xref: /linux/sound/soc/fsl/fsl_sai.c (revision af873fcecef567abf8a3468b06dd4e4aab46da6d)
1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // Freescale ALSA SoC Digital Audio Interface (SAI) driver.
4 //
5 // Copyright 2012-2015 Freescale Semiconductor, Inc.
6 
7 #include <linux/clk.h>
8 #include <linux/delay.h>
9 #include <linux/dmaengine.h>
10 #include <linux/module.h>
11 #include <linux/of_address.h>
12 #include <linux/pm_runtime.h>
13 #include <linux/regmap.h>
14 #include <linux/slab.h>
15 #include <linux/time.h>
16 #include <sound/core.h>
17 #include <sound/dmaengine_pcm.h>
18 #include <sound/pcm_params.h>
19 #include <linux/mfd/syscon.h>
20 #include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
21 
22 #include "fsl_sai.h"
23 #include "imx-pcm.h"
24 
25 #define FSL_SAI_FLAGS (FSL_SAI_CSR_SEIE |\
26 		       FSL_SAI_CSR_FEIE)
27 
28 static const unsigned int fsl_sai_rates[] = {
29 	8000, 11025, 12000, 16000, 22050,
30 	24000, 32000, 44100, 48000, 64000,
31 	88200, 96000, 176400, 192000
32 };
33 
34 static const struct snd_pcm_hw_constraint_list fsl_sai_rate_constraints = {
35 	.count = ARRAY_SIZE(fsl_sai_rates),
36 	.list = fsl_sai_rates,
37 };
38 
39 static irqreturn_t fsl_sai_isr(int irq, void *devid)
40 {
41 	struct fsl_sai *sai = (struct fsl_sai *)devid;
42 	struct device *dev = &sai->pdev->dev;
43 	u32 flags, xcsr, mask;
44 	bool irq_none = true;
45 
46 	/*
47 	 * Both IRQ status bits and IRQ mask bits are in the xCSR but
48 	 * different shifts. And we here create a mask only for those
49 	 * IRQs that we activated.
50 	 */
51 	mask = (FSL_SAI_FLAGS >> FSL_SAI_CSR_xIE_SHIFT) << FSL_SAI_CSR_xF_SHIFT;
52 
53 	/* Tx IRQ */
54 	regmap_read(sai->regmap, FSL_SAI_TCSR, &xcsr);
55 	flags = xcsr & mask;
56 
57 	if (flags)
58 		irq_none = false;
59 	else
60 		goto irq_rx;
61 
62 	if (flags & FSL_SAI_CSR_WSF)
63 		dev_dbg(dev, "isr: Start of Tx word detected\n");
64 
65 	if (flags & FSL_SAI_CSR_SEF)
66 		dev_dbg(dev, "isr: Tx Frame sync error detected\n");
67 
68 	if (flags & FSL_SAI_CSR_FEF) {
69 		dev_dbg(dev, "isr: Transmit underrun detected\n");
70 		/* FIFO reset for safety */
71 		xcsr |= FSL_SAI_CSR_FR;
72 	}
73 
74 	if (flags & FSL_SAI_CSR_FWF)
75 		dev_dbg(dev, "isr: Enabled transmit FIFO is empty\n");
76 
77 	if (flags & FSL_SAI_CSR_FRF)
78 		dev_dbg(dev, "isr: Transmit FIFO watermark has been reached\n");
79 
80 	flags &= FSL_SAI_CSR_xF_W_MASK;
81 	xcsr &= ~FSL_SAI_CSR_xF_MASK;
82 
83 	if (flags)
84 		regmap_write(sai->regmap, FSL_SAI_TCSR, flags | xcsr);
85 
86 irq_rx:
87 	/* Rx IRQ */
88 	regmap_read(sai->regmap, FSL_SAI_RCSR, &xcsr);
89 	flags = xcsr & mask;
90 
91 	if (flags)
92 		irq_none = false;
93 	else
94 		goto out;
95 
96 	if (flags & FSL_SAI_CSR_WSF)
97 		dev_dbg(dev, "isr: Start of Rx word detected\n");
98 
99 	if (flags & FSL_SAI_CSR_SEF)
100 		dev_dbg(dev, "isr: Rx Frame sync error detected\n");
101 
102 	if (flags & FSL_SAI_CSR_FEF) {
103 		dev_dbg(dev, "isr: Receive overflow detected\n");
104 		/* FIFO reset for safety */
105 		xcsr |= FSL_SAI_CSR_FR;
106 	}
107 
108 	if (flags & FSL_SAI_CSR_FWF)
109 		dev_dbg(dev, "isr: Enabled receive FIFO is full\n");
110 
111 	if (flags & FSL_SAI_CSR_FRF)
112 		dev_dbg(dev, "isr: Receive FIFO watermark has been reached\n");
113 
114 	flags &= FSL_SAI_CSR_xF_W_MASK;
115 	xcsr &= ~FSL_SAI_CSR_xF_MASK;
116 
117 	if (flags)
118 		regmap_write(sai->regmap, FSL_SAI_RCSR, flags | xcsr);
119 
120 out:
121 	if (irq_none)
122 		return IRQ_NONE;
123 	else
124 		return IRQ_HANDLED;
125 }
126 
127 static int fsl_sai_set_dai_tdm_slot(struct snd_soc_dai *cpu_dai, u32 tx_mask,
128 				u32 rx_mask, int slots, int slot_width)
129 {
130 	struct fsl_sai *sai = snd_soc_dai_get_drvdata(cpu_dai);
131 
132 	sai->slots = slots;
133 	sai->slot_width = slot_width;
134 
135 	return 0;
136 }
137 
138 static int fsl_sai_set_dai_sysclk_tr(struct snd_soc_dai *cpu_dai,
139 		int clk_id, unsigned int freq, int fsl_dir)
140 {
141 	struct fsl_sai *sai = snd_soc_dai_get_drvdata(cpu_dai);
142 	bool tx = fsl_dir == FSL_FMT_TRANSMITTER;
143 	u32 val_cr2 = 0;
144 
145 	switch (clk_id) {
146 	case FSL_SAI_CLK_BUS:
147 		val_cr2 |= FSL_SAI_CR2_MSEL_BUS;
148 		break;
149 	case FSL_SAI_CLK_MAST1:
150 		val_cr2 |= FSL_SAI_CR2_MSEL_MCLK1;
151 		break;
152 	case FSL_SAI_CLK_MAST2:
153 		val_cr2 |= FSL_SAI_CR2_MSEL_MCLK2;
154 		break;
155 	case FSL_SAI_CLK_MAST3:
156 		val_cr2 |= FSL_SAI_CR2_MSEL_MCLK3;
157 		break;
158 	default:
159 		return -EINVAL;
160 	}
161 
162 	regmap_update_bits(sai->regmap, FSL_SAI_xCR2(tx),
163 			   FSL_SAI_CR2_MSEL_MASK, val_cr2);
164 
165 	return 0;
166 }
167 
168 static int fsl_sai_set_dai_sysclk(struct snd_soc_dai *cpu_dai,
169 		int clk_id, unsigned int freq, int dir)
170 {
171 	int ret;
172 
173 	if (dir == SND_SOC_CLOCK_IN)
174 		return 0;
175 
176 	ret = fsl_sai_set_dai_sysclk_tr(cpu_dai, clk_id, freq,
177 					FSL_FMT_TRANSMITTER);
178 	if (ret) {
179 		dev_err(cpu_dai->dev, "Cannot set tx sysclk: %d\n", ret);
180 		return ret;
181 	}
182 
183 	ret = fsl_sai_set_dai_sysclk_tr(cpu_dai, clk_id, freq,
184 					FSL_FMT_RECEIVER);
185 	if (ret)
186 		dev_err(cpu_dai->dev, "Cannot set rx sysclk: %d\n", ret);
187 
188 	return ret;
189 }
190 
191 static int fsl_sai_set_dai_fmt_tr(struct snd_soc_dai *cpu_dai,
192 				unsigned int fmt, int fsl_dir)
193 {
194 	struct fsl_sai *sai = snd_soc_dai_get_drvdata(cpu_dai);
195 	bool tx = fsl_dir == FSL_FMT_TRANSMITTER;
196 	u32 val_cr2 = 0, val_cr4 = 0;
197 
198 	if (!sai->is_lsb_first)
199 		val_cr4 |= FSL_SAI_CR4_MF;
200 
201 	/* DAI mode */
202 	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
203 	case SND_SOC_DAIFMT_I2S:
204 		/*
205 		 * Frame low, 1clk before data, one word length for frame sync,
206 		 * frame sync starts one serial clock cycle earlier,
207 		 * that is, together with the last bit of the previous
208 		 * data word.
209 		 */
210 		val_cr2 |= FSL_SAI_CR2_BCP;
211 		val_cr4 |= FSL_SAI_CR4_FSE | FSL_SAI_CR4_FSP;
212 		break;
213 	case SND_SOC_DAIFMT_LEFT_J:
214 		/*
215 		 * Frame high, one word length for frame sync,
216 		 * frame sync asserts with the first bit of the frame.
217 		 */
218 		val_cr2 |= FSL_SAI_CR2_BCP;
219 		break;
220 	case SND_SOC_DAIFMT_DSP_A:
221 		/*
222 		 * Frame high, 1clk before data, one bit for frame sync,
223 		 * frame sync starts one serial clock cycle earlier,
224 		 * that is, together with the last bit of the previous
225 		 * data word.
226 		 */
227 		val_cr2 |= FSL_SAI_CR2_BCP;
228 		val_cr4 |= FSL_SAI_CR4_FSE;
229 		sai->is_dsp_mode = true;
230 		break;
231 	case SND_SOC_DAIFMT_DSP_B:
232 		/*
233 		 * Frame high, one bit for frame sync,
234 		 * frame sync asserts with the first bit of the frame.
235 		 */
236 		val_cr2 |= FSL_SAI_CR2_BCP;
237 		sai->is_dsp_mode = true;
238 		break;
239 	case SND_SOC_DAIFMT_RIGHT_J:
240 		/* To be done */
241 	default:
242 		return -EINVAL;
243 	}
244 
245 	/* DAI clock inversion */
246 	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
247 	case SND_SOC_DAIFMT_IB_IF:
248 		/* Invert both clocks */
249 		val_cr2 ^= FSL_SAI_CR2_BCP;
250 		val_cr4 ^= FSL_SAI_CR4_FSP;
251 		break;
252 	case SND_SOC_DAIFMT_IB_NF:
253 		/* Invert bit clock */
254 		val_cr2 ^= FSL_SAI_CR2_BCP;
255 		break;
256 	case SND_SOC_DAIFMT_NB_IF:
257 		/* Invert frame clock */
258 		val_cr4 ^= FSL_SAI_CR4_FSP;
259 		break;
260 	case SND_SOC_DAIFMT_NB_NF:
261 		/* Nothing to do for both normal cases */
262 		break;
263 	default:
264 		return -EINVAL;
265 	}
266 
267 	/* DAI clock master masks */
268 	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
269 	case SND_SOC_DAIFMT_CBS_CFS:
270 		val_cr2 |= FSL_SAI_CR2_BCD_MSTR;
271 		val_cr4 |= FSL_SAI_CR4_FSD_MSTR;
272 		sai->is_slave_mode = false;
273 		break;
274 	case SND_SOC_DAIFMT_CBM_CFM:
275 		sai->is_slave_mode = true;
276 		break;
277 	case SND_SOC_DAIFMT_CBS_CFM:
278 		val_cr2 |= FSL_SAI_CR2_BCD_MSTR;
279 		sai->is_slave_mode = false;
280 		break;
281 	case SND_SOC_DAIFMT_CBM_CFS:
282 		val_cr4 |= FSL_SAI_CR4_FSD_MSTR;
283 		sai->is_slave_mode = true;
284 		break;
285 	default:
286 		return -EINVAL;
287 	}
288 
289 	regmap_update_bits(sai->regmap, FSL_SAI_xCR2(tx),
290 			   FSL_SAI_CR2_BCP | FSL_SAI_CR2_BCD_MSTR, val_cr2);
291 	regmap_update_bits(sai->regmap, FSL_SAI_xCR4(tx),
292 			   FSL_SAI_CR4_MF | FSL_SAI_CR4_FSE |
293 			   FSL_SAI_CR4_FSP | FSL_SAI_CR4_FSD_MSTR, val_cr4);
294 
295 	return 0;
296 }
297 
298 static int fsl_sai_set_dai_fmt(struct snd_soc_dai *cpu_dai, unsigned int fmt)
299 {
300 	int ret;
301 
302 	ret = fsl_sai_set_dai_fmt_tr(cpu_dai, fmt, FSL_FMT_TRANSMITTER);
303 	if (ret) {
304 		dev_err(cpu_dai->dev, "Cannot set tx format: %d\n", ret);
305 		return ret;
306 	}
307 
308 	ret = fsl_sai_set_dai_fmt_tr(cpu_dai, fmt, FSL_FMT_RECEIVER);
309 	if (ret)
310 		dev_err(cpu_dai->dev, "Cannot set rx format: %d\n", ret);
311 
312 	return ret;
313 }
314 
315 static int fsl_sai_set_bclk(struct snd_soc_dai *dai, bool tx, u32 freq)
316 {
317 	struct fsl_sai *sai = snd_soc_dai_get_drvdata(dai);
318 	unsigned long clk_rate;
319 	u32 savediv = 0, ratio, savesub = freq;
320 	u32 id;
321 	int ret = 0;
322 
323 	/* Don't apply to slave mode */
324 	if (sai->is_slave_mode)
325 		return 0;
326 
327 	for (id = 0; id < FSL_SAI_MCLK_MAX; id++) {
328 		clk_rate = clk_get_rate(sai->mclk_clk[id]);
329 		if (!clk_rate)
330 			continue;
331 
332 		ratio = clk_rate / freq;
333 
334 		ret = clk_rate - ratio * freq;
335 
336 		/*
337 		 * Drop the source that can not be
338 		 * divided into the required rate.
339 		 */
340 		if (ret != 0 && clk_rate / ret < 1000)
341 			continue;
342 
343 		dev_dbg(dai->dev,
344 			"ratio %d for freq %dHz based on clock %ldHz\n",
345 			ratio, freq, clk_rate);
346 
347 		if (ratio % 2 == 0 && ratio >= 2 && ratio <= 512)
348 			ratio /= 2;
349 		else
350 			continue;
351 
352 		if (ret < savesub) {
353 			savediv = ratio;
354 			sai->mclk_id[tx] = id;
355 			savesub = ret;
356 		}
357 
358 		if (ret == 0)
359 			break;
360 	}
361 
362 	if (savediv == 0) {
363 		dev_err(dai->dev, "failed to derive required %cx rate: %d\n",
364 				tx ? 'T' : 'R', freq);
365 		return -EINVAL;
366 	}
367 
368 	/*
369 	 * 1) For Asynchronous mode, we must set RCR2 register for capture, and
370 	 *    set TCR2 register for playback.
371 	 * 2) For Tx sync with Rx clock, we must set RCR2 register for playback
372 	 *    and capture.
373 	 * 3) For Rx sync with Tx clock, we must set TCR2 register for playback
374 	 *    and capture.
375 	 * 4) For Tx and Rx are both Synchronous with another SAI, we just
376 	 *    ignore it.
377 	 */
378 	if ((sai->synchronous[TX] && !sai->synchronous[RX]) ||
379 	    (!tx && !sai->synchronous[RX])) {
380 		regmap_update_bits(sai->regmap, FSL_SAI_RCR2,
381 				   FSL_SAI_CR2_MSEL_MASK,
382 				   FSL_SAI_CR2_MSEL(sai->mclk_id[tx]));
383 		regmap_update_bits(sai->regmap, FSL_SAI_RCR2,
384 				   FSL_SAI_CR2_DIV_MASK, savediv - 1);
385 	} else if ((sai->synchronous[RX] && !sai->synchronous[TX]) ||
386 		   (tx && !sai->synchronous[TX])) {
387 		regmap_update_bits(sai->regmap, FSL_SAI_TCR2,
388 				   FSL_SAI_CR2_MSEL_MASK,
389 				   FSL_SAI_CR2_MSEL(sai->mclk_id[tx]));
390 		regmap_update_bits(sai->regmap, FSL_SAI_TCR2,
391 				   FSL_SAI_CR2_DIV_MASK, savediv - 1);
392 	}
393 
394 	dev_dbg(dai->dev, "best fit: clock id=%d, div=%d, deviation =%d\n",
395 			sai->mclk_id[tx], savediv, savesub);
396 
397 	return 0;
398 }
399 
400 static int fsl_sai_hw_params(struct snd_pcm_substream *substream,
401 		struct snd_pcm_hw_params *params,
402 		struct snd_soc_dai *cpu_dai)
403 {
404 	struct fsl_sai *sai = snd_soc_dai_get_drvdata(cpu_dai);
405 	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
406 	unsigned int channels = params_channels(params);
407 	u32 word_width = params_width(params);
408 	u32 val_cr4 = 0, val_cr5 = 0;
409 	u32 slots = (channels == 1) ? 2 : channels;
410 	u32 slot_width = word_width;
411 	int ret;
412 
413 	if (sai->slots)
414 		slots = sai->slots;
415 
416 	if (sai->slot_width)
417 		slot_width = sai->slot_width;
418 
419 	if (!sai->is_slave_mode) {
420 		ret = fsl_sai_set_bclk(cpu_dai, tx,
421 				slots * slot_width * params_rate(params));
422 		if (ret)
423 			return ret;
424 
425 		/* Do not enable the clock if it is already enabled */
426 		if (!(sai->mclk_streams & BIT(substream->stream))) {
427 			ret = clk_prepare_enable(sai->mclk_clk[sai->mclk_id[tx]]);
428 			if (ret)
429 				return ret;
430 
431 			sai->mclk_streams |= BIT(substream->stream);
432 		}
433 	}
434 
435 	if (!sai->is_dsp_mode)
436 		val_cr4 |= FSL_SAI_CR4_SYWD(slot_width);
437 
438 	val_cr5 |= FSL_SAI_CR5_WNW(slot_width);
439 	val_cr5 |= FSL_SAI_CR5_W0W(slot_width);
440 
441 	if (sai->is_lsb_first)
442 		val_cr5 |= FSL_SAI_CR5_FBT(0);
443 	else
444 		val_cr5 |= FSL_SAI_CR5_FBT(word_width - 1);
445 
446 	val_cr4 |= FSL_SAI_CR4_FRSZ(slots);
447 
448 	/*
449 	 * For SAI master mode, when Tx(Rx) sync with Rx(Tx) clock, Rx(Tx) will
450 	 * generate bclk and frame clock for Tx(Rx), we should set RCR4(TCR4),
451 	 * RCR5(TCR5) and RMR(TMR) for playback(capture), or there will be sync
452 	 * error.
453 	 */
454 
455 	if (!sai->is_slave_mode) {
456 		if (!sai->synchronous[TX] && sai->synchronous[RX] && !tx) {
457 			regmap_update_bits(sai->regmap, FSL_SAI_TCR4,
458 				FSL_SAI_CR4_SYWD_MASK | FSL_SAI_CR4_FRSZ_MASK,
459 				val_cr4);
460 			regmap_update_bits(sai->regmap, FSL_SAI_TCR5,
461 				FSL_SAI_CR5_WNW_MASK | FSL_SAI_CR5_W0W_MASK |
462 				FSL_SAI_CR5_FBT_MASK, val_cr5);
463 			regmap_write(sai->regmap, FSL_SAI_TMR,
464 				~0UL - ((1 << channels) - 1));
465 		} else if (!sai->synchronous[RX] && sai->synchronous[TX] && tx) {
466 			regmap_update_bits(sai->regmap, FSL_SAI_RCR4,
467 				FSL_SAI_CR4_SYWD_MASK | FSL_SAI_CR4_FRSZ_MASK,
468 				val_cr4);
469 			regmap_update_bits(sai->regmap, FSL_SAI_RCR5,
470 				FSL_SAI_CR5_WNW_MASK | FSL_SAI_CR5_W0W_MASK |
471 				FSL_SAI_CR5_FBT_MASK, val_cr5);
472 			regmap_write(sai->regmap, FSL_SAI_RMR,
473 				~0UL - ((1 << channels) - 1));
474 		}
475 	}
476 
477 	regmap_update_bits(sai->regmap, FSL_SAI_xCR4(tx),
478 			   FSL_SAI_CR4_SYWD_MASK | FSL_SAI_CR4_FRSZ_MASK,
479 			   val_cr4);
480 	regmap_update_bits(sai->regmap, FSL_SAI_xCR5(tx),
481 			   FSL_SAI_CR5_WNW_MASK | FSL_SAI_CR5_W0W_MASK |
482 			   FSL_SAI_CR5_FBT_MASK, val_cr5);
483 	regmap_write(sai->regmap, FSL_SAI_xMR(tx), ~0UL - ((1 << channels) - 1));
484 
485 	return 0;
486 }
487 
488 static int fsl_sai_hw_free(struct snd_pcm_substream *substream,
489 		struct snd_soc_dai *cpu_dai)
490 {
491 	struct fsl_sai *sai = snd_soc_dai_get_drvdata(cpu_dai);
492 	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
493 
494 	if (!sai->is_slave_mode &&
495 			sai->mclk_streams & BIT(substream->stream)) {
496 		clk_disable_unprepare(sai->mclk_clk[sai->mclk_id[tx]]);
497 		sai->mclk_streams &= ~BIT(substream->stream);
498 	}
499 
500 	return 0;
501 }
502 
503 
504 static int fsl_sai_trigger(struct snd_pcm_substream *substream, int cmd,
505 		struct snd_soc_dai *cpu_dai)
506 {
507 	struct fsl_sai *sai = snd_soc_dai_get_drvdata(cpu_dai);
508 	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
509 	u32 xcsr, count = 100;
510 
511 	/*
512 	 * Asynchronous mode: Clear SYNC for both Tx and Rx.
513 	 * Rx sync with Tx clocks: Clear SYNC for Tx, set it for Rx.
514 	 * Tx sync with Rx clocks: Clear SYNC for Rx, set it for Tx.
515 	 */
516 	regmap_update_bits(sai->regmap, FSL_SAI_TCR2, FSL_SAI_CR2_SYNC,
517 		           sai->synchronous[TX] ? FSL_SAI_CR2_SYNC : 0);
518 	regmap_update_bits(sai->regmap, FSL_SAI_RCR2, FSL_SAI_CR2_SYNC,
519 			   sai->synchronous[RX] ? FSL_SAI_CR2_SYNC : 0);
520 
521 	/*
522 	 * It is recommended that the transmitter is the last enabled
523 	 * and the first disabled.
524 	 */
525 	switch (cmd) {
526 	case SNDRV_PCM_TRIGGER_START:
527 	case SNDRV_PCM_TRIGGER_RESUME:
528 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
529 		regmap_update_bits(sai->regmap, FSL_SAI_xCSR(tx),
530 				   FSL_SAI_CSR_FRDE, FSL_SAI_CSR_FRDE);
531 
532 		regmap_update_bits(sai->regmap, FSL_SAI_RCSR,
533 				   FSL_SAI_CSR_TERE, FSL_SAI_CSR_TERE);
534 		regmap_update_bits(sai->regmap, FSL_SAI_TCSR,
535 				   FSL_SAI_CSR_TERE, FSL_SAI_CSR_TERE);
536 
537 		regmap_update_bits(sai->regmap, FSL_SAI_xCSR(tx),
538 				   FSL_SAI_CSR_xIE_MASK, FSL_SAI_FLAGS);
539 		break;
540 	case SNDRV_PCM_TRIGGER_STOP:
541 	case SNDRV_PCM_TRIGGER_SUSPEND:
542 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
543 		regmap_update_bits(sai->regmap, FSL_SAI_xCSR(tx),
544 				   FSL_SAI_CSR_FRDE, 0);
545 		regmap_update_bits(sai->regmap, FSL_SAI_xCSR(tx),
546 				   FSL_SAI_CSR_xIE_MASK, 0);
547 
548 		/* Check if the opposite FRDE is also disabled */
549 		regmap_read(sai->regmap, FSL_SAI_xCSR(!tx), &xcsr);
550 		if (!(xcsr & FSL_SAI_CSR_FRDE)) {
551 			/* Disable both directions and reset their FIFOs */
552 			regmap_update_bits(sai->regmap, FSL_SAI_TCSR,
553 					   FSL_SAI_CSR_TERE, 0);
554 			regmap_update_bits(sai->regmap, FSL_SAI_RCSR,
555 					   FSL_SAI_CSR_TERE, 0);
556 
557 			/* TERE will remain set till the end of current frame */
558 			do {
559 				udelay(10);
560 				regmap_read(sai->regmap, FSL_SAI_xCSR(tx), &xcsr);
561 			} while (--count && xcsr & FSL_SAI_CSR_TERE);
562 
563 			regmap_update_bits(sai->regmap, FSL_SAI_TCSR,
564 					   FSL_SAI_CSR_FR, FSL_SAI_CSR_FR);
565 			regmap_update_bits(sai->regmap, FSL_SAI_RCSR,
566 					   FSL_SAI_CSR_FR, FSL_SAI_CSR_FR);
567 
568 			/*
569 			 * For sai master mode, after several open/close sai,
570 			 * there will be no frame clock, and can't recover
571 			 * anymore. Add software reset to fix this issue.
572 			 * This is a hardware bug, and will be fix in the
573 			 * next sai version.
574 			 */
575 			if (!sai->is_slave_mode) {
576 				/* Software Reset for both Tx and Rx */
577 				regmap_write(sai->regmap,
578 					     FSL_SAI_TCSR, FSL_SAI_CSR_SR);
579 				regmap_write(sai->regmap,
580 					     FSL_SAI_RCSR, FSL_SAI_CSR_SR);
581 				/* Clear SR bit to finish the reset */
582 				regmap_write(sai->regmap, FSL_SAI_TCSR, 0);
583 				regmap_write(sai->regmap, FSL_SAI_RCSR, 0);
584 			}
585 		}
586 		break;
587 	default:
588 		return -EINVAL;
589 	}
590 
591 	return 0;
592 }
593 
594 static int fsl_sai_startup(struct snd_pcm_substream *substream,
595 		struct snd_soc_dai *cpu_dai)
596 {
597 	struct fsl_sai *sai = snd_soc_dai_get_drvdata(cpu_dai);
598 	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
599 	struct device *dev = &sai->pdev->dev;
600 	int ret;
601 
602 	ret = clk_prepare_enable(sai->bus_clk);
603 	if (ret) {
604 		dev_err(dev, "failed to enable bus clock: %d\n", ret);
605 		return ret;
606 	}
607 
608 	regmap_update_bits(sai->regmap, FSL_SAI_xCR3(tx), FSL_SAI_CR3_TRCE,
609 			   FSL_SAI_CR3_TRCE);
610 
611 	ret = snd_pcm_hw_constraint_list(substream->runtime, 0,
612 			SNDRV_PCM_HW_PARAM_RATE, &fsl_sai_rate_constraints);
613 
614 	return ret;
615 }
616 
617 static void fsl_sai_shutdown(struct snd_pcm_substream *substream,
618 		struct snd_soc_dai *cpu_dai)
619 {
620 	struct fsl_sai *sai = snd_soc_dai_get_drvdata(cpu_dai);
621 	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
622 
623 	regmap_update_bits(sai->regmap, FSL_SAI_xCR3(tx), FSL_SAI_CR3_TRCE, 0);
624 
625 	clk_disable_unprepare(sai->bus_clk);
626 }
627 
628 static const struct snd_soc_dai_ops fsl_sai_pcm_dai_ops = {
629 	.set_sysclk	= fsl_sai_set_dai_sysclk,
630 	.set_fmt	= fsl_sai_set_dai_fmt,
631 	.set_tdm_slot	= fsl_sai_set_dai_tdm_slot,
632 	.hw_params	= fsl_sai_hw_params,
633 	.hw_free	= fsl_sai_hw_free,
634 	.trigger	= fsl_sai_trigger,
635 	.startup	= fsl_sai_startup,
636 	.shutdown	= fsl_sai_shutdown,
637 };
638 
639 static int fsl_sai_dai_probe(struct snd_soc_dai *cpu_dai)
640 {
641 	struct fsl_sai *sai = dev_get_drvdata(cpu_dai->dev);
642 
643 	/* Software Reset for both Tx and Rx */
644 	regmap_write(sai->regmap, FSL_SAI_TCSR, FSL_SAI_CSR_SR);
645 	regmap_write(sai->regmap, FSL_SAI_RCSR, FSL_SAI_CSR_SR);
646 	/* Clear SR bit to finish the reset */
647 	regmap_write(sai->regmap, FSL_SAI_TCSR, 0);
648 	regmap_write(sai->regmap, FSL_SAI_RCSR, 0);
649 
650 	regmap_update_bits(sai->regmap, FSL_SAI_TCR1, FSL_SAI_CR1_RFW_MASK,
651 			   FSL_SAI_MAXBURST_TX * 2);
652 	regmap_update_bits(sai->regmap, FSL_SAI_RCR1, FSL_SAI_CR1_RFW_MASK,
653 			   FSL_SAI_MAXBURST_RX - 1);
654 
655 	snd_soc_dai_init_dma_data(cpu_dai, &sai->dma_params_tx,
656 				&sai->dma_params_rx);
657 
658 	snd_soc_dai_set_drvdata(cpu_dai, sai);
659 
660 	return 0;
661 }
662 
663 static struct snd_soc_dai_driver fsl_sai_dai = {
664 	.probe = fsl_sai_dai_probe,
665 	.playback = {
666 		.stream_name = "CPU-Playback",
667 		.channels_min = 1,
668 		.channels_max = 32,
669 		.rate_min = 8000,
670 		.rate_max = 192000,
671 		.rates = SNDRV_PCM_RATE_KNOT,
672 		.formats = FSL_SAI_FORMATS,
673 	},
674 	.capture = {
675 		.stream_name = "CPU-Capture",
676 		.channels_min = 1,
677 		.channels_max = 32,
678 		.rate_min = 8000,
679 		.rate_max = 192000,
680 		.rates = SNDRV_PCM_RATE_KNOT,
681 		.formats = FSL_SAI_FORMATS,
682 	},
683 	.ops = &fsl_sai_pcm_dai_ops,
684 };
685 
686 static const struct snd_soc_component_driver fsl_component = {
687 	.name           = "fsl-sai",
688 };
689 
690 static struct reg_default fsl_sai_reg_defaults[] = {
691 	{FSL_SAI_TCR1, 0},
692 	{FSL_SAI_TCR2, 0},
693 	{FSL_SAI_TCR3, 0},
694 	{FSL_SAI_TCR4, 0},
695 	{FSL_SAI_TCR5, 0},
696 	{FSL_SAI_TDR,  0},
697 	{FSL_SAI_TMR,  0},
698 	{FSL_SAI_RCR1, 0},
699 	{FSL_SAI_RCR2, 0},
700 	{FSL_SAI_RCR3, 0},
701 	{FSL_SAI_RCR4, 0},
702 	{FSL_SAI_RCR5, 0},
703 	{FSL_SAI_RMR,  0},
704 };
705 
706 static bool fsl_sai_readable_reg(struct device *dev, unsigned int reg)
707 {
708 	switch (reg) {
709 	case FSL_SAI_TCSR:
710 	case FSL_SAI_TCR1:
711 	case FSL_SAI_TCR2:
712 	case FSL_SAI_TCR3:
713 	case FSL_SAI_TCR4:
714 	case FSL_SAI_TCR5:
715 	case FSL_SAI_TFR:
716 	case FSL_SAI_TMR:
717 	case FSL_SAI_RCSR:
718 	case FSL_SAI_RCR1:
719 	case FSL_SAI_RCR2:
720 	case FSL_SAI_RCR3:
721 	case FSL_SAI_RCR4:
722 	case FSL_SAI_RCR5:
723 	case FSL_SAI_RDR:
724 	case FSL_SAI_RFR:
725 	case FSL_SAI_RMR:
726 		return true;
727 	default:
728 		return false;
729 	}
730 }
731 
732 static bool fsl_sai_volatile_reg(struct device *dev, unsigned int reg)
733 {
734 	switch (reg) {
735 	case FSL_SAI_TCSR:
736 	case FSL_SAI_RCSR:
737 	case FSL_SAI_TFR:
738 	case FSL_SAI_RFR:
739 	case FSL_SAI_RDR:
740 		return true;
741 	default:
742 		return false;
743 	}
744 }
745 
746 static bool fsl_sai_writeable_reg(struct device *dev, unsigned int reg)
747 {
748 	switch (reg) {
749 	case FSL_SAI_TCSR:
750 	case FSL_SAI_TCR1:
751 	case FSL_SAI_TCR2:
752 	case FSL_SAI_TCR3:
753 	case FSL_SAI_TCR4:
754 	case FSL_SAI_TCR5:
755 	case FSL_SAI_TDR:
756 	case FSL_SAI_TMR:
757 	case FSL_SAI_RCSR:
758 	case FSL_SAI_RCR1:
759 	case FSL_SAI_RCR2:
760 	case FSL_SAI_RCR3:
761 	case FSL_SAI_RCR4:
762 	case FSL_SAI_RCR5:
763 	case FSL_SAI_RMR:
764 		return true;
765 	default:
766 		return false;
767 	}
768 }
769 
770 static const struct regmap_config fsl_sai_regmap_config = {
771 	.reg_bits = 32,
772 	.reg_stride = 4,
773 	.val_bits = 32,
774 
775 	.max_register = FSL_SAI_RMR,
776 	.reg_defaults = fsl_sai_reg_defaults,
777 	.num_reg_defaults = ARRAY_SIZE(fsl_sai_reg_defaults),
778 	.readable_reg = fsl_sai_readable_reg,
779 	.volatile_reg = fsl_sai_volatile_reg,
780 	.writeable_reg = fsl_sai_writeable_reg,
781 	.cache_type = REGCACHE_FLAT,
782 };
783 
784 static int fsl_sai_probe(struct platform_device *pdev)
785 {
786 	struct device_node *np = pdev->dev.of_node;
787 	struct fsl_sai *sai;
788 	struct regmap *gpr;
789 	struct resource *res;
790 	void __iomem *base;
791 	char tmp[8];
792 	int irq, ret, i;
793 	int index;
794 
795 	sai = devm_kzalloc(&pdev->dev, sizeof(*sai), GFP_KERNEL);
796 	if (!sai)
797 		return -ENOMEM;
798 
799 	sai->pdev = pdev;
800 
801 	if (of_device_is_compatible(np, "fsl,imx6sx-sai") ||
802 	    of_device_is_compatible(np, "fsl,imx6ul-sai"))
803 		sai->sai_on_imx = true;
804 
805 	sai->is_lsb_first = of_property_read_bool(np, "lsb-first");
806 
807 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
808 	base = devm_ioremap_resource(&pdev->dev, res);
809 	if (IS_ERR(base))
810 		return PTR_ERR(base);
811 
812 	sai->regmap = devm_regmap_init_mmio_clk(&pdev->dev,
813 			"bus", base, &fsl_sai_regmap_config);
814 
815 	/* Compatible with old DTB cases */
816 	if (IS_ERR(sai->regmap))
817 		sai->regmap = devm_regmap_init_mmio_clk(&pdev->dev,
818 				"sai", base, &fsl_sai_regmap_config);
819 	if (IS_ERR(sai->regmap)) {
820 		dev_err(&pdev->dev, "regmap init failed\n");
821 		return PTR_ERR(sai->regmap);
822 	}
823 
824 	/* No error out for old DTB cases but only mark the clock NULL */
825 	sai->bus_clk = devm_clk_get(&pdev->dev, "bus");
826 	if (IS_ERR(sai->bus_clk)) {
827 		dev_err(&pdev->dev, "failed to get bus clock: %ld\n",
828 				PTR_ERR(sai->bus_clk));
829 		sai->bus_clk = NULL;
830 	}
831 
832 	sai->mclk_clk[0] = sai->bus_clk;
833 	for (i = 1; i < FSL_SAI_MCLK_MAX; i++) {
834 		sprintf(tmp, "mclk%d", i);
835 		sai->mclk_clk[i] = devm_clk_get(&pdev->dev, tmp);
836 		if (IS_ERR(sai->mclk_clk[i])) {
837 			dev_err(&pdev->dev, "failed to get mclk%d clock: %ld\n",
838 					i + 1, PTR_ERR(sai->mclk_clk[i]));
839 			sai->mclk_clk[i] = NULL;
840 		}
841 	}
842 
843 	irq = platform_get_irq(pdev, 0);
844 	if (irq < 0) {
845 		dev_err(&pdev->dev, "no irq for node %s\n", pdev->name);
846 		return irq;
847 	}
848 
849 	ret = devm_request_irq(&pdev->dev, irq, fsl_sai_isr, 0, np->name, sai);
850 	if (ret) {
851 		dev_err(&pdev->dev, "failed to claim irq %u\n", irq);
852 		return ret;
853 	}
854 
855 	/* Sync Tx with Rx as default by following old DT binding */
856 	sai->synchronous[RX] = true;
857 	sai->synchronous[TX] = false;
858 	fsl_sai_dai.symmetric_rates = 1;
859 	fsl_sai_dai.symmetric_channels = 1;
860 	fsl_sai_dai.symmetric_samplebits = 1;
861 
862 	if (of_find_property(np, "fsl,sai-synchronous-rx", NULL) &&
863 	    of_find_property(np, "fsl,sai-asynchronous", NULL)) {
864 		/* error out if both synchronous and asynchronous are present */
865 		dev_err(&pdev->dev, "invalid binding for synchronous mode\n");
866 		return -EINVAL;
867 	}
868 
869 	if (of_find_property(np, "fsl,sai-synchronous-rx", NULL)) {
870 		/* Sync Rx with Tx */
871 		sai->synchronous[RX] = false;
872 		sai->synchronous[TX] = true;
873 	} else if (of_find_property(np, "fsl,sai-asynchronous", NULL)) {
874 		/* Discard all settings for asynchronous mode */
875 		sai->synchronous[RX] = false;
876 		sai->synchronous[TX] = false;
877 		fsl_sai_dai.symmetric_rates = 0;
878 		fsl_sai_dai.symmetric_channels = 0;
879 		fsl_sai_dai.symmetric_samplebits = 0;
880 	}
881 
882 	if (of_find_property(np, "fsl,sai-mclk-direction-output", NULL) &&
883 	    of_device_is_compatible(np, "fsl,imx6ul-sai")) {
884 		gpr = syscon_regmap_lookup_by_compatible("fsl,imx6ul-iomuxc-gpr");
885 		if (IS_ERR(gpr)) {
886 			dev_err(&pdev->dev, "cannot find iomuxc registers\n");
887 			return PTR_ERR(gpr);
888 		}
889 
890 		index = of_alias_get_id(np, "sai");
891 		if (index < 0)
892 			return index;
893 
894 		regmap_update_bits(gpr, IOMUXC_GPR1, MCLK_DIR(index),
895 				   MCLK_DIR(index));
896 	}
897 
898 	sai->dma_params_rx.addr = res->start + FSL_SAI_RDR;
899 	sai->dma_params_tx.addr = res->start + FSL_SAI_TDR;
900 	sai->dma_params_rx.maxburst = FSL_SAI_MAXBURST_RX;
901 	sai->dma_params_tx.maxburst = FSL_SAI_MAXBURST_TX;
902 
903 	platform_set_drvdata(pdev, sai);
904 
905 	pm_runtime_enable(&pdev->dev);
906 
907 	ret = devm_snd_soc_register_component(&pdev->dev, &fsl_component,
908 			&fsl_sai_dai, 1);
909 	if (ret)
910 		return ret;
911 
912 	if (sai->sai_on_imx)
913 		return imx_pcm_dma_init(pdev, IMX_SAI_DMABUF_SIZE);
914 	else
915 		return devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);
916 }
917 
918 static int fsl_sai_remove(struct platform_device *pdev)
919 {
920 	pm_runtime_disable(&pdev->dev);
921 
922 	return 0;
923 }
924 
925 static const struct of_device_id fsl_sai_ids[] = {
926 	{ .compatible = "fsl,vf610-sai", },
927 	{ .compatible = "fsl,imx6sx-sai", },
928 	{ .compatible = "fsl,imx6ul-sai", },
929 	{ /* sentinel */ }
930 };
931 MODULE_DEVICE_TABLE(of, fsl_sai_ids);
932 
933 #ifdef CONFIG_PM
934 static int fsl_sai_runtime_suspend(struct device *dev)
935 {
936 	struct fsl_sai *sai = dev_get_drvdata(dev);
937 
938 	regcache_cache_only(sai->regmap, true);
939 	regcache_mark_dirty(sai->regmap);
940 
941 	return 0;
942 }
943 
944 static int fsl_sai_runtime_resume(struct device *dev)
945 {
946 	struct fsl_sai *sai = dev_get_drvdata(dev);
947 
948 	regcache_cache_only(sai->regmap, false);
949 	regmap_write(sai->regmap, FSL_SAI_TCSR, FSL_SAI_CSR_SR);
950 	regmap_write(sai->regmap, FSL_SAI_RCSR, FSL_SAI_CSR_SR);
951 	usleep_range(1000, 2000);
952 	regmap_write(sai->regmap, FSL_SAI_TCSR, 0);
953 	regmap_write(sai->regmap, FSL_SAI_RCSR, 0);
954 	return regcache_sync(sai->regmap);
955 }
956 #endif /* CONFIG_PM */
957 
958 static const struct dev_pm_ops fsl_sai_pm_ops = {
959 	SET_RUNTIME_PM_OPS(fsl_sai_runtime_suspend,
960 			   fsl_sai_runtime_resume, NULL)
961 	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
962 				pm_runtime_force_resume)
963 };
964 
965 static struct platform_driver fsl_sai_driver = {
966 	.probe = fsl_sai_probe,
967 	.remove = fsl_sai_remove,
968 	.driver = {
969 		.name = "fsl-sai",
970 		.pm = &fsl_sai_pm_ops,
971 		.of_match_table = fsl_sai_ids,
972 	},
973 };
974 module_platform_driver(fsl_sai_driver);
975 
976 MODULE_DESCRIPTION("Freescale Soc SAI Interface");
977 MODULE_AUTHOR("Xiubo Li, <Li.Xiubo@freescale.com>");
978 MODULE_ALIAS("platform:fsl-sai");
979 MODULE_LICENSE("GPL");
980