/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * Copyright © 2003-2010 David Woodhouse <dwmw2@infradead.org>
 */

#ifndef __MTD_TRANS_H__
#define __MTD_TRANS_H__

#include <linux/mutex.h>
#include <linux/kref.h>
#include <linux/sysfs.h>

struct hd_geometry;
struct mtd_info;
struct mtd_blktrans_ops;
struct file;
struct inode;

struct mtd_blktrans_dev {
        struct mtd_blktrans_ops *tr;
        struct list_head list;
        struct mtd_info *mtd;
        struct mutex lock;
        int devnum;
        bool bg_stop;
        unsigned long size;
        int readonly;
        int open;
        struct kref ref;
        struct gendisk *disk;
        struct attribute_group *disk_attributes;
        struct request_queue *rq;
        struct list_head rq_list;
        struct blk_mq_tag_set *tag_set;
        spinlock_t queue_lock;
        void *priv;
        bool writable;
};

struct mtd_blktrans_ops {
        char *name;
        int major;
        int part_bits;
        int blksize;
        int blkshift;

        /* Access functions */
        int (*readsect)(struct mtd_blktrans_dev *dev,
                    unsigned long block, char *buffer);
        int (*writesect)(struct mtd_blktrans_dev *dev,
                     unsigned long block, char *buffer);
        int (*discard)(struct mtd_blktrans_dev *dev,
                       unsigned long block, unsigned nr_blocks);
        void (*background)(struct mtd_blktrans_dev *dev);

        /* Block layer ioctls */
        int (*getgeo)(struct mtd_blktrans_dev *dev, struct hd_geometry *geo);
        int (*flush)(struct mtd_blktrans_dev *dev);

        /* Called with mtd_table_mutex held; no race with add/remove */
        int (*open)(struct mtd_blktrans_dev *dev);
        void (*release)(struct mtd_blktrans_dev *dev);

        /* Called on {de,}registration and on subsequent addition/removal
           of devices, with mtd_table_mutex held. */
        void (*add_mtd)(struct mtd_blktrans_ops *tr, struct mtd_info *mtd);
        void (*remove_dev)(struct mtd_blktrans_dev *dev);

        struct list_head devs;
        struct list_head list;
        struct module *owner;
};

extern int register_mtd_blktrans(struct mtd_blktrans_ops *tr);
extern int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr);
extern int add_mtd_blktrans_dev(struct mtd_blktrans_dev *dev);
extern int del_mtd_blktrans_dev(struct mtd_blktrans_dev *dev);
extern int mtd_blktrans_cease_background(struct mtd_blktrans_dev *dev);

/**
 * module_mtd_blktrans() - Helper macro for registering a mtd blktrans driver
 * @__mtd_blktrans: mtd_blktrans_ops struct
 *
 * Helper macro for mtd blktrans drivers which do not do anything special in
 * module init/exit. This eliminates a lot of boilerplate. Each module may only
 * use this macro once, and calling it replaces module_init() and module_exit()
 */
#define module_mtd_blktrans(__mtd_blktrans) \
        module_driver(__mtd_blktrans, register_mtd_blktrans, \
                                        deregister_mtd_blktrans)

#endif /* __MTD_TRANS_H__ */