NetBSD/sys/dev/ic/z8530sc.c
gwr 4371d4ef78 Remove the while loop from zsc_intr_hard(). It caused problems on
some machines, and those that really want to can just call this
function in a loop until it returns zero.
1997-10-04 22:30:30 +00:00

333 lines
8.7 KiB
C

/* $NetBSD: z8530sc.c,v 1.6 1997/10/04 22:30:30 gwr Exp $ */
/*
* Copyright (c) 1994 Gordon W. Ross
* 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.
*
* @(#)zs.c 8.1 (Berkeley) 7/19/93
*/
/*
* Zilog Z8530 Dual UART driver (common part)
*
* This file contains the machine-independent parts of the
* driver common to tty and keyboard/mouse sub-drivers.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/device.h>
#include <sys/conf.h>
#include <sys/file.h>
#include <sys/ioctl.h>
#include <sys/tty.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/syslog.h>
#include <dev/ic/z8530reg.h>
#include <machine/z8530var.h>
void
zs_break(cs, set)
struct zs_chanstate *cs;
int set;
{
int s;
s = splzs();
if (set) {
cs->cs_preg[5] |= ZSWR5_BREAK;
cs->cs_creg[5] |= ZSWR5_BREAK;
} else {
cs->cs_preg[5] &= ~ZSWR5_BREAK;
cs->cs_creg[5] &= ~ZSWR5_BREAK;
}
zs_write_reg(cs, 5, cs->cs_creg[5]);
splx(s);
}
/*
* drain on-chip fifo
*/
void
zs_iflush(cs)
struct zs_chanstate *cs;
{
u_char c, rr0, rr1;
for (;;) {
/* Is there input available? */
rr0 = zs_read_csr(cs);
if ((rr0 & ZSRR0_RX_READY) == 0)
break;
/*
* First read the status, because reading the data
* destroys the status of this char.
*/
rr1 = zs_read_reg(cs, 1);
c = zs_read_data(cs);
if (rr1 & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE)) {
/* Clear the receive error. */
zs_write_csr(cs, ZSWR0_RESET_ERRORS);
}
}
}
/*
* Write the given register set to the given zs channel in the proper order.
* The channel must not be transmitting at the time. The receiver will
* be disabled for the time it takes to write all the registers.
* Call this with interrupts disabled.
*/
void
zs_loadchannelregs(cs)
struct zs_chanstate *cs;
{
u_char *reg;
/* Copy "pending" regs to "current" */
bcopy((caddr_t)cs->cs_preg, (caddr_t)cs->cs_creg, 16);
reg = cs->cs_creg; /* current regs */
zs_write_csr(cs, ZSM_RESET_ERR); /* XXX: reset error condition */
#if 1
/*
* XXX: Is this really a good idea?
* XXX: Should go elsewhere! -gwr
*/
zs_iflush(cs); /* XXX */
#endif
/* disable interrupts */
zs_write_reg(cs, 1, reg[1] & ~ZSWR1_IMASK);
/* baud clock divisor, stop bits, parity */
zs_write_reg(cs, 4, reg[4]);
/* misc. TX/RX control bits */
zs_write_reg(cs, 10, reg[10]);
/* char size, enable (RX/TX) */
zs_write_reg(cs, 3, reg[3] & ~ZSWR3_RX_ENABLE);
zs_write_reg(cs, 5, reg[5] & ~ZSWR5_TX_ENABLE);
/* synchronous mode stuff */
zs_write_reg(cs, 6, reg[6]);
zs_write_reg(cs, 7, reg[7]);
#if 0
/*
* Registers 2 and 9 are special because they are
* actually common to both channels, but must be
* programmed through channel A. The "zsc" attach
* function takes care of setting these registers
* and they should not be touched thereafter.
*/
/* interrupt vector */
zs_write_reg(cs, 2, reg[2]);
/* master interrupt control */
zs_write_reg(cs, 9, reg[9]);
#endif
/* Shut down the BRG */
zs_write_reg(cs, 14, reg[14] & ~ZSWR14_BAUD_ENA);
#ifdef ZS_MD_SETCLK
/* Let the MD code setup any external clock. */
ZS_MD_SETCLK(cs);
#endif /* ZS_MD_SETCLK */
/* clock mode control */
zs_write_reg(cs, 11, reg[11]);
/* baud rate (lo/hi) */
zs_write_reg(cs, 12, reg[12]);
zs_write_reg(cs, 13, reg[13]);
/* Misc. control bits */
zs_write_reg(cs, 14, reg[14]);
/* which lines cause status interrupts */
zs_write_reg(cs, 15, reg[15]);
/*
* Zilog docs recommend resetting external status twice at this
* point. Mainly as the status bits are latched, and the first
* interrupt clear might unlatch them to new values, generating
* a second interrupt request.
*/
zs_write_csr(cs, ZSM_RESET_STINT);
zs_write_csr(cs, ZSM_RESET_STINT);
/* char size, enable (RX/TX)*/
zs_write_reg(cs, 3, reg[3]);
zs_write_reg(cs, 5, reg[5]);
/* interrupt enables: RX, TX, STATUS */
zs_write_reg(cs, 1, reg[1]);
}
/*
* ZS hardware interrupt. Scan all ZS channels. NB: we know here that
* channels are kept in (A,B) pairs.
*
* Do just a little, then get out; set a software interrupt if more
* work is needed.
*
* We deliberately ignore the vectoring Zilog gives us, and match up
* only the number of `reset interrupt under service' operations, not
* the order.
*/
int
zsc_intr_hard(arg)
void *arg;
{
struct zsc_softc *zsc = arg;
register struct zs_chanstate *cs;
register u_char rr3;
/* First look at channel A. */
cs = zsc->zsc_cs[0];
/* Note: only channel A has an RR3 */
rr3 = zs_read_reg(cs, 3);
/*
* Clear interrupt first to avoid a race condition.
* If a new interrupt condition happens while we are
* servicing this one, we will get another interrupt
* shortly. We can NOT just sit here in a loop, or
* we will cause horrible latency for other devices
* on this interrupt level (i.e. sun3x floppy disk).
*/
if (rr3 & (ZSRR3_IP_A_RX | ZSRR3_IP_A_TX | ZSRR3_IP_A_STAT)) {
zs_write_csr(cs, ZSWR0_CLR_INTR);
if (rr3 & ZSRR3_IP_A_RX)
(*cs->cs_ops->zsop_rxint)(cs);
if (rr3 & ZSRR3_IP_A_STAT)
(*cs->cs_ops->zsop_stint)(cs);
if (rr3 & ZSRR3_IP_A_TX)
(*cs->cs_ops->zsop_txint)(cs);
}
/* Now look at channel B. */
cs = zsc->zsc_cs[1];
if (rr3 & (ZSRR3_IP_B_RX | ZSRR3_IP_B_TX | ZSRR3_IP_B_STAT)) {
zs_write_csr(cs, ZSWR0_CLR_INTR);
if (rr3 & ZSRR3_IP_B_RX)
(*cs->cs_ops->zsop_rxint)(cs);
if (rr3 & ZSRR3_IP_B_STAT)
(*cs->cs_ops->zsop_stint)(cs);
if (rr3 & ZSRR3_IP_B_TX)
(*cs->cs_ops->zsop_txint)(cs);
}
/* Note: caller will check cs_x->cs_softreq and DTRT. */
return (rr3);
}
/*
* ZS software interrupt. Scan all channels for deferred interrupts.
*/
int
zsc_intr_soft(arg)
void *arg;
{
register struct zsc_softc *zsc = arg;
register struct zs_chanstate *cs;
register int rval, chan;
rval = 0;
for (chan = 0; chan < 2; chan++) {
cs = zsc->zsc_cs[chan];
/*
* The softint flag can be safely cleared once
* we have decided to call the softint routine.
* (No need to do splzs() first.)
*/
if (cs->cs_softreq) {
cs->cs_softreq = 0;
(*cs->cs_ops->zsop_softint)(cs);
rval++;
}
}
return (rval);
}
/*
* Provide a null zs "ops" vector.
*/
static void zsnull_intr __P((struct zs_chanstate *));
static void zsnull_softint __P((struct zs_chanstate *));
static void
zsnull_intr(cs)
struct zs_chanstate *cs;
{
/* Ask for softint() call. */
cs->cs_softreq = 1;
}
static void
zsnull_softint(cs)
struct zs_chanstate *cs;
{
zs_write_reg(cs, 1, 0);
zs_write_reg(cs, 15, 0);
}
struct zsops zsops_null = {
zsnull_intr, /* receive char available */
zsnull_intr, /* external/status */
zsnull_intr, /* xmit buffer empty */
zsnull_softint, /* process software interrupt */
};