au1x00.c 19.5 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734
/*
 * BRIEF MODULE DESCRIPTION
 *  Driver for AMD Au1000 MIPS Processor, AC'97 Sound Port
 *
 * Copyright 2004 Cooper Street Innovations Inc.
 * Author: Charles Eidsness	<charles@cooper-street.com>
 *
 *  This program is free software; you can redistribute  it and/or modify it
 *  under  the terms of  the GNU General  Public License as published by the
 *  Free Software Foundation;  either version 2 of the  License, or (at your
 *  option) any later version.
 *
 *  THIS  SOFTWARE  IS PROVIDED   ``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 AUTHOR  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.
 *
 *  You should have received a copy of the  GNU General Public License along
 *  with this program; if not, write  to the Free Software Foundation, Inc.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * History:
 *
 * 2004-09-09 Charles Eidsness	-- Original verion -- based on
 * 				  sa11xx-uda1341.c ALSA driver and the
 *				  au1000.c OSS driver.
 * 2004-09-09 Matt Porter	-- Added support for ALSA 1.0.6
 *
 */

#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <sound/core.h>
#include <sound/initval.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/ac97_codec.h>
#include <asm/mach-au1x00/au1000.h>
#include <asm/mach-au1x00/au1000_dma.h>

MODULE_AUTHOR("Charles Eidsness <charles@cooper-street.com>");
MODULE_DESCRIPTION("Au1000 AC'97 ALSA Driver");
MODULE_LICENSE("GPL");
MODULE_SUPPORTED_DEVICE("{{AMD,Au1000 AC'97}}");

#define PLAYBACK 0
#define CAPTURE 1
#define AC97_SLOT_3 0x01
#define AC97_SLOT_4 0x02
#define AC97_SLOT_6 0x08
#define AC97_CMD_IRQ 31
#define READ 0
#define WRITE 1
#define READ_WAIT 2
#define RW_DONE 3

struct au1000_period
{
	u32 start;
	u32 relative_end;	/*realtive to start of buffer*/
	struct au1000_period * next;
};

/*Au1000 AC97 Port Control Reisters*/
struct au1000_ac97_reg {
	u32 volatile config;
	u32 volatile status;
	u32 volatile data;
	u32 volatile cmd;
	u32 volatile cntrl;
};

struct audio_stream {
	struct snd_pcm_substream *substream;
	int dma;
	spinlock_t dma_lock;
	struct au1000_period * buffer;
	unsigned int period_size;
	unsigned int periods;
};

struct snd_au1000 {
	struct snd_card *card;
	struct au1000_ac97_reg volatile *ac97_ioport;

	struct resource *ac97_res_port;
	spinlock_t ac97_lock;
	struct snd_ac97 *ac97;

	struct snd_pcm *pcm;
	struct audio_stream *stream[2];	/* playback & capture */
	int dmaid[2];		/* tx(0)/rx(1) DMA ids */
};

/*--------------------------- Local Functions --------------------------------*/
static void
au1000_set_ac97_xmit_slots(struct snd_au1000 *au1000, long xmit_slots)
{
	u32 volatile ac97_config;

	spin_lock(&au1000->ac97_lock);
	ac97_config = au1000->ac97_ioport->config;
	ac97_config = ac97_config & ~AC97C_XMIT_SLOTS_MASK;
	ac97_config |= (xmit_slots << AC97C_XMIT_SLOTS_BIT);
	au1000->ac97_ioport->config = ac97_config;
	spin_unlock(&au1000->ac97_lock);
}

static void
au1000_set_ac97_recv_slots(struct snd_au1000 *au1000, long recv_slots)
{
	u32 volatile ac97_config;

	spin_lock(&au1000->ac97_lock);
	ac97_config = au1000->ac97_ioport->config;
	ac97_config = ac97_config & ~AC97C_RECV_SLOTS_MASK;
	ac97_config |= (recv_slots << AC97C_RECV_SLOTS_BIT);
	au1000->ac97_ioport->config = ac97_config;
	spin_unlock(&au1000->ac97_lock);
}


static void
au1000_release_dma_link(struct audio_stream *stream)
{
	struct au1000_period * pointer;
	struct au1000_period * pointer_next;

	stream->period_size = 0;
	stream->periods = 0;
	pointer = stream->buffer;
	if (! pointer)
		return;
	do {
		pointer_next = pointer->next;
		kfree(pointer);
		pointer = pointer_next;
	} while (pointer != stream->buffer);
	stream->buffer = NULL;
}

static int
au1000_setup_dma_link(struct audio_stream *stream, unsigned int period_bytes,
		      unsigned int periods)
{
	struct snd_pcm_substream *substream = stream->substream;
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct au1000_period *pointer;
	unsigned long dma_start;
	int i;

	dma_start = virt_to_phys(runtime->dma_area);

	if (stream->period_size == period_bytes &&
	    stream->periods == periods)
		return 0; /* not changed */

	au1000_release_dma_link(stream);

	stream->period_size = period_bytes;
	stream->periods = periods;

	stream->buffer = kmalloc(sizeof(struct au1000_period), GFP_KERNEL);
	if (! stream->buffer)
		return -ENOMEM;
	pointer = stream->buffer;
	for (i = 0; i < periods; i++) {
		pointer->start = (u32)(dma_start + (i * period_bytes));
		pointer->relative_end = (u32) (((i+1) * period_bytes) - 0x1);
		if (i < periods - 1) {
			pointer->next = kmalloc(sizeof(struct au1000_period), GFP_KERNEL);
			if (! pointer->next) {
				au1000_release_dma_link(stream);
				return -ENOMEM;
			}
			pointer = pointer->next;
		}
	}
	pointer->next = stream->buffer;
	return 0;
}

static void
au1000_dma_stop(struct audio_stream *stream)
{
	if (snd_BUG_ON(!stream->buffer))
		return;
	disable_dma(stream->dma);
}

static void
au1000_dma_start(struct audio_stream *stream)
{
	if (snd_BUG_ON(!stream->buffer))
		return;

	init_dma(stream->dma);
	if (get_dma_active_buffer(stream->dma) == 0) {
		clear_dma_done0(stream->dma);
		set_dma_addr0(stream->dma, stream->buffer->start);
		set_dma_count0(stream->dma, stream->period_size >> 1);
		set_dma_addr1(stream->dma, stream->buffer->next->start);
		set_dma_count1(stream->dma, stream->period_size >> 1);
	} else {
		clear_dma_done1(stream->dma);
		set_dma_addr1(stream->dma, stream->buffer->start);
		set_dma_count1(stream->dma, stream->period_size >> 1);
		set_dma_addr0(stream->dma, stream->buffer->next->start);
		set_dma_count0(stream->dma, stream->period_size >> 1);
	}
	enable_dma_buffers(stream->dma);
	start_dma(stream->dma);
}

static irqreturn_t
au1000_dma_interrupt(int irq, void *dev_id)
{
	struct audio_stream *stream = (struct audio_stream *) dev_id;
	struct snd_pcm_substream *substream = stream->substream;

	spin_lock(&stream->dma_lock);
	switch (get_dma_buffer_done(stream->dma)) {
	case DMA_D0:
		stream->buffer = stream->buffer->next;
		clear_dma_done0(stream->dma);
		set_dma_addr0(stream->dma, stream->buffer->next->start);
		set_dma_count0(stream->dma, stream->period_size >> 1);
		enable_dma_buffer0(stream->dma);
		break;
	case DMA_D1:
		stream->buffer = stream->buffer->next;
		clear_dma_done1(stream->dma);
		set_dma_addr1(stream->dma, stream->buffer->next->start);
		set_dma_count1(stream->dma, stream->period_size >> 1);
		enable_dma_buffer1(stream->dma);
		break;
	case (DMA_D0 | DMA_D1):
		printk(KERN_ERR "DMA %d missed interrupt.\n",stream->dma);
		au1000_dma_stop(stream);
		au1000_dma_start(stream);
		break;
	case (~DMA_D0 & ~DMA_D1):
		printk(KERN_ERR "DMA %d empty irq.\n",stream->dma);
	}
	spin_unlock(&stream->dma_lock);
	snd_pcm_period_elapsed(substream);
	return IRQ_HANDLED;
}

/*-------------------------- PCM Audio Streams -------------------------------*/

static unsigned int rates[] = {8000, 11025, 16000, 22050};
static struct snd_pcm_hw_constraint_list hw_constraints_rates = {
	.count	= ARRAY_SIZE(rates),
	.list	= rates,
	.mask	= 0,
};

static struct snd_pcm_hardware snd_au1000_hw =
{
	.info			= (SNDRV_PCM_INFO_INTERLEAVED | \
				SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID),
	.formats		= SNDRV_PCM_FMTBIT_S16_LE,
	.rates			= (SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_11025 |
				SNDRV_PCM_RATE_16000 | SNDRV_PCM_RATE_22050),
	.rate_min		= 8000,
	.rate_max		= 22050,
	.channels_min		= 1,
	.channels_max		= 2,
	.buffer_bytes_max	= 128*1024,
	.period_bytes_min	= 32,
	.period_bytes_max	= 16*1024,
	.periods_min		= 8,
	.periods_max		= 255,
	.fifo_size		= 16,
};

static int
snd_au1000_playback_open(struct snd_pcm_substream *substream)
{
	struct snd_au1000 *au1000 = substream->pcm->private_data;

	au1000->stream[PLAYBACK]->substream = substream;
	au1000->stream[PLAYBACK]->buffer = NULL;
	substream->private_data = au1000->stream[PLAYBACK];
	substream->runtime->hw = snd_au1000_hw;
	return (snd_pcm_hw_constraint_list(substream->runtime, 0,
		SNDRV_PCM_HW_PARAM_RATE, &hw_constraints_rates) < 0);
}

static int
snd_au1000_capture_open(struct snd_pcm_substream *substream)
{
	struct snd_au1000 *au1000 = substream->pcm->private_data;

	au1000->stream[CAPTURE]->substream = substream;
	au1000->stream[CAPTURE]->buffer = NULL;
	substream->private_data = au1000->stream[CAPTURE];
	substream->runtime->hw = snd_au1000_hw;
	return (snd_pcm_hw_constraint_list(substream->runtime, 0,
		SNDRV_PCM_HW_PARAM_RATE, &hw_constraints_rates) < 0);
}

static int
snd_au1000_playback_close(struct snd_pcm_substream *substream)
{
	struct snd_au1000 *au1000 = substream->pcm->private_data;

	au1000->stream[PLAYBACK]->substream = NULL;
	return 0;
}

static int
snd_au1000_capture_close(struct snd_pcm_substream *substream)
{
	struct snd_au1000 *au1000 = substream->pcm->private_data;

	au1000->stream[CAPTURE]->substream = NULL;
	return 0;
}

static int
snd_au1000_hw_params(struct snd_pcm_substream *substream,
					struct snd_pcm_hw_params *hw_params)
{
	struct audio_stream *stream = substream->private_data;
	int err;

	err = snd_pcm_lib_malloc_pages(substream,
				       params_buffer_bytes(hw_params));
	if (err < 0)
		return err;
	return au1000_setup_dma_link(stream,
				     params_period_bytes(hw_params),
				     params_periods(hw_params));
}

static int
snd_au1000_hw_free(struct snd_pcm_substream *substream)
{
	struct audio_stream *stream = substream->private_data;
	au1000_release_dma_link(stream);
	return snd_pcm_lib_free_pages(substream);
}

static int
snd_au1000_playback_prepare(struct snd_pcm_substream *substream)
{
	struct snd_au1000 *au1000 = substream->pcm->private_data;
	struct snd_pcm_runtime *runtime = substream->runtime;

	if (runtime->channels == 1)
		au1000_set_ac97_xmit_slots(au1000, AC97_SLOT_4);
	else
		au1000_set_ac97_xmit_slots(au1000, AC97_SLOT_3 | AC97_SLOT_4);
	snd_ac97_set_rate(au1000->ac97, AC97_PCM_FRONT_DAC_RATE, runtime->rate);
	return 0;
}

static int
snd_au1000_capture_prepare(struct snd_pcm_substream *substream)
{
	struct snd_au1000 *au1000 = substream->pcm->private_data;
	struct snd_pcm_runtime *runtime = substream->runtime;

	if (runtime->channels == 1)
		au1000_set_ac97_recv_slots(au1000, AC97_SLOT_4);
	else
		au1000_set_ac97_recv_slots(au1000, AC97_SLOT_3 | AC97_SLOT_4);
	snd_ac97_set_rate(au1000->ac97, AC97_PCM_LR_ADC_RATE, runtime->rate);
	return 0;
}

static int
snd_au1000_trigger(struct snd_pcm_substream *substream, int cmd)
{
	struct audio_stream *stream = substream->private_data;
	int err = 0;

	spin_lock(&stream->dma_lock);
	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
		au1000_dma_start(stream);
		break;
	case SNDRV_PCM_TRIGGER_STOP:
		au1000_dma_stop(stream);
		break;
	default:
		err = -EINVAL;
		break;
	}
	spin_unlock(&stream->dma_lock);
	return err;
}

static snd_pcm_uframes_t
snd_au1000_pointer(struct snd_pcm_substream *substream)
{
	struct audio_stream *stream = substream->private_data;
	struct snd_pcm_runtime *runtime = substream->runtime;
	long location;

	spin_lock(&stream->dma_lock);
	location = get_dma_residue(stream->dma);
	spin_unlock(&stream->dma_lock);
	location = stream->buffer->relative_end - location;
	if (location == -1)
		location = 0;
	return bytes_to_frames(runtime,location);
}

static struct snd_pcm_ops snd_card_au1000_playback_ops = {
	.open			= snd_au1000_playback_open,
	.close			= snd_au1000_playback_close,
	.ioctl			= snd_pcm_lib_ioctl,
	.hw_params	        = snd_au1000_hw_params,
	.hw_free	        = snd_au1000_hw_free,
	.prepare		= snd_au1000_playback_prepare,
	.trigger		= snd_au1000_trigger,
	.pointer		= snd_au1000_pointer,
};

static struct snd_pcm_ops snd_card_au1000_capture_ops = {
	.open			= snd_au1000_capture_open,
	.close			= snd_au1000_capture_close,
	.ioctl			= snd_pcm_lib_ioctl,
	.hw_params	        = snd_au1000_hw_params,
	.hw_free	        = snd_au1000_hw_free,
	.prepare		= snd_au1000_capture_prepare,
	.trigger		= snd_au1000_trigger,
	.pointer		= snd_au1000_pointer,
};

static int
snd_au1000_pcm_new(struct snd_au1000 *au1000)
{
	struct snd_pcm *pcm;
	int err;
	unsigned long flags;

	if ((err = snd_pcm_new(au1000->card, "AU1000 AC97 PCM", 0, 1, 1, &pcm)) < 0)
		return err;

	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
		snd_dma_continuous_data(GFP_KERNEL), 128*1024, 128*1024);

	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK,
		&snd_card_au1000_playback_ops);
	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE,
		&snd_card_au1000_capture_ops);

	pcm->private_data = au1000;
	pcm->info_flags = 0;
	strcpy(pcm->name, "Au1000 AC97 PCM");

	spin_lock_init(&au1000->stream[PLAYBACK]->dma_lock);
	spin_lock_init(&au1000->stream[CAPTURE]->dma_lock);

	flags = claim_dma_lock();
	au1000->stream[PLAYBACK]->dma = request_au1000_dma(au1000->dmaid[0],
			"AC97 TX", au1000_dma_interrupt, 0,
			au1000->stream[PLAYBACK]);
	if (au1000->stream[PLAYBACK]->dma < 0) {
		release_dma_lock(flags);
		return -EBUSY;
	}
	au1000->stream[CAPTURE]->dma = request_au1000_dma(au1000->dmaid[1],
			"AC97 RX", au1000_dma_interrupt, 0,
			au1000->stream[CAPTURE]);
	if (au1000->stream[CAPTURE]->dma < 0){
		release_dma_lock(flags);
		return -EBUSY;
	}
	/* enable DMA coherency in read/write DMA channels */
	set_dma_mode(au1000->stream[PLAYBACK]->dma,
		     get_dma_mode(au1000->stream[PLAYBACK]->dma) & ~DMA_NC);
	set_dma_mode(au1000->stream[CAPTURE]->dma,
		     get_dma_mode(au1000->stream[CAPTURE]->dma) & ~DMA_NC);
	release_dma_lock(flags);
	au1000->pcm = pcm;
	return 0;
}


/*-------------------------- AC97 CODEC Control ------------------------------*/

static unsigned short
snd_au1000_ac97_read(struct snd_ac97 *ac97, unsigned short reg)
{
	struct snd_au1000 *au1000 = ac97->private_data;
	u32 volatile cmd;
	u16 volatile data;
	int             i;

	spin_lock(&au1000->ac97_lock);
/* would rather use the interrupt than this polling but it works and I can't
get the interrupt driven case to work efficiently */
	for (i = 0; i < 0x5000; i++)
		if (!(au1000->ac97_ioport->status & AC97C_CP))
			break;
	if (i == 0x5000)
		printk(KERN_ERR "au1000 AC97: AC97 command read timeout\n");

	cmd = (u32) reg & AC97C_INDEX_MASK;
	cmd |= AC97C_READ;
	au1000->ac97_ioport->cmd = cmd;

	/* now wait for the data */
	for (i = 0; i < 0x5000; i++)
		if (!(au1000->ac97_ioport->status & AC97C_CP))
			break;
	if (i == 0x5000) {
		printk(KERN_ERR "au1000 AC97: AC97 command read timeout\n");
		spin_unlock(&au1000->ac97_lock);
		return 0;
	}

	data = au1000->ac97_ioport->cmd & 0xffff;
	spin_unlock(&au1000->ac97_lock);

	return data;

}


static void
snd_au1000_ac97_write(struct snd_ac97 *ac97, unsigned short reg, unsigned short val)
{
	struct snd_au1000 *au1000 = ac97->private_data;
	u32 cmd;
	int i;

	spin_lock(&au1000->ac97_lock);
/* would rather use the interrupt than this polling but it works and I can't
get the interrupt driven case to work efficiently */
	for (i = 0; i < 0x5000; i++)
		if (!(au1000->ac97_ioport->status & AC97C_CP))
			break;
	if (i == 0x5000)
		printk(KERN_ERR "au1000 AC97: AC97 command write timeout\n");

	cmd = (u32) reg & AC97C_INDEX_MASK;
	cmd &= ~AC97C_READ;
	cmd |= ((u32) val << AC97C_WD_BIT);
	au1000->ac97_ioport->cmd = cmd;
	spin_unlock(&au1000->ac97_lock);
}

/*------------------------------ Setup / Destroy ----------------------------*/

static void snd_au1000_free(struct snd_card *card)
{
	struct snd_au1000 *au1000 = card->private_data;

	if (au1000->stream[PLAYBACK]) {
	  	if (au1000->stream[PLAYBACK]->dma >= 0)
			free_au1000_dma(au1000->stream[PLAYBACK]->dma);
		kfree(au1000->stream[PLAYBACK]);
	}

	if (au1000->stream[CAPTURE]) {
		if (au1000->stream[CAPTURE]->dma >= 0)
			free_au1000_dma(au1000->stream[CAPTURE]->dma);
		kfree(au1000->stream[CAPTURE]);
	}

	if (au1000->ac97_res_port) {
		/* put internal AC97 block into reset */
		if (au1000->ac97_ioport) {
			au1000->ac97_ioport->cntrl = AC97C_RS;
			iounmap(au1000->ac97_ioport);
			au1000->ac97_ioport = NULL;
		}
		release_and_free_resource(au1000->ac97_res_port);
		au1000->ac97_res_port = NULL;
	}
}

static struct snd_ac97_bus_ops ops = {
	.write	= snd_au1000_ac97_write,
	.read	= snd_au1000_ac97_read,
};

static int au1000_ac97_probe(struct platform_device *pdev)
{
	int err;
	void __iomem *io;
	struct resource *r;
	struct snd_card *card;
	struct snd_au1000 *au1000;
	struct snd_ac97_bus *pbus;
	struct snd_ac97_template ac97;

	err = snd_card_new(&pdev->dev, -1, "AC97", THIS_MODULE,
			   sizeof(struct snd_au1000), &card);
	if (err < 0)
		return err;

	au1000 = card->private_data;
	au1000->card = card;
	spin_lock_init(&au1000->ac97_lock);

	/* from here on let ALSA call the special freeing function */
	card->private_free = snd_au1000_free;

	/* TX DMA ID */
	r = platform_get_resource(pdev, IORESOURCE_DMA, 0);
	if (!r) {
		err = -ENODEV;
		snd_printk(KERN_INFO "no TX DMA platform resource!\n");
		goto out;
	}
	au1000->dmaid[0] = r->start;

	/* RX DMA ID */
	r = platform_get_resource(pdev, IORESOURCE_DMA, 1);
	if (!r) {
		err = -ENODEV;
		snd_printk(KERN_INFO "no RX DMA platform resource!\n");
		goto out;
	}
	au1000->dmaid[1] = r->start;

	au1000->stream[PLAYBACK] = kmalloc(sizeof(struct audio_stream),
					   GFP_KERNEL);
	if (!au1000->stream[PLAYBACK]) {
		err = -ENOMEM;
		goto out;
	}
	au1000->stream[PLAYBACK]->dma = -1;

	au1000->stream[CAPTURE] = kmalloc(sizeof(struct audio_stream),
					  GFP_KERNEL);
	if (!au1000->stream[CAPTURE]) {
		err = -ENOMEM;
		goto out;
	}
	au1000->stream[CAPTURE]->dma = -1;

	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!r) {
		err = -ENODEV;
		goto out;
	}

	err = -EBUSY;
	au1000->ac97_res_port = request_mem_region(r->start, resource_size(r),
						   pdev->name);
	if (!au1000->ac97_res_port) {
		snd_printk(KERN_ERR "ALSA AC97: can't grab AC97 port\n");
		goto out;
	}

	io = ioremap(r->start, resource_size(r));
	if (!io)
		goto out;

	au1000->ac97_ioport = (struct au1000_ac97_reg *)io;

	/* configure pins for AC'97
	TODO: move to board_setup.c */
	au_writel(au_readl(SYS_PINFUNC) & ~0x02, SYS_PINFUNC);

	/* Initialise Au1000's AC'97 Control Block */
	au1000->ac97_ioport->cntrl = AC97C_RS | AC97C_CE;
	udelay(10);
	au1000->ac97_ioport->cntrl = AC97C_CE;
	udelay(10);

	/* Initialise External CODEC -- cold reset */
	au1000->ac97_ioport->config = AC97C_RESET;
	udelay(10);
	au1000->ac97_ioport->config = 0x0;
	mdelay(5);

	/* Initialise AC97 middle-layer */
	err = snd_ac97_bus(au1000->card, 0, &ops, au1000, &pbus);
	if (err < 0)
		goto out;

	memset(&ac97, 0, sizeof(ac97));
	ac97.private_data = au1000;
	err = snd_ac97_mixer(pbus, &ac97, &au1000->ac97);
	if (err < 0)
		goto out;

	err = snd_au1000_pcm_new(au1000);
	if (err < 0)
		goto out;

	strcpy(card->driver, "Au1000-AC97");
	strcpy(card->shortname, "AMD Au1000-AC97");
	sprintf(card->longname, "AMD Au1000--AC97 ALSA Driver");

	err = snd_card_register(card);
	if (err < 0)
		goto out;

	printk(KERN_INFO "ALSA AC97: Driver Initialized\n");

	platform_set_drvdata(pdev, card);

	return 0;

 out:
	snd_card_free(card);
	return err;
}

static int au1000_ac97_remove(struct platform_device *pdev)
{
	return snd_card_free(platform_get_drvdata(pdev));
}

struct platform_driver au1000_ac97c_driver = {
	.driver	= {
		.name	= "au1000-ac97c",
		.owner	= THIS_MODULE,
	},
	.probe		= au1000_ac97_probe,
	.remove		= au1000_ac97_remove,
};

module_platform_driver(au1000_ac97c_driver);