0c3c54da63
uses the i8237 without trying to emulate the PC architecture move the register definitions for the i8237 chip into the central include file for the chip, except for the PC98 case which is magic. Add new isa_dmatc() function which tells us as cheaply as possible if the terminal count has been reached for a given channel.
509 lines
13 KiB
C
509 lines
13 KiB
C
/*-
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* Copyright (c) 1991 The Regents of the University of California.
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* All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* William Jolitz.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* from: @(#)isa.c 7.2 (Berkeley) 5/13/91
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* from: isa_dma.c,v 1.3 1999/05/09 23:56:00 peter Exp $
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* $FreeBSD$
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*/
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/*
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* code to manage AT bus
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*
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* 92/08/18 Frank P. MacLachlan (fpm@crash.cts.com):
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* Fixed uninitialized variable problem and added code to deal
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* with DMA page boundaries in isa_dmarangecheck(). Fixed word
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* mode DMA count compution and reorganized DMA setup code in
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* isa_dmastart()
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/malloc.h>
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#include <sys/lock.h>
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#include <sys/mutex.h>
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#include <sys/bus.h>
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#include <vm/vm.h>
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#include <vm/vm_param.h>
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#include <vm/pmap.h>
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#include <isa/isareg.h>
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#include <isa/isavar.h>
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#include <dev/ic/i8237.h>
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#include <machine/bus.h>
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static bus_dma_tag_t dma_tag[8];
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static bus_dmamap_t dma_map[8];
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static u_int8_t dma_busy = 0; /* Used in isa_dmastart() */
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static u_int8_t dma_inuse = 0; /* User for acquire/release */
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static u_int8_t dma_auto_mode = 0;
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static u_int8_t dma_bounced = 0;
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#define VALID_DMA_MASK (7)
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/* high byte of address is stored in this port for i-th dma channel */
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static int dmapageport[8] = { 0x87, 0x83, 0x81, 0x82, 0x8f, 0x8b, 0x89, 0x8a };
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/*
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* Setup a DMA channel's bounce buffer.
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*/
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int
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isa_dma_init(int chan, u_int bouncebufsize, int flag __unused)
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{
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static int initted = 0;
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bus_addr_t boundary = chan >= 4 ? 0x20000 : 0x10000;
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if (!initted) {
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/*
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* Reset the DMA hardware.
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*/
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outb(DMA1_RESET, 0);
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outb(DMA2_RESET, 0);
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isa_dmacascade(4);
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initted = 1;
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}
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#ifdef DIAGNOSTIC
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if (chan & ~VALID_DMA_MASK)
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panic("isa_dma_init: channel out of range");
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if (dma_tag[chan] || dma_map[chan])
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panic("isa_dma_init: impossible request");
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#endif
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if (bus_dma_tag_create(/*parent*/NULL,
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/*alignment*/2,
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/*boundary*/boundary,
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/*lowaddr*/BUS_SPACE_MAXADDR_24BIT,
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/*highaddr*/BUS_SPACE_MAXADDR,
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/*filter*/NULL, /*filterarg*/NULL,
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/*maxsize*/bouncebufsize,
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/*nsegments*/1, /*maxsegz*/0x3ffff,
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/*flags*/BUS_DMA_ISA,
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/*lockfunc*/busdma_lock_mutex,
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/*lockarg*/&Giant,
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&dma_tag[chan]) != 0) {
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panic("isa_dma_init: unable to create dma tag\n");
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}
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if (bus_dmamap_create(dma_tag[chan], 0, &dma_map[chan])) {
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panic("isa_dma_init: unable to create dma map\n");
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}
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return (0);
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}
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/*
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* Register a DMA channel's usage. Usually called from a device driver
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* in open() or during its initialization.
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*/
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int
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isa_dma_acquire(chan)
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int chan;
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{
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#ifdef DIAGNOSTIC
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if (chan & ~VALID_DMA_MASK)
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panic("isa_dma_acquire: channel out of range");
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#endif
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if (dma_inuse & (1 << chan)) {
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printf("isa_dma_acquire: channel %d already in use\n", chan);
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return (EBUSY);
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}
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dma_inuse |= (1 << chan);
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dma_auto_mode &= ~(1 << chan);
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return (0);
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}
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/*
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* Unregister a DMA channel's usage. Usually called from a device driver
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* during close() or during its shutdown.
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*/
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void
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isa_dma_release(chan)
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int chan;
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{
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#ifdef DIAGNOSTIC
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if (chan & ~VALID_DMA_MASK)
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panic("isa_dma_release: channel out of range");
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if ((dma_inuse & (1 << chan)) == 0)
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printf("isa_dma_release: channel %d not in use\n", chan);
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#endif
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if (dma_busy & (1 << chan)) {
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dma_busy &= ~(1 << chan);
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/*
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* XXX We should also do "dma_bounced &= (1 << chan);"
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* because we are acting on behalf of isa_dmadone() which
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* was not called to end the last DMA operation. This does
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* not matter now, but it may in the future.
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*/
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}
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dma_inuse &= ~(1 << chan);
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dma_auto_mode &= ~(1 << chan);
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}
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/*
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* isa_dmacascade(): program 8237 DMA controller channel to accept
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* external dma control by a board.
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*/
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void
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isa_dmacascade(chan)
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int chan;
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{
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#ifdef DIAGNOSTIC
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if (chan & ~VALID_DMA_MASK)
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panic("isa_dmacascade: channel out of range");
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#endif
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/* set dma channel mode, and set dma channel mode */
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if ((chan & 4) == 0) {
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outb(DMA1_MODE, DMA37MD_CASCADE | chan);
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outb(DMA1_SMSK, chan);
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} else {
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outb(DMA2_MODE, DMA37MD_CASCADE | (chan & 3));
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outb(DMA2_SMSK, chan & 3);
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}
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}
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/*
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* isa_dmastart(): program 8237 DMA controller channel.
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*/
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struct isa_dmastart_arg {
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caddr_t addr;
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int chan;
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int flags;
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};
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static void isa_dmastart_cb(void *arg, bus_dma_segment_t *segs, int nseg,
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int error)
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{
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#if 0
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caddr_t addr = ((struct isa_dmastart_arg *) arg)->addr;
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#endif
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int chan = ((struct isa_dmastart_arg *) arg)->chan;
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int flags = ((struct isa_dmastart_arg *) arg)->flags;
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bus_addr_t phys = segs->ds_addr;
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int nbytes = segs->ds_len;
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int waport;
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if (nseg != 1)
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panic("isa_dmastart: transfer mapping not contiguous");
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#if 0
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if ((chipset.sgmap == NULL) &&
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(pmap_extract(kernel_pmap, (vm_offset_t)addr)
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> BUS_SPACE_MAXADDR_24BIT)) {
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/* we bounced */
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dma_bounced |= (1 << chan);
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/* copy bounce buffer on write */
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if (!(flags & ISADMA_READ))
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bus_dmamap_sync(dma_tag[chan], dma_map[chan],
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BUS_DMASYNC_PREWRITE);
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}
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#endif
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if ((chan & 4) == 0) {
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/*
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* Program one of DMA channels 0..3. These are
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* byte mode channels.
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*/
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/* set dma channel mode, and reset address ff */
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/* If ISADMA_RAW flag is set, then use autoinitialise mode */
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if (flags & ISADMA_RAW) {
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if (flags & ISADMA_READ)
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outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_WRITE|chan);
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else
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outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_READ|chan);
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}
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else
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if (flags & ISADMA_READ)
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outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|chan);
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else
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outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_READ|chan);
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outb(DMA1_FFC, 0);
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/* send start address */
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waport = DMA1_CHN(chan);
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outb(waport, phys);
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outb(waport, phys>>8);
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outb(dmapageport[chan], phys>>16);
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/* send count */
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outb(waport + 1, --nbytes);
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outb(waport + 1, nbytes>>8);
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/* unmask channel */
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outb(DMA1_SMSK, chan);
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} else {
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/*
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* Program one of DMA channels 4..7. These are
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* word mode channels.
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*/
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/* set dma channel mode, and reset address ff */
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/* If ISADMA_RAW flag is set, then use autoinitialise mode */
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if (flags & ISADMA_RAW) {
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if (flags & ISADMA_READ)
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outb(DMA2_MODE, DMA37MD_AUTO|DMA37MD_WRITE|(chan&3));
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else
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outb(DMA2_MODE, DMA37MD_AUTO|DMA37MD_READ|(chan&3));
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}
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else
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if (flags & ISADMA_READ)
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outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|(chan&3));
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else
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outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_READ|(chan&3));
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outb(DMA2_FFC, 0);
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/* send start address */
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waport = DMA2_CHN(chan - 4);
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outb(waport, phys>>1);
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outb(waport, phys>>9);
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outb(dmapageport[chan], phys>>16);
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/* send count */
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nbytes >>= 1;
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outb(waport + 2, --nbytes);
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outb(waport + 2, nbytes>>8);
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/* unmask channel */
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outb(DMA2_SMSK, chan & 3);
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}
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}
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void
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isa_dmastart(int flags, caddr_t addr, u_int nbytes, int chan)
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{
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struct isa_dmastart_arg args;
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#ifdef DIAGNOSTIC
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if (chan & ~VALID_DMA_MASK)
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panic("isa_dmastart: channel out of range");
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if ((chan < 4 && nbytes > (1<<16))
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|| (chan >= 4 && (nbytes > (1<<17) || (uintptr_t)addr & 1)))
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panic("isa_dmastart: impossible request");
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if ((dma_inuse & (1 << chan)) == 0)
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printf("isa_dmastart: channel %d not acquired\n", chan);
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#endif
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#if 0
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/*
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* XXX This should be checked, but drivers like ad1848 only call
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* isa_dmastart() once because they use Auto DMA mode. If we
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* leave this in, drivers that do this will print this continuously.
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*/
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if (dma_busy & (1 << chan))
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printf("isa_dmastart: channel %d busy\n", chan);
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#endif
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if (!dma_tag || !dma_map[chan])
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panic("isa_dmastart: called without isa_dma_init");
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dma_busy |= (1 << chan);
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if (flags & ISADMA_RAW) {
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dma_auto_mode |= (1 << chan);
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} else {
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dma_auto_mode &= ~(1 << chan);
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}
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/*
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* Freeze dma while updating registers.
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*/
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outb(chan & 4 ? DMA2_SMSK : DMA1_SMSK, (chan & 3) | 4);
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args.addr = addr;
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args.chan = chan;
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args.flags = flags;
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bus_dmamap_load(dma_tag[chan], dma_map[chan], addr, nbytes,
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isa_dmastart_cb, &args, 0);
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}
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void
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isa_dmadone(int flags, caddr_t addr, int nbytes, int chan)
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{
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#ifdef DIAGNOSTIC
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if (chan & ~VALID_DMA_MASK)
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panic("isa_dmadone: channel out of range");
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if ((dma_inuse & (1 << chan)) == 0)
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printf("isa_dmadone: channel %d not acquired\n", chan);
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#endif
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if (((dma_busy & (1 << chan)) == 0) &&
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(dma_auto_mode & (1 << chan)) == 0 )
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printf("isa_dmadone: channel %d not busy\n", chan);
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if (dma_bounced & (1 << chan)) {
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/* copy bounce buffer on read */
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if (flags & ISADMA_READ) {
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bus_dmamap_sync(dma_tag[chan], dma_map[chan],
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BUS_DMASYNC_POSTREAD);
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}
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dma_bounced &= ~(1 << chan);
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}
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if ((dma_auto_mode & (1 << chan)) == 0) {
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outb(chan & 4 ? DMA2_SMSK : DMA1_SMSK, (chan & 3) | 4);
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bus_dmamap_unload(dma_tag[chan], dma_map[chan]);
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}
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dma_busy &= ~(1 << chan);
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}
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/*
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* Query the progress of a transfer on a DMA channel.
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*
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* To avoid having to interrupt a transfer in progress, we sample
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* each of the high and low databytes twice, and apply the following
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* logic to determine the correct count.
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*
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* Reads are performed with interrupts disabled, thus it is to be
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* expected that the time between reads is very small. At most
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* one rollover in the low count byte can be expected within the
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* four reads that are performed.
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*
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* There are three gaps in which a rollover can occur :
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*
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* - read low1
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* gap1
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* - read high1
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* gap2
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* - read low2
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* gap3
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* - read high2
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*
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* If a rollover occurs in gap1 or gap2, the low2 value will be
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* greater than the low1 value. In this case, low2 and high2 are a
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* corresponding pair.
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*
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* In any other case, low1 and high1 can be considered to be correct.
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*
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* The function returns the number of bytes remaining in the transfer,
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* or -1 if the channel requested is not active.
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*
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*/
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int
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isa_dmastatus(int chan)
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{
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u_long cnt = 0;
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int ffport, waport;
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u_long low1, high1, low2, high2;
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int s;
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/* channel active? */
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if ((dma_inuse & (1 << chan)) == 0) {
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printf("isa_dmastatus: channel %d not active\n", chan);
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return(-1);
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}
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/* channel busy? */
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if (((dma_busy & (1 << chan)) == 0) &&
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(dma_auto_mode & (1 << chan)) == 0 ) {
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printf("chan %d not busy\n", chan);
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return -2 ;
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}
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if (chan < 4) { /* low DMA controller */
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ffport = DMA1_FFC;
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waport = DMA1_CHN(chan) + 1;
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} else { /* high DMA controller */
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ffport = DMA2_FFC;
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waport = DMA2_CHN(chan - 4) + 2;
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}
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s = splhigh(); /* no interrupts Mr Jones! */
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outb(ffport, 0); /* clear register LSB flipflop */
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low1 = inb(waport);
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high1 = inb(waport);
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outb(ffport, 0); /* clear again */
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low2 = inb(waport);
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high2 = inb(waport);
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splx(s); /* enable interrupts again */
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/*
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* Now decide if a wrap has tried to skew our results.
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* Note that after TC, the count will read 0xffff, while we want
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* to return zero, so we add and then mask to compensate.
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*/
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if (low1 >= low2) {
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cnt = (low1 + (high1 << 8) + 1) & 0xffff;
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} else {
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cnt = (low2 + (high2 << 8) + 1) & 0xffff;
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}
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if (chan >= 4) /* high channels move words */
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cnt *= 2;
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return(cnt);
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}
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/*
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* Reached terminal count yet ?
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*/
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int
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isa_dmatc(int chan)
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{
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if (chan < 4)
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return(inb(DMA1_STATUS) & (1 << chan));
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else
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return(inb(DMA2_STATUS) & (1 << (chan & 3)));
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}
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/*
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* Stop a DMA transfer currently in progress.
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*/
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int
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isa_dmastop(int chan)
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{
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if ((dma_inuse & (1 << chan)) == 0)
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printf("isa_dmastop: channel %d not acquired\n", chan);
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if (((dma_busy & (1 << chan)) == 0) &&
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((dma_auto_mode & (1 << chan)) == 0)) {
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printf("chan %d not busy\n", chan);
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return -2 ;
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}
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if ((chan & 4) == 0) {
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outb(DMA1_SMSK, (chan & 3) | 4 /* disable mask */);
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} else {
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outb(DMA2_SMSK, (chan & 3) | 4 /* disable mask */);
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|
}
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|
return(isa_dmastatus(chan));
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}
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