// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * RapidIO driver support
 *
 * Copyright 2005 MontaVista Software, Inc.
 * Matt Porter <mporter@kernel.crashing.org>
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/rio.h>
#include <linux/rio_ids.h>

#include "rio.h"

/**
 *  rio_match_device - Tell if a RIO device has a matching RIO device id structure
 *  @id: the RIO device id structure to match against
 *  @rdev: the RIO device structure to match against
 *
 *  Used from driver probe and bus matching to check whether a RIO device
 *  matches a device id structure provided by a RIO driver. Returns the
 *  matching &struct rio_device_id or %NULL if there is no match.
 */
static const struct rio_device_id *rio_match_device(const struct rio_device_id
                                                    *id,
                                                    const struct rio_dev *rdev)
{
        while (id->vid || id->asm_vid) {
                if (((id->vid == RIO_ANY_ID) || (id->vid == rdev->vid)) &&
                    ((id->did == RIO_ANY_ID) || (id->did == rdev->did)) &&
                    ((id->asm_vid == RIO_ANY_ID)
                     || (id->asm_vid == rdev->asm_vid))
                    && ((id->asm_did == RIO_ANY_ID)
                        || (id->asm_did == rdev->asm_did)))
                        return id;
                id++;
        }
        return NULL;
}

/**
 * rio_dev_get - Increments the reference count of the RIO device structure
 *
 * @rdev: RIO device being referenced
 *
 * Each live reference to a device should be refcounted.
 *
 * Drivers for RIO devices should normally record such references in
 * their probe() methods, when they bind to a device, and release
 * them by calling rio_dev_put(), in their disconnect() methods.
 */
struct rio_dev *rio_dev_get(struct rio_dev *rdev)
{
        if (rdev)
                get_device(&rdev->dev);

        return rdev;
}

/**
 * rio_dev_put - Release a use of the RIO device structure
 *
 * @rdev: RIO device being disconnected
 *
 * Must be called when a user of a device is finished with it.
 * When the last user of the device calls this function, the
 * memory of the device is freed.
 */
void rio_dev_put(struct rio_dev *rdev)
{
        if (rdev)
                put_device(&rdev->dev);
}

/**
 *  rio_device_probe - Tell if a RIO device structure has a matching RIO device id structure
 *  @dev: the RIO device structure to match against
 *
 * return 0 and set rio_dev->driver when drv claims rio_dev, else error
 */
static int rio_device_probe(struct device *dev)
{
        struct rio_driver *rdrv = to_rio_driver(dev->driver);
        struct rio_dev *rdev = to_rio_dev(dev);
        int error = -ENODEV;
        const struct rio_device_id *id;

        if (!rdev->driver && rdrv->probe) {
                if (!rdrv->id_table)
                        return error;
                id = rio_match_device(rdrv->id_table, rdev);
                rio_dev_get(rdev);
                if (id)
                        error = rdrv->probe(rdev, id);
                if (error >= 0) {
                        rdev->driver = rdrv;
                        error = 0;
                } else
                        rio_dev_put(rdev);
        }
        return error;
}

/**
 *  rio_device_remove - Remove a RIO device from the system
 *
 *  @dev: the RIO device structure to match against
 *
 * Remove a RIO device from the system. If it has an associated
 * driver, then run the driver remove() method.  Then update
 * the reference count.
 */
static int rio_device_remove(struct device *dev)
{
        struct rio_dev *rdev = to_rio_dev(dev);
        struct rio_driver *rdrv = rdev->driver;

        if (rdrv) {
                if (rdrv->remove)
                        rdrv->remove(rdev);
                rdev->driver = NULL;
        }

        rio_dev_put(rdev);

        return 0;
}

static void rio_device_shutdown(struct device *dev)
{
        struct rio_dev *rdev = to_rio_dev(dev);
        struct rio_driver *rdrv = rdev->driver;

        dev_dbg(dev, "RIO: %s\n", __func__);

        if (rdrv && rdrv->shutdown)
                rdrv->shutdown(rdev);
}

/**
 *  rio_register_driver - register a new RIO driver
 *  @rdrv: the RIO driver structure to register
 *
 *  Adds a &struct rio_driver to the list of registered drivers.
 *  Returns a negative value on error, otherwise 0. If no error
 *  occurred, the driver remains registered even if no device
 *  was claimed during registration.
 */
int rio_register_driver(struct rio_driver *rdrv)
{
        /* initialize common driver fields */
        rdrv->driver.name = rdrv->name;
        rdrv->driver.bus = &rio_bus_type;

        /* register with core */
        return driver_register(&rdrv->driver);
}

/**
 *  rio_unregister_driver - unregister a RIO driver
 *  @rdrv: the RIO driver structure to unregister
 *
 *  Deletes the &struct rio_driver from the list of registered RIO
 *  drivers, gives it a chance to clean up by calling its remove()
 *  function for each device it was responsible for, and marks those
 *  devices as driverless.
 */
void rio_unregister_driver(struct rio_driver *rdrv)
{
        driver_unregister(&rdrv->driver);
}

void rio_attach_device(struct rio_dev *rdev)
{
        rdev->dev.bus = &rio_bus_type;
}
EXPORT_SYMBOL_GPL(rio_attach_device);

/**
 *  rio_match_bus - Tell if a RIO device structure has a matching RIO driver device id structure
 *  @dev: the standard device structure to match against
 *  @drv: the standard driver structure containing the ids to match against
 *
 *  Used by a driver to check whether a RIO device present in the
 *  system is in its list of supported devices. Returns 1 if
 *  there is a matching &struct rio_device_id or 0 if there is
 *  no match.
 */
static int rio_match_bus(struct device *dev, struct device_driver *drv)
{
        struct rio_dev *rdev = to_rio_dev(dev);
        struct rio_driver *rdrv = to_rio_driver(drv);
        const struct rio_device_id *id = rdrv->id_table;
        const struct rio_device_id *found_id;

        if (!id)
                goto out;

        found_id = rio_match_device(id, rdev);

        if (found_id)
                return 1;

      out:return 0;
}

static int rio_uevent(struct device *dev, struct kobj_uevent_env *env)
{
        struct rio_dev *rdev;

        if (!dev)
                return -ENODEV;

        rdev = to_rio_dev(dev);
        if (!rdev)
                return -ENODEV;

        if (add_uevent_var(env, "MODALIAS=rapidio:v%04Xd%04Xav%04Xad%04X",
                           rdev->vid, rdev->did, rdev->asm_vid, rdev->asm_did))
                return -ENOMEM;
        return 0;
}

struct class rio_mport_class = {
        .name           = "rapidio_port",
        .owner          = THIS_MODULE,
        .dev_groups     = rio_mport_groups,
};
EXPORT_SYMBOL_GPL(rio_mport_class);

struct bus_type rio_bus_type = {
        .name = "rapidio",
        .match = rio_match_bus,
        .dev_groups = rio_dev_groups,
        .bus_groups = rio_bus_groups,
        .probe = rio_device_probe,
        .remove = rio_device_remove,
        .shutdown = rio_device_shutdown,
        .uevent = rio_uevent,
};

/**
 *  rio_bus_init - Register the RapidIO bus with the device model
 *
 *  Registers the RIO mport device class and RIO bus type with the Linux
 *  device model.
 */
static int __init rio_bus_init(void)
{
        int ret;

        ret = class_register(&rio_mport_class);
        if (!ret) {
                ret = bus_register(&rio_bus_type);
                if (ret)
                        class_unregister(&rio_mport_class);
        }
        return ret;
}

postcore_initcall(rio_bus_init);

EXPORT_SYMBOL_GPL(rio_register_driver);
EXPORT_SYMBOL_GPL(rio_unregister_driver);
EXPORT_SYMBOL_GPL(rio_bus_type);
EXPORT_SYMBOL_GPL(rio_dev_get);
EXPORT_SYMBOL_GPL(rio_dev_put);