cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

dw-hdmi-ahb-audio.c (16587B)


      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 */
     26enum {
     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
     78struct 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 */
    106static 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
    116struct 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
    135static 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 */
    153static 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
    171static 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
    181static 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
    209static 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
    233static 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
    262static 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
    269static 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
    294static 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
    318static 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
    376static 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
    389static int dw_hdmi_hw_free(struct snd_pcm_substream *substream)
    390{
    391	return snd_pcm_lib_free_vmalloc_buffer(substream);
    392}
    393
    394static 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
    402static 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
    464static 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
    497static 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
    509static 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
    521static 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	strlcpy(card->driver, DRIVER_NAME, sizeof(card->driver));
    546	strlcpy(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	strlcpy(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
    582err:
    583	snd_card_free(card);
    584	return ret;
    585}
    586
    587static 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 */
    601static 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
    610static 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
    619static 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
    626static 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
    635module_platform_driver(snd_dw_hdmi_driver);
    636
    637MODULE_AUTHOR("Russell King <rmk+kernel@armlinux.org.uk>");
    638MODULE_DESCRIPTION("Synopsis Designware HDMI AHB ALSA interface");
    639MODULE_LICENSE("GPL v2");
    640MODULE_ALIAS("platform:" DRIVER_NAME);