xref: /openbmc/linux/sound/soc/fsl/mpc5200_dma.c (revision feac8c8b)
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 	.period_bytes_max	= 1024 * 1024,
204 	.period_bytes_min	= 32,
205 	.periods_min		= 2,
206 	.periods_max		= 256,
207 	.buffer_bytes_max	= 2 * 1024 * 1024,
208 	.fifo_size		= 512,
209 };
210 
211 static int psc_dma_open(struct snd_pcm_substream *substream)
212 {
213 	struct snd_pcm_runtime *runtime = substream->runtime;
214 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
215 	struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(rtd->cpu_dai);
216 	struct psc_dma_stream *s;
217 	int rc;
218 
219 	dev_dbg(psc_dma->dev, "psc_dma_open(substream=%p)\n", substream);
220 
221 	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
222 		s = &psc_dma->capture;
223 	else
224 		s = &psc_dma->playback;
225 
226 	snd_soc_set_runtime_hwparams(substream, &psc_dma_hardware);
227 
228 	rc = snd_pcm_hw_constraint_integer(runtime,
229 		SNDRV_PCM_HW_PARAM_PERIODS);
230 	if (rc < 0) {
231 		dev_err(substream->pcm->card->dev, "invalid buffer size\n");
232 		return rc;
233 	}
234 
235 	s->stream = substream;
236 	return 0;
237 }
238 
239 static int psc_dma_close(struct snd_pcm_substream *substream)
240 {
241 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
242 	struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(rtd->cpu_dai);
243 	struct psc_dma_stream *s;
244 
245 	dev_dbg(psc_dma->dev, "psc_dma_close(substream=%p)\n", substream);
246 
247 	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
248 		s = &psc_dma->capture;
249 	else
250 		s = &psc_dma->playback;
251 
252 	if (!psc_dma->playback.active &&
253 	    !psc_dma->capture.active) {
254 
255 		/* Disable all interrupts and reset the PSC */
256 		out_be16(&psc_dma->psc_regs->isr_imr.imr, psc_dma->imr);
257 		out_8(&psc_dma->psc_regs->command, 4 << 4); /* reset error */
258 	}
259 	s->stream = NULL;
260 	return 0;
261 }
262 
263 static snd_pcm_uframes_t
264 psc_dma_pointer(struct snd_pcm_substream *substream)
265 {
266 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
267 	struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(rtd->cpu_dai);
268 	struct psc_dma_stream *s;
269 	dma_addr_t count;
270 
271 	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
272 		s = &psc_dma->capture;
273 	else
274 		s = &psc_dma->playback;
275 
276 	count = s->period_current * s->period_bytes;
277 
278 	return bytes_to_frames(substream->runtime, count);
279 }
280 
281 static int
282 psc_dma_hw_params(struct snd_pcm_substream *substream,
283 			 struct snd_pcm_hw_params *params)
284 {
285 	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
286 
287 	return 0;
288 }
289 
290 static const struct snd_pcm_ops psc_dma_ops = {
291 	.open		= psc_dma_open,
292 	.close		= psc_dma_close,
293 	.hw_free	= psc_dma_hw_free,
294 	.ioctl		= snd_pcm_lib_ioctl,
295 	.pointer	= psc_dma_pointer,
296 	.trigger	= psc_dma_trigger,
297 	.hw_params	= psc_dma_hw_params,
298 };
299 
300 static int psc_dma_new(struct snd_soc_pcm_runtime *rtd)
301 {
302 	struct snd_card *card = rtd->card->snd_card;
303 	struct snd_soc_dai *dai = rtd->cpu_dai;
304 	struct snd_pcm *pcm = rtd->pcm;
305 	size_t size = psc_dma_hardware.buffer_bytes_max;
306 	int rc;
307 
308 	dev_dbg(rtd->platform->dev, "psc_dma_new(card=%p, dai=%p, pcm=%p)\n",
309 		card, dai, pcm);
310 
311 	rc = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
312 	if (rc)
313 		return rc;
314 
315 	if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
316 		rc = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, pcm->card->dev,
317 				size, &pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream->dma_buffer);
318 		if (rc)
319 			goto playback_alloc_err;
320 	}
321 
322 	if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
323 		rc = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, pcm->card->dev,
324 				size, &pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream->dma_buffer);
325 		if (rc)
326 			goto capture_alloc_err;
327 	}
328 
329 	return 0;
330 
331  capture_alloc_err:
332 	if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
333 		snd_dma_free_pages(&pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream->dma_buffer);
334 
335  playback_alloc_err:
336 	dev_err(card->dev, "Cannot allocate buffer(s)\n");
337 
338 	return -ENOMEM;
339 }
340 
341 static void psc_dma_free(struct snd_pcm *pcm)
342 {
343 	struct snd_soc_pcm_runtime *rtd = pcm->private_data;
344 	struct snd_pcm_substream *substream;
345 	int stream;
346 
347 	dev_dbg(rtd->platform->dev, "psc_dma_free(pcm=%p)\n", pcm);
348 
349 	for (stream = 0; stream < 2; stream++) {
350 		substream = pcm->streams[stream].substream;
351 		if (substream) {
352 			snd_dma_free_pages(&substream->dma_buffer);
353 			substream->dma_buffer.area = NULL;
354 			substream->dma_buffer.addr = 0;
355 		}
356 	}
357 }
358 
359 static const struct snd_soc_platform_driver mpc5200_audio_dma_platform = {
360 	.ops		= &psc_dma_ops,
361 	.pcm_new	= &psc_dma_new,
362 	.pcm_free	= &psc_dma_free,
363 };
364 
365 int mpc5200_audio_dma_create(struct platform_device *op)
366 {
367 	phys_addr_t fifo;
368 	struct psc_dma *psc_dma;
369 	struct resource res;
370 	int size, irq, rc;
371 	const __be32 *prop;
372 	void __iomem *regs;
373 	int ret;
374 
375 	/* Fetch the registers and IRQ of the PSC */
376 	irq = irq_of_parse_and_map(op->dev.of_node, 0);
377 	if (of_address_to_resource(op->dev.of_node, 0, &res)) {
378 		dev_err(&op->dev, "Missing reg property\n");
379 		return -ENODEV;
380 	}
381 	regs = ioremap(res.start, resource_size(&res));
382 	if (!regs) {
383 		dev_err(&op->dev, "Could not map registers\n");
384 		return -ENODEV;
385 	}
386 
387 	/* Allocate and initialize the driver private data */
388 	psc_dma = kzalloc(sizeof *psc_dma, GFP_KERNEL);
389 	if (!psc_dma) {
390 		ret = -ENOMEM;
391 		goto out_unmap;
392 	}
393 
394 	/* Get the PSC ID */
395 	prop = of_get_property(op->dev.of_node, "cell-index", &size);
396 	if (!prop || size < sizeof *prop) {
397 		ret = -ENODEV;
398 		goto out_free;
399 	}
400 
401 	spin_lock_init(&psc_dma->lock);
402 	mutex_init(&psc_dma->mutex);
403 	psc_dma->id = be32_to_cpu(*prop);
404 	psc_dma->irq = irq;
405 	psc_dma->psc_regs = regs;
406 	psc_dma->fifo_regs = regs + sizeof *psc_dma->psc_regs;
407 	psc_dma->dev = &op->dev;
408 	psc_dma->playback.psc_dma = psc_dma;
409 	psc_dma->capture.psc_dma = psc_dma;
410 	snprintf(psc_dma->name, sizeof psc_dma->name, "PSC%u", psc_dma->id);
411 
412 	/* Find the address of the fifo data registers and setup the
413 	 * DMA tasks */
414 	fifo = res.start + offsetof(struct mpc52xx_psc, buffer.buffer_32);
415 	psc_dma->capture.bcom_task =
416 		bcom_psc_gen_bd_rx_init(psc_dma->id, 10, fifo, 512);
417 	psc_dma->playback.bcom_task =
418 		bcom_psc_gen_bd_tx_init(psc_dma->id, 10, fifo);
419 	if (!psc_dma->capture.bcom_task ||
420 	    !psc_dma->playback.bcom_task) {
421 		dev_err(&op->dev, "Could not allocate bestcomm tasks\n");
422 		ret = -ENODEV;
423 		goto out_free;
424 	}
425 
426 	/* Disable all interrupts and reset the PSC */
427 	out_be16(&psc_dma->psc_regs->isr_imr.imr, psc_dma->imr);
428 	 /* reset receiver */
429 	out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_RST_RX);
430 	 /* reset transmitter */
431 	out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_RST_TX);
432 	 /* reset error */
433 	out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_RST_ERR_STAT);
434 	 /* reset mode */
435 	out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_SEL_MODE_REG_1);
436 
437 	/* Set up mode register;
438 	 * First write: RxRdy (FIFO Alarm) generates rx FIFO irq
439 	 * Second write: register Normal mode for non loopback
440 	 */
441 	out_8(&psc_dma->psc_regs->mode, 0);
442 	out_8(&psc_dma->psc_regs->mode, 0);
443 
444 	/* Set the TX and RX fifo alarm thresholds */
445 	out_be16(&psc_dma->fifo_regs->rfalarm, 0x100);
446 	out_8(&psc_dma->fifo_regs->rfcntl, 0x4);
447 	out_be16(&psc_dma->fifo_regs->tfalarm, 0x100);
448 	out_8(&psc_dma->fifo_regs->tfcntl, 0x7);
449 
450 	/* Lookup the IRQ numbers */
451 	psc_dma->playback.irq =
452 		bcom_get_task_irq(psc_dma->playback.bcom_task);
453 	psc_dma->capture.irq =
454 		bcom_get_task_irq(psc_dma->capture.bcom_task);
455 
456 	rc = request_irq(psc_dma->irq, &psc_dma_status_irq, IRQF_SHARED,
457 			 "psc-dma-status", psc_dma);
458 	rc |= request_irq(psc_dma->capture.irq, &psc_dma_bcom_irq, IRQF_SHARED,
459 			  "psc-dma-capture", &psc_dma->capture);
460 	rc |= request_irq(psc_dma->playback.irq, &psc_dma_bcom_irq, IRQF_SHARED,
461 			  "psc-dma-playback", &psc_dma->playback);
462 	if (rc) {
463 		ret = -ENODEV;
464 		goto out_irq;
465 	}
466 
467 	/* Save what we've done so it can be found again later */
468 	dev_set_drvdata(&op->dev, psc_dma);
469 
470 	/* Tell the ASoC OF helpers about it */
471 	return snd_soc_register_platform(&op->dev, &mpc5200_audio_dma_platform);
472 out_irq:
473 	free_irq(psc_dma->irq, psc_dma);
474 	free_irq(psc_dma->capture.irq, &psc_dma->capture);
475 	free_irq(psc_dma->playback.irq, &psc_dma->playback);
476 out_free:
477 	kfree(psc_dma);
478 out_unmap:
479 	iounmap(regs);
480 	return ret;
481 }
482 EXPORT_SYMBOL_GPL(mpc5200_audio_dma_create);
483 
484 int mpc5200_audio_dma_destroy(struct platform_device *op)
485 {
486 	struct psc_dma *psc_dma = dev_get_drvdata(&op->dev);
487 
488 	dev_dbg(&op->dev, "mpc5200_audio_dma_destroy()\n");
489 
490 	snd_soc_unregister_platform(&op->dev);
491 
492 	bcom_gen_bd_rx_release(psc_dma->capture.bcom_task);
493 	bcom_gen_bd_tx_release(psc_dma->playback.bcom_task);
494 
495 	/* Release irqs */
496 	free_irq(psc_dma->irq, psc_dma);
497 	free_irq(psc_dma->capture.irq, &psc_dma->capture);
498 	free_irq(psc_dma->playback.irq, &psc_dma->playback);
499 
500 	iounmap(psc_dma->psc_regs);
501 	kfree(psc_dma);
502 	dev_set_drvdata(&op->dev, NULL);
503 
504 	return 0;
505 }
506 EXPORT_SYMBOL_GPL(mpc5200_audio_dma_destroy);
507 
508 MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
509 MODULE_DESCRIPTION("Freescale MPC5200 PSC in DMA mode ASoC Driver");
510 MODULE_LICENSE("GPL");
511