xref: /openbmc/linux/sound/soc/atmel/atmel_ssc_dai.c (revision 7dd65feb)
1 /*
2  * atmel_ssc_dai.c  --  ALSA SoC ATMEL SSC Audio Layer Platform driver
3  *
4  * Copyright (C) 2005 SAN People
5  * Copyright (C) 2008 Atmel
6  *
7  * Author: Sedji Gaouaou <sedji.gaouaou@atmel.com>
8  *         ATMEL CORP.
9  *
10  * Based on at91-ssc.c by
11  * Frank Mandarino <fmandarino@endrelia.com>
12  * Based on pxa2xx Platform drivers by
13  * Liam Girdwood <lrg@slimlogic.co.uk>
14  *
15  * This program is free software; you can redistribute it and/or modify
16  * it under the terms of the GNU General Public License as published by
17  * the Free Software Foundation; either version 2 of the License, or
18  * (at your option) any later version.
19  *
20  * This program is distributed in the hope that it will be useful,
21  * but WITHOUT ANY WARRANTY; without even the implied warranty of
22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
23  * GNU General Public License for more details.
24  *
25  * You should have received a copy of the GNU General Public License
26  * along with this program; if not, write to the Free Software
27  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
28  */
29 
30 #include <linux/init.h>
31 #include <linux/module.h>
32 #include <linux/interrupt.h>
33 #include <linux/device.h>
34 #include <linux/delay.h>
35 #include <linux/clk.h>
36 #include <linux/atmel_pdc.h>
37 
38 #include <linux/atmel-ssc.h>
39 #include <sound/core.h>
40 #include <sound/pcm.h>
41 #include <sound/pcm_params.h>
42 #include <sound/initval.h>
43 #include <sound/soc.h>
44 
45 #include <mach/hardware.h>
46 
47 #include "atmel-pcm.h"
48 #include "atmel_ssc_dai.h"
49 
50 
51 #if defined(CONFIG_ARCH_AT91SAM9260) || defined(CONFIG_ARCH_AT91SAM9G20)
52 #define NUM_SSC_DEVICES		1
53 #else
54 #define NUM_SSC_DEVICES		3
55 #endif
56 
57 /*
58  * SSC PDC registers required by the PCM DMA engine.
59  */
60 static struct atmel_pdc_regs pdc_tx_reg = {
61 	.xpr		= ATMEL_PDC_TPR,
62 	.xcr		= ATMEL_PDC_TCR,
63 	.xnpr		= ATMEL_PDC_TNPR,
64 	.xncr		= ATMEL_PDC_TNCR,
65 };
66 
67 static struct atmel_pdc_regs pdc_rx_reg = {
68 	.xpr		= ATMEL_PDC_RPR,
69 	.xcr		= ATMEL_PDC_RCR,
70 	.xnpr		= ATMEL_PDC_RNPR,
71 	.xncr		= ATMEL_PDC_RNCR,
72 };
73 
74 /*
75  * SSC & PDC status bits for transmit and receive.
76  */
77 static struct atmel_ssc_mask ssc_tx_mask = {
78 	.ssc_enable	= SSC_BIT(CR_TXEN),
79 	.ssc_disable	= SSC_BIT(CR_TXDIS),
80 	.ssc_endx	= SSC_BIT(SR_ENDTX),
81 	.ssc_endbuf	= SSC_BIT(SR_TXBUFE),
82 	.pdc_enable	= ATMEL_PDC_TXTEN,
83 	.pdc_disable	= ATMEL_PDC_TXTDIS,
84 };
85 
86 static struct atmel_ssc_mask ssc_rx_mask = {
87 	.ssc_enable	= SSC_BIT(CR_RXEN),
88 	.ssc_disable	= SSC_BIT(CR_RXDIS),
89 	.ssc_endx	= SSC_BIT(SR_ENDRX),
90 	.ssc_endbuf	= SSC_BIT(SR_RXBUFF),
91 	.pdc_enable	= ATMEL_PDC_RXTEN,
92 	.pdc_disable	= ATMEL_PDC_RXTDIS,
93 };
94 
95 
96 /*
97  * DMA parameters.
98  */
99 static struct atmel_pcm_dma_params ssc_dma_params[NUM_SSC_DEVICES][2] = {
100 	{{
101 	.name		= "SSC0 PCM out",
102 	.pdc		= &pdc_tx_reg,
103 	.mask		= &ssc_tx_mask,
104 	},
105 	{
106 	.name		= "SSC0 PCM in",
107 	.pdc		= &pdc_rx_reg,
108 	.mask		= &ssc_rx_mask,
109 	} },
110 #if NUM_SSC_DEVICES == 3
111 	{{
112 	.name		= "SSC1 PCM out",
113 	.pdc		= &pdc_tx_reg,
114 	.mask		= &ssc_tx_mask,
115 	},
116 	{
117 	.name		= "SSC1 PCM in",
118 	.pdc		= &pdc_rx_reg,
119 	.mask		= &ssc_rx_mask,
120 	} },
121 	{{
122 	.name		= "SSC2 PCM out",
123 	.pdc		= &pdc_tx_reg,
124 	.mask		= &ssc_tx_mask,
125 	},
126 	{
127 	.name		= "SSC2 PCM in",
128 	.pdc		= &pdc_rx_reg,
129 	.mask		= &ssc_rx_mask,
130 	} },
131 #endif
132 };
133 
134 
135 static struct atmel_ssc_info ssc_info[NUM_SSC_DEVICES] = {
136 	{
137 	.name		= "ssc0",
138 	.lock		= __SPIN_LOCK_UNLOCKED(ssc_info[0].lock),
139 	.dir_mask	= SSC_DIR_MASK_UNUSED,
140 	.initialized	= 0,
141 	},
142 #if NUM_SSC_DEVICES == 3
143 	{
144 	.name		= "ssc1",
145 	.lock		= __SPIN_LOCK_UNLOCKED(ssc_info[1].lock),
146 	.dir_mask	= SSC_DIR_MASK_UNUSED,
147 	.initialized	= 0,
148 	},
149 	{
150 	.name		= "ssc2",
151 	.lock		= __SPIN_LOCK_UNLOCKED(ssc_info[2].lock),
152 	.dir_mask	= SSC_DIR_MASK_UNUSED,
153 	.initialized	= 0,
154 	},
155 #endif
156 };
157 
158 
159 /*
160  * SSC interrupt handler.  Passes PDC interrupts to the DMA
161  * interrupt handler in the PCM driver.
162  */
163 static irqreturn_t atmel_ssc_interrupt(int irq, void *dev_id)
164 {
165 	struct atmel_ssc_info *ssc_p = dev_id;
166 	struct atmel_pcm_dma_params *dma_params;
167 	u32 ssc_sr;
168 	u32 ssc_substream_mask;
169 	int i;
170 
171 	ssc_sr = (unsigned long)ssc_readl(ssc_p->ssc->regs, SR)
172 			& (unsigned long)ssc_readl(ssc_p->ssc->regs, IMR);
173 
174 	/*
175 	 * Loop through the substreams attached to this SSC.  If
176 	 * a DMA-related interrupt occurred on that substream, call
177 	 * the DMA interrupt handler function, if one has been
178 	 * registered in the dma_params structure by the PCM driver.
179 	 */
180 	for (i = 0; i < ARRAY_SIZE(ssc_p->dma_params); i++) {
181 		dma_params = ssc_p->dma_params[i];
182 
183 		if ((dma_params != NULL) &&
184 			(dma_params->dma_intr_handler != NULL)) {
185 			ssc_substream_mask = (dma_params->mask->ssc_endx |
186 					dma_params->mask->ssc_endbuf);
187 			if (ssc_sr & ssc_substream_mask) {
188 				dma_params->dma_intr_handler(ssc_sr,
189 						dma_params->
190 						substream);
191 			}
192 		}
193 	}
194 
195 	return IRQ_HANDLED;
196 }
197 
198 
199 /*-------------------------------------------------------------------------*\
200  * DAI functions
201 \*-------------------------------------------------------------------------*/
202 /*
203  * Startup.  Only that one substream allowed in each direction.
204  */
205 static int atmel_ssc_startup(struct snd_pcm_substream *substream,
206 			     struct snd_soc_dai *dai)
207 {
208 	struct snd_soc_pcm_runtime *rtd = snd_pcm_substream_chip(substream);
209 	struct atmel_ssc_info *ssc_p = &ssc_info[rtd->dai->cpu_dai->id];
210 	int dir_mask;
211 
212 	pr_debug("atmel_ssc_startup: SSC_SR=0x%u\n",
213 		ssc_readl(ssc_p->ssc->regs, SR));
214 
215 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
216 		dir_mask = SSC_DIR_MASK_PLAYBACK;
217 	else
218 		dir_mask = SSC_DIR_MASK_CAPTURE;
219 
220 	spin_lock_irq(&ssc_p->lock);
221 	if (ssc_p->dir_mask & dir_mask) {
222 		spin_unlock_irq(&ssc_p->lock);
223 		return -EBUSY;
224 	}
225 	ssc_p->dir_mask |= dir_mask;
226 	spin_unlock_irq(&ssc_p->lock);
227 
228 	return 0;
229 }
230 
231 /*
232  * Shutdown.  Clear DMA parameters and shutdown the SSC if there
233  * are no other substreams open.
234  */
235 static void atmel_ssc_shutdown(struct snd_pcm_substream *substream,
236 			       struct snd_soc_dai *dai)
237 {
238 	struct snd_soc_pcm_runtime *rtd = snd_pcm_substream_chip(substream);
239 	struct atmel_ssc_info *ssc_p = &ssc_info[rtd->dai->cpu_dai->id];
240 	struct atmel_pcm_dma_params *dma_params;
241 	int dir, dir_mask;
242 
243 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
244 		dir = 0;
245 	else
246 		dir = 1;
247 
248 	dma_params = ssc_p->dma_params[dir];
249 
250 	if (dma_params != NULL) {
251 		ssc_writel(ssc_p->ssc->regs, CR, dma_params->mask->ssc_disable);
252 		pr_debug("atmel_ssc_shutdown: %s disabled SSC_SR=0x%08x\n",
253 			(dir ? "receive" : "transmit"),
254 			ssc_readl(ssc_p->ssc->regs, SR));
255 
256 		dma_params->ssc = NULL;
257 		dma_params->substream = NULL;
258 		ssc_p->dma_params[dir] = NULL;
259 	}
260 
261 	dir_mask = 1 << dir;
262 
263 	spin_lock_irq(&ssc_p->lock);
264 	ssc_p->dir_mask &= ~dir_mask;
265 	if (!ssc_p->dir_mask) {
266 		if (ssc_p->initialized) {
267 			/* Shutdown the SSC clock. */
268 			pr_debug("atmel_ssc_dau: Stopping clock\n");
269 			clk_disable(ssc_p->ssc->clk);
270 
271 			free_irq(ssc_p->ssc->irq, ssc_p);
272 			ssc_p->initialized = 0;
273 		}
274 
275 		/* Reset the SSC */
276 		ssc_writel(ssc_p->ssc->regs, CR, SSC_BIT(CR_SWRST));
277 		/* Clear the SSC dividers */
278 		ssc_p->cmr_div = ssc_p->tcmr_period = ssc_p->rcmr_period = 0;
279 	}
280 	spin_unlock_irq(&ssc_p->lock);
281 }
282 
283 
284 /*
285  * Record the DAI format for use in hw_params().
286  */
287 static int atmel_ssc_set_dai_fmt(struct snd_soc_dai *cpu_dai,
288 		unsigned int fmt)
289 {
290 	struct atmel_ssc_info *ssc_p = &ssc_info[cpu_dai->id];
291 
292 	ssc_p->daifmt = fmt;
293 	return 0;
294 }
295 
296 /*
297  * Record SSC clock dividers for use in hw_params().
298  */
299 static int atmel_ssc_set_dai_clkdiv(struct snd_soc_dai *cpu_dai,
300 	int div_id, int div)
301 {
302 	struct atmel_ssc_info *ssc_p = &ssc_info[cpu_dai->id];
303 
304 	switch (div_id) {
305 	case ATMEL_SSC_CMR_DIV:
306 		/*
307 		 * The same master clock divider is used for both
308 		 * transmit and receive, so if a value has already
309 		 * been set, it must match this value.
310 		 */
311 		if (ssc_p->cmr_div == 0)
312 			ssc_p->cmr_div = div;
313 		else
314 			if (div != ssc_p->cmr_div)
315 				return -EBUSY;
316 		break;
317 
318 	case ATMEL_SSC_TCMR_PERIOD:
319 		ssc_p->tcmr_period = div;
320 		break;
321 
322 	case ATMEL_SSC_RCMR_PERIOD:
323 		ssc_p->rcmr_period = div;
324 		break;
325 
326 	default:
327 		return -EINVAL;
328 	}
329 
330 	return 0;
331 }
332 
333 /*
334  * Configure the SSC.
335  */
336 static int atmel_ssc_hw_params(struct snd_pcm_substream *substream,
337 	struct snd_pcm_hw_params *params,
338 	struct snd_soc_dai *dai)
339 {
340 	struct snd_soc_pcm_runtime *rtd = snd_pcm_substream_chip(substream);
341 	int id = rtd->dai->cpu_dai->id;
342 	struct atmel_ssc_info *ssc_p = &ssc_info[id];
343 	struct atmel_pcm_dma_params *dma_params;
344 	int dir, channels, bits;
345 	u32 tfmr, rfmr, tcmr, rcmr;
346 	int start_event;
347 	int ret;
348 
349 	/*
350 	 * Currently, there is only one set of dma params for
351 	 * each direction.  If more are added, this code will
352 	 * have to be changed to select the proper set.
353 	 */
354 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
355 		dir = 0;
356 	else
357 		dir = 1;
358 
359 	dma_params = &ssc_dma_params[id][dir];
360 	dma_params->ssc = ssc_p->ssc;
361 	dma_params->substream = substream;
362 
363 	ssc_p->dma_params[dir] = dma_params;
364 
365 	/*
366 	 * The cpu_dai->dma_data field is only used to communicate the
367 	 * appropriate DMA parameters to the pcm driver hw_params()
368 	 * function.  It should not be used for other purposes
369 	 * as it is common to all substreams.
370 	 */
371 	rtd->dai->cpu_dai->dma_data = dma_params;
372 
373 	channels = params_channels(params);
374 
375 	/*
376 	 * Determine sample size in bits and the PDC increment.
377 	 */
378 	switch (params_format(params)) {
379 	case SNDRV_PCM_FORMAT_S8:
380 		bits = 8;
381 		dma_params->pdc_xfer_size = 1;
382 		break;
383 	case SNDRV_PCM_FORMAT_S16_LE:
384 		bits = 16;
385 		dma_params->pdc_xfer_size = 2;
386 		break;
387 	case SNDRV_PCM_FORMAT_S24_LE:
388 		bits = 24;
389 		dma_params->pdc_xfer_size = 4;
390 		break;
391 	case SNDRV_PCM_FORMAT_S32_LE:
392 		bits = 32;
393 		dma_params->pdc_xfer_size = 4;
394 		break;
395 	default:
396 		printk(KERN_WARNING "atmel_ssc_dai: unsupported PCM format");
397 		return -EINVAL;
398 	}
399 
400 	/*
401 	 * The SSC only supports up to 16-bit samples in I2S format, due
402 	 * to the size of the Frame Mode Register FSLEN field.
403 	 */
404 	if ((ssc_p->daifmt & SND_SOC_DAIFMT_FORMAT_MASK) == SND_SOC_DAIFMT_I2S
405 		&& bits > 16) {
406 		printk(KERN_WARNING
407 				"atmel_ssc_dai: sample size %d"
408 				"is too large for I2S\n", bits);
409 		return -EINVAL;
410 	}
411 
412 	/*
413 	 * Compute SSC register settings.
414 	 */
415 	switch (ssc_p->daifmt
416 		& (SND_SOC_DAIFMT_FORMAT_MASK | SND_SOC_DAIFMT_MASTER_MASK)) {
417 
418 	case SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_CBS_CFS:
419 		/*
420 		 * I2S format, SSC provides BCLK and LRC clocks.
421 		 *
422 		 * The SSC transmit and receive clocks are generated
423 		 * from the MCK divider, and the BCLK signal
424 		 * is output on the SSC TK line.
425 		 */
426 		rcmr =	  SSC_BF(RCMR_PERIOD, ssc_p->rcmr_period)
427 			| SSC_BF(RCMR_STTDLY, START_DELAY)
428 			| SSC_BF(RCMR_START, SSC_START_FALLING_RF)
429 			| SSC_BF(RCMR_CKI, SSC_CKI_RISING)
430 			| SSC_BF(RCMR_CKO, SSC_CKO_NONE)
431 			| SSC_BF(RCMR_CKS, SSC_CKS_DIV);
432 
433 		rfmr =	  SSC_BF(RFMR_FSEDGE, SSC_FSEDGE_POSITIVE)
434 			| SSC_BF(RFMR_FSOS, SSC_FSOS_NEGATIVE)
435 			| SSC_BF(RFMR_FSLEN, (bits - 1))
436 			| SSC_BF(RFMR_DATNB, (channels - 1))
437 			| SSC_BIT(RFMR_MSBF)
438 			| SSC_BF(RFMR_LOOP, 0)
439 			| SSC_BF(RFMR_DATLEN, (bits - 1));
440 
441 		tcmr =	  SSC_BF(TCMR_PERIOD, ssc_p->tcmr_period)
442 			| SSC_BF(TCMR_STTDLY, START_DELAY)
443 			| SSC_BF(TCMR_START, SSC_START_FALLING_RF)
444 			| SSC_BF(TCMR_CKI, SSC_CKI_FALLING)
445 			| SSC_BF(TCMR_CKO, SSC_CKO_CONTINUOUS)
446 			| SSC_BF(TCMR_CKS, SSC_CKS_DIV);
447 
448 		tfmr =	  SSC_BF(TFMR_FSEDGE, SSC_FSEDGE_POSITIVE)
449 			| SSC_BF(TFMR_FSDEN, 0)
450 			| SSC_BF(TFMR_FSOS, SSC_FSOS_NEGATIVE)
451 			| SSC_BF(TFMR_FSLEN, (bits - 1))
452 			| SSC_BF(TFMR_DATNB, (channels - 1))
453 			| SSC_BIT(TFMR_MSBF)
454 			| SSC_BF(TFMR_DATDEF, 0)
455 			| SSC_BF(TFMR_DATLEN, (bits - 1));
456 		break;
457 
458 	case SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_CBM_CFM:
459 		/*
460 		 * I2S format, CODEC supplies BCLK and LRC clocks.
461 		 *
462 		 * The SSC transmit clock is obtained from the BCLK signal on
463 		 * on the TK line, and the SSC receive clock is
464 		 * generated from the transmit clock.
465 		 *
466 		 *  For single channel data, one sample is transferred
467 		 * on the falling edge of the LRC clock.
468 		 * For two channel data, one sample is
469 		 * transferred on both edges of the LRC clock.
470 		 */
471 		start_event = ((channels == 1)
472 				? SSC_START_FALLING_RF
473 				: SSC_START_EDGE_RF);
474 
475 		rcmr =	  SSC_BF(RCMR_PERIOD, 0)
476 			| SSC_BF(RCMR_STTDLY, START_DELAY)
477 			| SSC_BF(RCMR_START, start_event)
478 			| SSC_BF(RCMR_CKI, SSC_CKI_RISING)
479 			| SSC_BF(RCMR_CKO, SSC_CKO_NONE)
480 			| SSC_BF(RCMR_CKS, SSC_CKS_CLOCK);
481 
482 		rfmr =	  SSC_BF(RFMR_FSEDGE, SSC_FSEDGE_POSITIVE)
483 			| SSC_BF(RFMR_FSOS, SSC_FSOS_NONE)
484 			| SSC_BF(RFMR_FSLEN, 0)
485 			| SSC_BF(RFMR_DATNB, 0)
486 			| SSC_BIT(RFMR_MSBF)
487 			| SSC_BF(RFMR_LOOP, 0)
488 			| SSC_BF(RFMR_DATLEN, (bits - 1));
489 
490 		tcmr =	  SSC_BF(TCMR_PERIOD, 0)
491 			| SSC_BF(TCMR_STTDLY, START_DELAY)
492 			| SSC_BF(TCMR_START, start_event)
493 			| SSC_BF(TCMR_CKI, SSC_CKI_FALLING)
494 			| SSC_BF(TCMR_CKO, SSC_CKO_NONE)
495 			| SSC_BF(TCMR_CKS, SSC_CKS_PIN);
496 
497 		tfmr =	  SSC_BF(TFMR_FSEDGE, SSC_FSEDGE_POSITIVE)
498 			| SSC_BF(TFMR_FSDEN, 0)
499 			| SSC_BF(TFMR_FSOS, SSC_FSOS_NONE)
500 			| SSC_BF(TFMR_FSLEN, 0)
501 			| SSC_BF(TFMR_DATNB, 0)
502 			| SSC_BIT(TFMR_MSBF)
503 			| SSC_BF(TFMR_DATDEF, 0)
504 			| SSC_BF(TFMR_DATLEN, (bits - 1));
505 		break;
506 
507 	case SND_SOC_DAIFMT_DSP_A | SND_SOC_DAIFMT_CBS_CFS:
508 		/*
509 		 * DSP/PCM Mode A format, SSC provides BCLK and LRC clocks.
510 		 *
511 		 * The SSC transmit and receive clocks are generated from the
512 		 * MCK divider, and the BCLK signal is output
513 		 * on the SSC TK line.
514 		 */
515 		rcmr =	  SSC_BF(RCMR_PERIOD, ssc_p->rcmr_period)
516 			| SSC_BF(RCMR_STTDLY, 1)
517 			| SSC_BF(RCMR_START, SSC_START_RISING_RF)
518 			| SSC_BF(RCMR_CKI, SSC_CKI_RISING)
519 			| SSC_BF(RCMR_CKO, SSC_CKO_NONE)
520 			| SSC_BF(RCMR_CKS, SSC_CKS_DIV);
521 
522 		rfmr =	  SSC_BF(RFMR_FSEDGE, SSC_FSEDGE_POSITIVE)
523 			| SSC_BF(RFMR_FSOS, SSC_FSOS_POSITIVE)
524 			| SSC_BF(RFMR_FSLEN, 0)
525 			| SSC_BF(RFMR_DATNB, (channels - 1))
526 			| SSC_BIT(RFMR_MSBF)
527 			| SSC_BF(RFMR_LOOP, 0)
528 			| SSC_BF(RFMR_DATLEN, (bits - 1));
529 
530 		tcmr =	  SSC_BF(TCMR_PERIOD, ssc_p->tcmr_period)
531 			| SSC_BF(TCMR_STTDLY, 1)
532 			| SSC_BF(TCMR_START, SSC_START_RISING_RF)
533 			| SSC_BF(TCMR_CKI, SSC_CKI_RISING)
534 			| SSC_BF(TCMR_CKO, SSC_CKO_CONTINUOUS)
535 			| SSC_BF(TCMR_CKS, SSC_CKS_DIV);
536 
537 		tfmr =	  SSC_BF(TFMR_FSEDGE, SSC_FSEDGE_POSITIVE)
538 			| SSC_BF(TFMR_FSDEN, 0)
539 			| SSC_BF(TFMR_FSOS, SSC_FSOS_POSITIVE)
540 			| SSC_BF(TFMR_FSLEN, 0)
541 			| SSC_BF(TFMR_DATNB, (channels - 1))
542 			| SSC_BIT(TFMR_MSBF)
543 			| SSC_BF(TFMR_DATDEF, 0)
544 			| SSC_BF(TFMR_DATLEN, (bits - 1));
545 		break;
546 
547 	case SND_SOC_DAIFMT_DSP_A | SND_SOC_DAIFMT_CBM_CFM:
548 	default:
549 		printk(KERN_WARNING "atmel_ssc_dai: unsupported DAI format 0x%x\n",
550 			ssc_p->daifmt);
551 		return -EINVAL;
552 		break;
553 	}
554 	pr_debug("atmel_ssc_hw_params: "
555 			"RCMR=%08x RFMR=%08x TCMR=%08x TFMR=%08x\n",
556 			rcmr, rfmr, tcmr, tfmr);
557 
558 	if (!ssc_p->initialized) {
559 
560 		/* Enable PMC peripheral clock for this SSC */
561 		pr_debug("atmel_ssc_dai: Starting clock\n");
562 		clk_enable(ssc_p->ssc->clk);
563 
564 		/* Reset the SSC and its PDC registers */
565 		ssc_writel(ssc_p->ssc->regs, CR, SSC_BIT(CR_SWRST));
566 
567 		ssc_writel(ssc_p->ssc->regs, PDC_RPR, 0);
568 		ssc_writel(ssc_p->ssc->regs, PDC_RCR, 0);
569 		ssc_writel(ssc_p->ssc->regs, PDC_RNPR, 0);
570 		ssc_writel(ssc_p->ssc->regs, PDC_RNCR, 0);
571 
572 		ssc_writel(ssc_p->ssc->regs, PDC_TPR, 0);
573 		ssc_writel(ssc_p->ssc->regs, PDC_TCR, 0);
574 		ssc_writel(ssc_p->ssc->regs, PDC_TNPR, 0);
575 		ssc_writel(ssc_p->ssc->regs, PDC_TNCR, 0);
576 
577 		ret = request_irq(ssc_p->ssc->irq, atmel_ssc_interrupt, 0,
578 				ssc_p->name, ssc_p);
579 		if (ret < 0) {
580 			printk(KERN_WARNING
581 					"atmel_ssc_dai: request_irq failure\n");
582 			pr_debug("Atmel_ssc_dai: Stoping clock\n");
583 			clk_disable(ssc_p->ssc->clk);
584 			return ret;
585 		}
586 
587 		ssc_p->initialized = 1;
588 	}
589 
590 	/* set SSC clock mode register */
591 	ssc_writel(ssc_p->ssc->regs, CMR, ssc_p->cmr_div);
592 
593 	/* set receive clock mode and format */
594 	ssc_writel(ssc_p->ssc->regs, RCMR, rcmr);
595 	ssc_writel(ssc_p->ssc->regs, RFMR, rfmr);
596 
597 	/* set transmit clock mode and format */
598 	ssc_writel(ssc_p->ssc->regs, TCMR, tcmr);
599 	ssc_writel(ssc_p->ssc->regs, TFMR, tfmr);
600 
601 	pr_debug("atmel_ssc_dai,hw_params: SSC initialized\n");
602 	return 0;
603 }
604 
605 
606 static int atmel_ssc_prepare(struct snd_pcm_substream *substream,
607 			     struct snd_soc_dai *dai)
608 {
609 	struct snd_soc_pcm_runtime *rtd = snd_pcm_substream_chip(substream);
610 	struct atmel_ssc_info *ssc_p = &ssc_info[rtd->dai->cpu_dai->id];
611 	struct atmel_pcm_dma_params *dma_params;
612 	int dir;
613 
614 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
615 		dir = 0;
616 	else
617 		dir = 1;
618 
619 	dma_params = ssc_p->dma_params[dir];
620 
621 	ssc_writel(ssc_p->ssc->regs, CR, dma_params->mask->ssc_enable);
622 
623 	pr_debug("%s enabled SSC_SR=0x%08x\n",
624 			dir ? "receive" : "transmit",
625 			ssc_readl(ssc_p->ssc->regs, SR));
626 	return 0;
627 }
628 
629 
630 #ifdef CONFIG_PM
631 static int atmel_ssc_suspend(struct snd_soc_dai *cpu_dai)
632 {
633 	struct atmel_ssc_info *ssc_p;
634 
635 	if (!cpu_dai->active)
636 		return 0;
637 
638 	ssc_p = &ssc_info[cpu_dai->id];
639 
640 	/* Save the status register before disabling transmit and receive */
641 	ssc_p->ssc_state.ssc_sr = ssc_readl(ssc_p->ssc->regs, SR);
642 	ssc_writel(ssc_p->ssc->regs, CR, SSC_BIT(CR_TXDIS) | SSC_BIT(CR_RXDIS));
643 
644 	/* Save the current interrupt mask, then disable unmasked interrupts */
645 	ssc_p->ssc_state.ssc_imr = ssc_readl(ssc_p->ssc->regs, IMR);
646 	ssc_writel(ssc_p->ssc->regs, IDR, ssc_p->ssc_state.ssc_imr);
647 
648 	ssc_p->ssc_state.ssc_cmr = ssc_readl(ssc_p->ssc->regs, CMR);
649 	ssc_p->ssc_state.ssc_rcmr = ssc_readl(ssc_p->ssc->regs, RCMR);
650 	ssc_p->ssc_state.ssc_rfmr = ssc_readl(ssc_p->ssc->regs, RFMR);
651 	ssc_p->ssc_state.ssc_tcmr = ssc_readl(ssc_p->ssc->regs, TCMR);
652 	ssc_p->ssc_state.ssc_tfmr = ssc_readl(ssc_p->ssc->regs, TFMR);
653 
654 	return 0;
655 }
656 
657 
658 
659 static int atmel_ssc_resume(struct snd_soc_dai *cpu_dai)
660 {
661 	struct atmel_ssc_info *ssc_p;
662 	u32 cr;
663 
664 	if (!cpu_dai->active)
665 		return 0;
666 
667 	ssc_p = &ssc_info[cpu_dai->id];
668 
669 	/* restore SSC register settings */
670 	ssc_writel(ssc_p->ssc->regs, TFMR, ssc_p->ssc_state.ssc_tfmr);
671 	ssc_writel(ssc_p->ssc->regs, TCMR, ssc_p->ssc_state.ssc_tcmr);
672 	ssc_writel(ssc_p->ssc->regs, RFMR, ssc_p->ssc_state.ssc_rfmr);
673 	ssc_writel(ssc_p->ssc->regs, RCMR, ssc_p->ssc_state.ssc_rcmr);
674 	ssc_writel(ssc_p->ssc->regs, CMR, ssc_p->ssc_state.ssc_cmr);
675 
676 	/* re-enable interrupts */
677 	ssc_writel(ssc_p->ssc->regs, IER, ssc_p->ssc_state.ssc_imr);
678 
679 	/* Re-enable recieve and transmit as appropriate */
680 	cr = 0;
681 	cr |=
682 	    (ssc_p->ssc_state.ssc_sr & SSC_BIT(SR_RXEN)) ? SSC_BIT(CR_RXEN) : 0;
683 	cr |=
684 	    (ssc_p->ssc_state.ssc_sr & SSC_BIT(SR_TXEN)) ? SSC_BIT(CR_TXEN) : 0;
685 	ssc_writel(ssc_p->ssc->regs, CR, cr);
686 
687 	return 0;
688 }
689 #else /* CONFIG_PM */
690 #  define atmel_ssc_suspend	NULL
691 #  define atmel_ssc_resume	NULL
692 #endif /* CONFIG_PM */
693 
694 
695 #define ATMEL_SSC_RATES (SNDRV_PCM_RATE_8000_96000)
696 
697 #define ATMEL_SSC_FORMATS (SNDRV_PCM_FMTBIT_S8     | SNDRV_PCM_FMTBIT_S16_LE |\
698 			  SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S32_LE)
699 
700 static struct snd_soc_dai_ops atmel_ssc_dai_ops = {
701 	.startup	= atmel_ssc_startup,
702 	.shutdown	= atmel_ssc_shutdown,
703 	.prepare	= atmel_ssc_prepare,
704 	.hw_params	= atmel_ssc_hw_params,
705 	.set_fmt	= atmel_ssc_set_dai_fmt,
706 	.set_clkdiv	= atmel_ssc_set_dai_clkdiv,
707 };
708 
709 struct snd_soc_dai atmel_ssc_dai[NUM_SSC_DEVICES] = {
710 	{	.name = "atmel-ssc0",
711 		.id = 0,
712 		.suspend = atmel_ssc_suspend,
713 		.resume = atmel_ssc_resume,
714 		.playback = {
715 			.channels_min = 1,
716 			.channels_max = 2,
717 			.rates = ATMEL_SSC_RATES,
718 			.formats = ATMEL_SSC_FORMATS,},
719 		.capture = {
720 			.channels_min = 1,
721 			.channels_max = 2,
722 			.rates = ATMEL_SSC_RATES,
723 			.formats = ATMEL_SSC_FORMATS,},
724 		.ops = &atmel_ssc_dai_ops,
725 		.private_data = &ssc_info[0],
726 	},
727 #if NUM_SSC_DEVICES == 3
728 	{	.name = "atmel-ssc1",
729 		.id = 1,
730 		.suspend = atmel_ssc_suspend,
731 		.resume = atmel_ssc_resume,
732 		.playback = {
733 			.channels_min = 1,
734 			.channels_max = 2,
735 			.rates = ATMEL_SSC_RATES,
736 			.formats = ATMEL_SSC_FORMATS,},
737 		.capture = {
738 			.channels_min = 1,
739 			.channels_max = 2,
740 			.rates = ATMEL_SSC_RATES,
741 			.formats = ATMEL_SSC_FORMATS,},
742 		.ops = &atmel_ssc_dai_ops,
743 		.private_data = &ssc_info[1],
744 	},
745 	{	.name = "atmel-ssc2",
746 		.id = 2,
747 		.suspend = atmel_ssc_suspend,
748 		.resume = atmel_ssc_resume,
749 		.playback = {
750 			.channels_min = 1,
751 			.channels_max = 2,
752 			.rates = ATMEL_SSC_RATES,
753 			.formats = ATMEL_SSC_FORMATS,},
754 		.capture = {
755 			.channels_min = 1,
756 			.channels_max = 2,
757 			.rates = ATMEL_SSC_RATES,
758 			.formats = ATMEL_SSC_FORMATS,},
759 		.ops = &atmel_ssc_dai_ops,
760 		.private_data = &ssc_info[2],
761 	},
762 #endif
763 };
764 EXPORT_SYMBOL_GPL(atmel_ssc_dai);
765 
766 static int __init atmel_ssc_modinit(void)
767 {
768 	return snd_soc_register_dais(atmel_ssc_dai, ARRAY_SIZE(atmel_ssc_dai));
769 }
770 module_init(atmel_ssc_modinit);
771 
772 static void __exit atmel_ssc_modexit(void)
773 {
774 	snd_soc_unregister_dais(atmel_ssc_dai, ARRAY_SIZE(atmel_ssc_dai));
775 }
776 module_exit(atmel_ssc_modexit);
777 
778 /* Module information */
779 MODULE_AUTHOR("Sedji Gaouaou, sedji.gaouaou@atmel.com, www.atmel.com");
780 MODULE_DESCRIPTION("ATMEL SSC ASoC Interface");
781 MODULE_LICENSE("GPL");
782