xref: /openbmc/linux/sound/soc/atmel/atmel_ssc_dai.c (revision 7419995a)
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 	ret = clk_enable(ssc_p->ssc->clk);
284 	if (ret)
285 		return ret;
286 
287 	ssc_p->mck_rate = clk_get_rate(ssc_p->ssc->clk);
288 
289 	/* Reset the SSC unless initialized to keep it in a clean state */
290 	if (!ssc_p->initialized)
291 		ssc_writel(ssc_p->ssc->regs, CR, SSC_BIT(CR_SWRST));
292 
293 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
294 		dir = 0;
295 		dir_mask = SSC_DIR_MASK_PLAYBACK;
296 	} else {
297 		dir = 1;
298 		dir_mask = SSC_DIR_MASK_CAPTURE;
299 	}
300 
301 	ret = snd_pcm_hw_rule_add(substream->runtime, 0,
302 				  SNDRV_PCM_HW_PARAM_RATE,
303 				  atmel_ssc_hw_rule_rate,
304 				  ssc_p,
305 				  SNDRV_PCM_HW_PARAM_FRAME_BITS,
306 				  SNDRV_PCM_HW_PARAM_CHANNELS, -1);
307 	if (ret < 0) {
308 		dev_err(dai->dev, "Failed to specify rate rule: %d\n", ret);
309 		return ret;
310 	}
311 
312 	dma_params = &ssc_dma_params[pdev->id][dir];
313 	dma_params->ssc = ssc_p->ssc;
314 	dma_params->substream = substream;
315 
316 	ssc_p->dma_params[dir] = dma_params;
317 
318 	snd_soc_dai_set_dma_data(dai, substream, dma_params);
319 
320 	if (ssc_p->dir_mask & dir_mask)
321 		return -EBUSY;
322 
323 	ssc_p->dir_mask |= dir_mask;
324 
325 	return 0;
326 }
327 
328 /*
329  * Shutdown.  Clear DMA parameters and shutdown the SSC if there
330  * are no other substreams open.
331  */
332 static void atmel_ssc_shutdown(struct snd_pcm_substream *substream,
333 			       struct snd_soc_dai *dai)
334 {
335 	struct platform_device *pdev = to_platform_device(dai->dev);
336 	struct atmel_ssc_info *ssc_p = &ssc_info[pdev->id];
337 	struct atmel_pcm_dma_params *dma_params;
338 	int dir, dir_mask;
339 
340 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
341 		dir = 0;
342 	else
343 		dir = 1;
344 
345 	dma_params = ssc_p->dma_params[dir];
346 
347 	if (dma_params != NULL) {
348 		dma_params->ssc = NULL;
349 		dma_params->substream = NULL;
350 		ssc_p->dma_params[dir] = NULL;
351 	}
352 
353 	dir_mask = 1 << dir;
354 
355 	ssc_p->dir_mask &= ~dir_mask;
356 	if (!ssc_p->dir_mask) {
357 		if (ssc_p->initialized) {
358 			free_irq(ssc_p->ssc->irq, ssc_p);
359 			ssc_p->initialized = 0;
360 		}
361 
362 		/* Reset the SSC */
363 		ssc_writel(ssc_p->ssc->regs, CR, SSC_BIT(CR_SWRST));
364 		/* Clear the SSC dividers */
365 		ssc_p->cmr_div = ssc_p->tcmr_period = ssc_p->rcmr_period = 0;
366 		ssc_p->forced_divider = 0;
367 	}
368 
369 	/* Shutdown the SSC clock. */
370 	pr_debug("atmel_ssc_dai: Stopping clock\n");
371 	clk_disable(ssc_p->ssc->clk);
372 }
373 
374 
375 /*
376  * Record the DAI format for use in hw_params().
377  */
378 static int atmel_ssc_set_dai_fmt(struct snd_soc_dai *cpu_dai,
379 		unsigned int fmt)
380 {
381 	struct platform_device *pdev = to_platform_device(cpu_dai->dev);
382 	struct atmel_ssc_info *ssc_p = &ssc_info[pdev->id];
383 
384 	ssc_p->daifmt = fmt;
385 	return 0;
386 }
387 
388 /*
389  * Record SSC clock dividers for use in hw_params().
390  */
391 static int atmel_ssc_set_dai_clkdiv(struct snd_soc_dai *cpu_dai,
392 	int div_id, int div)
393 {
394 	struct platform_device *pdev = to_platform_device(cpu_dai->dev);
395 	struct atmel_ssc_info *ssc_p = &ssc_info[pdev->id];
396 
397 	switch (div_id) {
398 	case ATMEL_SSC_CMR_DIV:
399 		/*
400 		 * The same master clock divider is used for both
401 		 * transmit and receive, so if a value has already
402 		 * been set, it must match this value.
403 		 */
404 		if (ssc_p->dir_mask !=
405 			(SSC_DIR_MASK_PLAYBACK | SSC_DIR_MASK_CAPTURE))
406 			ssc_p->cmr_div = div;
407 		else if (ssc_p->cmr_div == 0)
408 			ssc_p->cmr_div = div;
409 		else
410 			if (div != ssc_p->cmr_div)
411 				return -EBUSY;
412 		ssc_p->forced_divider |= BIT(ATMEL_SSC_CMR_DIV);
413 		break;
414 
415 	case ATMEL_SSC_TCMR_PERIOD:
416 		ssc_p->tcmr_period = div;
417 		ssc_p->forced_divider |= BIT(ATMEL_SSC_TCMR_PERIOD);
418 		break;
419 
420 	case ATMEL_SSC_RCMR_PERIOD:
421 		ssc_p->rcmr_period = div;
422 		ssc_p->forced_divider |= BIT(ATMEL_SSC_RCMR_PERIOD);
423 		break;
424 
425 	default:
426 		return -EINVAL;
427 	}
428 
429 	return 0;
430 }
431 
432 /* Is the cpu-dai master of the frame clock? */
433 static int atmel_ssc_cfs(struct atmel_ssc_info *ssc_p)
434 {
435 	switch (ssc_p->daifmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK) {
436 	case SND_SOC_DAIFMT_CBP_CFC:
437 	case SND_SOC_DAIFMT_CBC_CFC:
438 		return 1;
439 	}
440 	return 0;
441 }
442 
443 /* Is the cpu-dai master of the bit clock? */
444 static int atmel_ssc_cbs(struct atmel_ssc_info *ssc_p)
445 {
446 	switch (ssc_p->daifmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK) {
447 	case SND_SOC_DAIFMT_CBC_CFP:
448 	case SND_SOC_DAIFMT_CBC_CFC:
449 		return 1;
450 	}
451 	return 0;
452 }
453 
454 /*
455  * Configure the SSC.
456  */
457 static int atmel_ssc_hw_params(struct snd_pcm_substream *substream,
458 	struct snd_pcm_hw_params *params,
459 	struct snd_soc_dai *dai)
460 {
461 	struct platform_device *pdev = to_platform_device(dai->dev);
462 	int id = pdev->id;
463 	struct atmel_ssc_info *ssc_p = &ssc_info[id];
464 	struct ssc_device *ssc = ssc_p->ssc;
465 	struct atmel_pcm_dma_params *dma_params;
466 	int dir, channels, bits;
467 	u32 tfmr, rfmr, tcmr, rcmr;
468 	int ret;
469 	int fslen, fslen_ext, fs_osync, fs_edge;
470 	u32 cmr_div;
471 	u32 tcmr_period;
472 	u32 rcmr_period;
473 
474 	/*
475 	 * Currently, there is only one set of dma params for
476 	 * each direction.  If more are added, this code will
477 	 * have to be changed to select the proper set.
478 	 */
479 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
480 		dir = 0;
481 	else
482 		dir = 1;
483 
484 	/*
485 	 * If the cpu dai should provide BCLK, but noone has provided the
486 	 * divider needed for that to work, fall back to something sensible.
487 	 */
488 	cmr_div = ssc_p->cmr_div;
489 	if (!(ssc_p->forced_divider & BIT(ATMEL_SSC_CMR_DIV)) &&
490 	    atmel_ssc_cbs(ssc_p)) {
491 		int bclk_rate = snd_soc_params_to_bclk(params);
492 
493 		if (bclk_rate < 0) {
494 			dev_err(dai->dev, "unable to calculate cmr_div: %d\n",
495 				bclk_rate);
496 			return bclk_rate;
497 		}
498 
499 		cmr_div = DIV_ROUND_CLOSEST(ssc_p->mck_rate, 2 * bclk_rate);
500 	}
501 
502 	/*
503 	 * If the cpu dai should provide LRCLK, but noone has provided the
504 	 * dividers needed for that to work, fall back to something sensible.
505 	 */
506 	tcmr_period = ssc_p->tcmr_period;
507 	rcmr_period = ssc_p->rcmr_period;
508 	if (atmel_ssc_cfs(ssc_p)) {
509 		int frame_size = snd_soc_params_to_frame_size(params);
510 
511 		if (frame_size < 0) {
512 			dev_err(dai->dev,
513 				"unable to calculate tx/rx cmr_period: %d\n",
514 				frame_size);
515 			return frame_size;
516 		}
517 
518 		if (!(ssc_p->forced_divider & BIT(ATMEL_SSC_TCMR_PERIOD)))
519 			tcmr_period = frame_size / 2 - 1;
520 		if (!(ssc_p->forced_divider & BIT(ATMEL_SSC_RCMR_PERIOD)))
521 			rcmr_period = frame_size / 2 - 1;
522 	}
523 
524 	dma_params = ssc_p->dma_params[dir];
525 
526 	channels = params_channels(params);
527 
528 	/*
529 	 * Determine sample size in bits and the PDC increment.
530 	 */
531 	switch (params_format(params)) {
532 	case SNDRV_PCM_FORMAT_S8:
533 		bits = 8;
534 		dma_params->pdc_xfer_size = 1;
535 		break;
536 	case SNDRV_PCM_FORMAT_S16_LE:
537 		bits = 16;
538 		dma_params->pdc_xfer_size = 2;
539 		break;
540 	case SNDRV_PCM_FORMAT_S24_LE:
541 		bits = 24;
542 		dma_params->pdc_xfer_size = 4;
543 		break;
544 	case SNDRV_PCM_FORMAT_S32_LE:
545 		bits = 32;
546 		dma_params->pdc_xfer_size = 4;
547 		break;
548 	default:
549 		printk(KERN_WARNING "atmel_ssc_dai: unsupported PCM format");
550 		return -EINVAL;
551 	}
552 
553 	/*
554 	 * Compute SSC register settings.
555 	 */
556 
557 	fslen_ext = (bits - 1) / 16;
558 	fslen = (bits - 1) % 16;
559 
560 	switch (ssc_p->daifmt & SND_SOC_DAIFMT_FORMAT_MASK) {
561 
562 	case SND_SOC_DAIFMT_LEFT_J:
563 		fs_osync = SSC_FSOS_POSITIVE;
564 		fs_edge = SSC_START_RISING_RF;
565 
566 		rcmr =	  SSC_BF(RCMR_STTDLY, 0);
567 		tcmr =	  SSC_BF(TCMR_STTDLY, 0);
568 
569 		break;
570 
571 	case SND_SOC_DAIFMT_I2S:
572 		fs_osync = SSC_FSOS_NEGATIVE;
573 		fs_edge = SSC_START_FALLING_RF;
574 
575 		rcmr =	  SSC_BF(RCMR_STTDLY, 1);
576 		tcmr =	  SSC_BF(TCMR_STTDLY, 1);
577 
578 		break;
579 
580 	case SND_SOC_DAIFMT_DSP_A:
581 		/*
582 		 * DSP/PCM Mode A format
583 		 *
584 		 * Data is transferred on first BCLK after LRC pulse rising
585 		 * edge.If stereo, the right channel data is contiguous with
586 		 * the left channel data.
587 		 */
588 		fs_osync = SSC_FSOS_POSITIVE;
589 		fs_edge = SSC_START_RISING_RF;
590 		fslen = fslen_ext = 0;
591 
592 		rcmr =	  SSC_BF(RCMR_STTDLY, 1);
593 		tcmr =	  SSC_BF(TCMR_STTDLY, 1);
594 
595 		break;
596 
597 	default:
598 		printk(KERN_WARNING "atmel_ssc_dai: unsupported DAI format 0x%x\n",
599 			ssc_p->daifmt);
600 		return -EINVAL;
601 	}
602 
603 	if (!atmel_ssc_cfs(ssc_p)) {
604 		fslen = fslen_ext = 0;
605 		rcmr_period = tcmr_period = 0;
606 		fs_osync = SSC_FSOS_NONE;
607 	}
608 
609 	rcmr |=	  SSC_BF(RCMR_START, fs_edge);
610 	tcmr |=	  SSC_BF(TCMR_START, fs_edge);
611 
612 	if (atmel_ssc_cbs(ssc_p)) {
613 		/*
614 		 * SSC provides BCLK
615 		 *
616 		 * The SSC transmit and receive clocks are generated from the
617 		 * MCK divider, and the BCLK signal is output
618 		 * on the SSC TK line.
619 		 */
620 		rcmr |=	  SSC_BF(RCMR_CKS, SSC_CKS_DIV)
621 			| SSC_BF(RCMR_CKO, SSC_CKO_NONE);
622 
623 		tcmr |=	  SSC_BF(TCMR_CKS, SSC_CKS_DIV)
624 			| SSC_BF(TCMR_CKO, SSC_CKO_CONTINUOUS);
625 	} else {
626 		rcmr |=	  SSC_BF(RCMR_CKS, ssc->clk_from_rk_pin ?
627 					SSC_CKS_PIN : SSC_CKS_CLOCK)
628 			| SSC_BF(RCMR_CKO, SSC_CKO_NONE);
629 
630 		tcmr |=	  SSC_BF(TCMR_CKS, ssc->clk_from_rk_pin ?
631 					SSC_CKS_CLOCK : SSC_CKS_PIN)
632 			| SSC_BF(TCMR_CKO, SSC_CKO_NONE);
633 	}
634 
635 	rcmr |=	  SSC_BF(RCMR_PERIOD, rcmr_period)
636 		| SSC_BF(RCMR_CKI, SSC_CKI_RISING);
637 
638 	tcmr |=   SSC_BF(TCMR_PERIOD, tcmr_period)
639 		| SSC_BF(TCMR_CKI, SSC_CKI_FALLING);
640 
641 	rfmr =    SSC_BF(RFMR_FSLEN_EXT, fslen_ext)
642 		| SSC_BF(RFMR_FSEDGE, SSC_FSEDGE_POSITIVE)
643 		| SSC_BF(RFMR_FSOS, fs_osync)
644 		| SSC_BF(RFMR_FSLEN, fslen)
645 		| SSC_BF(RFMR_DATNB, (channels - 1))
646 		| SSC_BIT(RFMR_MSBF)
647 		| SSC_BF(RFMR_LOOP, 0)
648 		| SSC_BF(RFMR_DATLEN, (bits - 1));
649 
650 	tfmr =    SSC_BF(TFMR_FSLEN_EXT, fslen_ext)
651 		| SSC_BF(TFMR_FSEDGE, SSC_FSEDGE_POSITIVE)
652 		| SSC_BF(TFMR_FSDEN, 0)
653 		| SSC_BF(TFMR_FSOS, fs_osync)
654 		| SSC_BF(TFMR_FSLEN, fslen)
655 		| SSC_BF(TFMR_DATNB, (channels - 1))
656 		| SSC_BIT(TFMR_MSBF)
657 		| SSC_BF(TFMR_DATDEF, 0)
658 		| SSC_BF(TFMR_DATLEN, (bits - 1));
659 
660 	if (fslen_ext && !ssc->pdata->has_fslen_ext) {
661 		dev_err(dai->dev, "sample size %d is too large for SSC device\n",
662 			bits);
663 		return -EINVAL;
664 	}
665 
666 	pr_debug("atmel_ssc_hw_params: "
667 			"RCMR=%08x RFMR=%08x TCMR=%08x TFMR=%08x\n",
668 			rcmr, rfmr, tcmr, tfmr);
669 
670 	if (!ssc_p->initialized) {
671 		if (!ssc_p->ssc->pdata->use_dma) {
672 			ssc_writel(ssc_p->ssc->regs, PDC_RPR, 0);
673 			ssc_writel(ssc_p->ssc->regs, PDC_RCR, 0);
674 			ssc_writel(ssc_p->ssc->regs, PDC_RNPR, 0);
675 			ssc_writel(ssc_p->ssc->regs, PDC_RNCR, 0);
676 
677 			ssc_writel(ssc_p->ssc->regs, PDC_TPR, 0);
678 			ssc_writel(ssc_p->ssc->regs, PDC_TCR, 0);
679 			ssc_writel(ssc_p->ssc->regs, PDC_TNPR, 0);
680 			ssc_writel(ssc_p->ssc->regs, PDC_TNCR, 0);
681 		}
682 
683 		ret = request_irq(ssc_p->ssc->irq, atmel_ssc_interrupt, 0,
684 				ssc_p->name, ssc_p);
685 		if (ret < 0) {
686 			printk(KERN_WARNING
687 					"atmel_ssc_dai: request_irq failure\n");
688 			pr_debug("Atmel_ssc_dai: Stopping clock\n");
689 			clk_disable(ssc_p->ssc->clk);
690 			return ret;
691 		}
692 
693 		ssc_p->initialized = 1;
694 	}
695 
696 	/* set SSC clock mode register */
697 	ssc_writel(ssc_p->ssc->regs, CMR, cmr_div);
698 
699 	/* set receive clock mode and format */
700 	ssc_writel(ssc_p->ssc->regs, RCMR, rcmr);
701 	ssc_writel(ssc_p->ssc->regs, RFMR, rfmr);
702 
703 	/* set transmit clock mode and format */
704 	ssc_writel(ssc_p->ssc->regs, TCMR, tcmr);
705 	ssc_writel(ssc_p->ssc->regs, TFMR, tfmr);
706 
707 	pr_debug("atmel_ssc_dai,hw_params: SSC initialized\n");
708 	return 0;
709 }
710 
711 
712 static int atmel_ssc_prepare(struct snd_pcm_substream *substream,
713 			     struct snd_soc_dai *dai)
714 {
715 	struct platform_device *pdev = to_platform_device(dai->dev);
716 	struct atmel_ssc_info *ssc_p = &ssc_info[pdev->id];
717 	struct atmel_pcm_dma_params *dma_params;
718 	int dir;
719 
720 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
721 		dir = 0;
722 	else
723 		dir = 1;
724 
725 	dma_params = ssc_p->dma_params[dir];
726 
727 	ssc_writel(ssc_p->ssc->regs, CR, dma_params->mask->ssc_disable);
728 	ssc_writel(ssc_p->ssc->regs, IDR, dma_params->mask->ssc_error);
729 
730 	pr_debug("%s enabled SSC_SR=0x%08x\n",
731 			dir ? "receive" : "transmit",
732 			ssc_readl(ssc_p->ssc->regs, SR));
733 	return 0;
734 }
735 
736 static int atmel_ssc_trigger(struct snd_pcm_substream *substream,
737 			     int cmd, struct snd_soc_dai *dai)
738 {
739 	struct platform_device *pdev = to_platform_device(dai->dev);
740 	struct atmel_ssc_info *ssc_p = &ssc_info[pdev->id];
741 	struct atmel_pcm_dma_params *dma_params;
742 	int dir;
743 
744 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
745 		dir = 0;
746 	else
747 		dir = 1;
748 
749 	dma_params = ssc_p->dma_params[dir];
750 
751 	switch (cmd) {
752 	case SNDRV_PCM_TRIGGER_START:
753 	case SNDRV_PCM_TRIGGER_RESUME:
754 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
755 		ssc_writel(ssc_p->ssc->regs, CR, dma_params->mask->ssc_enable);
756 		break;
757 	default:
758 		ssc_writel(ssc_p->ssc->regs, CR, dma_params->mask->ssc_disable);
759 		break;
760 	}
761 
762 	return 0;
763 }
764 
765 #ifdef CONFIG_PM
766 static int atmel_ssc_suspend(struct snd_soc_component *component)
767 {
768 	struct atmel_ssc_info *ssc_p;
769 	struct platform_device *pdev = to_platform_device(component->dev);
770 
771 	if (!snd_soc_component_active(component))
772 		return 0;
773 
774 	ssc_p = &ssc_info[pdev->id];
775 
776 	/* Save the status register before disabling transmit and receive */
777 	ssc_p->ssc_state.ssc_sr = ssc_readl(ssc_p->ssc->regs, SR);
778 	ssc_writel(ssc_p->ssc->regs, CR, SSC_BIT(CR_TXDIS) | SSC_BIT(CR_RXDIS));
779 
780 	/* Save the current interrupt mask, then disable unmasked interrupts */
781 	ssc_p->ssc_state.ssc_imr = ssc_readl(ssc_p->ssc->regs, IMR);
782 	ssc_writel(ssc_p->ssc->regs, IDR, ssc_p->ssc_state.ssc_imr);
783 
784 	ssc_p->ssc_state.ssc_cmr = ssc_readl(ssc_p->ssc->regs, CMR);
785 	ssc_p->ssc_state.ssc_rcmr = ssc_readl(ssc_p->ssc->regs, RCMR);
786 	ssc_p->ssc_state.ssc_rfmr = ssc_readl(ssc_p->ssc->regs, RFMR);
787 	ssc_p->ssc_state.ssc_tcmr = ssc_readl(ssc_p->ssc->regs, TCMR);
788 	ssc_p->ssc_state.ssc_tfmr = ssc_readl(ssc_p->ssc->regs, TFMR);
789 
790 	return 0;
791 }
792 
793 static int atmel_ssc_resume(struct snd_soc_component *component)
794 {
795 	struct atmel_ssc_info *ssc_p;
796 	struct platform_device *pdev = to_platform_device(component->dev);
797 	u32 cr;
798 
799 	if (!snd_soc_component_active(component))
800 		return 0;
801 
802 	ssc_p = &ssc_info[pdev->id];
803 
804 	/* restore SSC register settings */
805 	ssc_writel(ssc_p->ssc->regs, TFMR, ssc_p->ssc_state.ssc_tfmr);
806 	ssc_writel(ssc_p->ssc->regs, TCMR, ssc_p->ssc_state.ssc_tcmr);
807 	ssc_writel(ssc_p->ssc->regs, RFMR, ssc_p->ssc_state.ssc_rfmr);
808 	ssc_writel(ssc_p->ssc->regs, RCMR, ssc_p->ssc_state.ssc_rcmr);
809 	ssc_writel(ssc_p->ssc->regs, CMR, ssc_p->ssc_state.ssc_cmr);
810 
811 	/* re-enable interrupts */
812 	ssc_writel(ssc_p->ssc->regs, IER, ssc_p->ssc_state.ssc_imr);
813 
814 	/* Re-enable receive and transmit as appropriate */
815 	cr = 0;
816 	cr |=
817 	    (ssc_p->ssc_state.ssc_sr & SSC_BIT(SR_RXEN)) ? SSC_BIT(CR_RXEN) : 0;
818 	cr |=
819 	    (ssc_p->ssc_state.ssc_sr & SSC_BIT(SR_TXEN)) ? SSC_BIT(CR_TXEN) : 0;
820 	ssc_writel(ssc_p->ssc->regs, CR, cr);
821 
822 	return 0;
823 }
824 #else /* CONFIG_PM */
825 #  define atmel_ssc_suspend	NULL
826 #  define atmel_ssc_resume	NULL
827 #endif /* CONFIG_PM */
828 
829 #define ATMEL_SSC_FORMATS (SNDRV_PCM_FMTBIT_S8     | SNDRV_PCM_FMTBIT_S16_LE |\
830 			  SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S32_LE)
831 
832 static const struct snd_soc_dai_ops atmel_ssc_dai_ops = {
833 	.startup	= atmel_ssc_startup,
834 	.shutdown	= atmel_ssc_shutdown,
835 	.prepare	= atmel_ssc_prepare,
836 	.trigger	= atmel_ssc_trigger,
837 	.hw_params	= atmel_ssc_hw_params,
838 	.set_fmt	= atmel_ssc_set_dai_fmt,
839 	.set_clkdiv	= atmel_ssc_set_dai_clkdiv,
840 };
841 
842 static struct snd_soc_dai_driver atmel_ssc_dai = {
843 		.playback = {
844 			.channels_min = 1,
845 			.channels_max = 2,
846 			.rates = SNDRV_PCM_RATE_CONTINUOUS,
847 			.rate_min = 8000,
848 			.rate_max = 384000,
849 			.formats = ATMEL_SSC_FORMATS,},
850 		.capture = {
851 			.channels_min = 1,
852 			.channels_max = 2,
853 			.rates = SNDRV_PCM_RATE_CONTINUOUS,
854 			.rate_min = 8000,
855 			.rate_max = 384000,
856 			.formats = ATMEL_SSC_FORMATS,},
857 		.ops = &atmel_ssc_dai_ops,
858 };
859 
860 static const struct snd_soc_component_driver atmel_ssc_component = {
861 	.name		= "atmel-ssc",
862 	.suspend	= atmel_ssc_suspend,
863 	.resume		= atmel_ssc_resume,
864 };
865 
866 static int asoc_ssc_init(struct device *dev)
867 {
868 	struct ssc_device *ssc = dev_get_drvdata(dev);
869 	int ret;
870 
871 	ret = devm_snd_soc_register_component(dev, &atmel_ssc_component,
872 					 &atmel_ssc_dai, 1);
873 	if (ret) {
874 		dev_err(dev, "Could not register DAI: %d\n", ret);
875 		return ret;
876 	}
877 
878 	if (ssc->pdata->use_dma)
879 		ret = atmel_pcm_dma_platform_register(dev);
880 	else
881 		ret = atmel_pcm_pdc_platform_register(dev);
882 
883 	if (ret) {
884 		dev_err(dev, "Could not register PCM: %d\n", ret);
885 		return ret;
886 	}
887 
888 	return 0;
889 }
890 
891 /**
892  * atmel_ssc_set_audio - Allocate the specified SSC for audio use.
893  * @ssc_id: SSD ID in [0, NUM_SSC_DEVICES[
894  */
895 int atmel_ssc_set_audio(int ssc_id)
896 {
897 	struct ssc_device *ssc;
898 	int ret;
899 
900 	/* If we can grab the SSC briefly to parent the DAI device off it */
901 	ssc = ssc_request(ssc_id);
902 	if (IS_ERR(ssc)) {
903 		pr_err("Unable to parent ASoC SSC DAI on SSC: %ld\n",
904 			PTR_ERR(ssc));
905 		return PTR_ERR(ssc);
906 	} else {
907 		ssc_info[ssc_id].ssc = ssc;
908 	}
909 
910 	ret = asoc_ssc_init(&ssc->pdev->dev);
911 
912 	return ret;
913 }
914 EXPORT_SYMBOL_GPL(atmel_ssc_set_audio);
915 
916 void atmel_ssc_put_audio(int ssc_id)
917 {
918 	struct ssc_device *ssc = ssc_info[ssc_id].ssc;
919 
920 	ssc_free(ssc);
921 }
922 EXPORT_SYMBOL_GPL(atmel_ssc_put_audio);
923 
924 /* Module information */
925 MODULE_AUTHOR("Sedji Gaouaou, sedji.gaouaou@atmel.com, www.atmel.com");
926 MODULE_DESCRIPTION("ATMEL SSC ASoC Interface");
927 MODULE_LICENSE("GPL");
928