xref: /openbmc/linux/sound/atmel/ac97c.c (revision b8bb76713ec50df2f11efee386e16f93d51e1076)
1 /*
2  * Driver for the Atmel AC97C controller
3  *
4  * Copyright (C) 2005-2009 Atmel Corporation
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License version 2 as published by
8  * the Free Software Foundation.
9  */
10 #include <linux/clk.h>
11 #include <linux/delay.h>
12 #include <linux/bitmap.h>
13 #include <linux/dmaengine.h>
14 #include <linux/dma-mapping.h>
15 #include <linux/init.h>
16 #include <linux/interrupt.h>
17 #include <linux/module.h>
18 #include <linux/platform_device.h>
19 #include <linux/mutex.h>
20 #include <linux/gpio.h>
21 #include <linux/io.h>
22 
23 #include <sound/core.h>
24 #include <sound/initval.h>
25 #include <sound/pcm.h>
26 #include <sound/pcm_params.h>
27 #include <sound/ac97_codec.h>
28 #include <sound/atmel-ac97c.h>
29 #include <sound/memalloc.h>
30 
31 #include <linux/dw_dmac.h>
32 
33 #include "ac97c.h"
34 
35 enum {
36 	DMA_TX_READY = 0,
37 	DMA_RX_READY,
38 	DMA_TX_CHAN_PRESENT,
39 	DMA_RX_CHAN_PRESENT,
40 };
41 
42 /* Serialize access to opened variable */
43 static DEFINE_MUTEX(opened_mutex);
44 
45 struct atmel_ac97c_dma {
46 	struct dma_chan			*rx_chan;
47 	struct dma_chan			*tx_chan;
48 };
49 
50 struct atmel_ac97c {
51 	struct clk			*pclk;
52 	struct platform_device		*pdev;
53 	struct atmel_ac97c_dma		dma;
54 
55 	struct snd_pcm_substream	*playback_substream;
56 	struct snd_pcm_substream	*capture_substream;
57 	struct snd_card			*card;
58 	struct snd_pcm			*pcm;
59 	struct snd_ac97			*ac97;
60 	struct snd_ac97_bus		*ac97_bus;
61 
62 	u64				cur_format;
63 	unsigned int			cur_rate;
64 	unsigned long			flags;
65 	/* Serialize access to opened variable */
66 	spinlock_t			lock;
67 	void __iomem			*regs;
68 	int				opened;
69 	int				reset_pin;
70 };
71 
72 #define get_chip(card) ((struct atmel_ac97c *)(card)->private_data)
73 
74 #define ac97c_writel(chip, reg, val)			\
75 	__raw_writel((val), (chip)->regs + AC97C_##reg)
76 #define ac97c_readl(chip, reg)				\
77 	__raw_readl((chip)->regs + AC97C_##reg)
78 
79 /* This function is called by the DMA driver. */
80 static void atmel_ac97c_dma_playback_period_done(void *arg)
81 {
82 	struct atmel_ac97c *chip = arg;
83 	snd_pcm_period_elapsed(chip->playback_substream);
84 }
85 
86 static void atmel_ac97c_dma_capture_period_done(void *arg)
87 {
88 	struct atmel_ac97c *chip = arg;
89 	snd_pcm_period_elapsed(chip->capture_substream);
90 }
91 
92 static int atmel_ac97c_prepare_dma(struct atmel_ac97c *chip,
93 		struct snd_pcm_substream *substream,
94 		enum dma_data_direction direction)
95 {
96 	struct dma_chan			*chan;
97 	struct dw_cyclic_desc		*cdesc;
98 	struct snd_pcm_runtime		*runtime = substream->runtime;
99 	unsigned long			buffer_len, period_len;
100 
101 	/*
102 	 * We don't do DMA on "complex" transfers, i.e. with
103 	 * non-halfword-aligned buffers or lengths.
104 	 */
105 	if (runtime->dma_addr & 1 || runtime->buffer_size & 1) {
106 		dev_dbg(&chip->pdev->dev, "too complex transfer\n");
107 		return -EINVAL;
108 	}
109 
110 	if (direction == DMA_TO_DEVICE)
111 		chan = chip->dma.tx_chan;
112 	else
113 		chan = chip->dma.rx_chan;
114 
115 	buffer_len = frames_to_bytes(runtime, runtime->buffer_size);
116 	period_len = frames_to_bytes(runtime, runtime->period_size);
117 
118 	cdesc = dw_dma_cyclic_prep(chan, runtime->dma_addr, buffer_len,
119 			period_len, direction);
120 	if (IS_ERR(cdesc)) {
121 		dev_dbg(&chip->pdev->dev, "could not prepare cyclic DMA\n");
122 		return PTR_ERR(cdesc);
123 	}
124 
125 	if (direction == DMA_TO_DEVICE) {
126 		cdesc->period_callback = atmel_ac97c_dma_playback_period_done;
127 		set_bit(DMA_TX_READY, &chip->flags);
128 	} else {
129 		cdesc->period_callback = atmel_ac97c_dma_capture_period_done;
130 		set_bit(DMA_RX_READY, &chip->flags);
131 	}
132 
133 	cdesc->period_callback_param = chip;
134 
135 	return 0;
136 }
137 
138 static struct snd_pcm_hardware atmel_ac97c_hw = {
139 	.info			= (SNDRV_PCM_INFO_MMAP
140 				  | SNDRV_PCM_INFO_MMAP_VALID
141 				  | SNDRV_PCM_INFO_INTERLEAVED
142 				  | SNDRV_PCM_INFO_BLOCK_TRANSFER
143 				  | SNDRV_PCM_INFO_JOINT_DUPLEX
144 				  | SNDRV_PCM_INFO_RESUME
145 				  | SNDRV_PCM_INFO_PAUSE),
146 	.formats		= (SNDRV_PCM_FMTBIT_S16_BE
147 				  | SNDRV_PCM_FMTBIT_S16_LE),
148 	.rates			= (SNDRV_PCM_RATE_CONTINUOUS),
149 	.rate_min		= 4000,
150 	.rate_max		= 48000,
151 	.channels_min		= 1,
152 	.channels_max		= 2,
153 	.buffer_bytes_max	= 64 * 4096,
154 	.period_bytes_min	= 4096,
155 	.period_bytes_max	= 4096,
156 	.periods_min		= 4,
157 	.periods_max		= 64,
158 };
159 
160 static int atmel_ac97c_playback_open(struct snd_pcm_substream *substream)
161 {
162 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
163 	struct snd_pcm_runtime *runtime = substream->runtime;
164 
165 	mutex_lock(&opened_mutex);
166 	chip->opened++;
167 	runtime->hw = atmel_ac97c_hw;
168 	if (chip->cur_rate) {
169 		runtime->hw.rate_min = chip->cur_rate;
170 		runtime->hw.rate_max = chip->cur_rate;
171 	}
172 	if (chip->cur_format)
173 		runtime->hw.formats = (1ULL << chip->cur_format);
174 	mutex_unlock(&opened_mutex);
175 	chip->playback_substream = substream;
176 	return 0;
177 }
178 
179 static int atmel_ac97c_capture_open(struct snd_pcm_substream *substream)
180 {
181 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
182 	struct snd_pcm_runtime *runtime = substream->runtime;
183 
184 	mutex_lock(&opened_mutex);
185 	chip->opened++;
186 	runtime->hw = atmel_ac97c_hw;
187 	if (chip->cur_rate) {
188 		runtime->hw.rate_min = chip->cur_rate;
189 		runtime->hw.rate_max = chip->cur_rate;
190 	}
191 	if (chip->cur_format)
192 		runtime->hw.formats = (1ULL << chip->cur_format);
193 	mutex_unlock(&opened_mutex);
194 	chip->capture_substream = substream;
195 	return 0;
196 }
197 
198 static int atmel_ac97c_playback_close(struct snd_pcm_substream *substream)
199 {
200 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
201 
202 	mutex_lock(&opened_mutex);
203 	chip->opened--;
204 	if (!chip->opened) {
205 		chip->cur_rate = 0;
206 		chip->cur_format = 0;
207 	}
208 	mutex_unlock(&opened_mutex);
209 
210 	chip->playback_substream = NULL;
211 
212 	return 0;
213 }
214 
215 static int atmel_ac97c_capture_close(struct snd_pcm_substream *substream)
216 {
217 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
218 
219 	mutex_lock(&opened_mutex);
220 	chip->opened--;
221 	if (!chip->opened) {
222 		chip->cur_rate = 0;
223 		chip->cur_format = 0;
224 	}
225 	mutex_unlock(&opened_mutex);
226 
227 	chip->capture_substream = NULL;
228 
229 	return 0;
230 }
231 
232 static int atmel_ac97c_playback_hw_params(struct snd_pcm_substream *substream,
233 		struct snd_pcm_hw_params *hw_params)
234 {
235 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
236 	int retval;
237 
238 	retval = snd_pcm_lib_malloc_pages(substream,
239 					params_buffer_bytes(hw_params));
240 	if (retval < 0)
241 		return retval;
242 	/* snd_pcm_lib_malloc_pages returns 1 if buffer is changed. */
243 	if (retval == 1)
244 		if (test_and_clear_bit(DMA_TX_READY, &chip->flags))
245 			dw_dma_cyclic_free(chip->dma.tx_chan);
246 
247 	/* Set restrictions to params. */
248 	mutex_lock(&opened_mutex);
249 	chip->cur_rate = params_rate(hw_params);
250 	chip->cur_format = params_format(hw_params);
251 	mutex_unlock(&opened_mutex);
252 
253 	return retval;
254 }
255 
256 static int atmel_ac97c_capture_hw_params(struct snd_pcm_substream *substream,
257 		struct snd_pcm_hw_params *hw_params)
258 {
259 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
260 	int retval;
261 
262 	retval = snd_pcm_lib_malloc_pages(substream,
263 					params_buffer_bytes(hw_params));
264 	if (retval < 0)
265 		return retval;
266 	/* snd_pcm_lib_malloc_pages returns 1 if buffer is changed. */
267 	if (retval == 1)
268 		if (test_and_clear_bit(DMA_RX_READY, &chip->flags))
269 			dw_dma_cyclic_free(chip->dma.rx_chan);
270 
271 	/* Set restrictions to params. */
272 	mutex_lock(&opened_mutex);
273 	chip->cur_rate = params_rate(hw_params);
274 	chip->cur_format = params_format(hw_params);
275 	mutex_unlock(&opened_mutex);
276 
277 	return retval;
278 }
279 
280 static int atmel_ac97c_playback_hw_free(struct snd_pcm_substream *substream)
281 {
282 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
283 	if (test_and_clear_bit(DMA_TX_READY, &chip->flags))
284 		dw_dma_cyclic_free(chip->dma.tx_chan);
285 	return snd_pcm_lib_free_pages(substream);
286 }
287 
288 static int atmel_ac97c_capture_hw_free(struct snd_pcm_substream *substream)
289 {
290 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
291 	if (test_and_clear_bit(DMA_RX_READY, &chip->flags))
292 		dw_dma_cyclic_free(chip->dma.rx_chan);
293 	return snd_pcm_lib_free_pages(substream);
294 }
295 
296 static int atmel_ac97c_playback_prepare(struct snd_pcm_substream *substream)
297 {
298 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
299 	struct snd_pcm_runtime *runtime = substream->runtime;
300 	unsigned long word = 0;
301 	int retval;
302 
303 	/* assign channels to AC97C channel A */
304 	switch (runtime->channels) {
305 	case 1:
306 		word |= AC97C_CH_ASSIGN(PCM_LEFT, A);
307 		break;
308 	case 2:
309 		word |= AC97C_CH_ASSIGN(PCM_LEFT, A)
310 			| AC97C_CH_ASSIGN(PCM_RIGHT, A);
311 		break;
312 	default:
313 		/* TODO: support more than two channels */
314 		return -EINVAL;
315 		break;
316 	}
317 	ac97c_writel(chip, OCA, word);
318 
319 	/* configure sample format and size */
320 	word = AC97C_CMR_DMAEN | AC97C_CMR_SIZE_16;
321 
322 	switch (runtime->format) {
323 	case SNDRV_PCM_FORMAT_S16_LE:
324 		word |= AC97C_CMR_CEM_LITTLE;
325 		break;
326 	case SNDRV_PCM_FORMAT_S16_BE: /* fall through */
327 	default:
328 		word &= ~(AC97C_CMR_CEM_LITTLE);
329 		break;
330 	}
331 
332 	ac97c_writel(chip, CAMR, word);
333 
334 	/* set variable rate if needed */
335 	if (runtime->rate != 48000) {
336 		word = ac97c_readl(chip, MR);
337 		word |= AC97C_MR_VRA;
338 		ac97c_writel(chip, MR, word);
339 	} else {
340 		word = ac97c_readl(chip, MR);
341 		word &= ~(AC97C_MR_VRA);
342 		ac97c_writel(chip, MR, word);
343 	}
344 
345 	retval = snd_ac97_set_rate(chip->ac97, AC97_PCM_FRONT_DAC_RATE,
346 			runtime->rate);
347 	if (retval)
348 		dev_dbg(&chip->pdev->dev, "could not set rate %d Hz\n",
349 				runtime->rate);
350 
351 	if (!test_bit(DMA_TX_READY, &chip->flags))
352 		retval = atmel_ac97c_prepare_dma(chip, substream,
353 				DMA_TO_DEVICE);
354 
355 	return retval;
356 }
357 
358 static int atmel_ac97c_capture_prepare(struct snd_pcm_substream *substream)
359 {
360 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
361 	struct snd_pcm_runtime *runtime = substream->runtime;
362 	unsigned long word = 0;
363 	int retval;
364 
365 	/* assign channels to AC97C channel A */
366 	switch (runtime->channels) {
367 	case 1:
368 		word |= AC97C_CH_ASSIGN(PCM_LEFT, A);
369 		break;
370 	case 2:
371 		word |= AC97C_CH_ASSIGN(PCM_LEFT, A)
372 			| AC97C_CH_ASSIGN(PCM_RIGHT, A);
373 		break;
374 	default:
375 		/* TODO: support more than two channels */
376 		return -EINVAL;
377 		break;
378 	}
379 	ac97c_writel(chip, ICA, word);
380 
381 	/* configure sample format and size */
382 	word = AC97C_CMR_DMAEN | AC97C_CMR_SIZE_16;
383 
384 	switch (runtime->format) {
385 	case SNDRV_PCM_FORMAT_S16_LE:
386 		word |= AC97C_CMR_CEM_LITTLE;
387 		break;
388 	case SNDRV_PCM_FORMAT_S16_BE: /* fall through */
389 	default:
390 		word &= ~(AC97C_CMR_CEM_LITTLE);
391 		break;
392 	}
393 
394 	ac97c_writel(chip, CAMR, word);
395 
396 	/* set variable rate if needed */
397 	if (runtime->rate != 48000) {
398 		word = ac97c_readl(chip, MR);
399 		word |= AC97C_MR_VRA;
400 		ac97c_writel(chip, MR, word);
401 	} else {
402 		word = ac97c_readl(chip, MR);
403 		word &= ~(AC97C_MR_VRA);
404 		ac97c_writel(chip, MR, word);
405 	}
406 
407 	retval = snd_ac97_set_rate(chip->ac97, AC97_PCM_LR_ADC_RATE,
408 			runtime->rate);
409 	if (retval)
410 		dev_dbg(&chip->pdev->dev, "could not set rate %d Hz\n",
411 				runtime->rate);
412 
413 	if (!test_bit(DMA_RX_READY, &chip->flags))
414 		retval = atmel_ac97c_prepare_dma(chip, substream,
415 				DMA_FROM_DEVICE);
416 
417 	return retval;
418 }
419 
420 static int
421 atmel_ac97c_playback_trigger(struct snd_pcm_substream *substream, int cmd)
422 {
423 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
424 	unsigned long camr;
425 	int retval = 0;
426 
427 	camr = ac97c_readl(chip, CAMR);
428 
429 	switch (cmd) {
430 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: /* fall through */
431 	case SNDRV_PCM_TRIGGER_RESUME: /* fall through */
432 	case SNDRV_PCM_TRIGGER_START:
433 		retval = dw_dma_cyclic_start(chip->dma.tx_chan);
434 		if (retval)
435 			goto out;
436 		camr |= AC97C_CMR_CENA;
437 		break;
438 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH: /* fall through */
439 	case SNDRV_PCM_TRIGGER_SUSPEND: /* fall through */
440 	case SNDRV_PCM_TRIGGER_STOP:
441 		dw_dma_cyclic_stop(chip->dma.tx_chan);
442 		if (chip->opened <= 1)
443 			camr &= ~AC97C_CMR_CENA;
444 		break;
445 	default:
446 		retval = -EINVAL;
447 		goto out;
448 	}
449 
450 	ac97c_writel(chip, CAMR, camr);
451 out:
452 	return retval;
453 }
454 
455 static int
456 atmel_ac97c_capture_trigger(struct snd_pcm_substream *substream, int cmd)
457 {
458 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
459 	unsigned long camr;
460 	int retval = 0;
461 
462 	camr = ac97c_readl(chip, CAMR);
463 
464 	switch (cmd) {
465 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: /* fall through */
466 	case SNDRV_PCM_TRIGGER_RESUME: /* fall through */
467 	case SNDRV_PCM_TRIGGER_START:
468 		retval = dw_dma_cyclic_start(chip->dma.rx_chan);
469 		if (retval)
470 			goto out;
471 		camr |= AC97C_CMR_CENA;
472 		break;
473 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH: /* fall through */
474 	case SNDRV_PCM_TRIGGER_SUSPEND: /* fall through */
475 	case SNDRV_PCM_TRIGGER_STOP:
476 		dw_dma_cyclic_stop(chip->dma.rx_chan);
477 		if (chip->opened <= 1)
478 			camr &= ~AC97C_CMR_CENA;
479 		break;
480 	default:
481 		retval = -EINVAL;
482 		break;
483 	}
484 
485 	ac97c_writel(chip, CAMR, camr);
486 out:
487 	return retval;
488 }
489 
490 static snd_pcm_uframes_t
491 atmel_ac97c_playback_pointer(struct snd_pcm_substream *substream)
492 {
493 	struct atmel_ac97c	*chip = snd_pcm_substream_chip(substream);
494 	struct snd_pcm_runtime	*runtime = substream->runtime;
495 	snd_pcm_uframes_t	frames;
496 	unsigned long		bytes;
497 
498 	bytes = dw_dma_get_src_addr(chip->dma.tx_chan);
499 	bytes -= runtime->dma_addr;
500 
501 	frames = bytes_to_frames(runtime, bytes);
502 	if (frames >= runtime->buffer_size)
503 		frames -= runtime->buffer_size;
504 	return frames;
505 }
506 
507 static snd_pcm_uframes_t
508 atmel_ac97c_capture_pointer(struct snd_pcm_substream *substream)
509 {
510 	struct atmel_ac97c	*chip = snd_pcm_substream_chip(substream);
511 	struct snd_pcm_runtime	*runtime = substream->runtime;
512 	snd_pcm_uframes_t	frames;
513 	unsigned long		bytes;
514 
515 	bytes = dw_dma_get_dst_addr(chip->dma.rx_chan);
516 	bytes -= runtime->dma_addr;
517 
518 	frames = bytes_to_frames(runtime, bytes);
519 	if (frames >= runtime->buffer_size)
520 		frames -= runtime->buffer_size;
521 	return frames;
522 }
523 
524 static struct snd_pcm_ops atmel_ac97_playback_ops = {
525 	.open		= atmel_ac97c_playback_open,
526 	.close		= atmel_ac97c_playback_close,
527 	.ioctl		= snd_pcm_lib_ioctl,
528 	.hw_params	= atmel_ac97c_playback_hw_params,
529 	.hw_free	= atmel_ac97c_playback_hw_free,
530 	.prepare	= atmel_ac97c_playback_prepare,
531 	.trigger	= atmel_ac97c_playback_trigger,
532 	.pointer	= atmel_ac97c_playback_pointer,
533 };
534 
535 static struct snd_pcm_ops atmel_ac97_capture_ops = {
536 	.open		= atmel_ac97c_capture_open,
537 	.close		= atmel_ac97c_capture_close,
538 	.ioctl		= snd_pcm_lib_ioctl,
539 	.hw_params	= atmel_ac97c_capture_hw_params,
540 	.hw_free	= atmel_ac97c_capture_hw_free,
541 	.prepare	= atmel_ac97c_capture_prepare,
542 	.trigger	= atmel_ac97c_capture_trigger,
543 	.pointer	= atmel_ac97c_capture_pointer,
544 };
545 
546 static int __devinit atmel_ac97c_pcm_new(struct atmel_ac97c *chip)
547 {
548 	struct snd_pcm		*pcm;
549 	struct snd_pcm_hardware	hw = atmel_ac97c_hw;
550 	int			capture, playback, retval;
551 
552 	capture = test_bit(DMA_RX_CHAN_PRESENT, &chip->flags);
553 	playback = test_bit(DMA_TX_CHAN_PRESENT, &chip->flags);
554 
555 	retval = snd_pcm_new(chip->card, chip->card->shortname,
556 			chip->pdev->id, playback, capture, &pcm);
557 	if (retval)
558 		return retval;
559 
560 	if (capture)
561 		snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE,
562 				&atmel_ac97_capture_ops);
563 	if (playback)
564 		snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK,
565 				&atmel_ac97_playback_ops);
566 
567 	retval = snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
568 			&chip->pdev->dev, hw.periods_min * hw.period_bytes_min,
569 			hw.buffer_bytes_max);
570 	if (retval)
571 		return retval;
572 
573 	pcm->private_data = chip;
574 	pcm->info_flags = 0;
575 	strcpy(pcm->name, chip->card->shortname);
576 	chip->pcm = pcm;
577 
578 	return 0;
579 }
580 
581 static int atmel_ac97c_mixer_new(struct atmel_ac97c *chip)
582 {
583 	struct snd_ac97_template template;
584 	memset(&template, 0, sizeof(template));
585 	template.private_data = chip;
586 	return snd_ac97_mixer(chip->ac97_bus, &template, &chip->ac97);
587 }
588 
589 static void atmel_ac97c_write(struct snd_ac97 *ac97, unsigned short reg,
590 		unsigned short val)
591 {
592 	struct atmel_ac97c *chip = get_chip(ac97);
593 	unsigned long word;
594 	int timeout = 40;
595 
596 	word = (reg & 0x7f) << 16 | val;
597 
598 	do {
599 		if (ac97c_readl(chip, COSR) & AC97C_CSR_TXRDY) {
600 			ac97c_writel(chip, COTHR, word);
601 			return;
602 		}
603 		udelay(1);
604 	} while (--timeout);
605 
606 	dev_dbg(&chip->pdev->dev, "codec write timeout\n");
607 }
608 
609 static unsigned short atmel_ac97c_read(struct snd_ac97 *ac97,
610 		unsigned short reg)
611 {
612 	struct atmel_ac97c *chip = get_chip(ac97);
613 	unsigned long word;
614 	int timeout = 40;
615 	int write = 10;
616 
617 	word = (0x80 | (reg & 0x7f)) << 16;
618 
619 	if ((ac97c_readl(chip, COSR) & AC97C_CSR_RXRDY) != 0)
620 		ac97c_readl(chip, CORHR);
621 
622 retry_write:
623 	timeout = 40;
624 
625 	do {
626 		if ((ac97c_readl(chip, COSR) & AC97C_CSR_TXRDY) != 0) {
627 			ac97c_writel(chip, COTHR, word);
628 			goto read_reg;
629 		}
630 		udelay(10);
631 	} while (--timeout);
632 
633 	if (!--write)
634 		goto timed_out;
635 	goto retry_write;
636 
637 read_reg:
638 	do {
639 		if ((ac97c_readl(chip, COSR) & AC97C_CSR_RXRDY) != 0) {
640 			unsigned short val = ac97c_readl(chip, CORHR);
641 			return val;
642 		}
643 		udelay(10);
644 	} while (--timeout);
645 
646 	if (!--write)
647 		goto timed_out;
648 	goto retry_write;
649 
650 timed_out:
651 	dev_dbg(&chip->pdev->dev, "codec read timeout\n");
652 	return 0xffff;
653 }
654 
655 static bool filter(struct dma_chan *chan, void *slave)
656 {
657 	struct dw_dma_slave *dws = slave;
658 
659 	if (dws->dma_dev == chan->device->dev) {
660 		chan->private = dws;
661 		return true;
662 	} else
663 		return false;
664 }
665 
666 static void atmel_ac97c_reset(struct atmel_ac97c *chip)
667 {
668 	ac97c_writel(chip, MR, AC97C_MR_WRST);
669 
670 	if (gpio_is_valid(chip->reset_pin)) {
671 		gpio_set_value(chip->reset_pin, 0);
672 		/* AC97 v2.2 specifications says minimum 1 us. */
673 		udelay(10);
674 		gpio_set_value(chip->reset_pin, 1);
675 	}
676 
677 	udelay(1);
678 	ac97c_writel(chip, MR, AC97C_MR_ENA);
679 }
680 
681 static int __devinit atmel_ac97c_probe(struct platform_device *pdev)
682 {
683 	struct snd_card			*card;
684 	struct atmel_ac97c		*chip;
685 	struct resource			*regs;
686 	struct ac97c_platform_data	*pdata;
687 	struct clk			*pclk;
688 	static struct snd_ac97_bus_ops	ops = {
689 		.write	= atmel_ac97c_write,
690 		.read	= atmel_ac97c_read,
691 	};
692 	int				retval;
693 
694 	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
695 	if (!regs) {
696 		dev_dbg(&pdev->dev, "no memory resource\n");
697 		return -ENXIO;
698 	}
699 
700 	pdata = pdev->dev.platform_data;
701 	if (!pdata) {
702 		dev_dbg(&pdev->dev, "no platform data\n");
703 		return -ENXIO;
704 	}
705 
706 	pclk = clk_get(&pdev->dev, "pclk");
707 	if (IS_ERR(pclk)) {
708 		dev_dbg(&pdev->dev, "no peripheral clock\n");
709 		return PTR_ERR(pclk);
710 	}
711 	clk_enable(pclk);
712 
713 	retval = snd_card_create(SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1,
714 			THIS_MODULE, sizeof(struct atmel_ac97c), &card);
715 	if (retval) {
716 		dev_dbg(&pdev->dev, "could not create sound card device\n");
717 		goto err_snd_card_new;
718 	}
719 
720 	chip = get_chip(card);
721 
722 	spin_lock_init(&chip->lock);
723 
724 	strcpy(card->driver, "Atmel AC97C");
725 	strcpy(card->shortname, "Atmel AC97C");
726 	sprintf(card->longname, "Atmel AC97 controller");
727 
728 	chip->card = card;
729 	chip->pclk = pclk;
730 	chip->pdev = pdev;
731 	chip->regs = ioremap(regs->start, regs->end - regs->start + 1);
732 
733 	if (!chip->regs) {
734 		dev_dbg(&pdev->dev, "could not remap register memory\n");
735 		goto err_ioremap;
736 	}
737 
738 	if (gpio_is_valid(pdata->reset_pin)) {
739 		if (gpio_request(pdata->reset_pin, "reset_pin")) {
740 			dev_dbg(&pdev->dev, "reset pin not available\n");
741 			chip->reset_pin = -ENODEV;
742 		} else {
743 			gpio_direction_output(pdata->reset_pin, 1);
744 			chip->reset_pin = pdata->reset_pin;
745 		}
746 	}
747 
748 	snd_card_set_dev(card, &pdev->dev);
749 
750 	retval = snd_ac97_bus(card, 0, &ops, chip, &chip->ac97_bus);
751 	if (retval) {
752 		dev_dbg(&pdev->dev, "could not register on ac97 bus\n");
753 		goto err_ac97_bus;
754 	}
755 
756 	atmel_ac97c_reset(chip);
757 
758 	retval = atmel_ac97c_mixer_new(chip);
759 	if (retval) {
760 		dev_dbg(&pdev->dev, "could not register ac97 mixer\n");
761 		goto err_ac97_bus;
762 	}
763 
764 	if (pdata->rx_dws.dma_dev) {
765 		struct dw_dma_slave *dws = &pdata->rx_dws;
766 		dma_cap_mask_t mask;
767 
768 		dws->rx_reg = regs->start + AC97C_CARHR + 2;
769 
770 		dma_cap_zero(mask);
771 		dma_cap_set(DMA_SLAVE, mask);
772 
773 		chip->dma.rx_chan = dma_request_channel(mask, filter, dws);
774 
775 		dev_info(&chip->pdev->dev, "using %s for DMA RX\n",
776 					chip->dma.rx_chan->dev->device.bus_id);
777 		set_bit(DMA_RX_CHAN_PRESENT, &chip->flags);
778 	}
779 
780 	if (pdata->tx_dws.dma_dev) {
781 		struct dw_dma_slave *dws = &pdata->tx_dws;
782 		dma_cap_mask_t mask;
783 
784 		dws->tx_reg = regs->start + AC97C_CATHR + 2;
785 
786 		dma_cap_zero(mask);
787 		dma_cap_set(DMA_SLAVE, mask);
788 
789 		chip->dma.tx_chan = dma_request_channel(mask, filter, dws);
790 
791 		dev_info(&chip->pdev->dev, "using %s for DMA TX\n",
792 					chip->dma.tx_chan->dev->device.bus_id);
793 		set_bit(DMA_TX_CHAN_PRESENT, &chip->flags);
794 	}
795 
796 	if (!test_bit(DMA_RX_CHAN_PRESENT, &chip->flags) &&
797 			!test_bit(DMA_TX_CHAN_PRESENT, &chip->flags)) {
798 		dev_dbg(&pdev->dev, "DMA not available\n");
799 		retval = -ENODEV;
800 		goto err_dma;
801 	}
802 
803 	retval = atmel_ac97c_pcm_new(chip);
804 	if (retval) {
805 		dev_dbg(&pdev->dev, "could not register ac97 pcm device\n");
806 		goto err_dma;
807 	}
808 
809 	retval = snd_card_register(card);
810 	if (retval) {
811 		dev_dbg(&pdev->dev, "could not register sound card\n");
812 		goto err_ac97_bus;
813 	}
814 
815 	platform_set_drvdata(pdev, card);
816 
817 	dev_info(&pdev->dev, "Atmel AC97 controller at 0x%p\n",
818 			chip->regs);
819 
820 	return 0;
821 
822 err_dma:
823 	if (test_bit(DMA_RX_CHAN_PRESENT, &chip->flags))
824 		dma_release_channel(chip->dma.rx_chan);
825 	if (test_bit(DMA_TX_CHAN_PRESENT, &chip->flags))
826 		dma_release_channel(chip->dma.tx_chan);
827 	clear_bit(DMA_RX_CHAN_PRESENT, &chip->flags);
828 	clear_bit(DMA_TX_CHAN_PRESENT, &chip->flags);
829 	chip->dma.rx_chan = NULL;
830 	chip->dma.tx_chan = NULL;
831 err_ac97_bus:
832 	snd_card_set_dev(card, NULL);
833 
834 	if (gpio_is_valid(chip->reset_pin))
835 		gpio_free(chip->reset_pin);
836 
837 	iounmap(chip->regs);
838 err_ioremap:
839 	snd_card_free(card);
840 err_snd_card_new:
841 	clk_disable(pclk);
842 	clk_put(pclk);
843 	return retval;
844 }
845 
846 #ifdef CONFIG_PM
847 static int atmel_ac97c_suspend(struct platform_device *pdev, pm_message_t msg)
848 {
849 	struct snd_card *card = platform_get_drvdata(pdev);
850 	struct atmel_ac97c *chip = card->private_data;
851 
852 	if (test_bit(DMA_RX_READY, &chip->flags))
853 		dw_dma_cyclic_stop(chip->dma.rx_chan);
854 	if (test_bit(DMA_TX_READY, &chip->flags))
855 		dw_dma_cyclic_stop(chip->dma.tx_chan);
856 	clk_disable(chip->pclk);
857 
858 	return 0;
859 }
860 
861 static int atmel_ac97c_resume(struct platform_device *pdev)
862 {
863 	struct snd_card *card = platform_get_drvdata(pdev);
864 	struct atmel_ac97c *chip = card->private_data;
865 
866 	clk_enable(chip->pclk);
867 	if (test_bit(DMA_RX_READY, &chip->flags))
868 		dw_dma_cyclic_start(chip->dma.rx_chan);
869 	if (test_bit(DMA_TX_READY, &chip->flags))
870 		dw_dma_cyclic_start(chip->dma.tx_chan);
871 
872 	return 0;
873 }
874 #else
875 #define atmel_ac97c_suspend NULL
876 #define atmel_ac97c_resume NULL
877 #endif
878 
879 static int __devexit atmel_ac97c_remove(struct platform_device *pdev)
880 {
881 	struct snd_card *card = platform_get_drvdata(pdev);
882 	struct atmel_ac97c *chip = get_chip(card);
883 
884 	if (gpio_is_valid(chip->reset_pin))
885 		gpio_free(chip->reset_pin);
886 
887 	clk_disable(chip->pclk);
888 	clk_put(chip->pclk);
889 	iounmap(chip->regs);
890 
891 	if (test_bit(DMA_RX_CHAN_PRESENT, &chip->flags))
892 		dma_release_channel(chip->dma.rx_chan);
893 	if (test_bit(DMA_TX_CHAN_PRESENT, &chip->flags))
894 		dma_release_channel(chip->dma.tx_chan);
895 	clear_bit(DMA_RX_CHAN_PRESENT, &chip->flags);
896 	clear_bit(DMA_TX_CHAN_PRESENT, &chip->flags);
897 	chip->dma.rx_chan = NULL;
898 	chip->dma.tx_chan = NULL;
899 
900 	snd_card_set_dev(card, NULL);
901 	snd_card_free(card);
902 
903 	platform_set_drvdata(pdev, NULL);
904 
905 	return 0;
906 }
907 
908 static struct platform_driver atmel_ac97c_driver = {
909 	.remove		= __devexit_p(atmel_ac97c_remove),
910 	.driver		= {
911 		.name	= "atmel_ac97c",
912 	},
913 	.suspend	= atmel_ac97c_suspend,
914 	.resume		= atmel_ac97c_resume,
915 };
916 
917 static int __init atmel_ac97c_init(void)
918 {
919 	return platform_driver_probe(&atmel_ac97c_driver,
920 			atmel_ac97c_probe);
921 }
922 module_init(atmel_ac97c_init);
923 
924 static void __exit atmel_ac97c_exit(void)
925 {
926 	platform_driver_unregister(&atmel_ac97c_driver);
927 }
928 module_exit(atmel_ac97c_exit);
929 
930 MODULE_LICENSE("GPL");
931 MODULE_DESCRIPTION("Driver for Atmel AC97 controller");
932 MODULE_AUTHOR("Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>");
933