[PATCH v2 2/3] drm/vc4: Add HDMI audio support

From: Eric Anholt
Date: Mon Feb 27 2017 - 15:29:35 EST

The HDMI encoder IP embeds all needed blocks to output audio, with a
custom DAI called MAI moving audio between the two parts of the HDMI
core. This driver now exposes a sound card to let users stream audio
to their display.

Using the hdmi-codec driver has been considered here, but MAI meant
having to significantly rework hdmi-codec, and it would have left
little shared code with the I2S mode anyway.

The encoder requires that the audio be SPDIF-formatted frames only,
which alsalib will format-convert for us.

This patch is the combined work of Eric Anholt (initial register setup
with a separate dmaengine driver and using simple-audio-card) and
Boris Brezillon (moving it all into HDMI, massive debug to get it
actually working), and which Eric has the permission to release.

v2: Drop "-audio" from sound card name, since that's already implied
(suggestion by Boris)

Signed-off-by: Eric Anholt <eric@xxxxxxxxxx>
---
drivers/gpu/drm/vc4/Kconfig | 4 +
drivers/gpu/drm/vc4/vc4_hdmi.c | 494 ++++++++++++++++++++++++++++++++++++++++-
drivers/gpu/drm/vc4/vc4_regs.h | 107 ++++++++-
3 files changed, 603 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/vc4/Kconfig b/drivers/gpu/drm/vc4/Kconfig
index e1517d07cb7d..973b4203c0b2 100644
--- a/drivers/gpu/drm/vc4/Kconfig
+++ b/drivers/gpu/drm/vc4/Kconfig
@@ -2,11 +2,15 @@ config DRM_VC4
tristate "Broadcom VC4 Graphics"
depends on ARCH_BCM2835 || COMPILE_TEST
depends on DRM
+ depends on SND && SND_SOC
depends on COMMON_CLK
select DRM_KMS_HELPER
select DRM_KMS_CMA_HELPER
select DRM_GEM_CMA_HELPER
select DRM_PANEL
+ select SND_PCM
+ select SND_PCM_ELD
+ select SND_SOC_GENERIC_DMAENGINE_PCM
select DRM_MIPI_DSI
help
Choose this option if you have a system that has a Broadcom
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 93d5994f3a04..e4abf4bfc464 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -31,11 +31,27 @@
#include "linux/clk.h"
#include "linux/component.h"
#include "linux/i2c.h"
+#include "linux/of_address.h"
#include "linux/of_gpio.h"
#include "linux/of_platform.h"
+#include "linux/rational.h"
+#include "sound/dmaengine_pcm.h"
+#include "sound/pcm_drm_eld.h"
+#include "sound/pcm_params.h"
+#include "sound/soc.h"
#include "vc4_drv.h"
#include "vc4_regs.h"

+/* HDMI audio information */
+struct vc4_hdmi_audio {
+ struct snd_soc_card card;
+ struct snd_soc_dai_link link;
+ int samplerate;
+ int channels;
+ struct snd_dmaengine_dai_dma_data dma_data;
+ struct snd_pcm_substream *substream;
+};
+
/* General HDMI hardware state. */
struct vc4_hdmi {
struct platform_device *pdev;
@@ -43,6 +59,8 @@ struct vc4_hdmi {
struct drm_encoder *encoder;
struct drm_connector *connector;

+ struct vc4_hdmi_audio audio;
+
struct i2c_adapter *ddc;
void __iomem *hdmicore_regs;
void __iomem *hd_regs;
@@ -98,6 +116,10 @@ static const struct {
HDMI_REG(VC4_HDMI_SW_RESET_CONTROL),
HDMI_REG(VC4_HDMI_HOTPLUG_INT),
HDMI_REG(VC4_HDMI_HOTPLUG),
+ HDMI_REG(VC4_HDMI_MAI_CHANNEL_MAP),
+ HDMI_REG(VC4_HDMI_MAI_CONFIG),
+ HDMI_REG(VC4_HDMI_MAI_FORMAT),
+ HDMI_REG(VC4_HDMI_AUDIO_PACKET_CONFIG),
HDMI_REG(VC4_HDMI_RAM_PACKET_CONFIG),
HDMI_REG(VC4_HDMI_HORZA),
HDMI_REG(VC4_HDMI_HORZB),
@@ -108,6 +130,7 @@ static const struct {
HDMI_REG(VC4_HDMI_VERTB0),
HDMI_REG(VC4_HDMI_VERTB1),
HDMI_REG(VC4_HDMI_TX_PHY_RESET_CTL),
+ HDMI_REG(VC4_HDMI_TX_PHY_CTL0),
};

static const struct {
@@ -116,6 +139,9 @@ static const struct {
} hd_regs[] = {
HDMI_REG(VC4_HD_M_CTL),
HDMI_REG(VC4_HD_MAI_CTL),
+ HDMI_REG(VC4_HD_MAI_THR),
+ HDMI_REG(VC4_HD_MAI_FMT),
+ HDMI_REG(VC4_HD_MAI_SMP),
HDMI_REG(VC4_HD_VID_CTL),
HDMI_REG(VC4_HD_CSC_CTL),
HDMI_REG(VC4_HD_FRAME_COUNT),
@@ -215,6 +241,7 @@ static int vc4_hdmi_connector_get_modes(struct drm_connector *connector)

drm_mode_connector_update_edid_property(connector, edid);
ret = drm_add_edid_modes(connector, edid);
+ drm_edid_to_eld(connector, edid);

return ret;
}
@@ -300,7 +327,7 @@ static void vc4_hdmi_write_infoframe(struct drm_encoder *encoder,
struct drm_device *dev = encoder->dev;
struct vc4_dev *vc4 = to_vc4_dev(dev);
u32 packet_id = frame->any.type - 0x80;
- u32 packet_reg = VC4_HDMI_GCP_0 + VC4_HDMI_PACKET_STRIDE * packet_id;
+ u32 packet_reg = VC4_HDMI_RAM_PACKET(packet_id);
uint8_t buffer[VC4_HDMI_PACKET_STRIDE];
ssize_t len, i;
int ret;
@@ -381,6 +408,24 @@ static void vc4_hdmi_set_spd_infoframe(struct drm_encoder *encoder)
vc4_hdmi_write_infoframe(encoder, &frame);
}

+static void vc4_hdmi_set_audio_infoframe(struct drm_encoder *encoder)
+{
+ struct drm_device *drm = encoder->dev;
+ struct vc4_dev *vc4 = drm->dev_private;
+ struct vc4_hdmi *hdmi = vc4->hdmi;
+ union hdmi_infoframe frame;
+ int ret;
+
+ ret = hdmi_audio_infoframe_init(&frame.audio);
+
+ frame.audio.coding_type = HDMI_AUDIO_CODING_TYPE_STREAM;
+ frame.audio.sample_frequency = HDMI_AUDIO_SAMPLE_FREQUENCY_STREAM;
+ frame.audio.sample_size = HDMI_AUDIO_SAMPLE_SIZE_STREAM;
+ frame.audio.channels = hdmi->audio.channels;
+
+ vc4_hdmi_write_infoframe(encoder, &frame);
+}
+
static void vc4_hdmi_set_infoframes(struct drm_encoder *encoder)
{
vc4_hdmi_set_avi_infoframe(encoder);
@@ -589,6 +634,447 @@ static const struct drm_encoder_helper_funcs vc4_hdmi_encoder_helper_funcs = {
.enable = vc4_hdmi_encoder_enable,
};

+/* HDMI audio codec callbacks */
+static void vc4_hdmi_audio_set_mai_clock(struct vc4_hdmi *hdmi)
+{
+ struct drm_device *drm = hdmi->encoder->dev;
+ struct vc4_dev *vc4 = to_vc4_dev(drm);
+ u32 hsm_clock = clk_get_rate(hdmi->hsm_clock);
+ unsigned long n, m;
+
+ rational_best_approximation(hsm_clock, hdmi->audio.samplerate,
+ VC4_HD_MAI_SMP_N_MASK >>
+ VC4_HD_MAI_SMP_N_SHIFT,
+ (VC4_HD_MAI_SMP_M_MASK >>
+ VC4_HD_MAI_SMP_M_SHIFT) + 1,
+ &n, &m);
+
+ HD_WRITE(VC4_HD_MAI_SMP,
+ VC4_SET_FIELD(n, VC4_HD_MAI_SMP_N) |
+ VC4_SET_FIELD(m - 1, VC4_HD_MAI_SMP_M));
+}
+
+static void vc4_hdmi_set_n_cts(struct vc4_hdmi *hdmi)
+{
+ struct drm_encoder *encoder = hdmi->encoder;
+ struct drm_crtc *crtc = encoder->crtc;
+ struct drm_device *drm = encoder->dev;
+ struct vc4_dev *vc4 = to_vc4_dev(drm);
+ const struct drm_display_mode *mode = &crtc->state->adjusted_mode;
+ u32 samplerate = hdmi->audio.samplerate;
+ u32 n, cts;
+ u64 tmp;
+
+ n = 128 * samplerate / 1000;
+ tmp = (u64)(mode->clock * 1000) * n;
+ do_div(tmp, 128 * samplerate);
+ cts = tmp;
+
+ HDMI_WRITE(VC4_HDMI_CRP_CFG,
+ VC4_HDMI_CRP_CFG_EXTERNAL_CTS_EN |
+ VC4_SET_FIELD(n, VC4_HDMI_CRP_CFG_N));
+
+ /*
+ * We could get slightly more accurate clocks in some cases by
+ * providing a CTS_1 value. The two CTS values are alternated
+ * between based on the period fields
+ */
+ HDMI_WRITE(VC4_HDMI_CTS_0, cts);
+ HDMI_WRITE(VC4_HDMI_CTS_1, cts);
+}
+
+static inline struct vc4_hdmi *dai_to_hdmi(struct snd_soc_dai *dai)
+{
+ struct snd_soc_card *card = snd_soc_dai_get_drvdata(dai);
+
+ return snd_soc_card_get_drvdata(card);
+}
+
+static int vc4_hdmi_audio_startup(struct snd_pcm_substream *substream,
+ struct snd_soc_dai *dai)
+{
+ struct vc4_hdmi *hdmi = dai_to_hdmi(dai);
+ struct drm_encoder *encoder = hdmi->encoder;
+ struct vc4_dev *vc4 = to_vc4_dev(encoder->dev);
+ int ret;
+
+ if (hdmi->audio.substream && hdmi->audio.substream != substream)
+ return -EINVAL;
+
+ hdmi->audio.substream = substream;
+
+ /*
+ * If the HDMI encoder hasn't probed, or the encoder is
+ * currently in DVI mode, treat the codec dai as missing.
+ */
+ if (!encoder->crtc || !(HDMI_READ(VC4_HDMI_RAM_PACKET_CONFIG) &
+ VC4_HDMI_RAM_PACKET_ENABLE))
+ return -ENODEV;
+
+ ret = snd_pcm_hw_constraint_eld(substream->runtime,
+ hdmi->connector->eld);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int vc4_hdmi_audio_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
+{
+ return 0;
+}
+
+static void vc4_hdmi_audio_reset(struct vc4_hdmi *hdmi)
+{
+ struct drm_encoder *encoder = hdmi->encoder;
+ struct drm_device *drm = encoder->dev;
+ struct device *dev = &hdmi->pdev->dev;
+ struct vc4_dev *vc4 = to_vc4_dev(drm);
+ int ret;
+
+ ret = vc4_hdmi_stop_packet(encoder, HDMI_INFOFRAME_TYPE_AUDIO);
+ if (ret)
+ dev_err(dev, "Failed to stop audio infoframe: %d\n", ret);
+
+ HD_WRITE(VC4_HD_MAI_CTL, VC4_HD_MAI_CTL_RESET);
+ HD_WRITE(VC4_HD_MAI_CTL, VC4_HD_MAI_CTL_ERRORF);
+ HD_WRITE(VC4_HD_MAI_CTL, VC4_HD_MAI_CTL_FLUSH);
+}
+
+static void vc4_hdmi_audio_shutdown(struct snd_pcm_substream *substream,
+ struct snd_soc_dai *dai)
+{
+ struct vc4_hdmi *hdmi = dai_to_hdmi(dai);
+
+ if (substream != hdmi->audio.substream)
+ return;
+
+ vc4_hdmi_audio_reset(hdmi);
+
+ hdmi->audio.substream = NULL;
+}
+
+/* HDMI audio codec callbacks */
+static int vc4_hdmi_audio_hw_params(struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params,
+ struct snd_soc_dai *dai)
+{
+ struct vc4_hdmi *hdmi = dai_to_hdmi(dai);
+ struct drm_encoder *encoder = hdmi->encoder;
+ struct drm_device *drm = encoder->dev;
+ struct device *dev = &hdmi->pdev->dev;
+ struct vc4_dev *vc4 = to_vc4_dev(drm);
+ u32 audio_packet_config, channel_mask;
+ u32 channel_map, i;
+
+ if (substream != hdmi->audio.substream)
+ return -EINVAL;
+
+ dev_dbg(dev, "%s: %u Hz, %d bit, %d channels\n", __func__,
+ params_rate(params), params_width(params),
+ params_channels(params));
+
+ hdmi->audio.channels = params_channels(params);
+ hdmi->audio.samplerate = params_rate(params);
+
+ HD_WRITE(VC4_HD_MAI_CTL,
+ VC4_HD_MAI_CTL_RESET |
+ VC4_HD_MAI_CTL_FLUSH |
+ VC4_HD_MAI_CTL_DLATE |
+ VC4_HD_MAI_CTL_ERRORE |
+ VC4_HD_MAI_CTL_ERRORF);
+
+ vc4_hdmi_audio_set_mai_clock(hdmi);
+
+ audio_packet_config =
+ VC4_HDMI_AUDIO_PACKET_ZERO_DATA_ON_SAMPLE_FLAT |
+ VC4_HDMI_AUDIO_PACKET_ZERO_DATA_ON_INACTIVE_CHANNELS |
+ VC4_SET_FIELD(0xf, VC4_HDMI_AUDIO_PACKET_B_FRAME_IDENTIFIER);
+
+ channel_mask = GENMASK(hdmi->audio.channels - 1, 0);
+ audio_packet_config |= VC4_SET_FIELD(channel_mask,
+ VC4_HDMI_AUDIO_PACKET_CEA_MASK);
+
+ /* Set the MAI threshold. This logic mimics the firmware's. */
+ if (hdmi->audio.samplerate > 96000) {
+ HD_WRITE(VC4_HD_MAI_THR,
+ VC4_SET_FIELD(0x12, VC4_HD_MAI_THR_DREQHIGH) |
+ VC4_SET_FIELD(0x12, VC4_HD_MAI_THR_DREQLOW));
+ } else if (hdmi->audio.samplerate > 48000) {
+ HD_WRITE(VC4_HD_MAI_THR,
+ VC4_SET_FIELD(0x14, VC4_HD_MAI_THR_DREQHIGH) |
+ VC4_SET_FIELD(0x12, VC4_HD_MAI_THR_DREQLOW));
+ } else {
+ HD_WRITE(VC4_HD_MAI_THR,
+ VC4_SET_FIELD(0x10, VC4_HD_MAI_THR_PANICHIGH) |
+ VC4_SET_FIELD(0x10, VC4_HD_MAI_THR_PANICLOW) |
+ VC4_SET_FIELD(0x10, VC4_HD_MAI_THR_DREQHIGH) |
+ VC4_SET_FIELD(0x10, VC4_HD_MAI_THR_DREQLOW));
+ }
+
+ HDMI_WRITE(VC4_HDMI_MAI_CONFIG,
+ VC4_HDMI_MAI_CONFIG_BIT_REVERSE |
+ VC4_SET_FIELD(channel_mask, VC4_HDMI_MAI_CHANNEL_MASK));
+
+ channel_map = 0;
+ for (i = 0; i < 8; i++) {
+ if (channel_mask & BIT(i))
+ channel_map |= i << (3 * i);
+ }
+
+ HDMI_WRITE(VC4_HDMI_MAI_CHANNEL_MAP, channel_map);
+ HDMI_WRITE(VC4_HDMI_AUDIO_PACKET_CONFIG, audio_packet_config);
+ vc4_hdmi_set_n_cts(hdmi);
+
+ return 0;
+}
+
+static int vc4_hdmi_audio_trigger(struct snd_pcm_substream *substream, int cmd,
+ struct snd_soc_dai *dai)
+{
+ struct vc4_hdmi *hdmi = dai_to_hdmi(dai);
+ struct drm_encoder *encoder = hdmi->encoder;
+ struct drm_device *drm = encoder->dev;
+ struct vc4_dev *vc4 = to_vc4_dev(drm);
+
+ switch (cmd) {
+ case SNDRV_PCM_TRIGGER_START:
+ vc4_hdmi_set_audio_infoframe(encoder);
+ HDMI_WRITE(VC4_HDMI_TX_PHY_CTL0,
+ HDMI_READ(VC4_HDMI_TX_PHY_CTL0) &
+ ~VC4_HDMI_TX_PHY_RNG_PWRDN);
+ HD_WRITE(VC4_HD_MAI_CTL,
+ VC4_SET_FIELD(hdmi->audio.channels,
+ VC4_HD_MAI_CTL_CHNUM) |
+ VC4_HD_MAI_CTL_ENABLE);
+ break;
+ case SNDRV_PCM_TRIGGER_STOP:
+ HD_WRITE(VC4_HD_MAI_CTL,
+ VC4_HD_MAI_CTL_DLATE |
+ VC4_HD_MAI_CTL_ERRORE |
+ VC4_HD_MAI_CTL_ERRORF);
+ HDMI_WRITE(VC4_HDMI_TX_PHY_CTL0,
+ HDMI_READ(VC4_HDMI_TX_PHY_CTL0) |
+ VC4_HDMI_TX_PHY_RNG_PWRDN);
+ break;
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+static inline struct vc4_hdmi *
+snd_component_to_hdmi(struct snd_soc_component *component)
+{
+ struct snd_soc_card *card = snd_soc_component_get_drvdata(component);
+
+ return snd_soc_card_get_drvdata(card);
+}
+
+static int vc4_hdmi_audio_eld_ctl_info(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_info *uinfo)
+{
+ struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
+ struct vc4_hdmi *hdmi = snd_component_to_hdmi(component);
+
+ uinfo->type = SNDRV_CTL_ELEM_TYPE_BYTES;
+ uinfo->count = sizeof(hdmi->connector->eld);
+
+ return 0;
+}
+
+static int vc4_hdmi_audio_eld_ctl_get(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *ucontrol)
+{
+ struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
+ struct vc4_hdmi *hdmi = snd_component_to_hdmi(component);
+
+ memcpy(ucontrol->value.bytes.data, hdmi->connector->eld,
+ sizeof(hdmi->connector->eld));
+
+ return 0;
+}
+
+static const struct snd_kcontrol_new vc4_hdmi_audio_controls[] = {
+ {
+ .access = SNDRV_CTL_ELEM_ACCESS_READ |
+ SNDRV_CTL_ELEM_ACCESS_VOLATILE,
+ .iface = SNDRV_CTL_ELEM_IFACE_PCM,
+ .name = "ELD",
+ .info = vc4_hdmi_audio_eld_ctl_info,
+ .get = vc4_hdmi_audio_eld_ctl_get,
+ },
+};
+
+static const struct snd_soc_dapm_widget vc4_hdmi_audio_widgets[] = {
+ SND_SOC_DAPM_OUTPUT("TX"),
+};
+
+static const struct snd_soc_dapm_route vc4_hdmi_audio_routes[] = {
+ { "TX", NULL, "Playback" },
+};
+
+static const struct snd_soc_codec_driver vc4_hdmi_audio_codec_drv = {
+ .component_driver = {
+ .controls = vc4_hdmi_audio_controls,
+ .num_controls = ARRAY_SIZE(vc4_hdmi_audio_controls),
+ .dapm_widgets = vc4_hdmi_audio_widgets,
+ .num_dapm_widgets = ARRAY_SIZE(vc4_hdmi_audio_widgets),
+ .dapm_routes = vc4_hdmi_audio_routes,
+ .num_dapm_routes = ARRAY_SIZE(vc4_hdmi_audio_routes),
+ },
+};
+
+static const struct snd_soc_dai_ops vc4_hdmi_audio_dai_ops = {
+ .startup = vc4_hdmi_audio_startup,
+ .shutdown = vc4_hdmi_audio_shutdown,
+ .hw_params = vc4_hdmi_audio_hw_params,
+ .set_fmt = vc4_hdmi_audio_set_fmt,
+ .trigger = vc4_hdmi_audio_trigger,
+};
+
+static struct snd_soc_dai_driver vc4_hdmi_audio_codec_dai_drv = {
+ .name = "vc4-hdmi-hifi",
+ .playback = {
+ .stream_name = "Playback",
+ .channels_min = 2,
+ .channels_max = 8,
+ .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,
+ .formats = SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_LE,
+ },
+};
+
+static const struct snd_soc_component_driver vc4_hdmi_audio_cpu_dai_comp = {
+ .name = "vc4-hdmi-cpu-dai-component",
+};
+
+static int vc4_hdmi_audio_cpu_dai_probe(struct snd_soc_dai *dai)
+{
+ struct vc4_hdmi *hdmi = dai_to_hdmi(dai);
+
+ snd_soc_dai_init_dma_data(dai, &hdmi->audio.dma_data, NULL);
+
+ return 0;
+}
+
+static struct snd_soc_dai_driver vc4_hdmi_audio_cpu_dai_drv = {
+ .name = "vc4-hdmi-cpu-dai",
+ .probe = vc4_hdmi_audio_cpu_dai_probe,
+ .playback = {
+ .stream_name = "Playback",
+ .channels_min = 1,
+ .channels_max = 8,
+ .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,
+ .formats = SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_LE,
+ },
+ .ops = &vc4_hdmi_audio_dai_ops,
+};
+
+static const struct snd_dmaengine_pcm_config pcm_conf = {
+ .chan_names[SNDRV_PCM_STREAM_PLAYBACK] = "audio-rx",
+ .prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config,
+};
+
+static int vc4_hdmi_audio_init(struct vc4_hdmi *hdmi)
+{
+ struct snd_soc_dai_link *dai_link = &hdmi->audio.link;
+ struct snd_soc_card *card = &hdmi->audio.card;
+ struct device *dev = &hdmi->pdev->dev;
+ const __be32 *addr;
+ int ret;
+
+ if (!of_find_property(dev->of_node, "dmas", NULL)) {
+ dev_warn(dev,
+ "'dmas' DT property is missing, no HDMI audio\n");
+ return 0;
+ }
+
+ /*
+ * Get the physical address of VC4_HD_MAI_DATA. We need to retrieve
+ * the bus address specified in the DT, because the physical address
+ * (the one returned by platform_get_resource()) is not appropriate
+ * for DMA transfers.
+ * This VC/MMU should probably be exposed to avoid this kind of hacks.
+ */
+ addr = of_get_address(dev->of_node, 1, NULL, NULL);
+ hdmi->audio.dma_data.addr = be32_to_cpup(addr) + VC4_HD_MAI_DATA;
+ hdmi->audio.dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+ hdmi->audio.dma_data.maxburst = 2;
+
+ ret = devm_snd_dmaengine_pcm_register(dev, &pcm_conf, 0);
+ if (ret) {
+ dev_err(dev, "Could not register PCM component: %d\n", ret);
+ return ret;
+ }
+
+ ret = devm_snd_soc_register_component(dev, &vc4_hdmi_audio_cpu_dai_comp,
+ &vc4_hdmi_audio_cpu_dai_drv, 1);
+ if (ret) {
+ dev_err(dev, "Could not register CPU DAI: %d\n", ret);
+ return ret;
+ }
+
+ /* register codec and codec dai */
+ ret = snd_soc_register_codec(dev, &vc4_hdmi_audio_codec_drv,
+ &vc4_hdmi_audio_codec_dai_drv, 1);
+ if (ret) {
+ dev_err(dev, "Could not register codec: %d\n", ret);
+ return ret;
+ }
+
+ dai_link->name = "MAI";
+ dai_link->stream_name = "MAI PCM";
+ dai_link->codec_dai_name = vc4_hdmi_audio_codec_dai_drv.name;
+ dai_link->cpu_dai_name = dev_name(dev);
+ dai_link->codec_name = dev_name(dev);
+ dai_link->platform_name = dev_name(dev);
+
+ card->dai_link = dai_link;
+ card->num_links = 1;
+ card->name = "vc4-hdmi";
+ card->dev = dev;
+
+ /*
+ * Be careful, snd_soc_register_card() calls dev_set_drvdata() and
+ * stores a pointer to the snd card object in dev->driver_data. This
+ * means we cannot use it for something else. The hdmi back-pointer is
+ * now stored in card->drvdata and should be retrieved with
+ * snd_soc_card_get_drvdata() if needed.
+ */
+ snd_soc_card_set_drvdata(card, hdmi);
+ ret = devm_snd_soc_register_card(dev, card);
+ if (ret) {
+ dev_err(dev, "Could not register sound card: %d\n", ret);
+ goto unregister_codec;
+ }
+
+ return 0;
+
+unregister_codec:
+ snd_soc_unregister_codec(dev);
+
+ return ret;
+}
+
+static void vc4_hdmi_audio_cleanup(struct vc4_hdmi *hdmi)
+{
+ struct device *dev = &hdmi->pdev->dev;
+
+ /*
+ * If drvdata is not set this means the audio card was not
+ * registered, just skip codec unregistration in this case.
+ */
+ if (dev_get_drvdata(dev))
+ snd_soc_unregister_codec(dev);
+}
+
static int vc4_hdmi_bind(struct device *dev, struct device *master, void *data)
{
struct platform_device *pdev = to_platform_device(dev);
@@ -720,6 +1206,10 @@ static int vc4_hdmi_bind(struct device *dev, struct device *master, void *data)
goto err_destroy_encoder;
}

+ ret = vc4_hdmi_audio_init(hdmi);
+ if (ret)
+ goto err_destroy_encoder;
+
return 0;

err_destroy_encoder:
@@ -741,6 +1231,8 @@ static void vc4_hdmi_unbind(struct device *dev, struct device *master,
struct vc4_dev *vc4 = drm->dev_private;
struct vc4_hdmi *hdmi = vc4->hdmi;

+ vc4_hdmi_audio_cleanup(hdmi);
+
vc4_hdmi_connector_destroy(hdmi->connector);
vc4_hdmi_encoder_destroy(hdmi->encoder);

diff --git a/drivers/gpu/drm/vc4/vc4_regs.h b/drivers/gpu/drm/vc4/vc4_regs.h
index 385405a2df05..932093936178 100644
--- a/drivers/gpu/drm/vc4/vc4_regs.h
+++ b/drivers/gpu/drm/vc4/vc4_regs.h
@@ -446,11 +446,62 @@
#define VC4_HDMI_HOTPLUG 0x00c
# define VC4_HDMI_HOTPLUG_CONNECTED BIT(0)

+/* 3 bits per field, where each field maps from that corresponding MAI
+ * bus channel to the given HDMI channel.
+ */
+#define VC4_HDMI_MAI_CHANNEL_MAP 0x090
+
+#define VC4_HDMI_MAI_CONFIG 0x094
+# define VC4_HDMI_MAI_CONFIG_FORMAT_REVERSE BIT(27)
+# define VC4_HDMI_MAI_CONFIG_BIT_REVERSE BIT(26)
+# define VC4_HDMI_MAI_CHANNEL_MASK_MASK VC4_MASK(15, 0)
+# define VC4_HDMI_MAI_CHANNEL_MASK_SHIFT 0
+
+/* Last received format word on the MAI bus. */
+#define VC4_HDMI_MAI_FORMAT 0x098
+
+#define VC4_HDMI_AUDIO_PACKET_CONFIG 0x09c
+# define VC4_HDMI_AUDIO_PACKET_ZERO_DATA_ON_SAMPLE_FLAT BIT(29)
+# define VC4_HDMI_AUDIO_PACKET_ZERO_DATA_ON_INACTIVE_CHANNELS BIT(24)
+# define VC4_HDMI_AUDIO_PACKET_FORCE_SAMPLE_PRESENT BIT(19)
+# define VC4_HDMI_AUDIO_PACKET_FORCE_B_FRAME BIT(18)
+# define VC4_HDMI_AUDIO_PACKET_B_FRAME_IDENTIFIER_MASK VC4_MASK(13, 10)
+# define VC4_HDMI_AUDIO_PACKET_B_FRAME_IDENTIFIER_SHIFT 10
+/* If set, then multichannel, otherwise 2 channel. */
+# define VC4_HDMI_AUDIO_PACKET_AUDIO_LAYOUT BIT(9)
+/* If set, then AUDIO_LAYOUT overrides audio_cea_mask */
+# define VC4_HDMI_AUDIO_PACKET_FORCE_AUDIO_LAYOUT BIT(8)
+# define VC4_HDMI_AUDIO_PACKET_CEA_MASK_MASK VC4_MASK(7, 0)
+# define VC4_HDMI_AUDIO_PACKET_CEA_MASK_SHIFT 0
+
#define VC4_HDMI_RAM_PACKET_CONFIG 0x0a0
# define VC4_HDMI_RAM_PACKET_ENABLE BIT(16)

#define VC4_HDMI_RAM_PACKET_STATUS 0x0a4

+#define VC4_HDMI_CRP_CFG 0x0a8
+/* When set, the CTS_PERIOD counts based on MAI bus sync pulse instead
+ * of pixel clock.
+ */
+# define VC4_HDMI_CRP_USE_MAI_BUS_SYNC_FOR_CTS BIT(26)
+/* When set, no CRP packets will be sent. */
+# define VC4_HDMI_CRP_CFG_DISABLE BIT(25)
+/* If set, generates CTS values based on N, audio clock, and video
+ * clock. N must be divisible by 128.
+ */
+# define VC4_HDMI_CRP_CFG_EXTERNAL_CTS_EN BIT(24)
+# define VC4_HDMI_CRP_CFG_N_MASK VC4_MASK(19, 0)
+# define VC4_HDMI_CRP_CFG_N_SHIFT 0
+
+/* 20-bit fields containing CTS values to be transmitted if !EXTERNAL_CTS_EN */
+#define VC4_HDMI_CTS_0 0x0ac
+#define VC4_HDMI_CTS_1 0x0b0
+/* 20-bit fields containing number of clocks to send CTS0/1 before
+ * switching to the other one.
+ */
+#define VC4_HDMI_CTS_PERIOD_0 0x0b4
+#define VC4_HDMI_CTS_PERIOD_1 0x0b8
+
#define VC4_HDMI_HORZA 0x0c4
# define VC4_HDMI_HORZA_VPOS BIT(14)
# define VC4_HDMI_HORZA_HPOS BIT(13)
@@ -512,7 +563,11 @@

#define VC4_HDMI_TX_PHY_RESET_CTL 0x2c0

-#define VC4_HDMI_GCP_0 0x400
+#define VC4_HDMI_TX_PHY_CTL0 0x2c4
+# define VC4_HDMI_TX_PHY_RNG_PWRDN BIT(25)
+
+#define VC4_HDMI_GCP(x) (0x400 + ((x) * 0x4))
+#define VC4_HDMI_RAM_PACKET(x) (0x400 + ((x) * 0x24))
#define VC4_HDMI_PACKET_STRIDE 0x24

#define VC4_HD_M_CTL 0x00c
@@ -522,6 +577,56 @@
# define VC4_HD_M_ENABLE BIT(0)

#define VC4_HD_MAI_CTL 0x014
+/* Set when audio stream is received at a slower rate than the
+ * sampling period, so MAI fifo goes empty. Write 1 to clear.
+ */
+# define VC4_HD_MAI_CTL_DLATE BIT(15)
+# define VC4_HD_MAI_CTL_BUSY BIT(14)
+# define VC4_HD_MAI_CTL_CHALIGN BIT(13)
+# define VC4_HD_MAI_CTL_WHOLSMP BIT(12)
+# define VC4_HD_MAI_CTL_FULL BIT(11)
+# define VC4_HD_MAI_CTL_EMPTY BIT(10)
+# define VC4_HD_MAI_CTL_FLUSH BIT(9)
+/* If set, MAI bus generates SPDIF (bit 31) parity instead of passing
+ * through.
+ */
+# define VC4_HD_MAI_CTL_PAREN BIT(8)
+# define VC4_HD_MAI_CTL_CHNUM_MASK VC4_MASK(7, 4)
+# define VC4_HD_MAI_CTL_CHNUM_SHIFT 4
+# define VC4_HD_MAI_CTL_ENABLE BIT(3)
+/* Underflow error status bit, write 1 to clear. */
+# define VC4_HD_MAI_CTL_ERRORE BIT(2)
+/* Overflow error status bit, write 1 to clear. */
+# define VC4_HD_MAI_CTL_ERRORF BIT(1)
+/* Single-shot reset bit. Read value is undefined. */
+# define VC4_HD_MAI_CTL_RESET BIT(0)
+
+#define VC4_HD_MAI_THR 0x018
+# define VC4_HD_MAI_THR_PANICHIGH_MASK VC4_MASK(29, 24)
+# define VC4_HD_MAI_THR_PANICHIGH_SHIFT 24
+# define VC4_HD_MAI_THR_PANICLOW_MASK VC4_MASK(21, 16)
+# define VC4_HD_MAI_THR_PANICLOW_SHIFT 16
+# define VC4_HD_MAI_THR_DREQHIGH_MASK VC4_MASK(13, 8)
+# define VC4_HD_MAI_THR_DREQHIGH_SHIFT 8
+# define VC4_HD_MAI_THR_DREQLOW_MASK VC4_MASK(5, 0)
+# define VC4_HD_MAI_THR_DREQLOW_SHIFT 0
+
+/* Format header to be placed on the MAI data. Unused. */
+#define VC4_HD_MAI_FMT 0x01c
+
+/* Register for DMAing in audio data to be transported over the MAI
+ * bus to the Falcon core.
+ */
+#define VC4_HD_MAI_DATA 0x020
+
+/* Divider from HDMI HSM clock to MAI serial clock. Sampling period
+ * converges to N / (M + 1) cycles.
+ */
+#define VC4_HD_MAI_SMP 0x02c
+# define VC4_HD_MAI_SMP_N_MASK VC4_MASK(31, 8)
+# define VC4_HD_MAI_SMP_N_SHIFT 8
+# define VC4_HD_MAI_SMP_M_MASK VC4_MASK(7, 0)
+# define VC4_HD_MAI_SMP_M_SHIFT 0

#define VC4_HD_VID_CTL 0x038
# define VC4_HD_VID_CTL_ENABLE BIT(31)
--
2.11.0