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 15 struct 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 */ 129