2 * Copyright (c) 1991 The Regents of the University of California.
5 * This code is derived from software contributed to Berkeley by
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * from: @(#)isa.c 7.2 (Berkeley) 5/13/91
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
39 * code to manage AT bus
41 * 92/08/18 Frank P. MacLachlan (fpm@crash.cts.com):
42 * Fixed uninitialized variable problem and added code to deal
43 * with DMA page boundaries in isa_dmarangecheck(). Fixed word
44 * mode DMA count compution and reorganized DMA setup code in
48 #include <sys/param.h>
49 #include <sys/systm.h>
51 #include <sys/kernel.h>
52 #include <sys/malloc.h>
55 #include <sys/mutex.h>
56 #include <sys/module.h>
58 #include <vm/vm_param.h>
60 #include <isa/isareg.h>
61 #include <isa/isavar.h>
62 #include <isa/isa_dmareg.h>
64 #define ISARAM_END RAM_END
66 static int isa_dmarangecheck(caddr_t va, u_int length, int chan);
68 static caddr_t dma_bouncebuf[8];
69 static u_int dma_bouncebufsize[8];
70 static u_int8_t dma_bounced = 0;
71 static u_int8_t dma_busy = 0; /* Used in isa_dmastart() */
72 static u_int8_t dma_inuse = 0; /* User for acquire/release */
73 static u_int8_t dma_auto_mode = 0;
74 static struct mtx isa_dma_lock;
75 MTX_SYSINIT(isa_dma_lock, &isa_dma_lock, "isa DMA lock", MTX_DEF);
77 #define VALID_DMA_MASK (7)
79 /* high byte of address is stored in this port for i-th dma channel */
80 static int dmapageport[8] = { 0x87, 0x83, 0x81, 0x82, 0x8f, 0x8b, 0x89, 0x8a };
83 * Setup a DMA channel's bounce buffer.
86 isa_dma_init(int chan, u_int bouncebufsize, int flag)
92 if (chan & ~VALID_DMA_MASK)
93 panic("isa_dma_init: channel out of range");
97 /* Try malloc() first. It works better if it works. */
98 buf = malloc(bouncebufsize, M_DEVBUF, flag);
100 if (isa_dmarangecheck(buf, bouncebufsize, chan) != 0) {
108 buf = contigmalloc(bouncebufsize, M_DEVBUF, flag, 0ul, 0xfffffful,
109 1ul, chan & 4 ? 0x20000ul : 0x10000ul);
116 mtx_lock(&isa_dma_lock);
118 * If a DMA channel is shared, both drivers have to call isa_dma_init
119 * since they don't know that the other driver will do it.
120 * Just return if we're already set up good.
121 * XXX: this only works if they agree on the bouncebuf size. This
122 * XXX: is typically the case since they are multiple instances of
123 * XXX: the same driver.
125 if (dma_bouncebuf[chan] != NULL) {
127 contigfree(buf, bouncebufsize, M_DEVBUF);
130 mtx_unlock(&isa_dma_lock);
134 dma_bouncebufsize[chan] = bouncebufsize;
135 dma_bouncebuf[chan] = buf;
137 mtx_unlock(&isa_dma_lock);
143 * Register a DMA channel's usage. Usually called from a device driver
144 * in open() or during its initialization.
147 isa_dma_acquire(chan)
151 if (chan & ~VALID_DMA_MASK)
152 panic("isa_dma_acquire: channel out of range");
155 mtx_lock(&isa_dma_lock);
156 if (dma_inuse & (1 << chan)) {
157 printf("isa_dma_acquire: channel %d already in use\n", chan);
158 mtx_unlock(&isa_dma_lock);
161 dma_inuse |= (1 << chan);
162 dma_auto_mode &= ~(1 << chan);
163 mtx_unlock(&isa_dma_lock);
169 * Unregister a DMA channel's usage. Usually called from a device driver
170 * during close() or during its shutdown.
173 isa_dma_release(chan)
177 if (chan & ~VALID_DMA_MASK)
178 panic("isa_dma_release: channel out of range");
180 mtx_lock(&isa_dma_lock);
181 if ((dma_inuse & (1 << chan)) == 0)
182 printf("isa_dma_release: channel %d not in use\n", chan);
184 mtx_lock(&isa_dma_lock);
187 if (dma_busy & (1 << chan)) {
188 dma_busy &= ~(1 << chan);
190 * XXX We should also do "dma_bounced &= (1 << chan);"
191 * because we are acting on behalf of isa_dmadone() which
192 * was not called to end the last DMA operation. This does
193 * not matter now, but it may in the future.
197 dma_inuse &= ~(1 << chan);
198 dma_auto_mode &= ~(1 << chan);
200 mtx_unlock(&isa_dma_lock);
204 * isa_dmacascade(): program 8237 DMA controller channel to accept
205 * external dma control by a board.
212 if (chan & ~VALID_DMA_MASK)
213 panic("isa_dmacascade: channel out of range");
216 mtx_lock(&isa_dma_lock);
217 /* set dma channel mode, and set dma channel mode */
218 if ((chan & 4) == 0) {
219 outb(DMA1_MODE, DMA37MD_CASCADE | chan);
220 outb(DMA1_SMSK, chan);
222 outb(DMA2_MODE, DMA37MD_CASCADE | (chan & 3));
223 outb(DMA2_SMSK, chan & 3);
225 mtx_unlock(&isa_dma_lock);
229 * isa_dmastart(): program 8237 DMA controller channel, avoid page alignment
230 * problems by using a bounce buffer.
233 isa_dmastart(int flags, caddr_t addr, u_int nbytes, int chan)
238 int dma_range_checked;
240 dma_range_checked = isa_dmarangecheck(addr, nbytes, chan);
243 if (chan & ~VALID_DMA_MASK)
244 panic("isa_dmastart: channel out of range");
246 if ((chan < 4 && nbytes > (1<<16))
247 || (chan >= 4 && (nbytes > (1<<17) || (uintptr_t)addr & 1)))
248 panic("isa_dmastart: impossible request");
250 mtx_lock(&isa_dma_lock);
251 if ((dma_inuse & (1 << chan)) == 0)
252 printf("isa_dmastart: channel %d not acquired\n", chan);
254 mtx_lock(&isa_dma_lock);
259 * XXX This should be checked, but drivers like ad1848 only call
260 * isa_dmastart() once because they use Auto DMA mode. If we
261 * leave this in, drivers that do this will print this continuously.
263 if (dma_busy & (1 << chan))
264 printf("isa_dmastart: channel %d busy\n", chan);
267 dma_busy |= (1 << chan);
269 if (dma_range_checked) {
270 if (dma_bouncebuf[chan] == NULL
271 || dma_bouncebufsize[chan] < nbytes)
272 panic("isa_dmastart: bad bounce buffer");
273 dma_bounced |= (1 << chan);
274 newaddr = dma_bouncebuf[chan];
276 /* copy bounce buffer on write */
277 if (!(flags & ISADMA_READ))
278 bcopy(addr, newaddr, nbytes);
282 /* translate to physical */
283 phys = pmap_extract(kernel_pmap, (vm_offset_t)addr);
285 if (flags & ISADMA_RAW) {
286 dma_auto_mode |= (1 << chan);
288 dma_auto_mode &= ~(1 << chan);
291 if ((chan & 4) == 0) {
293 * Program one of DMA channels 0..3. These are
294 * byte mode channels.
296 /* set dma channel mode, and reset address ff */
298 /* If ISADMA_RAW flag is set, then use autoinitialise mode */
299 if (flags & ISADMA_RAW) {
300 if (flags & ISADMA_READ)
301 outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_WRITE|chan);
303 outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_READ|chan);
306 if (flags & ISADMA_READ)
307 outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|chan);
309 outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_READ|chan);
312 /* send start address */
313 waport = DMA1_CHN(chan);
315 outb(waport, phys>>8);
316 outb(dmapageport[chan], phys>>16);
319 outb(waport + 1, --nbytes);
320 outb(waport + 1, nbytes>>8);
323 outb(DMA1_SMSK, chan);
326 * Program one of DMA channels 4..7. These are
327 * word mode channels.
329 /* set dma channel mode, and reset address ff */
331 /* If ISADMA_RAW flag is set, then use autoinitialise mode */
332 if (flags & ISADMA_RAW) {
333 if (flags & ISADMA_READ)
334 outb(DMA2_MODE, DMA37MD_AUTO|DMA37MD_WRITE|(chan&3));
336 outb(DMA2_MODE, DMA37MD_AUTO|DMA37MD_READ|(chan&3));
339 if (flags & ISADMA_READ)
340 outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|(chan&3));
342 outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_READ|(chan&3));
345 /* send start address */
346 waport = DMA2_CHN(chan - 4);
347 outb(waport, phys>>1);
348 outb(waport, phys>>9);
349 outb(dmapageport[chan], phys>>16);
353 outb(waport + 2, --nbytes);
354 outb(waport + 2, nbytes>>8);
357 outb(DMA2_SMSK, chan & 3);
359 mtx_unlock(&isa_dma_lock);
363 isa_dmadone(int flags, caddr_t addr, int nbytes, int chan)
366 if (chan & ~VALID_DMA_MASK)
367 panic("isa_dmadone: channel out of range");
369 if ((dma_inuse & (1 << chan)) == 0)
370 printf("isa_dmadone: channel %d not acquired\n", chan);
373 mtx_lock(&isa_dma_lock);
374 if (((dma_busy & (1 << chan)) == 0) &&
375 (dma_auto_mode & (1 << chan)) == 0 )
376 printf("isa_dmadone: channel %d not busy\n", chan);
378 if ((dma_auto_mode & (1 << chan)) == 0)
379 outb(chan & 4 ? DMA2_SMSK : DMA1_SMSK, (chan & 3) | 4);
381 if (dma_bounced & (1 << chan)) {
382 /* copy bounce buffer on read */
383 if (flags & ISADMA_READ)
384 bcopy(dma_bouncebuf[chan], addr, nbytes);
386 dma_bounced &= ~(1 << chan);
388 dma_busy &= ~(1 << chan);
389 mtx_unlock(&isa_dma_lock);
393 * Check for problems with the address range of a DMA transfer
394 * (non-contiguous physical pages, outside of bus address space,
395 * crossing DMA page boundaries).
396 * Return true if special handling needed.
400 isa_dmarangecheck(caddr_t va, u_int length, int chan)
402 vm_paddr_t phys, priorpage = 0;
404 u_int dma_pgmsk = (chan & 4) ? ~(128*1024-1) : ~(64*1024-1);
406 endva = (vm_offset_t)round_page((vm_offset_t)va + length);
407 for (; va < (caddr_t) endva ; va += PAGE_SIZE) {
408 phys = trunc_page(pmap_extract(kernel_pmap, (vm_offset_t)va));
410 panic("isa_dmacheck: no physical page present");
411 if (phys >= ISARAM_END)
414 if (priorpage + PAGE_SIZE != phys)
416 /* check if crossing a DMA page boundary */
417 if (((u_int)priorpage ^ (u_int)phys) & dma_pgmsk)
426 * Query the progress of a transfer on a DMA channel.
428 * To avoid having to interrupt a transfer in progress, we sample
429 * each of the high and low databytes twice, and apply the following
430 * logic to determine the correct count.
432 * Reads are performed with interrupts disabled, thus it is to be
433 * expected that the time between reads is very small. At most
434 * one rollover in the low count byte can be expected within the
435 * four reads that are performed.
437 * There are three gaps in which a rollover can occur :
447 * If a rollover occurs in gap1 or gap2, the low2 value will be
448 * greater than the low1 value. In this case, low2 and high2 are a
449 * corresponding pair.
451 * In any other case, low1 and high1 can be considered to be correct.
453 * The function returns the number of bytes remaining in the transfer,
454 * or -1 if the channel requested is not active.
458 isa_dmastatus_locked(int chan)
462 u_long low1, high1, low2, high2;
464 mtx_assert(&isa_dma_lock, MA_OWNED);
466 /* channel active? */
467 if ((dma_inuse & (1 << chan)) == 0) {
468 printf("isa_dmastatus: channel %d not active\n", chan);
473 if (((dma_busy & (1 << chan)) == 0) &&
474 (dma_auto_mode & (1 << chan)) == 0 ) {
475 printf("chan %d not busy\n", chan);
478 if (chan < 4) { /* low DMA controller */
480 waport = DMA1_CHN(chan) + 1;
481 } else { /* high DMA controller */
483 waport = DMA2_CHN(chan - 4) + 2;
486 disable_intr(); /* no interrupts Mr Jones! */
487 outb(ffport, 0); /* clear register LSB flipflop */
490 outb(ffport, 0); /* clear again */
493 enable_intr(); /* enable interrupts again */
496 * Now decide if a wrap has tried to skew our results.
497 * Note that after TC, the count will read 0xffff, while we want
498 * to return zero, so we add and then mask to compensate.
501 cnt = (low1 + (high1 << 8) + 1) & 0xffff;
503 cnt = (low2 + (high2 << 8) + 1) & 0xffff;
506 if (chan >= 4) /* high channels move words */
512 isa_dmastatus(int chan)
516 mtx_lock(&isa_dma_lock);
517 status = isa_dmastatus_locked(chan);
518 mtx_unlock(&isa_dma_lock);
524 * Reached terminal count yet ?
531 return(inb(DMA1_STATUS) & (1 << chan));
533 return(inb(DMA2_STATUS) & (1 << (chan & 3)));
537 * Stop a DMA transfer currently in progress.
540 isa_dmastop(int chan)
544 mtx_lock(&isa_dma_lock);
545 if ((dma_inuse & (1 << chan)) == 0)
546 printf("isa_dmastop: channel %d not acquired\n", chan);
548 if (((dma_busy & (1 << chan)) == 0) &&
549 ((dma_auto_mode & (1 << chan)) == 0)) {
550 printf("chan %d not busy\n", chan);
551 mtx_unlock(&isa_dma_lock);
555 if ((chan & 4) == 0) {
556 outb(DMA1_SMSK, (chan & 3) | 4 /* disable mask */);
558 outb(DMA2_SMSK, (chan & 3) | 4 /* disable mask */);
561 status = isa_dmastatus_locked(chan);
563 mtx_unlock(&isa_dma_lock);
569 * Attach to the ISA PnP descriptor for the AT DMA controller
571 static struct isa_pnp_id atdma_ids[] = {
572 { 0x0002d041 /* PNP0200 */, "AT DMA controller" },
577 atdma_probe(device_t dev)
581 if ((result = ISA_PNP_PROBE(device_get_parent(dev), dev, atdma_ids)) <= 0)
587 atdma_attach(device_t dev)
592 static device_method_t atdma_methods[] = {
593 /* Device interface */
594 DEVMETHOD(device_probe, atdma_probe),
595 DEVMETHOD(device_attach, atdma_attach),
596 DEVMETHOD(device_detach, bus_generic_detach),
597 DEVMETHOD(device_shutdown, bus_generic_shutdown),
598 DEVMETHOD(device_suspend, bus_generic_suspend),
599 DEVMETHOD(device_resume, bus_generic_resume),
603 static driver_t atdma_driver = {
609 static devclass_t atdma_devclass;
611 DRIVER_MODULE(atdma, isa, atdma_driver, atdma_devclass, 0, 0);
612 DRIVER_MODULE(atdma, acpi, atdma_driver, atdma_devclass, 0, 0);