1// SPDX-License-Identifier: GPL-2.0-only
2//
3// Freescale MPC5200 PSC DMA
4// ALSA SoC Platform driver
5//
6// Copyright (C) 2008 Secret Lab Technologies Ltd.
7// Copyright (C) 2009 Jon Smirl, Digispeaker
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#define DRV_NAME "mpc5200_dma"
26
27/*
28 * Interrupt handlers
29 */
30static irqreturn_t psc_dma_status_irq(int irq, void *_psc_dma)
31{
32	struct psc_dma *psc_dma = _psc_dma;
33	struct mpc52xx_psc __iomem *regs = psc_dma->psc_regs;
34	u16 isr;
35
36	isr = in_be16(&regs->mpc52xx_psc_isr);
37
38	/* Playback underrun error */
39	if (psc_dma->playback.active && (isr & MPC52xx_PSC_IMR_TXEMP))
40		psc_dma->stats.underrun_count++;
41
42	/* Capture overrun error */
43	if (psc_dma->capture.active && (isr & MPC52xx_PSC_IMR_ORERR))
44		psc_dma->stats.overrun_count++;
45
46	out_8(&regs->command, MPC52xx_PSC_RST_ERR_STAT);
47
48	return IRQ_HANDLED;
49}
50
51/**
52 * psc_dma_bcom_enqueue_next_buffer - Enqueue another audio buffer
53 * @s: pointer to stream private data structure
54 *
55 * Enqueues another audio period buffer into the bestcomm queue.
56 *
57 * Note: The routine must only be called when there is space available in
58 * the queue.  Otherwise the enqueue will fail and the audio ring buffer
59 * will get out of sync
60 */
61static void psc_dma_bcom_enqueue_next_buffer(struct psc_dma_stream *s)
62{
63	struct bcom_bd *bd;
64
65	/* Prepare and enqueue the next buffer descriptor */
66	bd = bcom_prepare_next_buffer(s->bcom_task);
67	bd->status = s->period_bytes;
68	bd->data[0] = s->runtime->dma_addr + (s->period_next * s->period_bytes);
69	bcom_submit_next_buffer(s->bcom_task, NULL);
70
71	/* Update for next period */
72	s->period_next = (s->period_next + 1) % s->runtime->periods;
73}
74
75/* Bestcomm DMA irq handler */
76static irqreturn_t psc_dma_bcom_irq(int irq, void *_psc_dma_stream)
77{
78	struct psc_dma_stream *s = _psc_dma_stream;
79
80	spin_lock(&s->psc_dma->lock);
81	/* For each finished period, dequeue the completed period buffer
82	 * and enqueue a new one in it's place. */
83	while (bcom_buffer_done(s->bcom_task)) {
84		bcom_retrieve_buffer(s->bcom_task, NULL, NULL);
85
86		s->period_current = (s->period_current+1) % s->runtime->periods;
87		s->period_count++;
88
89		psc_dma_bcom_enqueue_next_buffer(s);
90	}
91	spin_unlock(&s->psc_dma->lock);
92
93	/* If the stream is active, then also inform the PCM middle layer
94	 * of the period finished event. */
95	if (s->active)
96		snd_pcm_period_elapsed(s->stream);
97
98	return IRQ_HANDLED;
99}
100
101static int psc_dma_hw_free(struct snd_soc_component *component,
102			   struct snd_pcm_substream *substream)
103{
104	snd_pcm_set_runtime_buffer(substream, NULL);
105	return 0;
106}
107
108/**
109 * psc_dma_trigger: start and stop the DMA transfer.
110 * @component: triggered component
111 * @substream: triggered substream
112 * @cmd: triggered command
113 *
114 * This function is called by ALSA to start, stop, pause, and resume the DMA
115 * transfer of data.
116 */
117static int psc_dma_trigger(struct snd_soc_component *component,
118			   struct snd_pcm_substream *substream, int cmd)
119{
120	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
121	struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
122	struct snd_pcm_runtime *runtime = substream->runtime;
123	struct psc_dma_stream *s = to_psc_dma_stream(substream, psc_dma);
124	struct mpc52xx_psc __iomem *regs = psc_dma->psc_regs;
125	u16 imr;
126	unsigned long flags;
127	int i;
128
129	switch (cmd) {
130	case SNDRV_PCM_TRIGGER_START:
131		dev_dbg(psc_dma->dev, "START: stream=%i fbits=%u ps=%u #p=%u\n",
132			substream->pstr->stream, runtime->frame_bits,
133			(int)runtime->period_size, runtime->periods);
134		s->period_bytes = frames_to_bytes(runtime,
135						  runtime->period_size);
136		s->period_next = 0;
137		s->period_current = 0;
138		s->active = 1;
139		s->period_count = 0;
140		s->runtime = runtime;
141
142		/* Fill up the bestcomm bd queue and enable DMA.
143		 * This will begin filling the PSC's fifo.
144		 */
145		spin_lock_irqsave(&psc_dma->lock, flags);
146
147		if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
148			bcom_gen_bd_rx_reset(s->bcom_task);
149		else
150			bcom_gen_bd_tx_reset(s->bcom_task);
151
152		for (i = 0; i < runtime->periods; i++)
153			if (!bcom_queue_full(s->bcom_task))
154				psc_dma_bcom_enqueue_next_buffer(s);
155
156		bcom_enable(s->bcom_task);
157		spin_unlock_irqrestore(&psc_dma->lock, flags);
158
159		out_8(&regs->command, MPC52xx_PSC_RST_ERR_STAT);
160
161		break;
162
163	case SNDRV_PCM_TRIGGER_STOP:
164		dev_dbg(psc_dma->dev, "STOP: stream=%i periods_count=%i\n",
165			substream->pstr->stream, s->period_count);
166		s->active = 0;
167
168		spin_lock_irqsave(&psc_dma->lock, flags);
169		bcom_disable(s->bcom_task);
170		if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
171			bcom_gen_bd_rx_reset(s->bcom_task);
172		else
173			bcom_gen_bd_tx_reset(s->bcom_task);
174		spin_unlock_irqrestore(&psc_dma->lock, flags);
175
176		break;
177
178	default:
179		dev_dbg(psc_dma->dev, "unhandled trigger: stream=%i cmd=%i\n",
180			substream->pstr->stream, cmd);
181		return -EINVAL;
182	}
183
184	/* Update interrupt enable settings */
185	imr = 0;
186	if (psc_dma->playback.active)
187		imr |= MPC52xx_PSC_IMR_TXEMP;
188	if (psc_dma->capture.active)
189		imr |= MPC52xx_PSC_IMR_ORERR;
190	out_be16(&regs->isr_imr.imr, psc_dma->imr | imr);
191
192	return 0;
193}
194
195
196/* ---------------------------------------------------------------------
197 * The PSC DMA 'ASoC platform' driver
198 *
199 * Can be referenced by an 'ASoC machine' driver
200 * This driver only deals with the audio bus; it doesn't have any
201 * interaction with the attached codec
202 */
203
204static const struct snd_pcm_hardware psc_dma_hardware = {
205	.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
206		SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
207		SNDRV_PCM_INFO_BATCH,
208	.formats = SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_BE |
209		SNDRV_PCM_FMTBIT_S24_BE | SNDRV_PCM_FMTBIT_S32_BE,
210	.period_bytes_max	= 1024 * 1024,
211	.period_bytes_min	= 32,
212	.periods_min		= 2,
213	.periods_max		= 256,
214	.buffer_bytes_max	= 2 * 1024 * 1024,
215	.fifo_size		= 512,
216};
217
218static int psc_dma_open(struct snd_soc_component *component,
219			struct snd_pcm_substream *substream)
220{
221	struct snd_pcm_runtime *runtime = substream->runtime;
222	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
223	struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
224	struct psc_dma_stream *s;
225	int rc;
226
227	dev_dbg(psc_dma->dev, "psc_dma_open(substream=%p)\n", substream);
228
229	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
230		s = &psc_dma->capture;
231	else
232		s = &psc_dma->playback;
233
234	snd_soc_set_runtime_hwparams(substream, &psc_dma_hardware);
235
236	rc = snd_pcm_hw_constraint_integer(runtime,
237		SNDRV_PCM_HW_PARAM_PERIODS);
238	if (rc < 0) {
239		dev_err(substream->pcm->card->dev, "invalid buffer size\n");
240		return rc;
241	}
242
243	s->stream = substream;
244	return 0;
245}
246
247static int psc_dma_close(struct snd_soc_component *component,
248			 struct snd_pcm_substream *substream)
249{
250	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
251	struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
252	struct psc_dma_stream *s;
253
254	dev_dbg(psc_dma->dev, "psc_dma_close(substream=%p)\n", substream);
255
256	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
257		s = &psc_dma->capture;
258	else
259		s = &psc_dma->playback;
260
261	if (!psc_dma->playback.active &&
262	    !psc_dma->capture.active) {
263
264		/* Disable all interrupts and reset the PSC */
265		out_be16(&psc_dma->psc_regs->isr_imr.imr, psc_dma->imr);
266		out_8(&psc_dma->psc_regs->command, 4 << 4); /* reset error */
267	}
268	s->stream = NULL;
269	return 0;
270}
271
272static snd_pcm_uframes_t
273psc_dma_pointer(struct snd_soc_component *component,
274		struct snd_pcm_substream *substream)
275{
276	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
277	struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
278	struct psc_dma_stream *s;
279	dma_addr_t count;
280
281	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
282		s = &psc_dma->capture;
283	else
284		s = &psc_dma->playback;
285
286	count = s->period_current * s->period_bytes;
287
288	return bytes_to_frames(substream->runtime, count);
289}
290
291static int psc_dma_hw_params(struct snd_soc_component *component,
292			     struct snd_pcm_substream *substream,
293			     struct snd_pcm_hw_params *params)
294{
295	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
296
297	return 0;
298}
299
300static int psc_dma_new(struct snd_soc_component *component,
301		       struct snd_soc_pcm_runtime *rtd)
302{
303	struct snd_card *card = rtd->card->snd_card;
304	struct snd_soc_dai *dai = asoc_rtd_to_cpu(rtd, 0);
305	struct snd_pcm *pcm = rtd->pcm;
306	size_t size = psc_dma_hardware.buffer_bytes_max;
307	int rc;
308
309	dev_dbg(component->dev, "psc_dma_new(card=%p, dai=%p, pcm=%p)\n",
310		card, dai, pcm);
311
312	rc = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
313	if (rc)
314		return rc;
315
316	if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
317		rc = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, pcm->card->dev,
318				size, &pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream->dma_buffer);
319		if (rc)
320			goto playback_alloc_err;
321	}
322
323	if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
324		rc = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, pcm->card->dev,
325				size, &pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream->dma_buffer);
326		if (rc)
327			goto capture_alloc_err;
328	}
329
330	return 0;
331
332 capture_alloc_err:
333	if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
334		snd_dma_free_pages(&pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream->dma_buffer);
335
336 playback_alloc_err:
337	dev_err(card->dev, "Cannot allocate buffer(s)\n");
338
339	return -ENOMEM;
340}
341
342static void psc_dma_free(struct snd_soc_component *component,
343			 struct snd_pcm *pcm)
344{
345	struct snd_pcm_substream *substream;
346	int stream;
347
348	dev_dbg(component->dev, "psc_dma_free(pcm=%p)\n", pcm);
349
350	for (stream = 0; stream < 2; stream++) {
351		substream = pcm->streams[stream].substream;
352		if (substream) {
353			snd_dma_free_pages(&substream->dma_buffer);
354			substream->dma_buffer.area = NULL;
355			substream->dma_buffer.addr = 0;
356		}
357	}
358}
359
360static const struct snd_soc_component_driver mpc5200_audio_dma_component = {
361	.name		= DRV_NAME,
362	.open		= psc_dma_open,
363	.close		= psc_dma_close,
364	.hw_free	= psc_dma_hw_free,
365	.pointer	= psc_dma_pointer,
366	.trigger	= psc_dma_trigger,
367	.hw_params	= psc_dma_hw_params,
368	.pcm_construct	= psc_dma_new,
369	.pcm_destruct	= psc_dma_free,
370};
371
372int mpc5200_audio_dma_create(struct platform_device *op)
373{
374	phys_addr_t fifo;
375	struct psc_dma *psc_dma;
376	struct resource res;
377	int size, irq, rc;
378	const __be32 *prop;
379	void __iomem *regs;
380	int ret;
381
382	/* Fetch the registers and IRQ of the PSC */
383	irq = irq_of_parse_and_map(op->dev.of_node, 0);
384	if (of_address_to_resource(op->dev.of_node, 0, &res)) {
385		dev_err(&op->dev, "Missing reg property\n");
386		return -ENODEV;
387	}
388	regs = ioremap(res.start, resource_size(&res));
389	if (!regs) {
390		dev_err(&op->dev, "Could not map registers\n");
391		return -ENODEV;
392	}
393
394	/* Allocate and initialize the driver private data */
395	psc_dma = kzalloc(sizeof *psc_dma, GFP_KERNEL);
396	if (!psc_dma) {
397		ret = -ENOMEM;
398		goto out_unmap;
399	}
400
401	/* Get the PSC ID */
402	prop = of_get_property(op->dev.of_node, "cell-index", &size);
403	if (!prop || size < sizeof *prop) {
404		ret = -ENODEV;
405		goto out_free;
406	}
407
408	spin_lock_init(&psc_dma->lock);
409	mutex_init(&psc_dma->mutex);
410	psc_dma->id = be32_to_cpu(*prop);
411	psc_dma->irq = irq;
412	psc_dma->psc_regs = regs;
413	psc_dma->fifo_regs = regs + sizeof *psc_dma->psc_regs;
414	psc_dma->dev = &op->dev;
415	psc_dma->playback.psc_dma = psc_dma;
416	psc_dma->capture.psc_dma = psc_dma;
417	snprintf(psc_dma->name, sizeof psc_dma->name, "PSC%u", psc_dma->id);
418
419	/* Find the address of the fifo data registers and setup the
420	 * DMA tasks */
421	fifo = res.start + offsetof(struct mpc52xx_psc, buffer.buffer_32);
422	psc_dma->capture.bcom_task =
423		bcom_psc_gen_bd_rx_init(psc_dma->id, 10, fifo, 512);
424	psc_dma->playback.bcom_task =
425		bcom_psc_gen_bd_tx_init(psc_dma->id, 10, fifo);
426	if (!psc_dma->capture.bcom_task ||
427	    !psc_dma->playback.bcom_task) {
428		dev_err(&op->dev, "Could not allocate bestcomm tasks\n");
429		ret = -ENODEV;
430		goto out_free;
431	}
432
433	/* Disable all interrupts and reset the PSC */
434	out_be16(&psc_dma->psc_regs->isr_imr.imr, psc_dma->imr);
435	 /* reset receiver */
436	out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_RST_RX);
437	 /* reset transmitter */
438	out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_RST_TX);
439	 /* reset error */
440	out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_RST_ERR_STAT);
441	 /* reset mode */
442	out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_SEL_MODE_REG_1);
443
444	/* Set up mode register;
445	 * First write: RxRdy (FIFO Alarm) generates rx FIFO irq
446	 * Second write: register Normal mode for non loopback
447	 */
448	out_8(&psc_dma->psc_regs->mode, 0);
449	out_8(&psc_dma->psc_regs->mode, 0);
450
451	/* Set the TX and RX fifo alarm thresholds */
452	out_be16(&psc_dma->fifo_regs->rfalarm, 0x100);
453	out_8(&psc_dma->fifo_regs->rfcntl, 0x4);
454	out_be16(&psc_dma->fifo_regs->tfalarm, 0x100);
455	out_8(&psc_dma->fifo_regs->tfcntl, 0x7);
456
457	/* Lookup the IRQ numbers */
458	psc_dma->playback.irq =
459		bcom_get_task_irq(psc_dma->playback.bcom_task);
460	psc_dma->capture.irq =
461		bcom_get_task_irq(psc_dma->capture.bcom_task);
462
463	rc = request_irq(psc_dma->irq, &psc_dma_status_irq, IRQF_SHARED,
464			 "psc-dma-status", psc_dma);
465	rc |= request_irq(psc_dma->capture.irq, &psc_dma_bcom_irq, IRQF_SHARED,
466			  "psc-dma-capture", &psc_dma->capture);
467	rc |= request_irq(psc_dma->playback.irq, &psc_dma_bcom_irq, IRQF_SHARED,
468			  "psc-dma-playback", &psc_dma->playback);
469	if (rc) {
470		ret = -ENODEV;
471		goto out_irq;
472	}
473
474	/* Save what we've done so it can be found again later */
475	dev_set_drvdata(&op->dev, psc_dma);
476
477	/* Tell the ASoC OF helpers about it */
478	return devm_snd_soc_register_component(&op->dev,
479					&mpc5200_audio_dma_component, NULL, 0);
480out_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);
484out_free:
485	kfree(psc_dma);
486out_unmap:
487	iounmap(regs);
488	return ret;
489}
490EXPORT_SYMBOL_GPL(mpc5200_audio_dma_create);
491
492int 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	bcom_gen_bd_rx_release(psc_dma->capture.bcom_task);
499	bcom_gen_bd_tx_release(psc_dma->playback.bcom_task);
500
501	/* Release irqs */
502	free_irq(psc_dma->irq, psc_dma);
503	free_irq(psc_dma->capture.irq, &psc_dma->capture);
504	free_irq(psc_dma->playback.irq, &psc_dma->playback);
505
506	iounmap(psc_dma->psc_regs);
507	kfree(psc_dma);
508	dev_set_drvdata(&op->dev, NULL);
509
510	return 0;
511}
512EXPORT_SYMBOL_GPL(mpc5200_audio_dma_destroy);
513
514MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
515MODULE_DESCRIPTION("Freescale MPC5200 PSC in DMA mode ASoC Driver");
516MODULE_LICENSE("GPL");
517