This patch adds a generic audio CODEC function to HDMI transmitters.
The CODEC is implemented as a library in a kernel module.
It handles both I2S and S/PDIF input, maintaining the audio format
and rates constraints according to the HDMI device parameters (EDID).
Audio source input switch is offered to the HDMI driver on start/stop
of audio streaming.
Signed-off-by: Jean-Francois Moine <moinejf at free.fr>
---
Documentation/devicetree/bindings/sound/hdmi2.txt | 32 ++++
include/sound/hdmi2.h | 24 +++
sound/soc/codecs/Kconfig | 3 +
sound/soc/codecs/Makefile | 2 +
sound/soc/codecs/hdmi2.c | 204 ++++++++++++++++++++++
5 files changed, 265 insertions(+)
create mode 100644 Documentation/devicetree/bindings/sound/hdmi2.txt
create mode 100644 include/sound/hdmi2.h
create mode 100644 sound/soc/codecs/hdmi2.c
diff --git a/Documentation/devicetree/bindings/sound/hdmi2.txt
b/Documentation/devicetree/bindings/sound/hdmi2.txt
new file mode 100644
index 0000000..5776370
--- /dev/null
+++ b/Documentation/devicetree/bindings/sound/hdmi2.txt
@@ -0,0 +1,32 @@
+Device-Tree bindings for the generic HDMI2 CODEC
+
+The HDMI2 CODEC describes how the audio controller is connected to the
+HDMI transmitter.
+These definitions are included in the HDMI transmiter description.
+
+Required properties:
+
+ - audio-ports: must contain one or two HDMI transmitter dependant
+ values identifying the audio sources.
+ The source type is given by the corresponding entry in
+ the audio-port-names property.
+
+ - audio-port-names: must contain entries matching the entries in
+ the audio-ports property.
+ Each value may be "i2s" or "spdif", giving the type of
+ the associated audio port.
+
+ - #sound-dai-cells: must be set to <1> for use with the simple-card.
+ The DAI 0 is the I2S input and the DAI 1 is the S/PDIF input.
+
+Example:
+
+ hdmi: hdmi-encoder {
+ compatible = "nxp,tda998x";
+ reg = <0x70>;
+ ...
+
+ audio-ports = <0x03>, <0x04>;
+ audio-port-names = "i2s", "spdif";
+ #sound-dai-cells = <1>;
+ };
diff --git a/include/sound/hdmi2.h b/include/sound/hdmi2.h
new file mode 100644
index 0000000..59e4148
--- /dev/null
+++ b/include/sound/hdmi2.h
@@ -0,0 +1,24 @@
+#ifndef SND_HDMI2_H
+#define SND_HDMI2_H
+/* hdmi2 codec data */
+struct hdmi2_codec {
+ u8 ports[2];
+ u16 source; /* audio DAI = index to ports[] */
+#define HDMI2_I2S 0
+#define HDMI2_SPDIF 1
+
+ unsigned sample_rate; /* current streaming values */
+ int sample_format;
+
+ u64 formats; /* HDMI (EDID) values */
+ unsigned max_channels;
+ struct snd_pcm_hw_constraint_list rate_constraints;
+
+ void (*start)(struct hdmi2_codec *audio, int full);
+ void (*stop)(struct hdmi2_codec *audio);
+};
+
+/* hdmi device -> hdmi2 codec */
+int hdmi2_codec_register(struct device *dev);
+void hdmi2_codec_unregister(struct device *dev);
+#endif
diff --git a/sound/soc/codecs/Kconfig b/sound/soc/codecs/Kconfig
index 8ab1547..1b8d81e 100644
--- a/sound/soc/codecs/Kconfig
+++ b/sound/soc/codecs/Kconfig
@@ -424,6 +424,9 @@ config SND_SOC_ES8328_SPI
tristate
select SND_SOC_ES8328
+config SND_SOC_HDMI2
+ tristate
+
config SND_SOC_ISABELLE
tristate
diff --git a/sound/soc/codecs/Makefile b/sound/soc/codecs/Makefile
index afba944..f59b1e6 100644
--- a/sound/soc/codecs/Makefile
+++ b/sound/soc/codecs/Makefile
@@ -53,6 +53,7 @@ snd-soc-dmic-objs := dmic.o
snd-soc-es8328-objs := es8328.o
snd-soc-es8328-i2c-objs := es8328-i2c.o
snd-soc-es8328-spi-objs := es8328-spi.o
+snd-soc-hdmi2-objs := hdmi2.o
snd-soc-isabelle-objs := isabelle.o
snd-soc-jz4740-codec-objs := jz4740.o
snd-soc-l3-objs := l3.o
@@ -228,6 +229,7 @@ obj-$(CONFIG_SND_SOC_DMIC) += snd-soc-dmic.o
obj-$(CONFIG_SND_SOC_ES8328) += snd-soc-es8328.o
obj-$(CONFIG_SND_SOC_ES8328_I2C)+= snd-soc-es8328-i2c.o
obj-$(CONFIG_SND_SOC_ES8328_SPI)+= snd-soc-es8328-spi.o
+obj-$(CONFIG_SND_SOC_HDMI2) += snd-soc-hdmi2.o
obj-$(CONFIG_SND_SOC_ISABELLE) += snd-soc-isabelle.o
obj-$(CONFIG_SND_SOC_JZ4740_CODEC) += snd-soc-jz4740-codec.o
obj-$(CONFIG_SND_SOC_L3) += snd-soc-l3.o
diff --git a/sound/soc/codecs/hdmi2.c b/sound/soc/codecs/hdmi2.c
new file mode 100644
index 0000000..8ba8ba6
--- /dev/null
+++ b/sound/soc/codecs/hdmi2.c
@@ -0,0 +1,204 @@
+/*
+ * ALSA SoC generic HDMI CODEC
+ *
+ * Copyright (C) 2014 Jean-Francois Moine
+ *
+ * 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 <linux/module.h>
+#include <sound/soc.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <linux/of.h>
+#include <linux/i2c.h>
+#include <sound/hdmi2.h>
+
+#define HDMI2_FORMATS (SNDRV_PCM_FMTBIT_S16_LE | \
+ SNDRV_PCM_FMTBIT_S20_3LE | \
+ SNDRV_PCM_FMTBIT_S24_LE | \
+ SNDRV_PCM_FMTBIT_S32_LE)
+
+static int hdmi2_startup(struct snd_pcm_substream *substream,
+ struct snd_soc_dai *dai)
+{
+ struct hdmi2_codec *audio = snd_soc_codec_get_drvdata(dai->codec);
+ struct snd_pcm_runtime *runtime = substream->runtime;
+
+ /* set the constraints */
+ snd_pcm_hw_constraint_list(runtime, 0,
+ SNDRV_PCM_HW_PARAM_RATE,
+ &audio->rate_constraints);
+ snd_pcm_hw_constraint_mask64(runtime,
+ SNDRV_PCM_HW_PARAM_FORMAT,
+ audio->formats);
+
+ snd_pcm_hw_constraint_minmax(runtime,
+ SNDRV_PCM_HW_PARAM_CHANNELS,
+ 1, audio->max_channels);
+ return 0;
+}
+
+static int hdmi2_hw_params(struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params,
+ struct snd_soc_dai *dai)
+{
+ struct hdmi2_codec *audio = snd_soc_codec_get_drvdata(dai->codec);
+
+ /* if same input and same parameters, do not do a full switch */
+ if (dai->id == audio->source &&
+ params_format(params) == audio->sample_format &&
+ params_rate(params) == audio->sample_rate) {
+ audio->start(audio, 0);
+ return 0;
+ }
+
+ audio->source = dai->id;
+ audio->sample_format = params_format(params);
+ audio->sample_rate = params_rate(params);
+ audio->start(audio, 1);
+ return 0;
+}
+
+static void hdmi2_shutdown(struct snd_pcm_substream *substream,
+ struct snd_soc_dai *dai)
+{
+ struct hdmi2_codec *audio = snd_soc_codec_get_drvdata(dai->codec);
+
+ audio->stop(audio);
+}
+
+static const struct snd_soc_dai_ops hdmi2_ops = {
+ .startup = hdmi2_startup,
+ .hw_params = hdmi2_hw_params,
+ .shutdown = hdmi2_shutdown,
+};
+
+static struct snd_soc_dai_driver hdmi2_dai[] = {
+ {
+ .name = "i2s-hifi",
+ .id = HDMI2_I2S,
+ .playback = {
+ .stream_name = "HDMI I2S Playback",
+ .channels_min = 1,
+ .channels_max = 8,
+ .rates = SNDRV_PCM_RATE_CONTINUOUS,
+ .rate_min = 5512,
+ .rate_max = 192000,
+ .formats = HDMI2_FORMATS,
+ },
+ .ops = &hdmi2_ops,
+ },
+ {
+ .name = "spdif-hifi",
+ .id = HDMI2_SPDIF,
+ .playback = {
+ .stream_name = "HDMI SPDIF Playback",
+ .channels_min = 1,
+ .channels_max = 2,
+ .rates = SNDRV_PCM_RATE_CONTINUOUS,
+ .rate_min = 22050,
+ .rate_max = 192000,
+ .formats = HDMI2_FORMATS,
+ },
+ .ops = &hdmi2_ops,
+ },
+};
+
+static const struct snd_soc_dapm_widget hdmi2_widgets[] = {
+ SND_SOC_DAPM_OUTPUT("hdmi-out"),
+};
+static const struct snd_soc_dapm_route hdmi2_routes[] = {
+ { "hdmi-out", NULL, "HDMI I2S Playback" },
+ { "hdmi-out", NULL, "HDMI SPDIF Playback" },
+};
+
+/*
+ * The HDMI driver must set the i2c client data to the hdmi2_codec
+ */
+static int hdmi2_probe(struct snd_soc_codec *codec)
+{
+ struct i2c_client *i2c_client = to_i2c_client(codec->dev);
+ struct hdmi2_codec *audio = i2c_get_clientdata(i2c_client);
+ struct device_node *np = codec->dev->of_node;
+ int i, j, ret;
+ const char *p;
+
+ if (!audio)
+ return -ENODEV;
+ snd_soc_codec_set_drvdata(codec, audio);
+
+ if (!np)
+ return 0;
+
+ /* get the audio input ports*/
+ for (i = 0; i < 2; i++) {
+ u32 port;
+
+ ret = of_property_read_u32_index(np, "audio-ports", i, &port);
+ if (ret) {
+ if (i == 0)
+ dev_err(codec->dev,
+ "bad or missing audio-ports\n");
+ break;
+ }
+ ret = of_property_read_string_index(np, "audio-port-names",
+ i, &p);
+ if (ret) {
+ dev_err(codec->dev,
+ "missing audio-port-names[%d]\n", i);
+ break;
+ }
+ if (strcmp(p, "i2s") == 0) {
+ j = 0;
+ } else if (strcmp(p, "spdif") == 0) {
+ j = 1;
+ } else {
+ dev_err(codec->dev,
+ "bad audio-port-names '%s'\n", p);
+ break;
+ }
+ audio->ports[j] = port;
+ }
+ return 0;
+}
+
+static const struct snd_soc_codec_driver soc_codec_hdmi2 = {
+ .probe = hdmi2_probe,
+ .dapm_widgets = hdmi2_widgets,
+ .num_dapm_widgets = ARRAY_SIZE(hdmi2_widgets),
+ .dapm_routes = hdmi2_routes,
+ .num_dapm_routes = ARRAY_SIZE(hdmi2_routes),
+};
+
+int hdmi2_codec_register(struct device *dev)
+{
+ return snd_soc_register_codec(dev,
+ &soc_codec_hdmi2,
+ hdmi2_dai, ARRAY_SIZE(hdmi2_dai));
+}
+EXPORT_SYMBOL(hdmi2_codec_register);
+
+void hdmi2_codec_unregister(struct device *dev)
+{
+ snd_soc_unregister_codec(dev);
+}
+EXPORT_SYMBOL(hdmi2_codec_unregister);
+
+/* -- module insert / remove -- */
+MODULE_AUTHOR("Jean-Francois Moine <moinejf at free.fr>");
+MODULE_DESCRIPTION("HDMI2 CODEC");
+MODULE_LICENSE("GPL");
+
+static int __init hdmi2_codec_init(void)
+{
+ return 0;
+}
+static void __exit hdmi2_codec_exit(void)
+{
+}
+
+module_init(hdmi2_codec_init);
+module_exit(hdmi2_codec_exit);
--
2.1.0
