2 * ide.h 31 Mar 2004 - IDE Interface definitions
4 * Copyright (c) 2004 Nathan Keynes. Distribution and modification permitted
5 * under the terms of the GNU General Public License version 2 or later.
7 * This file defines the interface and structures of the dreamcast's IDE port.
8 * Note that the register definitions are in asic.h, as the registers fall into
9 * the general ASIC ranges (and I don't want to use smaller pages at this
10 * stage). The registers here are exactly as per the ATA specifications, which
11 * makes things a little easier.
18 struct ide_registers {
19 uint8_t status; /* A05F709C + A05F7018 Read-only */
20 uint8_t control; /* A05F7018 Write-only 01110 */
21 uint8_t error; /* A05F7084 Read-only 10001 */
22 uint8_t feature; /* A05F7084 Write-only 10001 */
23 uint8_t count; /* A05F7088 Read/Write 10010 */
24 uint8_t disc; /* A05F708C Read-only 10011 */
25 uint8_t lba0; /* A05F708C Write-only 10011 (NB: Presumed, TBV */
26 uint8_t lba1; /* A05F7090 Read/Write 10100 */
27 uint8_t lba2; /* A05F7094 Read/Write 10101 */
28 uint8_t device; /* A05F7098 Read/Write 10110 */
29 uint8_t command; /* A05F709C Write-only 10111 */
31 /* We don't keep the data register per se, rather the currently pending
32 * data is kept here and read out a byte at a time (in PIO mode) or all at
33 * once (in DMA mode). The IDE routines are responsible for managing this
34 * memory. If dataptr == NULL, there is no data available.
37 uint16_t *readptr, *writeptr;
41 #define IDE_ST_BUSY 0x80
42 #define IDE_ST_READY 0x40
43 #define IDE_ST_SERV 0x10
44 #define IDE_ST_DATA 0x08
45 #define IDE_ST_ERROR 0x01
47 #define IDE_CTL_RESET 0x04
48 #define IDE_CTL_IRQEN 0x02 /* IRQ enabled when == 0 */
50 #define IDE_CMD_RESET_DEVICE 0x08
51 #define IDE_CMD_PACKET 0xA0
52 #define IDE_CMD_IDENTIFY_PACKET_DEVICE 0xA1
53 #define IDE_CMD_SERVICE 0xA2
54 #define IDE_CMD_SET_FEATURE 0xEF
56 /* The disc register indicates the current contents of the drive. When open
59 #define IDE_DISC_AUDIO 0x00
60 #define IDE_DISC_NONE 0x06
61 #define IDE_DISC_CDROM 0x20
62 #define IDE_DISC_GDROM 0x80
63 #define IDE_DISC_READY 0x01 /* ored with above */
64 #define IDE_DISC_IDLE 0x02 /* ie spun-down */
66 #define PKT_CMD_RESET 0x00 /* Wild-ass guess */
67 #define PKT_CMD_IDENTIFY 0x11
69 extern struct ide_registers idereg;
71 /* Note: control can be written at any time - all other registers are writable
72 * only when ide_can_write_regs() is true
74 #define ide_can_write_regs() ((idereg.status&0x88)==0)
77 * a) Writing the command register
78 * b) Reading the status (but not altstatus) register
79 * (whether this actually has any effect an the ASIC event is TBD)
81 void ide_clear_interrupt(void);
85 uint16_t ide_read_data_pio(void);
86 void ide_write_data_pio( uint16_t value );
87 void ide_write_buffer( char * );
89 void ide_write_command( uint8_t command );
90 void ide_write_control( uint8_t value );
.
lxdream 0.9.1