xref: /openbmc/linux/sound/soc/sh/rz-ssi.c (revision d37cf9b63113f13d742713881ce691fc615d8b3b)
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 	int irq_rt;
113 
114 	spinlock_t lock;
115 
116 	/*
117 	 * The SSI supports full-duplex transmission and reception.
118 	 * However, if an error occurs, channel reset (both transmission
119 	 * and reception reset) is required.
120 	 * So it is better to use as half-duplex (playing and recording
121 	 * should be done on separate channels).
122 	 */
123 	struct rz_ssi_stream playback;
124 	struct rz_ssi_stream capture;
125 
126 	/* clock */
127 	unsigned long audio_mck;
128 	unsigned long audio_clk_1;
129 	unsigned long audio_clk_2;
130 
131 	bool lrckp_fsync_fall;	/* LR clock polarity (SSICR.LRCKP) */
132 	bool bckp_rise;	/* Bit clock polarity (SSICR.BCKP) */
133 	bool dma_rt;
134 };
135 
136 static void rz_ssi_dma_complete(void *data);
137 
rz_ssi_reg_writel(struct rz_ssi_priv * priv,uint reg,u32 data)138 static void rz_ssi_reg_writel(struct rz_ssi_priv *priv, uint reg, u32 data)
139 {
140 	writel(data, (priv->base + reg));
141 }
142 
rz_ssi_reg_readl(struct rz_ssi_priv * priv,uint reg)143 static u32 rz_ssi_reg_readl(struct rz_ssi_priv *priv, uint reg)
144 {
145 	return readl(priv->base + reg);
146 }
147 
rz_ssi_reg_mask_setl(struct rz_ssi_priv * priv,uint reg,u32 bclr,u32 bset)148 static void rz_ssi_reg_mask_setl(struct rz_ssi_priv *priv, uint reg,
149 				 u32 bclr, u32 bset)
150 {
151 	u32 val;
152 
153 	val = readl(priv->base + reg);
154 	val = (val & ~bclr) | bset;
155 	writel(val, (priv->base + reg));
156 }
157 
158 static inline struct snd_soc_dai *
rz_ssi_get_dai(struct snd_pcm_substream * substream)159 rz_ssi_get_dai(struct snd_pcm_substream *substream)
160 {
161 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
162 
163 	return asoc_rtd_to_cpu(rtd, 0);
164 }
165 
rz_ssi_stream_is_play(struct rz_ssi_priv * ssi,struct snd_pcm_substream * substream)166 static inline bool rz_ssi_stream_is_play(struct rz_ssi_priv *ssi,
167 					 struct snd_pcm_substream *substream)
168 {
169 	return substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
170 }
171 
172 static inline struct rz_ssi_stream *
rz_ssi_stream_get(struct rz_ssi_priv * ssi,struct snd_pcm_substream * substream)173 rz_ssi_stream_get(struct rz_ssi_priv *ssi, struct snd_pcm_substream *substream)
174 {
175 	struct rz_ssi_stream *stream = &ssi->playback;
176 
177 	if (substream->stream != SNDRV_PCM_STREAM_PLAYBACK)
178 		stream = &ssi->capture;
179 
180 	return stream;
181 }
182 
rz_ssi_is_dma_enabled(struct rz_ssi_priv * ssi)183 static inline bool rz_ssi_is_dma_enabled(struct rz_ssi_priv *ssi)
184 {
185 	return (ssi->playback.dma_ch && (ssi->dma_rt || ssi->capture.dma_ch));
186 }
187 
rz_ssi_set_substream(struct rz_ssi_stream * strm,struct snd_pcm_substream * substream)188 static void rz_ssi_set_substream(struct rz_ssi_stream *strm,
189 				 struct snd_pcm_substream *substream)
190 {
191 	struct rz_ssi_priv *ssi = strm->priv;
192 	unsigned long flags;
193 
194 	spin_lock_irqsave(&ssi->lock, flags);
195 	strm->substream = substream;
196 	spin_unlock_irqrestore(&ssi->lock, flags);
197 }
198 
rz_ssi_stream_is_valid(struct rz_ssi_priv * ssi,struct rz_ssi_stream * strm)199 static bool rz_ssi_stream_is_valid(struct rz_ssi_priv *ssi,
200 				   struct rz_ssi_stream *strm)
201 {
202 	unsigned long flags;
203 	bool ret;
204 
205 	spin_lock_irqsave(&ssi->lock, flags);
206 	ret = strm->substream && strm->substream->runtime;
207 	spin_unlock_irqrestore(&ssi->lock, flags);
208 
209 	return ret;
210 }
211 
rz_ssi_stream_init(struct rz_ssi_stream * strm,struct snd_pcm_substream * substream)212 static void rz_ssi_stream_init(struct rz_ssi_stream *strm,
213 			       struct snd_pcm_substream *substream)
214 {
215 	struct snd_pcm_runtime *runtime = substream->runtime;
216 
217 	rz_ssi_set_substream(strm, substream);
218 	strm->sample_width = samples_to_bytes(runtime, 1);
219 	strm->dma_buffer_pos = 0;
220 	strm->period_counter = 0;
221 	strm->buffer_pos = 0;
222 
223 	strm->oerr_num = 0;
224 	strm->uerr_num = 0;
225 	strm->running = 0;
226 
227 	/* fifo init */
228 	strm->fifo_sample_size = SSI_FIFO_DEPTH;
229 }
230 
rz_ssi_stream_quit(struct rz_ssi_priv * ssi,struct rz_ssi_stream * strm)231 static void rz_ssi_stream_quit(struct rz_ssi_priv *ssi,
232 			       struct rz_ssi_stream *strm)
233 {
234 	struct snd_soc_dai *dai = rz_ssi_get_dai(strm->substream);
235 
236 	rz_ssi_set_substream(strm, NULL);
237 
238 	if (strm->oerr_num > 0)
239 		dev_info(dai->dev, "overrun = %d\n", strm->oerr_num);
240 
241 	if (strm->uerr_num > 0)
242 		dev_info(dai->dev, "underrun = %d\n", strm->uerr_num);
243 }
244 
rz_ssi_clk_setup(struct rz_ssi_priv * ssi,unsigned int rate,unsigned int channels)245 static int rz_ssi_clk_setup(struct rz_ssi_priv *ssi, unsigned int rate,
246 			    unsigned int channels)
247 {
248 	static u8 ckdv[] = { 1,  2,  4,  8, 16, 32, 64, 128, 6, 12, 24, 48, 96 };
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 
rz_ssi_start(struct rz_ssi_priv * ssi,struct rz_ssi_stream * strm)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 
rz_ssi_stop(struct rz_ssi_priv * ssi,struct rz_ssi_stream * strm)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 
rz_ssi_pointer_update(struct rz_ssi_stream * strm,int frames)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 
rz_ssi_pio_recv(struct rz_ssi_priv * ssi,struct rz_ssi_stream * strm)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 
rz_ssi_pio_send(struct rz_ssi_priv * ssi,struct rz_ssi_stream * strm)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 	if (sample_space < 0)
488 		return -EINVAL;
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 
rz_ssi_interrupt(int irq,void * data)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 	if (irq == ssi->irq_rt) {
571 		struct snd_pcm_substream *substream = strm->substream;
572 
573 		if (rz_ssi_stream_is_play(ssi, substream)) {
574 			strm->transfer(ssi, &ssi->playback);
575 		} else {
576 			strm->transfer(ssi, &ssi->capture);
577 			rz_ssi_reg_mask_setl(ssi, SSIFSR, SSIFSR_RDF, 0);
578 		}
579 	}
580 
581 	return IRQ_HANDLED;
582 }
583 
rz_ssi_dma_slave_config(struct rz_ssi_priv * ssi,struct dma_chan * dma_ch,bool is_play)584 static int rz_ssi_dma_slave_config(struct rz_ssi_priv *ssi,
585 				   struct dma_chan *dma_ch, bool is_play)
586 {
587 	struct dma_slave_config cfg;
588 
589 	memset(&cfg, 0, sizeof(cfg));
590 
591 	cfg.direction = is_play ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
592 	cfg.dst_addr = ssi->phys + SSIFTDR;
593 	cfg.src_addr = ssi->phys + SSIFRDR;
594 	cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
595 	cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
596 
597 	return dmaengine_slave_config(dma_ch, &cfg);
598 }
599 
rz_ssi_dma_transfer(struct rz_ssi_priv * ssi,struct rz_ssi_stream * strm)600 static int rz_ssi_dma_transfer(struct rz_ssi_priv *ssi,
601 			       struct rz_ssi_stream *strm)
602 {
603 	struct snd_pcm_substream *substream = strm->substream;
604 	struct dma_async_tx_descriptor *desc;
605 	struct snd_pcm_runtime *runtime;
606 	enum dma_transfer_direction dir;
607 	u32 dma_paddr, dma_size;
608 	int amount;
609 
610 	if (!rz_ssi_stream_is_valid(ssi, strm))
611 		return -EINVAL;
612 
613 	runtime = substream->runtime;
614 	if (runtime->state == SNDRV_PCM_STATE_DRAINING)
615 		/*
616 		 * Stream is ending, so do not queue up any more DMA
617 		 * transfers otherwise we play partial sound clips
618 		 * because we can't shut off the DMA quick enough.
619 		 */
620 		return 0;
621 
622 	dir = rz_ssi_stream_is_play(ssi, substream) ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
623 
624 	/* Always transfer 1 period */
625 	amount = runtime->period_size;
626 
627 	/* DMA physical address and size */
628 	dma_paddr = runtime->dma_addr + frames_to_bytes(runtime,
629 							strm->dma_buffer_pos);
630 	dma_size = frames_to_bytes(runtime, amount);
631 	desc = dmaengine_prep_slave_single(strm->dma_ch, dma_paddr, dma_size,
632 					   dir,
633 					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
634 	if (!desc) {
635 		dev_err(ssi->dev, "dmaengine_prep_slave_single() fail\n");
636 		return -ENOMEM;
637 	}
638 
639 	desc->callback = rz_ssi_dma_complete;
640 	desc->callback_param = strm;
641 
642 	if (dmaengine_submit(desc) < 0) {
643 		dev_err(ssi->dev, "dmaengine_submit() fail\n");
644 		return -EIO;
645 	}
646 
647 	/* Update DMA pointer */
648 	strm->dma_buffer_pos += amount;
649 	if (strm->dma_buffer_pos >= runtime->buffer_size)
650 		strm->dma_buffer_pos = 0;
651 
652 	/* Start DMA */
653 	dma_async_issue_pending(strm->dma_ch);
654 
655 	return 0;
656 }
657 
rz_ssi_dma_complete(void * data)658 static void rz_ssi_dma_complete(void *data)
659 {
660 	struct rz_ssi_stream *strm = (struct rz_ssi_stream *)data;
661 
662 	if (!strm->running || !strm->substream || !strm->substream->runtime)
663 		return;
664 
665 	/* Note that next DMA transaction has probably already started */
666 	rz_ssi_pointer_update(strm, strm->substream->runtime->period_size);
667 
668 	/* Queue up another DMA transaction */
669 	rz_ssi_dma_transfer(strm->priv, strm);
670 }
671 
rz_ssi_release_dma_channels(struct rz_ssi_priv * ssi)672 static void rz_ssi_release_dma_channels(struct rz_ssi_priv *ssi)
673 {
674 	if (ssi->playback.dma_ch) {
675 		dma_release_channel(ssi->playback.dma_ch);
676 		ssi->playback.dma_ch = NULL;
677 		if (ssi->dma_rt)
678 			ssi->dma_rt = false;
679 	}
680 
681 	if (ssi->capture.dma_ch) {
682 		dma_release_channel(ssi->capture.dma_ch);
683 		ssi->capture.dma_ch = NULL;
684 	}
685 }
686 
rz_ssi_dma_request(struct rz_ssi_priv * ssi,struct device * dev)687 static int rz_ssi_dma_request(struct rz_ssi_priv *ssi, struct device *dev)
688 {
689 	ssi->playback.dma_ch = dma_request_chan(dev, "tx");
690 	if (IS_ERR(ssi->playback.dma_ch))
691 		ssi->playback.dma_ch = NULL;
692 
693 	ssi->capture.dma_ch = dma_request_chan(dev, "rx");
694 	if (IS_ERR(ssi->capture.dma_ch))
695 		ssi->capture.dma_ch = NULL;
696 
697 	if (!ssi->playback.dma_ch && !ssi->capture.dma_ch) {
698 		ssi->playback.dma_ch = dma_request_chan(dev, "rt");
699 		if (IS_ERR(ssi->playback.dma_ch)) {
700 			ssi->playback.dma_ch = NULL;
701 			goto no_dma;
702 		}
703 
704 		ssi->dma_rt = true;
705 	}
706 
707 	if (!rz_ssi_is_dma_enabled(ssi))
708 		goto no_dma;
709 
710 	if (ssi->playback.dma_ch &&
711 	    (rz_ssi_dma_slave_config(ssi, ssi->playback.dma_ch, true) < 0))
712 		goto no_dma;
713 
714 	if (ssi->capture.dma_ch &&
715 	    (rz_ssi_dma_slave_config(ssi, ssi->capture.dma_ch, false) < 0))
716 		goto no_dma;
717 
718 	return 0;
719 
720 no_dma:
721 	rz_ssi_release_dma_channels(ssi);
722 
723 	return -ENODEV;
724 }
725 
rz_ssi_dai_trigger(struct snd_pcm_substream * substream,int cmd,struct snd_soc_dai * dai)726 static int rz_ssi_dai_trigger(struct snd_pcm_substream *substream, int cmd,
727 			      struct snd_soc_dai *dai)
728 {
729 	struct rz_ssi_priv *ssi = snd_soc_dai_get_drvdata(dai);
730 	struct rz_ssi_stream *strm = rz_ssi_stream_get(ssi, substream);
731 	int ret = 0, i, num_transfer = 1;
732 
733 	switch (cmd) {
734 	case SNDRV_PCM_TRIGGER_START:
735 		/* Soft Reset */
736 		rz_ssi_reg_mask_setl(ssi, SSIFCR, 0, SSIFCR_SSIRST);
737 		rz_ssi_reg_mask_setl(ssi, SSIFCR, SSIFCR_SSIRST, 0);
738 		udelay(5);
739 
740 		rz_ssi_stream_init(strm, substream);
741 
742 		if (ssi->dma_rt) {
743 			bool is_playback;
744 
745 			is_playback = rz_ssi_stream_is_play(ssi, substream);
746 			ret = rz_ssi_dma_slave_config(ssi, ssi->playback.dma_ch,
747 						      is_playback);
748 			/* Fallback to pio */
749 			if (ret < 0) {
750 				ssi->playback.transfer = rz_ssi_pio_send;
751 				ssi->capture.transfer = rz_ssi_pio_recv;
752 				rz_ssi_release_dma_channels(ssi);
753 			}
754 		}
755 
756 		/* For DMA, queue up multiple DMA descriptors */
757 		if (rz_ssi_is_dma_enabled(ssi))
758 			num_transfer = 4;
759 
760 		for (i = 0; i < num_transfer; i++) {
761 			ret = strm->transfer(ssi, strm);
762 			if (ret)
763 				goto done;
764 		}
765 
766 		ret = rz_ssi_start(ssi, strm);
767 		break;
768 	case SNDRV_PCM_TRIGGER_STOP:
769 		rz_ssi_stop(ssi, strm);
770 		rz_ssi_stream_quit(ssi, strm);
771 		break;
772 	}
773 
774 done:
775 	return ret;
776 }
777 
rz_ssi_dai_set_fmt(struct snd_soc_dai * dai,unsigned int fmt)778 static int rz_ssi_dai_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
779 {
780 	struct rz_ssi_priv *ssi = snd_soc_dai_get_drvdata(dai);
781 
782 	switch (fmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK) {
783 	case SND_SOC_DAIFMT_BP_FP:
784 		break;
785 	default:
786 		dev_err(ssi->dev, "Codec should be clk and frame consumer\n");
787 		return -EINVAL;
788 	}
789 
790 	/*
791 	 * set clock polarity
792 	 *
793 	 * "normal" BCLK = Signal is available at rising edge of BCLK
794 	 * "normal" FSYNC = (I2S) Left ch starts with falling FSYNC edge
795 	 */
796 	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
797 	case SND_SOC_DAIFMT_NB_NF:
798 		ssi->bckp_rise = false;
799 		ssi->lrckp_fsync_fall = false;
800 		break;
801 	case SND_SOC_DAIFMT_NB_IF:
802 		ssi->bckp_rise = false;
803 		ssi->lrckp_fsync_fall = true;
804 		break;
805 	case SND_SOC_DAIFMT_IB_NF:
806 		ssi->bckp_rise = true;
807 		ssi->lrckp_fsync_fall = false;
808 		break;
809 	case SND_SOC_DAIFMT_IB_IF:
810 		ssi->bckp_rise = true;
811 		ssi->lrckp_fsync_fall = true;
812 		break;
813 	default:
814 		return -EINVAL;
815 	}
816 
817 	/* only i2s support */
818 	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
819 	case SND_SOC_DAIFMT_I2S:
820 		break;
821 	default:
822 		dev_err(ssi->dev, "Only I2S mode is supported.\n");
823 		return -EINVAL;
824 	}
825 
826 	return 0;
827 }
828 
rz_ssi_dai_hw_params(struct snd_pcm_substream * substream,struct snd_pcm_hw_params * params,struct snd_soc_dai * dai)829 static int rz_ssi_dai_hw_params(struct snd_pcm_substream *substream,
830 				struct snd_pcm_hw_params *params,
831 				struct snd_soc_dai *dai)
832 {
833 	struct rz_ssi_priv *ssi = snd_soc_dai_get_drvdata(dai);
834 	unsigned int sample_bits = hw_param_interval(params,
835 					SNDRV_PCM_HW_PARAM_SAMPLE_BITS)->min;
836 	unsigned int channels = params_channels(params);
837 
838 	if (sample_bits != 16) {
839 		dev_err(ssi->dev, "Unsupported sample width: %d\n",
840 			sample_bits);
841 		return -EINVAL;
842 	}
843 
844 	if (channels != 2) {
845 		dev_err(ssi->dev, "Number of channels not matched: %d\n",
846 			channels);
847 		return -EINVAL;
848 	}
849 
850 	return rz_ssi_clk_setup(ssi, params_rate(params),
851 				params_channels(params));
852 }
853 
854 static const struct snd_soc_dai_ops rz_ssi_dai_ops = {
855 	.trigger	= rz_ssi_dai_trigger,
856 	.set_fmt	= rz_ssi_dai_set_fmt,
857 	.hw_params	= rz_ssi_dai_hw_params,
858 };
859 
860 static const struct snd_pcm_hardware rz_ssi_pcm_hardware = {
861 	.info			= SNDRV_PCM_INFO_INTERLEAVED	|
862 				  SNDRV_PCM_INFO_MMAP		|
863 				  SNDRV_PCM_INFO_MMAP_VALID,
864 	.buffer_bytes_max	= PREALLOC_BUFFER,
865 	.period_bytes_min	= 32,
866 	.period_bytes_max	= 8192,
867 	.channels_min		= SSI_CHAN_MIN,
868 	.channels_max		= SSI_CHAN_MAX,
869 	.periods_min		= 1,
870 	.periods_max		= 32,
871 	.fifo_size		= 32 * 2,
872 };
873 
rz_ssi_pcm_open(struct snd_soc_component * component,struct snd_pcm_substream * substream)874 static int rz_ssi_pcm_open(struct snd_soc_component *component,
875 			   struct snd_pcm_substream *substream)
876 {
877 	snd_soc_set_runtime_hwparams(substream, &rz_ssi_pcm_hardware);
878 
879 	return snd_pcm_hw_constraint_integer(substream->runtime,
880 					    SNDRV_PCM_HW_PARAM_PERIODS);
881 }
882 
rz_ssi_pcm_pointer(struct snd_soc_component * component,struct snd_pcm_substream * substream)883 static snd_pcm_uframes_t rz_ssi_pcm_pointer(struct snd_soc_component *component,
884 					    struct snd_pcm_substream *substream)
885 {
886 	struct snd_soc_dai *dai = rz_ssi_get_dai(substream);
887 	struct rz_ssi_priv *ssi = snd_soc_dai_get_drvdata(dai);
888 	struct rz_ssi_stream *strm = rz_ssi_stream_get(ssi, substream);
889 
890 	return strm->buffer_pos;
891 }
892 
rz_ssi_pcm_new(struct snd_soc_component * component,struct snd_soc_pcm_runtime * rtd)893 static int rz_ssi_pcm_new(struct snd_soc_component *component,
894 			  struct snd_soc_pcm_runtime *rtd)
895 {
896 	snd_pcm_set_managed_buffer_all(rtd->pcm, SNDRV_DMA_TYPE_DEV,
897 				       rtd->card->snd_card->dev,
898 				       PREALLOC_BUFFER, PREALLOC_BUFFER_MAX);
899 	return 0;
900 }
901 
902 static struct snd_soc_dai_driver rz_ssi_soc_dai[] = {
903 	{
904 		.name			= "rz-ssi-dai",
905 		.playback = {
906 			.rates		= SSI_RATES,
907 			.formats	= SSI_FMTS,
908 			.channels_min	= SSI_CHAN_MIN,
909 			.channels_max	= SSI_CHAN_MAX,
910 		},
911 		.capture = {
912 			.rates		= SSI_RATES,
913 			.formats	= SSI_FMTS,
914 			.channels_min	= SSI_CHAN_MIN,
915 			.channels_max	= SSI_CHAN_MAX,
916 		},
917 		.ops = &rz_ssi_dai_ops,
918 	},
919 };
920 
921 static const struct snd_soc_component_driver rz_ssi_soc_component = {
922 	.name			= "rz-ssi",
923 	.open			= rz_ssi_pcm_open,
924 	.pointer		= rz_ssi_pcm_pointer,
925 	.pcm_construct		= rz_ssi_pcm_new,
926 	.legacy_dai_naming	= 1,
927 };
928 
rz_ssi_probe(struct platform_device * pdev)929 static int rz_ssi_probe(struct platform_device *pdev)
930 {
931 	struct rz_ssi_priv *ssi;
932 	struct clk *audio_clk;
933 	struct resource *res;
934 	int ret;
935 
936 	ssi = devm_kzalloc(&pdev->dev, sizeof(*ssi), GFP_KERNEL);
937 	if (!ssi)
938 		return -ENOMEM;
939 
940 	ssi->pdev = pdev;
941 	ssi->dev = &pdev->dev;
942 	ssi->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
943 	if (IS_ERR(ssi->base))
944 		return PTR_ERR(ssi->base);
945 
946 	ssi->phys = res->start;
947 	ssi->clk = devm_clk_get(&pdev->dev, "ssi");
948 	if (IS_ERR(ssi->clk))
949 		return PTR_ERR(ssi->clk);
950 
951 	ssi->sfr_clk = devm_clk_get(&pdev->dev, "ssi_sfr");
952 	if (IS_ERR(ssi->sfr_clk))
953 		return PTR_ERR(ssi->sfr_clk);
954 
955 	audio_clk = devm_clk_get(&pdev->dev, "audio_clk1");
956 	if (IS_ERR(audio_clk))
957 		return dev_err_probe(&pdev->dev, PTR_ERR(audio_clk),
958 				     "no audio clk1");
959 
960 	ssi->audio_clk_1 = clk_get_rate(audio_clk);
961 	audio_clk = devm_clk_get(&pdev->dev, "audio_clk2");
962 	if (IS_ERR(audio_clk))
963 		return dev_err_probe(&pdev->dev, PTR_ERR(audio_clk),
964 				     "no audio clk2");
965 
966 	ssi->audio_clk_2 = clk_get_rate(audio_clk);
967 	if (!(ssi->audio_clk_1 || ssi->audio_clk_2))
968 		return dev_err_probe(&pdev->dev, -EINVAL,
969 				     "no audio clk1 or audio clk2");
970 
971 	ssi->audio_mck = ssi->audio_clk_1 ? ssi->audio_clk_1 : ssi->audio_clk_2;
972 
973 	/* Detect DMA support */
974 	ret = rz_ssi_dma_request(ssi, &pdev->dev);
975 	if (ret < 0) {
976 		dev_warn(&pdev->dev, "DMA not available, using PIO\n");
977 		ssi->playback.transfer = rz_ssi_pio_send;
978 		ssi->capture.transfer = rz_ssi_pio_recv;
979 	} else {
980 		dev_info(&pdev->dev, "DMA enabled");
981 		ssi->playback.transfer = rz_ssi_dma_transfer;
982 		ssi->capture.transfer = rz_ssi_dma_transfer;
983 	}
984 
985 	ssi->playback.priv = ssi;
986 	ssi->capture.priv = ssi;
987 
988 	spin_lock_init(&ssi->lock);
989 	dev_set_drvdata(&pdev->dev, ssi);
990 
991 	/* Error Interrupt */
992 	ssi->irq_int = platform_get_irq_byname(pdev, "int_req");
993 	if (ssi->irq_int < 0) {
994 		rz_ssi_release_dma_channels(ssi);
995 		return ssi->irq_int;
996 	}
997 
998 	ret = devm_request_irq(&pdev->dev, ssi->irq_int, &rz_ssi_interrupt,
999 			       0, dev_name(&pdev->dev), ssi);
1000 	if (ret < 0) {
1001 		rz_ssi_release_dma_channels(ssi);
1002 		return dev_err_probe(&pdev->dev, ret,
1003 				     "irq request error (int_req)\n");
1004 	}
1005 
1006 	if (!rz_ssi_is_dma_enabled(ssi)) {
1007 		/* Tx and Rx interrupts (pio only) */
1008 		ssi->irq_tx = platform_get_irq_byname(pdev, "dma_tx");
1009 		ssi->irq_rx = platform_get_irq_byname(pdev, "dma_rx");
1010 		if (ssi->irq_tx == -ENXIO && ssi->irq_rx == -ENXIO) {
1011 			ssi->irq_rt = platform_get_irq_byname(pdev, "dma_rt");
1012 			if (ssi->irq_rt < 0)
1013 				return ssi->irq_rt;
1014 
1015 			ret = devm_request_irq(&pdev->dev, ssi->irq_rt,
1016 					       &rz_ssi_interrupt, 0,
1017 					       dev_name(&pdev->dev), ssi);
1018 			if (ret < 0)
1019 				return dev_err_probe(&pdev->dev, ret,
1020 						     "irq request error (dma_rt)\n");
1021 		} else {
1022 			if (ssi->irq_tx < 0)
1023 				return ssi->irq_tx;
1024 
1025 			if (ssi->irq_rx < 0)
1026 				return ssi->irq_rx;
1027 
1028 			ret = devm_request_irq(&pdev->dev, ssi->irq_tx,
1029 					       &rz_ssi_interrupt, 0,
1030 					       dev_name(&pdev->dev), ssi);
1031 			if (ret < 0)
1032 				return dev_err_probe(&pdev->dev, ret,
1033 						"irq request error (dma_tx)\n");
1034 
1035 			ret = devm_request_irq(&pdev->dev, ssi->irq_rx,
1036 					       &rz_ssi_interrupt, 0,
1037 					       dev_name(&pdev->dev), ssi);
1038 			if (ret < 0)
1039 				return dev_err_probe(&pdev->dev, ret,
1040 						"irq request error (dma_rx)\n");
1041 		}
1042 	}
1043 
1044 	ssi->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
1045 	if (IS_ERR(ssi->rstc)) {
1046 		ret = PTR_ERR(ssi->rstc);
1047 		goto err_reset;
1048 	}
1049 
1050 	reset_control_deassert(ssi->rstc);
1051 	pm_runtime_enable(&pdev->dev);
1052 	ret = pm_runtime_resume_and_get(&pdev->dev);
1053 	if (ret < 0) {
1054 		dev_err(&pdev->dev, "pm_runtime_resume_and_get failed\n");
1055 		goto err_pm;
1056 	}
1057 
1058 	ret = devm_snd_soc_register_component(&pdev->dev, &rz_ssi_soc_component,
1059 					      rz_ssi_soc_dai,
1060 					      ARRAY_SIZE(rz_ssi_soc_dai));
1061 	if (ret < 0) {
1062 		dev_err(&pdev->dev, "failed to register snd component\n");
1063 		goto err_snd_soc;
1064 	}
1065 
1066 	return 0;
1067 
1068 err_snd_soc:
1069 	pm_runtime_put(ssi->dev);
1070 err_pm:
1071 	pm_runtime_disable(ssi->dev);
1072 	reset_control_assert(ssi->rstc);
1073 err_reset:
1074 	rz_ssi_release_dma_channels(ssi);
1075 
1076 	return ret;
1077 }
1078 
rz_ssi_remove(struct platform_device * pdev)1079 static void rz_ssi_remove(struct platform_device *pdev)
1080 {
1081 	struct rz_ssi_priv *ssi = dev_get_drvdata(&pdev->dev);
1082 
1083 	rz_ssi_release_dma_channels(ssi);
1084 
1085 	pm_runtime_put(ssi->dev);
1086 	pm_runtime_disable(ssi->dev);
1087 	reset_control_assert(ssi->rstc);
1088 }
1089 
1090 static const struct of_device_id rz_ssi_of_match[] = {
1091 	{ .compatible = "renesas,rz-ssi", },
1092 	{/* Sentinel */},
1093 };
1094 MODULE_DEVICE_TABLE(of, rz_ssi_of_match);
1095 
1096 static struct platform_driver rz_ssi_driver = {
1097 	.driver	= {
1098 		.name	= "rz-ssi-pcm-audio",
1099 		.of_match_table = rz_ssi_of_match,
1100 	},
1101 	.probe		= rz_ssi_probe,
1102 	.remove_new	= rz_ssi_remove,
1103 };
1104 
1105 module_platform_driver(rz_ssi_driver);
1106 
1107 MODULE_LICENSE("GPL v2");
1108 MODULE_DESCRIPTION("Renesas RZ/G2L ASoC Serial Sound Interface Driver");
1109 MODULE_AUTHOR("Biju Das <biju.das.jz@bp.renesas.com>");
1110