1 /*
2  * DesignWare HDMI audio driver
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  *
8  * Written and tested against the Designware HDMI Tx found in iMX6.
9  */
10 #include <linux/io.h>
11 #include <linux/interrupt.h>
12 #include <linux/module.h>
13 #include <linux/platform_device.h>
14 #include <drm/bridge/dw_hdmi.h>
15 #include <drm/drm_edid.h>
16 
17 #include <sound/asoundef.h>
18 #include <sound/core.h>
19 #include <sound/initval.h>
20 #include <sound/pcm.h>
21 #include <sound/pcm_drm_eld.h>
22 #include <sound/pcm_iec958.h>
23 
24 #include "dw-hdmi-audio.h"
25 
26 #define DRIVER_NAME "dw-hdmi-ahb-audio"
27 
28 /* Provide some bits rather than bit offsets */
29 enum {
30 	HDMI_AHB_DMA_CONF0_SW_FIFO_RST = BIT(7),
31 	HDMI_AHB_DMA_CONF0_EN_HLOCK = BIT(3),
32 	HDMI_AHB_DMA_START_START = BIT(0),
33 	HDMI_AHB_DMA_STOP_STOP = BIT(0),
34 	HDMI_IH_MUTE_AHBDMAAUD_STAT0_ERROR = BIT(5),
35 	HDMI_IH_MUTE_AHBDMAAUD_STAT0_LOST = BIT(4),
36 	HDMI_IH_MUTE_AHBDMAAUD_STAT0_RETRY = BIT(3),
37 	HDMI_IH_MUTE_AHBDMAAUD_STAT0_DONE = BIT(2),
38 	HDMI_IH_MUTE_AHBDMAAUD_STAT0_BUFFFULL = BIT(1),
39 	HDMI_IH_MUTE_AHBDMAAUD_STAT0_BUFFEMPTY = BIT(0),
40 	HDMI_IH_MUTE_AHBDMAAUD_STAT0_ALL =
41 		HDMI_IH_MUTE_AHBDMAAUD_STAT0_ERROR |
42 		HDMI_IH_MUTE_AHBDMAAUD_STAT0_LOST |
43 		HDMI_IH_MUTE_AHBDMAAUD_STAT0_RETRY |
44 		HDMI_IH_MUTE_AHBDMAAUD_STAT0_DONE |
45 		HDMI_IH_MUTE_AHBDMAAUD_STAT0_BUFFFULL |
46 		HDMI_IH_MUTE_AHBDMAAUD_STAT0_BUFFEMPTY,
47 	HDMI_IH_AHBDMAAUD_STAT0_ERROR = BIT(5),
48 	HDMI_IH_AHBDMAAUD_STAT0_LOST = BIT(4),
49 	HDMI_IH_AHBDMAAUD_STAT0_RETRY = BIT(3),
50 	HDMI_IH_AHBDMAAUD_STAT0_DONE = BIT(2),
51 	HDMI_IH_AHBDMAAUD_STAT0_BUFFFULL = BIT(1),
52 	HDMI_IH_AHBDMAAUD_STAT0_BUFFEMPTY = BIT(0),
53 	HDMI_IH_AHBDMAAUD_STAT0_ALL =
54 		HDMI_IH_AHBDMAAUD_STAT0_ERROR |
55 		HDMI_IH_AHBDMAAUD_STAT0_LOST |
56 		HDMI_IH_AHBDMAAUD_STAT0_RETRY |
57 		HDMI_IH_AHBDMAAUD_STAT0_DONE |
58 		HDMI_IH_AHBDMAAUD_STAT0_BUFFFULL |
59 		HDMI_IH_AHBDMAAUD_STAT0_BUFFEMPTY,
60 	HDMI_AHB_DMA_CONF0_INCR16 = 2 << 1,
61 	HDMI_AHB_DMA_CONF0_INCR8 = 1 << 1,
62 	HDMI_AHB_DMA_CONF0_INCR4 = 0,
63 	HDMI_AHB_DMA_CONF0_BURST_MODE = BIT(0),
64 	HDMI_AHB_DMA_MASK_DONE = BIT(7),
65 
66 	HDMI_REVISION_ID = 0x0001,
67 	HDMI_IH_AHBDMAAUD_STAT0 = 0x0109,
68 	HDMI_IH_MUTE_AHBDMAAUD_STAT0 = 0x0189,
69 	HDMI_FC_AUDICONF2 = 0x1027,
70 	HDMI_FC_AUDSCONF = 0x1063,
71 	HDMI_FC_AUDSCONF_LAYOUT1 = 1 << 0,
72 	HDMI_FC_AUDSCONF_LAYOUT0 = 0 << 0,
73 	HDMI_AHB_DMA_CONF0 = 0x3600,
74 	HDMI_AHB_DMA_START = 0x3601,
75 	HDMI_AHB_DMA_STOP = 0x3602,
76 	HDMI_AHB_DMA_THRSLD = 0x3603,
77 	HDMI_AHB_DMA_STRADDR0 = 0x3604,
78 	HDMI_AHB_DMA_STPADDR0 = 0x3608,
79 	HDMI_AHB_DMA_MASK = 0x3614,
80 	HDMI_AHB_DMA_POL = 0x3615,
81 	HDMI_AHB_DMA_CONF1 = 0x3616,
82 	HDMI_AHB_DMA_BUFFPOL = 0x361a,
83 };
84 
85 struct dw_hdmi_channel_conf {
86 	u8 conf1;
87 	u8 ca;
88 };
89 
90 /*
91  * The default mapping of ALSA channels to HDMI channels and speaker
92  * allocation bits.  Note that we can't do channel remapping here -
93  * channels must be in the same order.
94  *
95  * Mappings for alsa-lib pcm/surround*.conf files:
96  *
97  *		Front	Sur4.0	Sur4.1	Sur5.0	Sur5.1	Sur7.1
98  * Channels	2	4	6	6	6	8
99  *
100  * Our mapping from ALSA channel to CEA686D speaker name and HDMI channel:
101  *
102  *				Number of ALSA channels
103  * ALSA Channel	2	3	4	5	6	7	8
104  * 0		FL:0	=	=	=	=	=	=
105  * 1		FR:1	=	=	=	=	=	=
106  * 2			FC:3	RL:4	LFE:2	=	=	=
107  * 3				RR:5	RL:4	FC:3	=	=
108  * 4					RR:5	RL:4	=	=
109  * 5						RR:5	=	=
110  * 6							RC:6	=
111  * 7							RLC/FRC	RLC/FRC
112  */
113 static struct dw_hdmi_channel_conf default_hdmi_channel_config[7] = {
114 	{ 0x03, 0x00 },	/* FL,FR */
115 	{ 0x0b, 0x02 },	/* FL,FR,FC */
116 	{ 0x33, 0x08 },	/* FL,FR,RL,RR */
117 	{ 0x37, 0x09 },	/* FL,FR,LFE,RL,RR */
118 	{ 0x3f, 0x0b },	/* FL,FR,LFE,FC,RL,RR */
119 	{ 0x7f, 0x0f },	/* FL,FR,LFE,FC,RL,RR,RC */
120 	{ 0xff, 0x13 },	/* FL,FR,LFE,FC,RL,RR,[FR]RC,[FR]LC */
121 };
122 
123 struct snd_dw_hdmi {
124 	struct snd_card *card;
125 	struct snd_pcm *pcm;
126 	spinlock_t lock;
127 	struct dw_hdmi_audio_data data;
128 	struct snd_pcm_substream *substream;
129 	void (*reformat)(struct snd_dw_hdmi *, size_t, size_t);
130 	void *buf_src;
131 	void *buf_dst;
132 	dma_addr_t buf_addr;
133 	unsigned buf_offset;
134 	unsigned buf_period;
135 	unsigned buf_size;
136 	unsigned channels;
137 	u8 revision;
138 	u8 iec_offset;
139 	u8 cs[192][8];
140 };
141 
142 static void dw_hdmi_writel(u32 val, void __iomem *ptr)
143 {
144 	writeb_relaxed(val, ptr);
145 	writeb_relaxed(val >> 8, ptr + 1);
146 	writeb_relaxed(val >> 16, ptr + 2);
147 	writeb_relaxed(val >> 24, ptr + 3);
148 }
149 
150 /*
151  * Convert to hardware format: The userspace buffer contains IEC958 samples,
152  * with the PCUV bits in bits 31..28 and audio samples in bits 27..4.  We
153  * need these to be in bits 27..24, with the IEC B bit in bit 28, and audio
154  * samples in 23..0.
155  *
156  * Default preamble in bits 3..0: 8 = block start, 4 = even 2 = odd
157  *
158  * Ideally, we could do with having the data properly formatted in userspace.
159  */
160 static void dw_hdmi_reformat_iec958(struct snd_dw_hdmi *dw,
161 	size_t offset, size_t bytes)
162 {
163 	u32 *src = dw->buf_src + offset;
164 	u32 *dst = dw->buf_dst + offset;
165 	u32 *end = dw->buf_src + offset + bytes;
166 
167 	do {
168 		u32 b, sample = *src++;
169 
170 		b = (sample & 8) << (28 - 3);
171 
172 		sample >>= 4;
173 
174 		*dst++ = sample | b;
175 	} while (src < end);
176 }
177 
178 static u32 parity(u32 sample)
179 {
180 	sample ^= sample >> 16;
181 	sample ^= sample >> 8;
182 	sample ^= sample >> 4;
183 	sample ^= sample >> 2;
184 	sample ^= sample >> 1;
185 	return (sample & 1) << 27;
186 }
187 
188 static void dw_hdmi_reformat_s24(struct snd_dw_hdmi *dw,
189 	size_t offset, size_t bytes)
190 {
191 	u32 *src = dw->buf_src + offset;
192 	u32 *dst = dw->buf_dst + offset;
193 	u32 *end = dw->buf_src + offset + bytes;
194 
195 	do {
196 		unsigned i;
197 		u8 *cs;
198 
199 		cs = dw->cs[dw->iec_offset++];
200 		if (dw->iec_offset >= 192)
201 			dw->iec_offset = 0;
202 
203 		i = dw->channels;
204 		do {
205 			u32 sample = *src++;
206 
207 			sample &= ~0xff000000;
208 			sample |= *cs++ << 24;
209 			sample |= parity(sample & ~0xf8000000);
210 
211 			*dst++ = sample;
212 		} while (--i);
213 	} while (src < end);
214 }
215 
216 static void dw_hdmi_create_cs(struct snd_dw_hdmi *dw,
217 	struct snd_pcm_runtime *runtime)
218 {
219 	u8 cs[4];
220 	unsigned ch, i, j;
221 
222 	snd_pcm_create_iec958_consumer(runtime, cs, sizeof(cs));
223 
224 	memset(dw->cs, 0, sizeof(dw->cs));
225 
226 	for (ch = 0; ch < 8; ch++) {
227 		cs[2] &= ~IEC958_AES2_CON_CHANNEL;
228 		cs[2] |= (ch + 1) << 4;
229 
230 		for (i = 0; i < ARRAY_SIZE(cs); i++) {
231 			unsigned c = cs[i];
232 
233 			for (j = 0; j < 8; j++, c >>= 1)
234 				dw->cs[i * 8 + j][ch] = (c & 1) << 2;
235 		}
236 	}
237 	dw->cs[0][0] |= BIT(4);
238 }
239 
240 static void dw_hdmi_start_dma(struct snd_dw_hdmi *dw)
241 {
242 	void __iomem *base = dw->data.base;
243 	unsigned offset = dw->buf_offset;
244 	unsigned period = dw->buf_period;
245 	u32 start, stop;
246 
247 	dw->reformat(dw, offset, period);
248 
249 	/* Clear all irqs before enabling irqs and starting DMA */
250 	writeb_relaxed(HDMI_IH_AHBDMAAUD_STAT0_ALL,
251 		       base + HDMI_IH_AHBDMAAUD_STAT0);
252 
253 	start = dw->buf_addr + offset;
254 	stop = start + period - 1;
255 
256 	/* Setup the hardware start/stop addresses */
257 	dw_hdmi_writel(start, base + HDMI_AHB_DMA_STRADDR0);
258 	dw_hdmi_writel(stop, base + HDMI_AHB_DMA_STPADDR0);
259 
260 	writeb_relaxed((u8)~HDMI_AHB_DMA_MASK_DONE, base + HDMI_AHB_DMA_MASK);
261 	writeb(HDMI_AHB_DMA_START_START, base + HDMI_AHB_DMA_START);
262 
263 	offset += period;
264 	if (offset >= dw->buf_size)
265 		offset = 0;
266 	dw->buf_offset = offset;
267 }
268 
269 static void dw_hdmi_stop_dma(struct snd_dw_hdmi *dw)
270 {
271 	/* Disable interrupts before disabling DMA */
272 	writeb_relaxed(~0, dw->data.base + HDMI_AHB_DMA_MASK);
273 	writeb_relaxed(HDMI_AHB_DMA_STOP_STOP, dw->data.base + HDMI_AHB_DMA_STOP);
274 }
275 
276 static irqreturn_t snd_dw_hdmi_irq(int irq, void *data)
277 {
278 	struct snd_dw_hdmi *dw = data;
279 	struct snd_pcm_substream *substream;
280 	unsigned stat;
281 
282 	stat = readb_relaxed(dw->data.base + HDMI_IH_AHBDMAAUD_STAT0);
283 	if (!stat)
284 		return IRQ_NONE;
285 
286 	writeb_relaxed(stat, dw->data.base + HDMI_IH_AHBDMAAUD_STAT0);
287 
288 	substream = dw->substream;
289 	if (stat & HDMI_IH_AHBDMAAUD_STAT0_DONE && substream) {
290 		snd_pcm_period_elapsed(substream);
291 
292 		spin_lock(&dw->lock);
293 		if (dw->substream)
294 			dw_hdmi_start_dma(dw);
295 		spin_unlock(&dw->lock);
296 	}
297 
298 	return IRQ_HANDLED;
299 }
300 
301 static struct snd_pcm_hardware dw_hdmi_hw = {
302 	.info = SNDRV_PCM_INFO_INTERLEAVED |
303 		SNDRV_PCM_INFO_BLOCK_TRANSFER |
304 		SNDRV_PCM_INFO_MMAP |
305 		SNDRV_PCM_INFO_MMAP_VALID,
306 	.formats = SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_LE |
307 		   SNDRV_PCM_FMTBIT_S24_LE,
308 	.rates = SNDRV_PCM_RATE_32000 |
309 		 SNDRV_PCM_RATE_44100 |
310 		 SNDRV_PCM_RATE_48000 |
311 		 SNDRV_PCM_RATE_88200 |
312 		 SNDRV_PCM_RATE_96000 |
313 		 SNDRV_PCM_RATE_176400 |
314 		 SNDRV_PCM_RATE_192000,
315 	.channels_min = 2,
316 	.channels_max = 8,
317 	.buffer_bytes_max = 1024 * 1024,
318 	.period_bytes_min = 256,
319 	.period_bytes_max = 8192,	/* ERR004323: must limit to 8k */
320 	.periods_min = 2,
321 	.periods_max = 16,
322 	.fifo_size = 0,
323 };
324 
325 static int dw_hdmi_open(struct snd_pcm_substream *substream)
326 {
327 	struct snd_pcm_runtime *runtime = substream->runtime;
328 	struct snd_dw_hdmi *dw = substream->private_data;
329 	void __iomem *base = dw->data.base;
330 	int ret;
331 
332 	runtime->hw = dw_hdmi_hw;
333 
334 	ret = snd_pcm_hw_constraint_eld(runtime, dw->data.eld);
335 	if (ret < 0)
336 		return ret;
337 
338 	ret = snd_pcm_limit_hw_rates(runtime);
339 	if (ret < 0)
340 		return ret;
341 
342 	ret = snd_pcm_hw_constraint_integer(runtime,
343 					    SNDRV_PCM_HW_PARAM_PERIODS);
344 	if (ret < 0)
345 		return ret;
346 
347 	/* Limit the buffer size to the size of the preallocated buffer */
348 	ret = snd_pcm_hw_constraint_minmax(runtime,
349 					   SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
350 					   0, substream->dma_buffer.bytes);
351 	if (ret < 0)
352 		return ret;
353 
354 	/* Clear FIFO */
355 	writeb_relaxed(HDMI_AHB_DMA_CONF0_SW_FIFO_RST,
356 		       base + HDMI_AHB_DMA_CONF0);
357 
358 	/* Configure interrupt polarities */
359 	writeb_relaxed(~0, base + HDMI_AHB_DMA_POL);
360 	writeb_relaxed(~0, base + HDMI_AHB_DMA_BUFFPOL);
361 
362 	/* Keep interrupts masked, and clear any pending */
363 	writeb_relaxed(~0, base + HDMI_AHB_DMA_MASK);
364 	writeb_relaxed(~0, base + HDMI_IH_AHBDMAAUD_STAT0);
365 
366 	ret = request_irq(dw->data.irq, snd_dw_hdmi_irq, IRQF_SHARED,
367 			  "dw-hdmi-audio", dw);
368 	if (ret)
369 		return ret;
370 
371 	/* Un-mute done interrupt */
372 	writeb_relaxed(HDMI_IH_MUTE_AHBDMAAUD_STAT0_ALL &
373 		       ~HDMI_IH_MUTE_AHBDMAAUD_STAT0_DONE,
374 		       base + HDMI_IH_MUTE_AHBDMAAUD_STAT0);
375 
376 	return 0;
377 }
378 
379 static int dw_hdmi_close(struct snd_pcm_substream *substream)
380 {
381 	struct snd_dw_hdmi *dw = substream->private_data;
382 
383 	/* Mute all interrupts */
384 	writeb_relaxed(HDMI_IH_MUTE_AHBDMAAUD_STAT0_ALL,
385 		       dw->data.base + HDMI_IH_MUTE_AHBDMAAUD_STAT0);
386 
387 	free_irq(dw->data.irq, dw);
388 
389 	return 0;
390 }
391 
392 static int dw_hdmi_hw_free(struct snd_pcm_substream *substream)
393 {
394 	return snd_pcm_lib_free_vmalloc_buffer(substream);
395 }
396 
397 static int dw_hdmi_hw_params(struct snd_pcm_substream *substream,
398 	struct snd_pcm_hw_params *params)
399 {
400 	/* Allocate the PCM runtime buffer, which is exposed to userspace. */
401 	return snd_pcm_lib_alloc_vmalloc_buffer(substream,
402 						params_buffer_bytes(params));
403 }
404 
405 static int dw_hdmi_prepare(struct snd_pcm_substream *substream)
406 {
407 	struct snd_pcm_runtime *runtime = substream->runtime;
408 	struct snd_dw_hdmi *dw = substream->private_data;
409 	u8 threshold, conf0, conf1, layout, ca;
410 
411 	/* Setup as per 3.0.5 FSL 4.1.0 BSP */
412 	switch (dw->revision) {
413 	case 0x0a:
414 		conf0 = HDMI_AHB_DMA_CONF0_BURST_MODE |
415 			HDMI_AHB_DMA_CONF0_INCR4;
416 		if (runtime->channels == 2)
417 			threshold = 126;
418 		else
419 			threshold = 124;
420 		break;
421 	case 0x1a:
422 		conf0 = HDMI_AHB_DMA_CONF0_BURST_MODE |
423 			HDMI_AHB_DMA_CONF0_INCR8;
424 		threshold = 128;
425 		break;
426 	default:
427 		/* NOTREACHED */
428 		return -EINVAL;
429 	}
430 
431 	dw_hdmi_set_sample_rate(dw->data.hdmi, runtime->rate);
432 
433 	/* Minimum number of bytes in the fifo. */
434 	runtime->hw.fifo_size = threshold * 32;
435 
436 	conf0 |= HDMI_AHB_DMA_CONF0_EN_HLOCK;
437 	conf1 = default_hdmi_channel_config[runtime->channels - 2].conf1;
438 	ca = default_hdmi_channel_config[runtime->channels - 2].ca;
439 
440 	/*
441 	 * For >2 channel PCM audio, we need to select layout 1
442 	 * and set an appropriate channel map.
443 	 */
444 	if (runtime->channels > 2)
445 		layout = HDMI_FC_AUDSCONF_LAYOUT1;
446 	else
447 		layout = HDMI_FC_AUDSCONF_LAYOUT0;
448 
449 	writeb_relaxed(threshold, dw->data.base + HDMI_AHB_DMA_THRSLD);
450 	writeb_relaxed(conf0, dw->data.base + HDMI_AHB_DMA_CONF0);
451 	writeb_relaxed(conf1, dw->data.base + HDMI_AHB_DMA_CONF1);
452 	writeb_relaxed(layout, dw->data.base + HDMI_FC_AUDSCONF);
453 	writeb_relaxed(ca, dw->data.base + HDMI_FC_AUDICONF2);
454 
455 	switch (runtime->format) {
456 	case SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE:
457 		dw->reformat = dw_hdmi_reformat_iec958;
458 		break;
459 	case SNDRV_PCM_FORMAT_S24_LE:
460 		dw_hdmi_create_cs(dw, runtime);
461 		dw->reformat = dw_hdmi_reformat_s24;
462 		break;
463 	}
464 	dw->iec_offset = 0;
465 	dw->channels = runtime->channels;
466 	dw->buf_src  = runtime->dma_area;
467 	dw->buf_dst  = substream->dma_buffer.area;
468 	dw->buf_addr = substream->dma_buffer.addr;
469 	dw->buf_period = snd_pcm_lib_period_bytes(substream);
470 	dw->buf_size = snd_pcm_lib_buffer_bytes(substream);
471 
472 	return 0;
473 }
474 
475 static int dw_hdmi_trigger(struct snd_pcm_substream *substream, int cmd)
476 {
477 	struct snd_dw_hdmi *dw = substream->private_data;
478 	unsigned long flags;
479 	int ret = 0;
480 
481 	switch (cmd) {
482 	case SNDRV_PCM_TRIGGER_START:
483 		spin_lock_irqsave(&dw->lock, flags);
484 		dw->buf_offset = 0;
485 		dw->substream = substream;
486 		dw_hdmi_start_dma(dw);
487 		dw_hdmi_audio_enable(dw->data.hdmi);
488 		spin_unlock_irqrestore(&dw->lock, flags);
489 		substream->runtime->delay = substream->runtime->period_size;
490 		break;
491 
492 	case SNDRV_PCM_TRIGGER_STOP:
493 		spin_lock_irqsave(&dw->lock, flags);
494 		dw->substream = NULL;
495 		dw_hdmi_stop_dma(dw);
496 		dw_hdmi_audio_disable(dw->data.hdmi);
497 		spin_unlock_irqrestore(&dw->lock, flags);
498 		break;
499 
500 	default:
501 		ret = -EINVAL;
502 		break;
503 	}
504 
505 	return ret;
506 }
507 
508 static snd_pcm_uframes_t dw_hdmi_pointer(struct snd_pcm_substream *substream)
509 {
510 	struct snd_pcm_runtime *runtime = substream->runtime;
511 	struct snd_dw_hdmi *dw = substream->private_data;
512 
513 	/*
514 	 * We are unable to report the exact hardware position as
515 	 * reading the 32-bit DMA position using 8-bit reads is racy.
516 	 */
517 	return bytes_to_frames(runtime, dw->buf_offset);
518 }
519 
520 static const struct snd_pcm_ops snd_dw_hdmi_ops = {
521 	.open = dw_hdmi_open,
522 	.close = dw_hdmi_close,
523 	.ioctl = snd_pcm_lib_ioctl,
524 	.hw_params = dw_hdmi_hw_params,
525 	.hw_free = dw_hdmi_hw_free,
526 	.prepare = dw_hdmi_prepare,
527 	.trigger = dw_hdmi_trigger,
528 	.pointer = dw_hdmi_pointer,
529 	.page = snd_pcm_lib_get_vmalloc_page,
530 };
531 
532 static int snd_dw_hdmi_probe(struct platform_device *pdev)
533 {
534 	const struct dw_hdmi_audio_data *data = pdev->dev.platform_data;
535 	struct device *dev = pdev->dev.parent;
536 	struct snd_dw_hdmi *dw;
537 	struct snd_card *card;
538 	struct snd_pcm *pcm;
539 	unsigned revision;
540 	int ret;
541 
542 	writeb_relaxed(HDMI_IH_MUTE_AHBDMAAUD_STAT0_ALL,
543 		       data->base + HDMI_IH_MUTE_AHBDMAAUD_STAT0);
544 	revision = readb_relaxed(data->base + HDMI_REVISION_ID);
545 	if (revision != 0x0a && revision != 0x1a) {
546 		dev_err(dev, "dw-hdmi-audio: unknown revision 0x%02x\n",
547 			revision);
548 		return -ENXIO;
549 	}
550 
551 	ret = snd_card_new(dev, SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1,
552 			      THIS_MODULE, sizeof(struct snd_dw_hdmi), &card);
553 	if (ret < 0)
554 		return ret;
555 
556 	strlcpy(card->driver, DRIVER_NAME, sizeof(card->driver));
557 	strlcpy(card->shortname, "DW-HDMI", sizeof(card->shortname));
558 	snprintf(card->longname, sizeof(card->longname),
559 		 "%s rev 0x%02x, irq %d", card->shortname, revision,
560 		 data->irq);
561 
562 	dw = card->private_data;
563 	dw->card = card;
564 	dw->data = *data;
565 	dw->revision = revision;
566 
567 	spin_lock_init(&dw->lock);
568 
569 	ret = snd_pcm_new(card, "DW HDMI", 0, 1, 0, &pcm);
570 	if (ret < 0)
571 		goto err;
572 
573 	dw->pcm = pcm;
574 	pcm->private_data = dw;
575 	strlcpy(pcm->name, DRIVER_NAME, sizeof(pcm->name));
576 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_dw_hdmi_ops);
577 
578 	/*
579 	 * To support 8-channel 96kHz audio reliably, we need 512k
580 	 * to satisfy alsa with our restricted period (ERR004323).
581 	 */
582 	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
583 			dev, 128 * 1024, 1024 * 1024);
584 
585 	ret = snd_card_register(card);
586 	if (ret < 0)
587 		goto err;
588 
589 	platform_set_drvdata(pdev, dw);
590 
591 	return 0;
592 
593 err:
594 	snd_card_free(card);
595 	return ret;
596 }
597 
598 static int snd_dw_hdmi_remove(struct platform_device *pdev)
599 {
600 	struct snd_dw_hdmi *dw = platform_get_drvdata(pdev);
601 
602 	snd_card_free(dw->card);
603 
604 	return 0;
605 }
606 
607 #if defined(CONFIG_PM_SLEEP) && defined(IS_NOT_BROKEN)
608 /*
609  * This code is fine, but requires implementation in the dw_hdmi_trigger()
610  * method which is currently missing as I have no way to test this.
611  */
612 static int snd_dw_hdmi_suspend(struct device *dev)
613 {
614 	struct snd_dw_hdmi *dw = dev_get_drvdata(dev);
615 
616 	snd_power_change_state(dw->card, SNDRV_CTL_POWER_D3cold);
617 	snd_pcm_suspend_all(dw->pcm);
618 
619 	return 0;
620 }
621 
622 static int snd_dw_hdmi_resume(struct device *dev)
623 {
624 	struct snd_dw_hdmi *dw = dev_get_drvdata(dev);
625 
626 	snd_power_change_state(dw->card, SNDRV_CTL_POWER_D0);
627 
628 	return 0;
629 }
630 
631 static SIMPLE_DEV_PM_OPS(snd_dw_hdmi_pm, snd_dw_hdmi_suspend,
632 			 snd_dw_hdmi_resume);
633 #define PM_OPS &snd_dw_hdmi_pm
634 #else
635 #define PM_OPS NULL
636 #endif
637 
638 static struct platform_driver snd_dw_hdmi_driver = {
639 	.probe	= snd_dw_hdmi_probe,
640 	.remove	= snd_dw_hdmi_remove,
641 	.driver	= {
642 		.name = DRIVER_NAME,
643 		.pm = PM_OPS,
644 	},
645 };
646 
647 module_platform_driver(snd_dw_hdmi_driver);
648 
649 MODULE_AUTHOR("Russell King <rmk+kernel@arm.linux.org.uk>");
650 MODULE_DESCRIPTION("Synopsis Designware HDMI AHB ALSA interface");
651 MODULE_LICENSE("GPL v2");
652 MODULE_ALIAS("platform:" DRIVER_NAME);
653