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/*
* mesh.h: definitions for the driver for the MESH SCSI bus adaptor
* (Macintosh Enhanced SCSI Hardware) found on Power Macintosh computers.
*
* Copyright (C) 1996 Paul Mackerras.
*/
#ifndef _MESH_H
#define _MESH_H
/*
* Registers in the MESH controller.
*/
struct mesh_regs {
unsigned char count_lo;
char pad0[15];
unsigned char count_hi;
char pad1[15];
unsigned char fifo;
char pad2[15];
unsigned char sequence;
char pad3[15];
unsigned char bus_status0;
char pad4[15];
unsigned char bus_status1;
char pad5[15];
unsigned char fifo_count;
char pad6[15];
unsigned char exception;
char pad7[15];
unsigned char error;
char pad8[15];
unsigned char intr_mask;
char pad9[15];
unsigned char interrupt;
char pad10[15];
unsigned char source_id;
char pad11[15];
unsigned char dest_id;
char pad12[15];
unsigned char sync_params;
char pad13[15];
unsigned char mesh_id;
char pad14[15];
unsigned char sel_timeout;
char pad15[15];
};
/* Bits in the sequence register. */
#define SEQ_DMA_MODE 0x80 /* use DMA for data transfer */
#define SEQ_TARGET 0x40 /* put the controller into target mode */
#define SEQ_ATN 0x20 /* assert ATN signal */
#define SEQ_ACTIVE_NEG 0x10 /* use active negation on REQ/ACK */
#define SEQ_CMD 0x0f /* command bits: */
#define SEQ_ARBITRATE 1 /* get the bus */
#define SEQ_SELECT 2 /* select a target */
#define SEQ_COMMAND 3 /* send a command */
#define SEQ_STATUS 4 /* receive status */
#define SEQ_DATAOUT 5 /* send data */
#define SEQ_DATAIN 6 /* receive data */
#define SEQ_MSGOUT 7 /* send a message */
#define SEQ_MSGIN 8 /* receive a message */
#define SEQ_BUSFREE 9 /* look for bus free */
#define SEQ_ENBPARITY 0x0a /* enable parity checking */
#define SEQ_DISPARITY 0x0b /* disable parity checking */
#define SEQ_ENBRESEL 0x0c /* enable reselection */
#define SEQ_DISRESEL 0x0d /* disable reselection */
#define SEQ_RESETMESH 0x0e /* reset the controller */
#define SEQ_FLUSHFIFO 0x0f /* clear out the FIFO */
/* Bits in the bus_status0 and bus_status1 registers:
these correspond directly to the SCSI bus control signals. */
#define BS0_REQ 0x20
#define BS0_ACK 0x10
#define BS0_ATN 0x08
#define BS0_MSG 0x04
#define BS0_CD 0x02
#define BS0_IO 0x01
#define BS1_RST 0x80
#define BS1_BSY 0x40
#define BS1_SEL 0x20
/* Bus phases defined by the bits in bus_status0 */
#define BS0_PHASE (BS0_MSG+BS0_CD+BS0_IO)
#define BP_DATAOUT 0
#define BP_DATAIN BS0_IO
#define BP_COMMAND BS0_CD
#define BP_STATUS (BS0_CD+BS0_IO)
#define BP_MSGOUT (BS0_MSG+BS0_CD)
#define BP_MSGIN (BS0_MSG+BS0_CD+BS0_IO)
/* Bits in the exception register. */
#define EXC_SELWATN 0x20 /* (as target) we were selected with ATN */
#define EXC_SELECTED 0x10 /* (as target) we were selected w/o ATN */
#define EXC_RESELECTED 0x08 /* (as initiator) we were reselected */
#define EXC_ARBLOST 0x04 /* we lost arbitration */
#define EXC_PHASEMM 0x02 /* SCSI phase mismatch */
#define EXC_SELTO 0x01 /* selection timeout */
/* Bits in the error register */
#define ERR_UNEXPDISC 0x40 /* target unexpectedly disconnected */
#define ERR_SCSIRESET 0x20 /* SCSI bus got reset on us */
#define ERR_SEQERR 0x10 /* we did something the chip didn't like */
#define ERR_PARITY 0x01 /* parity error was detected */
/* Bits in the interrupt and intr_mask registers */
#define INT_ERROR 0x04 /* error interrupt */
#define INT_EXCEPTION 0x02 /* exception interrupt */
#define INT_CMDDONE 0x01 /* command done interrupt */
/* Fields in the sync_params register */
#define SYNC_OFF(x) ((x) >> 4) /* offset field */
#define SYNC_PER(x) ((x) & 0xf) /* period field */
#define SYNC_PARAMS(o, p) (((o) << 4) | (p))
#define ASYNC_PARAMS 2 /* sync_params value for async xfers */
/*
* Assuming a clock frequency of 50MHz:
*
* The transfer period with SYNC_PER(sync_params) == x
* is (x + 2) * 40ns, except that x == 0 gives 100ns.
*
* The units of the sel_timeout register are 10ms.
*/
#endif /* _MESH_H */
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