// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
// Copyright(c) 2015-17 Intel Corporation.

#include <linux/acpi.h>
#include <linux/of.h>
#include <linux/soundwire/sdw.h>
#include <linux/soundwire/sdw_type.h>
#include "bus.h"

static void sdw_slave_release(struct device *dev)
{
        struct sdw_slave *slave = dev_to_sdw_dev(dev);

        kfree(slave);
}

static int sdw_slave_add(struct sdw_bus *bus,
                         struct sdw_slave_id *id, struct fwnode_handle *fwnode)
{
        struct sdw_slave *slave;
        int ret;

        slave = kzalloc(sizeof(*slave), GFP_KERNEL);
        if (!slave)
                return -ENOMEM;

        /* Initialize data structure */
        memcpy(&slave->id, id, sizeof(*id));
        slave->dev.parent = bus->dev;
        slave->dev.fwnode = fwnode;

        if (id->unique_id == SDW_IGNORED_UNIQUE_ID) {
                /* name shall be sdw:link:mfg:part:class */
                dev_set_name(&slave->dev, "sdw:%x:%x:%x:%x",
                             bus->link_id, id->mfg_id, id->part_id,
                             id->class_id);
        } else {
                /* name shall be sdw:link:mfg:part:class:unique */
                dev_set_name(&slave->dev, "sdw:%x:%x:%x:%x:%x",
                             bus->link_id, id->mfg_id, id->part_id,
                             id->class_id, id->unique_id);
        }

        slave->dev.release = sdw_slave_release;
        slave->dev.bus = &sdw_bus_type;
        slave->dev.of_node = of_node_get(to_of_node(fwnode));
        slave->bus = bus;
        slave->status = SDW_SLAVE_UNATTACHED;
        slave->dev_num = 0;

        mutex_lock(&bus->bus_lock);
        list_add_tail(&slave->node, &bus->slaves);
        mutex_unlock(&bus->bus_lock);

        ret = device_register(&slave->dev);
        if (ret) {
                dev_err(bus->dev, "Failed to add slave: ret %d\n", ret);

                /*
                 * On err, don't free but drop ref as this will be freed
                 * when release method is invoked.
                 */
                mutex_lock(&bus->bus_lock);
                list_del(&slave->node);
                mutex_unlock(&bus->bus_lock);
                put_device(&slave->dev);
        }
        sdw_slave_debugfs_init(slave);

        return ret;
}

#if IS_ENABLED(CONFIG_ACPI)

static bool find_slave(struct sdw_bus *bus,
                       struct acpi_device *adev,
                       struct sdw_slave_id *id)
{
        unsigned long long addr;
        unsigned int link_id;
        acpi_status status;

        status = acpi_evaluate_integer(adev->handle,
                                       METHOD_NAME__ADR, NULL, &addr);

        if (ACPI_FAILURE(status)) {
                dev_err(bus->dev, "_ADR resolution failed: %x\n",
                        status);
                return false;
        }

        /* Extract link id from ADR, Bit 51 to 48 (included) */
        link_id = (addr >> 48) & GENMASK(3, 0);

        /* Check for link_id match */
        if (link_id != bus->link_id)
                return false;

        sdw_extract_slave_id(bus, addr, id);

        return true;
}

/*
 * sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node
 * @bus: SDW bus instance
 *
 * Scans Master ACPI node for SDW child Slave devices and registers it.
 */
int sdw_acpi_find_slaves(struct sdw_bus *bus)
{
        struct acpi_device *adev, *parent;
        struct acpi_device *adev2, *parent2;

        parent = ACPI_COMPANION(bus->dev);
        if (!parent) {
                dev_err(bus->dev, "Can't find parent for acpi bind\n");
                return -ENODEV;
        }

        list_for_each_entry(adev, &parent->children, node) {
                struct sdw_slave_id id;
                struct sdw_slave_id id2;
                bool ignore_unique_id = true;

                if (!find_slave(bus, adev, &id))
                        continue;

                /* brute-force O(N^2) search for duplicates */
                parent2 = parent;
                list_for_each_entry(adev2, &parent2->children, node) {

                        if (adev == adev2)
                                continue;

                        if (!find_slave(bus, adev2, &id2))
                                continue;

                        if (id.sdw_version != id2.sdw_version ||
                            id.mfg_id != id2.mfg_id ||
                            id.part_id != id2.part_id ||
                            id.class_id != id2.class_id)
                                continue;

                        if (id.unique_id != id2.unique_id) {
                                dev_dbg(bus->dev,
                                        "Valid unique IDs %x %x for Slave mfg %x part %d\n",
                                        id.unique_id, id2.unique_id,
                                        id.mfg_id, id.part_id);
                                ignore_unique_id = false;
                        } else {
                                dev_err(bus->dev,
                                        "Invalid unique IDs %x %x for Slave mfg %x part %d\n",
                                        id.unique_id, id2.unique_id,
                                        id.mfg_id, id.part_id);
                                return -ENODEV;
                        }
                }

                if (ignore_unique_id)
                        id.unique_id = SDW_IGNORED_UNIQUE_ID;

                /*
                 * don't error check for sdw_slave_add as we want to continue
                 * adding Slaves
                 */
                sdw_slave_add(bus, &id, acpi_fwnode_handle(adev));
        }

        return 0;
}

#endif

/*
 * sdw_of_find_slaves() - Find Slave devices in master device tree node
 * @bus: SDW bus instance
 *
 * Scans Master DT node for SDW child Slave devices and registers it.
 */
int sdw_of_find_slaves(struct sdw_bus *bus)
{
        struct device *dev = bus->dev;
        struct device_node *node;

        for_each_child_of_node(bus->dev->of_node, node) {
                int link_id, ret, len;
                unsigned int sdw_version;
                const char *compat = NULL;
                struct sdw_slave_id id;
                const __be32 *addr;

                compat = of_get_property(node, "compatible", NULL);
                if (!compat)
                        continue;

                ret = sscanf(compat, "sdw%01x%04hx%04hx%02hhx", &sdw_version,
                             &id.mfg_id, &id.part_id, &id.class_id);

                if (ret != 4) {
                        dev_err(dev, "Invalid compatible string found %s\n",
                                compat);
                        continue;
                }

                addr = of_get_property(node, "reg", &len);
                if (!addr || (len < 2 * sizeof(u32))) {
                        dev_err(dev, "Invalid Link and Instance ID\n");
                        continue;
                }

                link_id = be32_to_cpup(addr++);
                id.unique_id = be32_to_cpup(addr);
                id.sdw_version = sdw_version;

                /* Check for link_id match */
                if (link_id != bus->link_id)
                        continue;

                sdw_slave_add(bus, &id, of_fwnode_handle(node));
        }

        return 0;
}