xref: /openbmc/linux/sound/soc/fsl/mpc5200_dma.c (revision e8e0929d)
1 /*
2  * Freescale MPC5200 PSC DMA
3  * ALSA SoC Platform driver
4  *
5  * Copyright (C) 2008 Secret Lab Technologies Ltd.
6  * Copyright (C) 2009 Jon Smirl, Digispeaker
7  */
8 
9 #include <linux/module.h>
10 #include <linux/of_device.h>
11 
12 #include <sound/soc.h>
13 
14 #include <sysdev/bestcomm/bestcomm.h>
15 #include <sysdev/bestcomm/gen_bd.h>
16 #include <asm/mpc52xx_psc.h>
17 
18 #include "mpc5200_dma.h"
19 
20 /*
21  * Interrupt handlers
22  */
23 static irqreturn_t psc_dma_status_irq(int irq, void *_psc_dma)
24 {
25 	struct psc_dma *psc_dma = _psc_dma;
26 	struct mpc52xx_psc __iomem *regs = psc_dma->psc_regs;
27 	u16 isr;
28 
29 	isr = in_be16(&regs->mpc52xx_psc_isr);
30 
31 	/* Playback underrun error */
32 	if (psc_dma->playback.active && (isr & MPC52xx_PSC_IMR_TXEMP))
33 		psc_dma->stats.underrun_count++;
34 
35 	/* Capture overrun error */
36 	if (psc_dma->capture.active && (isr & MPC52xx_PSC_IMR_ORERR))
37 		psc_dma->stats.overrun_count++;
38 
39 	out_8(&regs->command, MPC52xx_PSC_RST_ERR_STAT);
40 
41 	return IRQ_HANDLED;
42 }
43 
44 /**
45  * psc_dma_bcom_enqueue_next_buffer - Enqueue another audio buffer
46  * @s: pointer to stream private data structure
47  *
48  * Enqueues another audio period buffer into the bestcomm queue.
49  *
50  * Note: The routine must only be called when there is space available in
51  * the queue.  Otherwise the enqueue will fail and the audio ring buffer
52  * will get out of sync
53  */
54 static void psc_dma_bcom_enqueue_next_buffer(struct psc_dma_stream *s)
55 {
56 	struct bcom_bd *bd;
57 
58 	/* Prepare and enqueue the next buffer descriptor */
59 	bd = bcom_prepare_next_buffer(s->bcom_task);
60 	bd->status = s->period_bytes;
61 	bd->data[0] = s->period_next_pt;
62 	bcom_submit_next_buffer(s->bcom_task, NULL);
63 
64 	/* Update for next period */
65 	s->period_next_pt += s->period_bytes;
66 	if (s->period_next_pt >= s->period_end)
67 		s->period_next_pt = s->period_start;
68 }
69 
70 static void psc_dma_bcom_enqueue_tx(struct psc_dma_stream *s)
71 {
72 	if (s->appl_ptr > s->runtime->control->appl_ptr) {
73 		/*
74 		 * In this case s->runtime->control->appl_ptr has wrapped around.
75 		 * Play the data to the end of the boundary, then wrap our own
76 		 * appl_ptr back around.
77 		 */
78 		while (s->appl_ptr < s->runtime->boundary) {
79 			if (bcom_queue_full(s->bcom_task))
80 				return;
81 
82 			s->appl_ptr += s->period_size;
83 
84 			psc_dma_bcom_enqueue_next_buffer(s);
85 		}
86 		s->appl_ptr -= s->runtime->boundary;
87 	}
88 
89 	while (s->appl_ptr < s->runtime->control->appl_ptr) {
90 
91 		if (bcom_queue_full(s->bcom_task))
92 			return;
93 
94 		s->appl_ptr += s->period_size;
95 
96 		psc_dma_bcom_enqueue_next_buffer(s);
97 	}
98 }
99 
100 /* Bestcomm DMA irq handler */
101 static irqreturn_t psc_dma_bcom_irq_tx(int irq, void *_psc_dma_stream)
102 {
103 	struct psc_dma_stream *s = _psc_dma_stream;
104 
105 	spin_lock(&s->psc_dma->lock);
106 	/* For each finished period, dequeue the completed period buffer
107 	 * and enqueue a new one in it's place. */
108 	while (bcom_buffer_done(s->bcom_task)) {
109 		bcom_retrieve_buffer(s->bcom_task, NULL, NULL);
110 
111 		s->period_current_pt += s->period_bytes;
112 		if (s->period_current_pt >= s->period_end)
113 			s->period_current_pt = s->period_start;
114 	}
115 	psc_dma_bcom_enqueue_tx(s);
116 	spin_unlock(&s->psc_dma->lock);
117 
118 	/* If the stream is active, then also inform the PCM middle layer
119 	 * of the period finished event. */
120 	if (s->active)
121 		snd_pcm_period_elapsed(s->stream);
122 
123 	return IRQ_HANDLED;
124 }
125 
126 static irqreturn_t psc_dma_bcom_irq_rx(int irq, void *_psc_dma_stream)
127 {
128 	struct psc_dma_stream *s = _psc_dma_stream;
129 
130 	spin_lock(&s->psc_dma->lock);
131 	/* For each finished period, dequeue the completed period buffer
132 	 * and enqueue a new one in it's place. */
133 	while (bcom_buffer_done(s->bcom_task)) {
134 		bcom_retrieve_buffer(s->bcom_task, NULL, NULL);
135 
136 		s->period_current_pt += s->period_bytes;
137 		if (s->period_current_pt >= s->period_end)
138 			s->period_current_pt = s->period_start;
139 
140 		psc_dma_bcom_enqueue_next_buffer(s);
141 	}
142 	spin_unlock(&s->psc_dma->lock);
143 
144 	/* If the stream is active, then also inform the PCM middle layer
145 	 * of the period finished event. */
146 	if (s->active)
147 		snd_pcm_period_elapsed(s->stream);
148 
149 	return IRQ_HANDLED;
150 }
151 
152 static int psc_dma_hw_free(struct snd_pcm_substream *substream)
153 {
154 	snd_pcm_set_runtime_buffer(substream, NULL);
155 	return 0;
156 }
157 
158 /**
159  * psc_dma_trigger: start and stop the DMA transfer.
160  *
161  * This function is called by ALSA to start, stop, pause, and resume the DMA
162  * transfer of data.
163  */
164 static int psc_dma_trigger(struct snd_pcm_substream *substream, int cmd)
165 {
166 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
167 	struct psc_dma *psc_dma = rtd->dai->cpu_dai->private_data;
168 	struct snd_pcm_runtime *runtime = substream->runtime;
169 	struct psc_dma_stream *s;
170 	struct mpc52xx_psc __iomem *regs = psc_dma->psc_regs;
171 	u16 imr;
172 	unsigned long flags;
173 	int i;
174 
175 	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
176 		s = &psc_dma->capture;
177 	else
178 		s = &psc_dma->playback;
179 
180 	dev_dbg(psc_dma->dev, "psc_dma_trigger(substream=%p, cmd=%i)"
181 		" stream_id=%i\n",
182 		substream, cmd, substream->pstr->stream);
183 
184 	switch (cmd) {
185 	case SNDRV_PCM_TRIGGER_START:
186 		s->period_bytes = frames_to_bytes(runtime,
187 						  runtime->period_size);
188 		s->period_start = virt_to_phys(runtime->dma_area);
189 		s->period_end = s->period_start +
190 				(s->period_bytes * runtime->periods);
191 		s->period_next_pt = s->period_start;
192 		s->period_current_pt = s->period_start;
193 		s->period_size = runtime->period_size;
194 		s->active = 1;
195 
196 		/* track appl_ptr so that we have a better chance of detecting
197 		 * end of stream and not over running it.
198 		 */
199 		s->runtime = runtime;
200 		s->appl_ptr = s->runtime->control->appl_ptr -
201 				(runtime->period_size * runtime->periods);
202 
203 		/* Fill up the bestcomm bd queue and enable DMA.
204 		 * This will begin filling the PSC's fifo.
205 		 */
206 		spin_lock_irqsave(&psc_dma->lock, flags);
207 
208 		if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE) {
209 			bcom_gen_bd_rx_reset(s->bcom_task);
210 			for (i = 0; i < runtime->periods; i++)
211 				if (!bcom_queue_full(s->bcom_task))
212 					psc_dma_bcom_enqueue_next_buffer(s);
213 		} else {
214 			bcom_gen_bd_tx_reset(s->bcom_task);
215 			psc_dma_bcom_enqueue_tx(s);
216 		}
217 
218 		bcom_enable(s->bcom_task);
219 		spin_unlock_irqrestore(&psc_dma->lock, flags);
220 
221 		out_8(&regs->command, MPC52xx_PSC_RST_ERR_STAT);
222 
223 		break;
224 
225 	case SNDRV_PCM_TRIGGER_STOP:
226 		s->active = 0;
227 
228 		spin_lock_irqsave(&psc_dma->lock, flags);
229 		bcom_disable(s->bcom_task);
230 		if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
231 			bcom_gen_bd_rx_reset(s->bcom_task);
232 		else
233 			bcom_gen_bd_tx_reset(s->bcom_task);
234 		spin_unlock_irqrestore(&psc_dma->lock, flags);
235 
236 		break;
237 
238 	default:
239 		dev_dbg(psc_dma->dev, "invalid command\n");
240 		return -EINVAL;
241 	}
242 
243 	/* Update interrupt enable settings */
244 	imr = 0;
245 	if (psc_dma->playback.active)
246 		imr |= MPC52xx_PSC_IMR_TXEMP;
247 	if (psc_dma->capture.active)
248 		imr |= MPC52xx_PSC_IMR_ORERR;
249 	out_be16(&regs->isr_imr.imr, psc_dma->imr | imr);
250 
251 	return 0;
252 }
253 
254 
255 /* ---------------------------------------------------------------------
256  * The PSC DMA 'ASoC platform' driver
257  *
258  * Can be referenced by an 'ASoC machine' driver
259  * This driver only deals with the audio bus; it doesn't have any
260  * interaction with the attached codec
261  */
262 
263 static const struct snd_pcm_hardware psc_dma_hardware = {
264 	.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
265 		SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
266 		SNDRV_PCM_INFO_BATCH,
267 	.formats = SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_BE |
268 		SNDRV_PCM_FMTBIT_S24_BE | SNDRV_PCM_FMTBIT_S32_BE,
269 	.rate_min = 8000,
270 	.rate_max = 48000,
271 	.channels_min = 1,
272 	.channels_max = 2,
273 	.period_bytes_max	= 1024 * 1024,
274 	.period_bytes_min	= 32,
275 	.periods_min		= 2,
276 	.periods_max		= 256,
277 	.buffer_bytes_max	= 2 * 1024 * 1024,
278 	.fifo_size		= 512,
279 };
280 
281 static int psc_dma_open(struct snd_pcm_substream *substream)
282 {
283 	struct snd_pcm_runtime *runtime = substream->runtime;
284 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
285 	struct psc_dma *psc_dma = rtd->dai->cpu_dai->private_data;
286 	struct psc_dma_stream *s;
287 	int rc;
288 
289 	dev_dbg(psc_dma->dev, "psc_dma_open(substream=%p)\n", substream);
290 
291 	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
292 		s = &psc_dma->capture;
293 	else
294 		s = &psc_dma->playback;
295 
296 	snd_soc_set_runtime_hwparams(substream, &psc_dma_hardware);
297 
298 	rc = snd_pcm_hw_constraint_integer(runtime,
299 		SNDRV_PCM_HW_PARAM_PERIODS);
300 	if (rc < 0) {
301 		dev_err(substream->pcm->card->dev, "invalid buffer size\n");
302 		return rc;
303 	}
304 
305 	s->stream = substream;
306 	return 0;
307 }
308 
309 static int psc_dma_close(struct snd_pcm_substream *substream)
310 {
311 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
312 	struct psc_dma *psc_dma = rtd->dai->cpu_dai->private_data;
313 	struct psc_dma_stream *s;
314 
315 	dev_dbg(psc_dma->dev, "psc_dma_close(substream=%p)\n", substream);
316 
317 	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
318 		s = &psc_dma->capture;
319 	else
320 		s = &psc_dma->playback;
321 
322 	if (!psc_dma->playback.active &&
323 	    !psc_dma->capture.active) {
324 
325 		/* Disable all interrupts and reset the PSC */
326 		out_be16(&psc_dma->psc_regs->isr_imr.imr, psc_dma->imr);
327 		out_8(&psc_dma->psc_regs->command, 4 << 4); /* reset error */
328 	}
329 	s->stream = NULL;
330 	return 0;
331 }
332 
333 static snd_pcm_uframes_t
334 psc_dma_pointer(struct snd_pcm_substream *substream)
335 {
336 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
337 	struct psc_dma *psc_dma = rtd->dai->cpu_dai->private_data;
338 	struct psc_dma_stream *s;
339 	dma_addr_t count;
340 
341 	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
342 		s = &psc_dma->capture;
343 	else
344 		s = &psc_dma->playback;
345 
346 	count = s->period_current_pt - s->period_start;
347 
348 	return bytes_to_frames(substream->runtime, count);
349 }
350 
351 static int
352 psc_dma_hw_params(struct snd_pcm_substream *substream,
353 			 struct snd_pcm_hw_params *params)
354 {
355 	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
356 
357 	return 0;
358 }
359 
360 static struct snd_pcm_ops psc_dma_ops = {
361 	.open		= psc_dma_open,
362 	.close		= psc_dma_close,
363 	.hw_free	= psc_dma_hw_free,
364 	.ioctl		= snd_pcm_lib_ioctl,
365 	.pointer	= psc_dma_pointer,
366 	.trigger	= psc_dma_trigger,
367 	.hw_params	= psc_dma_hw_params,
368 };
369 
370 static u64 psc_dma_dmamask = 0xffffffff;
371 static int psc_dma_new(struct snd_card *card, struct snd_soc_dai *dai,
372 			   struct snd_pcm *pcm)
373 {
374 	struct snd_soc_pcm_runtime *rtd = pcm->private_data;
375 	struct psc_dma *psc_dma = rtd->dai->cpu_dai->private_data;
376 	size_t size = psc_dma_hardware.buffer_bytes_max;
377 	int rc = 0;
378 
379 	dev_dbg(rtd->socdev->dev, "psc_dma_new(card=%p, dai=%p, pcm=%p)\n",
380 		card, dai, pcm);
381 
382 	if (!card->dev->dma_mask)
383 		card->dev->dma_mask = &psc_dma_dmamask;
384 	if (!card->dev->coherent_dma_mask)
385 		card->dev->coherent_dma_mask = 0xffffffff;
386 
387 	if (pcm->streams[0].substream) {
388 		rc = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, pcm->card->dev,
389 				size, &pcm->streams[0].substream->dma_buffer);
390 		if (rc)
391 			goto playback_alloc_err;
392 	}
393 
394 	if (pcm->streams[1].substream) {
395 		rc = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, pcm->card->dev,
396 				size, &pcm->streams[1].substream->dma_buffer);
397 		if (rc)
398 			goto capture_alloc_err;
399 	}
400 
401 	if (rtd->socdev->card->codec->ac97)
402 		rtd->socdev->card->codec->ac97->private_data = psc_dma;
403 
404 	return 0;
405 
406  capture_alloc_err:
407 	if (pcm->streams[0].substream)
408 		snd_dma_free_pages(&pcm->streams[0].substream->dma_buffer);
409 
410  playback_alloc_err:
411 	dev_err(card->dev, "Cannot allocate buffer(s)\n");
412 
413 	return -ENOMEM;
414 }
415 
416 static void psc_dma_free(struct snd_pcm *pcm)
417 {
418 	struct snd_soc_pcm_runtime *rtd = pcm->private_data;
419 	struct snd_pcm_substream *substream;
420 	int stream;
421 
422 	dev_dbg(rtd->socdev->dev, "psc_dma_free(pcm=%p)\n", pcm);
423 
424 	for (stream = 0; stream < 2; stream++) {
425 		substream = pcm->streams[stream].substream;
426 		if (substream) {
427 			snd_dma_free_pages(&substream->dma_buffer);
428 			substream->dma_buffer.area = NULL;
429 			substream->dma_buffer.addr = 0;
430 		}
431 	}
432 }
433 
434 struct snd_soc_platform mpc5200_audio_dma_platform = {
435 	.name		= "mpc5200-psc-audio",
436 	.pcm_ops	= &psc_dma_ops,
437 	.pcm_new	= &psc_dma_new,
438 	.pcm_free	= &psc_dma_free,
439 };
440 EXPORT_SYMBOL_GPL(mpc5200_audio_dma_platform);
441 
442 int mpc5200_audio_dma_create(struct of_device *op)
443 {
444 	phys_addr_t fifo;
445 	struct psc_dma *psc_dma;
446 	struct resource res;
447 	int size, irq, rc;
448 	const __be32 *prop;
449 	void __iomem *regs;
450 	int ret;
451 
452 	/* Fetch the registers and IRQ of the PSC */
453 	irq = irq_of_parse_and_map(op->node, 0);
454 	if (of_address_to_resource(op->node, 0, &res)) {
455 		dev_err(&op->dev, "Missing reg property\n");
456 		return -ENODEV;
457 	}
458 	regs = ioremap(res.start, 1 + res.end - res.start);
459 	if (!regs) {
460 		dev_err(&op->dev, "Could not map registers\n");
461 		return -ENODEV;
462 	}
463 
464 	/* Allocate and initialize the driver private data */
465 	psc_dma = kzalloc(sizeof *psc_dma, GFP_KERNEL);
466 	if (!psc_dma) {
467 		ret = -ENOMEM;
468 		goto out_unmap;
469 	}
470 
471 	/* Get the PSC ID */
472 	prop = of_get_property(op->node, "cell-index", &size);
473 	if (!prop || size < sizeof *prop) {
474 		ret = -ENODEV;
475 		goto out_free;
476 	}
477 
478 	spin_lock_init(&psc_dma->lock);
479 	mutex_init(&psc_dma->mutex);
480 	psc_dma->id = be32_to_cpu(*prop);
481 	psc_dma->irq = irq;
482 	psc_dma->psc_regs = regs;
483 	psc_dma->fifo_regs = regs + sizeof *psc_dma->psc_regs;
484 	psc_dma->dev = &op->dev;
485 	psc_dma->playback.psc_dma = psc_dma;
486 	psc_dma->capture.psc_dma = psc_dma;
487 	snprintf(psc_dma->name, sizeof psc_dma->name, "PSC%u", psc_dma->id);
488 
489 	/* Find the address of the fifo data registers and setup the
490 	 * DMA tasks */
491 	fifo = res.start + offsetof(struct mpc52xx_psc, buffer.buffer_32);
492 	psc_dma->capture.bcom_task =
493 		bcom_psc_gen_bd_rx_init(psc_dma->id, 10, fifo, 512);
494 	psc_dma->playback.bcom_task =
495 		bcom_psc_gen_bd_tx_init(psc_dma->id, 10, fifo);
496 	if (!psc_dma->capture.bcom_task ||
497 	    !psc_dma->playback.bcom_task) {
498 		dev_err(&op->dev, "Could not allocate bestcomm tasks\n");
499 		ret = -ENODEV;
500 		goto out_free;
501 	}
502 
503 	/* Disable all interrupts and reset the PSC */
504 	out_be16(&psc_dma->psc_regs->isr_imr.imr, psc_dma->imr);
505 	 /* reset receiver */
506 	out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_RST_RX);
507 	 /* reset transmitter */
508 	out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_RST_TX);
509 	 /* reset error */
510 	out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_RST_ERR_STAT);
511 	 /* reset mode */
512 	out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_SEL_MODE_REG_1);
513 
514 	/* Set up mode register;
515 	 * First write: RxRdy (FIFO Alarm) generates rx FIFO irq
516 	 * Second write: register Normal mode for non loopback
517 	 */
518 	out_8(&psc_dma->psc_regs->mode, 0);
519 	out_8(&psc_dma->psc_regs->mode, 0);
520 
521 	/* Set the TX and RX fifo alarm thresholds */
522 	out_be16(&psc_dma->fifo_regs->rfalarm, 0x100);
523 	out_8(&psc_dma->fifo_regs->rfcntl, 0x4);
524 	out_be16(&psc_dma->fifo_regs->tfalarm, 0x100);
525 	out_8(&psc_dma->fifo_regs->tfcntl, 0x7);
526 
527 	/* Lookup the IRQ numbers */
528 	psc_dma->playback.irq =
529 		bcom_get_task_irq(psc_dma->playback.bcom_task);
530 	psc_dma->capture.irq =
531 		bcom_get_task_irq(psc_dma->capture.bcom_task);
532 
533 	rc = request_irq(psc_dma->irq, &psc_dma_status_irq, IRQF_SHARED,
534 			 "psc-dma-status", psc_dma);
535 	rc |= request_irq(psc_dma->capture.irq,
536 			  &psc_dma_bcom_irq_rx, IRQF_SHARED,
537 			  "psc-dma-capture", &psc_dma->capture);
538 	rc |= request_irq(psc_dma->playback.irq,
539 			  &psc_dma_bcom_irq_tx, IRQF_SHARED,
540 			  "psc-dma-playback", &psc_dma->playback);
541 	if (rc) {
542 		ret = -ENODEV;
543 		goto out_irq;
544 	}
545 
546 	/* Save what we've done so it can be found again later */
547 	dev_set_drvdata(&op->dev, psc_dma);
548 
549 	/* Tell the ASoC OF helpers about it */
550 	return snd_soc_register_platform(&mpc5200_audio_dma_platform);
551 out_irq:
552 	free_irq(psc_dma->irq, psc_dma);
553 	free_irq(psc_dma->capture.irq, &psc_dma->capture);
554 	free_irq(psc_dma->playback.irq, &psc_dma->playback);
555 out_free:
556 	kfree(psc_dma);
557 out_unmap:
558 	iounmap(regs);
559 	return ret;
560 }
561 EXPORT_SYMBOL_GPL(mpc5200_audio_dma_create);
562 
563 int mpc5200_audio_dma_destroy(struct of_device *op)
564 {
565 	struct psc_dma *psc_dma = dev_get_drvdata(&op->dev);
566 
567 	dev_dbg(&op->dev, "mpc5200_audio_dma_destroy()\n");
568 
569 	snd_soc_unregister_platform(&mpc5200_audio_dma_platform);
570 
571 	bcom_gen_bd_rx_release(psc_dma->capture.bcom_task);
572 	bcom_gen_bd_tx_release(psc_dma->playback.bcom_task);
573 
574 	/* Release irqs */
575 	free_irq(psc_dma->irq, psc_dma);
576 	free_irq(psc_dma->capture.irq, &psc_dma->capture);
577 	free_irq(psc_dma->playback.irq, &psc_dma->playback);
578 
579 	iounmap(psc_dma->psc_regs);
580 	kfree(psc_dma);
581 	dev_set_drvdata(&op->dev, NULL);
582 
583 	return 0;
584 }
585 EXPORT_SYMBOL_GPL(mpc5200_audio_dma_destroy);
586 
587 MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
588 MODULE_DESCRIPTION("Freescale MPC5200 PSC in DMA mode ASoC Driver");
589 MODULE_LICENSE("GPL");
590