xref: /linux/sound/atmel/ac97c.c (revision 6ee738610f41b59733f63718f0bdbcba7d3a3f12)
1 /*
2  * Driver for Atmel AC97C
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/device.h>
14 #include <linux/dmaengine.h>
15 #include <linux/dma-mapping.h>
16 #include <linux/init.h>
17 #include <linux/interrupt.h>
18 #include <linux/module.h>
19 #include <linux/platform_device.h>
20 #include <linux/mutex.h>
21 #include <linux/gpio.h>
22 #include <linux/io.h>
23 
24 #include <sound/core.h>
25 #include <sound/initval.h>
26 #include <sound/pcm.h>
27 #include <sound/pcm_params.h>
28 #include <sound/ac97_codec.h>
29 #include <sound/atmel-ac97c.h>
30 #include <sound/memalloc.h>
31 
32 #include <linux/dw_dmac.h>
33 
34 #include "ac97c.h"
35 
36 enum {
37 	DMA_TX_READY = 0,
38 	DMA_RX_READY,
39 	DMA_TX_CHAN_PRESENT,
40 	DMA_RX_CHAN_PRESENT,
41 };
42 
43 /* Serialize access to opened variable */
44 static DEFINE_MUTEX(opened_mutex);
45 
46 struct atmel_ac97c_dma {
47 	struct dma_chan			*rx_chan;
48 	struct dma_chan			*tx_chan;
49 };
50 
51 struct atmel_ac97c {
52 	struct clk			*pclk;
53 	struct platform_device		*pdev;
54 	struct atmel_ac97c_dma		dma;
55 
56 	struct snd_pcm_substream	*playback_substream;
57 	struct snd_pcm_substream	*capture_substream;
58 	struct snd_card			*card;
59 	struct snd_pcm			*pcm;
60 	struct snd_ac97			*ac97;
61 	struct snd_ac97_bus		*ac97_bus;
62 
63 	u64				cur_format;
64 	unsigned int			cur_rate;
65 	unsigned long			flags;
66 	/* Serialize access to opened variable */
67 	spinlock_t			lock;
68 	void __iomem			*regs;
69 	int				irq;
70 	int				opened;
71 	int				reset_pin;
72 };
73 
74 #define get_chip(card) ((struct atmel_ac97c *)(card)->private_data)
75 
76 #define ac97c_writel(chip, reg, val)			\
77 	__raw_writel((val), (chip)->regs + AC97C_##reg)
78 #define ac97c_readl(chip, reg)				\
79 	__raw_readl((chip)->regs + AC97C_##reg)
80 
81 /* This function is called by the DMA driver. */
82 static void atmel_ac97c_dma_playback_period_done(void *arg)
83 {
84 	struct atmel_ac97c *chip = arg;
85 	snd_pcm_period_elapsed(chip->playback_substream);
86 }
87 
88 static void atmel_ac97c_dma_capture_period_done(void *arg)
89 {
90 	struct atmel_ac97c *chip = arg;
91 	snd_pcm_period_elapsed(chip->capture_substream);
92 }
93 
94 static int atmel_ac97c_prepare_dma(struct atmel_ac97c *chip,
95 		struct snd_pcm_substream *substream,
96 		enum dma_data_direction direction)
97 {
98 	struct dma_chan			*chan;
99 	struct dw_cyclic_desc		*cdesc;
100 	struct snd_pcm_runtime		*runtime = substream->runtime;
101 	unsigned long			buffer_len, period_len;
102 
103 	/*
104 	 * We don't do DMA on "complex" transfers, i.e. with
105 	 * non-halfword-aligned buffers or lengths.
106 	 */
107 	if (runtime->dma_addr & 1 || runtime->buffer_size & 1) {
108 		dev_dbg(&chip->pdev->dev, "too complex transfer\n");
109 		return -EINVAL;
110 	}
111 
112 	if (direction == DMA_TO_DEVICE)
113 		chan = chip->dma.tx_chan;
114 	else
115 		chan = chip->dma.rx_chan;
116 
117 	buffer_len = frames_to_bytes(runtime, runtime->buffer_size);
118 	period_len = frames_to_bytes(runtime, runtime->period_size);
119 
120 	cdesc = dw_dma_cyclic_prep(chan, runtime->dma_addr, buffer_len,
121 			period_len, direction);
122 	if (IS_ERR(cdesc)) {
123 		dev_dbg(&chip->pdev->dev, "could not prepare cyclic DMA\n");
124 		return PTR_ERR(cdesc);
125 	}
126 
127 	if (direction == DMA_TO_DEVICE) {
128 		cdesc->period_callback = atmel_ac97c_dma_playback_period_done;
129 		set_bit(DMA_TX_READY, &chip->flags);
130 	} else {
131 		cdesc->period_callback = atmel_ac97c_dma_capture_period_done;
132 		set_bit(DMA_RX_READY, &chip->flags);
133 	}
134 
135 	cdesc->period_callback_param = chip;
136 
137 	return 0;
138 }
139 
140 static struct snd_pcm_hardware atmel_ac97c_hw = {
141 	.info			= (SNDRV_PCM_INFO_MMAP
142 				  | SNDRV_PCM_INFO_MMAP_VALID
143 				  | SNDRV_PCM_INFO_INTERLEAVED
144 				  | SNDRV_PCM_INFO_BLOCK_TRANSFER
145 				  | SNDRV_PCM_INFO_JOINT_DUPLEX
146 				  | SNDRV_PCM_INFO_RESUME
147 				  | SNDRV_PCM_INFO_PAUSE),
148 	.formats		= (SNDRV_PCM_FMTBIT_S16_BE
149 				  | SNDRV_PCM_FMTBIT_S16_LE),
150 	.rates			= (SNDRV_PCM_RATE_CONTINUOUS),
151 	.rate_min		= 4000,
152 	.rate_max		= 48000,
153 	.channels_min		= 1,
154 	.channels_max		= 2,
155 	.buffer_bytes_max	= 2 * 2 * 64 * 2048,
156 	.period_bytes_min	= 4096,
157 	.period_bytes_max	= 4096,
158 	.periods_min		= 6,
159 	.periods_max		= 64,
160 };
161 
162 static int atmel_ac97c_playback_open(struct snd_pcm_substream *substream)
163 {
164 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
165 	struct snd_pcm_runtime *runtime = substream->runtime;
166 
167 	mutex_lock(&opened_mutex);
168 	chip->opened++;
169 	runtime->hw = atmel_ac97c_hw;
170 	if (chip->cur_rate) {
171 		runtime->hw.rate_min = chip->cur_rate;
172 		runtime->hw.rate_max = chip->cur_rate;
173 	}
174 	if (chip->cur_format)
175 		runtime->hw.formats = (1ULL << chip->cur_format);
176 	mutex_unlock(&opened_mutex);
177 	chip->playback_substream = substream;
178 	return 0;
179 }
180 
181 static int atmel_ac97c_capture_open(struct snd_pcm_substream *substream)
182 {
183 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
184 	struct snd_pcm_runtime *runtime = substream->runtime;
185 
186 	mutex_lock(&opened_mutex);
187 	chip->opened++;
188 	runtime->hw = atmel_ac97c_hw;
189 	if (chip->cur_rate) {
190 		runtime->hw.rate_min = chip->cur_rate;
191 		runtime->hw.rate_max = chip->cur_rate;
192 	}
193 	if (chip->cur_format)
194 		runtime->hw.formats = (1ULL << chip->cur_format);
195 	mutex_unlock(&opened_mutex);
196 	chip->capture_substream = substream;
197 	return 0;
198 }
199 
200 static int atmel_ac97c_playback_close(struct snd_pcm_substream *substream)
201 {
202 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
203 
204 	mutex_lock(&opened_mutex);
205 	chip->opened--;
206 	if (!chip->opened) {
207 		chip->cur_rate = 0;
208 		chip->cur_format = 0;
209 	}
210 	mutex_unlock(&opened_mutex);
211 
212 	chip->playback_substream = NULL;
213 
214 	return 0;
215 }
216 
217 static int atmel_ac97c_capture_close(struct snd_pcm_substream *substream)
218 {
219 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
220 
221 	mutex_lock(&opened_mutex);
222 	chip->opened--;
223 	if (!chip->opened) {
224 		chip->cur_rate = 0;
225 		chip->cur_format = 0;
226 	}
227 	mutex_unlock(&opened_mutex);
228 
229 	chip->capture_substream = NULL;
230 
231 	return 0;
232 }
233 
234 static int atmel_ac97c_playback_hw_params(struct snd_pcm_substream *substream,
235 		struct snd_pcm_hw_params *hw_params)
236 {
237 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
238 	int retval;
239 
240 	retval = snd_pcm_lib_malloc_pages(substream,
241 					params_buffer_bytes(hw_params));
242 	if (retval < 0)
243 		return retval;
244 	/* snd_pcm_lib_malloc_pages returns 1 if buffer is changed. */
245 	if (retval == 1)
246 		if (test_and_clear_bit(DMA_TX_READY, &chip->flags))
247 			dw_dma_cyclic_free(chip->dma.tx_chan);
248 
249 	/* Set restrictions to params. */
250 	mutex_lock(&opened_mutex);
251 	chip->cur_rate = params_rate(hw_params);
252 	chip->cur_format = params_format(hw_params);
253 	mutex_unlock(&opened_mutex);
254 
255 	return retval;
256 }
257 
258 static int atmel_ac97c_capture_hw_params(struct snd_pcm_substream *substream,
259 		struct snd_pcm_hw_params *hw_params)
260 {
261 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
262 	int retval;
263 
264 	retval = snd_pcm_lib_malloc_pages(substream,
265 					params_buffer_bytes(hw_params));
266 	if (retval < 0)
267 		return retval;
268 	/* snd_pcm_lib_malloc_pages returns 1 if buffer is changed. */
269 	if (retval == 1)
270 		if (test_and_clear_bit(DMA_RX_READY, &chip->flags))
271 			dw_dma_cyclic_free(chip->dma.rx_chan);
272 
273 	/* Set restrictions to params. */
274 	mutex_lock(&opened_mutex);
275 	chip->cur_rate = params_rate(hw_params);
276 	chip->cur_format = params_format(hw_params);
277 	mutex_unlock(&opened_mutex);
278 
279 	return retval;
280 }
281 
282 static int atmel_ac97c_playback_hw_free(struct snd_pcm_substream *substream)
283 {
284 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
285 	if (test_and_clear_bit(DMA_TX_READY, &chip->flags))
286 		dw_dma_cyclic_free(chip->dma.tx_chan);
287 	return snd_pcm_lib_free_pages(substream);
288 }
289 
290 static int atmel_ac97c_capture_hw_free(struct snd_pcm_substream *substream)
291 {
292 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
293 	if (test_and_clear_bit(DMA_RX_READY, &chip->flags))
294 		dw_dma_cyclic_free(chip->dma.rx_chan);
295 	return snd_pcm_lib_free_pages(substream);
296 }
297 
298 static int atmel_ac97c_playback_prepare(struct snd_pcm_substream *substream)
299 {
300 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
301 	struct snd_pcm_runtime *runtime = substream->runtime;
302 	unsigned long word = ac97c_readl(chip, OCA);
303 	int retval;
304 
305 	word &= ~(AC97C_CH_MASK(PCM_LEFT) | AC97C_CH_MASK(PCM_RIGHT));
306 
307 	/* assign channels to AC97C channel A */
308 	switch (runtime->channels) {
309 	case 1:
310 		word |= AC97C_CH_ASSIGN(PCM_LEFT, A);
311 		break;
312 	case 2:
313 		word |= AC97C_CH_ASSIGN(PCM_LEFT, A)
314 			| AC97C_CH_ASSIGN(PCM_RIGHT, A);
315 		break;
316 	default:
317 		/* TODO: support more than two channels */
318 		return -EINVAL;
319 	}
320 	ac97c_writel(chip, OCA, word);
321 
322 	/* configure sample format and size */
323 	word = AC97C_CMR_DMAEN | AC97C_CMR_SIZE_16;
324 
325 	switch (runtime->format) {
326 	case SNDRV_PCM_FORMAT_S16_LE:
327 		word |= AC97C_CMR_CEM_LITTLE;
328 		break;
329 	case SNDRV_PCM_FORMAT_S16_BE: /* fall through */
330 		word &= ~(AC97C_CMR_CEM_LITTLE);
331 		break;
332 	default:
333 		word = ac97c_readl(chip, OCA);
334 		word &= ~(AC97C_CH_MASK(PCM_LEFT) | AC97C_CH_MASK(PCM_RIGHT));
335 		ac97c_writel(chip, OCA, word);
336 		return -EINVAL;
337 	}
338 
339 	/* Enable underrun interrupt on channel A */
340 	word |= AC97C_CSR_UNRUN;
341 
342 	ac97c_writel(chip, CAMR, word);
343 
344 	/* Enable channel A event interrupt */
345 	word = ac97c_readl(chip, IMR);
346 	word |= AC97C_SR_CAEVT;
347 	ac97c_writel(chip, IER, word);
348 
349 	/* set variable rate if needed */
350 	if (runtime->rate != 48000) {
351 		word = ac97c_readl(chip, MR);
352 		word |= AC97C_MR_VRA;
353 		ac97c_writel(chip, MR, word);
354 	} else {
355 		word = ac97c_readl(chip, MR);
356 		word &= ~(AC97C_MR_VRA);
357 		ac97c_writel(chip, MR, word);
358 	}
359 
360 	retval = snd_ac97_set_rate(chip->ac97, AC97_PCM_FRONT_DAC_RATE,
361 			runtime->rate);
362 	if (retval)
363 		dev_dbg(&chip->pdev->dev, "could not set rate %d Hz\n",
364 				runtime->rate);
365 
366 	if (!test_bit(DMA_TX_READY, &chip->flags))
367 		retval = atmel_ac97c_prepare_dma(chip, substream,
368 				DMA_TO_DEVICE);
369 
370 	return retval;
371 }
372 
373 static int atmel_ac97c_capture_prepare(struct snd_pcm_substream *substream)
374 {
375 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
376 	struct snd_pcm_runtime *runtime = substream->runtime;
377 	unsigned long word = ac97c_readl(chip, ICA);
378 	int retval;
379 
380 	word &= ~(AC97C_CH_MASK(PCM_LEFT) | AC97C_CH_MASK(PCM_RIGHT));
381 
382 	/* assign channels to AC97C channel A */
383 	switch (runtime->channels) {
384 	case 1:
385 		word |= AC97C_CH_ASSIGN(PCM_LEFT, A);
386 		break;
387 	case 2:
388 		word |= AC97C_CH_ASSIGN(PCM_LEFT, A)
389 			| AC97C_CH_ASSIGN(PCM_RIGHT, A);
390 		break;
391 	default:
392 		/* TODO: support more than two channels */
393 		return -EINVAL;
394 	}
395 	ac97c_writel(chip, ICA, word);
396 
397 	/* configure sample format and size */
398 	word = AC97C_CMR_DMAEN | AC97C_CMR_SIZE_16;
399 
400 	switch (runtime->format) {
401 	case SNDRV_PCM_FORMAT_S16_LE:
402 		word |= AC97C_CMR_CEM_LITTLE;
403 		break;
404 	case SNDRV_PCM_FORMAT_S16_BE: /* fall through */
405 		word &= ~(AC97C_CMR_CEM_LITTLE);
406 		break;
407 	default:
408 		word = ac97c_readl(chip, ICA);
409 		word &= ~(AC97C_CH_MASK(PCM_LEFT) | AC97C_CH_MASK(PCM_RIGHT));
410 		ac97c_writel(chip, ICA, word);
411 		return -EINVAL;
412 	}
413 
414 	/* Enable overrun interrupt on channel A */
415 	word |= AC97C_CSR_OVRUN;
416 
417 	ac97c_writel(chip, CAMR, word);
418 
419 	/* Enable channel A event interrupt */
420 	word = ac97c_readl(chip, IMR);
421 	word |= AC97C_SR_CAEVT;
422 	ac97c_writel(chip, IER, word);
423 
424 	/* set variable rate if needed */
425 	if (runtime->rate != 48000) {
426 		word = ac97c_readl(chip, MR);
427 		word |= AC97C_MR_VRA;
428 		ac97c_writel(chip, MR, word);
429 	} else {
430 		word = ac97c_readl(chip, MR);
431 		word &= ~(AC97C_MR_VRA);
432 		ac97c_writel(chip, MR, word);
433 	}
434 
435 	retval = snd_ac97_set_rate(chip->ac97, AC97_PCM_LR_ADC_RATE,
436 			runtime->rate);
437 	if (retval)
438 		dev_dbg(&chip->pdev->dev, "could not set rate %d Hz\n",
439 				runtime->rate);
440 
441 	if (!test_bit(DMA_RX_READY, &chip->flags))
442 		retval = atmel_ac97c_prepare_dma(chip, substream,
443 				DMA_FROM_DEVICE);
444 
445 	return retval;
446 }
447 
448 static int
449 atmel_ac97c_playback_trigger(struct snd_pcm_substream *substream, int cmd)
450 {
451 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
452 	unsigned long camr;
453 	int retval = 0;
454 
455 	camr = ac97c_readl(chip, CAMR);
456 
457 	switch (cmd) {
458 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: /* fall through */
459 	case SNDRV_PCM_TRIGGER_RESUME: /* fall through */
460 	case SNDRV_PCM_TRIGGER_START:
461 		retval = dw_dma_cyclic_start(chip->dma.tx_chan);
462 		if (retval)
463 			goto out;
464 		camr |= AC97C_CMR_CENA;
465 		break;
466 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH: /* fall through */
467 	case SNDRV_PCM_TRIGGER_SUSPEND: /* fall through */
468 	case SNDRV_PCM_TRIGGER_STOP:
469 		dw_dma_cyclic_stop(chip->dma.tx_chan);
470 		if (chip->opened <= 1)
471 			camr &= ~AC97C_CMR_CENA;
472 		break;
473 	default:
474 		retval = -EINVAL;
475 		goto out;
476 	}
477 
478 	ac97c_writel(chip, CAMR, camr);
479 out:
480 	return retval;
481 }
482 
483 static int
484 atmel_ac97c_capture_trigger(struct snd_pcm_substream *substream, int cmd)
485 {
486 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
487 	unsigned long camr;
488 	int retval = 0;
489 
490 	camr = ac97c_readl(chip, CAMR);
491 
492 	switch (cmd) {
493 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: /* fall through */
494 	case SNDRV_PCM_TRIGGER_RESUME: /* fall through */
495 	case SNDRV_PCM_TRIGGER_START:
496 		retval = dw_dma_cyclic_start(chip->dma.rx_chan);
497 		if (retval)
498 			goto out;
499 		camr |= AC97C_CMR_CENA;
500 		break;
501 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH: /* fall through */
502 	case SNDRV_PCM_TRIGGER_SUSPEND: /* fall through */
503 	case SNDRV_PCM_TRIGGER_STOP:
504 		dw_dma_cyclic_stop(chip->dma.rx_chan);
505 		if (chip->opened <= 1)
506 			camr &= ~AC97C_CMR_CENA;
507 		break;
508 	default:
509 		retval = -EINVAL;
510 		break;
511 	}
512 
513 	ac97c_writel(chip, CAMR, camr);
514 out:
515 	return retval;
516 }
517 
518 static snd_pcm_uframes_t
519 atmel_ac97c_playback_pointer(struct snd_pcm_substream *substream)
520 {
521 	struct atmel_ac97c	*chip = snd_pcm_substream_chip(substream);
522 	struct snd_pcm_runtime	*runtime = substream->runtime;
523 	snd_pcm_uframes_t	frames;
524 	unsigned long		bytes;
525 
526 	bytes = dw_dma_get_src_addr(chip->dma.tx_chan);
527 	bytes -= runtime->dma_addr;
528 
529 	frames = bytes_to_frames(runtime, bytes);
530 	if (frames >= runtime->buffer_size)
531 		frames -= runtime->buffer_size;
532 	return frames;
533 }
534 
535 static snd_pcm_uframes_t
536 atmel_ac97c_capture_pointer(struct snd_pcm_substream *substream)
537 {
538 	struct atmel_ac97c	*chip = snd_pcm_substream_chip(substream);
539 	struct snd_pcm_runtime	*runtime = substream->runtime;
540 	snd_pcm_uframes_t	frames;
541 	unsigned long		bytes;
542 
543 	bytes = dw_dma_get_dst_addr(chip->dma.rx_chan);
544 	bytes -= runtime->dma_addr;
545 
546 	frames = bytes_to_frames(runtime, bytes);
547 	if (frames >= runtime->buffer_size)
548 		frames -= runtime->buffer_size;
549 	return frames;
550 }
551 
552 static struct snd_pcm_ops atmel_ac97_playback_ops = {
553 	.open		= atmel_ac97c_playback_open,
554 	.close		= atmel_ac97c_playback_close,
555 	.ioctl		= snd_pcm_lib_ioctl,
556 	.hw_params	= atmel_ac97c_playback_hw_params,
557 	.hw_free	= atmel_ac97c_playback_hw_free,
558 	.prepare	= atmel_ac97c_playback_prepare,
559 	.trigger	= atmel_ac97c_playback_trigger,
560 	.pointer	= atmel_ac97c_playback_pointer,
561 };
562 
563 static struct snd_pcm_ops atmel_ac97_capture_ops = {
564 	.open		= atmel_ac97c_capture_open,
565 	.close		= atmel_ac97c_capture_close,
566 	.ioctl		= snd_pcm_lib_ioctl,
567 	.hw_params	= atmel_ac97c_capture_hw_params,
568 	.hw_free	= atmel_ac97c_capture_hw_free,
569 	.prepare	= atmel_ac97c_capture_prepare,
570 	.trigger	= atmel_ac97c_capture_trigger,
571 	.pointer	= atmel_ac97c_capture_pointer,
572 };
573 
574 static irqreturn_t atmel_ac97c_interrupt(int irq, void *dev)
575 {
576 	struct atmel_ac97c	*chip  = (struct atmel_ac97c *)dev;
577 	irqreturn_t		retval = IRQ_NONE;
578 	u32			sr     = ac97c_readl(chip, SR);
579 	u32			casr   = ac97c_readl(chip, CASR);
580 	u32			cosr   = ac97c_readl(chip, COSR);
581 
582 	if (sr & AC97C_SR_CAEVT) {
583 		dev_info(&chip->pdev->dev, "channel A event%s%s%s%s%s%s\n",
584 				casr & AC97C_CSR_OVRUN   ? " OVRUN"   : "",
585 				casr & AC97C_CSR_RXRDY   ? " RXRDY"   : "",
586 				casr & AC97C_CSR_UNRUN   ? " UNRUN"   : "",
587 				casr & AC97C_CSR_TXEMPTY ? " TXEMPTY" : "",
588 				casr & AC97C_CSR_TXRDY   ? " TXRDY"   : "",
589 				!casr                    ? " NONE"    : "");
590 		retval = IRQ_HANDLED;
591 	}
592 
593 	if (sr & AC97C_SR_COEVT) {
594 		dev_info(&chip->pdev->dev, "codec channel event%s%s%s%s%s\n",
595 				cosr & AC97C_CSR_OVRUN   ? " OVRUN"   : "",
596 				cosr & AC97C_CSR_RXRDY   ? " RXRDY"   : "",
597 				cosr & AC97C_CSR_TXEMPTY ? " TXEMPTY" : "",
598 				cosr & AC97C_CSR_TXRDY   ? " TXRDY"   : "",
599 				!cosr                    ? " NONE"    : "");
600 		retval = IRQ_HANDLED;
601 	}
602 
603 	if (retval == IRQ_NONE) {
604 		dev_err(&chip->pdev->dev, "spurious interrupt sr 0x%08x "
605 				"casr 0x%08x cosr 0x%08x\n", sr, casr, cosr);
606 	}
607 
608 	return retval;
609 }
610 
611 static int __devinit atmel_ac97c_pcm_new(struct atmel_ac97c *chip)
612 {
613 	struct snd_pcm		*pcm;
614 	struct snd_pcm_hardware	hw = atmel_ac97c_hw;
615 	int			capture, playback, retval;
616 
617 	capture = test_bit(DMA_RX_CHAN_PRESENT, &chip->flags);
618 	playback = test_bit(DMA_TX_CHAN_PRESENT, &chip->flags);
619 
620 	retval = snd_pcm_new(chip->card, chip->card->shortname,
621 			chip->pdev->id, playback, capture, &pcm);
622 	if (retval)
623 		return retval;
624 
625 	if (capture)
626 		snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE,
627 				&atmel_ac97_capture_ops);
628 	if (playback)
629 		snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK,
630 				&atmel_ac97_playback_ops);
631 
632 	retval = snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
633 			&chip->pdev->dev, hw.periods_min * hw.period_bytes_min,
634 			hw.buffer_bytes_max);
635 	if (retval)
636 		return retval;
637 
638 	pcm->private_data = chip;
639 	pcm->info_flags = 0;
640 	strcpy(pcm->name, chip->card->shortname);
641 	chip->pcm = pcm;
642 
643 	return 0;
644 }
645 
646 static int atmel_ac97c_mixer_new(struct atmel_ac97c *chip)
647 {
648 	struct snd_ac97_template template;
649 	memset(&template, 0, sizeof(template));
650 	template.private_data = chip;
651 	return snd_ac97_mixer(chip->ac97_bus, &template, &chip->ac97);
652 }
653 
654 static void atmel_ac97c_write(struct snd_ac97 *ac97, unsigned short reg,
655 		unsigned short val)
656 {
657 	struct atmel_ac97c *chip = get_chip(ac97);
658 	unsigned long word;
659 	int timeout = 40;
660 
661 	word = (reg & 0x7f) << 16 | val;
662 
663 	do {
664 		if (ac97c_readl(chip, COSR) & AC97C_CSR_TXRDY) {
665 			ac97c_writel(chip, COTHR, word);
666 			return;
667 		}
668 		udelay(1);
669 	} while (--timeout);
670 
671 	dev_dbg(&chip->pdev->dev, "codec write timeout\n");
672 }
673 
674 static unsigned short atmel_ac97c_read(struct snd_ac97 *ac97,
675 		unsigned short reg)
676 {
677 	struct atmel_ac97c *chip = get_chip(ac97);
678 	unsigned long word;
679 	int timeout = 40;
680 	int write = 10;
681 
682 	word = (0x80 | (reg & 0x7f)) << 16;
683 
684 	if ((ac97c_readl(chip, COSR) & AC97C_CSR_RXRDY) != 0)
685 		ac97c_readl(chip, CORHR);
686 
687 retry_write:
688 	timeout = 40;
689 
690 	do {
691 		if ((ac97c_readl(chip, COSR) & AC97C_CSR_TXRDY) != 0) {
692 			ac97c_writel(chip, COTHR, word);
693 			goto read_reg;
694 		}
695 		udelay(10);
696 	} while (--timeout);
697 
698 	if (!--write)
699 		goto timed_out;
700 	goto retry_write;
701 
702 read_reg:
703 	do {
704 		if ((ac97c_readl(chip, COSR) & AC97C_CSR_RXRDY) != 0) {
705 			unsigned short val = ac97c_readl(chip, CORHR);
706 			return val;
707 		}
708 		udelay(10);
709 	} while (--timeout);
710 
711 	if (!--write)
712 		goto timed_out;
713 	goto retry_write;
714 
715 timed_out:
716 	dev_dbg(&chip->pdev->dev, "codec read timeout\n");
717 	return 0xffff;
718 }
719 
720 static bool filter(struct dma_chan *chan, void *slave)
721 {
722 	struct dw_dma_slave *dws = slave;
723 
724 	if (dws->dma_dev == chan->device->dev) {
725 		chan->private = dws;
726 		return true;
727 	} else
728 		return false;
729 }
730 
731 static void atmel_ac97c_reset(struct atmel_ac97c *chip)
732 {
733 	ac97c_writel(chip, MR,   0);
734 	ac97c_writel(chip, MR,   AC97C_MR_ENA);
735 	ac97c_writel(chip, CAMR, 0);
736 	ac97c_writel(chip, COMR, 0);
737 
738 	if (gpio_is_valid(chip->reset_pin)) {
739 		gpio_set_value(chip->reset_pin, 0);
740 		/* AC97 v2.2 specifications says minimum 1 us. */
741 		udelay(2);
742 		gpio_set_value(chip->reset_pin, 1);
743 	}
744 }
745 
746 static int __devinit atmel_ac97c_probe(struct platform_device *pdev)
747 {
748 	struct snd_card			*card;
749 	struct atmel_ac97c		*chip;
750 	struct resource			*regs;
751 	struct ac97c_platform_data	*pdata;
752 	struct clk			*pclk;
753 	static struct snd_ac97_bus_ops	ops = {
754 		.write	= atmel_ac97c_write,
755 		.read	= atmel_ac97c_read,
756 	};
757 	int				retval;
758 	int				irq;
759 
760 	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
761 	if (!regs) {
762 		dev_dbg(&pdev->dev, "no memory resource\n");
763 		return -ENXIO;
764 	}
765 
766 	pdata = pdev->dev.platform_data;
767 	if (!pdata) {
768 		dev_dbg(&pdev->dev, "no platform data\n");
769 		return -ENXIO;
770 	}
771 
772 	irq = platform_get_irq(pdev, 0);
773 	if (irq < 0) {
774 		dev_dbg(&pdev->dev, "could not get irq\n");
775 		return -ENXIO;
776 	}
777 
778 	pclk = clk_get(&pdev->dev, "pclk");
779 	if (IS_ERR(pclk)) {
780 		dev_dbg(&pdev->dev, "no peripheral clock\n");
781 		return PTR_ERR(pclk);
782 	}
783 	clk_enable(pclk);
784 
785 	retval = snd_card_create(SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1,
786 			THIS_MODULE, sizeof(struct atmel_ac97c), &card);
787 	if (retval) {
788 		dev_dbg(&pdev->dev, "could not create sound card device\n");
789 		goto err_snd_card_new;
790 	}
791 
792 	chip = get_chip(card);
793 
794 	retval = request_irq(irq, atmel_ac97c_interrupt, 0, "AC97C", chip);
795 	if (retval) {
796 		dev_dbg(&pdev->dev, "unable to request irq %d\n", irq);
797 		goto err_request_irq;
798 	}
799 	chip->irq = irq;
800 
801 	spin_lock_init(&chip->lock);
802 
803 	strcpy(card->driver, "Atmel AC97C");
804 	strcpy(card->shortname, "Atmel AC97C");
805 	sprintf(card->longname, "Atmel AC97 controller");
806 
807 	chip->card = card;
808 	chip->pclk = pclk;
809 	chip->pdev = pdev;
810 	chip->regs = ioremap(regs->start, regs->end - regs->start + 1);
811 
812 	if (!chip->regs) {
813 		dev_dbg(&pdev->dev, "could not remap register memory\n");
814 		goto err_ioremap;
815 	}
816 
817 	if (gpio_is_valid(pdata->reset_pin)) {
818 		if (gpio_request(pdata->reset_pin, "reset_pin")) {
819 			dev_dbg(&pdev->dev, "reset pin not available\n");
820 			chip->reset_pin = -ENODEV;
821 		} else {
822 			gpio_direction_output(pdata->reset_pin, 1);
823 			chip->reset_pin = pdata->reset_pin;
824 		}
825 	}
826 
827 	snd_card_set_dev(card, &pdev->dev);
828 
829 	atmel_ac97c_reset(chip);
830 
831 	/* Enable overrun interrupt from codec channel */
832 	ac97c_writel(chip, COMR, AC97C_CSR_OVRUN);
833 	ac97c_writel(chip, IER, ac97c_readl(chip, IMR) | AC97C_SR_COEVT);
834 
835 	retval = snd_ac97_bus(card, 0, &ops, chip, &chip->ac97_bus);
836 	if (retval) {
837 		dev_dbg(&pdev->dev, "could not register on ac97 bus\n");
838 		goto err_ac97_bus;
839 	}
840 
841 	retval = atmel_ac97c_mixer_new(chip);
842 	if (retval) {
843 		dev_dbg(&pdev->dev, "could not register ac97 mixer\n");
844 		goto err_ac97_bus;
845 	}
846 
847 	if (pdata->rx_dws.dma_dev) {
848 		struct dw_dma_slave *dws = &pdata->rx_dws;
849 		dma_cap_mask_t mask;
850 
851 		dws->rx_reg = regs->start + AC97C_CARHR + 2;
852 
853 		dma_cap_zero(mask);
854 		dma_cap_set(DMA_SLAVE, mask);
855 
856 		chip->dma.rx_chan = dma_request_channel(mask, filter, dws);
857 
858 		dev_info(&chip->pdev->dev, "using %s for DMA RX\n",
859 				dev_name(&chip->dma.rx_chan->dev->device));
860 		set_bit(DMA_RX_CHAN_PRESENT, &chip->flags);
861 	}
862 
863 	if (pdata->tx_dws.dma_dev) {
864 		struct dw_dma_slave *dws = &pdata->tx_dws;
865 		dma_cap_mask_t mask;
866 
867 		dws->tx_reg = regs->start + AC97C_CATHR + 2;
868 
869 		dma_cap_zero(mask);
870 		dma_cap_set(DMA_SLAVE, mask);
871 
872 		chip->dma.tx_chan = dma_request_channel(mask, filter, dws);
873 
874 		dev_info(&chip->pdev->dev, "using %s for DMA TX\n",
875 				dev_name(&chip->dma.tx_chan->dev->device));
876 		set_bit(DMA_TX_CHAN_PRESENT, &chip->flags);
877 	}
878 
879 	if (!test_bit(DMA_RX_CHAN_PRESENT, &chip->flags) &&
880 			!test_bit(DMA_TX_CHAN_PRESENT, &chip->flags)) {
881 		dev_dbg(&pdev->dev, "DMA not available\n");
882 		retval = -ENODEV;
883 		goto err_dma;
884 	}
885 
886 	retval = atmel_ac97c_pcm_new(chip);
887 	if (retval) {
888 		dev_dbg(&pdev->dev, "could not register ac97 pcm device\n");
889 		goto err_dma;
890 	}
891 
892 	retval = snd_card_register(card);
893 	if (retval) {
894 		dev_dbg(&pdev->dev, "could not register sound card\n");
895 		goto err_dma;
896 	}
897 
898 	platform_set_drvdata(pdev, card);
899 
900 	dev_info(&pdev->dev, "Atmel AC97 controller at 0x%p\n",
901 			chip->regs);
902 
903 	return 0;
904 
905 err_dma:
906 	if (test_bit(DMA_RX_CHAN_PRESENT, &chip->flags))
907 		dma_release_channel(chip->dma.rx_chan);
908 	if (test_bit(DMA_TX_CHAN_PRESENT, &chip->flags))
909 		dma_release_channel(chip->dma.tx_chan);
910 	clear_bit(DMA_RX_CHAN_PRESENT, &chip->flags);
911 	clear_bit(DMA_TX_CHAN_PRESENT, &chip->flags);
912 	chip->dma.rx_chan = NULL;
913 	chip->dma.tx_chan = NULL;
914 err_ac97_bus:
915 	snd_card_set_dev(card, NULL);
916 
917 	if (gpio_is_valid(chip->reset_pin))
918 		gpio_free(chip->reset_pin);
919 
920 	iounmap(chip->regs);
921 err_ioremap:
922 	free_irq(irq, chip);
923 err_request_irq:
924 	snd_card_free(card);
925 err_snd_card_new:
926 	clk_disable(pclk);
927 	clk_put(pclk);
928 	return retval;
929 }
930 
931 #ifdef CONFIG_PM
932 static int atmel_ac97c_suspend(struct platform_device *pdev, pm_message_t msg)
933 {
934 	struct snd_card *card = platform_get_drvdata(pdev);
935 	struct atmel_ac97c *chip = card->private_data;
936 
937 	if (test_bit(DMA_RX_READY, &chip->flags))
938 		dw_dma_cyclic_stop(chip->dma.rx_chan);
939 	if (test_bit(DMA_TX_READY, &chip->flags))
940 		dw_dma_cyclic_stop(chip->dma.tx_chan);
941 	clk_disable(chip->pclk);
942 
943 	return 0;
944 }
945 
946 static int atmel_ac97c_resume(struct platform_device *pdev)
947 {
948 	struct snd_card *card = platform_get_drvdata(pdev);
949 	struct atmel_ac97c *chip = card->private_data;
950 
951 	clk_enable(chip->pclk);
952 	if (test_bit(DMA_RX_READY, &chip->flags))
953 		dw_dma_cyclic_start(chip->dma.rx_chan);
954 	if (test_bit(DMA_TX_READY, &chip->flags))
955 		dw_dma_cyclic_start(chip->dma.tx_chan);
956 
957 	return 0;
958 }
959 #else
960 #define atmel_ac97c_suspend NULL
961 #define atmel_ac97c_resume NULL
962 #endif
963 
964 static int __devexit atmel_ac97c_remove(struct platform_device *pdev)
965 {
966 	struct snd_card *card = platform_get_drvdata(pdev);
967 	struct atmel_ac97c *chip = get_chip(card);
968 
969 	if (gpio_is_valid(chip->reset_pin))
970 		gpio_free(chip->reset_pin);
971 
972 	ac97c_writel(chip, CAMR, 0);
973 	ac97c_writel(chip, COMR, 0);
974 	ac97c_writel(chip, MR,   0);
975 
976 	clk_disable(chip->pclk);
977 	clk_put(chip->pclk);
978 	iounmap(chip->regs);
979 	free_irq(chip->irq, chip);
980 
981 	if (test_bit(DMA_RX_CHAN_PRESENT, &chip->flags))
982 		dma_release_channel(chip->dma.rx_chan);
983 	if (test_bit(DMA_TX_CHAN_PRESENT, &chip->flags))
984 		dma_release_channel(chip->dma.tx_chan);
985 	clear_bit(DMA_RX_CHAN_PRESENT, &chip->flags);
986 	clear_bit(DMA_TX_CHAN_PRESENT, &chip->flags);
987 	chip->dma.rx_chan = NULL;
988 	chip->dma.tx_chan = NULL;
989 
990 	snd_card_set_dev(card, NULL);
991 	snd_card_free(card);
992 
993 	platform_set_drvdata(pdev, NULL);
994 
995 	return 0;
996 }
997 
998 static struct platform_driver atmel_ac97c_driver = {
999 	.remove		= __devexit_p(atmel_ac97c_remove),
1000 	.driver		= {
1001 		.name	= "atmel_ac97c",
1002 	},
1003 	.suspend	= atmel_ac97c_suspend,
1004 	.resume		= atmel_ac97c_resume,
1005 };
1006 
1007 static int __init atmel_ac97c_init(void)
1008 {
1009 	return platform_driver_probe(&atmel_ac97c_driver,
1010 			atmel_ac97c_probe);
1011 }
1012 module_init(atmel_ac97c_init);
1013 
1014 static void __exit atmel_ac97c_exit(void)
1015 {
1016 	platform_driver_unregister(&atmel_ac97c_driver);
1017 }
1018 module_exit(atmel_ac97c_exit);
1019 
1020 MODULE_LICENSE("GPL");
1021 MODULE_DESCRIPTION("Driver for Atmel AC97 controller");
1022 MODULE_AUTHOR("Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>");
1023