xref: /openbmc/linux/sound/atmel/ac97c.c (revision d89775fc)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Driver for Atmel AC97C
4  *
5  * Copyright (C) 2005-2009 Atmel Corporation
6  */
7 #include <linux/clk.h>
8 #include <linux/delay.h>
9 #include <linux/bitmap.h>
10 #include <linux/device.h>
11 #include <linux/atmel_pdc.h>
12 #include <linux/gpio/consumer.h>
13 #include <linux/init.h>
14 #include <linux/interrupt.h>
15 #include <linux/module.h>
16 #include <linux/platform_device.h>
17 #include <linux/mutex.h>
18 #include <linux/types.h>
19 #include <linux/io.h>
20 #include <linux/of.h>
21 #include <linux/of_device.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/memalloc.h>
29 
30 #include "ac97c.h"
31 
32 /* Serialize access to opened variable */
33 static DEFINE_MUTEX(opened_mutex);
34 
35 struct atmel_ac97c {
36 	struct clk			*pclk;
37 	struct platform_device		*pdev;
38 
39 	struct snd_pcm_substream	*playback_substream;
40 	struct snd_pcm_substream	*capture_substream;
41 	struct snd_card			*card;
42 	struct snd_pcm			*pcm;
43 	struct snd_ac97			*ac97;
44 	struct snd_ac97_bus		*ac97_bus;
45 
46 	u64				cur_format;
47 	unsigned int			cur_rate;
48 	int				playback_period, capture_period;
49 	/* Serialize access to opened variable */
50 	spinlock_t			lock;
51 	void __iomem			*regs;
52 	int				irq;
53 	int				opened;
54 	struct gpio_desc		*reset_pin;
55 };
56 
57 #define get_chip(card) ((struct atmel_ac97c *)(card)->private_data)
58 
59 #define ac97c_writel(chip, reg, val)			\
60 	__raw_writel((val), (chip)->regs + AC97C_##reg)
61 #define ac97c_readl(chip, reg)				\
62 	__raw_readl((chip)->regs + AC97C_##reg)
63 
64 static const struct snd_pcm_hardware atmel_ac97c_hw = {
65 	.info			= (SNDRV_PCM_INFO_MMAP
66 				  | SNDRV_PCM_INFO_MMAP_VALID
67 				  | SNDRV_PCM_INFO_INTERLEAVED
68 				  | SNDRV_PCM_INFO_BLOCK_TRANSFER
69 				  | SNDRV_PCM_INFO_JOINT_DUPLEX
70 				  | SNDRV_PCM_INFO_RESUME
71 				  | SNDRV_PCM_INFO_PAUSE),
72 	.formats		= (SNDRV_PCM_FMTBIT_S16_BE
73 				  | SNDRV_PCM_FMTBIT_S16_LE),
74 	.rates			= (SNDRV_PCM_RATE_CONTINUOUS),
75 	.rate_min		= 4000,
76 	.rate_max		= 48000,
77 	.channels_min		= 1,
78 	.channels_max		= 2,
79 	.buffer_bytes_max	= 2 * 2 * 64 * 2048,
80 	.period_bytes_min	= 4096,
81 	.period_bytes_max	= 4096,
82 	.periods_min		= 6,
83 	.periods_max		= 64,
84 };
85 
86 static int atmel_ac97c_playback_open(struct snd_pcm_substream *substream)
87 {
88 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
89 	struct snd_pcm_runtime *runtime = substream->runtime;
90 
91 	mutex_lock(&opened_mutex);
92 	chip->opened++;
93 	runtime->hw = atmel_ac97c_hw;
94 	if (chip->cur_rate) {
95 		runtime->hw.rate_min = chip->cur_rate;
96 		runtime->hw.rate_max = chip->cur_rate;
97 	}
98 	if (chip->cur_format)
99 		runtime->hw.formats = pcm_format_to_bits(chip->cur_format);
100 	mutex_unlock(&opened_mutex);
101 	chip->playback_substream = substream;
102 	return 0;
103 }
104 
105 static int atmel_ac97c_capture_open(struct snd_pcm_substream *substream)
106 {
107 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
108 	struct snd_pcm_runtime *runtime = substream->runtime;
109 
110 	mutex_lock(&opened_mutex);
111 	chip->opened++;
112 	runtime->hw = atmel_ac97c_hw;
113 	if (chip->cur_rate) {
114 		runtime->hw.rate_min = chip->cur_rate;
115 		runtime->hw.rate_max = chip->cur_rate;
116 	}
117 	if (chip->cur_format)
118 		runtime->hw.formats = pcm_format_to_bits(chip->cur_format);
119 	mutex_unlock(&opened_mutex);
120 	chip->capture_substream = substream;
121 	return 0;
122 }
123 
124 static int atmel_ac97c_playback_close(struct snd_pcm_substream *substream)
125 {
126 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
127 
128 	mutex_lock(&opened_mutex);
129 	chip->opened--;
130 	if (!chip->opened) {
131 		chip->cur_rate = 0;
132 		chip->cur_format = 0;
133 	}
134 	mutex_unlock(&opened_mutex);
135 
136 	chip->playback_substream = NULL;
137 
138 	return 0;
139 }
140 
141 static int atmel_ac97c_capture_close(struct snd_pcm_substream *substream)
142 {
143 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
144 
145 	mutex_lock(&opened_mutex);
146 	chip->opened--;
147 	if (!chip->opened) {
148 		chip->cur_rate = 0;
149 		chip->cur_format = 0;
150 	}
151 	mutex_unlock(&opened_mutex);
152 
153 	chip->capture_substream = NULL;
154 
155 	return 0;
156 }
157 
158 static int atmel_ac97c_playback_hw_params(struct snd_pcm_substream *substream,
159 		struct snd_pcm_hw_params *hw_params)
160 {
161 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
162 
163 	/* Set restrictions to params. */
164 	mutex_lock(&opened_mutex);
165 	chip->cur_rate = params_rate(hw_params);
166 	chip->cur_format = params_format(hw_params);
167 	mutex_unlock(&opened_mutex);
168 
169 	return 0;
170 }
171 
172 static int atmel_ac97c_capture_hw_params(struct snd_pcm_substream *substream,
173 		struct snd_pcm_hw_params *hw_params)
174 {
175 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
176 
177 	/* Set restrictions to params. */
178 	mutex_lock(&opened_mutex);
179 	chip->cur_rate = params_rate(hw_params);
180 	chip->cur_format = params_format(hw_params);
181 	mutex_unlock(&opened_mutex);
182 
183 	return 0;
184 }
185 
186 static int atmel_ac97c_playback_prepare(struct snd_pcm_substream *substream)
187 {
188 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
189 	struct snd_pcm_runtime *runtime = substream->runtime;
190 	int block_size = frames_to_bytes(runtime, runtime->period_size);
191 	unsigned long word = ac97c_readl(chip, OCA);
192 	int retval;
193 
194 	chip->playback_period = 0;
195 	word &= ~(AC97C_CH_MASK(PCM_LEFT) | AC97C_CH_MASK(PCM_RIGHT));
196 
197 	/* assign channels to AC97C channel A */
198 	switch (runtime->channels) {
199 	case 1:
200 		word |= AC97C_CH_ASSIGN(PCM_LEFT, A);
201 		break;
202 	case 2:
203 		word |= AC97C_CH_ASSIGN(PCM_LEFT, A)
204 			| AC97C_CH_ASSIGN(PCM_RIGHT, A);
205 		break;
206 	default:
207 		/* TODO: support more than two channels */
208 		return -EINVAL;
209 	}
210 	ac97c_writel(chip, OCA, word);
211 
212 	/* configure sample format and size */
213 	word = ac97c_readl(chip, CAMR);
214 	if (chip->opened <= 1)
215 		word = AC97C_CMR_DMAEN | AC97C_CMR_SIZE_16;
216 	else
217 		word |= AC97C_CMR_DMAEN | AC97C_CMR_SIZE_16;
218 
219 	switch (runtime->format) {
220 	case SNDRV_PCM_FORMAT_S16_LE:
221 		break;
222 	case SNDRV_PCM_FORMAT_S16_BE:
223 		word &= ~(AC97C_CMR_CEM_LITTLE);
224 		break;
225 	default:
226 		word = ac97c_readl(chip, OCA);
227 		word &= ~(AC97C_CH_MASK(PCM_LEFT) | AC97C_CH_MASK(PCM_RIGHT));
228 		ac97c_writel(chip, OCA, word);
229 		return -EINVAL;
230 	}
231 
232 	/* Enable underrun interrupt on channel A */
233 	word |= AC97C_CSR_UNRUN;
234 
235 	ac97c_writel(chip, CAMR, word);
236 
237 	/* Enable channel A event interrupt */
238 	word = ac97c_readl(chip, IMR);
239 	word |= AC97C_SR_CAEVT;
240 	ac97c_writel(chip, IER, word);
241 
242 	/* set variable rate if needed */
243 	if (runtime->rate != 48000) {
244 		word = ac97c_readl(chip, MR);
245 		word |= AC97C_MR_VRA;
246 		ac97c_writel(chip, MR, word);
247 	} else {
248 		word = ac97c_readl(chip, MR);
249 		word &= ~(AC97C_MR_VRA);
250 		ac97c_writel(chip, MR, word);
251 	}
252 
253 	retval = snd_ac97_set_rate(chip->ac97, AC97_PCM_FRONT_DAC_RATE,
254 			runtime->rate);
255 	if (retval)
256 		dev_dbg(&chip->pdev->dev, "could not set rate %d Hz\n",
257 				runtime->rate);
258 
259 	/* Initialize and start the PDC */
260 	writel(runtime->dma_addr, chip->regs + ATMEL_PDC_TPR);
261 	writel(block_size / 2, chip->regs + ATMEL_PDC_TCR);
262 	writel(runtime->dma_addr + block_size, chip->regs + ATMEL_PDC_TNPR);
263 	writel(block_size / 2, chip->regs + ATMEL_PDC_TNCR);
264 
265 	return retval;
266 }
267 
268 static int atmel_ac97c_capture_prepare(struct snd_pcm_substream *substream)
269 {
270 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
271 	struct snd_pcm_runtime *runtime = substream->runtime;
272 	int block_size = frames_to_bytes(runtime, runtime->period_size);
273 	unsigned long word = ac97c_readl(chip, ICA);
274 	int retval;
275 
276 	chip->capture_period = 0;
277 	word &= ~(AC97C_CH_MASK(PCM_LEFT) | AC97C_CH_MASK(PCM_RIGHT));
278 
279 	/* assign channels to AC97C channel A */
280 	switch (runtime->channels) {
281 	case 1:
282 		word |= AC97C_CH_ASSIGN(PCM_LEFT, A);
283 		break;
284 	case 2:
285 		word |= AC97C_CH_ASSIGN(PCM_LEFT, A)
286 			| AC97C_CH_ASSIGN(PCM_RIGHT, A);
287 		break;
288 	default:
289 		/* TODO: support more than two channels */
290 		return -EINVAL;
291 	}
292 	ac97c_writel(chip, ICA, word);
293 
294 	/* configure sample format and size */
295 	word = ac97c_readl(chip, CAMR);
296 	if (chip->opened <= 1)
297 		word = AC97C_CMR_DMAEN | AC97C_CMR_SIZE_16;
298 	else
299 		word |= AC97C_CMR_DMAEN | AC97C_CMR_SIZE_16;
300 
301 	switch (runtime->format) {
302 	case SNDRV_PCM_FORMAT_S16_LE:
303 		break;
304 	case SNDRV_PCM_FORMAT_S16_BE:
305 		word &= ~(AC97C_CMR_CEM_LITTLE);
306 		break;
307 	default:
308 		word = ac97c_readl(chip, ICA);
309 		word &= ~(AC97C_CH_MASK(PCM_LEFT) | AC97C_CH_MASK(PCM_RIGHT));
310 		ac97c_writel(chip, ICA, word);
311 		return -EINVAL;
312 	}
313 
314 	/* Enable overrun interrupt on channel A */
315 	word |= AC97C_CSR_OVRUN;
316 
317 	ac97c_writel(chip, CAMR, word);
318 
319 	/* Enable channel A event interrupt */
320 	word = ac97c_readl(chip, IMR);
321 	word |= AC97C_SR_CAEVT;
322 	ac97c_writel(chip, IER, word);
323 
324 	/* set variable rate if needed */
325 	if (runtime->rate != 48000) {
326 		word = ac97c_readl(chip, MR);
327 		word |= AC97C_MR_VRA;
328 		ac97c_writel(chip, MR, word);
329 	} else {
330 		word = ac97c_readl(chip, MR);
331 		word &= ~(AC97C_MR_VRA);
332 		ac97c_writel(chip, MR, word);
333 	}
334 
335 	retval = snd_ac97_set_rate(chip->ac97, AC97_PCM_LR_ADC_RATE,
336 			runtime->rate);
337 	if (retval)
338 		dev_dbg(&chip->pdev->dev, "could not set rate %d Hz\n",
339 				runtime->rate);
340 
341 	/* Initialize and start the PDC */
342 	writel(runtime->dma_addr, chip->regs + ATMEL_PDC_RPR);
343 	writel(block_size / 2, chip->regs + ATMEL_PDC_RCR);
344 	writel(runtime->dma_addr + block_size, chip->regs + ATMEL_PDC_RNPR);
345 	writel(block_size / 2, chip->regs + ATMEL_PDC_RNCR);
346 
347 	return retval;
348 }
349 
350 static int
351 atmel_ac97c_playback_trigger(struct snd_pcm_substream *substream, int cmd)
352 {
353 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
354 	unsigned long camr, ptcr = 0;
355 
356 	camr = ac97c_readl(chip, CAMR);
357 
358 	switch (cmd) {
359 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
360 	case SNDRV_PCM_TRIGGER_RESUME:
361 	case SNDRV_PCM_TRIGGER_START:
362 		ptcr = ATMEL_PDC_TXTEN;
363 		camr |= AC97C_CMR_CENA | AC97C_CSR_ENDTX;
364 		break;
365 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
366 	case SNDRV_PCM_TRIGGER_SUSPEND:
367 	case SNDRV_PCM_TRIGGER_STOP:
368 		ptcr |= ATMEL_PDC_TXTDIS;
369 		if (chip->opened <= 1)
370 			camr &= ~AC97C_CMR_CENA;
371 		break;
372 	default:
373 		return -EINVAL;
374 	}
375 
376 	ac97c_writel(chip, CAMR, camr);
377 	writel(ptcr, chip->regs + ATMEL_PDC_PTCR);
378 	return 0;
379 }
380 
381 static int
382 atmel_ac97c_capture_trigger(struct snd_pcm_substream *substream, int cmd)
383 {
384 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
385 	unsigned long camr, ptcr = 0;
386 
387 	camr = ac97c_readl(chip, CAMR);
388 	ptcr = readl(chip->regs + ATMEL_PDC_PTSR);
389 
390 	switch (cmd) {
391 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
392 	case SNDRV_PCM_TRIGGER_RESUME:
393 	case SNDRV_PCM_TRIGGER_START:
394 		ptcr = ATMEL_PDC_RXTEN;
395 		camr |= AC97C_CMR_CENA | AC97C_CSR_ENDRX;
396 		break;
397 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
398 	case SNDRV_PCM_TRIGGER_SUSPEND:
399 	case SNDRV_PCM_TRIGGER_STOP:
400 		ptcr |= ATMEL_PDC_RXTDIS;
401 		if (chip->opened <= 1)
402 			camr &= ~AC97C_CMR_CENA;
403 		break;
404 	default:
405 		return -EINVAL;
406 	}
407 
408 	ac97c_writel(chip, CAMR, camr);
409 	writel(ptcr, chip->regs + ATMEL_PDC_PTCR);
410 	return 0;
411 }
412 
413 static snd_pcm_uframes_t
414 atmel_ac97c_playback_pointer(struct snd_pcm_substream *substream)
415 {
416 	struct atmel_ac97c	*chip = snd_pcm_substream_chip(substream);
417 	struct snd_pcm_runtime	*runtime = substream->runtime;
418 	snd_pcm_uframes_t	frames;
419 	unsigned long		bytes;
420 
421 	bytes = readl(chip->regs + ATMEL_PDC_TPR);
422 	bytes -= runtime->dma_addr;
423 
424 	frames = bytes_to_frames(runtime, bytes);
425 	if (frames >= runtime->buffer_size)
426 		frames -= runtime->buffer_size;
427 	return frames;
428 }
429 
430 static snd_pcm_uframes_t
431 atmel_ac97c_capture_pointer(struct snd_pcm_substream *substream)
432 {
433 	struct atmel_ac97c	*chip = snd_pcm_substream_chip(substream);
434 	struct snd_pcm_runtime	*runtime = substream->runtime;
435 	snd_pcm_uframes_t	frames;
436 	unsigned long		bytes;
437 
438 	bytes = readl(chip->regs + ATMEL_PDC_RPR);
439 	bytes -= runtime->dma_addr;
440 
441 	frames = bytes_to_frames(runtime, bytes);
442 	if (frames >= runtime->buffer_size)
443 		frames -= runtime->buffer_size;
444 	return frames;
445 }
446 
447 static const struct snd_pcm_ops atmel_ac97_playback_ops = {
448 	.open		= atmel_ac97c_playback_open,
449 	.close		= atmel_ac97c_playback_close,
450 	.hw_params	= atmel_ac97c_playback_hw_params,
451 	.prepare	= atmel_ac97c_playback_prepare,
452 	.trigger	= atmel_ac97c_playback_trigger,
453 	.pointer	= atmel_ac97c_playback_pointer,
454 };
455 
456 static const struct snd_pcm_ops atmel_ac97_capture_ops = {
457 	.open		= atmel_ac97c_capture_open,
458 	.close		= atmel_ac97c_capture_close,
459 	.hw_params	= atmel_ac97c_capture_hw_params,
460 	.prepare	= atmel_ac97c_capture_prepare,
461 	.trigger	= atmel_ac97c_capture_trigger,
462 	.pointer	= atmel_ac97c_capture_pointer,
463 };
464 
465 static irqreturn_t atmel_ac97c_interrupt(int irq, void *dev)
466 {
467 	struct atmel_ac97c	*chip  = (struct atmel_ac97c *)dev;
468 	irqreturn_t		retval = IRQ_NONE;
469 	u32			sr     = ac97c_readl(chip, SR);
470 	u32			casr   = ac97c_readl(chip, CASR);
471 	u32			cosr   = ac97c_readl(chip, COSR);
472 	u32			camr   = ac97c_readl(chip, CAMR);
473 
474 	if (sr & AC97C_SR_CAEVT) {
475 		struct snd_pcm_runtime *runtime;
476 		int offset, next_period, block_size;
477 		dev_dbg(&chip->pdev->dev, "channel A event%s%s%s%s%s%s\n",
478 				casr & AC97C_CSR_OVRUN   ? " OVRUN"   : "",
479 				casr & AC97C_CSR_RXRDY   ? " RXRDY"   : "",
480 				casr & AC97C_CSR_UNRUN   ? " UNRUN"   : "",
481 				casr & AC97C_CSR_TXEMPTY ? " TXEMPTY" : "",
482 				casr & AC97C_CSR_TXRDY   ? " TXRDY"   : "",
483 				!casr                    ? " NONE"    : "");
484 		if ((casr & camr) & AC97C_CSR_ENDTX) {
485 			runtime = chip->playback_substream->runtime;
486 			block_size = frames_to_bytes(runtime, runtime->period_size);
487 			chip->playback_period++;
488 
489 			if (chip->playback_period == runtime->periods)
490 				chip->playback_period = 0;
491 			next_period = chip->playback_period + 1;
492 			if (next_period == runtime->periods)
493 				next_period = 0;
494 
495 			offset = block_size * next_period;
496 
497 			writel(runtime->dma_addr + offset, chip->regs + ATMEL_PDC_TNPR);
498 			writel(block_size / 2, chip->regs + ATMEL_PDC_TNCR);
499 
500 			snd_pcm_period_elapsed(chip->playback_substream);
501 		}
502 		if ((casr & camr) & AC97C_CSR_ENDRX) {
503 			runtime = chip->capture_substream->runtime;
504 			block_size = frames_to_bytes(runtime, runtime->period_size);
505 			chip->capture_period++;
506 
507 			if (chip->capture_period == runtime->periods)
508 				chip->capture_period = 0;
509 			next_period = chip->capture_period + 1;
510 			if (next_period == runtime->periods)
511 				next_period = 0;
512 
513 			offset = block_size * next_period;
514 
515 			writel(runtime->dma_addr + offset, chip->regs + ATMEL_PDC_RNPR);
516 			writel(block_size / 2, chip->regs + ATMEL_PDC_RNCR);
517 			snd_pcm_period_elapsed(chip->capture_substream);
518 		}
519 		retval = IRQ_HANDLED;
520 	}
521 
522 	if (sr & AC97C_SR_COEVT) {
523 		dev_info(&chip->pdev->dev, "codec channel event%s%s%s%s%s\n",
524 				cosr & AC97C_CSR_OVRUN   ? " OVRUN"   : "",
525 				cosr & AC97C_CSR_RXRDY   ? " RXRDY"   : "",
526 				cosr & AC97C_CSR_TXEMPTY ? " TXEMPTY" : "",
527 				cosr & AC97C_CSR_TXRDY   ? " TXRDY"   : "",
528 				!cosr                    ? " NONE"    : "");
529 		retval = IRQ_HANDLED;
530 	}
531 
532 	if (retval == IRQ_NONE) {
533 		dev_err(&chip->pdev->dev, "spurious interrupt sr 0x%08x "
534 				"casr 0x%08x cosr 0x%08x\n", sr, casr, cosr);
535 	}
536 
537 	return retval;
538 }
539 
540 static const struct ac97_pcm at91_ac97_pcm_defs[] = {
541 	/* Playback */
542 	{
543 		.exclusive = 1,
544 		.r = { {
545 			.slots = ((1 << AC97_SLOT_PCM_LEFT)
546 				  | (1 << AC97_SLOT_PCM_RIGHT)),
547 		} },
548 	},
549 	/* PCM in */
550 	{
551 		.stream = 1,
552 		.exclusive = 1,
553 		.r = { {
554 			.slots = ((1 << AC97_SLOT_PCM_LEFT)
555 					| (1 << AC97_SLOT_PCM_RIGHT)),
556 		} }
557 	},
558 	/* Mic in */
559 	{
560 		.stream = 1,
561 		.exclusive = 1,
562 		.r = { {
563 			.slots = (1<<AC97_SLOT_MIC),
564 		} }
565 	},
566 };
567 
568 static int atmel_ac97c_pcm_new(struct atmel_ac97c *chip)
569 {
570 	struct snd_pcm		*pcm;
571 	struct snd_pcm_hardware	hw = atmel_ac97c_hw;
572 	int			retval;
573 
574 	retval = snd_ac97_pcm_assign(chip->ac97_bus,
575 				     ARRAY_SIZE(at91_ac97_pcm_defs),
576 				     at91_ac97_pcm_defs);
577 	if (retval)
578 		return retval;
579 
580 	retval = snd_pcm_new(chip->card, chip->card->shortname, 0, 1, 1, &pcm);
581 	if (retval)
582 		return retval;
583 
584 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &atmel_ac97_capture_ops);
585 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &atmel_ac97_playback_ops);
586 
587 	snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV,
588 			&chip->pdev->dev, hw.periods_min * hw.period_bytes_min,
589 			hw.buffer_bytes_max);
590 
591 	pcm->private_data = chip;
592 	pcm->info_flags = 0;
593 	strcpy(pcm->name, chip->card->shortname);
594 	chip->pcm = pcm;
595 
596 	return 0;
597 }
598 
599 static int atmel_ac97c_mixer_new(struct atmel_ac97c *chip)
600 {
601 	struct snd_ac97_template template;
602 	memset(&template, 0, sizeof(template));
603 	template.private_data = chip;
604 	return snd_ac97_mixer(chip->ac97_bus, &template, &chip->ac97);
605 }
606 
607 static void atmel_ac97c_write(struct snd_ac97 *ac97, unsigned short reg,
608 		unsigned short val)
609 {
610 	struct atmel_ac97c *chip = get_chip(ac97);
611 	unsigned long word;
612 	int timeout = 40;
613 
614 	word = (reg & 0x7f) << 16 | val;
615 
616 	do {
617 		if (ac97c_readl(chip, COSR) & AC97C_CSR_TXRDY) {
618 			ac97c_writel(chip, COTHR, word);
619 			return;
620 		}
621 		udelay(1);
622 	} while (--timeout);
623 
624 	dev_dbg(&chip->pdev->dev, "codec write timeout\n");
625 }
626 
627 static unsigned short atmel_ac97c_read(struct snd_ac97 *ac97,
628 		unsigned short reg)
629 {
630 	struct atmel_ac97c *chip = get_chip(ac97);
631 	unsigned long word;
632 	int timeout = 40;
633 	int write = 10;
634 
635 	word = (0x80 | (reg & 0x7f)) << 16;
636 
637 	if ((ac97c_readl(chip, COSR) & AC97C_CSR_RXRDY) != 0)
638 		ac97c_readl(chip, CORHR);
639 
640 retry_write:
641 	timeout = 40;
642 
643 	do {
644 		if ((ac97c_readl(chip, COSR) & AC97C_CSR_TXRDY) != 0) {
645 			ac97c_writel(chip, COTHR, word);
646 			goto read_reg;
647 		}
648 		udelay(10);
649 	} while (--timeout);
650 
651 	if (!--write)
652 		goto timed_out;
653 	goto retry_write;
654 
655 read_reg:
656 	do {
657 		if ((ac97c_readl(chip, COSR) & AC97C_CSR_RXRDY) != 0) {
658 			unsigned short val = ac97c_readl(chip, CORHR);
659 			return val;
660 		}
661 		udelay(10);
662 	} while (--timeout);
663 
664 	if (!--write)
665 		goto timed_out;
666 	goto retry_write;
667 
668 timed_out:
669 	dev_dbg(&chip->pdev->dev, "codec read timeout\n");
670 	return 0xffff;
671 }
672 
673 static void atmel_ac97c_reset(struct atmel_ac97c *chip)
674 {
675 	ac97c_writel(chip, MR,   0);
676 	ac97c_writel(chip, MR,   AC97C_MR_ENA);
677 	ac97c_writel(chip, CAMR, 0);
678 	ac97c_writel(chip, COMR, 0);
679 
680 	if (!IS_ERR(chip->reset_pin)) {
681 		gpiod_set_value(chip->reset_pin, 0);
682 		/* AC97 v2.2 specifications says minimum 1 us. */
683 		udelay(2);
684 		gpiod_set_value(chip->reset_pin, 1);
685 	} else {
686 		ac97c_writel(chip, MR, AC97C_MR_WRST | AC97C_MR_ENA);
687 		udelay(2);
688 		ac97c_writel(chip, MR, AC97C_MR_ENA);
689 	}
690 }
691 
692 static const struct of_device_id atmel_ac97c_dt_ids[] = {
693 	{ .compatible = "atmel,at91sam9263-ac97c", },
694 	{ }
695 };
696 MODULE_DEVICE_TABLE(of, atmel_ac97c_dt_ids);
697 
698 static int atmel_ac97c_probe(struct platform_device *pdev)
699 {
700 	struct device			*dev = &pdev->dev;
701 	struct snd_card			*card;
702 	struct atmel_ac97c		*chip;
703 	struct resource			*regs;
704 	struct clk			*pclk;
705 	static const struct snd_ac97_bus_ops	ops = {
706 		.write	= atmel_ac97c_write,
707 		.read	= atmel_ac97c_read,
708 	};
709 	int				retval;
710 	int				irq;
711 
712 	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
713 	if (!regs) {
714 		dev_dbg(&pdev->dev, "no memory resource\n");
715 		return -ENXIO;
716 	}
717 
718 	irq = platform_get_irq(pdev, 0);
719 	if (irq < 0) {
720 		dev_dbg(&pdev->dev, "could not get irq: %d\n", irq);
721 		return irq;
722 	}
723 
724 	pclk = clk_get(&pdev->dev, "ac97_clk");
725 	if (IS_ERR(pclk)) {
726 		dev_dbg(&pdev->dev, "no peripheral clock\n");
727 		return PTR_ERR(pclk);
728 	}
729 	retval = clk_prepare_enable(pclk);
730 	if (retval)
731 		goto err_prepare_enable;
732 
733 	retval = snd_card_new(&pdev->dev, SNDRV_DEFAULT_IDX1,
734 			      SNDRV_DEFAULT_STR1, THIS_MODULE,
735 			      sizeof(struct atmel_ac97c), &card);
736 	if (retval) {
737 		dev_dbg(&pdev->dev, "could not create sound card device\n");
738 		goto err_snd_card_new;
739 	}
740 
741 	chip = get_chip(card);
742 
743 	retval = request_irq(irq, atmel_ac97c_interrupt, 0, "AC97C", chip);
744 	if (retval) {
745 		dev_dbg(&pdev->dev, "unable to request irq %d\n", irq);
746 		goto err_request_irq;
747 	}
748 	chip->irq = irq;
749 
750 	spin_lock_init(&chip->lock);
751 
752 	strcpy(card->driver, "Atmel AC97C");
753 	strcpy(card->shortname, "Atmel AC97C");
754 	sprintf(card->longname, "Atmel AC97 controller");
755 
756 	chip->card = card;
757 	chip->pclk = pclk;
758 	chip->pdev = pdev;
759 	chip->regs = ioremap(regs->start, resource_size(regs));
760 
761 	if (!chip->regs) {
762 		dev_dbg(&pdev->dev, "could not remap register memory\n");
763 		retval = -ENOMEM;
764 		goto err_ioremap;
765 	}
766 
767 	chip->reset_pin = devm_gpiod_get_index(dev, "ac97", 2, GPIOD_OUT_HIGH);
768 	if (IS_ERR(chip->reset_pin))
769 		dev_dbg(dev, "reset pin not available\n");
770 
771 	atmel_ac97c_reset(chip);
772 
773 	/* Enable overrun interrupt from codec channel */
774 	ac97c_writel(chip, COMR, AC97C_CSR_OVRUN);
775 	ac97c_writel(chip, IER, ac97c_readl(chip, IMR) | AC97C_SR_COEVT);
776 
777 	retval = snd_ac97_bus(card, 0, &ops, chip, &chip->ac97_bus);
778 	if (retval) {
779 		dev_dbg(&pdev->dev, "could not register on ac97 bus\n");
780 		goto err_ac97_bus;
781 	}
782 
783 	retval = atmel_ac97c_mixer_new(chip);
784 	if (retval) {
785 		dev_dbg(&pdev->dev, "could not register ac97 mixer\n");
786 		goto err_ac97_bus;
787 	}
788 
789 	retval = atmel_ac97c_pcm_new(chip);
790 	if (retval) {
791 		dev_dbg(&pdev->dev, "could not register ac97 pcm device\n");
792 		goto err_ac97_bus;
793 	}
794 
795 	retval = snd_card_register(card);
796 	if (retval) {
797 		dev_dbg(&pdev->dev, "could not register sound card\n");
798 		goto err_ac97_bus;
799 	}
800 
801 	platform_set_drvdata(pdev, card);
802 
803 	dev_info(&pdev->dev, "Atmel AC97 controller at 0x%p, irq = %d\n",
804 			chip->regs, irq);
805 
806 	return 0;
807 
808 err_ac97_bus:
809 	iounmap(chip->regs);
810 err_ioremap:
811 	free_irq(irq, chip);
812 err_request_irq:
813 	snd_card_free(card);
814 err_snd_card_new:
815 	clk_disable_unprepare(pclk);
816 err_prepare_enable:
817 	clk_put(pclk);
818 	return retval;
819 }
820 
821 #ifdef CONFIG_PM_SLEEP
822 static int atmel_ac97c_suspend(struct device *pdev)
823 {
824 	struct snd_card *card = dev_get_drvdata(pdev);
825 	struct atmel_ac97c *chip = card->private_data;
826 
827 	clk_disable_unprepare(chip->pclk);
828 	return 0;
829 }
830 
831 static int atmel_ac97c_resume(struct device *pdev)
832 {
833 	struct snd_card *card = dev_get_drvdata(pdev);
834 	struct atmel_ac97c *chip = card->private_data;
835 	int ret = clk_prepare_enable(chip->pclk);
836 
837 	return ret;
838 }
839 
840 static SIMPLE_DEV_PM_OPS(atmel_ac97c_pm, atmel_ac97c_suspend, atmel_ac97c_resume);
841 #define ATMEL_AC97C_PM_OPS	&atmel_ac97c_pm
842 #else
843 #define ATMEL_AC97C_PM_OPS	NULL
844 #endif
845 
846 static int atmel_ac97c_remove(struct platform_device *pdev)
847 {
848 	struct snd_card *card = platform_get_drvdata(pdev);
849 	struct atmel_ac97c *chip = get_chip(card);
850 
851 	ac97c_writel(chip, CAMR, 0);
852 	ac97c_writel(chip, COMR, 0);
853 	ac97c_writel(chip, MR,   0);
854 
855 	clk_disable_unprepare(chip->pclk);
856 	clk_put(chip->pclk);
857 	iounmap(chip->regs);
858 	free_irq(chip->irq, chip);
859 
860 	snd_card_free(card);
861 
862 	return 0;
863 }
864 
865 static struct platform_driver atmel_ac97c_driver = {
866 	.probe		= atmel_ac97c_probe,
867 	.remove		= atmel_ac97c_remove,
868 	.driver		= {
869 		.name	= "atmel_ac97c",
870 		.pm	= ATMEL_AC97C_PM_OPS,
871 		.of_match_table = atmel_ac97c_dt_ids,
872 	},
873 };
874 module_platform_driver(atmel_ac97c_driver);
875 
876 MODULE_LICENSE("GPL");
877 MODULE_DESCRIPTION("Driver for Atmel AC97 controller");
878 MODULE_AUTHOR("Hans-Christian Egtvedt <egtvedt@samfundet.no>");
879