[PATCH RFC 44/46] imx-drm: dw-hdmi-audio: add audio driver

[rmk+kernel@arm.linux.org.uk (Russell King)]

Add ALSA based HDMI audio driver for imx-hdmi.  The imx-hdmi is a
Synopsis DesignWare module, so let's name it after that.  The only
buffer format supported is its own special IEC958 based format, which
is not compatible with any ALSA format.  To avoid doing too much data
manipulation within the driver, we support only ALSAs IEC958 LE, and
24-bit PCM formats for 2 to 6 channels.

This allows us to modify the buffer in place as each period is passed
for DMA without needing a separate buffer.

A more desirable solution would be to have this conversion in userspace,
but ALSA does not appear to allow such transformations outside of
libasound itself.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/staging/imx-drm/Makefile        |    3 +-
 drivers/staging/imx-drm/dw-hdmi-audio.c |  500 +++++++++++++++++++++++++++++++
 drivers/staging/imx-drm/dw-hdmi-audio.h |   13 +
 drivers/staging/imx-drm/imx-hdmi.c      |   21 ++
 drivers/staging/imx-drm/imx-hdmi.h      |    4 +
 5 files changed, 540 insertions(+), 1 deletions(-)
 create mode 100644 drivers/staging/imx-drm/dw-hdmi-audio.c
 create mode 100644 drivers/staging/imx-drm/dw-hdmi-audio.h

diff --git a/drivers/staging/imx-drm/Makefile b/drivers/staging/imx-drm/Makefile
index 129e3a3f59f1..f554aa631993 100644
--- a/drivers/staging/imx-drm/Makefile
+++ b/drivers/staging/imx-drm/Makefile
@@ -1,5 +1,6 @@
 
 imxdrm-objs := imx-drm-core.o
+imxhdmi-objs := imx-hdmi.o dw-hdmi-audio.o
 
 obj-$(CONFIG_DRM_IMX) += imxdrm.o
 
@@ -10,4 +11,4 @@ obj-$(CONFIG_DRM_IMX_IPUV3_CORE) += ipu-v3/
 
 imx-ipuv3-crtc-objs  := ipuv3-crtc.o ipuv3-plane.o
 obj-$(CONFIG_DRM_IMX_IPUV3)	+= imx-ipuv3-crtc.o
-obj-$(CONFIG_DRM_IMX_HDMI) += imx-hdmi.o
+obj-$(CONFIG_DRM_IMX_HDMI) += imxhdmi.o
diff --git a/drivers/staging/imx-drm/dw-hdmi-audio.c b/drivers/staging/imx-drm/dw-hdmi-audio.c
new file mode 100644
index 000000000000..946055d2a975
--- /dev/null
+++ b/drivers/staging/imx-drm/dw-hdmi-audio.c
@@ -0,0 +1,500 @@
+/*
+ * DesignWare HDMI audio driver
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Written and tested against the (alleged) DW HDMI Tx found in iMX6S.
+ */
+#include <linux/io.h>
+#include <linux/interrupt.h>
+
+#include <sound/asoundef.h>
+#include <sound/core.h>
+#include <sound/initval.h>
+#include <sound/pcm.h>
+
+#include "imx-hdmi.h"
+#include "dw-hdmi-audio.h"
+
+#define DRIVER_NAME "dw-hdmi-audio"
+
+/* Provide some bits rather than bit offsets */
+enum {
+	HDMI_AHB_DMA_CONF0_SW_FIFO_RST = HDMI_AHB_DMA_CONF0_SW_FIFO_RST_MASK,
+	HDMI_AHB_DMA_CONF0_EN_HLOCK = HDMI_AHB_DMA_CONF0_EN_HLOCK_MASK,
+	HDMI_AHB_DMA_START_START = BIT(HDMI_AHB_DMA_START_START_OFFSET),
+	HDMI_AHB_DMA_STOP_STOP = BIT(HDMI_AHB_DMA_STOP_STOP_OFFSET),
+	HDMI_IH_MUTE_AHBDMAAUD_STAT0_ALL =
+		HDMI_IH_MUTE_AHBDMAAUD_STAT0_ERROR |
+		HDMI_IH_MUTE_AHBDMAAUD_STAT0_LOST |
+		HDMI_IH_MUTE_AHBDMAAUD_STAT0_RETRY |
+		HDMI_IH_MUTE_AHBDMAAUD_STAT0_DONE |
+		HDMI_IH_MUTE_AHBDMAAUD_STAT0_BUFFFULL |
+		HDMI_IH_MUTE_AHBDMAAUD_STAT0_BUFFEMPTY,
+	HDMI_IH_AHBDMAAUD_STAT0_ALL =
+		HDMI_IH_AHBDMAAUD_STAT0_ERROR |
+		HDMI_IH_AHBDMAAUD_STAT0_LOST |
+		HDMI_IH_AHBDMAAUD_STAT0_RETRY |
+		HDMI_IH_AHBDMAAUD_STAT0_DONE |
+		HDMI_IH_AHBDMAAUD_STAT0_BUFFFULL |
+		HDMI_IH_AHBDMAAUD_STAT0_BUFFEMPTY,
+};
+
+struct snd_dw_hdmi {
+	struct snd_card *card;
+	struct snd_pcm *pcm;
+	void __iomem *base;
+	int irq;
+	struct imx_hdmi *hdmi;
+	struct snd_pcm_substream *substream;
+	void (*reformat)(struct snd_dw_hdmi *, size_t, size_t);
+	void *buf_base;
+	dma_addr_t buf_addr;
+	unsigned buf_offset;
+	unsigned buf_period;
+	unsigned buf_size;
+	unsigned channels;
+	uint8_t revision;
+	uint8_t iec_offset;
+	uint8_t cs[192][8];
+};
+
+static void dw_hdmi_writeb(unsigned long val, void __iomem *ptr)
+{
+	writeb(val, ptr);
+}
+
+static unsigned dw_hdmi_readb(void __iomem *ptr)
+{
+	return readb(ptr);
+}
+
+static void dw_hdmi_writel(unsigned long val, void __iomem *ptr)
+{
+	writeb_relaxed(val, ptr);
+	writeb_relaxed(val >> 8, ptr + 1);
+	writeb_relaxed(val >> 16, ptr + 2);
+	writeb_relaxed(val >> 24, ptr + 3);
+}
+
+/*
+ * Convert to hardware format: The userspace buffer contains IEC958 samples,
+ * with the PCUV bits in bits 31..28 and audio samples in bits 27..4.  We
+ * need these to be in bits 27..24, with the IEC B bit in bit 28, and audio
+ * samples in 23..0.
+ *
+ * Default preamble in bits 3..0: 8 = block start, 4 = even 2 = odd
+ *
+ * Ideally, we could do with having the data properly formatted in userspace.
+ */
+static void dw_hdmi_reformat_iec958(struct snd_dw_hdmi *dw,
+	size_t offset, size_t bytes)
+{
+	uint32_t *ptr = dw->buf_base + offset;
+	uint32_t *end = dw->buf_base + offset + bytes;
+
+	do {
+		uint32_t b, sample = *ptr;
+
+		b = (sample & 8) << (28 - 3);
+
+		sample >>= 4;
+
+		*ptr++ = sample | b;
+	} while (ptr < end);
+}
+
+static uint32_t parity(uint32_t sample)
+{
+	sample ^= sample >> 16;
+	sample ^= sample >> 8;
+	sample ^= sample >> 4;
+	sample ^= sample >> 2;
+	sample ^= sample >> 1;
+	return (sample & 1) << 27;
+}
+
+static void dw_hdmi_reformat_s24(struct snd_dw_hdmi *dw,
+	size_t offset, size_t bytes)
+{
+	uint32_t *ptr = dw->buf_base + offset;
+	uint32_t *end = dw->buf_base + offset + bytes;
+
+	do {
+		unsigned i;
+		uint8_t *cs;
+
+		cs = dw->cs[dw->iec_offset++];
+		if (dw->iec_offset >= 192)
+			dw->iec_offset = 0;
+
+		i = dw->channels;
+		do {
+			uint32_t sample = *ptr;
+
+			sample &= ~0xff000000;
+			sample |= *cs++ << 24;
+			sample |= parity(sample & ~0xf8000000);
+
+			*ptr++ = sample;
+		} while (--i);
+	} while (ptr < end);
+}
+
+static void dw_hdmi_create_cs(struct snd_dw_hdmi *dw,
+	struct snd_pcm_runtime *runtime)
+{
+	uint8_t cs[3];
+	unsigned ch, i, j;
+
+	cs[0] = IEC958_AES0_CON_NOT_COPYRIGHT | IEC958_AES0_CON_EMPHASIS_NONE;
+	cs[1] = IEC958_AES1_CON_GENERAL;
+	cs[2] = IEC958_AES2_CON_SOURCE_UNSPEC;
+	cs[3] = IEC958_AES3_CON_CLOCK_1000PPM;
+
+	switch (runtime->rate) {
+	case 32000:
+		cs[3] |= IEC958_AES3_CON_FS_32000;
+		break;
+	case 44100:
+		cs[3] |= IEC958_AES3_CON_FS_44100;
+		break;
+	case 48000:
+		cs[3] |= IEC958_AES3_CON_FS_48000;
+		break;
+	case 88200:
+		cs[3] |= IEC958_AES3_CON_FS_88200;
+		break;
+	case 96000:
+		cs[3] |= IEC958_AES3_CON_FS_96000;
+		break;
+	case 176400:
+		cs[3] |= IEC958_AES3_CON_FS_176400;
+		break;
+	case 192000:
+		cs[3] |= IEC958_AES3_CON_FS_192000;
+		break;
+	}
+
+	memset(dw->cs, 0, sizeof(dw->cs));
+
+	for (ch = 0; ch < 8; ch++) {
+		cs[2] &= ~IEC958_AES2_CON_CHANNEL;
+		cs[2] |= (ch + 1) << 4;
+
+		for (i = 0; i < ARRAY_SIZE(cs); i++) {
+			unsigned c = cs[i];
+
+			for (j = 0; j < 8; j++, c >>= 1)
+				dw->cs[i * 8 + j][ch] = (c & 1) << 2;
+		}
+	}
+	dw->cs[0][0] |= BIT(4);
+}
+
+static void dw_hdmi_start_dma(struct snd_dw_hdmi *dw)
+{
+	unsigned long start, stop;
+
+	start = dw->buf_addr + dw->buf_offset;
+	stop = start + dw->buf_period - 1;
+
+	dw->reformat(dw, dw->buf_offset, dw->buf_period);
+
+	/* Setup the hardware start/stop addresses */
+	dw_hdmi_writel(start, dw->base + HDMI_AHB_DMA_STRADDR0);
+	dw_hdmi_writel(stop, dw->base + HDMI_AHB_DMA_STPADDR0);
+
+	/* Clear all irqs before enabling irqs and starting DMA */
+	dw_hdmi_writeb(HDMI_IH_AHBDMAAUD_STAT0_ALL,
+		       dw->base + HDMI_IH_AHBDMAAUD_STAT0);
+	dw_hdmi_writeb(~HDMI_AHB_DMA_DONE, dw->base + HDMI_AHB_DMA_MASK);
+	dw_hdmi_writeb(HDMI_AHB_DMA_START_START, dw->base + HDMI_AHB_DMA_START);
+}
+
+static void dw_hdmi_stop_dma(struct snd_dw_hdmi *dw)
+{
+	dw->substream = NULL;
+
+	/* Disable interrupts before disabling DMA */
+	dw_hdmi_writeb(~0, dw->base + HDMI_AHB_DMA_MASK);
+	dw_hdmi_writeb(HDMI_AHB_DMA_STOP_STOP, dw->base + HDMI_AHB_DMA_STOP);
+}
+
+static irqreturn_t snd_dw_hdmi_irq(int irq, void *data)
+{
+	struct snd_dw_hdmi *dw = data;
+	struct snd_pcm_substream *substream;
+	unsigned stat;
+
+	stat = dw_hdmi_readb(dw->base + HDMI_IH_AHBDMAAUD_STAT0);
+	if (!stat)
+		return IRQ_NONE;
+
+	dw_hdmi_writeb(stat, dw->base + HDMI_IH_AHBDMAAUD_STAT0);
+
+	substream = dw->substream;
+	if (stat & HDMI_IH_AHBDMAAUD_STAT0_DONE && substream) {
+		dw->buf_offset += dw->buf_period;
+		if (dw->buf_offset >= dw->buf_size)
+			dw->buf_offset = 0;
+
+		snd_pcm_period_elapsed(substream);
+		if (dw->substream) {
+			dw_hdmi_start_dma(dw);
+		}
+	}
+
+	return IRQ_HANDLED;
+}
+
+static struct snd_pcm_hardware dw_hdmi_hw = {
+	.info = SNDRV_PCM_INFO_INTERLEAVED |
+		SNDRV_PCM_INFO_BLOCK_TRANSFER |
+		SNDRV_PCM_INFO_MMAP |
+		SNDRV_PCM_INFO_MMAP_VALID,
+	.formats = SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_LE |
+		   SNDRV_PCM_FMTBIT_S24_LE,
+	.rates = SNDRV_PCM_RATE_32000 |
+		 SNDRV_PCM_RATE_44100 |
+		 SNDRV_PCM_RATE_48000 |
+		 SNDRV_PCM_RATE_88200 |
+		 SNDRV_PCM_RATE_96000 |
+		 SNDRV_PCM_RATE_176400 |
+		 SNDRV_PCM_RATE_192000,
+	.channels_min = 2,
+	.channels_max = 8,
+	.buffer_bytes_max = 64 * 1024,
+	.period_bytes_min = 256,
+	.period_bytes_max = 8192,	/* ERR004323: must limit to 8k */
+	.periods_min = 2,
+	.periods_max = 16,
+	.fifo_size = 0,
+};
+
+static int dw_hdmi_open(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_dw_hdmi *dw = substream->private_data;
+	int ret;
+
+	/* Clear FIFO */
+	dw_hdmi_writeb(HDMI_AHB_DMA_CONF0_SW_FIFO_RST,
+		       dw->base + HDMI_AHB_DMA_CONF0);
+
+	/* Configure interrupt polarities */
+	dw_hdmi_writeb(~0, dw->base + HDMI_AHB_DMA_POL);
+	dw_hdmi_writeb(~0, dw->base + HDMI_AHB_DMA_BUFFPOL);
+
+	/* Keep interrupts masked */
+	dw_hdmi_writeb(~0, dw->base + HDMI_AHB_DMA_MASK);
+
+	ret = request_irq(dw->irq, snd_dw_hdmi_irq, IRQF_SHARED,
+			  "dw-hdmi-audio", dw);
+	if (ret)
+		return ret;
+
+	/* Un-mute done interrupt */
+	dw_hdmi_writeb(HDMI_IH_MUTE_AHBDMAAUD_STAT0_ALL &
+		       ~HDMI_IH_MUTE_AHBDMAAUD_STAT0_DONE,
+		       dw->base + HDMI_IH_MUTE_AHBDMAAUD_STAT0);
+
+	runtime->hw = dw_hdmi_hw;
+	snd_pcm_limit_hw_rates(runtime);
+
+	return 0;
+}
+
+static int dw_hdmi_close(struct snd_pcm_substream *substream)
+{
+	struct snd_dw_hdmi *dw = substream->private_data;
+
+	/* Mute all interrupts */
+	dw_hdmi_writeb(HDMI_IH_MUTE_AHBDMAAUD_STAT0_ALL,
+		       dw->base + HDMI_IH_MUTE_AHBDMAAUD_STAT0);
+
+	free_irq(dw->irq, dw);
+
+	return 0;
+}
+
+static int dw_hdmi_hw_free(struct snd_pcm_substream *substream)
+{
+	return snd_pcm_lib_free_pages(substream);
+}
+
+static int dw_hdmi_hw_params(struct snd_pcm_substream *substream,
+	struct snd_pcm_hw_params *params)
+{
+	return snd_pcm_lib_malloc_pages(substream,
+					params_buffer_bytes(params));
+}
+
+static int dw_hdmi_prepare(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_dw_hdmi *dw = substream->private_data;
+	uint8_t threshold, conf0, conf1;
+
+	/* Setup as per 3.0.5 FSL 4.1.0 BSP */
+	switch (dw->revision) {
+	case 0x0a:
+		conf0 = HDMI_AHB_DMA_CONF0_BURST_MODE |
+			HDMI_AHB_DMA_CONF0_INCR4;
+		if (runtime->channels == 2)
+			threshold = 126;
+		else
+			threshold = 124;
+		break;
+	case 0x1a:
+		conf0 = HDMI_AHB_DMA_CONF0_BURST_MODE |
+			HDMI_AHB_DMA_CONF0_INCR8;
+		threshold = 128;
+		break;
+	default:
+		/* NOTREACHED */
+		return -EINVAL;
+	}
+
+	imx_hdmi_set_sample_rate(dw->hdmi, runtime->rate);
+
+	/* Minimum number of bytes in the fifo. */
+	runtime->hw.fifo_size = threshold * 32;
+
+	conf0 |= HDMI_AHB_DMA_CONF0_EN_HLOCK;
+	conf1 = (1 << runtime->channels) - 1;
+
+	dw_hdmi_writeb(threshold, dw->base + HDMI_AHB_DMA_THRSLD);
+	dw_hdmi_writeb(conf0, dw->base + HDMI_AHB_DMA_CONF0);
+	dw_hdmi_writeb(conf1, dw->base + HDMI_AHB_DMA_CONF1);
+
+	switch (runtime->format) {
+	case SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE:
+		dw->reformat = dw_hdmi_reformat_iec958;
+		break;
+	case SNDRV_PCM_FORMAT_S24_LE:
+		dw_hdmi_create_cs(dw, runtime);
+		dw->reformat = dw_hdmi_reformat_s24;
+		break;
+	}
+	dw->iec_offset = 0;
+	dw->channels = runtime->channels;
+	dw->buf_base = runtime->dma_area;
+	dw->buf_addr = runtime->dma_addr;
+	dw->buf_period = snd_pcm_lib_period_bytes(substream);
+	dw->buf_size = snd_pcm_lib_buffer_bytes(substream);
+
+	return 0;
+}
+
+static int dw_hdmi_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+	struct snd_dw_hdmi *dw = substream->private_data;
+	int ret = 0;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+		dw->buf_offset = 0;
+		dw->substream = substream;
+		dw_hdmi_start_dma(dw);
+		break;
+
+	case SNDRV_PCM_TRIGGER_STOP:
+		dw_hdmi_stop_dma(dw);
+		break;
+
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	return ret;
+}
+
+static snd_pcm_uframes_t dw_hdmi_pointer(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_dw_hdmi *dw = substream->private_data;
+
+	return bytes_to_frames(runtime, dw->buf_offset);
+}
+
+static struct snd_pcm_ops snd_dw_hdmi_ops = {
+	.open = dw_hdmi_open,
+	.close = dw_hdmi_close,
+	.ioctl = snd_pcm_lib_ioctl,
+	.hw_params = dw_hdmi_hw_params,
+	.hw_free = dw_hdmi_hw_free,
+	.prepare = dw_hdmi_prepare,
+	.trigger = dw_hdmi_trigger,
+	.pointer = dw_hdmi_pointer,
+};
+
+int snd_dw_hdmi_probe(struct snd_dw_hdmi **dwp, struct device *dev,
+	void __iomem *base, int irq, struct imx_hdmi *hdmi)
+{
+	struct snd_dw_hdmi *dw;
+	struct snd_card *card;
+	struct snd_pcm *pcm;
+	unsigned revision;
+	int ret;
+
+	dw_hdmi_writeb(HDMI_IH_MUTE_AHBDMAAUD_STAT0_ALL,
+		       base + HDMI_IH_MUTE_AHBDMAAUD_STAT0);
+	revision = dw_hdmi_readb(base + HDMI_REVISION_ID);
+	if (revision != 0x0a && revision != 0x1a) {
+		dev_err(dev, "dw-hdmi-audio: unknown revision 0x%02x\n",
+			revision);
+		return -ENXIO;
+	}
+
+	ret = snd_card_create(SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1,
+			      THIS_MODULE, sizeof(struct snd_dw_hdmi), &card);
+	if (ret < 0)
+		return ret;
+
+	snd_card_set_dev(card, dev);
+
+	strlcpy(card->driver, DRIVER_NAME, sizeof(card->driver));
+	strlcpy(card->shortname, "DW-HDMI", sizeof(card->shortname));
+	snprintf(card->longname, sizeof(card->longname),
+		 "%s rev 0x%02x, irq %d", card->shortname, revision, irq);
+
+	dw = card->private_data;
+	dw->card = card;
+	dw->base = base;
+	dw->irq = irq;
+	dw->hdmi = hdmi;
+	dw->revision = revision;
+
+	ret = snd_pcm_new(card, "DW HDMI", 0, 1, 0, &pcm);
+	if (ret < 0)
+		goto err;
+
+	dw->pcm = pcm;
+	pcm->private_data = dw;
+	strlcpy(pcm->name, DRIVER_NAME, sizeof(pcm->name));
+	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_dw_hdmi_ops);
+
+	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
+			NULL, 0, 64 * 1024);
+
+	ret = snd_card_register(card);
+	if (ret < 0)
+		goto err;
+
+	*dwp = dw;
+
+	return 0;
+
+err:
+	snd_card_free(card);
+	return ret;
+}
+
+void snd_dw_hdmi_remove(struct snd_dw_hdmi *dw)
+{
+	snd_card_free(dw->card);
+}
diff --git a/drivers/staging/imx-drm/dw-hdmi-audio.h b/drivers/staging/imx-drm/dw-hdmi-audio.h
new file mode 100644
index 000000000000..82a709c9f612
--- /dev/null
+++ b/drivers/staging/imx-drm/dw-hdmi-audio.h
@@ -0,0 +1,13 @@
+#ifndef DW_HDMI_AUDIO_H
+#define DW_HDMI_AUDIO_H
+
+#include <linux/irqreturn.h>
+
+struct snd_dw_hdmi;
+struct imx_hdmi;
+
+int snd_dw_hdmi_probe(struct snd_dw_hdmi **dwp, struct device *,
+	void __iomem *, int, struct imx_hdmi *);
+void snd_dw_hdmi_remove(struct snd_dw_hdmi *dw);
+
+#endif
diff --git a/drivers/staging/imx-drm/imx-hdmi.c b/drivers/staging/imx-drm/imx-hdmi.c
index 097403a602d8..eb196c0862c8 100644
--- a/drivers/staging/imx-drm/imx-hdmi.c
+++ b/drivers/staging/imx-drm/imx-hdmi.c
@@ -27,6 +27,7 @@
 #include <drm/drm_edid.h>
 #include <drm/drm_encoder_slave.h>
 
+#include "dw-hdmi-audio.h"
 #include "ipu-v3/imx-ipu-v3.h"
 #include "imx-hdmi.h"
 #include "imx-drm.h"
@@ -119,6 +120,7 @@ struct imx_hdmi {
 	struct drm_connector connector;
 	struct drm_encoder encoder;
 
+	struct snd_dw_hdmi *audio;
 	enum imx_hdmi_devtype dev_type;
 	struct device *dev;
 	struct clk *isfr_clk;
@@ -366,6 +368,13 @@ static void hdmi_clk_regenerator_update_pixel_clock(struct imx_hdmi *hdmi)
 	hdmi_set_clk_regenerator(hdmi, hdmi->hdmi_data.video_mode.mpixelclock);
 }
 
+void imx_hdmi_set_sample_rate(struct imx_hdmi *hdmi, unsigned int rate)
+{
+	hdmi->sample_rate = rate;
+	hdmi_set_clk_regenerator(hdmi, hdmi->hdmi_data.video_mode.mpixelclock);
+}
+EXPORT_SYMBOL(imx_hdmi_set_sample_rate);
+
 /*
  * this submodule is responsible for the video data synchronization.
  * for example, for RGB 4:4:4 input, the data map is defined as
@@ -1705,10 +1714,20 @@ static int imx_hdmi_bind(struct device *dev, struct device *master, void *data)
 	/* Unmute interrupts */
 	hdmi_writeb(hdmi, ~HDMI_IH_PHY_STAT0_HPD, HDMI_IH_MUTE_PHY_STAT0);
 
+	ret = snd_dw_hdmi_probe(&hdmi->audio, dev, hdmi->regs, irq, hdmi);
+	if (ret)
+		goto err_audio;
+
 	dev_set_drvdata(dev, hdmi);
 
 	return 0;
 
+err_audio:
+	/* Disable all interrupts */
+	hdmi_writeb(hdmi, ~0, HDMI_IH_MUTE_PHY_STAT0);
+
+	hdmi->connector.funcs->destroy(&hdmi->connector);
+	hdmi->encoder.funcs->destroy(&hdmi->encoder);
 err_iahb:
 	clk_disable_unprepare(hdmi->iahb_clk);
 err_isfr:
@@ -1722,6 +1741,8 @@ static void imx_hdmi_unbind(struct device *dev, struct device *master,
 {
 	struct imx_hdmi *hdmi = dev_get_drvdata(dev);
 
+	snd_dw_hdmi_remove(hdmi->audio);
+
 	/* Disable all interrupts */
 	hdmi_writeb(hdmi, ~0, HDMI_IH_MUTE_PHY_STAT0);
 
diff --git a/drivers/staging/imx-drm/imx-hdmi.h b/drivers/staging/imx-drm/imx-hdmi.h
index 39b677689db6..8029febdbabe 100644
--- a/drivers/staging/imx-drm/imx-hdmi.h
+++ b/drivers/staging/imx-drm/imx-hdmi.h
@@ -1029,4 +1029,8 @@ enum {
 	HDMI_A_VIDPOLCFG_HSYNCPOL_ACTIVE_HIGH = 0x2,
 	HDMI_A_VIDPOLCFG_HSYNCPOL_ACTIVE_LOW = 0x0,
 };
+
+struct imx_hdmi;
+void imx_hdmi_set_sample_rate(struct imx_hdmi *hdmi, unsigned int rate);
+
 #endif /* __IMX_HDMI_H__ */
-- 
1.7.4.4