xref: /openbmc/linux/sound/soc/sh/rz-ssi.c (revision 63705da3)
1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // Renesas RZ/G2L ASoC Serial Sound Interface (SSIF-2) Driver
4 //
5 // Copyright (C) 2021 Renesas Electronics Corp.
6 // Copyright (C) 2019 Chris Brandt.
7 //
8 
9 #include <linux/clk.h>
10 #include <linux/dmaengine.h>
11 #include <linux/io.h>
12 #include <linux/module.h>
13 #include <linux/of_device.h>
14 #include <linux/pm_runtime.h>
15 #include <linux/reset.h>
16 #include <sound/soc.h>
17 
18 /* REGISTER OFFSET */
19 #define SSICR			0x000
20 #define SSISR			0x004
21 #define SSIFCR			0x010
22 #define SSIFSR			0x014
23 #define SSIFTDR			0x018
24 #define SSIFRDR			0x01c
25 #define SSIOFR			0x020
26 #define SSISCR			0x024
27 
28 /* SSI REGISTER BITS */
29 #define SSICR_DWL(x)		(((x) & 0x7) << 19)
30 #define SSICR_SWL(x)		(((x) & 0x7) << 16)
31 #define SSICR_MST		BIT(14)
32 #define SSICR_CKDV(x)		(((x) & 0xf) << 4)
33 
34 #define SSICR_CKS		BIT(30)
35 #define SSICR_TUIEN		BIT(29)
36 #define SSICR_TOIEN		BIT(28)
37 #define SSICR_RUIEN		BIT(27)
38 #define SSICR_ROIEN		BIT(26)
39 #define SSICR_MST		BIT(14)
40 #define SSICR_BCKP		BIT(13)
41 #define SSICR_LRCKP		BIT(12)
42 #define SSICR_CKDV(x)		(((x) & 0xf) << 4)
43 #define SSICR_TEN		BIT(1)
44 #define SSICR_REN		BIT(0)
45 
46 #define SSISR_TUIRQ		BIT(29)
47 #define SSISR_TOIRQ		BIT(28)
48 #define SSISR_RUIRQ		BIT(27)
49 #define SSISR_ROIRQ		BIT(26)
50 #define SSISR_IIRQ		BIT(25)
51 
52 #define SSIFCR_AUCKE		BIT(31)
53 #define SSIFCR_SSIRST		BIT(16)
54 #define SSIFCR_TIE		BIT(3)
55 #define SSIFCR_RIE		BIT(2)
56 #define SSIFCR_TFRST		BIT(1)
57 #define SSIFCR_RFRST		BIT(0)
58 
59 #define SSIFSR_TDC_MASK		0x3f
60 #define SSIFSR_TDC_SHIFT	24
61 #define SSIFSR_RDC_MASK		0x3f
62 #define SSIFSR_RDC_SHIFT	8
63 
64 #define SSIFSR_TDC(x)		(((x) & 0x1f) << 24)
65 #define SSIFSR_TDE		BIT(16)
66 #define SSIFSR_RDC(x)		(((x) & 0x1f) << 8)
67 #define SSIFSR_RDF		BIT(0)
68 
69 #define SSIOFR_LRCONT		BIT(8)
70 
71 #define SSISCR_TDES(x)		(((x) & 0x1f) << 8)
72 #define SSISCR_RDFS(x)		(((x) & 0x1f) << 0)
73 
74 /* Pre allocated buffers sizes */
75 #define PREALLOC_BUFFER		(SZ_32K)
76 #define PREALLOC_BUFFER_MAX	(SZ_32K)
77 
78 #define SSI_RATES		SNDRV_PCM_RATE_8000_48000 /* 8k-44.1kHz */
79 #define SSI_FMTS		SNDRV_PCM_FMTBIT_S16_LE
80 #define SSI_CHAN_MIN		2
81 #define SSI_CHAN_MAX		2
82 #define SSI_FIFO_DEPTH		32
83 
84 struct rz_ssi_priv;
85 
86 struct rz_ssi_stream {
87 	struct rz_ssi_priv *priv;
88 	struct snd_pcm_substream *substream;
89 	int fifo_sample_size;	/* sample capacity of SSI FIFO */
90 	int dma_buffer_pos;	/* The address for the next DMA descriptor */
91 	int period_counter;	/* for keeping track of periods transferred */
92 	int sample_width;
93 	int buffer_pos;		/* current frame position in the buffer */
94 	int running;		/* 0=stopped, 1=running */
95 
96 	int uerr_num;
97 	int oerr_num;
98 
99 	struct dma_chan *dma_ch;
100 
101 	int (*transfer)(struct rz_ssi_priv *ssi, struct rz_ssi_stream *strm);
102 };
103 
104 struct rz_ssi_priv {
105 	void __iomem *base;
106 	struct platform_device *pdev;
107 	struct reset_control *rstc;
108 	struct device *dev;
109 	struct clk *sfr_clk;
110 	struct clk *clk;
111 
112 	phys_addr_t phys;
113 	int irq_int;
114 	int irq_tx;
115 	int irq_rx;
116 
117 	spinlock_t lock;
118 
119 	/*
120 	 * The SSI supports full-duplex transmission and reception.
121 	 * However, if an error occurs, channel reset (both transmission
122 	 * and reception reset) is required.
123 	 * So it is better to use as half-duplex (playing and recording
124 	 * should be done on separate channels).
125 	 */
126 	struct rz_ssi_stream playback;
127 	struct rz_ssi_stream capture;
128 
129 	/* clock */
130 	unsigned long audio_mck;
131 	unsigned long audio_clk_1;
132 	unsigned long audio_clk_2;
133 
134 	bool lrckp_fsync_fall;	/* LR clock polarity (SSICR.LRCKP) */
135 	bool bckp_rise;	/* Bit clock polarity (SSICR.BCKP) */
136 	bool dma_rt;
137 };
138 
139 static void rz_ssi_dma_complete(void *data);
140 
141 static void rz_ssi_reg_writel(struct rz_ssi_priv *priv, uint reg, u32 data)
142 {
143 	writel(data, (priv->base + reg));
144 }
145 
146 static u32 rz_ssi_reg_readl(struct rz_ssi_priv *priv, uint reg)
147 {
148 	return readl(priv->base + reg);
149 }
150 
151 static void rz_ssi_reg_mask_setl(struct rz_ssi_priv *priv, uint reg,
152 				 u32 bclr, u32 bset)
153 {
154 	u32 val;
155 
156 	val = readl(priv->base + reg);
157 	val = (val & ~bclr) | bset;
158 	writel(val, (priv->base + reg));
159 }
160 
161 static inline struct snd_soc_dai *
162 rz_ssi_get_dai(struct snd_pcm_substream *substream)
163 {
164 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
165 
166 	return asoc_rtd_to_cpu(rtd, 0);
167 }
168 
169 static inline bool rz_ssi_stream_is_play(struct rz_ssi_priv *ssi,
170 					 struct snd_pcm_substream *substream)
171 {
172 	return substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
173 }
174 
175 static inline struct rz_ssi_stream *
176 rz_ssi_stream_get(struct rz_ssi_priv *ssi, struct snd_pcm_substream *substream)
177 {
178 	struct rz_ssi_stream *stream = &ssi->playback;
179 
180 	if (substream->stream != SNDRV_PCM_STREAM_PLAYBACK)
181 		stream = &ssi->capture;
182 
183 	return stream;
184 }
185 
186 static inline bool rz_ssi_is_dma_enabled(struct rz_ssi_priv *ssi)
187 {
188 	return (ssi->playback.dma_ch && (ssi->dma_rt || ssi->capture.dma_ch));
189 }
190 
191 static int rz_ssi_stream_is_valid(struct rz_ssi_priv *ssi,
192 				  struct rz_ssi_stream *strm)
193 {
194 	unsigned long flags;
195 	int ret;
196 
197 	spin_lock_irqsave(&ssi->lock, flags);
198 	ret = !!(strm->substream && strm->substream->runtime);
199 	spin_unlock_irqrestore(&ssi->lock, flags);
200 
201 	return ret;
202 }
203 
204 static int rz_ssi_stream_init(struct rz_ssi_priv *ssi,
205 			      struct rz_ssi_stream *strm,
206 			      struct snd_pcm_substream *substream)
207 {
208 	struct snd_pcm_runtime *runtime = substream->runtime;
209 
210 	strm->substream = substream;
211 	strm->sample_width = samples_to_bytes(runtime, 1);
212 	strm->dma_buffer_pos = 0;
213 	strm->period_counter = 0;
214 	strm->buffer_pos = 0;
215 
216 	strm->oerr_num = 0;
217 	strm->uerr_num = 0;
218 	strm->running = 0;
219 
220 	/* fifo init */
221 	strm->fifo_sample_size = SSI_FIFO_DEPTH;
222 
223 	return 0;
224 }
225 
226 static void rz_ssi_stream_quit(struct rz_ssi_priv *ssi,
227 			       struct rz_ssi_stream *strm)
228 {
229 	struct snd_soc_dai *dai = rz_ssi_get_dai(strm->substream);
230 	unsigned long flags;
231 
232 	spin_lock_irqsave(&ssi->lock, flags);
233 	strm->substream = NULL;
234 	spin_unlock_irqrestore(&ssi->lock, flags);
235 
236 	if (strm->oerr_num > 0)
237 		dev_info(dai->dev, "overrun = %d\n", strm->oerr_num);
238 
239 	if (strm->uerr_num > 0)
240 		dev_info(dai->dev, "underrun = %d\n", strm->uerr_num);
241 }
242 
243 static int rz_ssi_clk_setup(struct rz_ssi_priv *ssi, unsigned int rate,
244 			    unsigned int channels)
245 {
246 	static s8 ckdv[16] = { 1,  2,  4,  8, 16, 32, 64, 128,
247 			       6, 12, 24, 48, 96, -1, -1, -1 };
248 	unsigned int channel_bits = 32;	/* System Word Length */
249 	unsigned long bclk_rate = rate * channels * channel_bits;
250 	unsigned int div;
251 	unsigned int i;
252 	u32 ssicr = 0;
253 	u32 clk_ckdv;
254 
255 	/* Clear AUCKE so we can set MST */
256 	rz_ssi_reg_writel(ssi, SSIFCR, 0);
257 
258 	/* Continue to output LRCK pin even when idle */
259 	rz_ssi_reg_writel(ssi, SSIOFR, SSIOFR_LRCONT);
260 	if (ssi->audio_clk_1 && ssi->audio_clk_2) {
261 		if (ssi->audio_clk_1 % bclk_rate)
262 			ssi->audio_mck = ssi->audio_clk_2;
263 		else
264 			ssi->audio_mck = ssi->audio_clk_1;
265 	}
266 
267 	/* Clock setting */
268 	ssicr |= SSICR_MST;
269 	if (ssi->audio_mck == ssi->audio_clk_1)
270 		ssicr |= SSICR_CKS;
271 	if (ssi->bckp_rise)
272 		ssicr |= SSICR_BCKP;
273 	if (ssi->lrckp_fsync_fall)
274 		ssicr |= SSICR_LRCKP;
275 
276 	/* Determine the clock divider */
277 	clk_ckdv = 0;
278 	div = ssi->audio_mck / bclk_rate;
279 	/* try to find an match */
280 	for (i = 0; i < ARRAY_SIZE(ckdv); i++) {
281 		if (ckdv[i] == div) {
282 			clk_ckdv = i;
283 			break;
284 		}
285 	}
286 
287 	if (i == ARRAY_SIZE(ckdv)) {
288 		dev_err(ssi->dev, "Rate not divisible by audio clock source\n");
289 		return -EINVAL;
290 	}
291 
292 	/*
293 	 * DWL: Data Word Length = 16 bits
294 	 * SWL: System Word Length = 32 bits
295 	 */
296 	ssicr |= SSICR_CKDV(clk_ckdv);
297 	ssicr |= SSICR_DWL(1) | SSICR_SWL(3);
298 	rz_ssi_reg_writel(ssi, SSICR, ssicr);
299 	rz_ssi_reg_writel(ssi, SSIFCR,
300 			  (SSIFCR_AUCKE | SSIFCR_TFRST | SSIFCR_RFRST));
301 
302 	return 0;
303 }
304 
305 static int rz_ssi_start(struct rz_ssi_priv *ssi, struct rz_ssi_stream *strm)
306 {
307 	bool is_play = rz_ssi_stream_is_play(ssi, strm->substream);
308 	u32 ssicr, ssifcr;
309 
310 	ssicr = rz_ssi_reg_readl(ssi, SSICR);
311 	ssifcr = rz_ssi_reg_readl(ssi, SSIFCR) & ~0xF;
312 
313 	/* FIFO interrupt thresholds */
314 	if (rz_ssi_is_dma_enabled(ssi))
315 		rz_ssi_reg_writel(ssi, SSISCR, 0);
316 	else
317 		rz_ssi_reg_writel(ssi, SSISCR,
318 				  SSISCR_TDES(strm->fifo_sample_size / 2 - 1) |
319 				  SSISCR_RDFS(0));
320 
321 	/* enable IRQ */
322 	if (is_play) {
323 		ssicr |= SSICR_TUIEN | SSICR_TOIEN;
324 		ssifcr |= SSIFCR_TIE | SSIFCR_RFRST;
325 	} else {
326 		ssicr |= SSICR_RUIEN | SSICR_ROIEN;
327 		ssifcr |= SSIFCR_RIE | SSIFCR_TFRST;
328 	}
329 
330 	rz_ssi_reg_writel(ssi, SSICR, ssicr);
331 	rz_ssi_reg_writel(ssi, SSIFCR, ssifcr);
332 
333 	/* Clear all error flags */
334 	rz_ssi_reg_mask_setl(ssi, SSISR,
335 			     (SSISR_TOIRQ | SSISR_TUIRQ | SSISR_ROIRQ |
336 			      SSISR_RUIRQ), 0);
337 
338 	strm->running = 1;
339 	ssicr |= is_play ? SSICR_TEN : SSICR_REN;
340 	rz_ssi_reg_writel(ssi, SSICR, ssicr);
341 
342 	return 0;
343 }
344 
345 static int rz_ssi_stop(struct rz_ssi_priv *ssi, struct rz_ssi_stream *strm)
346 {
347 	int timeout;
348 
349 	strm->running = 0;
350 
351 	/* Disable TX/RX */
352 	rz_ssi_reg_mask_setl(ssi, SSICR, SSICR_TEN | SSICR_REN, 0);
353 
354 	/* Cancel all remaining DMA transactions */
355 	if (rz_ssi_is_dma_enabled(ssi))
356 		dmaengine_terminate_async(strm->dma_ch);
357 
358 	/* Disable irqs */
359 	rz_ssi_reg_mask_setl(ssi, SSICR, SSICR_TUIEN | SSICR_TOIEN |
360 			     SSICR_RUIEN | SSICR_ROIEN, 0);
361 	rz_ssi_reg_mask_setl(ssi, SSIFCR, SSIFCR_TIE | SSIFCR_RIE, 0);
362 
363 	/* Clear all error flags */
364 	rz_ssi_reg_mask_setl(ssi, SSISR,
365 			     (SSISR_TOIRQ | SSISR_TUIRQ | SSISR_ROIRQ |
366 			      SSISR_RUIRQ), 0);
367 
368 	/* Wait for idle */
369 	timeout = 100;
370 	while (--timeout) {
371 		if (rz_ssi_reg_readl(ssi, SSISR) & SSISR_IIRQ)
372 			break;
373 		udelay(1);
374 	}
375 
376 	if (!timeout)
377 		dev_info(ssi->dev, "timeout waiting for SSI idle\n");
378 
379 	/* Hold FIFOs in reset */
380 	rz_ssi_reg_mask_setl(ssi, SSIFCR, 0,
381 			     SSIFCR_TFRST | SSIFCR_RFRST);
382 
383 	return 0;
384 }
385 
386 static void rz_ssi_pointer_update(struct rz_ssi_stream *strm, int frames)
387 {
388 	struct snd_pcm_substream *substream = strm->substream;
389 	struct snd_pcm_runtime *runtime;
390 	int current_period;
391 
392 	if (!strm->running || !substream || !substream->runtime)
393 		return;
394 
395 	runtime = substream->runtime;
396 	strm->buffer_pos += frames;
397 	WARN_ON(strm->buffer_pos > runtime->buffer_size);
398 
399 	/* ring buffer */
400 	if (strm->buffer_pos == runtime->buffer_size)
401 		strm->buffer_pos = 0;
402 
403 	current_period = strm->buffer_pos / runtime->period_size;
404 	if (strm->period_counter != current_period) {
405 		snd_pcm_period_elapsed(strm->substream);
406 		strm->period_counter = current_period;
407 	}
408 }
409 
410 static int rz_ssi_pio_recv(struct rz_ssi_priv *ssi, struct rz_ssi_stream *strm)
411 {
412 	struct snd_pcm_substream *substream = strm->substream;
413 	struct snd_pcm_runtime *runtime;
414 	u16 *buf;
415 	int fifo_samples;
416 	int frames_left;
417 	int samples = 0;
418 	int i;
419 
420 	if (!rz_ssi_stream_is_valid(ssi, strm))
421 		return -EINVAL;
422 
423 	runtime = substream->runtime;
424 	/* frames left in this period */
425 	frames_left = runtime->period_size - (strm->buffer_pos %
426 					      runtime->period_size);
427 	if (frames_left == 0)
428 		frames_left = runtime->period_size;
429 
430 	/* Samples in RX FIFO */
431 	fifo_samples = (rz_ssi_reg_readl(ssi, SSIFSR) >>
432 			SSIFSR_RDC_SHIFT) & SSIFSR_RDC_MASK;
433 
434 	/* Only read full frames at a time */
435 	while (frames_left && (fifo_samples >= runtime->channels)) {
436 		samples += runtime->channels;
437 		fifo_samples -= runtime->channels;
438 		frames_left--;
439 	}
440 
441 	/* not enough samples yet */
442 	if (samples == 0)
443 		return 0;
444 
445 	/* calculate new buffer index */
446 	buf = (u16 *)(runtime->dma_area);
447 	buf += strm->buffer_pos * runtime->channels;
448 
449 	/* Note, only supports 16-bit samples */
450 	for (i = 0; i < samples; i++)
451 		*buf++ = (u16)(rz_ssi_reg_readl(ssi, SSIFRDR) >> 16);
452 
453 	rz_ssi_reg_mask_setl(ssi, SSIFSR, SSIFSR_RDF, 0);
454 	rz_ssi_pointer_update(strm, samples / runtime->channels);
455 
456 	/*
457 	 * If we finished this period, but there are more samples in
458 	 * the RX FIFO, call this function again
459 	 */
460 	if (frames_left == 0 && fifo_samples >= runtime->channels)
461 		rz_ssi_pio_recv(ssi, strm);
462 
463 	return 0;
464 }
465 
466 static int rz_ssi_pio_send(struct rz_ssi_priv *ssi, struct rz_ssi_stream *strm)
467 {
468 	struct snd_pcm_substream *substream = strm->substream;
469 	struct snd_pcm_runtime *runtime = substream->runtime;
470 	int sample_space;
471 	int samples = 0;
472 	int frames_left;
473 	int i;
474 	u32 ssifsr;
475 	u16 *buf;
476 
477 	if (!rz_ssi_stream_is_valid(ssi, strm))
478 		return -EINVAL;
479 
480 	/* frames left in this period */
481 	frames_left = runtime->period_size - (strm->buffer_pos %
482 					      runtime->period_size);
483 	if (frames_left == 0)
484 		frames_left = runtime->period_size;
485 
486 	sample_space = strm->fifo_sample_size;
487 	ssifsr = rz_ssi_reg_readl(ssi, SSIFSR);
488 	sample_space -= (ssifsr >> SSIFSR_TDC_SHIFT) & SSIFSR_TDC_MASK;
489 
490 	/* Only add full frames at a time */
491 	while (frames_left && (sample_space >= runtime->channels)) {
492 		samples += runtime->channels;
493 		sample_space -= runtime->channels;
494 		frames_left--;
495 	}
496 
497 	/* no space to send anything right now */
498 	if (samples == 0)
499 		return 0;
500 
501 	/* calculate new buffer index */
502 	buf = (u16 *)(runtime->dma_area);
503 	buf += strm->buffer_pos * runtime->channels;
504 
505 	/* Note, only supports 16-bit samples */
506 	for (i = 0; i < samples; i++)
507 		rz_ssi_reg_writel(ssi, SSIFTDR, ((u32)(*buf++) << 16));
508 
509 	rz_ssi_reg_mask_setl(ssi, SSIFSR, SSIFSR_TDE, 0);
510 	rz_ssi_pointer_update(strm, samples / runtime->channels);
511 
512 	return 0;
513 }
514 
515 static irqreturn_t rz_ssi_interrupt(int irq, void *data)
516 {
517 	struct rz_ssi_stream *strm = NULL;
518 	struct rz_ssi_priv *ssi = data;
519 	u32 ssisr = rz_ssi_reg_readl(ssi, SSISR);
520 
521 	if (ssi->playback.substream)
522 		strm = &ssi->playback;
523 	else if (ssi->capture.substream)
524 		strm = &ssi->capture;
525 	else
526 		return IRQ_HANDLED; /* Left over TX/RX interrupt */
527 
528 	if (irq == ssi->irq_int) { /* error or idle */
529 		if (ssisr & SSISR_TUIRQ)
530 			strm->uerr_num++;
531 		if (ssisr & SSISR_TOIRQ)
532 			strm->oerr_num++;
533 		if (ssisr & SSISR_RUIRQ)
534 			strm->uerr_num++;
535 		if (ssisr & SSISR_ROIRQ)
536 			strm->oerr_num++;
537 
538 		if (ssisr & (SSISR_TUIRQ | SSISR_TOIRQ | SSISR_RUIRQ |
539 			     SSISR_ROIRQ)) {
540 			/* Error handling */
541 			/* You must reset (stop/restart) after each interrupt */
542 			rz_ssi_stop(ssi, strm);
543 
544 			/* Clear all flags */
545 			rz_ssi_reg_mask_setl(ssi, SSISR, SSISR_TOIRQ |
546 					     SSISR_TUIRQ | SSISR_ROIRQ |
547 					     SSISR_RUIRQ, 0);
548 
549 			/* Add/remove more data */
550 			strm->transfer(ssi, strm);
551 
552 			/* Resume */
553 			rz_ssi_start(ssi, strm);
554 		}
555 	}
556 
557 	if (!strm->running)
558 		return IRQ_HANDLED;
559 
560 	/* tx data empty */
561 	if (irq == ssi->irq_tx)
562 		strm->transfer(ssi, &ssi->playback);
563 
564 	/* rx data full */
565 	if (irq == ssi->irq_rx) {
566 		strm->transfer(ssi, &ssi->capture);
567 		rz_ssi_reg_mask_setl(ssi, SSIFSR, SSIFSR_RDF, 0);
568 	}
569 
570 	return IRQ_HANDLED;
571 }
572 
573 static int rz_ssi_dma_slave_config(struct rz_ssi_priv *ssi,
574 				   struct dma_chan *dma_ch, bool is_play)
575 {
576 	struct dma_slave_config cfg;
577 
578 	memset(&cfg, 0, sizeof(cfg));
579 
580 	cfg.direction = is_play ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
581 	cfg.dst_addr = ssi->phys + SSIFTDR;
582 	cfg.src_addr = ssi->phys + SSIFRDR;
583 	cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
584 	cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
585 
586 	return dmaengine_slave_config(dma_ch, &cfg);
587 }
588 
589 static int rz_ssi_dma_transfer(struct rz_ssi_priv *ssi,
590 			       struct rz_ssi_stream *strm)
591 {
592 	struct snd_pcm_substream *substream = strm->substream;
593 	struct dma_async_tx_descriptor *desc;
594 	struct snd_pcm_runtime *runtime;
595 	enum dma_transfer_direction dir;
596 	u32 dma_paddr, dma_size;
597 	int amount;
598 
599 	if (!rz_ssi_stream_is_valid(ssi, strm))
600 		return -EINVAL;
601 
602 	runtime = substream->runtime;
603 	if (runtime->status->state == SNDRV_PCM_STATE_DRAINING)
604 		/*
605 		 * Stream is ending, so do not queue up any more DMA
606 		 * transfers otherwise we play partial sound clips
607 		 * because we can't shut off the DMA quick enough.
608 		 */
609 		return 0;
610 
611 	dir = rz_ssi_stream_is_play(ssi, substream) ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
612 
613 	/* Always transfer 1 period */
614 	amount = runtime->period_size;
615 
616 	/* DMA physical address and size */
617 	dma_paddr = runtime->dma_addr + frames_to_bytes(runtime,
618 							strm->dma_buffer_pos);
619 	dma_size = frames_to_bytes(runtime, amount);
620 	desc = dmaengine_prep_slave_single(strm->dma_ch, dma_paddr, dma_size,
621 					   dir,
622 					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
623 	if (!desc) {
624 		dev_err(ssi->dev, "dmaengine_prep_slave_single() fail\n");
625 		return -ENOMEM;
626 	}
627 
628 	desc->callback = rz_ssi_dma_complete;
629 	desc->callback_param = strm;
630 
631 	if (dmaengine_submit(desc) < 0) {
632 		dev_err(ssi->dev, "dmaengine_submit() fail\n");
633 		return -EIO;
634 	}
635 
636 	/* Update DMA pointer */
637 	strm->dma_buffer_pos += amount;
638 	if (strm->dma_buffer_pos >= runtime->buffer_size)
639 		strm->dma_buffer_pos = 0;
640 
641 	/* Start DMA */
642 	dma_async_issue_pending(strm->dma_ch);
643 
644 	return 0;
645 }
646 
647 static void rz_ssi_dma_complete(void *data)
648 {
649 	struct rz_ssi_stream *strm = (struct rz_ssi_stream *)data;
650 
651 	if (!strm->running || !strm->substream || !strm->substream->runtime)
652 		return;
653 
654 	/* Note that next DMA transaction has probably already started */
655 	rz_ssi_pointer_update(strm, strm->substream->runtime->period_size);
656 
657 	/* Queue up another DMA transaction */
658 	rz_ssi_dma_transfer(strm->priv, strm);
659 }
660 
661 static void rz_ssi_release_dma_channels(struct rz_ssi_priv *ssi)
662 {
663 	if (ssi->playback.dma_ch) {
664 		dma_release_channel(ssi->playback.dma_ch);
665 		ssi->playback.dma_ch = NULL;
666 		if (ssi->dma_rt)
667 			ssi->dma_rt = false;
668 	}
669 
670 	if (ssi->capture.dma_ch) {
671 		dma_release_channel(ssi->capture.dma_ch);
672 		ssi->capture.dma_ch = NULL;
673 	}
674 }
675 
676 static int rz_ssi_dma_request(struct rz_ssi_priv *ssi, struct device *dev)
677 {
678 	ssi->playback.dma_ch = dma_request_chan(dev, "tx");
679 	if (IS_ERR(ssi->playback.dma_ch))
680 		ssi->playback.dma_ch = NULL;
681 
682 	ssi->capture.dma_ch = dma_request_chan(dev, "rx");
683 	if (IS_ERR(ssi->capture.dma_ch))
684 		ssi->capture.dma_ch = NULL;
685 
686 	if (!ssi->playback.dma_ch && !ssi->capture.dma_ch) {
687 		ssi->playback.dma_ch = dma_request_chan(dev, "rt");
688 		if (IS_ERR(ssi->playback.dma_ch)) {
689 			ssi->playback.dma_ch = NULL;
690 			goto no_dma;
691 		}
692 
693 		ssi->dma_rt = true;
694 	}
695 
696 	if (!rz_ssi_is_dma_enabled(ssi))
697 		goto no_dma;
698 
699 	if (ssi->playback.dma_ch &&
700 	    (rz_ssi_dma_slave_config(ssi, ssi->playback.dma_ch, true) < 0))
701 		goto no_dma;
702 
703 	if (ssi->capture.dma_ch &&
704 	    (rz_ssi_dma_slave_config(ssi, ssi->capture.dma_ch, false) < 0))
705 		goto no_dma;
706 
707 	return 0;
708 
709 no_dma:
710 	rz_ssi_release_dma_channels(ssi);
711 
712 	return -ENODEV;
713 }
714 
715 static int rz_ssi_dai_trigger(struct snd_pcm_substream *substream, int cmd,
716 			      struct snd_soc_dai *dai)
717 {
718 	struct rz_ssi_priv *ssi = snd_soc_dai_get_drvdata(dai);
719 	struct rz_ssi_stream *strm = rz_ssi_stream_get(ssi, substream);
720 	int ret = 0, i, num_transfer = 1;
721 
722 	switch (cmd) {
723 	case SNDRV_PCM_TRIGGER_START:
724 		/* Soft Reset */
725 		rz_ssi_reg_mask_setl(ssi, SSIFCR, 0, SSIFCR_SSIRST);
726 		rz_ssi_reg_mask_setl(ssi, SSIFCR, SSIFCR_SSIRST, 0);
727 		udelay(5);
728 
729 		ret = rz_ssi_stream_init(ssi, strm, substream);
730 		if (ret)
731 			goto done;
732 
733 		if (ssi->dma_rt) {
734 			bool is_playback;
735 
736 			is_playback = rz_ssi_stream_is_play(ssi, substream);
737 			ret = rz_ssi_dma_slave_config(ssi, ssi->playback.dma_ch,
738 						      is_playback);
739 			/* Fallback to pio */
740 			if (ret < 0) {
741 				ssi->playback.transfer = rz_ssi_pio_send;
742 				ssi->capture.transfer = rz_ssi_pio_recv;
743 				rz_ssi_release_dma_channels(ssi);
744 			}
745 		}
746 
747 		/* For DMA, queue up multiple DMA descriptors */
748 		if (rz_ssi_is_dma_enabled(ssi))
749 			num_transfer = 4;
750 
751 		for (i = 0; i < num_transfer; i++) {
752 			ret = strm->transfer(ssi, strm);
753 			if (ret)
754 				goto done;
755 		}
756 
757 		ret = rz_ssi_start(ssi, strm);
758 		break;
759 	case SNDRV_PCM_TRIGGER_STOP:
760 		rz_ssi_stop(ssi, strm);
761 		rz_ssi_stream_quit(ssi, strm);
762 		break;
763 	}
764 
765 done:
766 	return ret;
767 }
768 
769 static int rz_ssi_dai_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
770 {
771 	struct rz_ssi_priv *ssi = snd_soc_dai_get_drvdata(dai);
772 
773 	switch (fmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK) {
774 	case SND_SOC_DAIFMT_CBC_CFC:
775 		break;
776 	default:
777 		dev_err(ssi->dev, "Codec should be clk and frame consumer\n");
778 		return -EINVAL;
779 	}
780 
781 	/*
782 	 * set clock polarity
783 	 *
784 	 * "normal" BCLK = Signal is available at rising edge of BCLK
785 	 * "normal" FSYNC = (I2S) Left ch starts with falling FSYNC edge
786 	 */
787 	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
788 	case SND_SOC_DAIFMT_NB_NF:
789 		ssi->bckp_rise = false;
790 		ssi->lrckp_fsync_fall = false;
791 		break;
792 	case SND_SOC_DAIFMT_NB_IF:
793 		ssi->bckp_rise = false;
794 		ssi->lrckp_fsync_fall = true;
795 		break;
796 	case SND_SOC_DAIFMT_IB_NF:
797 		ssi->bckp_rise = true;
798 		ssi->lrckp_fsync_fall = false;
799 		break;
800 	case SND_SOC_DAIFMT_IB_IF:
801 		ssi->bckp_rise = true;
802 		ssi->lrckp_fsync_fall = true;
803 		break;
804 	default:
805 		return -EINVAL;
806 	}
807 
808 	/* only i2s support */
809 	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
810 	case SND_SOC_DAIFMT_I2S:
811 		break;
812 	default:
813 		dev_err(ssi->dev, "Only I2S mode is supported.\n");
814 		return -EINVAL;
815 	}
816 
817 	return 0;
818 }
819 
820 static int rz_ssi_dai_hw_params(struct snd_pcm_substream *substream,
821 				struct snd_pcm_hw_params *params,
822 				struct snd_soc_dai *dai)
823 {
824 	struct rz_ssi_priv *ssi = snd_soc_dai_get_drvdata(dai);
825 	unsigned int sample_bits = hw_param_interval(params,
826 					SNDRV_PCM_HW_PARAM_SAMPLE_BITS)->min;
827 	unsigned int channels = params_channels(params);
828 
829 	if (sample_bits != 16) {
830 		dev_err(ssi->dev, "Unsupported sample width: %d\n",
831 			sample_bits);
832 		return -EINVAL;
833 	}
834 
835 	if (channels != 2) {
836 		dev_err(ssi->dev, "Number of channels not matched: %d\n",
837 			channels);
838 		return -EINVAL;
839 	}
840 
841 	return rz_ssi_clk_setup(ssi, params_rate(params),
842 				params_channels(params));
843 }
844 
845 static const struct snd_soc_dai_ops rz_ssi_dai_ops = {
846 	.trigger	= rz_ssi_dai_trigger,
847 	.set_fmt	= rz_ssi_dai_set_fmt,
848 	.hw_params	= rz_ssi_dai_hw_params,
849 };
850 
851 static const struct snd_pcm_hardware rz_ssi_pcm_hardware = {
852 	.info			= SNDRV_PCM_INFO_INTERLEAVED	|
853 				  SNDRV_PCM_INFO_MMAP		|
854 				  SNDRV_PCM_INFO_MMAP_VALID,
855 	.buffer_bytes_max	= PREALLOC_BUFFER,
856 	.period_bytes_min	= 32,
857 	.period_bytes_max	= 8192,
858 	.channels_min		= SSI_CHAN_MIN,
859 	.channels_max		= SSI_CHAN_MAX,
860 	.periods_min		= 1,
861 	.periods_max		= 32,
862 	.fifo_size		= 32 * 2,
863 };
864 
865 static int rz_ssi_pcm_open(struct snd_soc_component *component,
866 			   struct snd_pcm_substream *substream)
867 {
868 	snd_soc_set_runtime_hwparams(substream, &rz_ssi_pcm_hardware);
869 
870 	return snd_pcm_hw_constraint_integer(substream->runtime,
871 					    SNDRV_PCM_HW_PARAM_PERIODS);
872 }
873 
874 static snd_pcm_uframes_t rz_ssi_pcm_pointer(struct snd_soc_component *component,
875 					    struct snd_pcm_substream *substream)
876 {
877 	struct snd_soc_dai *dai = rz_ssi_get_dai(substream);
878 	struct rz_ssi_priv *ssi = snd_soc_dai_get_drvdata(dai);
879 	struct rz_ssi_stream *strm = rz_ssi_stream_get(ssi, substream);
880 
881 	return strm->buffer_pos;
882 }
883 
884 static int rz_ssi_pcm_new(struct snd_soc_component *component,
885 			  struct snd_soc_pcm_runtime *rtd)
886 {
887 	snd_pcm_set_managed_buffer_all(rtd->pcm, SNDRV_DMA_TYPE_DEV,
888 				       rtd->card->snd_card->dev,
889 				       PREALLOC_BUFFER, PREALLOC_BUFFER_MAX);
890 	return 0;
891 }
892 
893 static struct snd_soc_dai_driver rz_ssi_soc_dai[] = {
894 	{
895 		.name			= "rz-ssi-dai",
896 		.playback = {
897 			.rates		= SSI_RATES,
898 			.formats	= SSI_FMTS,
899 			.channels_min	= SSI_CHAN_MIN,
900 			.channels_max	= SSI_CHAN_MAX,
901 		},
902 		.capture = {
903 			.rates		= SSI_RATES,
904 			.formats	= SSI_FMTS,
905 			.channels_min	= SSI_CHAN_MIN,
906 			.channels_max	= SSI_CHAN_MAX,
907 		},
908 		.ops = &rz_ssi_dai_ops,
909 	},
910 };
911 
912 static const struct snd_soc_component_driver rz_ssi_soc_component = {
913 	.name		= "rz-ssi",
914 	.open		= rz_ssi_pcm_open,
915 	.pointer	= rz_ssi_pcm_pointer,
916 	.pcm_construct	= rz_ssi_pcm_new,
917 };
918 
919 static int rz_ssi_probe(struct platform_device *pdev)
920 {
921 	struct rz_ssi_priv *ssi;
922 	struct clk *audio_clk;
923 	struct resource *res;
924 	int ret;
925 
926 	ssi = devm_kzalloc(&pdev->dev, sizeof(*ssi), GFP_KERNEL);
927 	if (!ssi)
928 		return -ENOMEM;
929 
930 	ssi->pdev = pdev;
931 	ssi->dev = &pdev->dev;
932 	ssi->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
933 	if (IS_ERR(ssi->base))
934 		return PTR_ERR(ssi->base);
935 
936 	ssi->phys = res->start;
937 	ssi->clk = devm_clk_get(&pdev->dev, "ssi");
938 	if (IS_ERR(ssi->clk))
939 		return PTR_ERR(ssi->clk);
940 
941 	ssi->sfr_clk = devm_clk_get(&pdev->dev, "ssi_sfr");
942 	if (IS_ERR(ssi->sfr_clk))
943 		return PTR_ERR(ssi->sfr_clk);
944 
945 	audio_clk = devm_clk_get(&pdev->dev, "audio_clk1");
946 	if (IS_ERR(audio_clk))
947 		return dev_err_probe(&pdev->dev, PTR_ERR(audio_clk),
948 				     "no audio clk1");
949 
950 	ssi->audio_clk_1 = clk_get_rate(audio_clk);
951 	audio_clk = devm_clk_get(&pdev->dev, "audio_clk2");
952 	if (IS_ERR(audio_clk))
953 		return dev_err_probe(&pdev->dev, PTR_ERR(audio_clk),
954 				     "no audio clk2");
955 
956 	ssi->audio_clk_2 = clk_get_rate(audio_clk);
957 	if (!(ssi->audio_clk_1 || ssi->audio_clk_2))
958 		return dev_err_probe(&pdev->dev, -EINVAL,
959 				     "no audio clk1 or audio clk2");
960 
961 	ssi->audio_mck = ssi->audio_clk_1 ? ssi->audio_clk_1 : ssi->audio_clk_2;
962 
963 	/* Detect DMA support */
964 	ret = rz_ssi_dma_request(ssi, &pdev->dev);
965 	if (ret < 0) {
966 		dev_warn(&pdev->dev, "DMA not available, using PIO\n");
967 		ssi->playback.transfer = rz_ssi_pio_send;
968 		ssi->capture.transfer = rz_ssi_pio_recv;
969 	} else {
970 		dev_info(&pdev->dev, "DMA enabled");
971 		ssi->playback.transfer = rz_ssi_dma_transfer;
972 		ssi->capture.transfer = rz_ssi_dma_transfer;
973 	}
974 
975 	ssi->playback.priv = ssi;
976 	ssi->capture.priv = ssi;
977 
978 	/* Error Interrupt */
979 	ssi->irq_int = platform_get_irq_byname(pdev, "int_req");
980 	if (ssi->irq_int < 0)
981 		return dev_err_probe(&pdev->dev, -ENODEV,
982 				     "Unable to get SSI int_req IRQ\n");
983 
984 	ret = devm_request_irq(&pdev->dev, ssi->irq_int, &rz_ssi_interrupt,
985 			       0, dev_name(&pdev->dev), ssi);
986 	if (ret < 0)
987 		return dev_err_probe(&pdev->dev, ret,
988 				     "irq request error (int_req)\n");
989 
990 	if (!rz_ssi_is_dma_enabled(ssi)) {
991 		/* Tx and Rx interrupts (pio only) */
992 		ssi->irq_tx = platform_get_irq_byname(pdev, "dma_tx");
993 		if (ssi->irq_tx < 0)
994 			return dev_err_probe(&pdev->dev, -ENODEV,
995 					     "Unable to get SSI dma_tx IRQ\n");
996 
997 		ret = devm_request_irq(&pdev->dev, ssi->irq_tx,
998 				       &rz_ssi_interrupt, 0,
999 				       dev_name(&pdev->dev), ssi);
1000 		if (ret < 0)
1001 			return dev_err_probe(&pdev->dev, ret,
1002 					     "irq request error (dma_tx)\n");
1003 
1004 		ssi->irq_rx = platform_get_irq_byname(pdev, "dma_rx");
1005 		if (ssi->irq_rx < 0)
1006 			return dev_err_probe(&pdev->dev, -ENODEV,
1007 					     "Unable to get SSI dma_rx IRQ\n");
1008 
1009 		ret = devm_request_irq(&pdev->dev, ssi->irq_rx,
1010 				       &rz_ssi_interrupt, 0,
1011 				       dev_name(&pdev->dev), ssi);
1012 		if (ret < 0)
1013 			return dev_err_probe(&pdev->dev, ret,
1014 					     "irq request error (dma_rx)\n");
1015 	}
1016 
1017 	ssi->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
1018 	if (IS_ERR(ssi->rstc))
1019 		return PTR_ERR(ssi->rstc);
1020 
1021 	reset_control_deassert(ssi->rstc);
1022 	pm_runtime_enable(&pdev->dev);
1023 	pm_runtime_resume_and_get(&pdev->dev);
1024 
1025 	spin_lock_init(&ssi->lock);
1026 	dev_set_drvdata(&pdev->dev, ssi);
1027 	ret = devm_snd_soc_register_component(&pdev->dev, &rz_ssi_soc_component,
1028 					      rz_ssi_soc_dai,
1029 					      ARRAY_SIZE(rz_ssi_soc_dai));
1030 	if (ret < 0) {
1031 		rz_ssi_release_dma_channels(ssi);
1032 
1033 		pm_runtime_put(ssi->dev);
1034 		pm_runtime_disable(ssi->dev);
1035 		reset_control_assert(ssi->rstc);
1036 		dev_err(&pdev->dev, "failed to register snd component\n");
1037 	}
1038 
1039 	return ret;
1040 }
1041 
1042 static int rz_ssi_remove(struct platform_device *pdev)
1043 {
1044 	struct rz_ssi_priv *ssi = dev_get_drvdata(&pdev->dev);
1045 
1046 	rz_ssi_release_dma_channels(ssi);
1047 
1048 	pm_runtime_put(ssi->dev);
1049 	pm_runtime_disable(ssi->dev);
1050 	reset_control_assert(ssi->rstc);
1051 
1052 	return 0;
1053 }
1054 
1055 static const struct of_device_id rz_ssi_of_match[] = {
1056 	{ .compatible = "renesas,rz-ssi", },
1057 	{/* Sentinel */},
1058 };
1059 MODULE_DEVICE_TABLE(of, rz_ssi_of_match);
1060 
1061 static struct platform_driver rz_ssi_driver = {
1062 	.driver	= {
1063 		.name	= "rz-ssi-pcm-audio",
1064 		.of_match_table = rz_ssi_of_match,
1065 	},
1066 	.probe		= rz_ssi_probe,
1067 	.remove		= rz_ssi_remove,
1068 };
1069 
1070 module_platform_driver(rz_ssi_driver);
1071 
1072 MODULE_LICENSE("GPL v2");
1073 MODULE_DESCRIPTION("Renesas RZ/G2L ASoC Serial Sound Interface Driver");
1074 MODULE_AUTHOR("Biju Das <biju.das.jz@bp.renesas.com>");
1075