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/pm_runtime.h>
14#include <linux/reset.h>
15#include <sound/soc.h>
16
17/* REGISTER OFFSET */
18#define SSICR			0x000
19#define SSISR			0x004
20#define SSIFCR			0x010
21#define SSIFSR			0x014
22#define SSIFTDR			0x018
23#define SSIFRDR			0x01c
24#define SSIOFR			0x020
25#define SSISCR			0x024
26
27/* SSI REGISTER BITS */
28#define SSICR_DWL(x)		(((x) & 0x7) << 19)
29#define SSICR_SWL(x)		(((x) & 0x7) << 16)
30
31#define SSICR_CKS		BIT(30)
32#define SSICR_TUIEN		BIT(29)
33#define SSICR_TOIEN		BIT(28)
34#define SSICR_RUIEN		BIT(27)
35#define SSICR_ROIEN		BIT(26)
36#define SSICR_MST		BIT(14)
37#define SSICR_BCKP		BIT(13)
38#define SSICR_LRCKP		BIT(12)
39#define SSICR_CKDV(x)		(((x) & 0xf) << 4)
40#define SSICR_TEN		BIT(1)
41#define SSICR_REN		BIT(0)
42
43#define SSISR_TUIRQ		BIT(29)
44#define SSISR_TOIRQ		BIT(28)
45#define SSISR_RUIRQ		BIT(27)
46#define SSISR_ROIRQ		BIT(26)
47#define SSISR_IIRQ		BIT(25)
48
49#define SSIFCR_AUCKE		BIT(31)
50#define SSIFCR_SSIRST		BIT(16)
51#define SSIFCR_TIE		BIT(3)
52#define SSIFCR_RIE		BIT(2)
53#define SSIFCR_TFRST		BIT(1)
54#define SSIFCR_RFRST		BIT(0)
55
56#define SSIFSR_TDC_MASK		0x3f
57#define SSIFSR_TDC_SHIFT	24
58#define SSIFSR_RDC_MASK		0x3f
59#define SSIFSR_RDC_SHIFT	8
60
61#define SSIFSR_TDE		BIT(16)
62#define SSIFSR_RDF		BIT(0)
63
64#define SSIOFR_LRCONT		BIT(8)
65
66#define SSISCR_TDES(x)		(((x) & 0x1f) << 8)
67#define SSISCR_RDFS(x)		(((x) & 0x1f) << 0)
68
69/* Pre allocated buffers sizes */
70#define PREALLOC_BUFFER		(SZ_32K)
71#define PREALLOC_BUFFER_MAX	(SZ_32K)
72
73#define SSI_RATES		SNDRV_PCM_RATE_8000_48000 /* 8k-44.1kHz */
74#define SSI_FMTS		SNDRV_PCM_FMTBIT_S16_LE
75#define SSI_CHAN_MIN		2
76#define SSI_CHAN_MAX		2
77#define SSI_FIFO_DEPTH		32
78
79struct rz_ssi_priv;
80
81struct rz_ssi_stream {
82	struct rz_ssi_priv *priv;
83	struct snd_pcm_substream *substream;
84	int fifo_sample_size;	/* sample capacity of SSI FIFO */
85	int dma_buffer_pos;	/* The address for the next DMA descriptor */
86	int period_counter;	/* for keeping track of periods transferred */
87	int sample_width;
88	int buffer_pos;		/* current frame position in the buffer */
89	int running;		/* 0=stopped, 1=running */
90
91	int uerr_num;
92	int oerr_num;
93
94	struct dma_chan *dma_ch;
95
96	int (*transfer)(struct rz_ssi_priv *ssi, struct rz_ssi_stream *strm);
97};
98
99struct rz_ssi_priv {
100	void __iomem *base;
101	struct platform_device *pdev;
102	struct reset_control *rstc;
103	struct device *dev;
104	struct clk *sfr_clk;
105	struct clk *clk;
106
107	phys_addr_t phys;
108	int irq_int;
109	int irq_tx;
110	int irq_rx;
111	int irq_rt;
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
135static void rz_ssi_dma_complete(void *data);
136
137static void rz_ssi_reg_writel(struct rz_ssi_priv *priv, uint reg, u32 data)
138{
139	writel(data, (priv->base + reg));
140}
141
142static u32 rz_ssi_reg_readl(struct rz_ssi_priv *priv, uint reg)
143{
144	return readl(priv->base + reg);
145}
146
147static 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
157static inline struct snd_soc_dai *
158rz_ssi_get_dai(struct snd_pcm_substream *substream)
159{
160	struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
161
162	return snd_soc_rtd_to_cpu(rtd, 0);
163}
164
165static 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
171static inline struct rz_ssi_stream *
172rz_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
182static 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
187static 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
198static 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
211static 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
230static 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
244static 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
306static 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
346static 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
387static 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
411static 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
464static 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
513static 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	if (irq == ssi->irq_rt) {
569		struct snd_pcm_substream *substream = strm->substream;
570
571		if (rz_ssi_stream_is_play(ssi, substream)) {
572			strm->transfer(ssi, &ssi->playback);
573		} else {
574			strm->transfer(ssi, &ssi->capture);
575			rz_ssi_reg_mask_setl(ssi, SSIFSR, SSIFSR_RDF, 0);
576		}
577	}
578
579	return IRQ_HANDLED;
580}
581
582static int rz_ssi_dma_slave_config(struct rz_ssi_priv *ssi,
583				   struct dma_chan *dma_ch, bool is_play)
584{
585	struct dma_slave_config cfg;
586
587	memset(&cfg, 0, sizeof(cfg));
588
589	cfg.direction = is_play ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
590	cfg.dst_addr = ssi->phys + SSIFTDR;
591	cfg.src_addr = ssi->phys + SSIFRDR;
592	cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
593	cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
594
595	return dmaengine_slave_config(dma_ch, &cfg);
596}
597
598static int rz_ssi_dma_transfer(struct rz_ssi_priv *ssi,
599			       struct rz_ssi_stream *strm)
600{
601	struct snd_pcm_substream *substream = strm->substream;
602	struct dma_async_tx_descriptor *desc;
603	struct snd_pcm_runtime *runtime;
604	enum dma_transfer_direction dir;
605	u32 dma_paddr, dma_size;
606	int amount;
607
608	if (!rz_ssi_stream_is_valid(ssi, strm))
609		return -EINVAL;
610
611	runtime = substream->runtime;
612	if (runtime->state == SNDRV_PCM_STATE_DRAINING)
613		/*
614		 * Stream is ending, so do not queue up any more DMA
615		 * transfers otherwise we play partial sound clips
616		 * because we can't shut off the DMA quick enough.
617		 */
618		return 0;
619
620	dir = rz_ssi_stream_is_play(ssi, substream) ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
621
622	/* Always transfer 1 period */
623	amount = runtime->period_size;
624
625	/* DMA physical address and size */
626	dma_paddr = runtime->dma_addr + frames_to_bytes(runtime,
627							strm->dma_buffer_pos);
628	dma_size = frames_to_bytes(runtime, amount);
629	desc = dmaengine_prep_slave_single(strm->dma_ch, dma_paddr, dma_size,
630					   dir,
631					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
632	if (!desc) {
633		dev_err(ssi->dev, "dmaengine_prep_slave_single() fail\n");
634		return -ENOMEM;
635	}
636
637	desc->callback = rz_ssi_dma_complete;
638	desc->callback_param = strm;
639
640	if (dmaengine_submit(desc) < 0) {
641		dev_err(ssi->dev, "dmaengine_submit() fail\n");
642		return -EIO;
643	}
644
645	/* Update DMA pointer */
646	strm->dma_buffer_pos += amount;
647	if (strm->dma_buffer_pos >= runtime->buffer_size)
648		strm->dma_buffer_pos = 0;
649
650	/* Start DMA */
651	dma_async_issue_pending(strm->dma_ch);
652
653	return 0;
654}
655
656static void rz_ssi_dma_complete(void *data)
657{
658	struct rz_ssi_stream *strm = (struct rz_ssi_stream *)data;
659
660	if (!strm->running || !strm->substream || !strm->substream->runtime)
661		return;
662
663	/* Note that next DMA transaction has probably already started */
664	rz_ssi_pointer_update(strm, strm->substream->runtime->period_size);
665
666	/* Queue up another DMA transaction */
667	rz_ssi_dma_transfer(strm->priv, strm);
668}
669
670static void rz_ssi_release_dma_channels(struct rz_ssi_priv *ssi)
671{
672	if (ssi->playback.dma_ch) {
673		dma_release_channel(ssi->playback.dma_ch);
674		ssi->playback.dma_ch = NULL;
675		if (ssi->dma_rt)
676			ssi->dma_rt = false;
677	}
678
679	if (ssi->capture.dma_ch) {
680		dma_release_channel(ssi->capture.dma_ch);
681		ssi->capture.dma_ch = NULL;
682	}
683}
684
685static int rz_ssi_dma_request(struct rz_ssi_priv *ssi, struct device *dev)
686{
687	ssi->playback.dma_ch = dma_request_chan(dev, "tx");
688	if (IS_ERR(ssi->playback.dma_ch))
689		ssi->playback.dma_ch = NULL;
690
691	ssi->capture.dma_ch = dma_request_chan(dev, "rx");
692	if (IS_ERR(ssi->capture.dma_ch))
693		ssi->capture.dma_ch = NULL;
694
695	if (!ssi->playback.dma_ch && !ssi->capture.dma_ch) {
696		ssi->playback.dma_ch = dma_request_chan(dev, "rt");
697		if (IS_ERR(ssi->playback.dma_ch)) {
698			ssi->playback.dma_ch = NULL;
699			goto no_dma;
700		}
701
702		ssi->dma_rt = true;
703	}
704
705	if (!rz_ssi_is_dma_enabled(ssi))
706		goto no_dma;
707
708	if (ssi->playback.dma_ch &&
709	    (rz_ssi_dma_slave_config(ssi, ssi->playback.dma_ch, true) < 0))
710		goto no_dma;
711
712	if (ssi->capture.dma_ch &&
713	    (rz_ssi_dma_slave_config(ssi, ssi->capture.dma_ch, false) < 0))
714		goto no_dma;
715
716	return 0;
717
718no_dma:
719	rz_ssi_release_dma_channels(ssi);
720
721	return -ENODEV;
722}
723
724static int rz_ssi_dai_trigger(struct snd_pcm_substream *substream, int cmd,
725			      struct snd_soc_dai *dai)
726{
727	struct rz_ssi_priv *ssi = snd_soc_dai_get_drvdata(dai);
728	struct rz_ssi_stream *strm = rz_ssi_stream_get(ssi, substream);
729	int ret = 0, i, num_transfer = 1;
730
731	switch (cmd) {
732	case SNDRV_PCM_TRIGGER_START:
733		/* Soft Reset */
734		rz_ssi_reg_mask_setl(ssi, SSIFCR, 0, SSIFCR_SSIRST);
735		rz_ssi_reg_mask_setl(ssi, SSIFCR, SSIFCR_SSIRST, 0);
736		udelay(5);
737
738		rz_ssi_stream_init(strm, substream);
739
740		if (ssi->dma_rt) {
741			bool is_playback;
742
743			is_playback = rz_ssi_stream_is_play(ssi, substream);
744			ret = rz_ssi_dma_slave_config(ssi, ssi->playback.dma_ch,
745						      is_playback);
746			/* Fallback to pio */
747			if (ret < 0) {
748				ssi->playback.transfer = rz_ssi_pio_send;
749				ssi->capture.transfer = rz_ssi_pio_recv;
750				rz_ssi_release_dma_channels(ssi);
751			}
752		}
753
754		/* For DMA, queue up multiple DMA descriptors */
755		if (rz_ssi_is_dma_enabled(ssi))
756			num_transfer = 4;
757
758		for (i = 0; i < num_transfer; i++) {
759			ret = strm->transfer(ssi, strm);
760			if (ret)
761				goto done;
762		}
763
764		ret = rz_ssi_start(ssi, strm);
765		break;
766	case SNDRV_PCM_TRIGGER_STOP:
767		rz_ssi_stop(ssi, strm);
768		rz_ssi_stream_quit(ssi, strm);
769		break;
770	}
771
772done:
773	return ret;
774}
775
776static int rz_ssi_dai_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
777{
778	struct rz_ssi_priv *ssi = snd_soc_dai_get_drvdata(dai);
779
780	switch (fmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK) {
781	case SND_SOC_DAIFMT_BP_FP:
782		break;
783	default:
784		dev_err(ssi->dev, "Codec should be clk and frame consumer\n");
785		return -EINVAL;
786	}
787
788	/*
789	 * set clock polarity
790	 *
791	 * "normal" BCLK = Signal is available at rising edge of BCLK
792	 * "normal" FSYNC = (I2S) Left ch starts with falling FSYNC edge
793	 */
794	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
795	case SND_SOC_DAIFMT_NB_NF:
796		ssi->bckp_rise = false;
797		ssi->lrckp_fsync_fall = false;
798		break;
799	case SND_SOC_DAIFMT_NB_IF:
800		ssi->bckp_rise = false;
801		ssi->lrckp_fsync_fall = true;
802		break;
803	case SND_SOC_DAIFMT_IB_NF:
804		ssi->bckp_rise = true;
805		ssi->lrckp_fsync_fall = false;
806		break;
807	case SND_SOC_DAIFMT_IB_IF:
808		ssi->bckp_rise = true;
809		ssi->lrckp_fsync_fall = true;
810		break;
811	default:
812		return -EINVAL;
813	}
814
815	/* only i2s support */
816	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
817	case SND_SOC_DAIFMT_I2S:
818		break;
819	default:
820		dev_err(ssi->dev, "Only I2S mode is supported.\n");
821		return -EINVAL;
822	}
823
824	return 0;
825}
826
827static int rz_ssi_dai_hw_params(struct snd_pcm_substream *substream,
828				struct snd_pcm_hw_params *params,
829				struct snd_soc_dai *dai)
830{
831	struct rz_ssi_priv *ssi = snd_soc_dai_get_drvdata(dai);
832	unsigned int sample_bits = hw_param_interval(params,
833					SNDRV_PCM_HW_PARAM_SAMPLE_BITS)->min;
834	unsigned int channels = params_channels(params);
835
836	if (sample_bits != 16) {
837		dev_err(ssi->dev, "Unsupported sample width: %d\n",
838			sample_bits);
839		return -EINVAL;
840	}
841
842	if (channels != 2) {
843		dev_err(ssi->dev, "Number of channels not matched: %d\n",
844			channels);
845		return -EINVAL;
846	}
847
848	return rz_ssi_clk_setup(ssi, params_rate(params),
849				params_channels(params));
850}
851
852static const struct snd_soc_dai_ops rz_ssi_dai_ops = {
853	.trigger	= rz_ssi_dai_trigger,
854	.set_fmt	= rz_ssi_dai_set_fmt,
855	.hw_params	= rz_ssi_dai_hw_params,
856};
857
858static const struct snd_pcm_hardware rz_ssi_pcm_hardware = {
859	.info			= SNDRV_PCM_INFO_INTERLEAVED	|
860				  SNDRV_PCM_INFO_MMAP		|
861				  SNDRV_PCM_INFO_MMAP_VALID,
862	.buffer_bytes_max	= PREALLOC_BUFFER,
863	.period_bytes_min	= 32,
864	.period_bytes_max	= 8192,
865	.channels_min		= SSI_CHAN_MIN,
866	.channels_max		= SSI_CHAN_MAX,
867	.periods_min		= 1,
868	.periods_max		= 32,
869	.fifo_size		= 32 * 2,
870};
871
872static int rz_ssi_pcm_open(struct snd_soc_component *component,
873			   struct snd_pcm_substream *substream)
874{
875	snd_soc_set_runtime_hwparams(substream, &rz_ssi_pcm_hardware);
876
877	return snd_pcm_hw_constraint_integer(substream->runtime,
878					    SNDRV_PCM_HW_PARAM_PERIODS);
879}
880
881static snd_pcm_uframes_t rz_ssi_pcm_pointer(struct snd_soc_component *component,
882					    struct snd_pcm_substream *substream)
883{
884	struct snd_soc_dai *dai = rz_ssi_get_dai(substream);
885	struct rz_ssi_priv *ssi = snd_soc_dai_get_drvdata(dai);
886	struct rz_ssi_stream *strm = rz_ssi_stream_get(ssi, substream);
887
888	return strm->buffer_pos;
889}
890
891static int rz_ssi_pcm_new(struct snd_soc_component *component,
892			  struct snd_soc_pcm_runtime *rtd)
893{
894	snd_pcm_set_managed_buffer_all(rtd->pcm, SNDRV_DMA_TYPE_DEV,
895				       rtd->card->snd_card->dev,
896				       PREALLOC_BUFFER, PREALLOC_BUFFER_MAX);
897	return 0;
898}
899
900static struct snd_soc_dai_driver rz_ssi_soc_dai[] = {
901	{
902		.name			= "rz-ssi-dai",
903		.playback = {
904			.rates		= SSI_RATES,
905			.formats	= SSI_FMTS,
906			.channels_min	= SSI_CHAN_MIN,
907			.channels_max	= SSI_CHAN_MAX,
908		},
909		.capture = {
910			.rates		= SSI_RATES,
911			.formats	= SSI_FMTS,
912			.channels_min	= SSI_CHAN_MIN,
913			.channels_max	= SSI_CHAN_MAX,
914		},
915		.ops = &rz_ssi_dai_ops,
916	},
917};
918
919static const struct snd_soc_component_driver rz_ssi_soc_component = {
920	.name			= "rz-ssi",
921	.open			= rz_ssi_pcm_open,
922	.pointer		= rz_ssi_pcm_pointer,
923	.pcm_construct		= rz_ssi_pcm_new,
924	.legacy_dai_naming	= 1,
925};
926
927static int rz_ssi_probe(struct platform_device *pdev)
928{
929	struct rz_ssi_priv *ssi;
930	struct clk *audio_clk;
931	struct resource *res;
932	int ret;
933
934	ssi = devm_kzalloc(&pdev->dev, sizeof(*ssi), GFP_KERNEL);
935	if (!ssi)
936		return -ENOMEM;
937
938	ssi->pdev = pdev;
939	ssi->dev = &pdev->dev;
940	ssi->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
941	if (IS_ERR(ssi->base))
942		return PTR_ERR(ssi->base);
943
944	ssi->phys = res->start;
945	ssi->clk = devm_clk_get(&pdev->dev, "ssi");
946	if (IS_ERR(ssi->clk))
947		return PTR_ERR(ssi->clk);
948
949	ssi->sfr_clk = devm_clk_get(&pdev->dev, "ssi_sfr");
950	if (IS_ERR(ssi->sfr_clk))
951		return PTR_ERR(ssi->sfr_clk);
952
953	audio_clk = devm_clk_get(&pdev->dev, "audio_clk1");
954	if (IS_ERR(audio_clk))
955		return dev_err_probe(&pdev->dev, PTR_ERR(audio_clk),
956				     "no audio clk1");
957
958	ssi->audio_clk_1 = clk_get_rate(audio_clk);
959	audio_clk = devm_clk_get(&pdev->dev, "audio_clk2");
960	if (IS_ERR(audio_clk))
961		return dev_err_probe(&pdev->dev, PTR_ERR(audio_clk),
962				     "no audio clk2");
963
964	ssi->audio_clk_2 = clk_get_rate(audio_clk);
965	if (!(ssi->audio_clk_1 || ssi->audio_clk_2))
966		return dev_err_probe(&pdev->dev, -EINVAL,
967				     "no audio clk1 or audio clk2");
968
969	ssi->audio_mck = ssi->audio_clk_1 ? ssi->audio_clk_1 : ssi->audio_clk_2;
970
971	/* Detect DMA support */
972	ret = rz_ssi_dma_request(ssi, &pdev->dev);
973	if (ret < 0) {
974		dev_warn(&pdev->dev, "DMA not available, using PIO\n");
975		ssi->playback.transfer = rz_ssi_pio_send;
976		ssi->capture.transfer = rz_ssi_pio_recv;
977	} else {
978		dev_info(&pdev->dev, "DMA enabled");
979		ssi->playback.transfer = rz_ssi_dma_transfer;
980		ssi->capture.transfer = rz_ssi_dma_transfer;
981	}
982
983	ssi->playback.priv = ssi;
984	ssi->capture.priv = ssi;
985
986	spin_lock_init(&ssi->lock);
987	dev_set_drvdata(&pdev->dev, ssi);
988
989	/* Error Interrupt */
990	ssi->irq_int = platform_get_irq_byname(pdev, "int_req");
991	if (ssi->irq_int < 0) {
992		rz_ssi_release_dma_channels(ssi);
993		return ssi->irq_int;
994	}
995
996	ret = devm_request_irq(&pdev->dev, ssi->irq_int, &rz_ssi_interrupt,
997			       0, dev_name(&pdev->dev), ssi);
998	if (ret < 0) {
999		rz_ssi_release_dma_channels(ssi);
1000		return dev_err_probe(&pdev->dev, ret,
1001				     "irq request error (int_req)\n");
1002	}
1003
1004	if (!rz_ssi_is_dma_enabled(ssi)) {
1005		/* Tx and Rx interrupts (pio only) */
1006		ssi->irq_tx = platform_get_irq_byname(pdev, "dma_tx");
1007		ssi->irq_rx = platform_get_irq_byname(pdev, "dma_rx");
1008		if (ssi->irq_tx == -ENXIO && ssi->irq_rx == -ENXIO) {
1009			ssi->irq_rt = platform_get_irq_byname(pdev, "dma_rt");
1010			if (ssi->irq_rt < 0)
1011				return ssi->irq_rt;
1012
1013			ret = devm_request_irq(&pdev->dev, ssi->irq_rt,
1014					       &rz_ssi_interrupt, 0,
1015					       dev_name(&pdev->dev), ssi);
1016			if (ret < 0)
1017				return dev_err_probe(&pdev->dev, ret,
1018						     "irq request error (dma_rt)\n");
1019		} else {
1020			if (ssi->irq_tx < 0)
1021				return ssi->irq_tx;
1022
1023			if (ssi->irq_rx < 0)
1024				return ssi->irq_rx;
1025
1026			ret = devm_request_irq(&pdev->dev, ssi->irq_tx,
1027					       &rz_ssi_interrupt, 0,
1028					       dev_name(&pdev->dev), ssi);
1029			if (ret < 0)
1030				return dev_err_probe(&pdev->dev, ret,
1031						"irq request error (dma_tx)\n");
1032
1033			ret = devm_request_irq(&pdev->dev, ssi->irq_rx,
1034					       &rz_ssi_interrupt, 0,
1035					       dev_name(&pdev->dev), ssi);
1036			if (ret < 0)
1037				return dev_err_probe(&pdev->dev, ret,
1038						"irq request error (dma_rx)\n");
1039		}
1040	}
1041
1042	ssi->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
1043	if (IS_ERR(ssi->rstc)) {
1044		ret = PTR_ERR(ssi->rstc);
1045		goto err_reset;
1046	}
1047
1048	reset_control_deassert(ssi->rstc);
1049	pm_runtime_enable(&pdev->dev);
1050	ret = pm_runtime_resume_and_get(&pdev->dev);
1051	if (ret < 0) {
1052		dev_err(&pdev->dev, "pm_runtime_resume_and_get failed\n");
1053		goto err_pm;
1054	}
1055
1056	ret = devm_snd_soc_register_component(&pdev->dev, &rz_ssi_soc_component,
1057					      rz_ssi_soc_dai,
1058					      ARRAY_SIZE(rz_ssi_soc_dai));
1059	if (ret < 0) {
1060		dev_err(&pdev->dev, "failed to register snd component\n");
1061		goto err_snd_soc;
1062	}
1063
1064	return 0;
1065
1066err_snd_soc:
1067	pm_runtime_put(ssi->dev);
1068err_pm:
1069	pm_runtime_disable(ssi->dev);
1070	reset_control_assert(ssi->rstc);
1071err_reset:
1072	rz_ssi_release_dma_channels(ssi);
1073
1074	return ret;
1075}
1076
1077static void rz_ssi_remove(struct platform_device *pdev)
1078{
1079	struct rz_ssi_priv *ssi = dev_get_drvdata(&pdev->dev);
1080
1081	rz_ssi_release_dma_channels(ssi);
1082
1083	pm_runtime_put(ssi->dev);
1084	pm_runtime_disable(ssi->dev);
1085	reset_control_assert(ssi->rstc);
1086}
1087
1088static const struct of_device_id rz_ssi_of_match[] = {
1089	{ .compatible = "renesas,rz-ssi", },
1090	{/* Sentinel */},
1091};
1092MODULE_DEVICE_TABLE(of, rz_ssi_of_match);
1093
1094static struct platform_driver rz_ssi_driver = {
1095	.driver	= {
1096		.name	= "rz-ssi-pcm-audio",
1097		.of_match_table = rz_ssi_of_match,
1098	},
1099	.probe		= rz_ssi_probe,
1100	.remove_new	= rz_ssi_remove,
1101};
1102
1103module_platform_driver(rz_ssi_driver);
1104
1105MODULE_LICENSE("GPL v2");
1106MODULE_DESCRIPTION("Renesas RZ/G2L ASoC Serial Sound Interface Driver");
1107MODULE_AUTHOR("Biju Das <biju.das.jz@bp.renesas.com>");
1108