xref: /openbmc/linux/sound/soc/atmel/atmel_ssc_dai.c (revision 089a49b6)
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 "atmel-pcm.h"
46 #include "atmel_ssc_dai.h"
47 
48 
49 #define NUM_SSC_DEVICES		3
50 
51 /*
52  * SSC PDC registers required by the PCM DMA engine.
53  */
54 static struct atmel_pdc_regs pdc_tx_reg = {
55 	.xpr		= ATMEL_PDC_TPR,
56 	.xcr		= ATMEL_PDC_TCR,
57 	.xnpr		= ATMEL_PDC_TNPR,
58 	.xncr		= ATMEL_PDC_TNCR,
59 };
60 
61 static struct atmel_pdc_regs pdc_rx_reg = {
62 	.xpr		= ATMEL_PDC_RPR,
63 	.xcr		= ATMEL_PDC_RCR,
64 	.xnpr		= ATMEL_PDC_RNPR,
65 	.xncr		= ATMEL_PDC_RNCR,
66 };
67 
68 /*
69  * SSC & PDC status bits for transmit and receive.
70  */
71 static struct atmel_ssc_mask ssc_tx_mask = {
72 	.ssc_enable	= SSC_BIT(CR_TXEN),
73 	.ssc_disable	= SSC_BIT(CR_TXDIS),
74 	.ssc_endx	= SSC_BIT(SR_ENDTX),
75 	.ssc_endbuf	= SSC_BIT(SR_TXBUFE),
76 	.ssc_error	= SSC_BIT(SR_OVRUN),
77 	.pdc_enable	= ATMEL_PDC_TXTEN,
78 	.pdc_disable	= ATMEL_PDC_TXTDIS,
79 };
80 
81 static struct atmel_ssc_mask ssc_rx_mask = {
82 	.ssc_enable	= SSC_BIT(CR_RXEN),
83 	.ssc_disable	= SSC_BIT(CR_RXDIS),
84 	.ssc_endx	= SSC_BIT(SR_ENDRX),
85 	.ssc_endbuf	= SSC_BIT(SR_RXBUFF),
86 	.ssc_error	= SSC_BIT(SR_OVRUN),
87 	.pdc_enable	= ATMEL_PDC_RXTEN,
88 	.pdc_disable	= ATMEL_PDC_RXTDIS,
89 };
90 
91 
92 /*
93  * DMA parameters.
94  */
95 static struct atmel_pcm_dma_params ssc_dma_params[NUM_SSC_DEVICES][2] = {
96 	{{
97 	.name		= "SSC0 PCM out",
98 	.pdc		= &pdc_tx_reg,
99 	.mask		= &ssc_tx_mask,
100 	},
101 	{
102 	.name		= "SSC0 PCM in",
103 	.pdc		= &pdc_rx_reg,
104 	.mask		= &ssc_rx_mask,
105 	} },
106 	{{
107 	.name		= "SSC1 PCM out",
108 	.pdc		= &pdc_tx_reg,
109 	.mask		= &ssc_tx_mask,
110 	},
111 	{
112 	.name		= "SSC1 PCM in",
113 	.pdc		= &pdc_rx_reg,
114 	.mask		= &ssc_rx_mask,
115 	} },
116 	{{
117 	.name		= "SSC2 PCM out",
118 	.pdc		= &pdc_tx_reg,
119 	.mask		= &ssc_tx_mask,
120 	},
121 	{
122 	.name		= "SSC2 PCM in",
123 	.pdc		= &pdc_rx_reg,
124 	.mask		= &ssc_rx_mask,
125 	} },
126 };
127 
128 
129 static struct atmel_ssc_info ssc_info[NUM_SSC_DEVICES] = {
130 	{
131 	.name		= "ssc0",
132 	.lock		= __SPIN_LOCK_UNLOCKED(ssc_info[0].lock),
133 	.dir_mask	= SSC_DIR_MASK_UNUSED,
134 	.initialized	= 0,
135 	},
136 	{
137 	.name		= "ssc1",
138 	.lock		= __SPIN_LOCK_UNLOCKED(ssc_info[1].lock),
139 	.dir_mask	= SSC_DIR_MASK_UNUSED,
140 	.initialized	= 0,
141 	},
142 	{
143 	.name		= "ssc2",
144 	.lock		= __SPIN_LOCK_UNLOCKED(ssc_info[2].lock),
145 	.dir_mask	= SSC_DIR_MASK_UNUSED,
146 	.initialized	= 0,
147 	},
148 };
149 
150 
151 /*
152  * SSC interrupt handler.  Passes PDC interrupts to the DMA
153  * interrupt handler in the PCM driver.
154  */
155 static irqreturn_t atmel_ssc_interrupt(int irq, void *dev_id)
156 {
157 	struct atmel_ssc_info *ssc_p = dev_id;
158 	struct atmel_pcm_dma_params *dma_params;
159 	u32 ssc_sr;
160 	u32 ssc_substream_mask;
161 	int i;
162 
163 	ssc_sr = (unsigned long)ssc_readl(ssc_p->ssc->regs, SR)
164 			& (unsigned long)ssc_readl(ssc_p->ssc->regs, IMR);
165 
166 	/*
167 	 * Loop through the substreams attached to this SSC.  If
168 	 * a DMA-related interrupt occurred on that substream, call
169 	 * the DMA interrupt handler function, if one has been
170 	 * registered in the dma_params structure by the PCM driver.
171 	 */
172 	for (i = 0; i < ARRAY_SIZE(ssc_p->dma_params); i++) {
173 		dma_params = ssc_p->dma_params[i];
174 
175 		if ((dma_params != NULL) &&
176 			(dma_params->dma_intr_handler != NULL)) {
177 			ssc_substream_mask = (dma_params->mask->ssc_endx |
178 					dma_params->mask->ssc_endbuf);
179 			if (ssc_sr & ssc_substream_mask) {
180 				dma_params->dma_intr_handler(ssc_sr,
181 						dma_params->
182 						substream);
183 			}
184 		}
185 	}
186 
187 	return IRQ_HANDLED;
188 }
189 
190 
191 /*-------------------------------------------------------------------------*\
192  * DAI functions
193 \*-------------------------------------------------------------------------*/
194 /*
195  * Startup.  Only that one substream allowed in each direction.
196  */
197 static int atmel_ssc_startup(struct snd_pcm_substream *substream,
198 			     struct snd_soc_dai *dai)
199 {
200 	struct atmel_ssc_info *ssc_p = &ssc_info[dai->id];
201 	struct atmel_pcm_dma_params *dma_params;
202 	int dir, dir_mask;
203 
204 	pr_debug("atmel_ssc_startup: SSC_SR=0x%u\n",
205 		ssc_readl(ssc_p->ssc->regs, SR));
206 
207 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
208 		dir = 0;
209 		dir_mask = SSC_DIR_MASK_PLAYBACK;
210 	} else {
211 		dir = 1;
212 		dir_mask = SSC_DIR_MASK_CAPTURE;
213 	}
214 
215 	dma_params = &ssc_dma_params[dai->id][dir];
216 	dma_params->ssc = ssc_p->ssc;
217 	dma_params->substream = substream;
218 
219 	ssc_p->dma_params[dir] = dma_params;
220 
221 	snd_soc_dai_set_dma_data(dai, substream, dma_params);
222 
223 	spin_lock_irq(&ssc_p->lock);
224 	if (ssc_p->dir_mask & dir_mask) {
225 		spin_unlock_irq(&ssc_p->lock);
226 		return -EBUSY;
227 	}
228 	ssc_p->dir_mask |= dir_mask;
229 	spin_unlock_irq(&ssc_p->lock);
230 
231 	return 0;
232 }
233 
234 /*
235  * Shutdown.  Clear DMA parameters and shutdown the SSC if there
236  * are no other substreams open.
237  */
238 static void atmel_ssc_shutdown(struct snd_pcm_substream *substream,
239 			       struct snd_soc_dai *dai)
240 {
241 	struct atmel_ssc_info *ssc_p = &ssc_info[dai->id];
242 	struct atmel_pcm_dma_params *dma_params;
243 	int dir, dir_mask;
244 
245 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
246 		dir = 0;
247 	else
248 		dir = 1;
249 
250 	dma_params = ssc_p->dma_params[dir];
251 
252 	if (dma_params != NULL) {
253 		ssc_writel(ssc_p->ssc->regs, CR, dma_params->mask->ssc_disable);
254 		pr_debug("atmel_ssc_shutdown: %s disabled SSC_SR=0x%08x\n",
255 			(dir ? "receive" : "transmit"),
256 			ssc_readl(ssc_p->ssc->regs, SR));
257 
258 		dma_params->ssc = NULL;
259 		dma_params->substream = NULL;
260 		ssc_p->dma_params[dir] = NULL;
261 	}
262 
263 	dir_mask = 1 << dir;
264 
265 	spin_lock_irq(&ssc_p->lock);
266 	ssc_p->dir_mask &= ~dir_mask;
267 	if (!ssc_p->dir_mask) {
268 		if (ssc_p->initialized) {
269 			/* Shutdown the SSC clock. */
270 			pr_debug("atmel_ssc_dau: Stopping clock\n");
271 			clk_disable(ssc_p->ssc->clk);
272 
273 			free_irq(ssc_p->ssc->irq, ssc_p);
274 			ssc_p->initialized = 0;
275 		}
276 
277 		/* Reset the SSC */
278 		ssc_writel(ssc_p->ssc->regs, CR, SSC_BIT(CR_SWRST));
279 		/* Clear the SSC dividers */
280 		ssc_p->cmr_div = ssc_p->tcmr_period = ssc_p->rcmr_period = 0;
281 	}
282 	spin_unlock_irq(&ssc_p->lock);
283 }
284 
285 
286 /*
287  * Record the DAI format for use in hw_params().
288  */
289 static int atmel_ssc_set_dai_fmt(struct snd_soc_dai *cpu_dai,
290 		unsigned int fmt)
291 {
292 	struct atmel_ssc_info *ssc_p = &ssc_info[cpu_dai->id];
293 
294 	ssc_p->daifmt = fmt;
295 	return 0;
296 }
297 
298 /*
299  * Record SSC clock dividers for use in hw_params().
300  */
301 static int atmel_ssc_set_dai_clkdiv(struct snd_soc_dai *cpu_dai,
302 	int div_id, int div)
303 {
304 	struct atmel_ssc_info *ssc_p = &ssc_info[cpu_dai->id];
305 
306 	switch (div_id) {
307 	case ATMEL_SSC_CMR_DIV:
308 		/*
309 		 * The same master clock divider is used for both
310 		 * transmit and receive, so if a value has already
311 		 * been set, it must match this value.
312 		 */
313 		if (ssc_p->cmr_div == 0)
314 			ssc_p->cmr_div = div;
315 		else
316 			if (div != ssc_p->cmr_div)
317 				return -EBUSY;
318 		break;
319 
320 	case ATMEL_SSC_TCMR_PERIOD:
321 		ssc_p->tcmr_period = div;
322 		break;
323 
324 	case ATMEL_SSC_RCMR_PERIOD:
325 		ssc_p->rcmr_period = div;
326 		break;
327 
328 	default:
329 		return -EINVAL;
330 	}
331 
332 	return 0;
333 }
334 
335 /*
336  * Configure the SSC.
337  */
338 static int atmel_ssc_hw_params(struct snd_pcm_substream *substream,
339 	struct snd_pcm_hw_params *params,
340 	struct snd_soc_dai *dai)
341 {
342 	int id = dai->id;
343 	struct atmel_ssc_info *ssc_p = &ssc_info[id];
344 	struct atmel_pcm_dma_params *dma_params;
345 	int dir, channels, bits;
346 	u32 tfmr, rfmr, tcmr, rcmr;
347 	int start_event;
348 	int ret;
349 
350 	/*
351 	 * Currently, there is only one set of dma params for
352 	 * each direction.  If more are added, this code will
353 	 * have to be changed to select the proper set.
354 	 */
355 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
356 		dir = 0;
357 	else
358 		dir = 1;
359 
360 	dma_params = ssc_p->dma_params[dir];
361 
362 	channels = params_channels(params);
363 
364 	/*
365 	 * Determine sample size in bits and the PDC increment.
366 	 */
367 	switch (params_format(params)) {
368 	case SNDRV_PCM_FORMAT_S8:
369 		bits = 8;
370 		dma_params->pdc_xfer_size = 1;
371 		break;
372 	case SNDRV_PCM_FORMAT_S16_LE:
373 		bits = 16;
374 		dma_params->pdc_xfer_size = 2;
375 		break;
376 	case SNDRV_PCM_FORMAT_S24_LE:
377 		bits = 24;
378 		dma_params->pdc_xfer_size = 4;
379 		break;
380 	case SNDRV_PCM_FORMAT_S32_LE:
381 		bits = 32;
382 		dma_params->pdc_xfer_size = 4;
383 		break;
384 	default:
385 		printk(KERN_WARNING "atmel_ssc_dai: unsupported PCM format");
386 		return -EINVAL;
387 	}
388 
389 	/*
390 	 * The SSC only supports up to 16-bit samples in I2S format, due
391 	 * to the size of the Frame Mode Register FSLEN field.
392 	 */
393 	if ((ssc_p->daifmt & SND_SOC_DAIFMT_FORMAT_MASK) == SND_SOC_DAIFMT_I2S
394 		&& bits > 16) {
395 		printk(KERN_WARNING
396 				"atmel_ssc_dai: sample size %d "
397 				"is too large for I2S\n", bits);
398 		return -EINVAL;
399 	}
400 
401 	/*
402 	 * Compute SSC register settings.
403 	 */
404 	switch (ssc_p->daifmt
405 		& (SND_SOC_DAIFMT_FORMAT_MASK | SND_SOC_DAIFMT_MASTER_MASK)) {
406 
407 	case SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_CBS_CFS:
408 		/*
409 		 * I2S format, SSC provides BCLK and LRC clocks.
410 		 *
411 		 * The SSC transmit and receive clocks are generated
412 		 * from the MCK divider, and the BCLK signal
413 		 * is output on the SSC TK line.
414 		 */
415 		rcmr =	  SSC_BF(RCMR_PERIOD, ssc_p->rcmr_period)
416 			| SSC_BF(RCMR_STTDLY, START_DELAY)
417 			| SSC_BF(RCMR_START, SSC_START_FALLING_RF)
418 			| SSC_BF(RCMR_CKI, SSC_CKI_RISING)
419 			| SSC_BF(RCMR_CKO, SSC_CKO_NONE)
420 			| SSC_BF(RCMR_CKS, SSC_CKS_DIV);
421 
422 		rfmr =	  SSC_BF(RFMR_FSEDGE, SSC_FSEDGE_POSITIVE)
423 			| SSC_BF(RFMR_FSOS, SSC_FSOS_NEGATIVE)
424 			| SSC_BF(RFMR_FSLEN, (bits - 1))
425 			| SSC_BF(RFMR_DATNB, (channels - 1))
426 			| SSC_BIT(RFMR_MSBF)
427 			| SSC_BF(RFMR_LOOP, 0)
428 			| SSC_BF(RFMR_DATLEN, (bits - 1));
429 
430 		tcmr =	  SSC_BF(TCMR_PERIOD, ssc_p->tcmr_period)
431 			| SSC_BF(TCMR_STTDLY, START_DELAY)
432 			| SSC_BF(TCMR_START, SSC_START_FALLING_RF)
433 			| SSC_BF(TCMR_CKI, SSC_CKI_FALLING)
434 			| SSC_BF(TCMR_CKO, SSC_CKO_CONTINUOUS)
435 			| SSC_BF(TCMR_CKS, SSC_CKS_DIV);
436 
437 		tfmr =	  SSC_BF(TFMR_FSEDGE, SSC_FSEDGE_POSITIVE)
438 			| SSC_BF(TFMR_FSDEN, 0)
439 			| SSC_BF(TFMR_FSOS, SSC_FSOS_NEGATIVE)
440 			| SSC_BF(TFMR_FSLEN, (bits - 1))
441 			| SSC_BF(TFMR_DATNB, (channels - 1))
442 			| SSC_BIT(TFMR_MSBF)
443 			| SSC_BF(TFMR_DATDEF, 0)
444 			| SSC_BF(TFMR_DATLEN, (bits - 1));
445 		break;
446 
447 	case SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_CBM_CFM:
448 		/*
449 		 * I2S format, CODEC supplies BCLK and LRC clocks.
450 		 *
451 		 * The SSC transmit clock is obtained from the BCLK signal on
452 		 * on the TK line, and the SSC receive clock is
453 		 * generated from the transmit clock.
454 		 *
455 		 *  For single channel data, one sample is transferred
456 		 * on the falling edge of the LRC clock.
457 		 * For two channel data, one sample is
458 		 * transferred on both edges of the LRC clock.
459 		 */
460 		start_event = ((channels == 1)
461 				? SSC_START_FALLING_RF
462 				: SSC_START_EDGE_RF);
463 
464 		rcmr =	  SSC_BF(RCMR_PERIOD, 0)
465 			| SSC_BF(RCMR_STTDLY, START_DELAY)
466 			| SSC_BF(RCMR_START, start_event)
467 			| SSC_BF(RCMR_CKI, SSC_CKI_RISING)
468 			| SSC_BF(RCMR_CKO, SSC_CKO_NONE)
469 			| SSC_BF(RCMR_CKS, SSC_CKS_CLOCK);
470 
471 		rfmr =	  SSC_BF(RFMR_FSEDGE, SSC_FSEDGE_POSITIVE)
472 			| SSC_BF(RFMR_FSOS, SSC_FSOS_NONE)
473 			| SSC_BF(RFMR_FSLEN, 0)
474 			| SSC_BF(RFMR_DATNB, 0)
475 			| SSC_BIT(RFMR_MSBF)
476 			| SSC_BF(RFMR_LOOP, 0)
477 			| SSC_BF(RFMR_DATLEN, (bits - 1));
478 
479 		tcmr =	  SSC_BF(TCMR_PERIOD, 0)
480 			| SSC_BF(TCMR_STTDLY, START_DELAY)
481 			| SSC_BF(TCMR_START, start_event)
482 			| SSC_BF(TCMR_CKI, SSC_CKI_FALLING)
483 			| SSC_BF(TCMR_CKO, SSC_CKO_NONE)
484 			| SSC_BF(TCMR_CKS, SSC_CKS_PIN);
485 
486 		tfmr =	  SSC_BF(TFMR_FSEDGE, SSC_FSEDGE_POSITIVE)
487 			| SSC_BF(TFMR_FSDEN, 0)
488 			| SSC_BF(TFMR_FSOS, SSC_FSOS_NONE)
489 			| SSC_BF(TFMR_FSLEN, 0)
490 			| SSC_BF(TFMR_DATNB, 0)
491 			| SSC_BIT(TFMR_MSBF)
492 			| SSC_BF(TFMR_DATDEF, 0)
493 			| SSC_BF(TFMR_DATLEN, (bits - 1));
494 		break;
495 
496 	case SND_SOC_DAIFMT_DSP_A | SND_SOC_DAIFMT_CBS_CFS:
497 		/*
498 		 * DSP/PCM Mode A format, SSC provides BCLK and LRC clocks.
499 		 *
500 		 * The SSC transmit and receive clocks are generated from the
501 		 * MCK divider, and the BCLK signal is output
502 		 * on the SSC TK line.
503 		 */
504 		rcmr =	  SSC_BF(RCMR_PERIOD, ssc_p->rcmr_period)
505 			| SSC_BF(RCMR_STTDLY, 1)
506 			| SSC_BF(RCMR_START, SSC_START_RISING_RF)
507 			| SSC_BF(RCMR_CKI, SSC_CKI_RISING)
508 			| SSC_BF(RCMR_CKO, SSC_CKO_NONE)
509 			| SSC_BF(RCMR_CKS, SSC_CKS_DIV);
510 
511 		rfmr =	  SSC_BF(RFMR_FSEDGE, SSC_FSEDGE_POSITIVE)
512 			| SSC_BF(RFMR_FSOS, SSC_FSOS_POSITIVE)
513 			| SSC_BF(RFMR_FSLEN, 0)
514 			| SSC_BF(RFMR_DATNB, (channels - 1))
515 			| SSC_BIT(RFMR_MSBF)
516 			| SSC_BF(RFMR_LOOP, 0)
517 			| SSC_BF(RFMR_DATLEN, (bits - 1));
518 
519 		tcmr =	  SSC_BF(TCMR_PERIOD, ssc_p->tcmr_period)
520 			| SSC_BF(TCMR_STTDLY, 1)
521 			| SSC_BF(TCMR_START, SSC_START_RISING_RF)
522 			| SSC_BF(TCMR_CKI, SSC_CKI_RISING)
523 			| SSC_BF(TCMR_CKO, SSC_CKO_CONTINUOUS)
524 			| SSC_BF(TCMR_CKS, SSC_CKS_DIV);
525 
526 		tfmr =	  SSC_BF(TFMR_FSEDGE, SSC_FSEDGE_POSITIVE)
527 			| SSC_BF(TFMR_FSDEN, 0)
528 			| SSC_BF(TFMR_FSOS, SSC_FSOS_POSITIVE)
529 			| SSC_BF(TFMR_FSLEN, 0)
530 			| SSC_BF(TFMR_DATNB, (channels - 1))
531 			| SSC_BIT(TFMR_MSBF)
532 			| SSC_BF(TFMR_DATDEF, 0)
533 			| SSC_BF(TFMR_DATLEN, (bits - 1));
534 		break;
535 
536 	case SND_SOC_DAIFMT_DSP_A | SND_SOC_DAIFMT_CBM_CFM:
537 		/*
538 		 * DSP/PCM Mode A format, CODEC supplies BCLK and LRC clocks.
539 		 *
540 		 * The SSC transmit clock is obtained from the BCLK signal on
541 		 * on the TK line, and the SSC receive clock is
542 		 * generated from the transmit clock.
543 		 *
544 		 * Data is transferred on first BCLK after LRC pulse rising
545 		 * edge.If stereo, the right channel data is contiguous with
546 		 * the left channel data.
547 		 */
548 		rcmr =	  SSC_BF(RCMR_PERIOD, 0)
549 			| SSC_BF(RCMR_STTDLY, START_DELAY)
550 			| SSC_BF(RCMR_START, SSC_START_RISING_RF)
551 			| SSC_BF(RCMR_CKI, SSC_CKI_RISING)
552 			| SSC_BF(RCMR_CKO, SSC_CKO_NONE)
553 			| SSC_BF(RCMR_CKS, SSC_CKS_PIN);
554 
555 		rfmr =	  SSC_BF(RFMR_FSEDGE, SSC_FSEDGE_POSITIVE)
556 			| SSC_BF(RFMR_FSOS, SSC_FSOS_NONE)
557 			| SSC_BF(RFMR_FSLEN, 0)
558 			| SSC_BF(RFMR_DATNB, (channels - 1))
559 			| SSC_BIT(RFMR_MSBF)
560 			| SSC_BF(RFMR_LOOP, 0)
561 			| SSC_BF(RFMR_DATLEN, (bits - 1));
562 
563 		tcmr =	  SSC_BF(TCMR_PERIOD, 0)
564 			| SSC_BF(TCMR_STTDLY, START_DELAY)
565 			| SSC_BF(TCMR_START, SSC_START_RISING_RF)
566 			| SSC_BF(TCMR_CKI, SSC_CKI_FALLING)
567 			| SSC_BF(TCMR_CKO, SSC_CKO_NONE)
568 			| SSC_BF(TCMR_CKS, SSC_CKS_PIN);
569 
570 		tfmr =	  SSC_BF(TFMR_FSEDGE, SSC_FSEDGE_POSITIVE)
571 			| SSC_BF(TFMR_FSDEN, 0)
572 			| SSC_BF(TFMR_FSOS, SSC_FSOS_NONE)
573 			| SSC_BF(TFMR_FSLEN, 0)
574 			| SSC_BF(TFMR_DATNB, (channels - 1))
575 			| SSC_BIT(TFMR_MSBF)
576 			| SSC_BF(TFMR_DATDEF, 0)
577 			| SSC_BF(TFMR_DATLEN, (bits - 1));
578 		break;
579 
580 	default:
581 		printk(KERN_WARNING "atmel_ssc_dai: unsupported DAI format 0x%x\n",
582 			ssc_p->daifmt);
583 		return -EINVAL;
584 	}
585 	pr_debug("atmel_ssc_hw_params: "
586 			"RCMR=%08x RFMR=%08x TCMR=%08x TFMR=%08x\n",
587 			rcmr, rfmr, tcmr, tfmr);
588 
589 	if (!ssc_p->initialized) {
590 
591 		/* Enable PMC peripheral clock for this SSC */
592 		pr_debug("atmel_ssc_dai: Starting clock\n");
593 		clk_enable(ssc_p->ssc->clk);
594 
595 		/* Reset the SSC and its PDC registers */
596 		ssc_writel(ssc_p->ssc->regs, CR, SSC_BIT(CR_SWRST));
597 
598 		ssc_writel(ssc_p->ssc->regs, PDC_RPR, 0);
599 		ssc_writel(ssc_p->ssc->regs, PDC_RCR, 0);
600 		ssc_writel(ssc_p->ssc->regs, PDC_RNPR, 0);
601 		ssc_writel(ssc_p->ssc->regs, PDC_RNCR, 0);
602 
603 		ssc_writel(ssc_p->ssc->regs, PDC_TPR, 0);
604 		ssc_writel(ssc_p->ssc->regs, PDC_TCR, 0);
605 		ssc_writel(ssc_p->ssc->regs, PDC_TNPR, 0);
606 		ssc_writel(ssc_p->ssc->regs, PDC_TNCR, 0);
607 
608 		ret = request_irq(ssc_p->ssc->irq, atmel_ssc_interrupt, 0,
609 				ssc_p->name, ssc_p);
610 		if (ret < 0) {
611 			printk(KERN_WARNING
612 					"atmel_ssc_dai: request_irq failure\n");
613 			pr_debug("Atmel_ssc_dai: Stoping clock\n");
614 			clk_disable(ssc_p->ssc->clk);
615 			return ret;
616 		}
617 
618 		ssc_p->initialized = 1;
619 	}
620 
621 	/* set SSC clock mode register */
622 	ssc_writel(ssc_p->ssc->regs, CMR, ssc_p->cmr_div);
623 
624 	/* set receive clock mode and format */
625 	ssc_writel(ssc_p->ssc->regs, RCMR, rcmr);
626 	ssc_writel(ssc_p->ssc->regs, RFMR, rfmr);
627 
628 	/* set transmit clock mode and format */
629 	ssc_writel(ssc_p->ssc->regs, TCMR, tcmr);
630 	ssc_writel(ssc_p->ssc->regs, TFMR, tfmr);
631 
632 	pr_debug("atmel_ssc_dai,hw_params: SSC initialized\n");
633 	return 0;
634 }
635 
636 
637 static int atmel_ssc_prepare(struct snd_pcm_substream *substream,
638 			     struct snd_soc_dai *dai)
639 {
640 	struct atmel_ssc_info *ssc_p = &ssc_info[dai->id];
641 	struct atmel_pcm_dma_params *dma_params;
642 	int dir;
643 
644 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
645 		dir = 0;
646 	else
647 		dir = 1;
648 
649 	dma_params = ssc_p->dma_params[dir];
650 
651 	ssc_writel(ssc_p->ssc->regs, CR, dma_params->mask->ssc_enable);
652 	ssc_writel(ssc_p->ssc->regs, IDR, dma_params->mask->ssc_error);
653 
654 	pr_debug("%s enabled SSC_SR=0x%08x\n",
655 			dir ? "receive" : "transmit",
656 			ssc_readl(ssc_p->ssc->regs, SR));
657 	return 0;
658 }
659 
660 
661 #ifdef CONFIG_PM
662 static int atmel_ssc_suspend(struct snd_soc_dai *cpu_dai)
663 {
664 	struct atmel_ssc_info *ssc_p;
665 
666 	if (!cpu_dai->active)
667 		return 0;
668 
669 	ssc_p = &ssc_info[cpu_dai->id];
670 
671 	/* Save the status register before disabling transmit and receive */
672 	ssc_p->ssc_state.ssc_sr = ssc_readl(ssc_p->ssc->regs, SR);
673 	ssc_writel(ssc_p->ssc->regs, CR, SSC_BIT(CR_TXDIS) | SSC_BIT(CR_RXDIS));
674 
675 	/* Save the current interrupt mask, then disable unmasked interrupts */
676 	ssc_p->ssc_state.ssc_imr = ssc_readl(ssc_p->ssc->regs, IMR);
677 	ssc_writel(ssc_p->ssc->regs, IDR, ssc_p->ssc_state.ssc_imr);
678 
679 	ssc_p->ssc_state.ssc_cmr = ssc_readl(ssc_p->ssc->regs, CMR);
680 	ssc_p->ssc_state.ssc_rcmr = ssc_readl(ssc_p->ssc->regs, RCMR);
681 	ssc_p->ssc_state.ssc_rfmr = ssc_readl(ssc_p->ssc->regs, RFMR);
682 	ssc_p->ssc_state.ssc_tcmr = ssc_readl(ssc_p->ssc->regs, TCMR);
683 	ssc_p->ssc_state.ssc_tfmr = ssc_readl(ssc_p->ssc->regs, TFMR);
684 
685 	return 0;
686 }
687 
688 
689 
690 static int atmel_ssc_resume(struct snd_soc_dai *cpu_dai)
691 {
692 	struct atmel_ssc_info *ssc_p;
693 	u32 cr;
694 
695 	if (!cpu_dai->active)
696 		return 0;
697 
698 	ssc_p = &ssc_info[cpu_dai->id];
699 
700 	/* restore SSC register settings */
701 	ssc_writel(ssc_p->ssc->regs, TFMR, ssc_p->ssc_state.ssc_tfmr);
702 	ssc_writel(ssc_p->ssc->regs, TCMR, ssc_p->ssc_state.ssc_tcmr);
703 	ssc_writel(ssc_p->ssc->regs, RFMR, ssc_p->ssc_state.ssc_rfmr);
704 	ssc_writel(ssc_p->ssc->regs, RCMR, ssc_p->ssc_state.ssc_rcmr);
705 	ssc_writel(ssc_p->ssc->regs, CMR, ssc_p->ssc_state.ssc_cmr);
706 
707 	/* re-enable interrupts */
708 	ssc_writel(ssc_p->ssc->regs, IER, ssc_p->ssc_state.ssc_imr);
709 
710 	/* Re-enable receive and transmit as appropriate */
711 	cr = 0;
712 	cr |=
713 	    (ssc_p->ssc_state.ssc_sr & SSC_BIT(SR_RXEN)) ? SSC_BIT(CR_RXEN) : 0;
714 	cr |=
715 	    (ssc_p->ssc_state.ssc_sr & SSC_BIT(SR_TXEN)) ? SSC_BIT(CR_TXEN) : 0;
716 	ssc_writel(ssc_p->ssc->regs, CR, cr);
717 
718 	return 0;
719 }
720 #else /* CONFIG_PM */
721 #  define atmel_ssc_suspend	NULL
722 #  define atmel_ssc_resume	NULL
723 #endif /* CONFIG_PM */
724 
725 #define ATMEL_SSC_RATES (SNDRV_PCM_RATE_8000_96000)
726 
727 #define ATMEL_SSC_FORMATS (SNDRV_PCM_FMTBIT_S8     | SNDRV_PCM_FMTBIT_S16_LE |\
728 			  SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S32_LE)
729 
730 static const struct snd_soc_dai_ops atmel_ssc_dai_ops = {
731 	.startup	= atmel_ssc_startup,
732 	.shutdown	= atmel_ssc_shutdown,
733 	.prepare	= atmel_ssc_prepare,
734 	.hw_params	= atmel_ssc_hw_params,
735 	.set_fmt	= atmel_ssc_set_dai_fmt,
736 	.set_clkdiv	= atmel_ssc_set_dai_clkdiv,
737 };
738 
739 static struct snd_soc_dai_driver atmel_ssc_dai = {
740 		.suspend = atmel_ssc_suspend,
741 		.resume = atmel_ssc_resume,
742 		.playback = {
743 			.channels_min = 1,
744 			.channels_max = 2,
745 			.rates = ATMEL_SSC_RATES,
746 			.formats = ATMEL_SSC_FORMATS,},
747 		.capture = {
748 			.channels_min = 1,
749 			.channels_max = 2,
750 			.rates = ATMEL_SSC_RATES,
751 			.formats = ATMEL_SSC_FORMATS,},
752 		.ops = &atmel_ssc_dai_ops,
753 };
754 
755 static const struct snd_soc_component_driver atmel_ssc_component = {
756 	.name		= "atmel-ssc",
757 };
758 
759 static int asoc_ssc_init(struct device *dev)
760 {
761 	struct platform_device *pdev = to_platform_device(dev);
762 	struct ssc_device *ssc = platform_get_drvdata(pdev);
763 	int ret;
764 
765 	ret = snd_soc_register_component(dev, &atmel_ssc_component,
766 					 &atmel_ssc_dai, 1);
767 	if (ret) {
768 		dev_err(dev, "Could not register DAI: %d\n", ret);
769 		goto err;
770 	}
771 
772 	if (ssc->pdata->use_dma)
773 		ret = atmel_pcm_dma_platform_register(dev);
774 	else
775 		ret = atmel_pcm_pdc_platform_register(dev);
776 
777 	if (ret) {
778 		dev_err(dev, "Could not register PCM: %d\n", ret);
779 		goto err_unregister_dai;
780 	};
781 
782 	return 0;
783 
784 err_unregister_dai:
785 	snd_soc_unregister_component(dev);
786 err:
787 	return ret;
788 }
789 
790 static void asoc_ssc_exit(struct device *dev)
791 {
792 	struct platform_device *pdev = to_platform_device(dev);
793 	struct ssc_device *ssc = platform_get_drvdata(pdev);
794 
795 	if (ssc->pdata->use_dma)
796 		atmel_pcm_dma_platform_unregister(dev);
797 	else
798 		atmel_pcm_pdc_platform_unregister(dev);
799 
800 	snd_soc_unregister_component(dev);
801 }
802 
803 /**
804  * atmel_ssc_set_audio - Allocate the specified SSC for audio use.
805  */
806 int atmel_ssc_set_audio(int ssc_id)
807 {
808 	struct ssc_device *ssc;
809 	int ret;
810 
811 	/* If we can grab the SSC briefly to parent the DAI device off it */
812 	ssc = ssc_request(ssc_id);
813 	if (IS_ERR(ssc)) {
814 		pr_err("Unable to parent ASoC SSC DAI on SSC: %ld\n",
815 			PTR_ERR(ssc));
816 		return PTR_ERR(ssc);
817 	} else {
818 		ssc_info[ssc_id].ssc = ssc;
819 	}
820 
821 	ret = asoc_ssc_init(&ssc->pdev->dev);
822 
823 	return ret;
824 }
825 EXPORT_SYMBOL_GPL(atmel_ssc_set_audio);
826 
827 void atmel_ssc_put_audio(int ssc_id)
828 {
829 	struct ssc_device *ssc = ssc_info[ssc_id].ssc;
830 
831 	asoc_ssc_exit(&ssc->pdev->dev);
832 	ssc_free(ssc);
833 }
834 EXPORT_SYMBOL_GPL(atmel_ssc_put_audio);
835 
836 /* Module information */
837 MODULE_AUTHOR("Sedji Gaouaou, sedji.gaouaou@atmel.com, www.atmel.com");
838 MODULE_DESCRIPTION("ATMEL SSC ASoC Interface");
839 MODULE_LICENSE("GPL");
840