xref: /openbmc/linux/sound/soc/fsl/mpc5200_psc_i2s.c (revision 9ac8d3fb)
1 /*
2  * Freescale MPC5200 PSC in I2S mode
3  * ALSA SoC Digital Audio Interface (DAI) driver
4  *
5  * Copyright (C) 2008 Secret Lab Technologies Ltd.
6  */
7 
8 #include <linux/init.h>
9 #include <linux/module.h>
10 #include <linux/interrupt.h>
11 #include <linux/device.h>
12 #include <linux/delay.h>
13 #include <linux/of_device.h>
14 #include <linux/of_platform.h>
15 #include <linux/dma-mapping.h>
16 
17 #include <sound/core.h>
18 #include <sound/pcm.h>
19 #include <sound/pcm_params.h>
20 #include <sound/initval.h>
21 #include <sound/soc.h>
22 #include <sound/soc-of-simple.h>
23 
24 #include <sysdev/bestcomm/bestcomm.h>
25 #include <sysdev/bestcomm/gen_bd.h>
26 #include <asm/mpc52xx_psc.h>
27 
28 MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
29 MODULE_DESCRIPTION("Freescale MPC5200 PSC in I2S mode ASoC Driver");
30 MODULE_LICENSE("GPL");
31 
32 /**
33  * PSC_I2S_RATES: sample rates supported by the I2S
34  *
35  * This driver currently only supports the PSC running in I2S slave mode,
36  * which means the codec determines the sample rate.  Therefore, we tell
37  * ALSA that we support all rates and let the codec driver decide what rates
38  * are really supported.
39  */
40 #define PSC_I2S_RATES (SNDRV_PCM_RATE_5512 | SNDRV_PCM_RATE_8000_192000 | \
41 			SNDRV_PCM_RATE_CONTINUOUS)
42 
43 /**
44  * PSC_I2S_FORMATS: audio formats supported by the PSC I2S mode
45  */
46 #define PSC_I2S_FORMATS (SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_BE | \
47 			 SNDRV_PCM_FMTBIT_S24_BE | SNDRV_PCM_FMTBIT_S24_BE | \
48 			 SNDRV_PCM_FMTBIT_S32_BE)
49 
50 /**
51  * psc_i2s_stream - Data specific to a single stream (playback or capture)
52  * @active:		flag indicating if the stream is active
53  * @psc_i2s:		pointer back to parent psc_i2s data structure
54  * @bcom_task:		bestcomm task structure
55  * @irq:		irq number for bestcomm task
56  * @period_start:	physical address of start of DMA region
57  * @period_end:		physical address of end of DMA region
58  * @period_next_pt:	physical address of next DMA buffer to enqueue
59  * @period_bytes:	size of DMA period in bytes
60  */
61 struct psc_i2s_stream {
62 	int active;
63 	struct psc_i2s *psc_i2s;
64 	struct bcom_task *bcom_task;
65 	int irq;
66 	struct snd_pcm_substream *stream;
67 	dma_addr_t period_start;
68 	dma_addr_t period_end;
69 	dma_addr_t period_next_pt;
70 	dma_addr_t period_current_pt;
71 	int period_bytes;
72 };
73 
74 /**
75  * psc_i2s - Private driver data
76  * @name: short name for this device ("PSC0", "PSC1", etc)
77  * @psc_regs: pointer to the PSC's registers
78  * @fifo_regs: pointer to the PSC's FIFO registers
79  * @irq: IRQ of this PSC
80  * @dev: struct device pointer
81  * @dai: the CPU DAI for this device
82  * @sicr: Base value used in serial interface control register; mode is ORed
83  *        with this value.
84  * @playback: Playback stream context data
85  * @capture: Capture stream context data
86  */
87 struct psc_i2s {
88 	char name[32];
89 	struct mpc52xx_psc __iomem *psc_regs;
90 	struct mpc52xx_psc_fifo __iomem *fifo_regs;
91 	unsigned int irq;
92 	struct device *dev;
93 	struct snd_soc_dai dai;
94 	spinlock_t lock;
95 	u32 sicr;
96 
97 	/* per-stream data */
98 	struct psc_i2s_stream playback;
99 	struct psc_i2s_stream capture;
100 
101 	/* Statistics */
102 	struct {
103 		int overrun_count;
104 		int underrun_count;
105 	} stats;
106 };
107 
108 /*
109  * Interrupt handlers
110  */
111 static irqreturn_t psc_i2s_status_irq(int irq, void *_psc_i2s)
112 {
113 	struct psc_i2s *psc_i2s = _psc_i2s;
114 	struct mpc52xx_psc __iomem *regs = psc_i2s->psc_regs;
115 	u16 isr;
116 
117 	isr = in_be16(&regs->mpc52xx_psc_isr);
118 
119 	/* Playback underrun error */
120 	if (psc_i2s->playback.active && (isr & MPC52xx_PSC_IMR_TXEMP))
121 		psc_i2s->stats.underrun_count++;
122 
123 	/* Capture overrun error */
124 	if (psc_i2s->capture.active && (isr & MPC52xx_PSC_IMR_ORERR))
125 		psc_i2s->stats.overrun_count++;
126 
127 	out_8(&regs->command, 4 << 4);	/* reset the error status */
128 
129 	return IRQ_HANDLED;
130 }
131 
132 /**
133  * psc_i2s_bcom_enqueue_next_buffer - Enqueue another audio buffer
134  * @s: pointer to stream private data structure
135  *
136  * Enqueues another audio period buffer into the bestcomm queue.
137  *
138  * Note: The routine must only be called when there is space available in
139  * the queue.  Otherwise the enqueue will fail and the audio ring buffer
140  * will get out of sync
141  */
142 static void psc_i2s_bcom_enqueue_next_buffer(struct psc_i2s_stream *s)
143 {
144 	struct bcom_bd *bd;
145 
146 	/* Prepare and enqueue the next buffer descriptor */
147 	bd = bcom_prepare_next_buffer(s->bcom_task);
148 	bd->status = s->period_bytes;
149 	bd->data[0] = s->period_next_pt;
150 	bcom_submit_next_buffer(s->bcom_task, NULL);
151 
152 	/* Update for next period */
153 	s->period_next_pt += s->period_bytes;
154 	if (s->period_next_pt >= s->period_end)
155 		s->period_next_pt = s->period_start;
156 }
157 
158 /* Bestcomm DMA irq handler */
159 static irqreturn_t psc_i2s_bcom_irq(int irq, void *_psc_i2s_stream)
160 {
161 	struct psc_i2s_stream *s = _psc_i2s_stream;
162 
163 	/* For each finished period, dequeue the completed period buffer
164 	 * and enqueue a new one in it's place. */
165 	while (bcom_buffer_done(s->bcom_task)) {
166 		bcom_retrieve_buffer(s->bcom_task, NULL, NULL);
167 		s->period_current_pt += s->period_bytes;
168 		if (s->period_current_pt >= s->period_end)
169 			s->period_current_pt = s->period_start;
170 		psc_i2s_bcom_enqueue_next_buffer(s);
171 		bcom_enable(s->bcom_task);
172 	}
173 
174 	/* If the stream is active, then also inform the PCM middle layer
175 	 * of the period finished event. */
176 	if (s->active)
177 		snd_pcm_period_elapsed(s->stream);
178 
179 	return IRQ_HANDLED;
180 }
181 
182 /**
183  * psc_i2s_startup: create a new substream
184  *
185  * This is the first function called when a stream is opened.
186  *
187  * If this is the first stream open, then grab the IRQ and program most of
188  * the PSC registers.
189  */
190 static int psc_i2s_startup(struct snd_pcm_substream *substream)
191 {
192 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
193 	struct psc_i2s *psc_i2s = rtd->dai->cpu_dai->private_data;
194 	int rc;
195 
196 	dev_dbg(psc_i2s->dev, "psc_i2s_startup(substream=%p)\n", substream);
197 
198 	if (!psc_i2s->playback.active &&
199 	    !psc_i2s->capture.active) {
200 		/* Setup the IRQs */
201 		rc = request_irq(psc_i2s->irq, &psc_i2s_status_irq, IRQF_SHARED,
202 				 "psc-i2s-status", psc_i2s);
203 		rc |= request_irq(psc_i2s->capture.irq,
204 				  &psc_i2s_bcom_irq, IRQF_SHARED,
205 				  "psc-i2s-capture", &psc_i2s->capture);
206 		rc |= request_irq(psc_i2s->playback.irq,
207 				  &psc_i2s_bcom_irq, IRQF_SHARED,
208 				  "psc-i2s-playback", &psc_i2s->playback);
209 		if (rc) {
210 			free_irq(psc_i2s->irq, psc_i2s);
211 			free_irq(psc_i2s->capture.irq,
212 				 &psc_i2s->capture);
213 			free_irq(psc_i2s->playback.irq,
214 				 &psc_i2s->playback);
215 			return -ENODEV;
216 		}
217 	}
218 
219 	return 0;
220 }
221 
222 static int psc_i2s_hw_params(struct snd_pcm_substream *substream,
223 				 struct snd_pcm_hw_params *params)
224 {
225 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
226 	struct psc_i2s *psc_i2s = rtd->dai->cpu_dai->private_data;
227 	u32 mode;
228 
229 	dev_dbg(psc_i2s->dev, "%s(substream=%p) p_size=%i p_bytes=%i"
230 		" periods=%i buffer_size=%i  buffer_bytes=%i\n",
231 		__func__, substream, params_period_size(params),
232 		params_period_bytes(params), params_periods(params),
233 		params_buffer_size(params), params_buffer_bytes(params));
234 
235 	switch (params_format(params)) {
236 	case SNDRV_PCM_FORMAT_S8:
237 		mode = MPC52xx_PSC_SICR_SIM_CODEC_8;
238 		break;
239 	case SNDRV_PCM_FORMAT_S16_BE:
240 		mode = MPC52xx_PSC_SICR_SIM_CODEC_16;
241 		break;
242 	case SNDRV_PCM_FORMAT_S24_BE:
243 		mode = MPC52xx_PSC_SICR_SIM_CODEC_24;
244 		break;
245 	case SNDRV_PCM_FORMAT_S32_BE:
246 		mode = MPC52xx_PSC_SICR_SIM_CODEC_32;
247 		break;
248 	default:
249 		dev_dbg(psc_i2s->dev, "invalid format\n");
250 		return -EINVAL;
251 	}
252 	out_be32(&psc_i2s->psc_regs->sicr, psc_i2s->sicr | mode);
253 
254 	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
255 
256 	return 0;
257 }
258 
259 static int psc_i2s_hw_free(struct snd_pcm_substream *substream)
260 {
261 	snd_pcm_set_runtime_buffer(substream, NULL);
262 	return 0;
263 }
264 
265 /**
266  * psc_i2s_trigger: start and stop the DMA transfer.
267  *
268  * This function is called by ALSA to start, stop, pause, and resume the DMA
269  * transfer of data.
270  */
271 static int psc_i2s_trigger(struct snd_pcm_substream *substream, int cmd)
272 {
273 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
274 	struct psc_i2s *psc_i2s = rtd->dai->cpu_dai->private_data;
275 	struct snd_pcm_runtime *runtime = substream->runtime;
276 	struct psc_i2s_stream *s;
277 	struct mpc52xx_psc __iomem *regs = psc_i2s->psc_regs;
278 	u16 imr;
279 	u8 psc_cmd;
280 	unsigned long flags;
281 
282 	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
283 		s = &psc_i2s->capture;
284 	else
285 		s = &psc_i2s->playback;
286 
287 	dev_dbg(psc_i2s->dev, "psc_i2s_trigger(substream=%p, cmd=%i)"
288 		" stream_id=%i\n",
289 		substream, cmd, substream->pstr->stream);
290 
291 	switch (cmd) {
292 	case SNDRV_PCM_TRIGGER_START:
293 		s->period_bytes = frames_to_bytes(runtime,
294 						  runtime->period_size);
295 		s->period_start = virt_to_phys(runtime->dma_area);
296 		s->period_end = s->period_start +
297 				(s->period_bytes * runtime->periods);
298 		s->period_next_pt = s->period_start;
299 		s->period_current_pt = s->period_start;
300 		s->active = 1;
301 
302 		/* First; reset everything */
303 		if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE) {
304 			out_8(&regs->command, MPC52xx_PSC_RST_RX);
305 			out_8(&regs->command, MPC52xx_PSC_RST_ERR_STAT);
306 		} else {
307 			out_8(&regs->command, MPC52xx_PSC_RST_TX);
308 			out_8(&regs->command, MPC52xx_PSC_RST_ERR_STAT);
309 		}
310 
311 		/* Next, fill up the bestcomm bd queue and enable DMA.
312 		 * This will begin filling the PSC's fifo. */
313 		if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
314 			bcom_gen_bd_rx_reset(s->bcom_task);
315 		else
316 			bcom_gen_bd_tx_reset(s->bcom_task);
317 		while (!bcom_queue_full(s->bcom_task))
318 			psc_i2s_bcom_enqueue_next_buffer(s);
319 		bcom_enable(s->bcom_task);
320 
321 		/* Due to errata in the i2s mode; need to line up enabling
322 		 * the transmitter with a transition on the frame sync
323 		 * line */
324 
325 		spin_lock_irqsave(&psc_i2s->lock, flags);
326 		/* first make sure it is low */
327 		while ((in_8(&regs->ipcr_acr.ipcr) & 0x80) != 0)
328 			;
329 		/* then wait for the transition to high */
330 		while ((in_8(&regs->ipcr_acr.ipcr) & 0x80) == 0)
331 			;
332 		/* Finally, enable the PSC.
333 		 * Receiver must always be enabled; even when we only want
334 		 * transmit.  (see 15.3.2.3 of MPC5200B User's Guide) */
335 		psc_cmd = MPC52xx_PSC_RX_ENABLE;
336 		if (substream->pstr->stream == SNDRV_PCM_STREAM_PLAYBACK)
337 			psc_cmd |= MPC52xx_PSC_TX_ENABLE;
338 		out_8(&regs->command, psc_cmd);
339 		spin_unlock_irqrestore(&psc_i2s->lock, flags);
340 
341 		break;
342 
343 	case SNDRV_PCM_TRIGGER_STOP:
344 		/* Turn off the PSC */
345 		s->active = 0;
346 		if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE) {
347 			if (!psc_i2s->playback.active) {
348 				out_8(&regs->command, 2 << 4);	/* reset rx */
349 				out_8(&regs->command, 3 << 4);	/* reset tx */
350 				out_8(&regs->command, 4 << 4);	/* reset err */
351 			}
352 		} else {
353 			out_8(&regs->command, 3 << 4);	/* reset tx */
354 			out_8(&regs->command, 4 << 4);	/* reset err */
355 			if (!psc_i2s->capture.active)
356 				out_8(&regs->command, 2 << 4);	/* reset rx */
357 		}
358 
359 		bcom_disable(s->bcom_task);
360 		while (!bcom_queue_empty(s->bcom_task))
361 			bcom_retrieve_buffer(s->bcom_task, NULL, NULL);
362 
363 		break;
364 
365 	default:
366 		dev_dbg(psc_i2s->dev, "invalid command\n");
367 		return -EINVAL;
368 	}
369 
370 	/* Update interrupt enable settings */
371 	imr = 0;
372 	if (psc_i2s->playback.active)
373 		imr |= MPC52xx_PSC_IMR_TXEMP;
374 	if (psc_i2s->capture.active)
375 		imr |= MPC52xx_PSC_IMR_ORERR;
376 	out_be16(&regs->isr_imr.imr, imr);
377 
378 	return 0;
379 }
380 
381 /**
382  * psc_i2s_shutdown: shutdown the data transfer on a stream
383  *
384  * Shutdown the PSC if there are no other substreams open.
385  */
386 static void psc_i2s_shutdown(struct snd_pcm_substream *substream)
387 {
388 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
389 	struct psc_i2s *psc_i2s = rtd->dai->cpu_dai->private_data;
390 
391 	dev_dbg(psc_i2s->dev, "psc_i2s_shutdown(substream=%p)\n", substream);
392 
393 	/*
394 	 * If this is the last active substream, disable the PSC and release
395 	 * the IRQ.
396 	 */
397 	if (!psc_i2s->playback.active &&
398 	    !psc_i2s->capture.active) {
399 
400 		/* Disable all interrupts and reset the PSC */
401 		out_be16(&psc_i2s->psc_regs->isr_imr.imr, 0);
402 		out_8(&psc_i2s->psc_regs->command, 3 << 4); /* reset tx */
403 		out_8(&psc_i2s->psc_regs->command, 2 << 4); /* reset rx */
404 		out_8(&psc_i2s->psc_regs->command, 1 << 4); /* reset mode */
405 		out_8(&psc_i2s->psc_regs->command, 4 << 4); /* reset error */
406 
407 		/* Release irqs */
408 		free_irq(psc_i2s->irq, psc_i2s);
409 		free_irq(psc_i2s->capture.irq, &psc_i2s->capture);
410 		free_irq(psc_i2s->playback.irq, &psc_i2s->playback);
411 	}
412 }
413 
414 /**
415  * psc_i2s_set_sysclk: set the clock frequency and direction
416  *
417  * This function is called by the machine driver to tell us what the clock
418  * frequency and direction are.
419  *
420  * Currently, we only support operating as a clock slave (SND_SOC_CLOCK_IN),
421  * and we don't care about the frequency.  Return an error if the direction
422  * is not SND_SOC_CLOCK_IN.
423  *
424  * @clk_id: reserved, should be zero
425  * @freq: the frequency of the given clock ID, currently ignored
426  * @dir: SND_SOC_CLOCK_IN (clock slave) or SND_SOC_CLOCK_OUT (clock master)
427  */
428 static int psc_i2s_set_sysclk(struct snd_soc_dai *cpu_dai,
429 			      int clk_id, unsigned int freq, int dir)
430 {
431 	struct psc_i2s *psc_i2s = cpu_dai->private_data;
432 	dev_dbg(psc_i2s->dev, "psc_i2s_set_sysclk(cpu_dai=%p, dir=%i)\n",
433 				cpu_dai, dir);
434 	return (dir == SND_SOC_CLOCK_IN) ? 0 : -EINVAL;
435 }
436 
437 /**
438  * psc_i2s_set_fmt: set the serial format.
439  *
440  * This function is called by the machine driver to tell us what serial
441  * format to use.
442  *
443  * This driver only supports I2S mode.  Return an error if the format is
444  * not SND_SOC_DAIFMT_I2S.
445  *
446  * @format: one of SND_SOC_DAIFMT_xxx
447  */
448 static int psc_i2s_set_fmt(struct snd_soc_dai *cpu_dai, unsigned int format)
449 {
450 	struct psc_i2s *psc_i2s = cpu_dai->private_data;
451 	dev_dbg(psc_i2s->dev, "psc_i2s_set_fmt(cpu_dai=%p, format=%i)\n",
452 				cpu_dai, format);
453 	return (format == SND_SOC_DAIFMT_I2S) ? 0 : -EINVAL;
454 }
455 
456 /* ---------------------------------------------------------------------
457  * ALSA SoC Bindings
458  *
459  * - Digital Audio Interface (DAI) template
460  * - create/destroy dai hooks
461  */
462 
463 /**
464  * psc_i2s_dai_template: template CPU Digital Audio Interface
465  */
466 static struct snd_soc_dai psc_i2s_dai_template = {
467 	.type = SND_SOC_DAI_I2S,
468 	.playback = {
469 		.channels_min = 2,
470 		.channels_max = 2,
471 		.rates = PSC_I2S_RATES,
472 		.formats = PSC_I2S_FORMATS,
473 	},
474 	.capture = {
475 		.channels_min = 2,
476 		.channels_max = 2,
477 		.rates = PSC_I2S_RATES,
478 		.formats = PSC_I2S_FORMATS,
479 	},
480 	.ops = {
481 		.startup = psc_i2s_startup,
482 		.hw_params = psc_i2s_hw_params,
483 		.hw_free = psc_i2s_hw_free,
484 		.shutdown = psc_i2s_shutdown,
485 		.trigger = psc_i2s_trigger,
486 	},
487 	.dai_ops = {
488 		.set_sysclk = psc_i2s_set_sysclk,
489 		.set_fmt = psc_i2s_set_fmt,
490 	},
491 };
492 
493 /* ---------------------------------------------------------------------
494  * The PSC I2S 'ASoC platform' driver
495  *
496  * Can be referenced by an 'ASoC machine' driver
497  * This driver only deals with the audio bus; it doesn't have any
498  * interaction with the attached codec
499  */
500 
501 static const struct snd_pcm_hardware psc_i2s_pcm_hardware = {
502 	.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
503 		SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER,
504 	.formats = SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_BE |
505 		   SNDRV_PCM_FMTBIT_S24_BE | SNDRV_PCM_FMTBIT_S32_BE,
506 	.rate_min = 8000,
507 	.rate_max = 48000,
508 	.channels_min = 2,
509 	.channels_max = 2,
510 	.period_bytes_max	= 1024 * 1024,
511 	.period_bytes_min	= 32,
512 	.periods_min		= 2,
513 	.periods_max		= 256,
514 	.buffer_bytes_max	= 2 * 1024 * 1024,
515 	.fifo_size		= 0,
516 };
517 
518 static int psc_i2s_pcm_open(struct snd_pcm_substream *substream)
519 {
520 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
521 	struct psc_i2s *psc_i2s = rtd->dai->cpu_dai->private_data;
522 	struct psc_i2s_stream *s;
523 
524 	dev_dbg(psc_i2s->dev, "psc_i2s_pcm_open(substream=%p)\n", substream);
525 
526 	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
527 		s = &psc_i2s->capture;
528 	else
529 		s = &psc_i2s->playback;
530 
531 	snd_soc_set_runtime_hwparams(substream, &psc_i2s_pcm_hardware);
532 
533 	s->stream = substream;
534 	return 0;
535 }
536 
537 static int psc_i2s_pcm_close(struct snd_pcm_substream *substream)
538 {
539 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
540 	struct psc_i2s *psc_i2s = rtd->dai->cpu_dai->private_data;
541 	struct psc_i2s_stream *s;
542 
543 	dev_dbg(psc_i2s->dev, "psc_i2s_pcm_close(substream=%p)\n", substream);
544 
545 	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
546 		s = &psc_i2s->capture;
547 	else
548 		s = &psc_i2s->playback;
549 
550 	s->stream = NULL;
551 	return 0;
552 }
553 
554 static snd_pcm_uframes_t
555 psc_i2s_pcm_pointer(struct snd_pcm_substream *substream)
556 {
557 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
558 	struct psc_i2s *psc_i2s = rtd->dai->cpu_dai->private_data;
559 	struct psc_i2s_stream *s;
560 	dma_addr_t count;
561 
562 	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
563 		s = &psc_i2s->capture;
564 	else
565 		s = &psc_i2s->playback;
566 
567 	count = s->period_current_pt - s->period_start;
568 
569 	return bytes_to_frames(substream->runtime, count);
570 }
571 
572 static struct snd_pcm_ops psc_i2s_pcm_ops = {
573 	.open		= psc_i2s_pcm_open,
574 	.close		= psc_i2s_pcm_close,
575 	.ioctl		= snd_pcm_lib_ioctl,
576 	.pointer	= psc_i2s_pcm_pointer,
577 };
578 
579 static u64 psc_i2s_pcm_dmamask = 0xffffffff;
580 static int psc_i2s_pcm_new(struct snd_card *card, struct snd_soc_dai *dai,
581 			   struct snd_pcm *pcm)
582 {
583 	struct snd_soc_pcm_runtime *rtd = pcm->private_data;
584 	size_t size = psc_i2s_pcm_hardware.buffer_bytes_max;
585 	int rc = 0;
586 
587 	dev_dbg(rtd->socdev->dev, "psc_i2s_pcm_new(card=%p, dai=%p, pcm=%p)\n",
588 		card, dai, pcm);
589 
590 	if (!card->dev->dma_mask)
591 		card->dev->dma_mask = &psc_i2s_pcm_dmamask;
592 	if (!card->dev->coherent_dma_mask)
593 		card->dev->coherent_dma_mask = 0xffffffff;
594 
595 	if (pcm->streams[0].substream) {
596 		rc = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, pcm->dev, size,
597 					&pcm->streams[0].substream->dma_buffer);
598 		if (rc)
599 			goto playback_alloc_err;
600 	}
601 
602 	if (pcm->streams[1].substream) {
603 		rc = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, pcm->dev, size,
604 					&pcm->streams[1].substream->dma_buffer);
605 		if (rc)
606 			goto capture_alloc_err;
607 	}
608 
609 	return 0;
610 
611  capture_alloc_err:
612 	if (pcm->streams[0].substream)
613 		snd_dma_free_pages(&pcm->streams[0].substream->dma_buffer);
614  playback_alloc_err:
615 	dev_err(card->dev, "Cannot allocate buffer(s)\n");
616 	return -ENOMEM;
617 }
618 
619 static void psc_i2s_pcm_free(struct snd_pcm *pcm)
620 {
621 	struct snd_soc_pcm_runtime *rtd = pcm->private_data;
622 	struct snd_pcm_substream *substream;
623 	int stream;
624 
625 	dev_dbg(rtd->socdev->dev, "psc_i2s_pcm_free(pcm=%p)\n", pcm);
626 
627 	for (stream = 0; stream < 2; stream++) {
628 		substream = pcm->streams[stream].substream;
629 		if (substream) {
630 			snd_dma_free_pages(&substream->dma_buffer);
631 			substream->dma_buffer.area = NULL;
632 			substream->dma_buffer.addr = 0;
633 		}
634 	}
635 }
636 
637 struct snd_soc_platform psc_i2s_pcm_soc_platform = {
638 	.name		= "mpc5200-psc-audio",
639 	.pcm_ops	= &psc_i2s_pcm_ops,
640 	.pcm_new	= &psc_i2s_pcm_new,
641 	.pcm_free	= &psc_i2s_pcm_free,
642 };
643 
644 /* ---------------------------------------------------------------------
645  * Sysfs attributes for debugging
646  */
647 
648 static ssize_t psc_i2s_status_show(struct device *dev,
649 			   struct device_attribute *attr, char *buf)
650 {
651 	struct psc_i2s *psc_i2s = dev_get_drvdata(dev);
652 
653 	return sprintf(buf, "status=%.4x sicr=%.8x rfnum=%i rfstat=0x%.4x "
654 			"tfnum=%i tfstat=0x%.4x\n",
655 			in_be16(&psc_i2s->psc_regs->sr_csr.status),
656 			in_be32(&psc_i2s->psc_regs->sicr),
657 			in_be16(&psc_i2s->fifo_regs->rfnum) & 0x1ff,
658 			in_be16(&psc_i2s->fifo_regs->rfstat),
659 			in_be16(&psc_i2s->fifo_regs->tfnum) & 0x1ff,
660 			in_be16(&psc_i2s->fifo_regs->tfstat));
661 }
662 
663 static int *psc_i2s_get_stat_attr(struct psc_i2s *psc_i2s, const char *name)
664 {
665 	if (strcmp(name, "playback_underrun") == 0)
666 		return &psc_i2s->stats.underrun_count;
667 	if (strcmp(name, "capture_overrun") == 0)
668 		return &psc_i2s->stats.overrun_count;
669 
670 	return NULL;
671 }
672 
673 static ssize_t psc_i2s_stat_show(struct device *dev,
674 				 struct device_attribute *attr, char *buf)
675 {
676 	struct psc_i2s *psc_i2s = dev_get_drvdata(dev);
677 	int *attrib;
678 
679 	attrib = psc_i2s_get_stat_attr(psc_i2s, attr->attr.name);
680 	if (!attrib)
681 		return 0;
682 
683 	return sprintf(buf, "%i\n", *attrib);
684 }
685 
686 static ssize_t psc_i2s_stat_store(struct device *dev,
687 				  struct device_attribute *attr,
688 				  const char *buf,
689 				  size_t count)
690 {
691 	struct psc_i2s *psc_i2s = dev_get_drvdata(dev);
692 	int *attrib;
693 
694 	attrib = psc_i2s_get_stat_attr(psc_i2s, attr->attr.name);
695 	if (!attrib)
696 		return 0;
697 
698 	*attrib = simple_strtoul(buf, NULL, 0);
699 	return count;
700 }
701 
702 static DEVICE_ATTR(status, 0644, psc_i2s_status_show, NULL);
703 static DEVICE_ATTR(playback_underrun, 0644, psc_i2s_stat_show,
704 			psc_i2s_stat_store);
705 static DEVICE_ATTR(capture_overrun, 0644, psc_i2s_stat_show,
706 			psc_i2s_stat_store);
707 
708 /* ---------------------------------------------------------------------
709  * OF platform bus binding code:
710  * - Probe/remove operations
711  * - OF device match table
712  */
713 static int __devinit psc_i2s_of_probe(struct of_device *op,
714 				      const struct of_device_id *match)
715 {
716 	phys_addr_t fifo;
717 	struct psc_i2s *psc_i2s;
718 	struct resource res;
719 	int size, psc_id, irq, rc;
720 	const __be32 *prop;
721 	void __iomem *regs;
722 
723 	dev_dbg(&op->dev, "probing psc i2s device\n");
724 
725 	/* Get the PSC ID */
726 	prop = of_get_property(op->node, "cell-index", &size);
727 	if (!prop || size < sizeof *prop)
728 		return -ENODEV;
729 	psc_id = be32_to_cpu(*prop);
730 
731 	/* Fetch the registers and IRQ of the PSC */
732 	irq = irq_of_parse_and_map(op->node, 0);
733 	if (of_address_to_resource(op->node, 0, &res)) {
734 		dev_err(&op->dev, "Missing reg property\n");
735 		return -ENODEV;
736 	}
737 	regs = ioremap(res.start, 1 + res.end - res.start);
738 	if (!regs) {
739 		dev_err(&op->dev, "Could not map registers\n");
740 		return -ENODEV;
741 	}
742 
743 	/* Allocate and initialize the driver private data */
744 	psc_i2s = kzalloc(sizeof *psc_i2s, GFP_KERNEL);
745 	if (!psc_i2s) {
746 		iounmap(regs);
747 		return -ENOMEM;
748 	}
749 	spin_lock_init(&psc_i2s->lock);
750 	psc_i2s->irq = irq;
751 	psc_i2s->psc_regs = regs;
752 	psc_i2s->fifo_regs = regs + sizeof *psc_i2s->psc_regs;
753 	psc_i2s->dev = &op->dev;
754 	psc_i2s->playback.psc_i2s = psc_i2s;
755 	psc_i2s->capture.psc_i2s = psc_i2s;
756 	snprintf(psc_i2s->name, sizeof psc_i2s->name, "PSC%u", psc_id+1);
757 
758 	/* Fill out the CPU DAI structure */
759 	memcpy(&psc_i2s->dai, &psc_i2s_dai_template, sizeof psc_i2s->dai);
760 	psc_i2s->dai.private_data = psc_i2s;
761 	psc_i2s->dai.name = psc_i2s->name;
762 	psc_i2s->dai.id = psc_id;
763 
764 	/* Find the address of the fifo data registers and setup the
765 	 * DMA tasks */
766 	fifo = res.start + offsetof(struct mpc52xx_psc, buffer.buffer_32);
767 	psc_i2s->capture.bcom_task =
768 		bcom_psc_gen_bd_rx_init(psc_id, 10, fifo, 512);
769 	psc_i2s->playback.bcom_task =
770 		bcom_psc_gen_bd_tx_init(psc_id, 10, fifo);
771 	if (!psc_i2s->capture.bcom_task ||
772 	    !psc_i2s->playback.bcom_task) {
773 		dev_err(&op->dev, "Could not allocate bestcomm tasks\n");
774 		iounmap(regs);
775 		kfree(psc_i2s);
776 		return -ENODEV;
777 	}
778 
779 	/* Disable all interrupts and reset the PSC */
780 	out_be16(&psc_i2s->psc_regs->isr_imr.imr, 0);
781 	out_8(&psc_i2s->psc_regs->command, 3 << 4); /* reset transmitter */
782 	out_8(&psc_i2s->psc_regs->command, 2 << 4); /* reset receiver */
783 	out_8(&psc_i2s->psc_regs->command, 1 << 4); /* reset mode */
784 	out_8(&psc_i2s->psc_regs->command, 4 << 4); /* reset error */
785 
786 	/* Configure the serial interface mode; defaulting to CODEC8 mode */
787 	psc_i2s->sicr = MPC52xx_PSC_SICR_DTS1 | MPC52xx_PSC_SICR_I2S |
788 			MPC52xx_PSC_SICR_CLKPOL;
789 	if (of_get_property(op->node, "fsl,cellslave", NULL))
790 		psc_i2s->sicr |= MPC52xx_PSC_SICR_CELLSLAVE |
791 				 MPC52xx_PSC_SICR_GENCLK;
792 	out_be32(&psc_i2s->psc_regs->sicr,
793 		 psc_i2s->sicr | MPC52xx_PSC_SICR_SIM_CODEC_8);
794 
795 	/* Check for the codec handle.  If it is not present then we
796 	 * are done */
797 	if (!of_get_property(op->node, "codec-handle", NULL))
798 		return 0;
799 
800 	/* Set up mode register;
801 	 * First write: RxRdy (FIFO Alarm) generates rx FIFO irq
802 	 * Second write: register Normal mode for non loopback
803 	 */
804 	out_8(&psc_i2s->psc_regs->mode, 0);
805 	out_8(&psc_i2s->psc_regs->mode, 0);
806 
807 	/* Set the TX and RX fifo alarm thresholds */
808 	out_be16(&psc_i2s->fifo_regs->rfalarm, 0x100);
809 	out_8(&psc_i2s->fifo_regs->rfcntl, 0x4);
810 	out_be16(&psc_i2s->fifo_regs->tfalarm, 0x100);
811 	out_8(&psc_i2s->fifo_regs->tfcntl, 0x7);
812 
813 	/* Lookup the IRQ numbers */
814 	psc_i2s->playback.irq =
815 		bcom_get_task_irq(psc_i2s->playback.bcom_task);
816 	psc_i2s->capture.irq =
817 		bcom_get_task_irq(psc_i2s->capture.bcom_task);
818 
819 	/* Save what we've done so it can be found again later */
820 	dev_set_drvdata(&op->dev, psc_i2s);
821 
822 	/* Register the SYSFS files */
823 	rc = device_create_file(psc_i2s->dev, &dev_attr_status);
824 	rc |= device_create_file(psc_i2s->dev, &dev_attr_capture_overrun);
825 	rc |= device_create_file(psc_i2s->dev, &dev_attr_playback_underrun);
826 	if (rc)
827 		dev_info(psc_i2s->dev, "error creating sysfs files\n");
828 
829 	/* Tell the ASoC OF helpers about it */
830 	of_snd_soc_register_platform(&psc_i2s_pcm_soc_platform, op->node,
831 				     &psc_i2s->dai);
832 
833 	return 0;
834 }
835 
836 static int __devexit psc_i2s_of_remove(struct of_device *op)
837 {
838 	struct psc_i2s *psc_i2s = dev_get_drvdata(&op->dev);
839 
840 	dev_dbg(&op->dev, "psc_i2s_remove()\n");
841 
842 	bcom_gen_bd_rx_release(psc_i2s->capture.bcom_task);
843 	bcom_gen_bd_tx_release(psc_i2s->playback.bcom_task);
844 
845 	iounmap(psc_i2s->psc_regs);
846 	iounmap(psc_i2s->fifo_regs);
847 	kfree(psc_i2s);
848 	dev_set_drvdata(&op->dev, NULL);
849 
850 	return 0;
851 }
852 
853 /* Match table for of_platform binding */
854 static struct of_device_id psc_i2s_match[] __devinitdata = {
855 	{ .compatible = "fsl,mpc5200-psc-i2s", },
856 	{}
857 };
858 MODULE_DEVICE_TABLE(of, psc_i2s_match);
859 
860 static struct of_platform_driver psc_i2s_driver = {
861 	.match_table = psc_i2s_match,
862 	.probe = psc_i2s_of_probe,
863 	.remove = __devexit_p(psc_i2s_of_remove),
864 	.driver = {
865 		.name = "mpc5200-psc-i2s",
866 		.owner = THIS_MODULE,
867 	},
868 };
869 
870 /* ---------------------------------------------------------------------
871  * Module setup and teardown; simply register the of_platform driver
872  * for the PSC in I2S mode.
873  */
874 static int __init psc_i2s_init(void)
875 {
876 	return of_register_platform_driver(&psc_i2s_driver);
877 }
878 module_init(psc_i2s_init);
879 
880 static void __exit psc_i2s_exit(void)
881 {
882 	of_unregister_platform_driver(&psc_i2s_driver);
883 }
884 module_exit(psc_i2s_exit);
885 
886 
887