider *provider,
                                 struct icc_node *node)
{
        struct imx_icc_node *node_data = node->data;
        const struct imx_icc_node_adj_desc *adj = node_data->desc->adj;
        struct device *dev = provider->dev;
        struct device_node *dn = NULL;
        struct platform_device *pdev;

        if (adj->main_noc) {
                node_data->qos_dev = dev;
                dev_dbg(dev, "icc node %s[%d] is main noc itself\n",
                        node->name, node->id);
        } else {
                dn = of_parse_phandle(dev->of_node, adj->phandle_name, 0);
                if (!dn) {
                        dev_warn(dev, "Failed to parse %s\n",
                                 adj->phandle_name);
                        return -ENODEV;
                }
                /* Allow scaling to be disabled on a per-node basis */
                if (!of_device_is_available(dn)) {
                        dev_warn(dev, "Missing property %s, skip scaling %s\n",
                                 adj->phandle_name, node->name);
                        of_node_put(dn);
                        return 0;
                }

                pdev = of_find_device_by_node(dn);
                of_node_put(dn);
                if (!pdev) {
                        dev_warn(dev, "node %s[%d] missing device for %pOF\n",
                                 node->name, node->id, dn);
                        return -EPROBE_DEFER;
                }
                node_data->qos_dev = &pdev->dev;
                dev_dbg(dev, "node %s[%d] has device node %pOF\n",
                        node->name, node->id, dn);
        }

        return dev_pm_qos_add_request(node_data->qos_dev,
                                      &node_data->qos_req,
                                      DEV_PM_QOS_MIN_FREQUENCY, 0);
}

static struct icc_node *imx_icc_node_add(struct imx_icc_provider *imx_provider,
                                         const struct imx_icc_node_desc *node_desc,
                                         const struct imx_icc_noc_setting *setting)
{
        struct icc_provider *provider = &imx_provider->provider;
        struct device *dev = provider->dev;
        struct imx_icc_node *node_data;
        struct icc_node *node;
        int ret;

        node = icc_node_create(node_desc->id);
        if (IS_ERR(node)) {
                dev_err(dev, "failed to create node %d\n", node_desc->id);
                return node;
        }

        if (node->data) {
                dev_err(dev, "already created node %s id=%d\n",
                        node_desc->name, node_desc->id);
                return ERR_PTR(-EEXIST);
        }

        node_data = devm_kzalloc(dev, sizeof(*node_data), GFP_KERNEL);
        if (!node_data) {
                icc_node_destroy(node->id);
                return ERR_PTR(-ENOMEM);
        }

        node->name = node_desc->name;
        node->data = node_data;
        node_data->desc = node_desc;
        node_data->setting = setting;
        node_data->imx_provider = imx_provider;
        icc_node_add(node, provider);

        if (node_desc->adj) {
                ret = imx_icc_node_init_qos(provider, node);
                if (ret < 0) {
                        imx_icc_node_destroy(node);
                        return ERR_PTR(ret);
                }
        }

        return node;
}

static void imx_icc_unregister_nodes(struct icc_provider *provider)
{
        struct icc_node *node, *tmp;

        list_for_each_entry_safe(node, tmp, &provider->nodes, node_list)
                imx_icc_node_destroy(node);
}

static int imx_icc_register_nodes(struct imx_icc_provider *imx_provider,
                                  const struct imx_icc_node_desc *descs,
                                  int count,
                                  const struct imx_icc_noc_setting *settings)
{
        struct icc_provider *provider = &imx_provider->provider;
        struct icc_onecell_data *provider_data = provider->data;
        int ret;
        int i;

        for (i = 0; i < count; i++) {
                struct icc_node *node;
                const struct imx_icc_node_desc *node_desc = &descs[i];
                size_t j;

                node = imx_icc_node_add(imx_provider, node_desc,
                                        settings ? &settings[node_desc->id] : NULL);
                if (IS_ERR(node)) {
                        ret = dev_err_probe(provider->dev, PTR_ERR(node),
                                            "failed to add %s\n", node_desc->name);
                        goto err;
                }
                provider_data->nodes[node->id] = node;

                for (j = 0; j < node_desc->num_links; j++) {
                        ret = icc_link_create(node, node_desc->links[j]);
                        if (ret) {
                                dev_err(provider->dev, "failed to link node %d to %d: %d\n",
                                        node->id, node_desc->links[j], ret);
                                goto err;
                        }
                }
        }

        return 0;

err:
        imx_icc_unregister_nodes(provider);

        return ret;
}

static int get_max_node_id(struct imx_icc_node_desc *nodes, int nodes_count)
{
        int i, ret = 0;

        for (i = 0; i < nodes_count; ++i)
                if (nodes[i].id > ret)
                        ret = nodes[i].id;

        return ret;
}

int imx_icc_register(struct platform_device *pdev,
                     struct imx_icc_node_desc *nodes, int nodes_count,
                     struct imx_icc_noc_setting *settings)
{
        struct device *dev = &pdev->dev;
        struct icc_onecell_data *data;
        struct imx_icc_provider *imx_provider;
        struct icc_provider *provider;
        int num_nodes;
        int ret;

        /* icc_onecell_data is indexed by node_id, unlike nodes param */
        num_nodes = get_max_node_id(nodes, nodes_count) + 1;
        data = devm_kzalloc(dev, struct_size(data, nodes, num_nodes),
                            GFP_KERNEL);
        if (!data)
                return -ENOMEM;
        data->num_nodes = num_nodes;

        imx_provider = devm_kzalloc(dev, sizeof(*imx_provider), GFP_KERNEL);
        if (!imx_provider)
                return -ENOMEM;
        provider = &imx_provider->provider;
        provider->set = imx_icc_set;
        provider->get_bw = imx_icc_get_bw;
        provider->aggregate = icc_std_aggregate;
        provider->xlate = of_icc_xlate_onecell;
        provider->data = data;
        provider->dev = dev->parent;

        icc_provider_init(provider);

        platform_set_drvdata(pdev, imx_provider);

        if (settings) {
                imx_provider->noc_base = devm_of_iomap(dev, provider->dev->of_node, 0, NULL);
                if (IS_ERR(imx_provider->noc_base)) {
                        ret = PTR_ERR(imx_provider->noc_base);
                        dev_err(dev, "Error mapping NoC: %d\n", ret);
                        return ret;
                }
        }

        ret = imx_icc_register_nodes(imx_provider, nodes, nodes_count, settings);
        if (ret)
                return ret;

        ret = icc_provider_register(provider);
        if (ret)
                goto err_unregister_nodes;

        return 0;

err_unregister_nodes:
        imx_icc_unregister_nodes(&imx_provider->provider);
        return ret;
}
EXPORT_SYMBOL_GPL(imx_icc_register);

void imx_icc_unregister(struct platform_device *pdev)
{
        struct imx_icc_provider *imx_provider = platform_get_drvdata(pdev);

        icc_provider_deregister(&imx_provider->provider);
        imx_icc_unregister_nodes(&imx_provider->provider);
}
EXPORT_SYMBOL_GPL(imx_icc_unregister);

MODULE_DESCRIPTION("Interconnect framework driver for i.MX SoC");
MODULE_LICENSE("GPL v2");