xref: /linux/sound/atmel/ac97c.c (revision f884ab15afdc5514e88105c92a4e2e1e6539869a)
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/atmel_pdc.h>
17 #include <linux/init.h>
18 #include <linux/interrupt.h>
19 #include <linux/module.h>
20 #include <linux/platform_device.h>
21 #include <linux/mutex.h>
22 #include <linux/gpio.h>
23 #include <linux/types.h>
24 #include <linux/io.h>
25 
26 #include <sound/core.h>
27 #include <sound/initval.h>
28 #include <sound/pcm.h>
29 #include <sound/pcm_params.h>
30 #include <sound/ac97_codec.h>
31 #include <sound/atmel-ac97c.h>
32 #include <sound/memalloc.h>
33 
34 #include <linux/dw_dmac.h>
35 
36 #include <mach/cpu.h>
37 #include <mach/gpio.h>
38 
39 #ifdef CONFIG_ARCH_AT91
40 #include <mach/hardware.h>
41 #endif
42 
43 #include "ac97c.h"
44 
45 enum {
46 	DMA_TX_READY = 0,
47 	DMA_RX_READY,
48 	DMA_TX_CHAN_PRESENT,
49 	DMA_RX_CHAN_PRESENT,
50 };
51 
52 /* Serialize access to opened variable */
53 static DEFINE_MUTEX(opened_mutex);
54 
55 struct atmel_ac97c_dma {
56 	struct dma_chan			*rx_chan;
57 	struct dma_chan			*tx_chan;
58 };
59 
60 struct atmel_ac97c {
61 	struct clk			*pclk;
62 	struct platform_device		*pdev;
63 	struct atmel_ac97c_dma		dma;
64 
65 	struct snd_pcm_substream	*playback_substream;
66 	struct snd_pcm_substream	*capture_substream;
67 	struct snd_card			*card;
68 	struct snd_pcm			*pcm;
69 	struct snd_ac97			*ac97;
70 	struct snd_ac97_bus		*ac97_bus;
71 
72 	u64				cur_format;
73 	unsigned int			cur_rate;
74 	unsigned long			flags;
75 	int				playback_period, capture_period;
76 	/* Serialize access to opened variable */
77 	spinlock_t			lock;
78 	void __iomem			*regs;
79 	int				irq;
80 	int				opened;
81 	int				reset_pin;
82 };
83 
84 #define get_chip(card) ((struct atmel_ac97c *)(card)->private_data)
85 
86 #define ac97c_writel(chip, reg, val)			\
87 	__raw_writel((val), (chip)->regs + AC97C_##reg)
88 #define ac97c_readl(chip, reg)				\
89 	__raw_readl((chip)->regs + AC97C_##reg)
90 
91 /* This function is called by the DMA driver. */
92 static void atmel_ac97c_dma_playback_period_done(void *arg)
93 {
94 	struct atmel_ac97c *chip = arg;
95 	snd_pcm_period_elapsed(chip->playback_substream);
96 }
97 
98 static void atmel_ac97c_dma_capture_period_done(void *arg)
99 {
100 	struct atmel_ac97c *chip = arg;
101 	snd_pcm_period_elapsed(chip->capture_substream);
102 }
103 
104 static int atmel_ac97c_prepare_dma(struct atmel_ac97c *chip,
105 		struct snd_pcm_substream *substream,
106 		enum dma_transfer_direction direction)
107 {
108 	struct dma_chan			*chan;
109 	struct dw_cyclic_desc		*cdesc;
110 	struct snd_pcm_runtime		*runtime = substream->runtime;
111 	unsigned long			buffer_len, period_len;
112 
113 	/*
114 	 * We don't do DMA on "complex" transfers, i.e. with
115 	 * non-halfword-aligned buffers or lengths.
116 	 */
117 	if (runtime->dma_addr & 1 || runtime->buffer_size & 1) {
118 		dev_dbg(&chip->pdev->dev, "too complex transfer\n");
119 		return -EINVAL;
120 	}
121 
122 	if (direction == DMA_MEM_TO_DEV)
123 		chan = chip->dma.tx_chan;
124 	else
125 		chan = chip->dma.rx_chan;
126 
127 	buffer_len = frames_to_bytes(runtime, runtime->buffer_size);
128 	period_len = frames_to_bytes(runtime, runtime->period_size);
129 
130 	cdesc = dw_dma_cyclic_prep(chan, runtime->dma_addr, buffer_len,
131 			period_len, direction);
132 	if (IS_ERR(cdesc)) {
133 		dev_dbg(&chip->pdev->dev, "could not prepare cyclic DMA\n");
134 		return PTR_ERR(cdesc);
135 	}
136 
137 	if (direction == DMA_MEM_TO_DEV) {
138 		cdesc->period_callback = atmel_ac97c_dma_playback_period_done;
139 		set_bit(DMA_TX_READY, &chip->flags);
140 	} else {
141 		cdesc->period_callback = atmel_ac97c_dma_capture_period_done;
142 		set_bit(DMA_RX_READY, &chip->flags);
143 	}
144 
145 	cdesc->period_callback_param = chip;
146 
147 	return 0;
148 }
149 
150 static struct snd_pcm_hardware atmel_ac97c_hw = {
151 	.info			= (SNDRV_PCM_INFO_MMAP
152 				  | SNDRV_PCM_INFO_MMAP_VALID
153 				  | SNDRV_PCM_INFO_INTERLEAVED
154 				  | SNDRV_PCM_INFO_BLOCK_TRANSFER
155 				  | SNDRV_PCM_INFO_JOINT_DUPLEX
156 				  | SNDRV_PCM_INFO_RESUME
157 				  | SNDRV_PCM_INFO_PAUSE),
158 	.formats		= (SNDRV_PCM_FMTBIT_S16_BE
159 				  | SNDRV_PCM_FMTBIT_S16_LE),
160 	.rates			= (SNDRV_PCM_RATE_CONTINUOUS),
161 	.rate_min		= 4000,
162 	.rate_max		= 48000,
163 	.channels_min		= 1,
164 	.channels_max		= 2,
165 	.buffer_bytes_max	= 2 * 2 * 64 * 2048,
166 	.period_bytes_min	= 4096,
167 	.period_bytes_max	= 4096,
168 	.periods_min		= 6,
169 	.periods_max		= 64,
170 };
171 
172 static int atmel_ac97c_playback_open(struct snd_pcm_substream *substream)
173 {
174 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
175 	struct snd_pcm_runtime *runtime = substream->runtime;
176 
177 	mutex_lock(&opened_mutex);
178 	chip->opened++;
179 	runtime->hw = atmel_ac97c_hw;
180 	if (chip->cur_rate) {
181 		runtime->hw.rate_min = chip->cur_rate;
182 		runtime->hw.rate_max = chip->cur_rate;
183 	}
184 	if (chip->cur_format)
185 		runtime->hw.formats = pcm_format_to_bits(chip->cur_format);
186 	mutex_unlock(&opened_mutex);
187 	chip->playback_substream = substream;
188 	return 0;
189 }
190 
191 static int atmel_ac97c_capture_open(struct snd_pcm_substream *substream)
192 {
193 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
194 	struct snd_pcm_runtime *runtime = substream->runtime;
195 
196 	mutex_lock(&opened_mutex);
197 	chip->opened++;
198 	runtime->hw = atmel_ac97c_hw;
199 	if (chip->cur_rate) {
200 		runtime->hw.rate_min = chip->cur_rate;
201 		runtime->hw.rate_max = chip->cur_rate;
202 	}
203 	if (chip->cur_format)
204 		runtime->hw.formats = pcm_format_to_bits(chip->cur_format);
205 	mutex_unlock(&opened_mutex);
206 	chip->capture_substream = substream;
207 	return 0;
208 }
209 
210 static int atmel_ac97c_playback_close(struct snd_pcm_substream *substream)
211 {
212 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
213 
214 	mutex_lock(&opened_mutex);
215 	chip->opened--;
216 	if (!chip->opened) {
217 		chip->cur_rate = 0;
218 		chip->cur_format = 0;
219 	}
220 	mutex_unlock(&opened_mutex);
221 
222 	chip->playback_substream = NULL;
223 
224 	return 0;
225 }
226 
227 static int atmel_ac97c_capture_close(struct snd_pcm_substream *substream)
228 {
229 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
230 
231 	mutex_lock(&opened_mutex);
232 	chip->opened--;
233 	if (!chip->opened) {
234 		chip->cur_rate = 0;
235 		chip->cur_format = 0;
236 	}
237 	mutex_unlock(&opened_mutex);
238 
239 	chip->capture_substream = NULL;
240 
241 	return 0;
242 }
243 
244 static int atmel_ac97c_playback_hw_params(struct snd_pcm_substream *substream,
245 		struct snd_pcm_hw_params *hw_params)
246 {
247 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
248 	int retval;
249 
250 	retval = snd_pcm_lib_malloc_pages(substream,
251 					params_buffer_bytes(hw_params));
252 	if (retval < 0)
253 		return retval;
254 	/* snd_pcm_lib_malloc_pages returns 1 if buffer is changed. */
255 	if (cpu_is_at32ap7000()) {
256 		/* snd_pcm_lib_malloc_pages returns 1 if buffer is changed. */
257 		if (retval == 1)
258 			if (test_and_clear_bit(DMA_TX_READY, &chip->flags))
259 				dw_dma_cyclic_free(chip->dma.tx_chan);
260 	}
261 	/* Set restrictions to params. */
262 	mutex_lock(&opened_mutex);
263 	chip->cur_rate = params_rate(hw_params);
264 	chip->cur_format = params_format(hw_params);
265 	mutex_unlock(&opened_mutex);
266 
267 	return retval;
268 }
269 
270 static int atmel_ac97c_capture_hw_params(struct snd_pcm_substream *substream,
271 		struct snd_pcm_hw_params *hw_params)
272 {
273 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
274 	int retval;
275 
276 	retval = snd_pcm_lib_malloc_pages(substream,
277 					params_buffer_bytes(hw_params));
278 	if (retval < 0)
279 		return retval;
280 	/* snd_pcm_lib_malloc_pages returns 1 if buffer is changed. */
281 	if (cpu_is_at32ap7000() && retval == 1)
282 		if (test_and_clear_bit(DMA_RX_READY, &chip->flags))
283 			dw_dma_cyclic_free(chip->dma.rx_chan);
284 
285 	/* Set restrictions to params. */
286 	mutex_lock(&opened_mutex);
287 	chip->cur_rate = params_rate(hw_params);
288 	chip->cur_format = params_format(hw_params);
289 	mutex_unlock(&opened_mutex);
290 
291 	return retval;
292 }
293 
294 static int atmel_ac97c_playback_hw_free(struct snd_pcm_substream *substream)
295 {
296 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
297 	if (cpu_is_at32ap7000()) {
298 		if (test_and_clear_bit(DMA_TX_READY, &chip->flags))
299 			dw_dma_cyclic_free(chip->dma.tx_chan);
300 	}
301 	return snd_pcm_lib_free_pages(substream);
302 }
303 
304 static int atmel_ac97c_capture_hw_free(struct snd_pcm_substream *substream)
305 {
306 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
307 	if (cpu_is_at32ap7000()) {
308 		if (test_and_clear_bit(DMA_RX_READY, &chip->flags))
309 			dw_dma_cyclic_free(chip->dma.rx_chan);
310 	}
311 	return snd_pcm_lib_free_pages(substream);
312 }
313 
314 static int atmel_ac97c_playback_prepare(struct snd_pcm_substream *substream)
315 {
316 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
317 	struct snd_pcm_runtime *runtime = substream->runtime;
318 	int block_size = frames_to_bytes(runtime, runtime->period_size);
319 	unsigned long word = ac97c_readl(chip, OCA);
320 	int retval;
321 
322 	chip->playback_period = 0;
323 	word &= ~(AC97C_CH_MASK(PCM_LEFT) | AC97C_CH_MASK(PCM_RIGHT));
324 
325 	/* assign channels to AC97C channel A */
326 	switch (runtime->channels) {
327 	case 1:
328 		word |= AC97C_CH_ASSIGN(PCM_LEFT, A);
329 		break;
330 	case 2:
331 		word |= AC97C_CH_ASSIGN(PCM_LEFT, A)
332 			| AC97C_CH_ASSIGN(PCM_RIGHT, A);
333 		break;
334 	default:
335 		/* TODO: support more than two channels */
336 		return -EINVAL;
337 	}
338 	ac97c_writel(chip, OCA, word);
339 
340 	/* configure sample format and size */
341 	word = ac97c_readl(chip, CAMR);
342 	if (chip->opened <= 1)
343 		word = AC97C_CMR_DMAEN | AC97C_CMR_SIZE_16;
344 	else
345 		word |= AC97C_CMR_DMAEN | AC97C_CMR_SIZE_16;
346 
347 	switch (runtime->format) {
348 	case SNDRV_PCM_FORMAT_S16_LE:
349 		if (cpu_is_at32ap7000())
350 			word |= AC97C_CMR_CEM_LITTLE;
351 		break;
352 	case SNDRV_PCM_FORMAT_S16_BE: /* fall through */
353 		word &= ~(AC97C_CMR_CEM_LITTLE);
354 		break;
355 	default:
356 		word = ac97c_readl(chip, OCA);
357 		word &= ~(AC97C_CH_MASK(PCM_LEFT) | AC97C_CH_MASK(PCM_RIGHT));
358 		ac97c_writel(chip, OCA, word);
359 		return -EINVAL;
360 	}
361 
362 	/* Enable underrun interrupt on channel A */
363 	word |= AC97C_CSR_UNRUN;
364 
365 	ac97c_writel(chip, CAMR, word);
366 
367 	/* Enable channel A event interrupt */
368 	word = ac97c_readl(chip, IMR);
369 	word |= AC97C_SR_CAEVT;
370 	ac97c_writel(chip, IER, word);
371 
372 	/* set variable rate if needed */
373 	if (runtime->rate != 48000) {
374 		word = ac97c_readl(chip, MR);
375 		word |= AC97C_MR_VRA;
376 		ac97c_writel(chip, MR, word);
377 	} else {
378 		word = ac97c_readl(chip, MR);
379 		word &= ~(AC97C_MR_VRA);
380 		ac97c_writel(chip, MR, word);
381 	}
382 
383 	retval = snd_ac97_set_rate(chip->ac97, AC97_PCM_FRONT_DAC_RATE,
384 			runtime->rate);
385 	if (retval)
386 		dev_dbg(&chip->pdev->dev, "could not set rate %d Hz\n",
387 				runtime->rate);
388 
389 	if (cpu_is_at32ap7000()) {
390 		if (!test_bit(DMA_TX_READY, &chip->flags))
391 			retval = atmel_ac97c_prepare_dma(chip, substream,
392 					DMA_MEM_TO_DEV);
393 	} else {
394 		/* Initialize and start the PDC */
395 		writel(runtime->dma_addr, chip->regs + ATMEL_PDC_TPR);
396 		writel(block_size / 2, chip->regs + ATMEL_PDC_TCR);
397 		writel(runtime->dma_addr + block_size,
398 				chip->regs + ATMEL_PDC_TNPR);
399 		writel(block_size / 2, chip->regs + ATMEL_PDC_TNCR);
400 	}
401 
402 	return retval;
403 }
404 
405 static int atmel_ac97c_capture_prepare(struct snd_pcm_substream *substream)
406 {
407 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
408 	struct snd_pcm_runtime *runtime = substream->runtime;
409 	int block_size = frames_to_bytes(runtime, runtime->period_size);
410 	unsigned long word = ac97c_readl(chip, ICA);
411 	int retval;
412 
413 	chip->capture_period = 0;
414 	word &= ~(AC97C_CH_MASK(PCM_LEFT) | AC97C_CH_MASK(PCM_RIGHT));
415 
416 	/* assign channels to AC97C channel A */
417 	switch (runtime->channels) {
418 	case 1:
419 		word |= AC97C_CH_ASSIGN(PCM_LEFT, A);
420 		break;
421 	case 2:
422 		word |= AC97C_CH_ASSIGN(PCM_LEFT, A)
423 			| AC97C_CH_ASSIGN(PCM_RIGHT, A);
424 		break;
425 	default:
426 		/* TODO: support more than two channels */
427 		return -EINVAL;
428 	}
429 	ac97c_writel(chip, ICA, word);
430 
431 	/* configure sample format and size */
432 	word = ac97c_readl(chip, CAMR);
433 	if (chip->opened <= 1)
434 		word = AC97C_CMR_DMAEN | AC97C_CMR_SIZE_16;
435 	else
436 		word |= AC97C_CMR_DMAEN | AC97C_CMR_SIZE_16;
437 
438 	switch (runtime->format) {
439 	case SNDRV_PCM_FORMAT_S16_LE:
440 		if (cpu_is_at32ap7000())
441 			word |= AC97C_CMR_CEM_LITTLE;
442 		break;
443 	case SNDRV_PCM_FORMAT_S16_BE: /* fall through */
444 		word &= ~(AC97C_CMR_CEM_LITTLE);
445 		break;
446 	default:
447 		word = ac97c_readl(chip, ICA);
448 		word &= ~(AC97C_CH_MASK(PCM_LEFT) | AC97C_CH_MASK(PCM_RIGHT));
449 		ac97c_writel(chip, ICA, word);
450 		return -EINVAL;
451 	}
452 
453 	/* Enable overrun interrupt on channel A */
454 	word |= AC97C_CSR_OVRUN;
455 
456 	ac97c_writel(chip, CAMR, word);
457 
458 	/* Enable channel A event interrupt */
459 	word = ac97c_readl(chip, IMR);
460 	word |= AC97C_SR_CAEVT;
461 	ac97c_writel(chip, IER, word);
462 
463 	/* set variable rate if needed */
464 	if (runtime->rate != 48000) {
465 		word = ac97c_readl(chip, MR);
466 		word |= AC97C_MR_VRA;
467 		ac97c_writel(chip, MR, word);
468 	} else {
469 		word = ac97c_readl(chip, MR);
470 		word &= ~(AC97C_MR_VRA);
471 		ac97c_writel(chip, MR, word);
472 	}
473 
474 	retval = snd_ac97_set_rate(chip->ac97, AC97_PCM_LR_ADC_RATE,
475 			runtime->rate);
476 	if (retval)
477 		dev_dbg(&chip->pdev->dev, "could not set rate %d Hz\n",
478 				runtime->rate);
479 
480 	if (cpu_is_at32ap7000()) {
481 		if (!test_bit(DMA_RX_READY, &chip->flags))
482 			retval = atmel_ac97c_prepare_dma(chip, substream,
483 					DMA_DEV_TO_MEM);
484 	} else {
485 		/* Initialize and start the PDC */
486 		writel(runtime->dma_addr, chip->regs + ATMEL_PDC_RPR);
487 		writel(block_size / 2, chip->regs + ATMEL_PDC_RCR);
488 		writel(runtime->dma_addr + block_size,
489 				chip->regs + ATMEL_PDC_RNPR);
490 		writel(block_size / 2, chip->regs + ATMEL_PDC_RNCR);
491 	}
492 
493 	return retval;
494 }
495 
496 static int
497 atmel_ac97c_playback_trigger(struct snd_pcm_substream *substream, int cmd)
498 {
499 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
500 	unsigned long camr, ptcr = 0;
501 	int retval = 0;
502 
503 	camr = ac97c_readl(chip, CAMR);
504 
505 	switch (cmd) {
506 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: /* fall through */
507 	case SNDRV_PCM_TRIGGER_RESUME: /* fall through */
508 	case SNDRV_PCM_TRIGGER_START:
509 		if (cpu_is_at32ap7000()) {
510 			retval = dw_dma_cyclic_start(chip->dma.tx_chan);
511 			if (retval)
512 				goto out;
513 		} else {
514 			ptcr = ATMEL_PDC_TXTEN;
515 		}
516 		camr |= AC97C_CMR_CENA | AC97C_CSR_ENDTX;
517 		break;
518 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH: /* fall through */
519 	case SNDRV_PCM_TRIGGER_SUSPEND: /* fall through */
520 	case SNDRV_PCM_TRIGGER_STOP:
521 		if (cpu_is_at32ap7000())
522 			dw_dma_cyclic_stop(chip->dma.tx_chan);
523 		else
524 			ptcr |= ATMEL_PDC_TXTDIS;
525 		if (chip->opened <= 1)
526 			camr &= ~AC97C_CMR_CENA;
527 		break;
528 	default:
529 		retval = -EINVAL;
530 		goto out;
531 	}
532 
533 	ac97c_writel(chip, CAMR, camr);
534 	if (!cpu_is_at32ap7000())
535 		writel(ptcr, chip->regs + ATMEL_PDC_PTCR);
536 out:
537 	return retval;
538 }
539 
540 static int
541 atmel_ac97c_capture_trigger(struct snd_pcm_substream *substream, int cmd)
542 {
543 	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
544 	unsigned long camr, ptcr = 0;
545 	int retval = 0;
546 
547 	camr = ac97c_readl(chip, CAMR);
548 	ptcr = readl(chip->regs + ATMEL_PDC_PTSR);
549 
550 	switch (cmd) {
551 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: /* fall through */
552 	case SNDRV_PCM_TRIGGER_RESUME: /* fall through */
553 	case SNDRV_PCM_TRIGGER_START:
554 		if (cpu_is_at32ap7000()) {
555 			retval = dw_dma_cyclic_start(chip->dma.rx_chan);
556 			if (retval)
557 				goto out;
558 		} else {
559 			ptcr = ATMEL_PDC_RXTEN;
560 		}
561 		camr |= AC97C_CMR_CENA | AC97C_CSR_ENDRX;
562 		break;
563 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH: /* fall through */
564 	case SNDRV_PCM_TRIGGER_SUSPEND: /* fall through */
565 	case SNDRV_PCM_TRIGGER_STOP:
566 		if (cpu_is_at32ap7000())
567 			dw_dma_cyclic_stop(chip->dma.rx_chan);
568 		else
569 			ptcr |= (ATMEL_PDC_RXTDIS);
570 		if (chip->opened <= 1)
571 			camr &= ~AC97C_CMR_CENA;
572 		break;
573 	default:
574 		retval = -EINVAL;
575 		break;
576 	}
577 
578 	ac97c_writel(chip, CAMR, camr);
579 	if (!cpu_is_at32ap7000())
580 		writel(ptcr, chip->regs + ATMEL_PDC_PTCR);
581 out:
582 	return retval;
583 }
584 
585 static snd_pcm_uframes_t
586 atmel_ac97c_playback_pointer(struct snd_pcm_substream *substream)
587 {
588 	struct atmel_ac97c	*chip = snd_pcm_substream_chip(substream);
589 	struct snd_pcm_runtime	*runtime = substream->runtime;
590 	snd_pcm_uframes_t	frames;
591 	unsigned long		bytes;
592 
593 	if (cpu_is_at32ap7000())
594 		bytes = dw_dma_get_src_addr(chip->dma.tx_chan);
595 	else
596 		bytes = readl(chip->regs + ATMEL_PDC_TPR);
597 	bytes -= runtime->dma_addr;
598 
599 	frames = bytes_to_frames(runtime, bytes);
600 	if (frames >= runtime->buffer_size)
601 		frames -= runtime->buffer_size;
602 	return frames;
603 }
604 
605 static snd_pcm_uframes_t
606 atmel_ac97c_capture_pointer(struct snd_pcm_substream *substream)
607 {
608 	struct atmel_ac97c	*chip = snd_pcm_substream_chip(substream);
609 	struct snd_pcm_runtime	*runtime = substream->runtime;
610 	snd_pcm_uframes_t	frames;
611 	unsigned long		bytes;
612 
613 	if (cpu_is_at32ap7000())
614 		bytes = dw_dma_get_dst_addr(chip->dma.rx_chan);
615 	else
616 		bytes = readl(chip->regs + ATMEL_PDC_RPR);
617 	bytes -= runtime->dma_addr;
618 
619 	frames = bytes_to_frames(runtime, bytes);
620 	if (frames >= runtime->buffer_size)
621 		frames -= runtime->buffer_size;
622 	return frames;
623 }
624 
625 static struct snd_pcm_ops atmel_ac97_playback_ops = {
626 	.open		= atmel_ac97c_playback_open,
627 	.close		= atmel_ac97c_playback_close,
628 	.ioctl		= snd_pcm_lib_ioctl,
629 	.hw_params	= atmel_ac97c_playback_hw_params,
630 	.hw_free	= atmel_ac97c_playback_hw_free,
631 	.prepare	= atmel_ac97c_playback_prepare,
632 	.trigger	= atmel_ac97c_playback_trigger,
633 	.pointer	= atmel_ac97c_playback_pointer,
634 };
635 
636 static struct snd_pcm_ops atmel_ac97_capture_ops = {
637 	.open		= atmel_ac97c_capture_open,
638 	.close		= atmel_ac97c_capture_close,
639 	.ioctl		= snd_pcm_lib_ioctl,
640 	.hw_params	= atmel_ac97c_capture_hw_params,
641 	.hw_free	= atmel_ac97c_capture_hw_free,
642 	.prepare	= atmel_ac97c_capture_prepare,
643 	.trigger	= atmel_ac97c_capture_trigger,
644 	.pointer	= atmel_ac97c_capture_pointer,
645 };
646 
647 static irqreturn_t atmel_ac97c_interrupt(int irq, void *dev)
648 {
649 	struct atmel_ac97c	*chip  = (struct atmel_ac97c *)dev;
650 	irqreturn_t		retval = IRQ_NONE;
651 	u32			sr     = ac97c_readl(chip, SR);
652 	u32			casr   = ac97c_readl(chip, CASR);
653 	u32			cosr   = ac97c_readl(chip, COSR);
654 	u32			camr   = ac97c_readl(chip, CAMR);
655 
656 	if (sr & AC97C_SR_CAEVT) {
657 		struct snd_pcm_runtime *runtime;
658 		int offset, next_period, block_size;
659 		dev_dbg(&chip->pdev->dev, "channel A event%s%s%s%s%s%s\n",
660 				casr & AC97C_CSR_OVRUN   ? " OVRUN"   : "",
661 				casr & AC97C_CSR_RXRDY   ? " RXRDY"   : "",
662 				casr & AC97C_CSR_UNRUN   ? " UNRUN"   : "",
663 				casr & AC97C_CSR_TXEMPTY ? " TXEMPTY" : "",
664 				casr & AC97C_CSR_TXRDY   ? " TXRDY"   : "",
665 				!casr                    ? " NONE"    : "");
666 		if (!cpu_is_at32ap7000()) {
667 			if ((casr & camr) & AC97C_CSR_ENDTX) {
668 				runtime = chip->playback_substream->runtime;
669 				block_size = frames_to_bytes(runtime,
670 						runtime->period_size);
671 				chip->playback_period++;
672 
673 				if (chip->playback_period == runtime->periods)
674 					chip->playback_period = 0;
675 				next_period = chip->playback_period + 1;
676 				if (next_period == runtime->periods)
677 					next_period = 0;
678 
679 				offset = block_size * next_period;
680 
681 				writel(runtime->dma_addr + offset,
682 						chip->regs + ATMEL_PDC_TNPR);
683 				writel(block_size / 2,
684 						chip->regs + ATMEL_PDC_TNCR);
685 
686 				snd_pcm_period_elapsed(
687 						chip->playback_substream);
688 			}
689 			if ((casr & camr) & AC97C_CSR_ENDRX) {
690 				runtime = chip->capture_substream->runtime;
691 				block_size = frames_to_bytes(runtime,
692 						runtime->period_size);
693 				chip->capture_period++;
694 
695 				if (chip->capture_period == runtime->periods)
696 					chip->capture_period = 0;
697 				next_period = chip->capture_period + 1;
698 				if (next_period == runtime->periods)
699 					next_period = 0;
700 
701 				offset = block_size * next_period;
702 
703 				writel(runtime->dma_addr + offset,
704 						chip->regs + ATMEL_PDC_RNPR);
705 				writel(block_size / 2,
706 						chip->regs + ATMEL_PDC_RNCR);
707 				snd_pcm_period_elapsed(chip->capture_substream);
708 			}
709 		}
710 		retval = IRQ_HANDLED;
711 	}
712 
713 	if (sr & AC97C_SR_COEVT) {
714 		dev_info(&chip->pdev->dev, "codec channel event%s%s%s%s%s\n",
715 				cosr & AC97C_CSR_OVRUN   ? " OVRUN"   : "",
716 				cosr & AC97C_CSR_RXRDY   ? " RXRDY"   : "",
717 				cosr & AC97C_CSR_TXEMPTY ? " TXEMPTY" : "",
718 				cosr & AC97C_CSR_TXRDY   ? " TXRDY"   : "",
719 				!cosr                    ? " NONE"    : "");
720 		retval = IRQ_HANDLED;
721 	}
722 
723 	if (retval == IRQ_NONE) {
724 		dev_err(&chip->pdev->dev, "spurious interrupt sr 0x%08x "
725 				"casr 0x%08x cosr 0x%08x\n", sr, casr, cosr);
726 	}
727 
728 	return retval;
729 }
730 
731 static struct ac97_pcm at91_ac97_pcm_defs[] = {
732 	/* Playback */
733 	{
734 		.exclusive = 1,
735 		.r = { {
736 			.slots = ((1 << AC97_SLOT_PCM_LEFT)
737 				  | (1 << AC97_SLOT_PCM_RIGHT)),
738 		} },
739 	},
740 	/* PCM in */
741 	{
742 		.stream = 1,
743 		.exclusive = 1,
744 		.r = { {
745 			.slots = ((1 << AC97_SLOT_PCM_LEFT)
746 					| (1 << AC97_SLOT_PCM_RIGHT)),
747 		} }
748 	},
749 	/* Mic in */
750 	{
751 		.stream = 1,
752 		.exclusive = 1,
753 		.r = { {
754 			.slots = (1<<AC97_SLOT_MIC),
755 		} }
756 	},
757 };
758 
759 static int atmel_ac97c_pcm_new(struct atmel_ac97c *chip)
760 {
761 	struct snd_pcm		*pcm;
762 	struct snd_pcm_hardware	hw = atmel_ac97c_hw;
763 	int			capture, playback, retval, err;
764 
765 	capture = test_bit(DMA_RX_CHAN_PRESENT, &chip->flags);
766 	playback = test_bit(DMA_TX_CHAN_PRESENT, &chip->flags);
767 
768 	if (!cpu_is_at32ap7000()) {
769 		err = snd_ac97_pcm_assign(chip->ac97_bus,
770 				ARRAY_SIZE(at91_ac97_pcm_defs),
771 				at91_ac97_pcm_defs);
772 		if (err)
773 			return err;
774 	}
775 	retval = snd_pcm_new(chip->card, chip->card->shortname,
776 			chip->pdev->id, playback, capture, &pcm);
777 	if (retval)
778 		return retval;
779 
780 	if (capture)
781 		snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE,
782 				&atmel_ac97_capture_ops);
783 	if (playback)
784 		snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK,
785 				&atmel_ac97_playback_ops);
786 
787 	retval = snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
788 			&chip->pdev->dev, hw.periods_min * hw.period_bytes_min,
789 			hw.buffer_bytes_max);
790 	if (retval)
791 		return retval;
792 
793 	pcm->private_data = chip;
794 	pcm->info_flags = 0;
795 	strcpy(pcm->name, chip->card->shortname);
796 	chip->pcm = pcm;
797 
798 	return 0;
799 }
800 
801 static int atmel_ac97c_mixer_new(struct atmel_ac97c *chip)
802 {
803 	struct snd_ac97_template template;
804 	memset(&template, 0, sizeof(template));
805 	template.private_data = chip;
806 	return snd_ac97_mixer(chip->ac97_bus, &template, &chip->ac97);
807 }
808 
809 static void atmel_ac97c_write(struct snd_ac97 *ac97, unsigned short reg,
810 		unsigned short val)
811 {
812 	struct atmel_ac97c *chip = get_chip(ac97);
813 	unsigned long word;
814 	int timeout = 40;
815 
816 	word = (reg & 0x7f) << 16 | val;
817 
818 	do {
819 		if (ac97c_readl(chip, COSR) & AC97C_CSR_TXRDY) {
820 			ac97c_writel(chip, COTHR, word);
821 			return;
822 		}
823 		udelay(1);
824 	} while (--timeout);
825 
826 	dev_dbg(&chip->pdev->dev, "codec write timeout\n");
827 }
828 
829 static unsigned short atmel_ac97c_read(struct snd_ac97 *ac97,
830 		unsigned short reg)
831 {
832 	struct atmel_ac97c *chip = get_chip(ac97);
833 	unsigned long word;
834 	int timeout = 40;
835 	int write = 10;
836 
837 	word = (0x80 | (reg & 0x7f)) << 16;
838 
839 	if ((ac97c_readl(chip, COSR) & AC97C_CSR_RXRDY) != 0)
840 		ac97c_readl(chip, CORHR);
841 
842 retry_write:
843 	timeout = 40;
844 
845 	do {
846 		if ((ac97c_readl(chip, COSR) & AC97C_CSR_TXRDY) != 0) {
847 			ac97c_writel(chip, COTHR, word);
848 			goto read_reg;
849 		}
850 		udelay(10);
851 	} while (--timeout);
852 
853 	if (!--write)
854 		goto timed_out;
855 	goto retry_write;
856 
857 read_reg:
858 	do {
859 		if ((ac97c_readl(chip, COSR) & AC97C_CSR_RXRDY) != 0) {
860 			unsigned short val = ac97c_readl(chip, CORHR);
861 			return val;
862 		}
863 		udelay(10);
864 	} while (--timeout);
865 
866 	if (!--write)
867 		goto timed_out;
868 	goto retry_write;
869 
870 timed_out:
871 	dev_dbg(&chip->pdev->dev, "codec read timeout\n");
872 	return 0xffff;
873 }
874 
875 static bool filter(struct dma_chan *chan, void *slave)
876 {
877 	struct dw_dma_slave *dws = slave;
878 
879 	if (dws->dma_dev == chan->device->dev) {
880 		chan->private = dws;
881 		return true;
882 	} else
883 		return false;
884 }
885 
886 static void atmel_ac97c_reset(struct atmel_ac97c *chip)
887 {
888 	ac97c_writel(chip, MR,   0);
889 	ac97c_writel(chip, MR,   AC97C_MR_ENA);
890 	ac97c_writel(chip, CAMR, 0);
891 	ac97c_writel(chip, COMR, 0);
892 
893 	if (gpio_is_valid(chip->reset_pin)) {
894 		gpio_set_value(chip->reset_pin, 0);
895 		/* AC97 v2.2 specifications says minimum 1 us. */
896 		udelay(2);
897 		gpio_set_value(chip->reset_pin, 1);
898 	} else {
899 		ac97c_writel(chip, MR, AC97C_MR_WRST | AC97C_MR_ENA);
900 		udelay(2);
901 		ac97c_writel(chip, MR, AC97C_MR_ENA);
902 	}
903 }
904 
905 static int atmel_ac97c_probe(struct platform_device *pdev)
906 {
907 	struct snd_card			*card;
908 	struct atmel_ac97c		*chip;
909 	struct resource			*regs;
910 	struct ac97c_platform_data	*pdata;
911 	struct clk			*pclk;
912 	static struct snd_ac97_bus_ops	ops = {
913 		.write	= atmel_ac97c_write,
914 		.read	= atmel_ac97c_read,
915 	};
916 	int				retval;
917 	int				irq;
918 
919 	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
920 	if (!regs) {
921 		dev_dbg(&pdev->dev, "no memory resource\n");
922 		return -ENXIO;
923 	}
924 
925 	pdata = pdev->dev.platform_data;
926 	if (!pdata) {
927 		dev_dbg(&pdev->dev, "no platform data\n");
928 		return -ENXIO;
929 	}
930 
931 	irq = platform_get_irq(pdev, 0);
932 	if (irq < 0) {
933 		dev_dbg(&pdev->dev, "could not get irq\n");
934 		return -ENXIO;
935 	}
936 
937 	if (cpu_is_at32ap7000()) {
938 		pclk = clk_get(&pdev->dev, "pclk");
939 	} else {
940 		pclk = clk_get(&pdev->dev, "ac97_clk");
941 	}
942 
943 	if (IS_ERR(pclk)) {
944 		dev_dbg(&pdev->dev, "no peripheral clock\n");
945 		return PTR_ERR(pclk);
946 	}
947 	clk_enable(pclk);
948 
949 	retval = snd_card_create(SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1,
950 			THIS_MODULE, sizeof(struct atmel_ac97c), &card);
951 	if (retval) {
952 		dev_dbg(&pdev->dev, "could not create sound card device\n");
953 		goto err_snd_card_new;
954 	}
955 
956 	chip = get_chip(card);
957 
958 	retval = request_irq(irq, atmel_ac97c_interrupt, 0, "AC97C", chip);
959 	if (retval) {
960 		dev_dbg(&pdev->dev, "unable to request irq %d\n", irq);
961 		goto err_request_irq;
962 	}
963 	chip->irq = irq;
964 
965 	spin_lock_init(&chip->lock);
966 
967 	strcpy(card->driver, "Atmel AC97C");
968 	strcpy(card->shortname, "Atmel AC97C");
969 	sprintf(card->longname, "Atmel AC97 controller");
970 
971 	chip->card = card;
972 	chip->pclk = pclk;
973 	chip->pdev = pdev;
974 	chip->regs = ioremap(regs->start, resource_size(regs));
975 
976 	if (!chip->regs) {
977 		dev_dbg(&pdev->dev, "could not remap register memory\n");
978 		retval = -ENOMEM;
979 		goto err_ioremap;
980 	}
981 
982 	if (gpio_is_valid(pdata->reset_pin)) {
983 		if (gpio_request(pdata->reset_pin, "reset_pin")) {
984 			dev_dbg(&pdev->dev, "reset pin not available\n");
985 			chip->reset_pin = -ENODEV;
986 		} else {
987 			gpio_direction_output(pdata->reset_pin, 1);
988 			chip->reset_pin = pdata->reset_pin;
989 		}
990 	} else {
991 		chip->reset_pin = -EINVAL;
992 	}
993 
994 	snd_card_set_dev(card, &pdev->dev);
995 
996 	atmel_ac97c_reset(chip);
997 
998 	/* Enable overrun interrupt from codec channel */
999 	ac97c_writel(chip, COMR, AC97C_CSR_OVRUN);
1000 	ac97c_writel(chip, IER, ac97c_readl(chip, IMR) | AC97C_SR_COEVT);
1001 
1002 	retval = snd_ac97_bus(card, 0, &ops, chip, &chip->ac97_bus);
1003 	if (retval) {
1004 		dev_dbg(&pdev->dev, "could not register on ac97 bus\n");
1005 		goto err_ac97_bus;
1006 	}
1007 
1008 	retval = atmel_ac97c_mixer_new(chip);
1009 	if (retval) {
1010 		dev_dbg(&pdev->dev, "could not register ac97 mixer\n");
1011 		goto err_ac97_bus;
1012 	}
1013 
1014 	if (cpu_is_at32ap7000()) {
1015 		if (pdata->rx_dws.dma_dev) {
1016 			dma_cap_mask_t mask;
1017 
1018 			dma_cap_zero(mask);
1019 			dma_cap_set(DMA_SLAVE, mask);
1020 
1021 			chip->dma.rx_chan = dma_request_channel(mask, filter,
1022 								&pdata->rx_dws);
1023 			if (chip->dma.rx_chan) {
1024 				struct dma_slave_config dma_conf = {
1025 					.src_addr = regs->start + AC97C_CARHR +
1026 						2,
1027 					.src_addr_width =
1028 						DMA_SLAVE_BUSWIDTH_2_BYTES,
1029 					.src_maxburst = 1,
1030 					.dst_maxburst = 1,
1031 					.direction = DMA_DEV_TO_MEM,
1032 					.device_fc = false,
1033 				};
1034 
1035 				dmaengine_slave_config(chip->dma.rx_chan,
1036 						&dma_conf);
1037 			}
1038 
1039 			dev_info(&chip->pdev->dev, "using %s for DMA RX\n",
1040 				dev_name(&chip->dma.rx_chan->dev->device));
1041 			set_bit(DMA_RX_CHAN_PRESENT, &chip->flags);
1042 		}
1043 
1044 		if (pdata->tx_dws.dma_dev) {
1045 			dma_cap_mask_t mask;
1046 
1047 			dma_cap_zero(mask);
1048 			dma_cap_set(DMA_SLAVE, mask);
1049 
1050 			chip->dma.tx_chan = dma_request_channel(mask, filter,
1051 								&pdata->tx_dws);
1052 			if (chip->dma.tx_chan) {
1053 				struct dma_slave_config dma_conf = {
1054 					.dst_addr = regs->start + AC97C_CATHR +
1055 						2,
1056 					.dst_addr_width =
1057 						DMA_SLAVE_BUSWIDTH_2_BYTES,
1058 					.src_maxburst = 1,
1059 					.dst_maxburst = 1,
1060 					.direction = DMA_MEM_TO_DEV,
1061 					.device_fc = false,
1062 				};
1063 
1064 				dmaengine_slave_config(chip->dma.tx_chan,
1065 						&dma_conf);
1066 			}
1067 
1068 			dev_info(&chip->pdev->dev, "using %s for DMA TX\n",
1069 				dev_name(&chip->dma.tx_chan->dev->device));
1070 			set_bit(DMA_TX_CHAN_PRESENT, &chip->flags);
1071 		}
1072 
1073 		if (!test_bit(DMA_RX_CHAN_PRESENT, &chip->flags) &&
1074 				!test_bit(DMA_TX_CHAN_PRESENT, &chip->flags)) {
1075 			dev_dbg(&pdev->dev, "DMA not available\n");
1076 			retval = -ENODEV;
1077 			goto err_dma;
1078 		}
1079 	} else {
1080 		/* Just pretend that we have DMA channel(for at91 i is actually
1081 		 * the PDC) */
1082 		set_bit(DMA_RX_CHAN_PRESENT, &chip->flags);
1083 		set_bit(DMA_TX_CHAN_PRESENT, &chip->flags);
1084 	}
1085 
1086 	retval = atmel_ac97c_pcm_new(chip);
1087 	if (retval) {
1088 		dev_dbg(&pdev->dev, "could not register ac97 pcm device\n");
1089 		goto err_dma;
1090 	}
1091 
1092 	retval = snd_card_register(card);
1093 	if (retval) {
1094 		dev_dbg(&pdev->dev, "could not register sound card\n");
1095 		goto err_dma;
1096 	}
1097 
1098 	platform_set_drvdata(pdev, card);
1099 
1100 	dev_info(&pdev->dev, "Atmel AC97 controller at 0x%p, irq = %d\n",
1101 			chip->regs, irq);
1102 
1103 	return 0;
1104 
1105 err_dma:
1106 	if (cpu_is_at32ap7000()) {
1107 		if (test_bit(DMA_RX_CHAN_PRESENT, &chip->flags))
1108 			dma_release_channel(chip->dma.rx_chan);
1109 		if (test_bit(DMA_TX_CHAN_PRESENT, &chip->flags))
1110 			dma_release_channel(chip->dma.tx_chan);
1111 		clear_bit(DMA_RX_CHAN_PRESENT, &chip->flags);
1112 		clear_bit(DMA_TX_CHAN_PRESENT, &chip->flags);
1113 		chip->dma.rx_chan = NULL;
1114 		chip->dma.tx_chan = NULL;
1115 	}
1116 err_ac97_bus:
1117 	snd_card_set_dev(card, NULL);
1118 
1119 	if (gpio_is_valid(chip->reset_pin))
1120 		gpio_free(chip->reset_pin);
1121 
1122 	iounmap(chip->regs);
1123 err_ioremap:
1124 	free_irq(irq, chip);
1125 err_request_irq:
1126 	snd_card_free(card);
1127 err_snd_card_new:
1128 	clk_disable(pclk);
1129 	clk_put(pclk);
1130 	return retval;
1131 }
1132 
1133 #ifdef CONFIG_PM_SLEEP
1134 static int atmel_ac97c_suspend(struct device *pdev)
1135 {
1136 	struct snd_card *card = dev_get_drvdata(pdev);
1137 	struct atmel_ac97c *chip = card->private_data;
1138 
1139 	if (cpu_is_at32ap7000()) {
1140 		if (test_bit(DMA_RX_READY, &chip->flags))
1141 			dw_dma_cyclic_stop(chip->dma.rx_chan);
1142 		if (test_bit(DMA_TX_READY, &chip->flags))
1143 			dw_dma_cyclic_stop(chip->dma.tx_chan);
1144 	}
1145 	clk_disable(chip->pclk);
1146 
1147 	return 0;
1148 }
1149 
1150 static int atmel_ac97c_resume(struct device *pdev)
1151 {
1152 	struct snd_card *card = dev_get_drvdata(pdev);
1153 	struct atmel_ac97c *chip = card->private_data;
1154 
1155 	clk_enable(chip->pclk);
1156 	if (cpu_is_at32ap7000()) {
1157 		if (test_bit(DMA_RX_READY, &chip->flags))
1158 			dw_dma_cyclic_start(chip->dma.rx_chan);
1159 		if (test_bit(DMA_TX_READY, &chip->flags))
1160 			dw_dma_cyclic_start(chip->dma.tx_chan);
1161 	}
1162 	return 0;
1163 }
1164 
1165 static SIMPLE_DEV_PM_OPS(atmel_ac97c_pm, atmel_ac97c_suspend, atmel_ac97c_resume);
1166 #define ATMEL_AC97C_PM_OPS	&atmel_ac97c_pm
1167 #else
1168 #define ATMEL_AC97C_PM_OPS	NULL
1169 #endif
1170 
1171 static int atmel_ac97c_remove(struct platform_device *pdev)
1172 {
1173 	struct snd_card *card = platform_get_drvdata(pdev);
1174 	struct atmel_ac97c *chip = get_chip(card);
1175 
1176 	if (gpio_is_valid(chip->reset_pin))
1177 		gpio_free(chip->reset_pin);
1178 
1179 	ac97c_writel(chip, CAMR, 0);
1180 	ac97c_writel(chip, COMR, 0);
1181 	ac97c_writel(chip, MR,   0);
1182 
1183 	clk_disable(chip->pclk);
1184 	clk_put(chip->pclk);
1185 	iounmap(chip->regs);
1186 	free_irq(chip->irq, chip);
1187 
1188 	if (cpu_is_at32ap7000()) {
1189 		if (test_bit(DMA_RX_CHAN_PRESENT, &chip->flags))
1190 			dma_release_channel(chip->dma.rx_chan);
1191 		if (test_bit(DMA_TX_CHAN_PRESENT, &chip->flags))
1192 			dma_release_channel(chip->dma.tx_chan);
1193 		clear_bit(DMA_RX_CHAN_PRESENT, &chip->flags);
1194 		clear_bit(DMA_TX_CHAN_PRESENT, &chip->flags);
1195 		chip->dma.rx_chan = NULL;
1196 		chip->dma.tx_chan = NULL;
1197 	}
1198 
1199 	snd_card_set_dev(card, NULL);
1200 	snd_card_free(card);
1201 
1202 	return 0;
1203 }
1204 
1205 static struct platform_driver atmel_ac97c_driver = {
1206 	.remove		= atmel_ac97c_remove,
1207 	.driver		= {
1208 		.name	= "atmel_ac97c",
1209 		.owner	= THIS_MODULE,
1210 		.pm	= ATMEL_AC97C_PM_OPS,
1211 	},
1212 };
1213 
1214 static int __init atmel_ac97c_init(void)
1215 {
1216 	return platform_driver_probe(&atmel_ac97c_driver,
1217 			atmel_ac97c_probe);
1218 }
1219 module_init(atmel_ac97c_init);
1220 
1221 static void __exit atmel_ac97c_exit(void)
1222 {
1223 	platform_driver_unregister(&atmel_ac97c_driver);
1224 }
1225 module_exit(atmel_ac97c_exit);
1226 
1227 MODULE_LICENSE("GPL");
1228 MODULE_DESCRIPTION("Driver for Atmel AC97 controller");
1229 MODULE_AUTHOR("Hans-Christian Egtvedt <egtvedt@samfundet.no>");
1230