/**

  * $Id: ide.h,v 1.2 2005-12-25 08:24:11 nkeynes Exp $

  *

  * This file defines the interface and structures of the dreamcast's IDE 

  * port. Note that the register definitions are in asic.h, as the registers

  * fall into the general ASIC ranges (and I don't want to use smaller pages

  * at this stage). The registers here are exactly as per the ATA 

  * specifications, which makes things a little easier.

  *

  * Copyright (c) 2005 Nathan Keynes.

  *

  * 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 2 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.

  */

 #ifndef dream_ide_H

 #define dream_ide_H 1

 #include "dream.h"

 struct ide_registers {

     uint8_t status;  /* A05F709C + A05F7018 Read-only */

     uint8_t control; /* A05F7018 Write-only 01110 */

     uint8_t error;   /* A05F7084 Read-only  10001 */

     uint8_t feature; /* A05F7084 Write-only 10001 */

     uint8_t count;   /* A05F7088 Read/Write 10010 */

     uint8_t disc;    /* A05F708C Read-only 10011 */

     uint8_t lba0;    /* A05F708C Write-only 10011 (NB: Presumed, TBV */

     uint8_t lba1;    /* A05F7090 Read/Write 10100 */

     uint8_t lba2;    /* A05F7094 Read/Write 10101 */

     uint8_t device;  /* A05F7098 Read/Write 10110 */

     uint8_t command; /* A05F709C Write-only 10111 */

     /* We don't keep the data register per se, rather the currently pending

      * data is kept here and read out a byte at a time (in PIO mode) or all at

      * once (in DMA mode). The IDE routines are responsible for managing this

      * memory. If dataptr == NULL, there is no data available.

      */

     char *data;

     uint16_t *readptr, *writeptr;

     int datalen;

 };

 #define IDE_ST_BUSY  0x80

 #define IDE_ST_READY 0x40

 #define IDE_ST_SERV  0x10

 #define IDE_ST_DATA  0x08

 #define IDE_ST_ERROR 0x01

 #define IDE_CTL_RESET 0x04

 #define IDE_CTL_IRQEN 0x02 /* IRQ enabled when == 0 */

 #define IDE_CMD_RESET_DEVICE 0x08

 #define IDE_CMD_PACKET 0xA0

 #define IDE_CMD_IDENTIFY_PACKET_DEVICE 0xA1

 #define IDE_CMD_SERVICE 0xA2

 #define IDE_CMD_SET_FEATURE 0xEF

 /* The disc register indicates the current contents of the drive. When open

  * contains 0x06.

  */

 #define IDE_DISC_AUDIO 0x00

 #define IDE_DISC_NONE  0x06

 #define IDE_DISC_CDROM 0x20

 #define IDE_DISC_GDROM 0x80

 #define IDE_DISC_READY 0x01 /* ored with above */

 #define IDE_DISC_IDLE  0x02 /* ie spun-down */

 #define PKT_CMD_RESET    0x00 /* Wild-ass guess */

 #define PKT_CMD_IDENTIFY 0x11

 extern struct ide_registers idereg;

 /* Note: control can be written at any time - all other registers are writable

  * only when ide_can_write_regs() is true

  */

 #define ide_can_write_regs() ((idereg.status&0x88)==0)

 /* Called upon:

  *   a) Writing the command register

  *   b) Reading the status (but not altstatus) register

  *  (whether this actually has any effect an the ASIC event is TBD)

  */

 void ide_clear_interrupt(void);

 void ide_reset(void);

 uint16_t ide_read_data_pio(void);

 void ide_write_data_pio( uint16_t value );

 void ide_write_buffer( char * ); 

 void ide_write_command( uint8_t command );

 void ide_write_control( uint8_t value );

 #endif