xref: /openbmc/linux/sound/soc/fsl/mpc5200_dma.c (revision 77d84ff8)
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 #include <linux/dma-mapping.h>
12 #include <linux/slab.h>
13 #include <linux/of_address.h>
14 #include <linux/of_irq.h>
15 #include <linux/of_platform.h>
16 
17 #include <sound/soc.h>
18 
19 #include <linux/fsl/bestcomm/bestcomm.h>
20 #include <linux/fsl/bestcomm/gen_bd.h>
21 #include <asm/mpc52xx_psc.h>
22 
23 #include "mpc5200_dma.h"
24 
25 /*
26  * Interrupt handlers
27  */
28 static irqreturn_t psc_dma_status_irq(int irq, void *_psc_dma)
29 {
30 	struct psc_dma *psc_dma = _psc_dma;
31 	struct mpc52xx_psc __iomem *regs = psc_dma->psc_regs;
32 	u16 isr;
33 
34 	isr = in_be16(&regs->mpc52xx_psc_isr);
35 
36 	/* Playback underrun error */
37 	if (psc_dma->playback.active && (isr & MPC52xx_PSC_IMR_TXEMP))
38 		psc_dma->stats.underrun_count++;
39 
40 	/* Capture overrun error */
41 	if (psc_dma->capture.active && (isr & MPC52xx_PSC_IMR_ORERR))
42 		psc_dma->stats.overrun_count++;
43 
44 	out_8(&regs->command, MPC52xx_PSC_RST_ERR_STAT);
45 
46 	return IRQ_HANDLED;
47 }
48 
49 /**
50  * psc_dma_bcom_enqueue_next_buffer - Enqueue another audio buffer
51  * @s: pointer to stream private data structure
52  *
53  * Enqueues another audio period buffer into the bestcomm queue.
54  *
55  * Note: The routine must only be called when there is space available in
56  * the queue.  Otherwise the enqueue will fail and the audio ring buffer
57  * will get out of sync
58  */
59 static void psc_dma_bcom_enqueue_next_buffer(struct psc_dma_stream *s)
60 {
61 	struct bcom_bd *bd;
62 
63 	/* Prepare and enqueue the next buffer descriptor */
64 	bd = bcom_prepare_next_buffer(s->bcom_task);
65 	bd->status = s->period_bytes;
66 	bd->data[0] = s->runtime->dma_addr + (s->period_next * s->period_bytes);
67 	bcom_submit_next_buffer(s->bcom_task, NULL);
68 
69 	/* Update for next period */
70 	s->period_next = (s->period_next + 1) % s->runtime->periods;
71 }
72 
73 /* Bestcomm DMA irq handler */
74 static irqreturn_t psc_dma_bcom_irq(int irq, void *_psc_dma_stream)
75 {
76 	struct psc_dma_stream *s = _psc_dma_stream;
77 
78 	spin_lock(&s->psc_dma->lock);
79 	/* For each finished period, dequeue the completed period buffer
80 	 * and enqueue a new one in it's place. */
81 	while (bcom_buffer_done(s->bcom_task)) {
82 		bcom_retrieve_buffer(s->bcom_task, NULL, NULL);
83 
84 		s->period_current = (s->period_current+1) % s->runtime->periods;
85 		s->period_count++;
86 
87 		psc_dma_bcom_enqueue_next_buffer(s);
88 	}
89 	spin_unlock(&s->psc_dma->lock);
90 
91 	/* If the stream is active, then also inform the PCM middle layer
92 	 * of the period finished event. */
93 	if (s->active)
94 		snd_pcm_period_elapsed(s->stream);
95 
96 	return IRQ_HANDLED;
97 }
98 
99 static int psc_dma_hw_free(struct snd_pcm_substream *substream)
100 {
101 	snd_pcm_set_runtime_buffer(substream, NULL);
102 	return 0;
103 }
104 
105 /**
106  * psc_dma_trigger: start and stop the DMA transfer.
107  *
108  * This function is called by ALSA to start, stop, pause, and resume the DMA
109  * transfer of data.
110  */
111 static int psc_dma_trigger(struct snd_pcm_substream *substream, int cmd)
112 {
113 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
114 	struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(rtd->cpu_dai);
115 	struct snd_pcm_runtime *runtime = substream->runtime;
116 	struct psc_dma_stream *s = to_psc_dma_stream(substream, psc_dma);
117 	struct mpc52xx_psc __iomem *regs = psc_dma->psc_regs;
118 	u16 imr;
119 	unsigned long flags;
120 	int i;
121 
122 	switch (cmd) {
123 	case SNDRV_PCM_TRIGGER_START:
124 		dev_dbg(psc_dma->dev, "START: stream=%i fbits=%u ps=%u #p=%u\n",
125 			substream->pstr->stream, runtime->frame_bits,
126 			(int)runtime->period_size, runtime->periods);
127 		s->period_bytes = frames_to_bytes(runtime,
128 						  runtime->period_size);
129 		s->period_next = 0;
130 		s->period_current = 0;
131 		s->active = 1;
132 		s->period_count = 0;
133 		s->runtime = runtime;
134 
135 		/* Fill up the bestcomm bd queue and enable DMA.
136 		 * This will begin filling the PSC's fifo.
137 		 */
138 		spin_lock_irqsave(&psc_dma->lock, flags);
139 
140 		if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
141 			bcom_gen_bd_rx_reset(s->bcom_task);
142 		else
143 			bcom_gen_bd_tx_reset(s->bcom_task);
144 
145 		for (i = 0; i < runtime->periods; i++)
146 			if (!bcom_queue_full(s->bcom_task))
147 				psc_dma_bcom_enqueue_next_buffer(s);
148 
149 		bcom_enable(s->bcom_task);
150 		spin_unlock_irqrestore(&psc_dma->lock, flags);
151 
152 		out_8(&regs->command, MPC52xx_PSC_RST_ERR_STAT);
153 
154 		break;
155 
156 	case SNDRV_PCM_TRIGGER_STOP:
157 		dev_dbg(psc_dma->dev, "STOP: stream=%i periods_count=%i\n",
158 			substream->pstr->stream, s->period_count);
159 		s->active = 0;
160 
161 		spin_lock_irqsave(&psc_dma->lock, flags);
162 		bcom_disable(s->bcom_task);
163 		if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
164 			bcom_gen_bd_rx_reset(s->bcom_task);
165 		else
166 			bcom_gen_bd_tx_reset(s->bcom_task);
167 		spin_unlock_irqrestore(&psc_dma->lock, flags);
168 
169 		break;
170 
171 	default:
172 		dev_dbg(psc_dma->dev, "unhandled trigger: stream=%i cmd=%i\n",
173 			substream->pstr->stream, cmd);
174 		return -EINVAL;
175 	}
176 
177 	/* Update interrupt enable settings */
178 	imr = 0;
179 	if (psc_dma->playback.active)
180 		imr |= MPC52xx_PSC_IMR_TXEMP;
181 	if (psc_dma->capture.active)
182 		imr |= MPC52xx_PSC_IMR_ORERR;
183 	out_be16(&regs->isr_imr.imr, psc_dma->imr | imr);
184 
185 	return 0;
186 }
187 
188 
189 /* ---------------------------------------------------------------------
190  * The PSC DMA 'ASoC platform' driver
191  *
192  * Can be referenced by an 'ASoC machine' driver
193  * This driver only deals with the audio bus; it doesn't have any
194  * interaction with the attached codec
195  */
196 
197 static const struct snd_pcm_hardware psc_dma_hardware = {
198 	.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
199 		SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
200 		SNDRV_PCM_INFO_BATCH,
201 	.formats = SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_BE |
202 		SNDRV_PCM_FMTBIT_S24_BE | SNDRV_PCM_FMTBIT_S32_BE,
203 	.rate_min = 8000,
204 	.rate_max = 48000,
205 	.channels_min = 1,
206 	.channels_max = 2,
207 	.period_bytes_max	= 1024 * 1024,
208 	.period_bytes_min	= 32,
209 	.periods_min		= 2,
210 	.periods_max		= 256,
211 	.buffer_bytes_max	= 2 * 1024 * 1024,
212 	.fifo_size		= 512,
213 };
214 
215 static int psc_dma_open(struct snd_pcm_substream *substream)
216 {
217 	struct snd_pcm_runtime *runtime = substream->runtime;
218 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
219 	struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(rtd->cpu_dai);
220 	struct psc_dma_stream *s;
221 	int rc;
222 
223 	dev_dbg(psc_dma->dev, "psc_dma_open(substream=%p)\n", substream);
224 
225 	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
226 		s = &psc_dma->capture;
227 	else
228 		s = &psc_dma->playback;
229 
230 	snd_soc_set_runtime_hwparams(substream, &psc_dma_hardware);
231 
232 	rc = snd_pcm_hw_constraint_integer(runtime,
233 		SNDRV_PCM_HW_PARAM_PERIODS);
234 	if (rc < 0) {
235 		dev_err(substream->pcm->card->dev, "invalid buffer size\n");
236 		return rc;
237 	}
238 
239 	s->stream = substream;
240 	return 0;
241 }
242 
243 static int psc_dma_close(struct snd_pcm_substream *substream)
244 {
245 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
246 	struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(rtd->cpu_dai);
247 	struct psc_dma_stream *s;
248 
249 	dev_dbg(psc_dma->dev, "psc_dma_close(substream=%p)\n", substream);
250 
251 	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
252 		s = &psc_dma->capture;
253 	else
254 		s = &psc_dma->playback;
255 
256 	if (!psc_dma->playback.active &&
257 	    !psc_dma->capture.active) {
258 
259 		/* Disable all interrupts and reset the PSC */
260 		out_be16(&psc_dma->psc_regs->isr_imr.imr, psc_dma->imr);
261 		out_8(&psc_dma->psc_regs->command, 4 << 4); /* reset error */
262 	}
263 	s->stream = NULL;
264 	return 0;
265 }
266 
267 static snd_pcm_uframes_t
268 psc_dma_pointer(struct snd_pcm_substream *substream)
269 {
270 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
271 	struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(rtd->cpu_dai);
272 	struct psc_dma_stream *s;
273 	dma_addr_t count;
274 
275 	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
276 		s = &psc_dma->capture;
277 	else
278 		s = &psc_dma->playback;
279 
280 	count = s->period_current * s->period_bytes;
281 
282 	return bytes_to_frames(substream->runtime, count);
283 }
284 
285 static int
286 psc_dma_hw_params(struct snd_pcm_substream *substream,
287 			 struct snd_pcm_hw_params *params)
288 {
289 	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
290 
291 	return 0;
292 }
293 
294 static struct snd_pcm_ops psc_dma_ops = {
295 	.open		= psc_dma_open,
296 	.close		= psc_dma_close,
297 	.hw_free	= psc_dma_hw_free,
298 	.ioctl		= snd_pcm_lib_ioctl,
299 	.pointer	= psc_dma_pointer,
300 	.trigger	= psc_dma_trigger,
301 	.hw_params	= psc_dma_hw_params,
302 };
303 
304 static int psc_dma_new(struct snd_soc_pcm_runtime *rtd)
305 {
306 	struct snd_card *card = rtd->card->snd_card;
307 	struct snd_soc_dai *dai = rtd->cpu_dai;
308 	struct snd_pcm *pcm = rtd->pcm;
309 	struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(rtd->cpu_dai);
310 	size_t size = psc_dma_hardware.buffer_bytes_max;
311 	int rc;
312 
313 	dev_dbg(rtd->platform->dev, "psc_dma_new(card=%p, dai=%p, pcm=%p)\n",
314 		card, dai, pcm);
315 
316 	rc = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
317 	if (rc)
318 		return rc;
319 
320 	if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
321 		rc = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, pcm->card->dev,
322 				size, &pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream->dma_buffer);
323 		if (rc)
324 			goto playback_alloc_err;
325 	}
326 
327 	if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
328 		rc = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, pcm->card->dev,
329 				size, &pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream->dma_buffer);
330 		if (rc)
331 			goto capture_alloc_err;
332 	}
333 
334 	if (rtd->codec->ac97)
335 		rtd->codec->ac97->private_data = psc_dma;
336 
337 	return 0;
338 
339  capture_alloc_err:
340 	if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
341 		snd_dma_free_pages(&pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream->dma_buffer);
342 
343  playback_alloc_err:
344 	dev_err(card->dev, "Cannot allocate buffer(s)\n");
345 
346 	return -ENOMEM;
347 }
348 
349 static void psc_dma_free(struct snd_pcm *pcm)
350 {
351 	struct snd_soc_pcm_runtime *rtd = pcm->private_data;
352 	struct snd_pcm_substream *substream;
353 	int stream;
354 
355 	dev_dbg(rtd->platform->dev, "psc_dma_free(pcm=%p)\n", pcm);
356 
357 	for (stream = 0; stream < 2; stream++) {
358 		substream = pcm->streams[stream].substream;
359 		if (substream) {
360 			snd_dma_free_pages(&substream->dma_buffer);
361 			substream->dma_buffer.area = NULL;
362 			substream->dma_buffer.addr = 0;
363 		}
364 	}
365 }
366 
367 static struct snd_soc_platform_driver mpc5200_audio_dma_platform = {
368 	.ops		= &psc_dma_ops,
369 	.pcm_new	= &psc_dma_new,
370 	.pcm_free	= &psc_dma_free,
371 };
372 
373 int mpc5200_audio_dma_create(struct platform_device *op)
374 {
375 	phys_addr_t fifo;
376 	struct psc_dma *psc_dma;
377 	struct resource res;
378 	int size, irq, rc;
379 	const __be32 *prop;
380 	void __iomem *regs;
381 	int ret;
382 
383 	/* Fetch the registers and IRQ of the PSC */
384 	irq = irq_of_parse_and_map(op->dev.of_node, 0);
385 	if (of_address_to_resource(op->dev.of_node, 0, &res)) {
386 		dev_err(&op->dev, "Missing reg property\n");
387 		return -ENODEV;
388 	}
389 	regs = ioremap(res.start, resource_size(&res));
390 	if (!regs) {
391 		dev_err(&op->dev, "Could not map registers\n");
392 		return -ENODEV;
393 	}
394 
395 	/* Allocate and initialize the driver private data */
396 	psc_dma = kzalloc(sizeof *psc_dma, GFP_KERNEL);
397 	if (!psc_dma) {
398 		ret = -ENOMEM;
399 		goto out_unmap;
400 	}
401 
402 	/* Get the PSC ID */
403 	prop = of_get_property(op->dev.of_node, "cell-index", &size);
404 	if (!prop || size < sizeof *prop) {
405 		ret = -ENODEV;
406 		goto out_free;
407 	}
408 
409 	spin_lock_init(&psc_dma->lock);
410 	mutex_init(&psc_dma->mutex);
411 	psc_dma->id = be32_to_cpu(*prop);
412 	psc_dma->irq = irq;
413 	psc_dma->psc_regs = regs;
414 	psc_dma->fifo_regs = regs + sizeof *psc_dma->psc_regs;
415 	psc_dma->dev = &op->dev;
416 	psc_dma->playback.psc_dma = psc_dma;
417 	psc_dma->capture.psc_dma = psc_dma;
418 	snprintf(psc_dma->name, sizeof psc_dma->name, "PSC%u", psc_dma->id);
419 
420 	/* Find the address of the fifo data registers and setup the
421 	 * DMA tasks */
422 	fifo = res.start + offsetof(struct mpc52xx_psc, buffer.buffer_32);
423 	psc_dma->capture.bcom_task =
424 		bcom_psc_gen_bd_rx_init(psc_dma->id, 10, fifo, 512);
425 	psc_dma->playback.bcom_task =
426 		bcom_psc_gen_bd_tx_init(psc_dma->id, 10, fifo);
427 	if (!psc_dma->capture.bcom_task ||
428 	    !psc_dma->playback.bcom_task) {
429 		dev_err(&op->dev, "Could not allocate bestcomm tasks\n");
430 		ret = -ENODEV;
431 		goto out_free;
432 	}
433 
434 	/* Disable all interrupts and reset the PSC */
435 	out_be16(&psc_dma->psc_regs->isr_imr.imr, psc_dma->imr);
436 	 /* reset receiver */
437 	out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_RST_RX);
438 	 /* reset transmitter */
439 	out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_RST_TX);
440 	 /* reset error */
441 	out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_RST_ERR_STAT);
442 	 /* reset mode */
443 	out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_SEL_MODE_REG_1);
444 
445 	/* Set up mode register;
446 	 * First write: RxRdy (FIFO Alarm) generates rx FIFO irq
447 	 * Second write: register Normal mode for non loopback
448 	 */
449 	out_8(&psc_dma->psc_regs->mode, 0);
450 	out_8(&psc_dma->psc_regs->mode, 0);
451 
452 	/* Set the TX and RX fifo alarm thresholds */
453 	out_be16(&psc_dma->fifo_regs->rfalarm, 0x100);
454 	out_8(&psc_dma->fifo_regs->rfcntl, 0x4);
455 	out_be16(&psc_dma->fifo_regs->tfalarm, 0x100);
456 	out_8(&psc_dma->fifo_regs->tfcntl, 0x7);
457 
458 	/* Lookup the IRQ numbers */
459 	psc_dma->playback.irq =
460 		bcom_get_task_irq(psc_dma->playback.bcom_task);
461 	psc_dma->capture.irq =
462 		bcom_get_task_irq(psc_dma->capture.bcom_task);
463 
464 	rc = request_irq(psc_dma->irq, &psc_dma_status_irq, IRQF_SHARED,
465 			 "psc-dma-status", psc_dma);
466 	rc |= request_irq(psc_dma->capture.irq, &psc_dma_bcom_irq, IRQF_SHARED,
467 			  "psc-dma-capture", &psc_dma->capture);
468 	rc |= request_irq(psc_dma->playback.irq, &psc_dma_bcom_irq, IRQF_SHARED,
469 			  "psc-dma-playback", &psc_dma->playback);
470 	if (rc) {
471 		ret = -ENODEV;
472 		goto out_irq;
473 	}
474 
475 	/* Save what we've done so it can be found again later */
476 	dev_set_drvdata(&op->dev, psc_dma);
477 
478 	/* Tell the ASoC OF helpers about it */
479 	return snd_soc_register_platform(&op->dev, &mpc5200_audio_dma_platform);
480 out_irq:
481 	free_irq(psc_dma->irq, psc_dma);
482 	free_irq(psc_dma->capture.irq, &psc_dma->capture);
483 	free_irq(psc_dma->playback.irq, &psc_dma->playback);
484 out_free:
485 	kfree(psc_dma);
486 out_unmap:
487 	iounmap(regs);
488 	return ret;
489 }
490 EXPORT_SYMBOL_GPL(mpc5200_audio_dma_create);
491 
492 int mpc5200_audio_dma_destroy(struct platform_device *op)
493 {
494 	struct psc_dma *psc_dma = dev_get_drvdata(&op->dev);
495 
496 	dev_dbg(&op->dev, "mpc5200_audio_dma_destroy()\n");
497 
498 	snd_soc_unregister_platform(&op->dev);
499 
500 	bcom_gen_bd_rx_release(psc_dma->capture.bcom_task);
501 	bcom_gen_bd_tx_release(psc_dma->playback.bcom_task);
502 
503 	/* Release irqs */
504 	free_irq(psc_dma->irq, psc_dma);
505 	free_irq(psc_dma->capture.irq, &psc_dma->capture);
506 	free_irq(psc_dma->playback.irq, &psc_dma->playback);
507 
508 	iounmap(psc_dma->psc_regs);
509 	kfree(psc_dma);
510 	dev_set_drvdata(&op->dev, NULL);
511 
512 	return 0;
513 }
514 EXPORT_SYMBOL_GPL(mpc5200_audio_dma_destroy);
515 
516 MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
517 MODULE_DESCRIPTION("Freescale MPC5200 PSC in DMA mode ASoC Driver");
518 MODULE_LICENSE("GPL");
519