// SPDX-License-Identifier: GPL-2.0
/*
 * driver.c - device id matching, driver model, etc.
 *
 * Copyright 2002 Adam Belay <ambx1@neo.rr.com>
 */

#include <linux/string.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/ctype.h>
#include <linux/slab.h>
#include <linux/pnp.h>
#include "base.h"

static int compare_func(const char *ida, const char *idb)
{
        int i;

        /* we only need to compare the last 4 chars */
        for (i = 3; i < 7; i++) {
                if (ida[i] != 'X' &&
                    idb[i] != 'X' && toupper(ida[i]) != toupper(idb[i]))
                        return 0;
        }
        return 1;
}

int compare_pnp_id(struct pnp_id *pos, const char *id)
{
        if (!pos || !id || (strlen(id) != 7))
                return 0;
        if (memcmp(id, "ANYDEVS", 7) == 0)
                return 1;
        while (pos) {
                if (memcmp(pos->id, id, 3) == 0)
                        if (compare_func(pos->id, id) == 1)
                                return 1;
                pos = pos->next;
        }
        return 0;
}

static const struct pnp_device_id *match_device(const struct pnp_driver *drv,
                                                struct pnp_dev *dev)
{
        const struct pnp_device_id *drv_id = drv->id_table;

        if (!drv_id)
                return NULL;

        while (*drv_id->id) {
                if (compare_pnp_id(dev->id, drv_id->id))
                        return drv_id;
                drv_id++;
        }
        return NULL;
}

int pnp_device_attach(struct pnp_dev *pnp_dev)
{
        mutex_lock(&pnp_lock);
        if (pnp_dev->status != PNP_READY) {
                mutex_unlock(&pnp_lock);
                return -EBUSY;
        }
        pnp_dev->status = PNP_ATTACHED;
        mutex_unlock(&pnp_lock);
        return 0;
}
EXPORT_SYMBOL(pnp_device_attach);

void pnp_device_detach(struct pnp_dev *pnp_dev)
{
        mutex_lock(&pnp_lock);
        if (pnp_dev->status == PNP_ATTACHED)
                pnp_dev->status = PNP_READY;
        mutex_unlock(&pnp_lock);
}
EXPORT_SYMBOL(pnp_device_detach);

static int pnp_device_probe(struct device *dev)
{
        int error;
        struct pnp_driver *pnp_drv;
        struct pnp_dev *pnp_dev;
        const struct pnp_device_id *dev_id = NULL;
        pnp_dev = to_pnp_dev(dev);
        pnp_drv = to_pnp_driver(dev->driver);

        error = pnp_device_attach(pnp_dev);
        if (error < 0)
                return error;

        if (pnp_dev->active == 0) {
                if (!(pnp_drv->flags & PNP_DRIVER_RES_DO_NOT_CHANGE)) {
                        error = pnp_activate_dev(pnp_dev);
                        if (error < 0)
                                return error;
                }
        } else if ((pnp_drv->flags & PNP_DRIVER_RES_DISABLE)
                   == PNP_DRIVER_RES_DISABLE) {
                error = pnp_disable_dev(pnp_dev);
                if (error < 0)
                        return error;
        }
        error = 0;
        if (pnp_drv->probe) {
                dev_id = match_device(pnp_drv, pnp_dev);
                if (dev_id != NULL)
                        error = pnp_drv->probe(pnp_dev, dev_id);
        }
        if (error >= 0) {
                pnp_dev->driver = pnp_drv;
                error = 0;
        } else
                goto fail;

        return error;

fail:
        pnp_device_detach(pnp_dev);
        return error;
}

static void pnp_device_remove(struct device *dev)
{
        struct pnp_dev *pnp_dev = to_pnp_dev(dev);
        struct pnp_driver *drv = pnp_dev->driver;

        if (drv) {
                if (drv->remove)
                        drv->remove(pnp_dev);
                pnp_dev->driver = NULL;
        }

        if (pnp_dev->active &&
            (!drv || !(drv->flags & PNP_DRIVER_RES_DO_NOT_CHANGE)))
                pnp_disable_dev(pnp_dev);

        pnp_device_detach(pnp_dev);
}

static void pnp_device_shutdown(struct device *dev)
{
        struct pnp_dev *pnp_dev = to_pnp_dev(dev);
        struct pnp_driver *drv = pnp_dev->driver;

        if (drv && drv->shutdown)
                drv->shutdown(pnp_dev);
}

static int pnp_uevent(const struct device *dev, struct kobj_uevent_env *env)
{
        struct pnp_id *pos;
        const struct pnp_dev *pnp_dev = to_pnp_dev(dev);

        if (!dev)
                return -ENODEV;

        pos = pnp_dev->id;
        while (pos) {
                if (add_uevent_var(env, "MODALIAS=pnp:d%s", pos->id))
                        return -ENOMEM;
                pos = pos->next;
        }

        return 0;
}

static int pnp_bus_match(struct device *dev, const struct device_driver *drv)
{
        struct pnp_dev *pnp_dev = to_pnp_dev(dev);
        const struct pnp_driver *pnp_drv = to_pnp_driver(drv);

        if (match_device(pnp_drv, pnp_dev) == NULL)
                return 0;
        return 1;
}

static int __pnp_bus_suspend(struct device *dev, pm_message_t state)
{
        struct pnp_dev *pnp_dev = to_pnp_dev(dev);
        struct pnp_driver *pnp_drv = pnp_dev->driver;
        int error;

        if (!pnp_drv)
                return 0;

        if (pnp_drv->driver.pm && pnp_drv->driver.pm->suspend) {
                error = pnp_drv->driver.pm->suspend(dev);
                suspend_report_result(dev, pnp_drv->driver.pm->suspend, error);
                if (error)
                        return error;
        }

        if (pnp_drv->suspend) {
                error = pnp_drv->suspend(pnp_dev, state);
                if (error)
                        return error;
        }

        /* can_write is necessary to be able to re-start the device on resume */
        if (pnp_can_disable(pnp_dev) && pnp_can_write(pnp_dev)) {
                error = pnp_stop_dev(pnp_dev);
                if (error)
                        return error;
        }

        if (pnp_can_suspend(pnp_dev))
                pnp_dev->protocol->suspend(pnp_dev, state);
        return 0;
}

static int pnp_bus_suspend(struct device *dev)
{
        return __pnp_bus_suspend(dev, PMSG_SUSPEND);
}

static int pnp_bus_freeze(struct device *dev)
{
        return __pnp_bus_suspend(dev, PMSG_FREEZE);
}

static int pnp_bus_poweroff(struct device *dev)
{
        return __pnp_bus_suspend(dev, PMSG_HIBERNATE);
}

static int pnp_bus_resume(struct device *dev)
{
        struct pnp_dev *pnp_dev = to_pnp_dev(dev);
        struct pnp_driver *pnp_drv = pnp_dev->driver;
        int error;

        if (!pnp_drv)
                return 0;

        if (pnp_dev->protocol->resume) {
                error = pnp_dev->protocol->resume(pnp_dev);
                if (error)
                        return error;
        }

        if (pnp_can_write(pnp_dev)) {
                error = pnp_start_dev(pnp_dev);
                if (error)
                        return error;
        }

        if (pnp_drv->driver.pm && pnp_drv->driver.pm->resume) {
                error = pnp_drv->driver.pm->resume(dev);
                if (error)
                        return error;
        }

        if (pnp_drv->resume) {
                error = pnp_drv->resume(pnp_dev);
                if (error)
                        return error;
        }

        return 0;
}

static const struct dev_pm_ops pnp_bus_dev_pm_ops = {
        /* Suspend callbacks */
        .suspend = pnp_bus_suspend,
        .resume = pnp_bus_resume,
        /* Hibernate callbacks */
        .freeze = pnp_bus_freeze,
        .thaw = pnp_bus_resume,
        .poweroff = pnp_bus_poweroff,
        .restore = pnp_bus_resume,
};

const struct bus_type pnp_bus_type = {
        .name    = "pnp",
        .match   = pnp_bus_match,
        .uevent  = pnp_uevent,
        .probe   = pnp_device_probe,
        .remove  = pnp_device_remove,
        .shutdown = pnp_device_shutdown,
        .pm      = &pnp_bus_dev_pm_ops,
        .dev_groups = pnp_dev_groups,
};

bool dev_is_pnp(const struct device *dev)
{
        return dev->bus == &pnp_bus_type;
}
EXPORT_SYMBOL_GPL(dev_is_pnp);

int pnp_register_driver(struct pnp_driver *drv)
{
        drv->driver.name = drv->name;
        drv->driver.bus = &pnp_bus_type;

        return driver_register(&drv->driver);
}
EXPORT_SYMBOL(pnp_register_driver);

void pnp_unregister_driver(struct pnp_driver *drv)
{
        driver_unregister(&drv->driver);
}
EXPORT_SYMBOL(pnp_unregister_driver);

/**
 * pnp_add_id - adds an EISA id to the specified device
 * @dev: pointer to the desired device
 * @id: pointer to an EISA id string
 */
struct pnp_id *pnp_add_id(struct pnp_dev *dev, const char *id)
{
        struct pnp_id *dev_id, *ptr;

        dev_id = kzalloc_obj(struct pnp_id);
        if (!dev_id)
                return NULL;

        dev_id->id[0] = id[0];
        dev_id->id[1] = id[1];
        dev_id->id[2] = id[2];
        dev_id->id[3] = tolower(id[3]);
        dev_id->id[4] = tolower(id[4]);
        dev_id->id[5] = tolower(id[5]);
        dev_id->id[6] = tolower(id[6]);
        dev_id->id[7] = '\0';

        dev_id->next = NULL;
        ptr = dev->id;
        while (ptr && ptr->next)
                ptr = ptr->next;
        if (ptr)
                ptr->next = dev_id;
        else
                dev->id = dev_id;

        return dev_id;
}