1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * DesignWare HDMI audio driver
4  *
5  * Written and tested against the Designware HDMI Tx found in iMX6.
6  */
7 #include <linux/io.h>
8 #include <linux/interrupt.h>
9 #include <linux/module.h>
10 #include <linux/platform_device.h>
11 #include <drm/bridge/dw_hdmi.h>
12 #include <drm/drm_edid.h>
13 
14 #include <sound/asoundef.h>
15 #include <sound/core.h>
16 #include <sound/initval.h>
17 #include <sound/pcm.h>
18 #include <sound/pcm_drm_eld.h>
19 #include <sound/pcm_iec958.h>
20 
21 #include "dw-hdmi-audio.h"
22 
23 #define DRIVER_NAME "dw-hdmi-ahb-audio"
24 
25 /* Provide some bits rather than bit offsets */
26 enum {
27 	HDMI_AHB_DMA_CONF0_SW_FIFO_RST = BIT(7),
28 	HDMI_AHB_DMA_CONF0_EN_HLOCK = BIT(3),
29 	HDMI_AHB_DMA_START_START = BIT(0),
30 	HDMI_AHB_DMA_STOP_STOP = BIT(0),
31 	HDMI_IH_MUTE_AHBDMAAUD_STAT0_ERROR = BIT(5),
32 	HDMI_IH_MUTE_AHBDMAAUD_STAT0_LOST = BIT(4),
33 	HDMI_IH_MUTE_AHBDMAAUD_STAT0_RETRY = BIT(3),
34 	HDMI_IH_MUTE_AHBDMAAUD_STAT0_DONE = BIT(2),
35 	HDMI_IH_MUTE_AHBDMAAUD_STAT0_BUFFFULL = BIT(1),
36 	HDMI_IH_MUTE_AHBDMAAUD_STAT0_BUFFEMPTY = BIT(0),
37 	HDMI_IH_MUTE_AHBDMAAUD_STAT0_ALL =
38 		HDMI_IH_MUTE_AHBDMAAUD_STAT0_ERROR |
39 		HDMI_IH_MUTE_AHBDMAAUD_STAT0_LOST |
40 		HDMI_IH_MUTE_AHBDMAAUD_STAT0_RETRY |
41 		HDMI_IH_MUTE_AHBDMAAUD_STAT0_DONE |
42 		HDMI_IH_MUTE_AHBDMAAUD_STAT0_BUFFFULL |
43 		HDMI_IH_MUTE_AHBDMAAUD_STAT0_BUFFEMPTY,
44 	HDMI_IH_AHBDMAAUD_STAT0_ERROR = BIT(5),
45 	HDMI_IH_AHBDMAAUD_STAT0_LOST = BIT(4),
46 	HDMI_IH_AHBDMAAUD_STAT0_RETRY = BIT(3),
47 	HDMI_IH_AHBDMAAUD_STAT0_DONE = BIT(2),
48 	HDMI_IH_AHBDMAAUD_STAT0_BUFFFULL = BIT(1),
49 	HDMI_IH_AHBDMAAUD_STAT0_BUFFEMPTY = BIT(0),
50 	HDMI_IH_AHBDMAAUD_STAT0_ALL =
51 		HDMI_IH_AHBDMAAUD_STAT0_ERROR |
52 		HDMI_IH_AHBDMAAUD_STAT0_LOST |
53 		HDMI_IH_AHBDMAAUD_STAT0_RETRY |
54 		HDMI_IH_AHBDMAAUD_STAT0_DONE |
55 		HDMI_IH_AHBDMAAUD_STAT0_BUFFFULL |
56 		HDMI_IH_AHBDMAAUD_STAT0_BUFFEMPTY,
57 	HDMI_AHB_DMA_CONF0_INCR16 = 2 << 1,
58 	HDMI_AHB_DMA_CONF0_INCR8 = 1 << 1,
59 	HDMI_AHB_DMA_CONF0_INCR4 = 0,
60 	HDMI_AHB_DMA_CONF0_BURST_MODE = BIT(0),
61 	HDMI_AHB_DMA_MASK_DONE = BIT(7),
62 
63 	HDMI_REVISION_ID = 0x0001,
64 	HDMI_IH_AHBDMAAUD_STAT0 = 0x0109,
65 	HDMI_IH_MUTE_AHBDMAAUD_STAT0 = 0x0189,
66 	HDMI_AHB_DMA_CONF0 = 0x3600,
67 	HDMI_AHB_DMA_START = 0x3601,
68 	HDMI_AHB_DMA_STOP = 0x3602,
69 	HDMI_AHB_DMA_THRSLD = 0x3603,
70 	HDMI_AHB_DMA_STRADDR0 = 0x3604,
71 	HDMI_AHB_DMA_STPADDR0 = 0x3608,
72 	HDMI_AHB_DMA_MASK = 0x3614,
73 	HDMI_AHB_DMA_POL = 0x3615,
74 	HDMI_AHB_DMA_CONF1 = 0x3616,
75 	HDMI_AHB_DMA_BUFFPOL = 0x361a,
76 };
77 
78 struct dw_hdmi_channel_conf {
79 	u8 conf1;
80 	u8 ca;
81 };
82 
83 /*
84  * The default mapping of ALSA channels to HDMI channels and speaker
85  * allocation bits.  Note that we can't do channel remapping here -
86  * channels must be in the same order.
87  *
88  * Mappings for alsa-lib pcm/surround*.conf files:
89  *
90  *		Front	Sur4.0	Sur4.1	Sur5.0	Sur5.1	Sur7.1
91  * Channels	2	4	6	6	6	8
92  *
93  * Our mapping from ALSA channel to CEA686D speaker name and HDMI channel:
94  *
95  *				Number of ALSA channels
96  * ALSA Channel	2	3	4	5	6	7	8
97  * 0		FL:0	=	=	=	=	=	=
98  * 1		FR:1	=	=	=	=	=	=
99  * 2			FC:3	RL:4	LFE:2	=	=	=
100  * 3				RR:5	RL:4	FC:3	=	=
101  * 4					RR:5	RL:4	=	=
102  * 5						RR:5	=	=
103  * 6							RC:6	=
104  * 7							RLC/FRC	RLC/FRC
105  */
106 static struct dw_hdmi_channel_conf default_hdmi_channel_config[7] = {
107 	{ 0x03, 0x00 },	/* FL,FR */
108 	{ 0x0b, 0x02 },	/* FL,FR,FC */
109 	{ 0x33, 0x08 },	/* FL,FR,RL,RR */
110 	{ 0x37, 0x09 },	/* FL,FR,LFE,RL,RR */
111 	{ 0x3f, 0x0b },	/* FL,FR,LFE,FC,RL,RR */
112 	{ 0x7f, 0x0f },	/* FL,FR,LFE,FC,RL,RR,RC */
113 	{ 0xff, 0x13 },	/* FL,FR,LFE,FC,RL,RR,[FR]RC,[FR]LC */
114 };
115 
116 struct snd_dw_hdmi {
117 	struct snd_card *card;
118 	struct snd_pcm *pcm;
119 	spinlock_t lock;
120 	struct dw_hdmi_audio_data data;
121 	struct snd_pcm_substream *substream;
122 	void (*reformat)(struct snd_dw_hdmi *, size_t, size_t);
123 	void *buf_src;
124 	void *buf_dst;
125 	dma_addr_t buf_addr;
126 	unsigned buf_offset;
127 	unsigned buf_period;
128 	unsigned buf_size;
129 	unsigned channels;
130 	u8 revision;
131 	u8 iec_offset;
132 	u8 cs[192][8];
133 };
134 
135 static void dw_hdmi_writel(u32 val, void __iomem *ptr)
136 {
137 	writeb_relaxed(val, ptr);
138 	writeb_relaxed(val >> 8, ptr + 1);
139 	writeb_relaxed(val >> 16, ptr + 2);
140 	writeb_relaxed(val >> 24, ptr + 3);
141 }
142 
143 /*
144  * Convert to hardware format: The userspace buffer contains IEC958 samples,
145  * with the PCUV bits in bits 31..28 and audio samples in bits 27..4.  We
146  * need these to be in bits 27..24, with the IEC B bit in bit 28, and audio
147  * samples in 23..0.
148  *
149  * Default preamble in bits 3..0: 8 = block start, 4 = even 2 = odd
150  *
151  * Ideally, we could do with having the data properly formatted in userspace.
152  */
153 static void dw_hdmi_reformat_iec958(struct snd_dw_hdmi *dw,
154 	size_t offset, size_t bytes)
155 {
156 	u32 *src = dw->buf_src + offset;
157 	u32 *dst = dw->buf_dst + offset;
158 	u32 *end = dw->buf_src + offset + bytes;
159 
160 	do {
161 		u32 b, sample = *src++;
162 
163 		b = (sample & 8) << (28 - 3);
164 
165 		sample >>= 4;
166 
167 		*dst++ = sample | b;
168 	} while (src < end);
169 }
170 
171 static u32 parity(u32 sample)
172 {
173 	sample ^= sample >> 16;
174 	sample ^= sample >> 8;
175 	sample ^= sample >> 4;
176 	sample ^= sample >> 2;
177 	sample ^= sample >> 1;
178 	return (sample & 1) << 27;
179 }
180 
181 static void dw_hdmi_reformat_s24(struct snd_dw_hdmi *dw,
182 	size_t offset, size_t bytes)
183 {
184 	u32 *src = dw->buf_src + offset;
185 	u32 *dst = dw->buf_dst + offset;
186 	u32 *end = dw->buf_src + offset + bytes;
187 
188 	do {
189 		unsigned i;
190 		u8 *cs;
191 
192 		cs = dw->cs[dw->iec_offset++];
193 		if (dw->iec_offset >= 192)
194 			dw->iec_offset = 0;
195 
196 		i = dw->channels;
197 		do {
198 			u32 sample = *src++;
199 
200 			sample &= ~0xff000000;
201 			sample |= *cs++ << 24;
202 			sample |= parity(sample & ~0xf8000000);
203 
204 			*dst++ = sample;
205 		} while (--i);
206 	} while (src < end);
207 }
208 
209 static void dw_hdmi_create_cs(struct snd_dw_hdmi *dw,
210 	struct snd_pcm_runtime *runtime)
211 {
212 	u8 cs[4];
213 	unsigned ch, i, j;
214 
215 	snd_pcm_create_iec958_consumer(runtime, cs, sizeof(cs));
216 
217 	memset(dw->cs, 0, sizeof(dw->cs));
218 
219 	for (ch = 0; ch < 8; ch++) {
220 		cs[2] &= ~IEC958_AES2_CON_CHANNEL;
221 		cs[2] |= (ch + 1) << 4;
222 
223 		for (i = 0; i < ARRAY_SIZE(cs); i++) {
224 			unsigned c = cs[i];
225 
226 			for (j = 0; j < 8; j++, c >>= 1)
227 				dw->cs[i * 8 + j][ch] = (c & 1) << 2;
228 		}
229 	}
230 	dw->cs[0][0] |= BIT(4);
231 }
232 
233 static void dw_hdmi_start_dma(struct snd_dw_hdmi *dw)
234 {
235 	void __iomem *base = dw->data.base;
236 	unsigned offset = dw->buf_offset;
237 	unsigned period = dw->buf_period;
238 	u32 start, stop;
239 
240 	dw->reformat(dw, offset, period);
241 
242 	/* Clear all irqs before enabling irqs and starting DMA */
243 	writeb_relaxed(HDMI_IH_AHBDMAAUD_STAT0_ALL,
244 		       base + HDMI_IH_AHBDMAAUD_STAT0);
245 
246 	start = dw->buf_addr + offset;
247 	stop = start + period - 1;
248 
249 	/* Setup the hardware start/stop addresses */
250 	dw_hdmi_writel(start, base + HDMI_AHB_DMA_STRADDR0);
251 	dw_hdmi_writel(stop, base + HDMI_AHB_DMA_STPADDR0);
252 
253 	writeb_relaxed((u8)~HDMI_AHB_DMA_MASK_DONE, base + HDMI_AHB_DMA_MASK);
254 	writeb(HDMI_AHB_DMA_START_START, base + HDMI_AHB_DMA_START);
255 
256 	offset += period;
257 	if (offset >= dw->buf_size)
258 		offset = 0;
259 	dw->buf_offset = offset;
260 }
261 
262 static void dw_hdmi_stop_dma(struct snd_dw_hdmi *dw)
263 {
264 	/* Disable interrupts before disabling DMA */
265 	writeb_relaxed(~0, dw->data.base + HDMI_AHB_DMA_MASK);
266 	writeb_relaxed(HDMI_AHB_DMA_STOP_STOP, dw->data.base + HDMI_AHB_DMA_STOP);
267 }
268 
269 static irqreturn_t snd_dw_hdmi_irq(int irq, void *data)
270 {
271 	struct snd_dw_hdmi *dw = data;
272 	struct snd_pcm_substream *substream;
273 	unsigned stat;
274 
275 	stat = readb_relaxed(dw->data.base + HDMI_IH_AHBDMAAUD_STAT0);
276 	if (!stat)
277 		return IRQ_NONE;
278 
279 	writeb_relaxed(stat, dw->data.base + HDMI_IH_AHBDMAAUD_STAT0);
280 
281 	substream = dw->substream;
282 	if (stat & HDMI_IH_AHBDMAAUD_STAT0_DONE && substream) {
283 		snd_pcm_period_elapsed(substream);
284 
285 		spin_lock(&dw->lock);
286 		if (dw->substream)
287 			dw_hdmi_start_dma(dw);
288 		spin_unlock(&dw->lock);
289 	}
290 
291 	return IRQ_HANDLED;
292 }
293 
294 static const struct snd_pcm_hardware dw_hdmi_hw = {
295 	.info = SNDRV_PCM_INFO_INTERLEAVED |
296 		SNDRV_PCM_INFO_BLOCK_TRANSFER |
297 		SNDRV_PCM_INFO_MMAP |
298 		SNDRV_PCM_INFO_MMAP_VALID,
299 	.formats = SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_LE |
300 		   SNDRV_PCM_FMTBIT_S24_LE,
301 	.rates = SNDRV_PCM_RATE_32000 |
302 		 SNDRV_PCM_RATE_44100 |
303 		 SNDRV_PCM_RATE_48000 |
304 		 SNDRV_PCM_RATE_88200 |
305 		 SNDRV_PCM_RATE_96000 |
306 		 SNDRV_PCM_RATE_176400 |
307 		 SNDRV_PCM_RATE_192000,
308 	.channels_min = 2,
309 	.channels_max = 8,
310 	.buffer_bytes_max = 1024 * 1024,
311 	.period_bytes_min = 256,
312 	.period_bytes_max = 8192,	/* ERR004323: must limit to 8k */
313 	.periods_min = 2,
314 	.periods_max = 16,
315 	.fifo_size = 0,
316 };
317 
318 static int dw_hdmi_open(struct snd_pcm_substream *substream)
319 {
320 	struct snd_pcm_runtime *runtime = substream->runtime;
321 	struct snd_dw_hdmi *dw = substream->private_data;
322 	void __iomem *base = dw->data.base;
323 	u8 *eld;
324 	int ret;
325 
326 	runtime->hw = dw_hdmi_hw;
327 
328 	eld = dw->data.get_eld(dw->data.hdmi);
329 	if (eld) {
330 		ret = snd_pcm_hw_constraint_eld(runtime, eld);
331 		if (ret < 0)
332 			return ret;
333 	}
334 
335 	ret = snd_pcm_limit_hw_rates(runtime);
336 	if (ret < 0)
337 		return ret;
338 
339 	ret = snd_pcm_hw_constraint_integer(runtime,
340 					    SNDRV_PCM_HW_PARAM_PERIODS);
341 	if (ret < 0)
342 		return ret;
343 
344 	/* Limit the buffer size to the size of the preallocated buffer */
345 	ret = snd_pcm_hw_constraint_minmax(runtime,
346 					   SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
347 					   0, substream->dma_buffer.bytes);
348 	if (ret < 0)
349 		return ret;
350 
351 	/* Clear FIFO */
352 	writeb_relaxed(HDMI_AHB_DMA_CONF0_SW_FIFO_RST,
353 		       base + HDMI_AHB_DMA_CONF0);
354 
355 	/* Configure interrupt polarities */
356 	writeb_relaxed(~0, base + HDMI_AHB_DMA_POL);
357 	writeb_relaxed(~0, base + HDMI_AHB_DMA_BUFFPOL);
358 
359 	/* Keep interrupts masked, and clear any pending */
360 	writeb_relaxed(~0, base + HDMI_AHB_DMA_MASK);
361 	writeb_relaxed(~0, base + HDMI_IH_AHBDMAAUD_STAT0);
362 
363 	ret = request_irq(dw->data.irq, snd_dw_hdmi_irq, IRQF_SHARED,
364 			  "dw-hdmi-audio", dw);
365 	if (ret)
366 		return ret;
367 
368 	/* Un-mute done interrupt */
369 	writeb_relaxed(HDMI_IH_MUTE_AHBDMAAUD_STAT0_ALL &
370 		       ~HDMI_IH_MUTE_AHBDMAAUD_STAT0_DONE,
371 		       base + HDMI_IH_MUTE_AHBDMAAUD_STAT0);
372 
373 	return 0;
374 }
375 
376 static int dw_hdmi_close(struct snd_pcm_substream *substream)
377 {
378 	struct snd_dw_hdmi *dw = substream->private_data;
379 
380 	/* Mute all interrupts */
381 	writeb_relaxed(HDMI_IH_MUTE_AHBDMAAUD_STAT0_ALL,
382 		       dw->data.base + HDMI_IH_MUTE_AHBDMAAUD_STAT0);
383 
384 	free_irq(dw->data.irq, dw);
385 
386 	return 0;
387 }
388 
389 static int dw_hdmi_hw_free(struct snd_pcm_substream *substream)
390 {
391 	return snd_pcm_lib_free_vmalloc_buffer(substream);
392 }
393 
394 static int dw_hdmi_hw_params(struct snd_pcm_substream *substream,
395 	struct snd_pcm_hw_params *params)
396 {
397 	/* Allocate the PCM runtime buffer, which is exposed to userspace. */
398 	return snd_pcm_lib_alloc_vmalloc_buffer(substream,
399 						params_buffer_bytes(params));
400 }
401 
402 static int dw_hdmi_prepare(struct snd_pcm_substream *substream)
403 {
404 	struct snd_pcm_runtime *runtime = substream->runtime;
405 	struct snd_dw_hdmi *dw = substream->private_data;
406 	u8 threshold, conf0, conf1, ca;
407 
408 	/* Setup as per 3.0.5 FSL 4.1.0 BSP */
409 	switch (dw->revision) {
410 	case 0x0a:
411 		conf0 = HDMI_AHB_DMA_CONF0_BURST_MODE |
412 			HDMI_AHB_DMA_CONF0_INCR4;
413 		if (runtime->channels == 2)
414 			threshold = 126;
415 		else
416 			threshold = 124;
417 		break;
418 	case 0x1a:
419 		conf0 = HDMI_AHB_DMA_CONF0_BURST_MODE |
420 			HDMI_AHB_DMA_CONF0_INCR8;
421 		threshold = 128;
422 		break;
423 	default:
424 		/* NOTREACHED */
425 		return -EINVAL;
426 	}
427 
428 	dw_hdmi_set_sample_rate(dw->data.hdmi, runtime->rate);
429 
430 	/* Minimum number of bytes in the fifo. */
431 	runtime->hw.fifo_size = threshold * 32;
432 
433 	conf0 |= HDMI_AHB_DMA_CONF0_EN_HLOCK;
434 	conf1 = default_hdmi_channel_config[runtime->channels - 2].conf1;
435 	ca = default_hdmi_channel_config[runtime->channels - 2].ca;
436 
437 	writeb_relaxed(threshold, dw->data.base + HDMI_AHB_DMA_THRSLD);
438 	writeb_relaxed(conf0, dw->data.base + HDMI_AHB_DMA_CONF0);
439 	writeb_relaxed(conf1, dw->data.base + HDMI_AHB_DMA_CONF1);
440 
441 	dw_hdmi_set_channel_count(dw->data.hdmi, runtime->channels);
442 	dw_hdmi_set_channel_allocation(dw->data.hdmi, ca);
443 
444 	switch (runtime->format) {
445 	case SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE:
446 		dw->reformat = dw_hdmi_reformat_iec958;
447 		break;
448 	case SNDRV_PCM_FORMAT_S24_LE:
449 		dw_hdmi_create_cs(dw, runtime);
450 		dw->reformat = dw_hdmi_reformat_s24;
451 		break;
452 	}
453 	dw->iec_offset = 0;
454 	dw->channels = runtime->channels;
455 	dw->buf_src  = runtime->dma_area;
456 	dw->buf_dst  = substream->dma_buffer.area;
457 	dw->buf_addr = substream->dma_buffer.addr;
458 	dw->buf_period = snd_pcm_lib_period_bytes(substream);
459 	dw->buf_size = snd_pcm_lib_buffer_bytes(substream);
460 
461 	return 0;
462 }
463 
464 static int dw_hdmi_trigger(struct snd_pcm_substream *substream, int cmd)
465 {
466 	struct snd_dw_hdmi *dw = substream->private_data;
467 	unsigned long flags;
468 	int ret = 0;
469 
470 	switch (cmd) {
471 	case SNDRV_PCM_TRIGGER_START:
472 		spin_lock_irqsave(&dw->lock, flags);
473 		dw->buf_offset = 0;
474 		dw->substream = substream;
475 		dw_hdmi_start_dma(dw);
476 		dw_hdmi_audio_enable(dw->data.hdmi);
477 		spin_unlock_irqrestore(&dw->lock, flags);
478 		substream->runtime->delay = substream->runtime->period_size;
479 		break;
480 
481 	case SNDRV_PCM_TRIGGER_STOP:
482 		spin_lock_irqsave(&dw->lock, flags);
483 		dw->substream = NULL;
484 		dw_hdmi_stop_dma(dw);
485 		dw_hdmi_audio_disable(dw->data.hdmi);
486 		spin_unlock_irqrestore(&dw->lock, flags);
487 		break;
488 
489 	default:
490 		ret = -EINVAL;
491 		break;
492 	}
493 
494 	return ret;
495 }
496 
497 static snd_pcm_uframes_t dw_hdmi_pointer(struct snd_pcm_substream *substream)
498 {
499 	struct snd_pcm_runtime *runtime = substream->runtime;
500 	struct snd_dw_hdmi *dw = substream->private_data;
501 
502 	/*
503 	 * We are unable to report the exact hardware position as
504 	 * reading the 32-bit DMA position using 8-bit reads is racy.
505 	 */
506 	return bytes_to_frames(runtime, dw->buf_offset);
507 }
508 
509 static const struct snd_pcm_ops snd_dw_hdmi_ops = {
510 	.open = dw_hdmi_open,
511 	.close = dw_hdmi_close,
512 	.ioctl = snd_pcm_lib_ioctl,
513 	.hw_params = dw_hdmi_hw_params,
514 	.hw_free = dw_hdmi_hw_free,
515 	.prepare = dw_hdmi_prepare,
516 	.trigger = dw_hdmi_trigger,
517 	.pointer = dw_hdmi_pointer,
518 	.page = snd_pcm_lib_get_vmalloc_page,
519 };
520 
521 static int snd_dw_hdmi_probe(struct platform_device *pdev)
522 {
523 	const struct dw_hdmi_audio_data *data = pdev->dev.platform_data;
524 	struct device *dev = pdev->dev.parent;
525 	struct snd_dw_hdmi *dw;
526 	struct snd_card *card;
527 	struct snd_pcm *pcm;
528 	unsigned revision;
529 	int ret;
530 
531 	writeb_relaxed(HDMI_IH_MUTE_AHBDMAAUD_STAT0_ALL,
532 		       data->base + HDMI_IH_MUTE_AHBDMAAUD_STAT0);
533 	revision = readb_relaxed(data->base + HDMI_REVISION_ID);
534 	if (revision != 0x0a && revision != 0x1a) {
535 		dev_err(dev, "dw-hdmi-audio: unknown revision 0x%02x\n",
536 			revision);
537 		return -ENXIO;
538 	}
539 
540 	ret = snd_card_new(dev, SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1,
541 			      THIS_MODULE, sizeof(struct snd_dw_hdmi), &card);
542 	if (ret < 0)
543 		return ret;
544 
545 	strscpy(card->driver, DRIVER_NAME, sizeof(card->driver));
546 	strscpy(card->shortname, "DW-HDMI", sizeof(card->shortname));
547 	snprintf(card->longname, sizeof(card->longname),
548 		 "%s rev 0x%02x, irq %d", card->shortname, revision,
549 		 data->irq);
550 
551 	dw = card->private_data;
552 	dw->card = card;
553 	dw->data = *data;
554 	dw->revision = revision;
555 
556 	spin_lock_init(&dw->lock);
557 
558 	ret = snd_pcm_new(card, "DW HDMI", 0, 1, 0, &pcm);
559 	if (ret < 0)
560 		goto err;
561 
562 	dw->pcm = pcm;
563 	pcm->private_data = dw;
564 	strscpy(pcm->name, DRIVER_NAME, sizeof(pcm->name));
565 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_dw_hdmi_ops);
566 
567 	/*
568 	 * To support 8-channel 96kHz audio reliably, we need 512k
569 	 * to satisfy alsa with our restricted period (ERR004323).
570 	 */
571 	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
572 			dev, 128 * 1024, 1024 * 1024);
573 
574 	ret = snd_card_register(card);
575 	if (ret < 0)
576 		goto err;
577 
578 	platform_set_drvdata(pdev, dw);
579 
580 	return 0;
581 
582 err:
583 	snd_card_free(card);
584 	return ret;
585 }
586 
587 static int snd_dw_hdmi_remove(struct platform_device *pdev)
588 {
589 	struct snd_dw_hdmi *dw = platform_get_drvdata(pdev);
590 
591 	snd_card_free(dw->card);
592 
593 	return 0;
594 }
595 
596 #if defined(CONFIG_PM_SLEEP) && defined(IS_NOT_BROKEN)
597 /*
598  * This code is fine, but requires implementation in the dw_hdmi_trigger()
599  * method which is currently missing as I have no way to test this.
600  */
601 static int snd_dw_hdmi_suspend(struct device *dev)
602 {
603 	struct snd_dw_hdmi *dw = dev_get_drvdata(dev);
604 
605 	snd_power_change_state(dw->card, SNDRV_CTL_POWER_D3cold);
606 
607 	return 0;
608 }
609 
610 static int snd_dw_hdmi_resume(struct device *dev)
611 {
612 	struct snd_dw_hdmi *dw = dev_get_drvdata(dev);
613 
614 	snd_power_change_state(dw->card, SNDRV_CTL_POWER_D0);
615 
616 	return 0;
617 }
618 
619 static SIMPLE_DEV_PM_OPS(snd_dw_hdmi_pm, snd_dw_hdmi_suspend,
620 			 snd_dw_hdmi_resume);
621 #define PM_OPS &snd_dw_hdmi_pm
622 #else
623 #define PM_OPS NULL
624 #endif
625 
626 static struct platform_driver snd_dw_hdmi_driver = {
627 	.probe	= snd_dw_hdmi_probe,
628 	.remove	= snd_dw_hdmi_remove,
629 	.driver	= {
630 		.name = DRIVER_NAME,
631 		.pm = PM_OPS,
632 	},
633 };
634 
635 module_platform_driver(snd_dw_hdmi_driver);
636 
637 MODULE_AUTHOR("Russell King <rmk+kernel@armlinux.org.uk>");
638 MODULE_DESCRIPTION("Synopsis Designware HDMI AHB ALSA interface");
639 MODULE_LICENSE("GPL v2");
640 MODULE_ALIAS("platform:" DRIVER_NAME);
641