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      1 /*	$NetBSD: zsvar.h,v 1.18 2023/01/06 10:28:28 tsutsui 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 	uint8_t zc_xxx0;
     78 	volatile uint8_t zc_csr;	/* ctrl,status, and indirect access */
     79 	uint8_t zc_xxx1;
     80 	volatile uint8_t zc_data;	/* data */
     81 };
     82 
     83 struct zsdevice {
     84 	struct	zschan zs_chan_a;
     85 	struct	zschan zs_chan_b;
     86 };
     87 
     88 /*
     89  * Software state, per zs channel.
     90  *
     91  * The zs chip has insufficient buffering, so we provide a software
     92  * buffer using a two-level interrupt scheme.  The hardware (high priority)
     93  * interrupt simply grabs the `cause' of the interrupt and stuffs it into
     94  * a ring buffer.  It then schedules a software interrupt; the latter
     95  * empties the ring as fast as it can, hoping to avoid overflow.
     96  *
     97  * Interrupts can happen because of:
     98  *	- received data;
     99  *	- transmit pseudo-DMA done; and
    100  *	- status change.
    101  * These are all stored together in the (single) ring.  The size of the
    102  * ring is a power of two, to make % operations fast.  Since we need two
    103  * bits to distinguish the interrupt type, and up to 16 for the received
    104  * data plus RR1 status, we use 32 bits per ring entry.
    105  *
    106  * When the value is a character + RR1 status, the character is in the
    107  * upper 8 bits of the RR1 status.
    108  */
    109 #define ZLRB_RING_SIZE		8192		/* ZS line ring buffer size */
    110 #define	ZLRB_RING_MASK		8191		/* mask for same */
    111 
    112 /* 0 is reserved (means "no interrupt") */
    113 #define	ZRING_RINT		1		/* receive data interrupt */
    114 #define	ZRING_XINT		2		/* transmit done interrupt */
    115 #define	ZRING_SINT		3		/* status change interrupt */
    116 
    117 #define	ZRING_TYPE(x)		((x) & 3)
    118 #define	ZRING_VALUE(x)		((x) >> 8)
    119 #define	ZRING_MAKE(t, v)	((t) | (v) << 8)
    120 
    121 struct zs_chanstate {
    122 	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 	uint8_t	cs_creg[16];		/* current values */
    140 	uint8_t	cs_preg[16];		/* pending values */
    141 	uint8_t	cs_heldchange;		/* change pending (creg != preg) */
    142 	uint8_t	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 /*
    174  * Macros to read and write individual registers (except 0) in a channel.
    175  */
    176 #define	ZS_READ(c, r)		((c)->zc_csr = (r), (c)->zc_csr)
    177 #define	ZS_WRITE(c, r, v)	((c)->zc_csr = (r), (c)->zc_csr = (v))
    178 
    179 /*
    180  * Split minor into unit, dialin/dialout & flag nibble.
    181  */
    182 #define	ZS_UNIT(dev)		(TTUNIT(dev) >> 4)
    183 #define	ZS_FLAGS(dev)		(TTUNIT(dev) & 0xf)
    184 #define	ZS_DIALOUT(dev)		TTDIALOUT(dev)
    185