1 /* $NetBSD: zsvar.h,v 1.6 1998/03/25 09:46:10 leo Exp $ */ 2 3 /* 4 * Copyright (c) 1995 Leo Weppelman (Atari modifications) 5 * Copyright (c) 1992, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This software was developed by the Computer Systems Engineering group 9 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 10 * contributed to Berkeley. 11 * 12 * All advertising materials mentioning features or use of this software 13 * must display the following acknowledgement: 14 * This product includes software developed by the University of 15 * California, Lawrence Berkeley Laboratory. 16 * 17 * Redistribution and use in source and binary forms, with or without 18 * modification, are permitted provided that the following conditions 19 * are met: 20 * 1. Redistributions of source code must retain the above copyright 21 * notice, this list of conditions and the following disclaimer. 22 * 2. Redistributions in binary form must reproduce the above copyright 23 * notice, this list of conditions and the following disclaimer in the 24 * documentation and/or other materials provided with the distribution. 25 * 3. All advertising materials mentioning features or use of this software 26 * must display the following acknowledgement: 27 * This product includes software developed by the University of 28 * California, Berkeley and its contributors. 29 * 4. Neither the name of the University nor the names of its contributors 30 * may be used to endorse or promote products derived from this software 31 * without specific prior written permission. 32 * 33 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 34 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 35 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 36 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 37 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 38 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 39 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 40 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 41 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 42 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 43 * SUCH DAMAGE. 44 * 45 * @(#)zsvar.h 8.1 (Berkeley) 6/11/93 46 */ 47 48 /* 49 * Register layout is machine-dependent... 50 */ 51 52 struct zschan { 53 u_char zc_xxx0; 54 volatile u_char zc_csr; /* ctrl,status, and indirect access */ 55 u_char zc_xxx1; 56 volatile u_char zc_data; /* data */ 57 }; 58 59 struct zsdevice { 60 struct zschan zs_chan[2]; 61 }; 62 63 /* 64 * Software state, per zs channel. 65 * 66 * The zs chip has insufficient buffering, so we provide a software 67 * buffer using a two-level interrupt scheme. The hardware (high priority) 68 * interrupt simply grabs the `cause' of the interrupt and stuffs it into 69 * a ring buffer. It then schedules a software interrupt; the latter 70 * empties the ring as fast as it can, hoping to avoid overflow. 71 * 72 * Interrupts can happen because of: 73 * - received data; 74 * - transmit pseudo-DMA done; and 75 * - status change. 76 * These are all stored together in the (single) ring. The size of the 77 * ring is a power of two, to make % operations fast. Since we need two 78 * bits to distinguish the interrupt type, and up to 16 for the received 79 * data plus RR1 status, we use 32 bits per ring entry. 80 * 81 * When the value is a character + RR1 status, the character is in the 82 * upper 8 bits of the RR1 status. 83 */ 84 #define ZLRB_RING_SIZE 4096 /* ZS line ring buffer size */ 85 #define ZLRB_RING_MASK 4095 /* mask for same */ 86 87 /* 0 is reserved (means "no interrupt") */ 88 #define ZRING_RINT 1 /* receive data interrupt */ 89 #define ZRING_XINT 2 /* transmit done interrupt */ 90 #define ZRING_SINT 3 /* status change interrupt */ 91 92 #define ZRING_TYPE(x) ((x) & 3) 93 #define ZRING_VALUE(x) ((x) >> 8) 94 #define ZRING_MAKE(t, v) ((t) | (v) << 8) 95 96 struct zs_chanstate { 97 struct zs_chanstate *cs_next; /* linked list for zshard() */ 98 volatile struct zschan *cs_zc; /* points to hardware regs */ 99 int cs_unit; /* unit number */ 100 struct tty *cs_ttyp; /* ### */ 101 102 /* 103 * We must keep a copy of the write registers as they are 104 * mostly write-only and we sometimes need to set and clear 105 * individual bits (e.g., in WR3). Not all of these are 106 * needed but 16 bytes is cheap and this makes the addressing 107 * simpler. Unfortunately, we can only write to some registers 108 * when the chip is not actually transmitting, so whenever 109 * we are expecting a `transmit done' interrupt the preg array 110 * is allowed to `get ahead' of the current values. In a 111 * few places we must change the current value of a register, 112 * rather than (or in addition to) the pending value; for these 113 * cs_creg[] contains the current value. 114 */ 115 u_char cs_creg[16]; /* current values */ 116 u_char cs_preg[16]; /* pending values */ 117 u_char cs_heldchange; /* change pending (creg != preg) */ 118 u_char cs_rr0; /* last rr0 processed */ 119 120 /* pure software data, per channel */ 121 char cs_softcar; /* software carrier */ 122 char cs_xxx; /* (spare) */ 123 124 /* 125 * The transmit byte count and address are used for pseudo-DMA 126 * output in the hardware interrupt code. PDMA can be suspended 127 * to get pending changes done; heldtbc is used for this. It can 128 * also be stopped for ^S; this sets TS_TTSTOP in tp->t_state. 129 */ 130 int cs_tbc; /* transmit byte count */ 131 caddr_t cs_tba; /* transmit buffer address */ 132 int cs_heldtbc; /* held tbc while xmission stopped */ 133 134 /* 135 * Printing an overrun error message often takes long enough to 136 * cause another overrun, so we only print one per second. 137 */ 138 long cs_rotime; /* time of last ring overrun */ 139 long cs_fotime; /* time of last fifo overrun */ 140 141 /* 142 * The ring buffer. 143 */ 144 u_int cs_rbget; /* ring buffer `get' index */ 145 volatile u_int cs_rbput; /* ring buffer `put' index */ 146 int *cs_rbuf; /* type, value pairs */ 147 }; 148 149 #define ZS_CHAN_A 0 150 #define ZS_CHAN_B 1 151 152 /* 153 * Macros to read and write individual registers (except 0) in a channel. 154 */ 155 #define ZS_READ(c, r) ((c)->zc_csr = (r), (c)->zc_csr) 156 #define ZS_WRITE(c, r, v) ((c)->zc_csr = (r), (c)->zc_csr = (v)) 157 158 /* 159 * Split minor into unit, dialin/dialout & flag nibble. 160 */ 161 #define ZS_UNIT(dev) ((minor(dev) >> 4) & 0xf) 162 #define ZS_FLAGS(dev) (minor(dev) & 0xf) 163 #define ZS_DIALOUT(dev) (minor(dev) & 0x80000) 164