/*
* 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. 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.
*/
/* 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 */
struct zs_chanstate {
struct zs_chanstate *cs_next; /* linked list for zshard() */
struct zs_softc *cs_sc; /* pointer to softc */
volatile struct zschan *cs_zc; /* points to hardware regs */
struct tty *cs_ttyp; /* ### */
int cs_unit; /* unit number */
/*
* 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.
*/
uint8_t cs_creg[16]; /* current values */
uint8_t cs_preg[16]; /* pending values */
uint8_t cs_heldchange; /* change pending (creg != preg) */
uint8_t cs_rr0; /* last rr0 processed */
/* pure software data, per channel */
char cs_softcar; /* software carrier */
char cs_conk; /* is console keyboard, decode L1-A */
char cs_brkabort; /* abort (as if via L1-A) on BREAK */
char cs_kgdb; /* enter debugger on frame char */
char cs_consio; /* port does /dev/console I/O */
char cs_xxx; /* (spare) */
int cs_speed; /* default baud rate (from ROM) */
/*
* 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 */
int cs_heldtbc; /* held tbc while xmission stopped */
void * cs_tba; /* transmit buffer address */
/*
* 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 */
u_int cs_ringmask; /* mask, reflecting size of `rbuf' */
int *cs_rbuf; /* type, value pairs */
};
/*
* N.B.: the keyboard is channel 1, the mouse channel 0; ttyb is 1, ttya
* is 0. In other words, the things are BACKWARDS.
*/
#define ZS_CHAN_A 1
#define ZS_CHAN_B 0
/*
* Macros to read and write individual registers (except 0) in a channel.
*
* On the SparcStation the 1.6 microsecond recovery time is
* handled in hardware. On the older Sun4 machine it isn't, and
* software must deal with the problem.
*
* However, it *is* a problem on some Sun4m's (i.e. the SS20) (XXX: why?).
* Thus we leave in the delay.
*
* XXX: (ABB) Think about this more.
*/
#if 0
