/*
 * CHU - driver for CH375 in disk mode
 * Copyright (C) 2024 Javier S. Pedro
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.

 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

#ifndef CHUDISK_H
#define CHUDISK_H

#include <stdbool.h>

#include "inc/dosdrv.h"

#define MAX_UNITS 4

#define SECTOR_SIZE 512

// Configuration values shared between driver init code and resident code
/* Used by ch375.h, too. */
extern unsigned short ch375_port;

extern unsigned char num_units;

extern bool read_only;

extern bool show_fat32;

extern struct chudisk_data
{
	/** Pointers to all BPBs, to return to DOS during init. */
	DOS_BPB * bpb_ptrs[MAX_UNITS];

	/** Whether we are ready to handle IO, i.e. disk init, partitions scanned. */
	bool ready;

	uint32_t sectors;
	uint32_t bytesPerSector;

	struct chudisk_unit {
		/** Whether the partition exists (start_sector points to it) */
		bool exists;
		/** Note in theory may be zero (superfloppy) */
		uint32_t start_sector;
		/** Number of sectors for this partition. */
		uint32_t sectors;
		/** Whether the partition's BPB was loaded. */
		bool ready;
		/** DOS device params (contains BPB), only valid if 'ready'. */
		DOS_BPB bpb;
	} unit[MAX_UNITS];
} data;

// Functions called by both init part and resident part
extern void driver_init(DOS_DRS __far *drs);

extern char resident_end;

extern uint8_t wait_for_ch375_result(unsigned int max_ticks);


// CHUDISK IOCTLs
// These are used with the DISK major
// TODO Not sure we can really happily add custom minors here,
// but then again DOS outright refuses to accept any other major
enum CHUDISK_IOCTL_DISK_MINOR {
	CHUDISK_IOCTL_DISK_READ_ABS_SECTOR = 0xC1
};

typedef _Packed union CHUDISK_IOCTL_DISK_DATA
{
	struct CHUDISK_RWABSSECTOR {
	    uint32_t sector;
	    uint8_t sectors;
	    void far * buffer;
	} rwabs;
} CHUDISK_IOCTL_DISK_DATA;

#endif // CHUDISK_H