/* $NetBSD: zsvar.h,v 1.3 1995/11/30 00:58:00 jtc Exp $ */ /* * Copyright (c) 1995 Leo Weppelman (Atari modifications) * Copyright (c) 1992, 1993 * The Regents of the University of California. All rights reserved. * * This software was developed by the Computer Systems Engineering group * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and * contributed to Berkeley. * * All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Lawrence Berkeley Laboratory. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)zsvar.h 8.1 (Berkeley) 6/11/93 */ /* * Software state, per zs channel. * * The zs chip has insufficient buffering, so we provide a software * buffer using a two-level interrupt scheme. The hardware (high priority) * interrupt simply grabs the `cause' of the interrupt and stuffs it into * a ring buffer. It then schedules a software interrupt; the latter * empties the ring as fast as it can, hoping to avoid overflow. * * Interrupts can happen because of: * - received data; * - transmit pseudo-DMA done; and * - status change. * These are all stored together in the (single) ring. The size of the * ring is a power of two, to make % operations fast. Since we need two * bits to distinguish the interrupt type, and up to 16 for the received * data plus RR1 status, we use 32 bits per ring entry. * * When the value is a character + RR1 status, the character is in the * upper 8 bits of the RR1 status. */ #define ZLRB_RING_SIZE 4096 /* ZS line ring buffer size */ #define ZLRB_RING_MASK 4095 /* mask for same */ /* 0 is reserved (means "no interrupt") */ #define ZRING_RINT 1 /* receive data interrupt */ #define ZRING_XINT 2 /* transmit done interrupt */ #define ZRING_SINT 3 /* status change interrupt */ #define ZRING_TYPE(x) ((x) & 3) #define ZRING_VALUE(x) ((x) >> 8) #define ZRING_MAKE(t, v) ((t) | (v) << 8) struct zs_chanstate { struct zs_chanstate *cs_next; /* linked list for zshard() */ volatile struct zschan *cs_zc; /* points to hardware regs */ int cs_unit; /* unit number */ struct tty *cs_ttyp; /* ### */ /* * We must keep a copy of the write registers as they are * mostly write-only and we sometimes need to set and clear * individual bits (e.g., in WR3). Not all of these are * needed but 16 bytes is cheap and this makes the addressing * simpler. Unfortunately, we can only write to some registers * when the chip is not actually transmitting, so whenever * we are expecting a `transmit done' interrupt the preg array * is allowed to `get ahead' of the current values. In a * few places we must change the current value of a register, * rather than (or in addition to) the pending value; for these * cs_creg[] contains the current value. */ u_char cs_creg[16]; /* current values */ u_char cs_preg[16]; /* pending values */ u_char cs_heldchange; /* change pending (creg != preg) */ u_char cs_rr0; /* last rr0 processed */ /* pure software data, per channel */ char cs_softcar; /* software carrier */ char cs_xxx; /* (spare) */ /* * The transmit byte count and address are used for pseudo-DMA * output in the hardware interrupt code. PDMA can be suspended * to get pending changes done; heldtbc is used for this. It can * also be stopped for ^S; this sets TS_TTSTOP in tp->t_state. */ int cs_tbc; /* transmit byte count */ caddr_t cs_tba; /* transmit buffer address */ int cs_heldtbc; /* held tbc while xmission stopped */ /* * Printing an overrun error message often takes long enough to * cause another overrun, so we only print one per second. */ long cs_rotime; /* time of last ring overrun */ long cs_fotime; /* time of last fifo overrun */ /* * The ring buffer. */ u_int cs_rbget; /* ring buffer `get' index */ volatile u_int cs_rbput; /* ring buffer `put' index */ int cs_rbuf[ZLRB_RING_SIZE];/* type, value pairs */ }; #define ZS_CHAN_A 0 #define ZS_CHAN_B 1 /* * Macros to read and write individual registers (except 0) in a channel. */ #define ZS_READ(c, r) ((c)->zc_csr = (r), (c)->zc_csr) #define ZS_WRITE(c, r, v) ((c)->zc_csr = (r), (c)->zc_csr = (v)) /* * Split minor into unit & flag nibble. */ #define ZS_UNIT(dev) ((minor(dev) >> 4) & 0xf) #define ZS_FLAGS(dev) (minor(dev) & 0xf)