From 81151cfb6bfe69f1c5a52b795eb005226a322c9e Mon Sep 17 00:00:00 2001
From: Philipp Zabel
Date: Wed, 20 Apr 2016 10:59:58 +0200
Subject: [PATCH] ASoC: hdmi-codec: Add ELD control
ALSA doesn't know about all the different compressed audio formats,
so there is no interface to let userspace enumerate the formats that
are supported by the connected sink. Exporting the raw ELD bytes to
userspace allows an application to select the appropriate audio format
depending on the current capabilities of the connected HDMI sink device.
Usually userspace then just pretends to ALSA that the data is in one of
the raw 16-bit PCM audio formats and relies on the IEC controls to tell
the sink how to interpret the data.
Signed-off-by: Philipp Zabel
Reviewed-by: Jyri Sarha
Tested-by: Jyri Sarha
Signed-off-by: Mark Brown
---
sound/soc/codecs/hdmi-codec.c | 38 +++++++++++++++++++++++++++++++++++
1 file changed, 38 insertions(+)
diff --git a/sound/soc/codecs/hdmi-codec.c b/sound/soc/codecs/hdmi-codec.c
index b46b8edb9319..c78333b4311d 100644
--- a/sound/soc/codecs/hdmi-codec.c
+++ b/sound/soc/codecs/hdmi-codec.c
@@ -47,6 +47,42 @@ enum {
DAI_ID_SPDIF,
};
+static int hdmi_eld_ctl_info(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_info *uinfo)
+{
+ struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
+ struct hdmi_codec_priv *hcp = snd_soc_component_get_drvdata(component);
+
+ uinfo->type = SNDRV_CTL_ELEM_TYPE_BYTES;
+ uinfo->count = sizeof(hcp->eld);
+
+ return 0;
+}
+
+static int hdmi_eld_ctl_get(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *ucontrol)
+{
+ struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
+ struct hdmi_codec_priv *hcp = snd_soc_component_get_drvdata(component);
+
+ mutex_lock(&hcp->eld_lock);
+ memcpy(ucontrol->value.bytes.data, hcp->eld, sizeof(hcp->eld));
+ mutex_unlock(&hcp->eld_lock);
+
+ return 0;
+}
+
+static const struct snd_kcontrol_new hdmi_controls[] = {
+ {
+ .access = SNDRV_CTL_ELEM_ACCESS_READ |
+ SNDRV_CTL_ELEM_ACCESS_VOLATILE,
+ .iface = SNDRV_CTL_ELEM_IFACE_PCM,
+ .name = "ELD",
+ .info = hdmi_eld_ctl_info,
+ .get = hdmi_eld_ctl_get,
+ },
+};
+
static int hdmi_codec_new_stream(struct snd_pcm_substream *substream,
struct snd_soc_dai *dai)
{
@@ -312,6 +348,8 @@ static const struct snd_soc_dai_driver hdmi_spdif_dai = {
};
static struct snd_soc_codec_driver hdmi_codec = {
+ .controls = hdmi_controls,
+ .num_controls = ARRAY_SIZE(hdmi_controls),
.dapm_widgets = hdmi_widgets,
.num_dapm_widgets = ARRAY_SIZE(hdmi_widgets),
.dapm_routes = hdmi_routes,
--
2.39.5