sys/arch/atari/dev/zsvar.h

   1 /*      $NetBSD: zsvar.h,v 1.12 2008/04/29 06:53:01 martin Exp $        */
   2
   3 /*
   4  * Copyright (c) 1992, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This software was developed by the Computer Systems Engineering group
   8  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
   9  * contributed to Berkeley.
  10  *
  11  * All advertising materials mentioning features or use of this software
  12  * must display the following acknowledgement:
  13  *      This product includes software developed by the University of
  14  *      California, Lawrence Berkeley Laboratory.
  15  *
  16  * Redistribution and use in source and binary forms, with or without
  17  * modification, are permitted provided that the following conditions
  18  * are met:
  19  * 1. Redistributions of source code must retain the above copyright
  20  *    notice, this list of conditions and the following disclaimer.
  21  * 2. Redistributions in binary form must reproduce the above copyright
  22  *    notice, this list of conditions and the following disclaimer in the
  23  *    documentation and/or other materials provided with the distribution.
  24  * 3. Neither the name of the University nor the names of its contributors
  25  *    may be used to endorse or promote products derived from this software
  26  *    without specific prior written permission.
  27  *
  28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  38  * SUCH DAMAGE.
  39  *
  40  *      @(#)zsvar.h     8.1 (Berkeley) 6/11/93
  41  */
  42
  43 /*-
  44  * Copyright (c) 1995 The NetBSD Foundation, Inc. (Atari modifications)
  45  * All rights reserved.
  46  *
  47  * This code is derived from software contributed to The NetBSD Foundation
  48  * by Leo Weppelman.
  49  *
  50  * Redistribution and use in source and binary forms, with or without
  51  * modification, are permitted provided that the following conditions
  52  * are met:
  53  * 1. Redistributions of source code must retain the above copyright
  54  *    notice, this list of conditions and the following disclaimer.
  55  * 2. Redistributions in binary form must reproduce the above copyright
  56  *    notice, this list of conditions and the following disclaimer in the
  57  *    documentation and/or other materials provided with the distribution.
  58  *
  59  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  60  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  61  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  62  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  63  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  64  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  65  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  66  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  67  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  68  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  69  * POSSIBILITY OF SUCH DAMAGE.
  70  */
  71
  72 /*
  73  * Register layout is machine-dependent...
  74  */
  75
  76 struct zschan {
  77         u_char          zc_xxx0;
  78         volatile u_char zc_csr;         /* ctrl,status, and indirect access */
  79         u_char          zc_xxx1;
  80         volatile u_char zc_data;        /* data */
  81 };
  82
  83 struct zsdevice {
  84         struct  zschan zs_chan[2];
  85 };
  86
  87 /*
  88  * Software state, per zs channel.
  89  *
  90  * The zs chip has insufficient buffering, so we provide a software
  91  * buffer using a two-level interrupt scheme.  The hardware (high priority)
  92  * interrupt simply grabs the `cause' of the interrupt and stuffs it into
  93  * a ring buffer.  It then schedules a software interrupt; the latter
  94  * empties the ring as fast as it can, hoping to avoid overflow.
  95  *
  96  * Interrupts can happen because of:
  97  *      - received data;
  98  *      - transmit pseudo-DMA done; and
  99  *      - status change.
 100  * These are all stored together in the (single) ring.  The size of the
 101  * ring is a power of two, to make % operations fast.  Since we need two
 102  * bits to distinguish the interrupt type, and up to 16 for the received
 103  * data plus RR1 status, we use 32 bits per ring entry.
 104  *
 105  * When the value is a character + RR1 status, the character is in the
 106  * upper 8 bits of the RR1 status.
 107  */
 108 #define ZLRB_RING_SIZE          8192            /* ZS line ring buffer size */
 109 #define ZLRB_RING_MASK          8191            /* mask for same */
 110
 111 /* 0 is reserved (means "no interrupt") */
 112 #define ZRING_RINT              1               /* receive data interrupt */
 113 #define ZRING_XINT              2               /* transmit done interrupt */
 114 #define ZRING_SINT              3               /* status change interrupt */
 115
 116 #define ZRING_TYPE(x)           ((x) & 3)
 117 #define ZRING_VALUE(x)          ((x) >> 8)
 118 #define ZRING_MAKE(t, v)        ((t) | (v) << 8)
 119
 120 struct zs_chanstate {
 121         struct  zs_chanstate    *cs_next;       /* linked list for zshard() */
 122         volatile struct zschan  *cs_zc;         /* points to hardware regs */
 123         int                     cs_unit;        /* unit number */
 124         struct  tty             *cs_ttyp;       /* ### */
 125
 126         /*
 127          * We must keep a copy of the write registers as they are
 128          * mostly write-only and we sometimes need to set and clear
 129          * individual bits (e.g., in WR3).  Not all of these are
 130          * needed but 16 bytes is cheap and this makes the addressing
 131          * simpler.  Unfortunately, we can only write to some registers
 132          * when the chip is not actually transmitting, so whenever
 133          * we are expecting a `transmit done' interrupt the preg array
 134          * is allowed to `get ahead' of the current values.  In a
 135          * few places we must change the current value of a register,
 136          * rather than (or in addition to) the pending value; for these
 137          * cs_creg[] contains the current value.
 138          */
 139         u_char  cs_creg[16];            /* current values */
 140         u_char  cs_preg[16];            /* pending values */
 141         u_char  cs_heldchange;          /* change pending (creg != preg) */
 142         u_char  cs_rr0;                 /* last rr0 processed */
 143
 144         /* pure software data, per channel */
 145         char    cs_softcar;             /* software carrier */
 146         char    cs_xxx;                 /* (spare) */
 147
 148         /*
 149          * The transmit byte count and address are used for pseudo-DMA
 150          * output in the hardware interrupt code.  PDMA can be suspended
 151          * to get pending changes done; heldtbc is used for this.  It can
 152          * also be stopped for ^S; this sets TS_TTSTOP in tp->t_state.
 153          */
 154         int     cs_tbc;                 /* transmit byte count */
 155         uint8_t *cs_tba;                /* transmit buffer address */
 156         int     cs_heldtbc;             /* held tbc while xmission stopped */
 157
 158         /*
 159          * Printing an overrun error message often takes long enough to
 160          * cause another overrun, so we only print one per second.
 161          */
 162         long    cs_rotime;              /* time of last ring overrun */
 163         long    cs_fotime;              /* time of last fifo overrun */
 164
 165         /*
 166          * The ring buffer.
 167          */
 168         u_int           cs_rbget;       /* ring buffer `get' index      */
 169         volatile u_int  cs_rbput;       /* ring buffer `put' index      */
 170         int             *cs_rbuf;       /* type, value pairs    */
 171 };
 172
 173 #define ZS_CHAN_A       0
 174 #define ZS_CHAN_B       1
 175
 176 /*
 177  * Macros to read and write individual registers (except 0) in a channel.
 178  */
 179 #define ZS_READ(c, r)           ((c)->zc_csr = (r), (c)->zc_csr)
 180 #define ZS_WRITE(c, r, v)       ((c)->zc_csr = (r), (c)->zc_csr = (v))
 181
 182 /*
 183  * Split minor into unit, dialin/dialout & flag nibble.
 184  */
 185 #define ZS_UNIT(dev)            ((minor(dev) >> 4) & 0xf)
 186 #define ZS_FLAGS(dev)           (minor(dev) & 0xf)
 187 #define ZS_DIALOUT(dev)         (minor(dev) & 0x80000)