/**
 * @file ide.h
 * @brief IDE/ATA disk driver.
 *
 * Enumerates IDE devices on the primary and secondary channels, identifies
 * ATA hard drives and ATAPI CD-ROMs, and registers them with the devicefs
 * subsystem as block devices (hddN / cdN).
 */

#ifndef IDE_H
#define IDE_H

#include <stdint.h>

/** Maximum number of IDE devices (2 channels × 2 drives). */
#define IDE_MAX_DEVICES 4

/** IDE channel I/O port bases. */
#define IDE_PRIMARY_IO     0x1F0
#define IDE_PRIMARY_CTRL   0x3F6
#define IDE_SECONDARY_IO   0x170
#define IDE_SECONDARY_CTRL 0x376

/** IDE register offsets from I/O base. */
#define IDE_REG_DATA       0x00
#define IDE_REG_ERROR      0x01
#define IDE_REG_FEATURES   0x01
#define IDE_REG_SECCOUNT   0x02
#define IDE_REG_LBA_LO     0x03
#define IDE_REG_LBA_MID    0x04
#define IDE_REG_LBA_HI     0x05
#define IDE_REG_DRIVE_HEAD 0x06
#define IDE_REG_STATUS     0x07
#define IDE_REG_COMMAND    0x07

/** IDE status register bits. */
#define IDE_STATUS_ERR   0x01  /**< Error occurred. */
#define IDE_STATUS_DRQ   0x08  /**< Data request ready. */
#define IDE_STATUS_SRV   0x10  /**< Overlapped mode service request. */
#define IDE_STATUS_DF    0x20  /**< Drive fault. */
#define IDE_STATUS_DRDY  0x40  /**< Drive ready. */
#define IDE_STATUS_BSY   0x80  /**< Drive busy. */

/** IDE commands. */
#define IDE_CMD_IDENTIFY     0xEC  /**< ATA IDENTIFY DEVICE. */
#define IDE_CMD_IDENTIFY_PKT 0xA1  /**< ATAPI IDENTIFY PACKET DEVICE. */
#define IDE_CMD_READ_PIO     0x20  /**< Read sectors (PIO, 28-bit LBA). */
#define IDE_CMD_WRITE_PIO    0x30  /**< Write sectors (PIO, 28-bit LBA). */

/** IDE device types. */
#define IDE_TYPE_NONE  0  /**< No device present. */
#define IDE_TYPE_ATA   1  /**< ATA hard disk. */
#define IDE_TYPE_ATAPI 2  /**< ATAPI CD/DVD drive. */

/**
 * IDE device descriptor.
 */
typedef struct ide_device {
    uint8_t present;            /**< 1 if device is present. */
    uint8_t type;               /**< IDE_TYPE_ATA or IDE_TYPE_ATAPI. */
    uint8_t channel;            /**< 0 = primary, 1 = secondary. */
    uint8_t drive;              /**< 0 = master, 1 = slave. */
    uint16_t io_base;           /**< I/O base port for this channel. */
    uint16_t ctrl_base;         /**< Control port for this channel. */
    uint32_t sector_count;      /**< Total sectors (28-bit LBA max). */
    uint32_t sector_size;       /**< Sector size in bytes (usually 512). */
    char model[41];             /**< Model string from IDENTIFY. */
} ide_device_t;

/**
 * Initialize the IDE driver.
 *
 * Scans primary and secondary channels for ATA/ATAPI devices,
 * reads their IDENTIFY data, and registers them with devicefs.
 *
 * @return Number of devices found.
 */
int ide_init(void);

/**
 * Get an IDE device by index (0–3).
 *
 * @param index Device index.
 * @return Pointer to the device descriptor, or NULL if invalid/not present.
 */
ide_device_t *ide_get_device(int index);

#endif /* IDE_H */