xref: /openbmc/linux/sound/soc/atmel/atmel_ssc_dai.c (revision 63705da3)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * atmel_ssc_dai.c  --  ALSA SoC ATMEL SSC Audio Layer Platform driver
4  *
5  * Copyright (C) 2005 SAN People
6  * Copyright (C) 2008 Atmel
7  *
8  * Author: Sedji Gaouaou <sedji.gaouaou@atmel.com>
9  *         ATMEL CORP.
10  *
11  * Based on at91-ssc.c by
12  * Frank Mandarino <fmandarino@endrelia.com>
13  * Based on pxa2xx Platform drivers by
14  * Liam Girdwood <lrg@slimlogic.co.uk>
15  */
16 
17 #include <linux/init.h>
18 #include <linux/module.h>
19 #include <linux/interrupt.h>
20 #include <linux/device.h>
21 #include <linux/delay.h>
22 #include <linux/clk.h>
23 #include <linux/atmel_pdc.h>
24 
25 #include <linux/atmel-ssc.h>
26 #include <sound/core.h>
27 #include <sound/pcm.h>
28 #include <sound/pcm_params.h>
29 #include <sound/initval.h>
30 #include <sound/soc.h>
31 
32 #include "atmel-pcm.h"
33 #include "atmel_ssc_dai.h"
34 
35 
36 #define NUM_SSC_DEVICES		3
37 
38 /*
39  * SSC PDC registers required by the PCM DMA engine.
40  */
41 static struct atmel_pdc_regs pdc_tx_reg = {
42 	.xpr		= ATMEL_PDC_TPR,
43 	.xcr		= ATMEL_PDC_TCR,
44 	.xnpr		= ATMEL_PDC_TNPR,
45 	.xncr		= ATMEL_PDC_TNCR,
46 };
47 
48 static struct atmel_pdc_regs pdc_rx_reg = {
49 	.xpr		= ATMEL_PDC_RPR,
50 	.xcr		= ATMEL_PDC_RCR,
51 	.xnpr		= ATMEL_PDC_RNPR,
52 	.xncr		= ATMEL_PDC_RNCR,
53 };
54 
55 /*
56  * SSC & PDC status bits for transmit and receive.
57  */
58 static struct atmel_ssc_mask ssc_tx_mask = {
59 	.ssc_enable	= SSC_BIT(CR_TXEN),
60 	.ssc_disable	= SSC_BIT(CR_TXDIS),
61 	.ssc_endx	= SSC_BIT(SR_ENDTX),
62 	.ssc_endbuf	= SSC_BIT(SR_TXBUFE),
63 	.ssc_error	= SSC_BIT(SR_OVRUN),
64 	.pdc_enable	= ATMEL_PDC_TXTEN,
65 	.pdc_disable	= ATMEL_PDC_TXTDIS,
66 };
67 
68 static struct atmel_ssc_mask ssc_rx_mask = {
69 	.ssc_enable	= SSC_BIT(CR_RXEN),
70 	.ssc_disable	= SSC_BIT(CR_RXDIS),
71 	.ssc_endx	= SSC_BIT(SR_ENDRX),
72 	.ssc_endbuf	= SSC_BIT(SR_RXBUFF),
73 	.ssc_error	= SSC_BIT(SR_OVRUN),
74 	.pdc_enable	= ATMEL_PDC_RXTEN,
75 	.pdc_disable	= ATMEL_PDC_RXTDIS,
76 };
77 
78 
79 /*
80  * DMA parameters.
81  */
82 static struct atmel_pcm_dma_params ssc_dma_params[NUM_SSC_DEVICES][2] = {
83 	{{
84 	.name		= "SSC0 PCM out",
85 	.pdc		= &pdc_tx_reg,
86 	.mask		= &ssc_tx_mask,
87 	},
88 	{
89 	.name		= "SSC0 PCM in",
90 	.pdc		= &pdc_rx_reg,
91 	.mask		= &ssc_rx_mask,
92 	} },
93 	{{
94 	.name		= "SSC1 PCM out",
95 	.pdc		= &pdc_tx_reg,
96 	.mask		= &ssc_tx_mask,
97 	},
98 	{
99 	.name		= "SSC1 PCM in",
100 	.pdc		= &pdc_rx_reg,
101 	.mask		= &ssc_rx_mask,
102 	} },
103 	{{
104 	.name		= "SSC2 PCM out",
105 	.pdc		= &pdc_tx_reg,
106 	.mask		= &ssc_tx_mask,
107 	},
108 	{
109 	.name		= "SSC2 PCM in",
110 	.pdc		= &pdc_rx_reg,
111 	.mask		= &ssc_rx_mask,
112 	} },
113 };
114 
115 
116 static struct atmel_ssc_info ssc_info[NUM_SSC_DEVICES] = {
117 	{
118 	.name		= "ssc0",
119 	.dir_mask	= SSC_DIR_MASK_UNUSED,
120 	.initialized	= 0,
121 	},
122 	{
123 	.name		= "ssc1",
124 	.dir_mask	= SSC_DIR_MASK_UNUSED,
125 	.initialized	= 0,
126 	},
127 	{
128 	.name		= "ssc2",
129 	.dir_mask	= SSC_DIR_MASK_UNUSED,
130 	.initialized	= 0,
131 	},
132 };
133 
134 
135 /*
136  * SSC interrupt handler.  Passes PDC interrupts to the DMA
137  * interrupt handler in the PCM driver.
138  */
139 static irqreturn_t atmel_ssc_interrupt(int irq, void *dev_id)
140 {
141 	struct atmel_ssc_info *ssc_p = dev_id;
142 	struct atmel_pcm_dma_params *dma_params;
143 	u32 ssc_sr;
144 	u32 ssc_substream_mask;
145 	int i;
146 
147 	ssc_sr = (unsigned long)ssc_readl(ssc_p->ssc->regs, SR)
148 			& (unsigned long)ssc_readl(ssc_p->ssc->regs, IMR);
149 
150 	/*
151 	 * Loop through the substreams attached to this SSC.  If
152 	 * a DMA-related interrupt occurred on that substream, call
153 	 * the DMA interrupt handler function, if one has been
154 	 * registered in the dma_params structure by the PCM driver.
155 	 */
156 	for (i = 0; i < ARRAY_SIZE(ssc_p->dma_params); i++) {
157 		dma_params = ssc_p->dma_params[i];
158 
159 		if ((dma_params != NULL) &&
160 			(dma_params->dma_intr_handler != NULL)) {
161 			ssc_substream_mask = (dma_params->mask->ssc_endx |
162 					dma_params->mask->ssc_endbuf);
163 			if (ssc_sr & ssc_substream_mask) {
164 				dma_params->dma_intr_handler(ssc_sr,
165 						dma_params->
166 						substream);
167 			}
168 		}
169 	}
170 
171 	return IRQ_HANDLED;
172 }
173 
174 /*
175  * When the bit clock is input, limit the maximum rate according to the
176  * Serial Clock Ratio Considerations section from the SSC documentation:
177  *
178  *   The Transmitter and the Receiver can be programmed to operate
179  *   with the clock signals provided on either the TK or RK pins.
180  *   This allows the SSC to support many slave-mode data transfers.
181  *   In this case, the maximum clock speed allowed on the RK pin is:
182  *   - Peripheral clock divided by 2 if Receiver Frame Synchro is input
183  *   - Peripheral clock divided by 3 if Receiver Frame Synchro is output
184  *   In addition, the maximum clock speed allowed on the TK pin is:
185  *   - Peripheral clock divided by 6 if Transmit Frame Synchro is input
186  *   - Peripheral clock divided by 2 if Transmit Frame Synchro is output
187  *
188  * When the bit clock is output, limit the rate according to the
189  * SSC divider restrictions.
190  */
191 static int atmel_ssc_hw_rule_rate(struct snd_pcm_hw_params *params,
192 				  struct snd_pcm_hw_rule *rule)
193 {
194 	struct atmel_ssc_info *ssc_p = rule->private;
195 	struct ssc_device *ssc = ssc_p->ssc;
196 	struct snd_interval *i = hw_param_interval(params, rule->var);
197 	struct snd_interval t;
198 	struct snd_ratnum r = {
199 		.den_min = 1,
200 		.den_max = 4095,
201 		.den_step = 1,
202 	};
203 	unsigned int num = 0, den = 0;
204 	int frame_size;
205 	int mck_div = 2;
206 	int ret;
207 
208 	frame_size = snd_soc_params_to_frame_size(params);
209 	if (frame_size < 0)
210 		return frame_size;
211 
212 	switch (ssc_p->daifmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK) {
213 	case SND_SOC_DAIFMT_CBP_CFC:
214 		if ((ssc_p->dir_mask & SSC_DIR_MASK_CAPTURE)
215 		    && ssc->clk_from_rk_pin)
216 			/* Receiver Frame Synchro (i.e. capture)
217 			 * is output (format is _CFS) and the RK pin
218 			 * is used for input (format is _CBM_).
219 			 */
220 			mck_div = 3;
221 		break;
222 
223 	case SND_SOC_DAIFMT_CBP_CFP:
224 		if ((ssc_p->dir_mask & SSC_DIR_MASK_PLAYBACK)
225 		    && !ssc->clk_from_rk_pin)
226 			/* Transmit Frame Synchro (i.e. playback)
227 			 * is input (format is _CFM) and the TK pin
228 			 * is used for input (format _CBM_ but not
229 			 * using the RK pin).
230 			 */
231 			mck_div = 6;
232 		break;
233 	}
234 
235 	switch (ssc_p->daifmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK) {
236 	case SND_SOC_DAIFMT_CBC_CFC:
237 		r.num = ssc_p->mck_rate / mck_div / frame_size;
238 
239 		ret = snd_interval_ratnum(i, 1, &r, &num, &den);
240 		if (ret >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
241 			params->rate_num = num;
242 			params->rate_den = den;
243 		}
244 		break;
245 
246 	case SND_SOC_DAIFMT_CBP_CFC:
247 	case SND_SOC_DAIFMT_CBP_CFP:
248 		t.min = 8000;
249 		t.max = ssc_p->mck_rate / mck_div / frame_size;
250 		t.openmin = t.openmax = 0;
251 		t.integer = 0;
252 		ret = snd_interval_refine(i, &t);
253 		break;
254 
255 	default:
256 		ret = -EINVAL;
257 		break;
258 	}
259 
260 	return ret;
261 }
262 
263 /*-------------------------------------------------------------------------*\
264  * DAI functions
265 \*-------------------------------------------------------------------------*/
266 /*
267  * Startup.  Only that one substream allowed in each direction.
268  */
269 static int atmel_ssc_startup(struct snd_pcm_substream *substream,
270 			     struct snd_soc_dai *dai)
271 {
272 	struct platform_device *pdev = to_platform_device(dai->dev);
273 	struct atmel_ssc_info *ssc_p = &ssc_info[pdev->id];
274 	struct atmel_pcm_dma_params *dma_params;
275 	int dir, dir_mask;
276 	int ret;
277 
278 	pr_debug("atmel_ssc_startup: SSC_SR=0x%x\n",
279 		ssc_readl(ssc_p->ssc->regs, SR));
280 
281 	/* Enable PMC peripheral clock for this SSC */
282 	pr_debug("atmel_ssc_dai: Starting clock\n");
283 	clk_enable(ssc_p->ssc->clk);
284 	ssc_p->mck_rate = clk_get_rate(ssc_p->ssc->clk);
285 
286 	/* Reset the SSC unless initialized to keep it in a clean state */
287 	if (!ssc_p->initialized)
288 		ssc_writel(ssc_p->ssc->regs, CR, SSC_BIT(CR_SWRST));
289 
290 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
291 		dir = 0;
292 		dir_mask = SSC_DIR_MASK_PLAYBACK;
293 	} else {
294 		dir = 1;
295 		dir_mask = SSC_DIR_MASK_CAPTURE;
296 	}
297 
298 	ret = snd_pcm_hw_rule_add(substream->runtime, 0,
299 				  SNDRV_PCM_HW_PARAM_RATE,
300 				  atmel_ssc_hw_rule_rate,
301 				  ssc_p,
302 				  SNDRV_PCM_HW_PARAM_FRAME_BITS,
303 				  SNDRV_PCM_HW_PARAM_CHANNELS, -1);
304 	if (ret < 0) {
305 		dev_err(dai->dev, "Failed to specify rate rule: %d\n", ret);
306 		return ret;
307 	}
308 
309 	dma_params = &ssc_dma_params[pdev->id][dir];
310 	dma_params->ssc = ssc_p->ssc;
311 	dma_params->substream = substream;
312 
313 	ssc_p->dma_params[dir] = dma_params;
314 
315 	snd_soc_dai_set_dma_data(dai, substream, dma_params);
316 
317 	if (ssc_p->dir_mask & dir_mask)
318 		return -EBUSY;
319 
320 	ssc_p->dir_mask |= dir_mask;
321 
322 	return 0;
323 }
324 
325 /*
326  * Shutdown.  Clear DMA parameters and shutdown the SSC if there
327  * are no other substreams open.
328  */
329 static void atmel_ssc_shutdown(struct snd_pcm_substream *substream,
330 			       struct snd_soc_dai *dai)
331 {
332 	struct platform_device *pdev = to_platform_device(dai->dev);
333 	struct atmel_ssc_info *ssc_p = &ssc_info[pdev->id];
334 	struct atmel_pcm_dma_params *dma_params;
335 	int dir, dir_mask;
336 
337 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
338 		dir = 0;
339 	else
340 		dir = 1;
341 
342 	dma_params = ssc_p->dma_params[dir];
343 
344 	if (dma_params != NULL) {
345 		dma_params->ssc = NULL;
346 		dma_params->substream = NULL;
347 		ssc_p->dma_params[dir] = NULL;
348 	}
349 
350 	dir_mask = 1 << dir;
351 
352 	ssc_p->dir_mask &= ~dir_mask;
353 	if (!ssc_p->dir_mask) {
354 		if (ssc_p->initialized) {
355 			free_irq(ssc_p->ssc->irq, ssc_p);
356 			ssc_p->initialized = 0;
357 		}
358 
359 		/* Reset the SSC */
360 		ssc_writel(ssc_p->ssc->regs, CR, SSC_BIT(CR_SWRST));
361 		/* Clear the SSC dividers */
362 		ssc_p->cmr_div = ssc_p->tcmr_period = ssc_p->rcmr_period = 0;
363 		ssc_p->forced_divider = 0;
364 	}
365 
366 	/* Shutdown the SSC clock. */
367 	pr_debug("atmel_ssc_dai: Stopping clock\n");
368 	clk_disable(ssc_p->ssc->clk);
369 }
370 
371 
372 /*
373  * Record the DAI format for use in hw_params().
374  */
375 static int atmel_ssc_set_dai_fmt(struct snd_soc_dai *cpu_dai,
376 		unsigned int fmt)
377 {
378 	struct platform_device *pdev = to_platform_device(cpu_dai->dev);
379 	struct atmel_ssc_info *ssc_p = &ssc_info[pdev->id];
380 
381 	ssc_p->daifmt = fmt;
382 	return 0;
383 }
384 
385 /*
386  * Record SSC clock dividers for use in hw_params().
387  */
388 static int atmel_ssc_set_dai_clkdiv(struct snd_soc_dai *cpu_dai,
389 	int div_id, int div)
390 {
391 	struct platform_device *pdev = to_platform_device(cpu_dai->dev);
392 	struct atmel_ssc_info *ssc_p = &ssc_info[pdev->id];
393 
394 	switch (div_id) {
395 	case ATMEL_SSC_CMR_DIV:
396 		/*
397 		 * The same master clock divider is used for both
398 		 * transmit and receive, so if a value has already
399 		 * been set, it must match this value.
400 		 */
401 		if (ssc_p->dir_mask !=
402 			(SSC_DIR_MASK_PLAYBACK | SSC_DIR_MASK_CAPTURE))
403 			ssc_p->cmr_div = div;
404 		else if (ssc_p->cmr_div == 0)
405 			ssc_p->cmr_div = div;
406 		else
407 			if (div != ssc_p->cmr_div)
408 				return -EBUSY;
409 		ssc_p->forced_divider |= BIT(ATMEL_SSC_CMR_DIV);
410 		break;
411 
412 	case ATMEL_SSC_TCMR_PERIOD:
413 		ssc_p->tcmr_period = div;
414 		ssc_p->forced_divider |= BIT(ATMEL_SSC_TCMR_PERIOD);
415 		break;
416 
417 	case ATMEL_SSC_RCMR_PERIOD:
418 		ssc_p->rcmr_period = div;
419 		ssc_p->forced_divider |= BIT(ATMEL_SSC_RCMR_PERIOD);
420 		break;
421 
422 	default:
423 		return -EINVAL;
424 	}
425 
426 	return 0;
427 }
428 
429 /* Is the cpu-dai master of the frame clock? */
430 static int atmel_ssc_cfs(struct atmel_ssc_info *ssc_p)
431 {
432 	switch (ssc_p->daifmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK) {
433 	case SND_SOC_DAIFMT_CBP_CFC:
434 	case SND_SOC_DAIFMT_CBC_CFC:
435 		return 1;
436 	}
437 	return 0;
438 }
439 
440 /* Is the cpu-dai master of the bit clock? */
441 static int atmel_ssc_cbs(struct atmel_ssc_info *ssc_p)
442 {
443 	switch (ssc_p->daifmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK) {
444 	case SND_SOC_DAIFMT_CBC_CFP:
445 	case SND_SOC_DAIFMT_CBC_CFC:
446 		return 1;
447 	}
448 	return 0;
449 }
450 
451 /*
452  * Configure the SSC.
453  */
454 static int atmel_ssc_hw_params(struct snd_pcm_substream *substream,
455 	struct snd_pcm_hw_params *params,
456 	struct snd_soc_dai *dai)
457 {
458 	struct platform_device *pdev = to_platform_device(dai->dev);
459 	int id = pdev->id;
460 	struct atmel_ssc_info *ssc_p = &ssc_info[id];
461 	struct ssc_device *ssc = ssc_p->ssc;
462 	struct atmel_pcm_dma_params *dma_params;
463 	int dir, channels, bits;
464 	u32 tfmr, rfmr, tcmr, rcmr;
465 	int ret;
466 	int fslen, fslen_ext, fs_osync, fs_edge;
467 	u32 cmr_div;
468 	u32 tcmr_period;
469 	u32 rcmr_period;
470 
471 	/*
472 	 * Currently, there is only one set of dma params for
473 	 * each direction.  If more are added, this code will
474 	 * have to be changed to select the proper set.
475 	 */
476 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
477 		dir = 0;
478 	else
479 		dir = 1;
480 
481 	/*
482 	 * If the cpu dai should provide BCLK, but noone has provided the
483 	 * divider needed for that to work, fall back to something sensible.
484 	 */
485 	cmr_div = ssc_p->cmr_div;
486 	if (!(ssc_p->forced_divider & BIT(ATMEL_SSC_CMR_DIV)) &&
487 	    atmel_ssc_cbs(ssc_p)) {
488 		int bclk_rate = snd_soc_params_to_bclk(params);
489 
490 		if (bclk_rate < 0) {
491 			dev_err(dai->dev, "unable to calculate cmr_div: %d\n",
492 				bclk_rate);
493 			return bclk_rate;
494 		}
495 
496 		cmr_div = DIV_ROUND_CLOSEST(ssc_p->mck_rate, 2 * bclk_rate);
497 	}
498 
499 	/*
500 	 * If the cpu dai should provide LRCLK, but noone has provided the
501 	 * dividers needed for that to work, fall back to something sensible.
502 	 */
503 	tcmr_period = ssc_p->tcmr_period;
504 	rcmr_period = ssc_p->rcmr_period;
505 	if (atmel_ssc_cfs(ssc_p)) {
506 		int frame_size = snd_soc_params_to_frame_size(params);
507 
508 		if (frame_size < 0) {
509 			dev_err(dai->dev,
510 				"unable to calculate tx/rx cmr_period: %d\n",
511 				frame_size);
512 			return frame_size;
513 		}
514 
515 		if (!(ssc_p->forced_divider & BIT(ATMEL_SSC_TCMR_PERIOD)))
516 			tcmr_period = frame_size / 2 - 1;
517 		if (!(ssc_p->forced_divider & BIT(ATMEL_SSC_RCMR_PERIOD)))
518 			rcmr_period = frame_size / 2 - 1;
519 	}
520 
521 	dma_params = ssc_p->dma_params[dir];
522 
523 	channels = params_channels(params);
524 
525 	/*
526 	 * Determine sample size in bits and the PDC increment.
527 	 */
528 	switch (params_format(params)) {
529 	case SNDRV_PCM_FORMAT_S8:
530 		bits = 8;
531 		dma_params->pdc_xfer_size = 1;
532 		break;
533 	case SNDRV_PCM_FORMAT_S16_LE:
534 		bits = 16;
535 		dma_params->pdc_xfer_size = 2;
536 		break;
537 	case SNDRV_PCM_FORMAT_S24_LE:
538 		bits = 24;
539 		dma_params->pdc_xfer_size = 4;
540 		break;
541 	case SNDRV_PCM_FORMAT_S32_LE:
542 		bits = 32;
543 		dma_params->pdc_xfer_size = 4;
544 		break;
545 	default:
546 		printk(KERN_WARNING "atmel_ssc_dai: unsupported PCM format");
547 		return -EINVAL;
548 	}
549 
550 	/*
551 	 * Compute SSC register settings.
552 	 */
553 
554 	fslen_ext = (bits - 1) / 16;
555 	fslen = (bits - 1) % 16;
556 
557 	switch (ssc_p->daifmt & SND_SOC_DAIFMT_FORMAT_MASK) {
558 
559 	case SND_SOC_DAIFMT_LEFT_J:
560 		fs_osync = SSC_FSOS_POSITIVE;
561 		fs_edge = SSC_START_RISING_RF;
562 
563 		rcmr =	  SSC_BF(RCMR_STTDLY, 0);
564 		tcmr =	  SSC_BF(TCMR_STTDLY, 0);
565 
566 		break;
567 
568 	case SND_SOC_DAIFMT_I2S:
569 		fs_osync = SSC_FSOS_NEGATIVE;
570 		fs_edge = SSC_START_FALLING_RF;
571 
572 		rcmr =	  SSC_BF(RCMR_STTDLY, 1);
573 		tcmr =	  SSC_BF(TCMR_STTDLY, 1);
574 
575 		break;
576 
577 	case SND_SOC_DAIFMT_DSP_A:
578 		/*
579 		 * DSP/PCM Mode A format
580 		 *
581 		 * Data is transferred on first BCLK after LRC pulse rising
582 		 * edge.If stereo, the right channel data is contiguous with
583 		 * the left channel data.
584 		 */
585 		fs_osync = SSC_FSOS_POSITIVE;
586 		fs_edge = SSC_START_RISING_RF;
587 		fslen = fslen_ext = 0;
588 
589 		rcmr =	  SSC_BF(RCMR_STTDLY, 1);
590 		tcmr =	  SSC_BF(TCMR_STTDLY, 1);
591 
592 		break;
593 
594 	default:
595 		printk(KERN_WARNING "atmel_ssc_dai: unsupported DAI format 0x%x\n",
596 			ssc_p->daifmt);
597 		return -EINVAL;
598 	}
599 
600 	if (!atmel_ssc_cfs(ssc_p)) {
601 		fslen = fslen_ext = 0;
602 		rcmr_period = tcmr_period = 0;
603 		fs_osync = SSC_FSOS_NONE;
604 	}
605 
606 	rcmr |=	  SSC_BF(RCMR_START, fs_edge);
607 	tcmr |=	  SSC_BF(TCMR_START, fs_edge);
608 
609 	if (atmel_ssc_cbs(ssc_p)) {
610 		/*
611 		 * SSC provides BCLK
612 		 *
613 		 * The SSC transmit and receive clocks are generated from the
614 		 * MCK divider, and the BCLK signal is output
615 		 * on the SSC TK line.
616 		 */
617 		rcmr |=	  SSC_BF(RCMR_CKS, SSC_CKS_DIV)
618 			| SSC_BF(RCMR_CKO, SSC_CKO_NONE);
619 
620 		tcmr |=	  SSC_BF(TCMR_CKS, SSC_CKS_DIV)
621 			| SSC_BF(TCMR_CKO, SSC_CKO_CONTINUOUS);
622 	} else {
623 		rcmr |=	  SSC_BF(RCMR_CKS, ssc->clk_from_rk_pin ?
624 					SSC_CKS_PIN : SSC_CKS_CLOCK)
625 			| SSC_BF(RCMR_CKO, SSC_CKO_NONE);
626 
627 		tcmr |=	  SSC_BF(TCMR_CKS, ssc->clk_from_rk_pin ?
628 					SSC_CKS_CLOCK : SSC_CKS_PIN)
629 			| SSC_BF(TCMR_CKO, SSC_CKO_NONE);
630 	}
631 
632 	rcmr |=	  SSC_BF(RCMR_PERIOD, rcmr_period)
633 		| SSC_BF(RCMR_CKI, SSC_CKI_RISING);
634 
635 	tcmr |=   SSC_BF(TCMR_PERIOD, tcmr_period)
636 		| SSC_BF(TCMR_CKI, SSC_CKI_FALLING);
637 
638 	rfmr =    SSC_BF(RFMR_FSLEN_EXT, fslen_ext)
639 		| SSC_BF(RFMR_FSEDGE, SSC_FSEDGE_POSITIVE)
640 		| SSC_BF(RFMR_FSOS, fs_osync)
641 		| SSC_BF(RFMR_FSLEN, fslen)
642 		| SSC_BF(RFMR_DATNB, (channels - 1))
643 		| SSC_BIT(RFMR_MSBF)
644 		| SSC_BF(RFMR_LOOP, 0)
645 		| SSC_BF(RFMR_DATLEN, (bits - 1));
646 
647 	tfmr =    SSC_BF(TFMR_FSLEN_EXT, fslen_ext)
648 		| SSC_BF(TFMR_FSEDGE, SSC_FSEDGE_POSITIVE)
649 		| SSC_BF(TFMR_FSDEN, 0)
650 		| SSC_BF(TFMR_FSOS, fs_osync)
651 		| SSC_BF(TFMR_FSLEN, fslen)
652 		| SSC_BF(TFMR_DATNB, (channels - 1))
653 		| SSC_BIT(TFMR_MSBF)
654 		| SSC_BF(TFMR_DATDEF, 0)
655 		| SSC_BF(TFMR_DATLEN, (bits - 1));
656 
657 	if (fslen_ext && !ssc->pdata->has_fslen_ext) {
658 		dev_err(dai->dev, "sample size %d is too large for SSC device\n",
659 			bits);
660 		return -EINVAL;
661 	}
662 
663 	pr_debug("atmel_ssc_hw_params: "
664 			"RCMR=%08x RFMR=%08x TCMR=%08x TFMR=%08x\n",
665 			rcmr, rfmr, tcmr, tfmr);
666 
667 	if (!ssc_p->initialized) {
668 		if (!ssc_p->ssc->pdata->use_dma) {
669 			ssc_writel(ssc_p->ssc->regs, PDC_RPR, 0);
670 			ssc_writel(ssc_p->ssc->regs, PDC_RCR, 0);
671 			ssc_writel(ssc_p->ssc->regs, PDC_RNPR, 0);
672 			ssc_writel(ssc_p->ssc->regs, PDC_RNCR, 0);
673 
674 			ssc_writel(ssc_p->ssc->regs, PDC_TPR, 0);
675 			ssc_writel(ssc_p->ssc->regs, PDC_TCR, 0);
676 			ssc_writel(ssc_p->ssc->regs, PDC_TNPR, 0);
677 			ssc_writel(ssc_p->ssc->regs, PDC_TNCR, 0);
678 		}
679 
680 		ret = request_irq(ssc_p->ssc->irq, atmel_ssc_interrupt, 0,
681 				ssc_p->name, ssc_p);
682 		if (ret < 0) {
683 			printk(KERN_WARNING
684 					"atmel_ssc_dai: request_irq failure\n");
685 			pr_debug("Atmel_ssc_dai: Stopping clock\n");
686 			clk_disable(ssc_p->ssc->clk);
687 			return ret;
688 		}
689 
690 		ssc_p->initialized = 1;
691 	}
692 
693 	/* set SSC clock mode register */
694 	ssc_writel(ssc_p->ssc->regs, CMR, cmr_div);
695 
696 	/* set receive clock mode and format */
697 	ssc_writel(ssc_p->ssc->regs, RCMR, rcmr);
698 	ssc_writel(ssc_p->ssc->regs, RFMR, rfmr);
699 
700 	/* set transmit clock mode and format */
701 	ssc_writel(ssc_p->ssc->regs, TCMR, tcmr);
702 	ssc_writel(ssc_p->ssc->regs, TFMR, tfmr);
703 
704 	pr_debug("atmel_ssc_dai,hw_params: SSC initialized\n");
705 	return 0;
706 }
707 
708 
709 static int atmel_ssc_prepare(struct snd_pcm_substream *substream,
710 			     struct snd_soc_dai *dai)
711 {
712 	struct platform_device *pdev = to_platform_device(dai->dev);
713 	struct atmel_ssc_info *ssc_p = &ssc_info[pdev->id];
714 	struct atmel_pcm_dma_params *dma_params;
715 	int dir;
716 
717 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
718 		dir = 0;
719 	else
720 		dir = 1;
721 
722 	dma_params = ssc_p->dma_params[dir];
723 
724 	ssc_writel(ssc_p->ssc->regs, CR, dma_params->mask->ssc_disable);
725 	ssc_writel(ssc_p->ssc->regs, IDR, dma_params->mask->ssc_error);
726 
727 	pr_debug("%s enabled SSC_SR=0x%08x\n",
728 			dir ? "receive" : "transmit",
729 			ssc_readl(ssc_p->ssc->regs, SR));
730 	return 0;
731 }
732 
733 static int atmel_ssc_trigger(struct snd_pcm_substream *substream,
734 			     int cmd, struct snd_soc_dai *dai)
735 {
736 	struct platform_device *pdev = to_platform_device(dai->dev);
737 	struct atmel_ssc_info *ssc_p = &ssc_info[pdev->id];
738 	struct atmel_pcm_dma_params *dma_params;
739 	int dir;
740 
741 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
742 		dir = 0;
743 	else
744 		dir = 1;
745 
746 	dma_params = ssc_p->dma_params[dir];
747 
748 	switch (cmd) {
749 	case SNDRV_PCM_TRIGGER_START:
750 	case SNDRV_PCM_TRIGGER_RESUME:
751 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
752 		ssc_writel(ssc_p->ssc->regs, CR, dma_params->mask->ssc_enable);
753 		break;
754 	default:
755 		ssc_writel(ssc_p->ssc->regs, CR, dma_params->mask->ssc_disable);
756 		break;
757 	}
758 
759 	return 0;
760 }
761 
762 #ifdef CONFIG_PM
763 static int atmel_ssc_suspend(struct snd_soc_component *component)
764 {
765 	struct atmel_ssc_info *ssc_p;
766 	struct platform_device *pdev = to_platform_device(component->dev);
767 
768 	if (!snd_soc_component_active(component))
769 		return 0;
770 
771 	ssc_p = &ssc_info[pdev->id];
772 
773 	/* Save the status register before disabling transmit and receive */
774 	ssc_p->ssc_state.ssc_sr = ssc_readl(ssc_p->ssc->regs, SR);
775 	ssc_writel(ssc_p->ssc->regs, CR, SSC_BIT(CR_TXDIS) | SSC_BIT(CR_RXDIS));
776 
777 	/* Save the current interrupt mask, then disable unmasked interrupts */
778 	ssc_p->ssc_state.ssc_imr = ssc_readl(ssc_p->ssc->regs, IMR);
779 	ssc_writel(ssc_p->ssc->regs, IDR, ssc_p->ssc_state.ssc_imr);
780 
781 	ssc_p->ssc_state.ssc_cmr = ssc_readl(ssc_p->ssc->regs, CMR);
782 	ssc_p->ssc_state.ssc_rcmr = ssc_readl(ssc_p->ssc->regs, RCMR);
783 	ssc_p->ssc_state.ssc_rfmr = ssc_readl(ssc_p->ssc->regs, RFMR);
784 	ssc_p->ssc_state.ssc_tcmr = ssc_readl(ssc_p->ssc->regs, TCMR);
785 	ssc_p->ssc_state.ssc_tfmr = ssc_readl(ssc_p->ssc->regs, TFMR);
786 
787 	return 0;
788 }
789 
790 static int atmel_ssc_resume(struct snd_soc_component *component)
791 {
792 	struct atmel_ssc_info *ssc_p;
793 	struct platform_device *pdev = to_platform_device(component->dev);
794 	u32 cr;
795 
796 	if (!snd_soc_component_active(component))
797 		return 0;
798 
799 	ssc_p = &ssc_info[pdev->id];
800 
801 	/* restore SSC register settings */
802 	ssc_writel(ssc_p->ssc->regs, TFMR, ssc_p->ssc_state.ssc_tfmr);
803 	ssc_writel(ssc_p->ssc->regs, TCMR, ssc_p->ssc_state.ssc_tcmr);
804 	ssc_writel(ssc_p->ssc->regs, RFMR, ssc_p->ssc_state.ssc_rfmr);
805 	ssc_writel(ssc_p->ssc->regs, RCMR, ssc_p->ssc_state.ssc_rcmr);
806 	ssc_writel(ssc_p->ssc->regs, CMR, ssc_p->ssc_state.ssc_cmr);
807 
808 	/* re-enable interrupts */
809 	ssc_writel(ssc_p->ssc->regs, IER, ssc_p->ssc_state.ssc_imr);
810 
811 	/* Re-enable receive and transmit as appropriate */
812 	cr = 0;
813 	cr |=
814 	    (ssc_p->ssc_state.ssc_sr & SSC_BIT(SR_RXEN)) ? SSC_BIT(CR_RXEN) : 0;
815 	cr |=
816 	    (ssc_p->ssc_state.ssc_sr & SSC_BIT(SR_TXEN)) ? SSC_BIT(CR_TXEN) : 0;
817 	ssc_writel(ssc_p->ssc->regs, CR, cr);
818 
819 	return 0;
820 }
821 #else /* CONFIG_PM */
822 #  define atmel_ssc_suspend	NULL
823 #  define atmel_ssc_resume	NULL
824 #endif /* CONFIG_PM */
825 
826 #define ATMEL_SSC_FORMATS (SNDRV_PCM_FMTBIT_S8     | SNDRV_PCM_FMTBIT_S16_LE |\
827 			  SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S32_LE)
828 
829 static const struct snd_soc_dai_ops atmel_ssc_dai_ops = {
830 	.startup	= atmel_ssc_startup,
831 	.shutdown	= atmel_ssc_shutdown,
832 	.prepare	= atmel_ssc_prepare,
833 	.trigger	= atmel_ssc_trigger,
834 	.hw_params	= atmel_ssc_hw_params,
835 	.set_fmt	= atmel_ssc_set_dai_fmt,
836 	.set_clkdiv	= atmel_ssc_set_dai_clkdiv,
837 };
838 
839 static struct snd_soc_dai_driver atmel_ssc_dai = {
840 		.playback = {
841 			.channels_min = 1,
842 			.channels_max = 2,
843 			.rates = SNDRV_PCM_RATE_CONTINUOUS,
844 			.rate_min = 8000,
845 			.rate_max = 384000,
846 			.formats = ATMEL_SSC_FORMATS,},
847 		.capture = {
848 			.channels_min = 1,
849 			.channels_max = 2,
850 			.rates = SNDRV_PCM_RATE_CONTINUOUS,
851 			.rate_min = 8000,
852 			.rate_max = 384000,
853 			.formats = ATMEL_SSC_FORMATS,},
854 		.ops = &atmel_ssc_dai_ops,
855 };
856 
857 static const struct snd_soc_component_driver atmel_ssc_component = {
858 	.name		= "atmel-ssc",
859 	.suspend	= atmel_ssc_suspend,
860 	.resume		= atmel_ssc_resume,
861 };
862 
863 static int asoc_ssc_init(struct device *dev)
864 {
865 	struct ssc_device *ssc = dev_get_drvdata(dev);
866 	int ret;
867 
868 	ret = devm_snd_soc_register_component(dev, &atmel_ssc_component,
869 					 &atmel_ssc_dai, 1);
870 	if (ret) {
871 		dev_err(dev, "Could not register DAI: %d\n", ret);
872 		return ret;
873 	}
874 
875 	if (ssc->pdata->use_dma)
876 		ret = atmel_pcm_dma_platform_register(dev);
877 	else
878 		ret = atmel_pcm_pdc_platform_register(dev);
879 
880 	if (ret) {
881 		dev_err(dev, "Could not register PCM: %d\n", ret);
882 		return ret;
883 	}
884 
885 	return 0;
886 }
887 
888 /**
889  * atmel_ssc_set_audio - Allocate the specified SSC for audio use.
890  * @ssc_id: SSD ID in [0, NUM_SSC_DEVICES[
891  */
892 int atmel_ssc_set_audio(int ssc_id)
893 {
894 	struct ssc_device *ssc;
895 	int ret;
896 
897 	/* If we can grab the SSC briefly to parent the DAI device off it */
898 	ssc = ssc_request(ssc_id);
899 	if (IS_ERR(ssc)) {
900 		pr_err("Unable to parent ASoC SSC DAI on SSC: %ld\n",
901 			PTR_ERR(ssc));
902 		return PTR_ERR(ssc);
903 	} else {
904 		ssc_info[ssc_id].ssc = ssc;
905 	}
906 
907 	ret = asoc_ssc_init(&ssc->pdev->dev);
908 
909 	return ret;
910 }
911 EXPORT_SYMBOL_GPL(atmel_ssc_set_audio);
912 
913 void atmel_ssc_put_audio(int ssc_id)
914 {
915 	struct ssc_device *ssc = ssc_info[ssc_id].ssc;
916 
917 	ssc_free(ssc);
918 }
919 EXPORT_SYMBOL_GPL(atmel_ssc_put_audio);
920 
921 /* Module information */
922 MODULE_AUTHOR("Sedji Gaouaou, sedji.gaouaou@atmel.com, www.atmel.com");
923 MODULE_DESCRIPTION("ATMEL SSC ASoC Interface");
924 MODULE_LICENSE("GPL");
925