xref: /openbmc/linux/sound/soc/fsl/mpc5200_dma.c (revision 565d76cb)
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/slab.h>
12 #include <linux/of_platform.h>
13 
14 #include <sound/soc.h>
15 
16 #include <sysdev/bestcomm/bestcomm.h>
17 #include <sysdev/bestcomm/gen_bd.h>
18 #include <asm/mpc52xx_psc.h>
19 
20 #include "mpc5200_dma.h"
21 
22 /*
23  * Interrupt handlers
24  */
25 static irqreturn_t psc_dma_status_irq(int irq, void *_psc_dma)
26 {
27 	struct psc_dma *psc_dma = _psc_dma;
28 	struct mpc52xx_psc __iomem *regs = psc_dma->psc_regs;
29 	u16 isr;
30 
31 	isr = in_be16(&regs->mpc52xx_psc_isr);
32 
33 	/* Playback underrun error */
34 	if (psc_dma->playback.active && (isr & MPC52xx_PSC_IMR_TXEMP))
35 		psc_dma->stats.underrun_count++;
36 
37 	/* Capture overrun error */
38 	if (psc_dma->capture.active && (isr & MPC52xx_PSC_IMR_ORERR))
39 		psc_dma->stats.overrun_count++;
40 
41 	out_8(&regs->command, MPC52xx_PSC_RST_ERR_STAT);
42 
43 	return IRQ_HANDLED;
44 }
45 
46 /**
47  * psc_dma_bcom_enqueue_next_buffer - Enqueue another audio buffer
48  * @s: pointer to stream private data structure
49  *
50  * Enqueues another audio period buffer into the bestcomm queue.
51  *
52  * Note: The routine must only be called when there is space available in
53  * the queue.  Otherwise the enqueue will fail and the audio ring buffer
54  * will get out of sync
55  */
56 static void psc_dma_bcom_enqueue_next_buffer(struct psc_dma_stream *s)
57 {
58 	struct bcom_bd *bd;
59 
60 	/* Prepare and enqueue the next buffer descriptor */
61 	bd = bcom_prepare_next_buffer(s->bcom_task);
62 	bd->status = s->period_bytes;
63 	bd->data[0] = s->runtime->dma_addr + (s->period_next * s->period_bytes);
64 	bcom_submit_next_buffer(s->bcom_task, NULL);
65 
66 	/* Update for next period */
67 	s->period_next = (s->period_next + 1) % s->runtime->periods;
68 }
69 
70 /* Bestcomm DMA irq handler */
71 static irqreturn_t psc_dma_bcom_irq(int irq, void *_psc_dma_stream)
72 {
73 	struct psc_dma_stream *s = _psc_dma_stream;
74 
75 	spin_lock(&s->psc_dma->lock);
76 	/* For each finished period, dequeue the completed period buffer
77 	 * and enqueue a new one in it's place. */
78 	while (bcom_buffer_done(s->bcom_task)) {
79 		bcom_retrieve_buffer(s->bcom_task, NULL, NULL);
80 
81 		s->period_current = (s->period_current+1) % s->runtime->periods;
82 		s->period_count++;
83 
84 		psc_dma_bcom_enqueue_next_buffer(s);
85 	}
86 	spin_unlock(&s->psc_dma->lock);
87 
88 	/* If the stream is active, then also inform the PCM middle layer
89 	 * of the period finished event. */
90 	if (s->active)
91 		snd_pcm_period_elapsed(s->stream);
92 
93 	return IRQ_HANDLED;
94 }
95 
96 static int psc_dma_hw_free(struct snd_pcm_substream *substream)
97 {
98 	snd_pcm_set_runtime_buffer(substream, NULL);
99 	return 0;
100 }
101 
102 /**
103  * psc_dma_trigger: start and stop the DMA transfer.
104  *
105  * This function is called by ALSA to start, stop, pause, and resume the DMA
106  * transfer of data.
107  */
108 static int psc_dma_trigger(struct snd_pcm_substream *substream, int cmd)
109 {
110 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
111 	struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(rtd->cpu_dai);
112 	struct snd_pcm_runtime *runtime = substream->runtime;
113 	struct psc_dma_stream *s = to_psc_dma_stream(substream, psc_dma);
114 	struct mpc52xx_psc __iomem *regs = psc_dma->psc_regs;
115 	u16 imr;
116 	unsigned long flags;
117 	int i;
118 
119 	switch (cmd) {
120 	case SNDRV_PCM_TRIGGER_START:
121 		dev_dbg(psc_dma->dev, "START: stream=%i fbits=%u ps=%u #p=%u\n",
122 			substream->pstr->stream, runtime->frame_bits,
123 			(int)runtime->period_size, runtime->periods);
124 		s->period_bytes = frames_to_bytes(runtime,
125 						  runtime->period_size);
126 		s->period_next = 0;
127 		s->period_current = 0;
128 		s->active = 1;
129 		s->period_count = 0;
130 		s->runtime = runtime;
131 
132 		/* Fill up the bestcomm bd queue and enable DMA.
133 		 * This will begin filling the PSC's fifo.
134 		 */
135 		spin_lock_irqsave(&psc_dma->lock, flags);
136 
137 		if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
138 			bcom_gen_bd_rx_reset(s->bcom_task);
139 		else
140 			bcom_gen_bd_tx_reset(s->bcom_task);
141 
142 		for (i = 0; i < runtime->periods; i++)
143 			if (!bcom_queue_full(s->bcom_task))
144 				psc_dma_bcom_enqueue_next_buffer(s);
145 
146 		bcom_enable(s->bcom_task);
147 		spin_unlock_irqrestore(&psc_dma->lock, flags);
148 
149 		out_8(&regs->command, MPC52xx_PSC_RST_ERR_STAT);
150 
151 		break;
152 
153 	case SNDRV_PCM_TRIGGER_STOP:
154 		dev_dbg(psc_dma->dev, "STOP: stream=%i periods_count=%i\n",
155 			substream->pstr->stream, s->period_count);
156 		s->active = 0;
157 
158 		spin_lock_irqsave(&psc_dma->lock, flags);
159 		bcom_disable(s->bcom_task);
160 		if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
161 			bcom_gen_bd_rx_reset(s->bcom_task);
162 		else
163 			bcom_gen_bd_tx_reset(s->bcom_task);
164 		spin_unlock_irqrestore(&psc_dma->lock, flags);
165 
166 		break;
167 
168 	default:
169 		dev_dbg(psc_dma->dev, "unhandled trigger: stream=%i cmd=%i\n",
170 			substream->pstr->stream, cmd);
171 		return -EINVAL;
172 	}
173 
174 	/* Update interrupt enable settings */
175 	imr = 0;
176 	if (psc_dma->playback.active)
177 		imr |= MPC52xx_PSC_IMR_TXEMP;
178 	if (psc_dma->capture.active)
179 		imr |= MPC52xx_PSC_IMR_ORERR;
180 	out_be16(&regs->isr_imr.imr, psc_dma->imr | imr);
181 
182 	return 0;
183 }
184 
185 
186 /* ---------------------------------------------------------------------
187  * The PSC DMA 'ASoC platform' driver
188  *
189  * Can be referenced by an 'ASoC machine' driver
190  * This driver only deals with the audio bus; it doesn't have any
191  * interaction with the attached codec
192  */
193 
194 static const struct snd_pcm_hardware psc_dma_hardware = {
195 	.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
196 		SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
197 		SNDRV_PCM_INFO_BATCH,
198 	.formats = SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_BE |
199 		SNDRV_PCM_FMTBIT_S24_BE | SNDRV_PCM_FMTBIT_S32_BE,
200 	.rate_min = 8000,
201 	.rate_max = 48000,
202 	.channels_min = 1,
203 	.channels_max = 2,
204 	.period_bytes_max	= 1024 * 1024,
205 	.period_bytes_min	= 32,
206 	.periods_min		= 2,
207 	.periods_max		= 256,
208 	.buffer_bytes_max	= 2 * 1024 * 1024,
209 	.fifo_size		= 512,
210 };
211 
212 static int psc_dma_open(struct snd_pcm_substream *substream)
213 {
214 	struct snd_pcm_runtime *runtime = substream->runtime;
215 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
216 	struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(rtd->cpu_dai);
217 	struct psc_dma_stream *s;
218 	int rc;
219 
220 	dev_dbg(psc_dma->dev, "psc_dma_open(substream=%p)\n", substream);
221 
222 	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
223 		s = &psc_dma->capture;
224 	else
225 		s = &psc_dma->playback;
226 
227 	snd_soc_set_runtime_hwparams(substream, &psc_dma_hardware);
228 
229 	rc = snd_pcm_hw_constraint_integer(runtime,
230 		SNDRV_PCM_HW_PARAM_PERIODS);
231 	if (rc < 0) {
232 		dev_err(substream->pcm->card->dev, "invalid buffer size\n");
233 		return rc;
234 	}
235 
236 	s->stream = substream;
237 	return 0;
238 }
239 
240 static int psc_dma_close(struct snd_pcm_substream *substream)
241 {
242 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
243 	struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(rtd->cpu_dai);
244 	struct psc_dma_stream *s;
245 
246 	dev_dbg(psc_dma->dev, "psc_dma_close(substream=%p)\n", substream);
247 
248 	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
249 		s = &psc_dma->capture;
250 	else
251 		s = &psc_dma->playback;
252 
253 	if (!psc_dma->playback.active &&
254 	    !psc_dma->capture.active) {
255 
256 		/* Disable all interrupts and reset the PSC */
257 		out_be16(&psc_dma->psc_regs->isr_imr.imr, psc_dma->imr);
258 		out_8(&psc_dma->psc_regs->command, 4 << 4); /* reset error */
259 	}
260 	s->stream = NULL;
261 	return 0;
262 }
263 
264 static snd_pcm_uframes_t
265 psc_dma_pointer(struct snd_pcm_substream *substream)
266 {
267 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
268 	struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(rtd->cpu_dai);
269 	struct psc_dma_stream *s;
270 	dma_addr_t count;
271 
272 	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
273 		s = &psc_dma->capture;
274 	else
275 		s = &psc_dma->playback;
276 
277 	count = s->period_current * s->period_bytes;
278 
279 	return bytes_to_frames(substream->runtime, count);
280 }
281 
282 static int
283 psc_dma_hw_params(struct snd_pcm_substream *substream,
284 			 struct snd_pcm_hw_params *params)
285 {
286 	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
287 
288 	return 0;
289 }
290 
291 static struct snd_pcm_ops psc_dma_ops = {
292 	.open		= psc_dma_open,
293 	.close		= psc_dma_close,
294 	.hw_free	= psc_dma_hw_free,
295 	.ioctl		= snd_pcm_lib_ioctl,
296 	.pointer	= psc_dma_pointer,
297 	.trigger	= psc_dma_trigger,
298 	.hw_params	= psc_dma_hw_params,
299 };
300 
301 static u64 psc_dma_dmamask = 0xffffffff;
302 static int psc_dma_new(struct snd_card *card, struct snd_soc_dai *dai,
303 			   struct snd_pcm *pcm)
304 {
305 	struct snd_soc_pcm_runtime *rtd = pcm->private_data;
306 	struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(rtd->cpu_dai);
307 	size_t size = psc_dma_hardware.buffer_bytes_max;
308 	int rc = 0;
309 
310 	dev_dbg(rtd->platform->dev, "psc_dma_new(card=%p, dai=%p, pcm=%p)\n",
311 		card, dai, pcm);
312 
313 	if (!card->dev->dma_mask)
314 		card->dev->dma_mask = &psc_dma_dmamask;
315 	if (!card->dev->coherent_dma_mask)
316 		card->dev->coherent_dma_mask = 0xffffffff;
317 
318 	if (pcm->streams[0].substream) {
319 		rc = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, pcm->card->dev,
320 				size, &pcm->streams[0].substream->dma_buffer);
321 		if (rc)
322 			goto playback_alloc_err;
323 	}
324 
325 	if (pcm->streams[1].substream) {
326 		rc = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, pcm->card->dev,
327 				size, &pcm->streams[1].substream->dma_buffer);
328 		if (rc)
329 			goto capture_alloc_err;
330 	}
331 
332 	if (rtd->codec->ac97)
333 		rtd->codec->ac97->private_data = psc_dma;
334 
335 	return 0;
336 
337  capture_alloc_err:
338 	if (pcm->streams[0].substream)
339 		snd_dma_free_pages(&pcm->streams[0].substream->dma_buffer);
340 
341  playback_alloc_err:
342 	dev_err(card->dev, "Cannot allocate buffer(s)\n");
343 
344 	return -ENOMEM;
345 }
346 
347 static void psc_dma_free(struct snd_pcm *pcm)
348 {
349 	struct snd_soc_pcm_runtime *rtd = pcm->private_data;
350 	struct snd_pcm_substream *substream;
351 	int stream;
352 
353 	dev_dbg(rtd->platform->dev, "psc_dma_free(pcm=%p)\n", pcm);
354 
355 	for (stream = 0; stream < 2; stream++) {
356 		substream = pcm->streams[stream].substream;
357 		if (substream) {
358 			snd_dma_free_pages(&substream->dma_buffer);
359 			substream->dma_buffer.area = NULL;
360 			substream->dma_buffer.addr = 0;
361 		}
362 	}
363 }
364 
365 static struct snd_soc_platform_driver mpc5200_audio_dma_platform = {
366 	.ops		= &psc_dma_ops,
367 	.pcm_new	= &psc_dma_new,
368 	.pcm_free	= &psc_dma_free,
369 };
370 
371 static int mpc5200_hpcd_probe(struct of_device *op)
372 {
373 	phys_addr_t fifo;
374 	struct psc_dma *psc_dma;
375 	struct resource res;
376 	int size, irq, rc;
377 	const __be32 *prop;
378 	void __iomem *regs;
379 	int ret;
380 
381 	/* Fetch the registers and IRQ of the PSC */
382 	irq = irq_of_parse_and_map(op->dev.of_node, 0);
383 	if (of_address_to_resource(op->dev.of_node, 0, &res)) {
384 		dev_err(&op->dev, "Missing reg property\n");
385 		return -ENODEV;
386 	}
387 	regs = ioremap(res.start, 1 + res.end - res.start);
388 	if (!regs) {
389 		dev_err(&op->dev, "Could not map registers\n");
390 		return -ENODEV;
391 	}
392 
393 	/* Allocate and initialize the driver private data */
394 	psc_dma = kzalloc(sizeof *psc_dma, GFP_KERNEL);
395 	if (!psc_dma) {
396 		ret = -ENOMEM;
397 		goto out_unmap;
398 	}
399 
400 	/* Get the PSC ID */
401 	prop = of_get_property(op->dev.of_node, "cell-index", &size);
402 	if (!prop || size < sizeof *prop) {
403 		ret = -ENODEV;
404 		goto out_free;
405 	}
406 
407 	spin_lock_init(&psc_dma->lock);
408 	mutex_init(&psc_dma->mutex);
409 	psc_dma->id = be32_to_cpu(*prop);
410 	psc_dma->irq = irq;
411 	psc_dma->psc_regs = regs;
412 	psc_dma->fifo_regs = regs + sizeof *psc_dma->psc_regs;
413 	psc_dma->dev = &op->dev;
414 	psc_dma->playback.psc_dma = psc_dma;
415 	psc_dma->capture.psc_dma = psc_dma;
416 	snprintf(psc_dma->name, sizeof psc_dma->name, "PSC%u", psc_dma->id);
417 
418 	/* Find the address of the fifo data registers and setup the
419 	 * DMA tasks */
420 	fifo = res.start + offsetof(struct mpc52xx_psc, buffer.buffer_32);
421 	psc_dma->capture.bcom_task =
422 		bcom_psc_gen_bd_rx_init(psc_dma->id, 10, fifo, 512);
423 	psc_dma->playback.bcom_task =
424 		bcom_psc_gen_bd_tx_init(psc_dma->id, 10, fifo);
425 	if (!psc_dma->capture.bcom_task ||
426 	    !psc_dma->playback.bcom_task) {
427 		dev_err(&op->dev, "Could not allocate bestcomm tasks\n");
428 		ret = -ENODEV;
429 		goto out_free;
430 	}
431 
432 	/* Disable all interrupts and reset the PSC */
433 	out_be16(&psc_dma->psc_regs->isr_imr.imr, psc_dma->imr);
434 	 /* reset receiver */
435 	out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_RST_RX);
436 	 /* reset transmitter */
437 	out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_RST_TX);
438 	 /* reset error */
439 	out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_RST_ERR_STAT);
440 	 /* reset mode */
441 	out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_SEL_MODE_REG_1);
442 
443 	/* Set up mode register;
444 	 * First write: RxRdy (FIFO Alarm) generates rx FIFO irq
445 	 * Second write: register Normal mode for non loopback
446 	 */
447 	out_8(&psc_dma->psc_regs->mode, 0);
448 	out_8(&psc_dma->psc_regs->mode, 0);
449 
450 	/* Set the TX and RX fifo alarm thresholds */
451 	out_be16(&psc_dma->fifo_regs->rfalarm, 0x100);
452 	out_8(&psc_dma->fifo_regs->rfcntl, 0x4);
453 	out_be16(&psc_dma->fifo_regs->tfalarm, 0x100);
454 	out_8(&psc_dma->fifo_regs->tfcntl, 0x7);
455 
456 	/* Lookup the IRQ numbers */
457 	psc_dma->playback.irq =
458 		bcom_get_task_irq(psc_dma->playback.bcom_task);
459 	psc_dma->capture.irq =
460 		bcom_get_task_irq(psc_dma->capture.bcom_task);
461 
462 	rc = request_irq(psc_dma->irq, &psc_dma_status_irq, IRQF_SHARED,
463 			 "psc-dma-status", psc_dma);
464 	rc |= request_irq(psc_dma->capture.irq, &psc_dma_bcom_irq, IRQF_SHARED,
465 			  "psc-dma-capture", &psc_dma->capture);
466 	rc |= request_irq(psc_dma->playback.irq, &psc_dma_bcom_irq, IRQF_SHARED,
467 			  "psc-dma-playback", &psc_dma->playback);
468 	if (rc) {
469 		ret = -ENODEV;
470 		goto out_irq;
471 	}
472 
473 	/* Save what we've done so it can be found again later */
474 	dev_set_drvdata(&op->dev, psc_dma);
475 
476 	/* Tell the ASoC OF helpers about it */
477 	return snd_soc_register_platform(&op->dev, &mpc5200_audio_dma_platform);
478 out_irq:
479 	free_irq(psc_dma->irq, psc_dma);
480 	free_irq(psc_dma->capture.irq, &psc_dma->capture);
481 	free_irq(psc_dma->playback.irq, &psc_dma->playback);
482 out_free:
483 	kfree(psc_dma);
484 out_unmap:
485 	iounmap(regs);
486 	return ret;
487 }
488 
489 static int mpc5200_hpcd_remove(struct of_device *op)
490 {
491 	struct psc_dma *psc_dma = dev_get_drvdata(&op->dev);
492 
493 	dev_dbg(&op->dev, "mpc5200_audio_dma_destroy()\n");
494 
495 	snd_soc_unregister_platform(&op->dev);
496 
497 	bcom_gen_bd_rx_release(psc_dma->capture.bcom_task);
498 	bcom_gen_bd_tx_release(psc_dma->playback.bcom_task);
499 
500 	/* Release irqs */
501 	free_irq(psc_dma->irq, psc_dma);
502 	free_irq(psc_dma->capture.irq, &psc_dma->capture);
503 	free_irq(psc_dma->playback.irq, &psc_dma->playback);
504 
505 	iounmap(psc_dma->psc_regs);
506 	kfree(psc_dma);
507 	dev_set_drvdata(&op->dev, NULL);
508 
509 	return 0;
510 }
511 
512 static struct of_device_id mpc5200_hpcd_match[] = {
513 	{ .compatible = "fsl,mpc5200-pcm", },
514 	{}
515 };
516 MODULE_DEVICE_TABLE(of, mpc5200_hpcd_match);
517 
518 static struct platform_driver mpc5200_hpcd_of_driver = {
519 	.probe		= mpc5200_hpcd_probe,
520 	.remove		= mpc5200_hpcd_remove,
521 	.dev = {
522 		.owner		= THIS_MODULE,
523 		.name		= "mpc5200-pcm-audio",
524 		.of_match_table    = mpc5200_hpcd_match,
525 	}
526 };
527 
528 static int __init mpc5200_hpcd_init(void)
529 {
530 	return platform_driver_register(&mpc5200_hpcd_of_driver);
531 }
532 module_init(mpc5200_hpcd_init);
533 
534 static void __exit mpc5200_hpcd_exit(void)
535 {
536 	platform_driver_unregister(&mpc5200_hpcd_of_driver);
537 }
538 module_exit(mpc5200_hpcd_exit);
539 
540 MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
541 MODULE_DESCRIPTION("Freescale MPC5200 PSC in DMA mode ASoC Driver");
542 MODULE_LICENSE("GPL");
543