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  */
psc_dma_status_irq(int irq,void * _psc_dma)30 static 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  */
psc_dma_bcom_enqueue_next_buffer(struct psc_dma_stream * s)61 static 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 */
psc_dma_bcom_irq(int irq,void * _psc_dma_stream)76 static 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 
101 /**
102  * psc_dma_trigger: start and stop the DMA transfer.
103  *
104  * This function is called by ALSA to start, stop, pause, and resume the DMA
105  * transfer of data.
106  */
psc_dma_trigger(struct snd_soc_component * component,struct snd_pcm_substream * substream,int cmd)107 static int psc_dma_trigger(struct snd_soc_component *component,
108 			   struct snd_pcm_substream *substream, int cmd)
109 {
110 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
111 	struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
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 	.period_bytes_max	= 1024 * 1024,
201 	.period_bytes_min	= 32,
202 	.periods_min		= 2,
203 	.periods_max		= 256,
204 	.buffer_bytes_max	= 2 * 1024 * 1024,
205 	.fifo_size		= 512,
206 };
207 
psc_dma_open(struct snd_soc_component * component,struct snd_pcm_substream * substream)208 static int psc_dma_open(struct snd_soc_component *component,
209 			struct snd_pcm_substream *substream)
210 {
211 	struct snd_pcm_runtime *runtime = substream->runtime;
212 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
213 	struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
214 	struct psc_dma_stream *s;
215 	int rc;
216 
217 	dev_dbg(psc_dma->dev, "psc_dma_open(substream=%p)\n", substream);
218 
219 	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
220 		s = &psc_dma->capture;
221 	else
222 		s = &psc_dma->playback;
223 
224 	snd_soc_set_runtime_hwparams(substream, &psc_dma_hardware);
225 
226 	rc = snd_pcm_hw_constraint_integer(runtime,
227 		SNDRV_PCM_HW_PARAM_PERIODS);
228 	if (rc < 0) {
229 		dev_err(substream->pcm->card->dev, "invalid buffer size\n");
230 		return rc;
231 	}
232 
233 	s->stream = substream;
234 	return 0;
235 }
236 
psc_dma_close(struct snd_soc_component * component,struct snd_pcm_substream * substream)237 static int psc_dma_close(struct snd_soc_component *component,
238 			 struct snd_pcm_substream *substream)
239 {
240 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
241 	struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
242 	struct psc_dma_stream *s;
243 
244 	dev_dbg(psc_dma->dev, "psc_dma_close(substream=%p)\n", substream);
245 
246 	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
247 		s = &psc_dma->capture;
248 	else
249 		s = &psc_dma->playback;
250 
251 	if (!psc_dma->playback.active &&
252 	    !psc_dma->capture.active) {
253 
254 		/* Disable all interrupts and reset the PSC */
255 		out_be16(&psc_dma->psc_regs->isr_imr.imr, psc_dma->imr);
256 		out_8(&psc_dma->psc_regs->command, 4 << 4); /* reset error */
257 	}
258 	s->stream = NULL;
259 	return 0;
260 }
261 
262 static snd_pcm_uframes_t
psc_dma_pointer(struct snd_soc_component * component,struct snd_pcm_substream * substream)263 psc_dma_pointer(struct snd_soc_component *component,
264 		struct snd_pcm_substream *substream)
265 {
266 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
267 	struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
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 
psc_dma_new(struct snd_soc_component * component,struct snd_soc_pcm_runtime * rtd)281 static int psc_dma_new(struct snd_soc_component *component,
282 		       struct snd_soc_pcm_runtime *rtd)
283 {
284 	struct snd_card *card = rtd->card->snd_card;
285 	struct snd_soc_dai *dai = asoc_rtd_to_cpu(rtd, 0);
286 	struct snd_pcm *pcm = rtd->pcm;
287 	size_t size = psc_dma_hardware.buffer_bytes_max;
288 	int rc;
289 
290 	dev_dbg(component->dev, "psc_dma_new(card=%p, dai=%p, pcm=%p)\n",
291 		card, dai, pcm);
292 
293 	rc = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
294 	if (rc)
295 		return rc;
296 
297 	return snd_pcm_set_fixed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV, card->dev,
298 					    size);
299 }
300 
301 static const struct snd_soc_component_driver mpc5200_audio_dma_component = {
302 	.name		= DRV_NAME,
303 	.open		= psc_dma_open,
304 	.close		= psc_dma_close,
305 	.pointer	= psc_dma_pointer,
306 	.trigger	= psc_dma_trigger,
307 	.pcm_construct	= psc_dma_new,
308 };
309 
mpc5200_audio_dma_create(struct platform_device * op)310 int mpc5200_audio_dma_create(struct platform_device *op)
311 {
312 	phys_addr_t fifo;
313 	struct psc_dma *psc_dma;
314 	struct resource res;
315 	int size, irq, rc;
316 	const __be32 *prop;
317 	void __iomem *regs;
318 	int ret;
319 
320 	/* Fetch the registers and IRQ of the PSC */
321 	irq = irq_of_parse_and_map(op->dev.of_node, 0);
322 	if (of_address_to_resource(op->dev.of_node, 0, &res)) {
323 		dev_err(&op->dev, "Missing reg property\n");
324 		return -ENODEV;
325 	}
326 	regs = ioremap(res.start, resource_size(&res));
327 	if (!regs) {
328 		dev_err(&op->dev, "Could not map registers\n");
329 		return -ENODEV;
330 	}
331 
332 	/* Allocate and initialize the driver private data */
333 	psc_dma = kzalloc(sizeof *psc_dma, GFP_KERNEL);
334 	if (!psc_dma) {
335 		ret = -ENOMEM;
336 		goto out_unmap;
337 	}
338 
339 	/* Get the PSC ID */
340 	prop = of_get_property(op->dev.of_node, "cell-index", &size);
341 	if (!prop || size < sizeof *prop) {
342 		ret = -ENODEV;
343 		goto out_free;
344 	}
345 
346 	spin_lock_init(&psc_dma->lock);
347 	mutex_init(&psc_dma->mutex);
348 	psc_dma->id = be32_to_cpu(*prop);
349 	psc_dma->irq = irq;
350 	psc_dma->psc_regs = regs;
351 	psc_dma->fifo_regs = regs + sizeof *psc_dma->psc_regs;
352 	psc_dma->dev = &op->dev;
353 	psc_dma->playback.psc_dma = psc_dma;
354 	psc_dma->capture.psc_dma = psc_dma;
355 	snprintf(psc_dma->name, sizeof(psc_dma->name), "PSC%d", psc_dma->id);
356 
357 	/* Find the address of the fifo data registers and setup the
358 	 * DMA tasks */
359 	fifo = res.start + offsetof(struct mpc52xx_psc, buffer.buffer_32);
360 	psc_dma->capture.bcom_task =
361 		bcom_psc_gen_bd_rx_init(psc_dma->id, 10, fifo, 512);
362 	psc_dma->playback.bcom_task =
363 		bcom_psc_gen_bd_tx_init(psc_dma->id, 10, fifo);
364 	if (!psc_dma->capture.bcom_task ||
365 	    !psc_dma->playback.bcom_task) {
366 		dev_err(&op->dev, "Could not allocate bestcomm tasks\n");
367 		ret = -ENODEV;
368 		goto out_free;
369 	}
370 
371 	/* Disable all interrupts and reset the PSC */
372 	out_be16(&psc_dma->psc_regs->isr_imr.imr, psc_dma->imr);
373 	 /* reset receiver */
374 	out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_RST_RX);
375 	 /* reset transmitter */
376 	out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_RST_TX);
377 	 /* reset error */
378 	out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_RST_ERR_STAT);
379 	 /* reset mode */
380 	out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_SEL_MODE_REG_1);
381 
382 	/* Set up mode register;
383 	 * First write: RxRdy (FIFO Alarm) generates rx FIFO irq
384 	 * Second write: register Normal mode for non loopback
385 	 */
386 	out_8(&psc_dma->psc_regs->mode, 0);
387 	out_8(&psc_dma->psc_regs->mode, 0);
388 
389 	/* Set the TX and RX fifo alarm thresholds */
390 	out_be16(&psc_dma->fifo_regs->rfalarm, 0x100);
391 	out_8(&psc_dma->fifo_regs->rfcntl, 0x4);
392 	out_be16(&psc_dma->fifo_regs->tfalarm, 0x100);
393 	out_8(&psc_dma->fifo_regs->tfcntl, 0x7);
394 
395 	/* Lookup the IRQ numbers */
396 	psc_dma->playback.irq =
397 		bcom_get_task_irq(psc_dma->playback.bcom_task);
398 	psc_dma->capture.irq =
399 		bcom_get_task_irq(psc_dma->capture.bcom_task);
400 
401 	rc = request_irq(psc_dma->irq, &psc_dma_status_irq, IRQF_SHARED,
402 			 "psc-dma-status", psc_dma);
403 	rc |= request_irq(psc_dma->capture.irq, &psc_dma_bcom_irq, IRQF_SHARED,
404 			  "psc-dma-capture", &psc_dma->capture);
405 	rc |= request_irq(psc_dma->playback.irq, &psc_dma_bcom_irq, IRQF_SHARED,
406 			  "psc-dma-playback", &psc_dma->playback);
407 	if (rc) {
408 		ret = -ENODEV;
409 		goto out_irq;
410 	}
411 
412 	/* Save what we've done so it can be found again later */
413 	dev_set_drvdata(&op->dev, psc_dma);
414 
415 	/* Tell the ASoC OF helpers about it */
416 	return devm_snd_soc_register_component(&op->dev,
417 					&mpc5200_audio_dma_component, NULL, 0);
418 out_irq:
419 	free_irq(psc_dma->irq, psc_dma);
420 	free_irq(psc_dma->capture.irq, &psc_dma->capture);
421 	free_irq(psc_dma->playback.irq, &psc_dma->playback);
422 out_free:
423 	kfree(psc_dma);
424 out_unmap:
425 	iounmap(regs);
426 	return ret;
427 }
428 EXPORT_SYMBOL_GPL(mpc5200_audio_dma_create);
429 
mpc5200_audio_dma_destroy(struct platform_device * op)430 int mpc5200_audio_dma_destroy(struct platform_device *op)
431 {
432 	struct psc_dma *psc_dma = dev_get_drvdata(&op->dev);
433 
434 	dev_dbg(&op->dev, "mpc5200_audio_dma_destroy()\n");
435 
436 	bcom_gen_bd_rx_release(psc_dma->capture.bcom_task);
437 	bcom_gen_bd_tx_release(psc_dma->playback.bcom_task);
438 
439 	/* Release irqs */
440 	free_irq(psc_dma->irq, psc_dma);
441 	free_irq(psc_dma->capture.irq, &psc_dma->capture);
442 	free_irq(psc_dma->playback.irq, &psc_dma->playback);
443 
444 	iounmap(psc_dma->psc_regs);
445 	kfree(psc_dma);
446 	dev_set_drvdata(&op->dev, NULL);
447 
448 	return 0;
449 }
450 EXPORT_SYMBOL_GPL(mpc5200_audio_dma_destroy);
451 
452 MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
453 MODULE_DESCRIPTION("Freescale MPC5200 PSC in DMA mode ASoC Driver");
454 MODULE_LICENSE("GPL");
455