1 /* SPDX-License-Identifier: GPL-2.0 */
3 * mesh.h: definitions for the driver for the MESH SCSI bus adaptor
4 * (Macintosh Enhanced SCSI Hardware) found on Power Macintosh computers.
6 * Copyright (C) 1996 Paul Mackerras.
11 struct mesh_cmd_priv {
17 static inline struct mesh_cmd_priv *mesh_priv(struct scsi_cmnd *cmd)
19 return scsi_cmd_priv(cmd);
23 * Registers in the MESH controller.
27 unsigned char count_lo;
29 unsigned char count_hi;
33 unsigned char sequence;
35 unsigned char bus_status0;
37 unsigned char bus_status1;
39 unsigned char fifo_count;
41 unsigned char exception;
45 unsigned char intr_mask;
47 unsigned char interrupt;
49 unsigned char source_id;
51 unsigned char dest_id;
53 unsigned char sync_params;
55 unsigned char mesh_id;
57 unsigned char sel_timeout;
61 /* Bits in the sequence register. */
62 #define SEQ_DMA_MODE 0x80 /* use DMA for data transfer */
63 #define SEQ_TARGET 0x40 /* put the controller into target mode */
64 #define SEQ_ATN 0x20 /* assert ATN signal */
65 #define SEQ_ACTIVE_NEG 0x10 /* use active negation on REQ/ACK */
66 #define SEQ_CMD 0x0f /* command bits: */
67 #define SEQ_ARBITRATE 1 /* get the bus */
68 #define SEQ_SELECT 2 /* select a target */
69 #define SEQ_COMMAND 3 /* send a command */
70 #define SEQ_STATUS 4 /* receive status */
71 #define SEQ_DATAOUT 5 /* send data */
72 #define SEQ_DATAIN 6 /* receive data */
73 #define SEQ_MSGOUT 7 /* send a message */
74 #define SEQ_MSGIN 8 /* receive a message */
75 #define SEQ_BUSFREE 9 /* look for bus free */
76 #define SEQ_ENBPARITY 0x0a /* enable parity checking */
77 #define SEQ_DISPARITY 0x0b /* disable parity checking */
78 #define SEQ_ENBRESEL 0x0c /* enable reselection */
79 #define SEQ_DISRESEL 0x0d /* disable reselection */
80 #define SEQ_RESETMESH 0x0e /* reset the controller */
81 #define SEQ_FLUSHFIFO 0x0f /* clear out the FIFO */
83 /* Bits in the bus_status0 and bus_status1 registers:
84 these correspond directly to the SCSI bus control signals. */
95 /* Bus phases defined by the bits in bus_status0 */
96 #define BS0_PHASE (BS0_MSG+BS0_CD+BS0_IO)
98 #define BP_DATAIN BS0_IO
99 #define BP_COMMAND BS0_CD
100 #define BP_STATUS (BS0_CD+BS0_IO)
101 #define BP_MSGOUT (BS0_MSG+BS0_CD)
102 #define BP_MSGIN (BS0_MSG+BS0_CD+BS0_IO)
104 /* Bits in the exception register. */
105 #define EXC_SELWATN 0x20 /* (as target) we were selected with ATN */
106 #define EXC_SELECTED 0x10 /* (as target) we were selected w/o ATN */
107 #define EXC_RESELECTED 0x08 /* (as initiator) we were reselected */
108 #define EXC_ARBLOST 0x04 /* we lost arbitration */
109 #define EXC_PHASEMM 0x02 /* SCSI phase mismatch */
110 #define EXC_SELTO 0x01 /* selection timeout */
112 /* Bits in the error register */
113 #define ERR_UNEXPDISC 0x40 /* target unexpectedly disconnected */
114 #define ERR_SCSIRESET 0x20 /* SCSI bus got reset on us */
115 #define ERR_SEQERR 0x10 /* we did something the chip didn't like */
116 #define ERR_PARITY 0x01 /* parity error was detected */
118 /* Bits in the interrupt and intr_mask registers */
119 #define INT_ERROR 0x04 /* error interrupt */
120 #define INT_EXCEPTION 0x02 /* exception interrupt */
121 #define INT_CMDDONE 0x01 /* command done interrupt */
123 /* Fields in the sync_params register */
124 #define SYNC_OFF(x) ((x) >> 4) /* offset field */
125 #define SYNC_PER(x) ((x) & 0xf) /* period field */
126 #define SYNC_PARAMS(o, p) (((o) << 4) | (p))
127 #define ASYNC_PARAMS 2 /* sync_params value for async xfers */
130 * Assuming a clock frequency of 50MHz:
132 * The transfer period with SYNC_PER(sync_params) == x
133 * is (x + 2) * 40ns, except that x == 0 gives 100ns.
135 * The units of the sel_timeout register are 10ms.