// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright(c) 2007 - 2009 Intel Corporation. All rights reserved.
 */

#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/device.h>
#include <linux/idr.h>
#include <linux/kdev_t.h>
#include <linux/err.h>
#include <linux/dca.h>
#include <linux/gfp.h>
#include <linux/export.h>

static const struct class dca_class = {
        .name = "dca",
};
static struct idr dca_idr;
static spinlock_t dca_idr_lock;

int dca_sysfs_add_req(struct dca_provider *dca, struct device *dev, int slot)
{
        struct device *cd;
        static int req_count;

        cd = device_create(&dca_class, dca->cd, MKDEV(0, slot + 1), NULL,
                           "requester%d", req_count++);
        return PTR_ERR_OR_ZERO(cd);
}

void dca_sysfs_remove_req(struct dca_provider *dca, int slot)
{
        device_destroy(&dca_class, MKDEV(0, slot + 1));
}

int dca_sysfs_add_provider(struct dca_provider *dca, struct device *dev)
{
        struct device *cd;
        int ret;

        idr_preload(GFP_KERNEL);
        spin_lock(&dca_idr_lock);

        ret = idr_alloc(&dca_idr, dca, 0, 0, GFP_NOWAIT);
        if (ret >= 0)
                dca->id = ret;

        spin_unlock(&dca_idr_lock);
        idr_preload_end();
        if (ret < 0)
                return ret;

        cd = device_create(&dca_class, dev, MKDEV(0, 0), NULL, "dca%d", dca->id);
        if (IS_ERR(cd)) {
                spin_lock(&dca_idr_lock);
                idr_remove(&dca_idr, dca->id);
                spin_unlock(&dca_idr_lock);
                return PTR_ERR(cd);
        }
        dca->cd = cd;
        return 0;
}

void dca_sysfs_remove_provider(struct dca_provider *dca)
{
        device_unregister(dca->cd);
        dca->cd = NULL;
        spin_lock(&dca_idr_lock);
        idr_remove(&dca_idr, dca->id);
        spin_unlock(&dca_idr_lock);
}

int __init dca_sysfs_init(void)
{
        int err;

        idr_init(&dca_idr);
        spin_lock_init(&dca_idr_lock);

        err = class_register(&dca_class);
        if (err) {
                idr_destroy(&dca_idr);
                return err;
        }
        return 0;
}

void __exit dca_sysfs_exit(void)
{
        class_unregister(&dca_class);
        idr_destroy(&dca_idr);
}