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Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * mesh.h: definitions for the driver for the MESH SCSI bus adaptor
4 * (Macintosh Enhanced SCSI Hardware) found on Power Macintosh computers.
5 *
6 * Copyright (C) 1996 Paul Mackerras.
7 */
8#ifndef _MESH_H
9#define _MESH_H
10
11/*
12 * Registers in the MESH controller.
13 */
14
15struct mesh_regs {
16 unsigned char count_lo;
17 char pad0[15];
18 unsigned char count_hi;
19 char pad1[15];
20 unsigned char fifo;
21 char pad2[15];
22 unsigned char sequence;
23 char pad3[15];
24 unsigned char bus_status0;
25 char pad4[15];
26 unsigned char bus_status1;
27 char pad5[15];
28 unsigned char fifo_count;
29 char pad6[15];
30 unsigned char exception;
31 char pad7[15];
32 unsigned char error;
33 char pad8[15];
34 unsigned char intr_mask;
35 char pad9[15];
36 unsigned char interrupt;
37 char pad10[15];
38 unsigned char source_id;
39 char pad11[15];
40 unsigned char dest_id;
41 char pad12[15];
42 unsigned char sync_params;
43 char pad13[15];
44 unsigned char mesh_id;
45 char pad14[15];
46 unsigned char sel_timeout;
47 char pad15[15];
48};
49
50/* Bits in the sequence register. */
51#define SEQ_DMA_MODE 0x80 /* use DMA for data transfer */
52#define SEQ_TARGET 0x40 /* put the controller into target mode */
53#define SEQ_ATN 0x20 /* assert ATN signal */
54#define SEQ_ACTIVE_NEG 0x10 /* use active negation on REQ/ACK */
55#define SEQ_CMD 0x0f /* command bits: */
56#define SEQ_ARBITRATE 1 /* get the bus */
57#define SEQ_SELECT 2 /* select a target */
58#define SEQ_COMMAND 3 /* send a command */
59#define SEQ_STATUS 4 /* receive status */
60#define SEQ_DATAOUT 5 /* send data */
61#define SEQ_DATAIN 6 /* receive data */
62#define SEQ_MSGOUT 7 /* send a message */
63#define SEQ_MSGIN 8 /* receive a message */
64#define SEQ_BUSFREE 9 /* look for bus free */
65#define SEQ_ENBPARITY 0x0a /* enable parity checking */
66#define SEQ_DISPARITY 0x0b /* disable parity checking */
67#define SEQ_ENBRESEL 0x0c /* enable reselection */
68#define SEQ_DISRESEL 0x0d /* disable reselection */
69#define SEQ_RESETMESH 0x0e /* reset the controller */
70#define SEQ_FLUSHFIFO 0x0f /* clear out the FIFO */
71
72/* Bits in the bus_status0 and bus_status1 registers:
73 these correspond directly to the SCSI bus control signals. */
74#define BS0_REQ 0x20
75#define BS0_ACK 0x10
76#define BS0_ATN 0x08
77#define BS0_MSG 0x04
78#define BS0_CD 0x02
79#define BS0_IO 0x01
80#define BS1_RST 0x80
81#define BS1_BSY 0x40
82#define BS1_SEL 0x20
83
84/* Bus phases defined by the bits in bus_status0 */
85#define BS0_PHASE (BS0_MSG+BS0_CD+BS0_IO)
86#define BP_DATAOUT 0
87#define BP_DATAIN BS0_IO
88#define BP_COMMAND BS0_CD
89#define BP_STATUS (BS0_CD+BS0_IO)
90#define BP_MSGOUT (BS0_MSG+BS0_CD)
91#define BP_MSGIN (BS0_MSG+BS0_CD+BS0_IO)
92
93/* Bits in the exception register. */
94#define EXC_SELWATN 0x20 /* (as target) we were selected with ATN */
95#define EXC_SELECTED 0x10 /* (as target) we were selected w/o ATN */
96#define EXC_RESELECTED 0x08 /* (as initiator) we were reselected */
97#define EXC_ARBLOST 0x04 /* we lost arbitration */
98#define EXC_PHASEMM 0x02 /* SCSI phase mismatch */
99#define EXC_SELTO 0x01 /* selection timeout */
100
101/* Bits in the error register */
102#define ERR_UNEXPDISC 0x40 /* target unexpectedly disconnected */
103#define ERR_SCSIRESET 0x20 /* SCSI bus got reset on us */
104#define ERR_SEQERR 0x10 /* we did something the chip didn't like */
105#define ERR_PARITY 0x01 /* parity error was detected */
106
107/* Bits in the interrupt and intr_mask registers */
108#define INT_ERROR 0x04 /* error interrupt */
109#define INT_EXCEPTION 0x02 /* exception interrupt */
110#define INT_CMDDONE 0x01 /* command done interrupt */
111
112/* Fields in the sync_params register */
113#define SYNC_OFF(x) ((x) >> 4) /* offset field */
114#define SYNC_PER(x) ((x) & 0xf) /* period field */
115#define SYNC_PARAMS(o, p) (((o) << 4) | (p))
116#define ASYNC_PARAMS 2 /* sync_params value for async xfers */
117
118/*
119 * Assuming a clock frequency of 50MHz:
120 *
121 * The transfer period with SYNC_PER(sync_params) == x
122 * is (x + 2) * 40ns, except that x == 0 gives 100ns.
123 *
124 * The units of the sel_timeout register are 10ms.
125 */
126
127
128#endif /* _MESH_H */