xref: /openbmc/linux/sound/soc/sh/rz-ssi.c (revision e40573a4)
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 
32 #define SSICR_CKS		BIT(30)
33 #define SSICR_TUIEN		BIT(29)
34 #define SSICR_TOIEN		BIT(28)
35 #define SSICR_RUIEN		BIT(27)
36 #define SSICR_ROIEN		BIT(26)
37 #define SSICR_MST		BIT(14)
38 #define SSICR_BCKP		BIT(13)
39 #define SSICR_LRCKP		BIT(12)
40 #define SSICR_CKDV(x)		(((x) & 0xf) << 4)
41 #define SSICR_TEN		BIT(1)
42 #define SSICR_REN		BIT(0)
43 
44 #define SSISR_TUIRQ		BIT(29)
45 #define SSISR_TOIRQ		BIT(28)
46 #define SSISR_RUIRQ		BIT(27)
47 #define SSISR_ROIRQ		BIT(26)
48 #define SSISR_IIRQ		BIT(25)
49 
50 #define SSIFCR_AUCKE		BIT(31)
51 #define SSIFCR_SSIRST		BIT(16)
52 #define SSIFCR_TIE		BIT(3)
53 #define SSIFCR_RIE		BIT(2)
54 #define SSIFCR_TFRST		BIT(1)
55 #define SSIFCR_RFRST		BIT(0)
56 
57 #define SSIFSR_TDC_MASK		0x3f
58 #define SSIFSR_TDC_SHIFT	24
59 #define SSIFSR_RDC_MASK		0x3f
60 #define SSIFSR_RDC_SHIFT	8
61 
62 #define SSIFSR_TDE		BIT(16)
63 #define SSIFSR_RDF		BIT(0)
64 
65 #define SSIOFR_LRCONT		BIT(8)
66 
67 #define SSISCR_TDES(x)		(((x) & 0x1f) << 8)
68 #define SSISCR_RDFS(x)		(((x) & 0x1f) << 0)
69 
70 /* Pre allocated buffers sizes */
71 #define PREALLOC_BUFFER		(SZ_32K)
72 #define PREALLOC_BUFFER_MAX	(SZ_32K)
73 
74 #define SSI_RATES		SNDRV_PCM_RATE_8000_48000 /* 8k-44.1kHz */
75 #define SSI_FMTS		SNDRV_PCM_FMTBIT_S16_LE
76 #define SSI_CHAN_MIN		2
77 #define SSI_CHAN_MAX		2
78 #define SSI_FIFO_DEPTH		32
79 
80 struct rz_ssi_priv;
81 
82 struct rz_ssi_stream {
83 	struct rz_ssi_priv *priv;
84 	struct snd_pcm_substream *substream;
85 	int fifo_sample_size;	/* sample capacity of SSI FIFO */
86 	int dma_buffer_pos;	/* The address for the next DMA descriptor */
87 	int period_counter;	/* for keeping track of periods transferred */
88 	int sample_width;
89 	int buffer_pos;		/* current frame position in the buffer */
90 	int running;		/* 0=stopped, 1=running */
91 
92 	int uerr_num;
93 	int oerr_num;
94 
95 	struct dma_chan *dma_ch;
96 
97 	int (*transfer)(struct rz_ssi_priv *ssi, struct rz_ssi_stream *strm);
98 };
99 
100 struct rz_ssi_priv {
101 	void __iomem *base;
102 	struct platform_device *pdev;
103 	struct reset_control *rstc;
104 	struct device *dev;
105 	struct clk *sfr_clk;
106 	struct clk *clk;
107 
108 	phys_addr_t phys;
109 	int irq_int;
110 	int irq_tx;
111 	int irq_rx;
112 
113 	spinlock_t lock;
114 
115 	/*
116 	 * The SSI supports full-duplex transmission and reception.
117 	 * However, if an error occurs, channel reset (both transmission
118 	 * and reception reset) is required.
119 	 * So it is better to use as half-duplex (playing and recording
120 	 * should be done on separate channels).
121 	 */
122 	struct rz_ssi_stream playback;
123 	struct rz_ssi_stream capture;
124 
125 	/* clock */
126 	unsigned long audio_mck;
127 	unsigned long audio_clk_1;
128 	unsigned long audio_clk_2;
129 
130 	bool lrckp_fsync_fall;	/* LR clock polarity (SSICR.LRCKP) */
131 	bool bckp_rise;	/* Bit clock polarity (SSICR.BCKP) */
132 	bool dma_rt;
133 };
134 
135 static void rz_ssi_dma_complete(void *data);
136 
137 static void rz_ssi_reg_writel(struct rz_ssi_priv *priv, uint reg, u32 data)
138 {
139 	writel(data, (priv->base + reg));
140 }
141 
142 static u32 rz_ssi_reg_readl(struct rz_ssi_priv *priv, uint reg)
143 {
144 	return readl(priv->base + reg);
145 }
146 
147 static void rz_ssi_reg_mask_setl(struct rz_ssi_priv *priv, uint reg,
148 				 u32 bclr, u32 bset)
149 {
150 	u32 val;
151 
152 	val = readl(priv->base + reg);
153 	val = (val & ~bclr) | bset;
154 	writel(val, (priv->base + reg));
155 }
156 
157 static inline struct snd_soc_dai *
158 rz_ssi_get_dai(struct snd_pcm_substream *substream)
159 {
160 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
161 
162 	return asoc_rtd_to_cpu(rtd, 0);
163 }
164 
165 static inline bool rz_ssi_stream_is_play(struct rz_ssi_priv *ssi,
166 					 struct snd_pcm_substream *substream)
167 {
168 	return substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
169 }
170 
171 static inline struct rz_ssi_stream *
172 rz_ssi_stream_get(struct rz_ssi_priv *ssi, struct snd_pcm_substream *substream)
173 {
174 	struct rz_ssi_stream *stream = &ssi->playback;
175 
176 	if (substream->stream != SNDRV_PCM_STREAM_PLAYBACK)
177 		stream = &ssi->capture;
178 
179 	return stream;
180 }
181 
182 static inline bool rz_ssi_is_dma_enabled(struct rz_ssi_priv *ssi)
183 {
184 	return (ssi->playback.dma_ch && (ssi->dma_rt || ssi->capture.dma_ch));
185 }
186 
187 static void rz_ssi_set_substream(struct rz_ssi_stream *strm,
188 				 struct snd_pcm_substream *substream)
189 {
190 	struct rz_ssi_priv *ssi = strm->priv;
191 	unsigned long flags;
192 
193 	spin_lock_irqsave(&ssi->lock, flags);
194 	strm->substream = substream;
195 	spin_unlock_irqrestore(&ssi->lock, flags);
196 }
197 
198 static bool rz_ssi_stream_is_valid(struct rz_ssi_priv *ssi,
199 				   struct rz_ssi_stream *strm)
200 {
201 	unsigned long flags;
202 	bool ret;
203 
204 	spin_lock_irqsave(&ssi->lock, flags);
205 	ret = strm->substream && strm->substream->runtime;
206 	spin_unlock_irqrestore(&ssi->lock, flags);
207 
208 	return ret;
209 }
210 
211 static void rz_ssi_stream_init(struct rz_ssi_stream *strm,
212 			       struct snd_pcm_substream *substream)
213 {
214 	struct snd_pcm_runtime *runtime = substream->runtime;
215 
216 	rz_ssi_set_substream(strm, substream);
217 	strm->sample_width = samples_to_bytes(runtime, 1);
218 	strm->dma_buffer_pos = 0;
219 	strm->period_counter = 0;
220 	strm->buffer_pos = 0;
221 
222 	strm->oerr_num = 0;
223 	strm->uerr_num = 0;
224 	strm->running = 0;
225 
226 	/* fifo init */
227 	strm->fifo_sample_size = SSI_FIFO_DEPTH;
228 }
229 
230 static void rz_ssi_stream_quit(struct rz_ssi_priv *ssi,
231 			       struct rz_ssi_stream *strm)
232 {
233 	struct snd_soc_dai *dai = rz_ssi_get_dai(strm->substream);
234 
235 	rz_ssi_set_substream(strm, NULL);
236 
237 	if (strm->oerr_num > 0)
238 		dev_info(dai->dev, "overrun = %d\n", strm->oerr_num);
239 
240 	if (strm->uerr_num > 0)
241 		dev_info(dai->dev, "underrun = %d\n", strm->uerr_num);
242 }
243 
244 static int rz_ssi_clk_setup(struct rz_ssi_priv *ssi, unsigned int rate,
245 			    unsigned int channels)
246 {
247 	static s8 ckdv[16] = { 1,  2,  4,  8, 16, 32, 64, 128,
248 			       6, 12, 24, 48, 96, -1, -1, -1 };
249 	unsigned int channel_bits = 32;	/* System Word Length */
250 	unsigned long bclk_rate = rate * channels * channel_bits;
251 	unsigned int div;
252 	unsigned int i;
253 	u32 ssicr = 0;
254 	u32 clk_ckdv;
255 
256 	/* Clear AUCKE so we can set MST */
257 	rz_ssi_reg_writel(ssi, SSIFCR, 0);
258 
259 	/* Continue to output LRCK pin even when idle */
260 	rz_ssi_reg_writel(ssi, SSIOFR, SSIOFR_LRCONT);
261 	if (ssi->audio_clk_1 && ssi->audio_clk_2) {
262 		if (ssi->audio_clk_1 % bclk_rate)
263 			ssi->audio_mck = ssi->audio_clk_2;
264 		else
265 			ssi->audio_mck = ssi->audio_clk_1;
266 	}
267 
268 	/* Clock setting */
269 	ssicr |= SSICR_MST;
270 	if (ssi->audio_mck == ssi->audio_clk_1)
271 		ssicr |= SSICR_CKS;
272 	if (ssi->bckp_rise)
273 		ssicr |= SSICR_BCKP;
274 	if (ssi->lrckp_fsync_fall)
275 		ssicr |= SSICR_LRCKP;
276 
277 	/* Determine the clock divider */
278 	clk_ckdv = 0;
279 	div = ssi->audio_mck / bclk_rate;
280 	/* try to find an match */
281 	for (i = 0; i < ARRAY_SIZE(ckdv); i++) {
282 		if (ckdv[i] == div) {
283 			clk_ckdv = i;
284 			break;
285 		}
286 	}
287 
288 	if (i == ARRAY_SIZE(ckdv)) {
289 		dev_err(ssi->dev, "Rate not divisible by audio clock source\n");
290 		return -EINVAL;
291 	}
292 
293 	/*
294 	 * DWL: Data Word Length = 16 bits
295 	 * SWL: System Word Length = 32 bits
296 	 */
297 	ssicr |= SSICR_CKDV(clk_ckdv);
298 	ssicr |= SSICR_DWL(1) | SSICR_SWL(3);
299 	rz_ssi_reg_writel(ssi, SSICR, ssicr);
300 	rz_ssi_reg_writel(ssi, SSIFCR,
301 			  (SSIFCR_AUCKE | SSIFCR_TFRST | SSIFCR_RFRST));
302 
303 	return 0;
304 }
305 
306 static int rz_ssi_start(struct rz_ssi_priv *ssi, struct rz_ssi_stream *strm)
307 {
308 	bool is_play = rz_ssi_stream_is_play(ssi, strm->substream);
309 	u32 ssicr, ssifcr;
310 
311 	ssicr = rz_ssi_reg_readl(ssi, SSICR);
312 	ssifcr = rz_ssi_reg_readl(ssi, SSIFCR) & ~0xF;
313 
314 	/* FIFO interrupt thresholds */
315 	if (rz_ssi_is_dma_enabled(ssi))
316 		rz_ssi_reg_writel(ssi, SSISCR, 0);
317 	else
318 		rz_ssi_reg_writel(ssi, SSISCR,
319 				  SSISCR_TDES(strm->fifo_sample_size / 2 - 1) |
320 				  SSISCR_RDFS(0));
321 
322 	/* enable IRQ */
323 	if (is_play) {
324 		ssicr |= SSICR_TUIEN | SSICR_TOIEN;
325 		ssifcr |= SSIFCR_TIE | SSIFCR_RFRST;
326 	} else {
327 		ssicr |= SSICR_RUIEN | SSICR_ROIEN;
328 		ssifcr |= SSIFCR_RIE | SSIFCR_TFRST;
329 	}
330 
331 	rz_ssi_reg_writel(ssi, SSICR, ssicr);
332 	rz_ssi_reg_writel(ssi, SSIFCR, ssifcr);
333 
334 	/* Clear all error flags */
335 	rz_ssi_reg_mask_setl(ssi, SSISR,
336 			     (SSISR_TOIRQ | SSISR_TUIRQ | SSISR_ROIRQ |
337 			      SSISR_RUIRQ), 0);
338 
339 	strm->running = 1;
340 	ssicr |= is_play ? SSICR_TEN : SSICR_REN;
341 	rz_ssi_reg_writel(ssi, SSICR, ssicr);
342 
343 	return 0;
344 }
345 
346 static int rz_ssi_stop(struct rz_ssi_priv *ssi, struct rz_ssi_stream *strm)
347 {
348 	int timeout;
349 
350 	strm->running = 0;
351 
352 	/* Disable TX/RX */
353 	rz_ssi_reg_mask_setl(ssi, SSICR, SSICR_TEN | SSICR_REN, 0);
354 
355 	/* Cancel all remaining DMA transactions */
356 	if (rz_ssi_is_dma_enabled(ssi))
357 		dmaengine_terminate_async(strm->dma_ch);
358 
359 	/* Disable irqs */
360 	rz_ssi_reg_mask_setl(ssi, SSICR, SSICR_TUIEN | SSICR_TOIEN |
361 			     SSICR_RUIEN | SSICR_ROIEN, 0);
362 	rz_ssi_reg_mask_setl(ssi, SSIFCR, SSIFCR_TIE | SSIFCR_RIE, 0);
363 
364 	/* Clear all error flags */
365 	rz_ssi_reg_mask_setl(ssi, SSISR,
366 			     (SSISR_TOIRQ | SSISR_TUIRQ | SSISR_ROIRQ |
367 			      SSISR_RUIRQ), 0);
368 
369 	/* Wait for idle */
370 	timeout = 100;
371 	while (--timeout) {
372 		if (rz_ssi_reg_readl(ssi, SSISR) & SSISR_IIRQ)
373 			break;
374 		udelay(1);
375 	}
376 
377 	if (!timeout)
378 		dev_info(ssi->dev, "timeout waiting for SSI idle\n");
379 
380 	/* Hold FIFOs in reset */
381 	rz_ssi_reg_mask_setl(ssi, SSIFCR, 0,
382 			     SSIFCR_TFRST | SSIFCR_RFRST);
383 
384 	return 0;
385 }
386 
387 static void rz_ssi_pointer_update(struct rz_ssi_stream *strm, int frames)
388 {
389 	struct snd_pcm_substream *substream = strm->substream;
390 	struct snd_pcm_runtime *runtime;
391 	int current_period;
392 
393 	if (!strm->running || !substream || !substream->runtime)
394 		return;
395 
396 	runtime = substream->runtime;
397 	strm->buffer_pos += frames;
398 	WARN_ON(strm->buffer_pos > runtime->buffer_size);
399 
400 	/* ring buffer */
401 	if (strm->buffer_pos == runtime->buffer_size)
402 		strm->buffer_pos = 0;
403 
404 	current_period = strm->buffer_pos / runtime->period_size;
405 	if (strm->period_counter != current_period) {
406 		snd_pcm_period_elapsed(strm->substream);
407 		strm->period_counter = current_period;
408 	}
409 }
410 
411 static int rz_ssi_pio_recv(struct rz_ssi_priv *ssi, struct rz_ssi_stream *strm)
412 {
413 	struct snd_pcm_substream *substream = strm->substream;
414 	struct snd_pcm_runtime *runtime;
415 	u16 *buf;
416 	int fifo_samples;
417 	int frames_left;
418 	int samples;
419 	int i;
420 
421 	if (!rz_ssi_stream_is_valid(ssi, strm))
422 		return -EINVAL;
423 
424 	runtime = substream->runtime;
425 
426 	do {
427 		/* frames left in this period */
428 		frames_left = runtime->period_size -
429 			      (strm->buffer_pos % runtime->period_size);
430 		if (!frames_left)
431 			frames_left = runtime->period_size;
432 
433 		/* Samples in RX FIFO */
434 		fifo_samples = (rz_ssi_reg_readl(ssi, SSIFSR) >>
435 				SSIFSR_RDC_SHIFT) & SSIFSR_RDC_MASK;
436 
437 		/* Only read full frames at a time */
438 		samples = 0;
439 		while (frames_left && (fifo_samples >= runtime->channels)) {
440 			samples += runtime->channels;
441 			fifo_samples -= runtime->channels;
442 			frames_left--;
443 		}
444 
445 		/* not enough samples yet */
446 		if (!samples)
447 			break;
448 
449 		/* calculate new buffer index */
450 		buf = (u16 *)runtime->dma_area;
451 		buf += strm->buffer_pos * runtime->channels;
452 
453 		/* Note, only supports 16-bit samples */
454 		for (i = 0; i < samples; i++)
455 			*buf++ = (u16)(rz_ssi_reg_readl(ssi, SSIFRDR) >> 16);
456 
457 		rz_ssi_reg_mask_setl(ssi, SSIFSR, SSIFSR_RDF, 0);
458 		rz_ssi_pointer_update(strm, samples / runtime->channels);
459 	} while (!frames_left && fifo_samples >= runtime->channels);
460 
461 	return 0;
462 }
463 
464 static int rz_ssi_pio_send(struct rz_ssi_priv *ssi, struct rz_ssi_stream *strm)
465 {
466 	struct snd_pcm_substream *substream = strm->substream;
467 	struct snd_pcm_runtime *runtime = substream->runtime;
468 	int sample_space;
469 	int samples = 0;
470 	int frames_left;
471 	int i;
472 	u32 ssifsr;
473 	u16 *buf;
474 
475 	if (!rz_ssi_stream_is_valid(ssi, strm))
476 		return -EINVAL;
477 
478 	/* frames left in this period */
479 	frames_left = runtime->period_size - (strm->buffer_pos %
480 					      runtime->period_size);
481 	if (frames_left == 0)
482 		frames_left = runtime->period_size;
483 
484 	sample_space = strm->fifo_sample_size;
485 	ssifsr = rz_ssi_reg_readl(ssi, SSIFSR);
486 	sample_space -= (ssifsr >> SSIFSR_TDC_SHIFT) & SSIFSR_TDC_MASK;
487 
488 	/* Only add full frames at a time */
489 	while (frames_left && (sample_space >= runtime->channels)) {
490 		samples += runtime->channels;
491 		sample_space -= runtime->channels;
492 		frames_left--;
493 	}
494 
495 	/* no space to send anything right now */
496 	if (samples == 0)
497 		return 0;
498 
499 	/* calculate new buffer index */
500 	buf = (u16 *)(runtime->dma_area);
501 	buf += strm->buffer_pos * runtime->channels;
502 
503 	/* Note, only supports 16-bit samples */
504 	for (i = 0; i < samples; i++)
505 		rz_ssi_reg_writel(ssi, SSIFTDR, ((u32)(*buf++) << 16));
506 
507 	rz_ssi_reg_mask_setl(ssi, SSIFSR, SSIFSR_TDE, 0);
508 	rz_ssi_pointer_update(strm, samples / runtime->channels);
509 
510 	return 0;
511 }
512 
513 static irqreturn_t rz_ssi_interrupt(int irq, void *data)
514 {
515 	struct rz_ssi_stream *strm = NULL;
516 	struct rz_ssi_priv *ssi = data;
517 	u32 ssisr = rz_ssi_reg_readl(ssi, SSISR);
518 
519 	if (ssi->playback.substream)
520 		strm = &ssi->playback;
521 	else if (ssi->capture.substream)
522 		strm = &ssi->capture;
523 	else
524 		return IRQ_HANDLED; /* Left over TX/RX interrupt */
525 
526 	if (irq == ssi->irq_int) { /* error or idle */
527 		if (ssisr & SSISR_TUIRQ)
528 			strm->uerr_num++;
529 		if (ssisr & SSISR_TOIRQ)
530 			strm->oerr_num++;
531 		if (ssisr & SSISR_RUIRQ)
532 			strm->uerr_num++;
533 		if (ssisr & SSISR_ROIRQ)
534 			strm->oerr_num++;
535 
536 		if (ssisr & (SSISR_TUIRQ | SSISR_TOIRQ | SSISR_RUIRQ |
537 			     SSISR_ROIRQ)) {
538 			/* Error handling */
539 			/* You must reset (stop/restart) after each interrupt */
540 			rz_ssi_stop(ssi, strm);
541 
542 			/* Clear all flags */
543 			rz_ssi_reg_mask_setl(ssi, SSISR, SSISR_TOIRQ |
544 					     SSISR_TUIRQ | SSISR_ROIRQ |
545 					     SSISR_RUIRQ, 0);
546 
547 			/* Add/remove more data */
548 			strm->transfer(ssi, strm);
549 
550 			/* Resume */
551 			rz_ssi_start(ssi, strm);
552 		}
553 	}
554 
555 	if (!strm->running)
556 		return IRQ_HANDLED;
557 
558 	/* tx data empty */
559 	if (irq == ssi->irq_tx)
560 		strm->transfer(ssi, &ssi->playback);
561 
562 	/* rx data full */
563 	if (irq == ssi->irq_rx) {
564 		strm->transfer(ssi, &ssi->capture);
565 		rz_ssi_reg_mask_setl(ssi, SSIFSR, SSIFSR_RDF, 0);
566 	}
567 
568 	return IRQ_HANDLED;
569 }
570 
571 static int rz_ssi_dma_slave_config(struct rz_ssi_priv *ssi,
572 				   struct dma_chan *dma_ch, bool is_play)
573 {
574 	struct dma_slave_config cfg;
575 
576 	memset(&cfg, 0, sizeof(cfg));
577 
578 	cfg.direction = is_play ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
579 	cfg.dst_addr = ssi->phys + SSIFTDR;
580 	cfg.src_addr = ssi->phys + SSIFRDR;
581 	cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
582 	cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
583 
584 	return dmaengine_slave_config(dma_ch, &cfg);
585 }
586 
587 static int rz_ssi_dma_transfer(struct rz_ssi_priv *ssi,
588 			       struct rz_ssi_stream *strm)
589 {
590 	struct snd_pcm_substream *substream = strm->substream;
591 	struct dma_async_tx_descriptor *desc;
592 	struct snd_pcm_runtime *runtime;
593 	enum dma_transfer_direction dir;
594 	u32 dma_paddr, dma_size;
595 	int amount;
596 
597 	if (!rz_ssi_stream_is_valid(ssi, strm))
598 		return -EINVAL;
599 
600 	runtime = substream->runtime;
601 	if (runtime->status->state == SNDRV_PCM_STATE_DRAINING)
602 		/*
603 		 * Stream is ending, so do not queue up any more DMA
604 		 * transfers otherwise we play partial sound clips
605 		 * because we can't shut off the DMA quick enough.
606 		 */
607 		return 0;
608 
609 	dir = rz_ssi_stream_is_play(ssi, substream) ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
610 
611 	/* Always transfer 1 period */
612 	amount = runtime->period_size;
613 
614 	/* DMA physical address and size */
615 	dma_paddr = runtime->dma_addr + frames_to_bytes(runtime,
616 							strm->dma_buffer_pos);
617 	dma_size = frames_to_bytes(runtime, amount);
618 	desc = dmaengine_prep_slave_single(strm->dma_ch, dma_paddr, dma_size,
619 					   dir,
620 					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
621 	if (!desc) {
622 		dev_err(ssi->dev, "dmaengine_prep_slave_single() fail\n");
623 		return -ENOMEM;
624 	}
625 
626 	desc->callback = rz_ssi_dma_complete;
627 	desc->callback_param = strm;
628 
629 	if (dmaengine_submit(desc) < 0) {
630 		dev_err(ssi->dev, "dmaengine_submit() fail\n");
631 		return -EIO;
632 	}
633 
634 	/* Update DMA pointer */
635 	strm->dma_buffer_pos += amount;
636 	if (strm->dma_buffer_pos >= runtime->buffer_size)
637 		strm->dma_buffer_pos = 0;
638 
639 	/* Start DMA */
640 	dma_async_issue_pending(strm->dma_ch);
641 
642 	return 0;
643 }
644 
645 static void rz_ssi_dma_complete(void *data)
646 {
647 	struct rz_ssi_stream *strm = (struct rz_ssi_stream *)data;
648 
649 	if (!strm->running || !strm->substream || !strm->substream->runtime)
650 		return;
651 
652 	/* Note that next DMA transaction has probably already started */
653 	rz_ssi_pointer_update(strm, strm->substream->runtime->period_size);
654 
655 	/* Queue up another DMA transaction */
656 	rz_ssi_dma_transfer(strm->priv, strm);
657 }
658 
659 static void rz_ssi_release_dma_channels(struct rz_ssi_priv *ssi)
660 {
661 	if (ssi->playback.dma_ch) {
662 		dma_release_channel(ssi->playback.dma_ch);
663 		ssi->playback.dma_ch = NULL;
664 		if (ssi->dma_rt)
665 			ssi->dma_rt = false;
666 	}
667 
668 	if (ssi->capture.dma_ch) {
669 		dma_release_channel(ssi->capture.dma_ch);
670 		ssi->capture.dma_ch = NULL;
671 	}
672 }
673 
674 static int rz_ssi_dma_request(struct rz_ssi_priv *ssi, struct device *dev)
675 {
676 	ssi->playback.dma_ch = dma_request_chan(dev, "tx");
677 	if (IS_ERR(ssi->playback.dma_ch))
678 		ssi->playback.dma_ch = NULL;
679 
680 	ssi->capture.dma_ch = dma_request_chan(dev, "rx");
681 	if (IS_ERR(ssi->capture.dma_ch))
682 		ssi->capture.dma_ch = NULL;
683 
684 	if (!ssi->playback.dma_ch && !ssi->capture.dma_ch) {
685 		ssi->playback.dma_ch = dma_request_chan(dev, "rt");
686 		if (IS_ERR(ssi->playback.dma_ch)) {
687 			ssi->playback.dma_ch = NULL;
688 			goto no_dma;
689 		}
690 
691 		ssi->dma_rt = true;
692 	}
693 
694 	if (!rz_ssi_is_dma_enabled(ssi))
695 		goto no_dma;
696 
697 	if (ssi->playback.dma_ch &&
698 	    (rz_ssi_dma_slave_config(ssi, ssi->playback.dma_ch, true) < 0))
699 		goto no_dma;
700 
701 	if (ssi->capture.dma_ch &&
702 	    (rz_ssi_dma_slave_config(ssi, ssi->capture.dma_ch, false) < 0))
703 		goto no_dma;
704 
705 	return 0;
706 
707 no_dma:
708 	rz_ssi_release_dma_channels(ssi);
709 
710 	return -ENODEV;
711 }
712 
713 static int rz_ssi_dai_trigger(struct snd_pcm_substream *substream, int cmd,
714 			      struct snd_soc_dai *dai)
715 {
716 	struct rz_ssi_priv *ssi = snd_soc_dai_get_drvdata(dai);
717 	struct rz_ssi_stream *strm = rz_ssi_stream_get(ssi, substream);
718 	int ret = 0, i, num_transfer = 1;
719 
720 	switch (cmd) {
721 	case SNDRV_PCM_TRIGGER_START:
722 		/* Soft Reset */
723 		rz_ssi_reg_mask_setl(ssi, SSIFCR, 0, SSIFCR_SSIRST);
724 		rz_ssi_reg_mask_setl(ssi, SSIFCR, SSIFCR_SSIRST, 0);
725 		udelay(5);
726 
727 		rz_ssi_stream_init(strm, substream);
728 
729 		if (ssi->dma_rt) {
730 			bool is_playback;
731 
732 			is_playback = rz_ssi_stream_is_play(ssi, substream);
733 			ret = rz_ssi_dma_slave_config(ssi, ssi->playback.dma_ch,
734 						      is_playback);
735 			/* Fallback to pio */
736 			if (ret < 0) {
737 				ssi->playback.transfer = rz_ssi_pio_send;
738 				ssi->capture.transfer = rz_ssi_pio_recv;
739 				rz_ssi_release_dma_channels(ssi);
740 			}
741 		}
742 
743 		/* For DMA, queue up multiple DMA descriptors */
744 		if (rz_ssi_is_dma_enabled(ssi))
745 			num_transfer = 4;
746 
747 		for (i = 0; i < num_transfer; i++) {
748 			ret = strm->transfer(ssi, strm);
749 			if (ret)
750 				goto done;
751 		}
752 
753 		ret = rz_ssi_start(ssi, strm);
754 		break;
755 	case SNDRV_PCM_TRIGGER_STOP:
756 		rz_ssi_stop(ssi, strm);
757 		rz_ssi_stream_quit(ssi, strm);
758 		break;
759 	}
760 
761 done:
762 	return ret;
763 }
764 
765 static int rz_ssi_dai_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
766 {
767 	struct rz_ssi_priv *ssi = snd_soc_dai_get_drvdata(dai);
768 
769 	switch (fmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK) {
770 	case SND_SOC_DAIFMT_BP_FP:
771 		break;
772 	default:
773 		dev_err(ssi->dev, "Codec should be clk and frame consumer\n");
774 		return -EINVAL;
775 	}
776 
777 	/*
778 	 * set clock polarity
779 	 *
780 	 * "normal" BCLK = Signal is available at rising edge of BCLK
781 	 * "normal" FSYNC = (I2S) Left ch starts with falling FSYNC edge
782 	 */
783 	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
784 	case SND_SOC_DAIFMT_NB_NF:
785 		ssi->bckp_rise = false;
786 		ssi->lrckp_fsync_fall = false;
787 		break;
788 	case SND_SOC_DAIFMT_NB_IF:
789 		ssi->bckp_rise = false;
790 		ssi->lrckp_fsync_fall = true;
791 		break;
792 	case SND_SOC_DAIFMT_IB_NF:
793 		ssi->bckp_rise = true;
794 		ssi->lrckp_fsync_fall = false;
795 		break;
796 	case SND_SOC_DAIFMT_IB_IF:
797 		ssi->bckp_rise = true;
798 		ssi->lrckp_fsync_fall = true;
799 		break;
800 	default:
801 		return -EINVAL;
802 	}
803 
804 	/* only i2s support */
805 	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
806 	case SND_SOC_DAIFMT_I2S:
807 		break;
808 	default:
809 		dev_err(ssi->dev, "Only I2S mode is supported.\n");
810 		return -EINVAL;
811 	}
812 
813 	return 0;
814 }
815 
816 static int rz_ssi_dai_hw_params(struct snd_pcm_substream *substream,
817 				struct snd_pcm_hw_params *params,
818 				struct snd_soc_dai *dai)
819 {
820 	struct rz_ssi_priv *ssi = snd_soc_dai_get_drvdata(dai);
821 	unsigned int sample_bits = hw_param_interval(params,
822 					SNDRV_PCM_HW_PARAM_SAMPLE_BITS)->min;
823 	unsigned int channels = params_channels(params);
824 
825 	if (sample_bits != 16) {
826 		dev_err(ssi->dev, "Unsupported sample width: %d\n",
827 			sample_bits);
828 		return -EINVAL;
829 	}
830 
831 	if (channels != 2) {
832 		dev_err(ssi->dev, "Number of channels not matched: %d\n",
833 			channels);
834 		return -EINVAL;
835 	}
836 
837 	return rz_ssi_clk_setup(ssi, params_rate(params),
838 				params_channels(params));
839 }
840 
841 static const struct snd_soc_dai_ops rz_ssi_dai_ops = {
842 	.trigger	= rz_ssi_dai_trigger,
843 	.set_fmt	= rz_ssi_dai_set_fmt,
844 	.hw_params	= rz_ssi_dai_hw_params,
845 };
846 
847 static const struct snd_pcm_hardware rz_ssi_pcm_hardware = {
848 	.info			= SNDRV_PCM_INFO_INTERLEAVED	|
849 				  SNDRV_PCM_INFO_MMAP		|
850 				  SNDRV_PCM_INFO_MMAP_VALID,
851 	.buffer_bytes_max	= PREALLOC_BUFFER,
852 	.period_bytes_min	= 32,
853 	.period_bytes_max	= 8192,
854 	.channels_min		= SSI_CHAN_MIN,
855 	.channels_max		= SSI_CHAN_MAX,
856 	.periods_min		= 1,
857 	.periods_max		= 32,
858 	.fifo_size		= 32 * 2,
859 };
860 
861 static int rz_ssi_pcm_open(struct snd_soc_component *component,
862 			   struct snd_pcm_substream *substream)
863 {
864 	snd_soc_set_runtime_hwparams(substream, &rz_ssi_pcm_hardware);
865 
866 	return snd_pcm_hw_constraint_integer(substream->runtime,
867 					    SNDRV_PCM_HW_PARAM_PERIODS);
868 }
869 
870 static snd_pcm_uframes_t rz_ssi_pcm_pointer(struct snd_soc_component *component,
871 					    struct snd_pcm_substream *substream)
872 {
873 	struct snd_soc_dai *dai = rz_ssi_get_dai(substream);
874 	struct rz_ssi_priv *ssi = snd_soc_dai_get_drvdata(dai);
875 	struct rz_ssi_stream *strm = rz_ssi_stream_get(ssi, substream);
876 
877 	return strm->buffer_pos;
878 }
879 
880 static int rz_ssi_pcm_new(struct snd_soc_component *component,
881 			  struct snd_soc_pcm_runtime *rtd)
882 {
883 	snd_pcm_set_managed_buffer_all(rtd->pcm, SNDRV_DMA_TYPE_DEV,
884 				       rtd->card->snd_card->dev,
885 				       PREALLOC_BUFFER, PREALLOC_BUFFER_MAX);
886 	return 0;
887 }
888 
889 static struct snd_soc_dai_driver rz_ssi_soc_dai[] = {
890 	{
891 		.name			= "rz-ssi-dai",
892 		.playback = {
893 			.rates		= SSI_RATES,
894 			.formats	= SSI_FMTS,
895 			.channels_min	= SSI_CHAN_MIN,
896 			.channels_max	= SSI_CHAN_MAX,
897 		},
898 		.capture = {
899 			.rates		= SSI_RATES,
900 			.formats	= SSI_FMTS,
901 			.channels_min	= SSI_CHAN_MIN,
902 			.channels_max	= SSI_CHAN_MAX,
903 		},
904 		.ops = &rz_ssi_dai_ops,
905 	},
906 };
907 
908 static const struct snd_soc_component_driver rz_ssi_soc_component = {
909 	.name			= "rz-ssi",
910 	.open			= rz_ssi_pcm_open,
911 	.pointer		= rz_ssi_pcm_pointer,
912 	.pcm_construct		= rz_ssi_pcm_new,
913 	.legacy_dai_naming	= 1,
914 };
915 
916 static int rz_ssi_probe(struct platform_device *pdev)
917 {
918 	struct rz_ssi_priv *ssi;
919 	struct clk *audio_clk;
920 	struct resource *res;
921 	int ret;
922 
923 	ssi = devm_kzalloc(&pdev->dev, sizeof(*ssi), GFP_KERNEL);
924 	if (!ssi)
925 		return -ENOMEM;
926 
927 	ssi->pdev = pdev;
928 	ssi->dev = &pdev->dev;
929 	ssi->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
930 	if (IS_ERR(ssi->base))
931 		return PTR_ERR(ssi->base);
932 
933 	ssi->phys = res->start;
934 	ssi->clk = devm_clk_get(&pdev->dev, "ssi");
935 	if (IS_ERR(ssi->clk))
936 		return PTR_ERR(ssi->clk);
937 
938 	ssi->sfr_clk = devm_clk_get(&pdev->dev, "ssi_sfr");
939 	if (IS_ERR(ssi->sfr_clk))
940 		return PTR_ERR(ssi->sfr_clk);
941 
942 	audio_clk = devm_clk_get(&pdev->dev, "audio_clk1");
943 	if (IS_ERR(audio_clk))
944 		return dev_err_probe(&pdev->dev, PTR_ERR(audio_clk),
945 				     "no audio clk1");
946 
947 	ssi->audio_clk_1 = clk_get_rate(audio_clk);
948 	audio_clk = devm_clk_get(&pdev->dev, "audio_clk2");
949 	if (IS_ERR(audio_clk))
950 		return dev_err_probe(&pdev->dev, PTR_ERR(audio_clk),
951 				     "no audio clk2");
952 
953 	ssi->audio_clk_2 = clk_get_rate(audio_clk);
954 	if (!(ssi->audio_clk_1 || ssi->audio_clk_2))
955 		return dev_err_probe(&pdev->dev, -EINVAL,
956 				     "no audio clk1 or audio clk2");
957 
958 	ssi->audio_mck = ssi->audio_clk_1 ? ssi->audio_clk_1 : ssi->audio_clk_2;
959 
960 	/* Detect DMA support */
961 	ret = rz_ssi_dma_request(ssi, &pdev->dev);
962 	if (ret < 0) {
963 		dev_warn(&pdev->dev, "DMA not available, using PIO\n");
964 		ssi->playback.transfer = rz_ssi_pio_send;
965 		ssi->capture.transfer = rz_ssi_pio_recv;
966 	} else {
967 		dev_info(&pdev->dev, "DMA enabled");
968 		ssi->playback.transfer = rz_ssi_dma_transfer;
969 		ssi->capture.transfer = rz_ssi_dma_transfer;
970 	}
971 
972 	ssi->playback.priv = ssi;
973 	ssi->capture.priv = ssi;
974 
975 	spin_lock_init(&ssi->lock);
976 	dev_set_drvdata(&pdev->dev, ssi);
977 
978 	/* Error Interrupt */
979 	ssi->irq_int = platform_get_irq_byname(pdev, "int_req");
980 	if (ssi->irq_int < 0) {
981 		rz_ssi_release_dma_channels(ssi);
982 		return ssi->irq_int;
983 	}
984 
985 	ret = devm_request_irq(&pdev->dev, ssi->irq_int, &rz_ssi_interrupt,
986 			       0, dev_name(&pdev->dev), ssi);
987 	if (ret < 0) {
988 		rz_ssi_release_dma_channels(ssi);
989 		return dev_err_probe(&pdev->dev, ret,
990 				     "irq request error (int_req)\n");
991 	}
992 
993 	if (!rz_ssi_is_dma_enabled(ssi)) {
994 		/* Tx and Rx interrupts (pio only) */
995 		ssi->irq_tx = platform_get_irq_byname(pdev, "dma_tx");
996 		if (ssi->irq_tx < 0)
997 			return ssi->irq_tx;
998 
999 		ret = devm_request_irq(&pdev->dev, ssi->irq_tx,
1000 				       &rz_ssi_interrupt, 0,
1001 				       dev_name(&pdev->dev), ssi);
1002 		if (ret < 0)
1003 			return dev_err_probe(&pdev->dev, ret,
1004 					     "irq request error (dma_tx)\n");
1005 
1006 		ssi->irq_rx = platform_get_irq_byname(pdev, "dma_rx");
1007 		if (ssi->irq_rx < 0)
1008 			return ssi->irq_rx;
1009 
1010 		ret = devm_request_irq(&pdev->dev, ssi->irq_rx,
1011 				       &rz_ssi_interrupt, 0,
1012 				       dev_name(&pdev->dev), ssi);
1013 		if (ret < 0)
1014 			return dev_err_probe(&pdev->dev, ret,
1015 					     "irq request error (dma_rx)\n");
1016 	}
1017 
1018 	ssi->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
1019 	if (IS_ERR(ssi->rstc)) {
1020 		rz_ssi_release_dma_channels(ssi);
1021 		return PTR_ERR(ssi->rstc);
1022 	}
1023 
1024 	reset_control_deassert(ssi->rstc);
1025 	pm_runtime_enable(&pdev->dev);
1026 	ret = pm_runtime_resume_and_get(&pdev->dev);
1027 	if (ret < 0) {
1028 		rz_ssi_release_dma_channels(ssi);
1029 		pm_runtime_disable(ssi->dev);
1030 		reset_control_assert(ssi->rstc);
1031 		return dev_err_probe(ssi->dev, ret, "pm_runtime_resume_and_get failed\n");
1032 	}
1033 
1034 	ret = devm_snd_soc_register_component(&pdev->dev, &rz_ssi_soc_component,
1035 					      rz_ssi_soc_dai,
1036 					      ARRAY_SIZE(rz_ssi_soc_dai));
1037 	if (ret < 0) {
1038 		rz_ssi_release_dma_channels(ssi);
1039 
1040 		pm_runtime_put(ssi->dev);
1041 		pm_runtime_disable(ssi->dev);
1042 		reset_control_assert(ssi->rstc);
1043 		dev_err(&pdev->dev, "failed to register snd component\n");
1044 	}
1045 
1046 	return ret;
1047 }
1048 
1049 static int rz_ssi_remove(struct platform_device *pdev)
1050 {
1051 	struct rz_ssi_priv *ssi = dev_get_drvdata(&pdev->dev);
1052 
1053 	rz_ssi_release_dma_channels(ssi);
1054 
1055 	pm_runtime_put(ssi->dev);
1056 	pm_runtime_disable(ssi->dev);
1057 	reset_control_assert(ssi->rstc);
1058 
1059 	return 0;
1060 }
1061 
1062 static const struct of_device_id rz_ssi_of_match[] = {
1063 	{ .compatible = "renesas,rz-ssi", },
1064 	{/* Sentinel */},
1065 };
1066 MODULE_DEVICE_TABLE(of, rz_ssi_of_match);
1067 
1068 static struct platform_driver rz_ssi_driver = {
1069 	.driver	= {
1070 		.name	= "rz-ssi-pcm-audio",
1071 		.of_match_table = rz_ssi_of_match,
1072 	},
1073 	.probe		= rz_ssi_probe,
1074 	.remove		= rz_ssi_remove,
1075 };
1076 
1077 module_platform_driver(rz_ssi_driver);
1078 
1079 MODULE_LICENSE("GPL v2");
1080 MODULE_DESCRIPTION("Renesas RZ/G2L ASoC Serial Sound Interface Driver");
1081 MODULE_AUTHOR("Biju Das <biju.das.jz@bp.renesas.com>");
1082