drm: bridge: dw-hdmi: Move the driver to a separate directory.

The driver is already made of 5 separate source files. Move it to a
newly created directory named synopsys where more Synopsys bridge
drivers can be added later (for the DisplayPort controller for
instance).

Suggested-by: Jose Abreu <Jose.Abreu@synopsys.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Jose Abreu <joabreu@synopsys.com>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20170303172007.26541-10-laurent.pinchart+renesas@ideasonboard.com

drivers/gpu/drm/bridge/synopsys/Kconfig

@@ -0,0 +1,23 @@
+config DRM_DW_HDMI
+	tristate
+	select DRM_KMS_HELPER
+
+config DRM_DW_HDMI_AHB_AUDIO
+	tristate "Synopsys Designware AHB Audio interface"
+	depends on DRM_DW_HDMI && SND
+	select SND_PCM
+	select SND_PCM_ELD
+	select SND_PCM_IEC958
+	help
+	  Support the AHB Audio interface which is part of the Synopsys
+	  Designware HDMI block.  This is used in conjunction with
+	  the i.MX6 HDMI driver.
+
+config DRM_DW_HDMI_I2S_AUDIO
+	tristate "Synopsys Designware I2S Audio interface"
+	depends on SND_SOC
+	depends on DRM_DW_HDMI
+	select SND_SOC_HDMI_CODEC
+	help
+	  Support the I2S Audio interface which is part of the Synopsys
+	  Designware HDMI block.

drivers/gpu/drm/bridge/synopsys/Makefile

@@ -0,0 +1,5 @@
+#ccflags-y := -Iinclude/drm
+
+obj-$(CONFIG_DRM_DW_HDMI) += dw-hdmi.o
+obj-$(CONFIG_DRM_DW_HDMI_AHB_AUDIO) += dw-hdmi-ahb-audio.o
+obj-$(CONFIG_DRM_DW_HDMI_I2S_AUDIO) += dw-hdmi-i2s-audio.o

drivers/gpu/drm/bridge/synopsys/dw-hdmi-ahb-audio.c

@@ -0,0 +1,652 @@
+/*
+ * 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 Designware HDMI Tx found in iMX6.
+ */
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <drm/bridge/dw_hdmi.h>
+#include <drm/drm_edid.h>
+
+#include <sound/asoundef.h>
+#include <sound/core.h>
+#include <sound/initval.h>
+#include <sound/pcm.h>
+#include <sound/pcm_drm_eld.h>
+#include <sound/pcm_iec958.h>
+
+#include "dw-hdmi-audio.h"
+
+#define DRIVER_NAME "dw-hdmi-ahb-audio"
+
+/* Provide some bits rather than bit offsets */
+enum {
+	HDMI_AHB_DMA_CONF0_SW_FIFO_RST = BIT(7),
+	HDMI_AHB_DMA_CONF0_EN_HLOCK = BIT(3),
+	HDMI_AHB_DMA_START_START = BIT(0),
+	HDMI_AHB_DMA_STOP_STOP = BIT(0),
+	HDMI_IH_MUTE_AHBDMAAUD_STAT0_ERROR = BIT(5),
+	HDMI_IH_MUTE_AHBDMAAUD_STAT0_LOST = BIT(4),
+	HDMI_IH_MUTE_AHBDMAAUD_STAT0_RETRY = BIT(3),
+	HDMI_IH_MUTE_AHBDMAAUD_STAT0_DONE = BIT(2),
+	HDMI_IH_MUTE_AHBDMAAUD_STAT0_BUFFFULL = BIT(1),
+	HDMI_IH_MUTE_AHBDMAAUD_STAT0_BUFFEMPTY = BIT(0),
+	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_ERROR = BIT(5),
+	HDMI_IH_AHBDMAAUD_STAT0_LOST = BIT(4),
+	HDMI_IH_AHBDMAAUD_STAT0_RETRY = BIT(3),
+	HDMI_IH_AHBDMAAUD_STAT0_DONE = BIT(2),
+	HDMI_IH_AHBDMAAUD_STAT0_BUFFFULL = BIT(1),
+	HDMI_IH_AHBDMAAUD_STAT0_BUFFEMPTY = BIT(0),
+	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,
+	HDMI_AHB_DMA_CONF0_INCR16 = 2 << 1,
+	HDMI_AHB_DMA_CONF0_INCR8 = 1 << 1,
+	HDMI_AHB_DMA_CONF0_INCR4 = 0,
+	HDMI_AHB_DMA_CONF0_BURST_MODE = BIT(0),
+	HDMI_AHB_DMA_MASK_DONE = BIT(7),
+
+	HDMI_REVISION_ID = 0x0001,
+	HDMI_IH_AHBDMAAUD_STAT0 = 0x0109,
+	HDMI_IH_MUTE_AHBDMAAUD_STAT0 = 0x0189,
+	HDMI_FC_AUDICONF2 = 0x1027,
+	HDMI_FC_AUDSCONF = 0x1063,
+	HDMI_FC_AUDSCONF_LAYOUT1 = 1 << 0,
+	HDMI_FC_AUDSCONF_LAYOUT0 = 0 << 0,
+	HDMI_AHB_DMA_CONF0 = 0x3600,
+	HDMI_AHB_DMA_START = 0x3601,
+	HDMI_AHB_DMA_STOP = 0x3602,
+	HDMI_AHB_DMA_THRSLD = 0x3603,
+	HDMI_AHB_DMA_STRADDR0 = 0x3604,
+	HDMI_AHB_DMA_STPADDR0 = 0x3608,
+	HDMI_AHB_DMA_MASK = 0x3614,
+	HDMI_AHB_DMA_POL = 0x3615,
+	HDMI_AHB_DMA_CONF1 = 0x3616,
+	HDMI_AHB_DMA_BUFFPOL = 0x361a,
+};
+
+struct dw_hdmi_channel_conf {
+	u8 conf1;
+	u8 ca;
+};
+
+/*
+ * The default mapping of ALSA channels to HDMI channels and speaker
+ * allocation bits.  Note that we can't do channel remapping here -
+ * channels must be in the same order.
+ *
+ * Mappings for alsa-lib pcm/surround*.conf files:
+ *
+ *		Front	Sur4.0	Sur4.1	Sur5.0	Sur5.1	Sur7.1
+ * Channels	2	4	6	6	6	8
+ *
+ * Our mapping from ALSA channel to CEA686D speaker name and HDMI channel:
+ *
+ *				Number of ALSA channels
+ * ALSA Channel	2	3	4	5	6	7	8
+ * 0		FL:0	=	=	=	=	=	=
+ * 1		FR:1	=	=	=	=	=	=
+ * 2			FC:3	RL:4	LFE:2	=	=	=
+ * 3				RR:5	RL:4	FC:3	=	=
+ * 4					RR:5	RL:4	=	=
+ * 5						RR:5	=	=
+ * 6							RC:6	=
+ * 7							RLC/FRC	RLC/FRC
+ */
+static struct dw_hdmi_channel_conf default_hdmi_channel_config[7] = {
+	{ 0x03, 0x00 },	/* FL,FR */
+	{ 0x0b, 0x02 },	/* FL,FR,FC */
+	{ 0x33, 0x08 },	/* FL,FR,RL,RR */
+	{ 0x37, 0x09 },	/* FL,FR,LFE,RL,RR */
+	{ 0x3f, 0x0b },	/* FL,FR,LFE,FC,RL,RR */
+	{ 0x7f, 0x0f },	/* FL,FR,LFE,FC,RL,RR,RC */
+	{ 0xff, 0x13 },	/* FL,FR,LFE,FC,RL,RR,[FR]RC,[FR]LC */
+};
+
+struct snd_dw_hdmi {
+	struct snd_card *card;
+	struct snd_pcm *pcm;
+	spinlock_t lock;
+	struct dw_hdmi_audio_data data;
+	struct snd_pcm_substream *substream;
+	void (*reformat)(struct snd_dw_hdmi *, size_t, size_t);
+	void *buf_src;
+	void *buf_dst;
+	dma_addr_t buf_addr;
+	unsigned buf_offset;
+	unsigned buf_period;
+	unsigned buf_size;
+	unsigned channels;
+	u8 revision;
+	u8 iec_offset;
+	u8 cs[192][8];
+};
+
+static void dw_hdmi_writel(u32 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)
+{
+	u32 *src = dw->buf_src + offset;
+	u32 *dst = dw->buf_dst + offset;
+	u32 *end = dw->buf_src + offset + bytes;
+
+	do {
+		u32 b, sample = *src++;
+
+		b = (sample & 8) << (28 - 3);
+
+		sample >>= 4;
+
+		*dst++ = sample | b;
+	} while (src < end);
+}
+
+static u32 parity(u32 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)
+{
+	u32 *src = dw->buf_src + offset;
+	u32 *dst = dw->buf_dst + offset;
+	u32 *end = dw->buf_src + offset + bytes;
+
+	do {
+		unsigned i;
+		u8 *cs;
+
+		cs = dw->cs[dw->iec_offset++];
+		if (dw->iec_offset >= 192)
+			dw->iec_offset = 0;
+
+		i = dw->channels;
+		do {
+			u32 sample = *src++;
+
+			sample &= ~0xff000000;
+			sample |= *cs++ << 24;
+			sample |= parity(sample & ~0xf8000000);
+
+			*dst++ = sample;
+		} while (--i);
+	} while (src < end);
+}
+
+static void dw_hdmi_create_cs(struct snd_dw_hdmi *dw,
+	struct snd_pcm_runtime *runtime)
+{
+	u8 cs[4];
+	unsigned ch, i, j;
+
+	snd_pcm_create_iec958_consumer(runtime, cs, sizeof(cs));
+
+	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)
+{
+	void __iomem *base = dw->data.base;
+	unsigned offset = dw->buf_offset;
+	unsigned period = dw->buf_period;
+	u32 start, stop;
+
+	dw->reformat(dw, offset, period);
+
+	/* Clear all irqs before enabling irqs and starting DMA */
+	writeb_relaxed(HDMI_IH_AHBDMAAUD_STAT0_ALL,
+		       base + HDMI_IH_AHBDMAAUD_STAT0);
+
+	start = dw->buf_addr + offset;
+	stop = start + period - 1;
+
+	/* Setup the hardware start/stop addresses */
+	dw_hdmi_writel(start, base + HDMI_AHB_DMA_STRADDR0);
+	dw_hdmi_writel(stop, base + HDMI_AHB_DMA_STPADDR0);
+
+	writeb_relaxed((u8)~HDMI_AHB_DMA_MASK_DONE, base + HDMI_AHB_DMA_MASK);
+	writeb(HDMI_AHB_DMA_START_START, base + HDMI_AHB_DMA_START);
+
+	offset += period;
+	if (offset >= dw->buf_size)
+		offset = 0;
+	dw->buf_offset = offset;
+}
+
+static void dw_hdmi_stop_dma(struct snd_dw_hdmi *dw)
+{
+	/* Disable interrupts before disabling DMA */
+	writeb_relaxed(~0, dw->data.base + HDMI_AHB_DMA_MASK);
+	writeb_relaxed(HDMI_AHB_DMA_STOP_STOP, dw->data.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 = readb_relaxed(dw->data.base + HDMI_IH_AHBDMAAUD_STAT0);
+	if (!stat)
+		return IRQ_NONE;
+
+	writeb_relaxed(stat, dw->data.base + HDMI_IH_AHBDMAAUD_STAT0);
+
+	substream = dw->substream;
+	if (stat & HDMI_IH_AHBDMAAUD_STAT0_DONE && substream) {
+		snd_pcm_period_elapsed(substream);
+
+		spin_lock(&dw->lock);
+		if (dw->substream)
+			dw_hdmi_start_dma(dw);
+		spin_unlock(&dw->lock);
+	}
+
+	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 = 1024 * 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;
+	void __iomem *base = dw->data.base;
+	int ret;
+
+	runtime->hw = dw_hdmi_hw;
+
+	ret = snd_pcm_hw_constraint_eld(runtime, dw->data.eld);
+	if (ret < 0)
+		return ret;
+
+	ret = snd_pcm_limit_hw_rates(runtime);
+	if (ret < 0)
+		return ret;
+
+	ret = snd_pcm_hw_constraint_integer(runtime,
+					    SNDRV_PCM_HW_PARAM_PERIODS);
+	if (ret < 0)
+		return ret;
+
+	/* Limit the buffer size to the size of the preallocated buffer */
+	ret = snd_pcm_hw_constraint_minmax(runtime,
+					   SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
+					   0, substream->dma_buffer.bytes);
+	if (ret < 0)
+		return ret;
+
+	/* Clear FIFO */
+	writeb_relaxed(HDMI_AHB_DMA_CONF0_SW_FIFO_RST,
+		       base + HDMI_AHB_DMA_CONF0);
+
+	/* Configure interrupt polarities */
+	writeb_relaxed(~0, base + HDMI_AHB_DMA_POL);
+	writeb_relaxed(~0, base + HDMI_AHB_DMA_BUFFPOL);
+
+	/* Keep interrupts masked, and clear any pending */
+	writeb_relaxed(~0, base + HDMI_AHB_DMA_MASK);
+	writeb_relaxed(~0, base + HDMI_IH_AHBDMAAUD_STAT0);
+
+	ret = request_irq(dw->data.irq, snd_dw_hdmi_irq, IRQF_SHARED,
+			  "dw-hdmi-audio", dw);
+	if (ret)
+		return ret;
+
+	/* Un-mute done interrupt */
+	writeb_relaxed(HDMI_IH_MUTE_AHBDMAAUD_STAT0_ALL &
+		       ~HDMI_IH_MUTE_AHBDMAAUD_STAT0_DONE,
+		       base + HDMI_IH_MUTE_AHBDMAAUD_STAT0);
+
+	return 0;
+}
+
+static int dw_hdmi_close(struct snd_pcm_substream *substream)
+{
+	struct snd_dw_hdmi *dw = substream->private_data;
+
+	/* Mute all interrupts */
+	writeb_relaxed(HDMI_IH_MUTE_AHBDMAAUD_STAT0_ALL,
+		       dw->data.base + HDMI_IH_MUTE_AHBDMAAUD_STAT0);
+
+	free_irq(dw->data.irq, dw);
+
+	return 0;
+}
+
+static int dw_hdmi_hw_free(struct snd_pcm_substream *substream)
+{
+	return snd_pcm_lib_free_vmalloc_buffer(substream);
+}
+
+static int dw_hdmi_hw_params(struct snd_pcm_substream *substream,
+	struct snd_pcm_hw_params *params)
+{
+	/* Allocate the PCM runtime buffer, which is exposed to userspace. */
+	return snd_pcm_lib_alloc_vmalloc_buffer(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;
+	u8 threshold, conf0, conf1, layout, ca;
+
+	/* 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;
+	}
+
+	dw_hdmi_set_sample_rate(dw->data.hdmi, runtime->rate);
+
+	/* Minimum number of bytes in the fifo. */
+	runtime->hw.fifo_size = threshold * 32;
+
+	conf0 |= HDMI_AHB_DMA_CONF0_EN_HLOCK;
+	conf1 = default_hdmi_channel_config[runtime->channels - 2].conf1;
+	ca = default_hdmi_channel_config[runtime->channels - 2].ca;
+
+	/*
+	 * For >2 channel PCM audio, we need to select layout 1
+	 * and set an appropriate channel map.
+	 */
+	if (runtime->channels > 2)
+		layout = HDMI_FC_AUDSCONF_LAYOUT1;
+	else
+		layout = HDMI_FC_AUDSCONF_LAYOUT0;
+
+	writeb_relaxed(threshold, dw->data.base + HDMI_AHB_DMA_THRSLD);
+	writeb_relaxed(conf0, dw->data.base + HDMI_AHB_DMA_CONF0);
+	writeb_relaxed(conf1, dw->data.base + HDMI_AHB_DMA_CONF1);
+	writeb_relaxed(layout, dw->data.base + HDMI_FC_AUDSCONF);
+	writeb_relaxed(ca, dw->data.base + HDMI_FC_AUDICONF2);
+
+	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_src  = runtime->dma_area;
+	dw->buf_dst  = substream->dma_buffer.area;
+	dw->buf_addr = substream->dma_buffer.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;
+	unsigned long flags;
+	int ret = 0;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+		spin_lock_irqsave(&dw->lock, flags);
+		dw->buf_offset = 0;
+		dw->substream = substream;
+		dw_hdmi_start_dma(dw);
+		dw_hdmi_audio_enable(dw->data.hdmi);
+		spin_unlock_irqrestore(&dw->lock, flags);
+		substream->runtime->delay = substream->runtime->period_size;
+		break;
+
+	case SNDRV_PCM_TRIGGER_STOP:
+		spin_lock_irqsave(&dw->lock, flags);
+		dw->substream = NULL;
+		dw_hdmi_stop_dma(dw);
+		dw_hdmi_audio_disable(dw->data.hdmi);
+		spin_unlock_irqrestore(&dw->lock, flags);
+		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;
+
+	/*
+	 * We are unable to report the exact hardware position as
+	 * reading the 32-bit DMA position using 8-bit reads is racy.
+	 */
+	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,
+	.page = snd_pcm_lib_get_vmalloc_page,
+};
+
+static int snd_dw_hdmi_probe(struct platform_device *pdev)
+{
+	const struct dw_hdmi_audio_data *data = pdev->dev.platform_data;
+	struct device *dev = pdev->dev.parent;
+	struct snd_dw_hdmi *dw;
+	struct snd_card *card;
+	struct snd_pcm *pcm;
+	unsigned revision;
+	int ret;
+
+	writeb_relaxed(HDMI_IH_MUTE_AHBDMAAUD_STAT0_ALL,
+		       data->base + HDMI_IH_MUTE_AHBDMAAUD_STAT0);
+	revision = readb_relaxed(data->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_new(dev, SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1,
+			      THIS_MODULE, sizeof(struct snd_dw_hdmi), &card);
+	if (ret < 0)
+		return ret;
+
+	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,
+		 data->irq);
+
+	dw = card->private_data;
+	dw->card = card;
+	dw->data = *data;
+	dw->revision = revision;
+
+	spin_lock_init(&dw->lock);
+
+	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);
+
+	/*
+	 * To support 8-channel 96kHz audio reliably, we need 512k
+	 * to satisfy alsa with our restricted period (ERR004323).
+	 */
+	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
+			dev, 128 * 1024, 1024 * 1024);
+
+	ret = snd_card_register(card);
+	if (ret < 0)
+		goto err;
+
+	platform_set_drvdata(pdev, dw);
+
+	return 0;
+
+err:
+	snd_card_free(card);
+	return ret;
+}
+
+static int snd_dw_hdmi_remove(struct platform_device *pdev)
+{
+	struct snd_dw_hdmi *dw = platform_get_drvdata(pdev);
+
+	snd_card_free(dw->card);
+
+	return 0;
+}
+
+#if defined(CONFIG_PM_SLEEP) && defined(IS_NOT_BROKEN)
+/*
+ * This code is fine, but requires implementation in the dw_hdmi_trigger()
+ * method which is currently missing as I have no way to test this.
+ */
+static int snd_dw_hdmi_suspend(struct device *dev)
+{
+	struct snd_dw_hdmi *dw = dev_get_drvdata(dev);
+
+	snd_power_change_state(dw->card, SNDRV_CTL_POWER_D3cold);
+	snd_pcm_suspend_all(dw->pcm);
+
+	return 0;
+}
+
+static int snd_dw_hdmi_resume(struct device *dev)
+{
+	struct snd_dw_hdmi *dw = dev_get_drvdata(dev);
+
+	snd_power_change_state(dw->card, SNDRV_CTL_POWER_D0);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(snd_dw_hdmi_pm, snd_dw_hdmi_suspend,
+			 snd_dw_hdmi_resume);
+#define PM_OPS &snd_dw_hdmi_pm
+#else
+#define PM_OPS NULL
+#endif
+
+static struct platform_driver snd_dw_hdmi_driver = {
+	.probe	= snd_dw_hdmi_probe,
+	.remove	= snd_dw_hdmi_remove,
+	.driver	= {
+		.name = DRIVER_NAME,
+		.pm = PM_OPS,
+	},
+};
+
+module_platform_driver(snd_dw_hdmi_driver);
+
+MODULE_AUTHOR("Russell King <rmk+kernel@arm.linux.org.uk>");
+MODULE_DESCRIPTION("Synopsis Designware HDMI AHB ALSA interface");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRIVER_NAME);

drivers/gpu/drm/bridge/synopsys/dw-hdmi-audio.h

@@ -0,0 +1,21 @@
+#ifndef DW_HDMI_AUDIO_H
+#define DW_HDMI_AUDIO_H
+
+struct dw_hdmi;
+
+struct dw_hdmi_audio_data {
+	phys_addr_t phys;
+	void __iomem *base;
+	int irq;
+	struct dw_hdmi *hdmi;
+	u8 *eld;
+};
+
+struct dw_hdmi_i2s_audio_data {
+	struct dw_hdmi *hdmi;
+
+	void (*write)(struct dw_hdmi *hdmi, u8 val, int offset);
+	u8 (*read)(struct dw_hdmi *hdmi, int offset);
+};
+
+#endif

drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c

@@ -0,0 +1,141 @@
+/*
+ * dw-hdmi-i2s-audio.c
+ *
+ * Copyright (c) 2016 Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
+ *
+ * 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.
+ */
+#include <drm/bridge/dw_hdmi.h>
+
+#include <sound/hdmi-codec.h>
+
+#include "dw-hdmi.h"
+#include "dw-hdmi-audio.h"
+
+#define DRIVER_NAME "dw-hdmi-i2s-audio"
+
+static inline void hdmi_write(struct dw_hdmi_i2s_audio_data *audio,
+			      u8 val, int offset)
+{
+	struct dw_hdmi *hdmi = audio->hdmi;
+
+	audio->write(hdmi, val, offset);
+}
+
+static inline u8 hdmi_read(struct dw_hdmi_i2s_audio_data *audio, int offset)
+{
+	struct dw_hdmi *hdmi = audio->hdmi;
+
+	return audio->read(hdmi, offset);
+}
+
+static int dw_hdmi_i2s_hw_params(struct device *dev, void *data,
+				 struct hdmi_codec_daifmt *fmt,
+				 struct hdmi_codec_params *hparms)
+{
+	struct dw_hdmi_i2s_audio_data *audio = data;
+	struct dw_hdmi *hdmi = audio->hdmi;
+	u8 conf0 = 0;
+	u8 conf1 = 0;
+	u8 inputclkfs = 0;
+
+	/* it cares I2S only */
+	if ((fmt->fmt != HDMI_I2S) ||
+	    (fmt->bit_clk_master | fmt->frame_clk_master)) {
+		dev_err(dev, "unsupported format/settings\n");
+		return -EINVAL;
+	}
+
+	inputclkfs	= HDMI_AUD_INPUTCLKFS_64FS;
+	conf0		= HDMI_AUD_CONF0_I2S_ALL_ENABLE;
+
+	switch (hparms->sample_width) {
+	case 16:
+		conf1 = HDMI_AUD_CONF1_WIDTH_16;
+		break;
+	case 24:
+	case 32:
+		conf1 = HDMI_AUD_CONF1_WIDTH_24;
+		break;
+	}
+
+	dw_hdmi_set_sample_rate(hdmi, hparms->sample_rate);
+
+	hdmi_write(audio, inputclkfs, HDMI_AUD_INPUTCLKFS);
+	hdmi_write(audio, conf0, HDMI_AUD_CONF0);
+	hdmi_write(audio, conf1, HDMI_AUD_CONF1);
+
+	dw_hdmi_audio_enable(hdmi);
+
+	return 0;
+}
+
+static void dw_hdmi_i2s_audio_shutdown(struct device *dev, void *data)
+{
+	struct dw_hdmi_i2s_audio_data *audio = data;
+	struct dw_hdmi *hdmi = audio->hdmi;
+
+	dw_hdmi_audio_disable(hdmi);
+
+	hdmi_write(audio, HDMI_AUD_CONF0_SW_RESET, HDMI_AUD_CONF0);
+}
+
+static struct hdmi_codec_ops dw_hdmi_i2s_ops = {
+	.hw_params	= dw_hdmi_i2s_hw_params,
+	.audio_shutdown	= dw_hdmi_i2s_audio_shutdown,
+};
+
+static int snd_dw_hdmi_probe(struct platform_device *pdev)
+{
+	struct dw_hdmi_i2s_audio_data *audio = pdev->dev.platform_data;
+	struct platform_device_info pdevinfo;
+	struct hdmi_codec_pdata pdata;
+	struct platform_device *platform;
+
+	pdata.ops		= &dw_hdmi_i2s_ops;
+	pdata.i2s		= 1;
+	pdata.max_i2s_channels	= 6;
+	pdata.data		= audio;
+
+	memset(&pdevinfo, 0, sizeof(pdevinfo));
+	pdevinfo.parent		= pdev->dev.parent;
+	pdevinfo.id		= PLATFORM_DEVID_AUTO;
+	pdevinfo.name		= HDMI_CODEC_DRV_NAME;
+	pdevinfo.data		= &pdata;
+	pdevinfo.size_data	= sizeof(pdata);
+	pdevinfo.dma_mask	= DMA_BIT_MASK(32);
+
+	platform = platform_device_register_full(&pdevinfo);
+	if (IS_ERR(platform))
+		return PTR_ERR(platform);
+
+	dev_set_drvdata(&pdev->dev, platform);
+
+	return 0;
+}
+
+static int snd_dw_hdmi_remove(struct platform_device *pdev)
+{
+	struct platform_device *platform = dev_get_drvdata(&pdev->dev);
+
+	platform_device_unregister(platform);
+
+	return 0;
+}
+
+static struct platform_driver snd_dw_hdmi_driver = {
+	.probe	= snd_dw_hdmi_probe,
+	.remove	= snd_dw_hdmi_remove,
+	.driver	= {
+		.name = DRIVER_NAME,
+		.owner = THIS_MODULE,
+	},
+};
+module_platform_driver(snd_dw_hdmi_driver);
+
+MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>");
+MODULE_DESCRIPTION("Synopsis Designware HDMI I2S ALSA SoC interface");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRIVER_NAME);