mcu_mic_codec: Port initial driver from R11

This is just the initial driver code drop with no difference with R11.

Test: Manual
Bug: 243575790
Bug: 219605378
Signed-off-by: Florian Muller <mullerf@google.com>
Change-Id: If75606675f2955ac732699985754a9d8f43a0c20

5 files changed, 452 insertions, 0 deletions

diff --git a/Kbuild b/Kbuild
new file mode 100644
index 0000000..a37aaca
--- /dev/null
+++ b/Kbuild
@@ -0,0 +1,5 @@
+#
+# Makefile for the kernel ASOC MCU Mic codec driver.
+#
+
+obj-$(CONFIG_SND_SOC_MCU_MIC_CODEC) += mcu_mic_codec.o
diff --git a/Kconfig b/Kconfig
new file mode 100644
index 0000000..0ac3832
--- /dev/null
+++ b/Kconfig
@@ -0,0 +1,4 @@
+config SND_SOC_MCU_MIC_CODEC
+    tristate "ASOC MCU Mic codec"
+    help
+    	  ASOC Codec driver to communicate with Microphone on MCU.
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..8257f30
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,17 @@
+#
+# Makefile for ASOC MCU Mic codec driver.
+#
+
+default: all
+
+KBUILD_OPTIONS := CONFIG_SND_SOC_MCU_MIC_CODEC=m
+
+all:
+	$(MAKE) -C $(KERNEL_SRC) M=$(M) modules $(KBUILD_OPTIONS) KBUILD_EXTRA_SYMBOLS="$(OUT_DIR)/../exynos-google-cw-extra/drivers/sensorhub/nanohub/Module.symvers"
+
+modules_install:
+	$(MAKE) INSTALL_MOD_STRIP=1 M=$(M) -C $(KERNEL_SRC) modules_install
+
+clean::
+	rm -f *.o *.ko *.mod.c *.mod.o *~ .*.cmd Module.symvers
+	rm -rf .tmp_versions
diff --git a/mcu_mic_codec.c b/mcu_mic_codec.c
new file mode 100644
index 0000000..6284f94
--- /dev/null
+++ b/mcu_mic_codec.c
@@ -0,0 +1,414 @@
+/**
+ * The module represents a ASOC codec driver responsible for turning Microphone
+ * on the MCU on or off.
+ *
+ * Currently it's only a stub: it does not actually communicate with the MCU
+ * yet, that will be added later when the communication lib is available.
+ *
+ * Copyright 2020 Google LLC
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+#include <linux/completion.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+
+#define NANOHUB_AUDIO_CHANNEL_ID 16
+
+// Values here should match MCU FW values defined in audio_services.cc
+#define DMIC_MCU_MESSAGE_VERSION 1
+#define DMIC_MCU_MESSAGE_MIC_ON 0x01
+#define DMIC_MCU_MESSAGE_SAMPLE_RATE_KHZ 0x02
+#define DMIC_MCU_MESSAGE_CHANNEL 0x03
+#define DMIC_MCU_MESSAGE_GAIN 0x04
+
+enum dmic_mcu_channel {
+	DMIC_MCU_CHANNEL_LEFT,
+	DMIC_MCU_CHANNEL_RIGHT,
+	DMIC_MCU_CHANNEL_FALSE_STEREO,
+};
+
+static const char *const mcu_dmic_channel_enum_texts[] = {
+	"Left",
+	"Right",
+	"False Stereo",
+};
+
+static const unsigned int mcu_dmic_channel_enum_values[] = {
+	DMIC_MCU_CHANNEL_LEFT,
+	DMIC_MCU_CHANNEL_RIGHT,
+	DMIC_MCU_CHANNEL_FALSE_STEREO,
+};
+
+SOC_VALUE_ENUM_SINGLE_DECL(mcu_dmic_channel_enum, SND_SOC_NOPM, 0, 0,
+			   mcu_dmic_channel_enum_texts,
+			   mcu_dmic_channel_enum_values);
+
+extern ssize_t nanohub_send_message(int channel_id, const char *buffer,
+				    size_t length);
+
+struct mcu_mic_codec_data {
+	int mic_on;
+	int sample_rate_hz;
+	enum dmic_mcu_channel channel;
+	int gain;
+};
+
+static int dmic_mcu_send_message(struct snd_soc_component *component,
+				 char mcu_message_id, char data)
+{
+	char buffer[3];
+	ssize_t bytes;
+
+	buffer[0] = DMIC_MCU_MESSAGE_VERSION; // version
+	buffer[1] = mcu_message_id;	      // message identifier
+	buffer[2] = data;
+
+	bytes = nanohub_send_message(NANOHUB_AUDIO_CHANNEL_ID, buffer,
+				     sizeof(buffer));
+	if (bytes != sizeof(buffer)) {
+		dev_err(component->dev, "Bytes sent expected = %zd, actual = %zd\n",
+			sizeof(buffer), bytes);
+		return -EIO;
+	}
+	return 0;
+}
+
+// The callback that is called when ASOC needs to fetch the value of the
+// property 'DMIC_MCU Input Gain'.
+static int dmic_mcu_input_gain_get(struct snd_kcontrol *kcontrol,
+				   struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_component *component =
+		snd_soc_kcontrol_component(kcontrol);
+	struct mcu_mic_codec_data *codec_data =
+		snd_soc_component_get_drvdata(component);
+
+	dev_info(component->dev, "Called dmic_mcu_input_gain_get\n");
+
+	ucontrol->value.integer.value[0] = codec_data->gain;
+
+	dev_info(component->dev, "mcu_input_gain: %d\n", codec_data->gain);
+
+	return 0;
+}
+
+// The callback that is called when ASOC needs to set the value of the
+// property 'DMIC_MCU Input Gain'.
+static int dmic_mcu_input_gain_put(struct snd_kcontrol *kcontrol,
+				   struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_component *component =
+		snd_soc_kcontrol_component(kcontrol);
+	struct mcu_mic_codec_data *codec_data =
+		snd_soc_component_get_drvdata(component);
+	int value = ucontrol->value.integer.value[0];
+	int ret;
+
+	dev_info(component->dev, "Called dmic_mcu_input_gain_put\n");
+
+	if (value < 0 || value > 63) {
+		dev_info(component->dev,
+			 "Invalid value: %d, it must be between 0 and 63\n",
+			 value);
+		return -EINVAL;
+	}
+
+	ret = dmic_mcu_send_message(component, DMIC_MCU_MESSAGE_GAIN, value);
+	if (ret != 0) {
+		return ret;
+	}
+
+	codec_data->gain = value;
+	dev_info(component->dev, "new mcu_input_gain: %d\n", codec_data->gain);
+
+	return 0;
+}
+
+// The callback that is called when ASOC needs to fetch the value of the
+// property 'DMIC_MCU Channel'.
+static int dmic_mcu_channel_get(struct snd_kcontrol *kcontrol,
+				struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_component *component =
+		snd_soc_kcontrol_component(kcontrol);
+	struct mcu_mic_codec_data *codec_data =
+		snd_soc_component_get_drvdata(component);
+
+	dev_info(component->dev, "Called dmic_mcu_channel_get\n");
+
+	ucontrol->value.integer.value[0] = codec_data->channel;
+
+	dev_info(component->dev, "mcu_mic_channel: %d (%s)\n", codec_data->channel,
+		 mcu_dmic_channel_enum_texts[codec_data->channel]);
+
+	return 0;
+}
+
+// The callback that is called when ASOC needs to set the value of the
+// property 'DMIC_MCU Channel'.
+static int dmic_mcu_channel_put(struct snd_kcontrol *kcontrol,
+				struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_component *component =
+		snd_soc_kcontrol_component(kcontrol);
+	struct mcu_mic_codec_data *codec_data =
+		snd_soc_component_get_drvdata(component);
+	int value = ucontrol->value.integer.value[0];
+	int ret;
+
+	dev_info(component->dev, "Called dmic_mcu_channel_put\n");
+
+	if (value != DMIC_MCU_CHANNEL_LEFT &&
+		value != DMIC_MCU_CHANNEL_RIGHT &&
+	 	value != DMIC_MCU_CHANNEL_FALSE_STEREO) {
+		dev_info(component->dev,
+			 "Invalid value: %d, it must be Left, Right or 'False Stereo'.\n",
+			 value);
+		return -EINVAL;
+	}
+
+	ret = dmic_mcu_send_message(component, DMIC_MCU_MESSAGE_CHANNEL, value);
+	if (ret != 0) {
+		return ret;
+	}
+
+	codec_data->channel = value;
+	dev_info(component->dev, "new mcu_mic_channel: %d (%s)\n",
+		 codec_data->channel,
+		 mcu_dmic_channel_enum_texts[codec_data->channel]);
+
+	return 0;
+}
+
+// The callback that is called when ASOC needs to fetch the value of the
+// property 'DMIC_MCU Sample Rate'.
+static int dmic_mcu_sample_rate_get(struct snd_kcontrol *kcontrol,
+				    struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_component *component =
+		snd_soc_kcontrol_component(kcontrol);
+	struct mcu_mic_codec_data *codec_data =
+		snd_soc_component_get_drvdata(component);
+	dev_info(component->dev, "Called dmic_mcu_sample_rate_get\n");
+	ucontrol->value.integer.value[0] = codec_data->sample_rate_hz;
+	dev_info(component->dev, "mcu_mic_sample_rate: %d\n",
+		 codec_data->sample_rate_hz);
+	return 0;
+}
+
+// The callback that is called when ASOC needs to set the value of the
+// property 'DMIC_MCU Sample Rate'.
+static int dmic_mcu_sample_rate_put(struct snd_kcontrol *kcontrol,
+				    struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_component *component =
+		snd_soc_kcontrol_component(kcontrol);
+	struct mcu_mic_codec_data *codec_data =
+		snd_soc_component_get_drvdata(component);
+	int value = ucontrol->value.integer.value[0];
+	int ret;
+
+	dev_info(component->dev, "Called dmic_mcu_sample_rate_put\n");
+
+	if (value != 8000 && value != 16000 && value != 48000) {
+		dev_info(component->dev,
+			 "Invalid Sample Rate: %d. (Valid rates: 8000, 16000, 48000 Hertz)\n",
+			 value);
+		return -EINVAL;
+	}
+
+	ret = dmic_mcu_send_message(component, DMIC_MCU_MESSAGE_SAMPLE_RATE_KHZ,
+				    value / 1000);
+	if (ret != 0) {
+		return ret;
+	}
+
+	codec_data->sample_rate_hz = value;
+	dev_info(component->dev, "new mcu_mic_sample_rate: %d\n",
+		 codec_data->sample_rate_hz);
+
+	return 0;
+}
+
+// The callback that is called when ASOC needs to fetch the value of the
+// property 'DMIC_MCU On'.
+static int dmic_mcu_on_get(struct snd_kcontrol *kcontrol,
+			   struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_component *component =
+		snd_soc_kcontrol_component(kcontrol);
+	struct mcu_mic_codec_data *codec_data =
+		snd_soc_component_get_drvdata(component);
+
+	dev_info(component->dev, "Called dmic_mcu_on_get\n");
+
+	ucontrol->value.integer.value[0] = codec_data->mic_on;
+
+	dev_info(component->dev, "mcu_mic_on: %d\n", codec_data->mic_on);
+
+	return 0;
+}
+
+// The callback that is called when ASOC needs to set the value of the
+// property 'DMIC_MCU On'.
+static int dmic_mcu_on_put(struct snd_kcontrol *kcontrol,
+			   struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_component *component =
+		snd_soc_kcontrol_component(kcontrol);
+	struct mcu_mic_codec_data *codec_data =
+		snd_soc_component_get_drvdata(component);
+	int value = ucontrol->value.integer.value[0];
+	int ret;
+
+	dev_info(component->dev, "Called static int dmic_mcu_on_put\n");
+
+	if (value != 0 && value != 1) {
+		dev_info(component->dev,
+			 "Invalid value: %d, it must be 1 or 0.\n", value);
+		return -EINVAL;
+	}
+
+	ret = dmic_mcu_send_message(component, DMIC_MCU_MESSAGE_MIC_ON,
+				    value ? 1 : 0);
+	if (ret != 0) {
+		return ret;
+	}
+
+	codec_data->mic_on = value;
+	dev_info(component->dev, "new mcu_mic_on: %d\n", codec_data->mic_on);
+
+	return 0;
+}
+
+static const struct snd_kcontrol_new snd_controls[] = {
+	// Defines a property DMIC_MCU On.
+	// It can be switched in console for example using tinyalsa:
+	// tinymix 'DMIC_MCU On' 1
+	SOC_SINGLE_EXT("DMIC_MCU On", SND_SOC_NOPM, 0, 1, 0, dmic_mcu_on_get,
+		       dmic_mcu_on_put),
+	SOC_SINGLE_EXT("DMIC_MCU Sample Rate", SND_SOC_NOPM, 0, 48000, 0,
+		       dmic_mcu_sample_rate_get, dmic_mcu_sample_rate_put),
+	SOC_VALUE_ENUM_EXT("DMIC_MCU Channel", mcu_dmic_channel_enum,
+			   dmic_mcu_channel_get, dmic_mcu_channel_put),
+	// Input Gain is mapped from [-32, 31] to [0, 63]. This is because
+	// tinymix does not accept negative numbers. It processes the
+	// negative sign as an argument option prefix.
+	SOC_SINGLE_EXT("DMIC_MCU Input Gain", SND_SOC_NOPM, 0, 63, 0,
+		       dmic_mcu_input_gain_get, dmic_mcu_input_gain_put),
+};
+
+static int mcu_codec_probe(struct snd_soc_component *component)
+{
+	dev_info(component->dev, "Called mcu_codec_probe.\n");
+
+	return 0;
+}
+
+static void mcu_codec_remove(struct snd_soc_component *component)
+{
+	dev_info(component->dev, "Called mcu_codec_remove.\n");
+}
+
+static struct snd_soc_component_driver mcu_mic_soc_component_driver = {
+	.probe = mcu_codec_probe,
+	.remove = mcu_codec_remove,
+	.controls = snd_controls,
+	.num_controls = ARRAY_SIZE(snd_controls),
+};
+
+/*
+ * The codec DAI driver. It's properties are not used at the moment, as the main
+ * goal of the codec is to turn the Mic on/off.
+ */
+static struct snd_soc_dai_driver mcu_mic_soc_dai_driver = {
+	.name = "mcu-mic-codec-dai",
+	.capture = {
+			.stream_name = "Capture",
+			.channels_min = 1,
+			.channels_max = 1,
+			.rates = SNDRV_PCM_RATE_48000,
+			.formats = (SNDRV_PCM_FMTBIT_S16_LE |
+				    SNDRV_PCM_FMTBIT_U16_LE),
+		},
+};
+
+static int mcu_mic_probe(struct platform_device *pdev)
+{
+	int ret;
+	// Structure used to store mcu dmic state:
+	// [on/off] 1: it is on, 0: it is off.
+	// [sample rate]: Units of hertz
+	struct mcu_mic_codec_data *codec_data;
+
+	dev_info(&pdev->dev, "Called mcu_mic_probe\n");
+
+	codec_data = devm_kzalloc(&pdev->dev, sizeof(struct mcu_mic_codec_data),
+				  GFP_KERNEL);
+	if (!codec_data) {
+		dev_err(&pdev->dev, "No memory for codec_data\n");
+		return -ENOMEM;
+	}
+	codec_data->mic_on = 0;
+	codec_data->sample_rate_hz = 16000;
+	codec_data->channel = DMIC_MCU_CHANNEL_RIGHT;
+	// gain is offset by 32. Therefore 32 means 0 gain
+	codec_data->gain = 37;
+	platform_set_drvdata(pdev, codec_data);
+
+	ret = snd_soc_register_component(&pdev->dev,
+					 &mcu_mic_soc_component_driver,
+					 &mcu_mic_soc_dai_driver, 1);
+
+	dev_info(&pdev->dev, "mcu_mic_probe ret: %d\n", ret);
+
+	return ret;
+}
+
+static int mcu_mic_remove(struct platform_device *pdev)
+{
+	dev_info(&pdev->dev, "Called mcu_mic_remove\n");
+
+	snd_soc_unregister_component(&pdev->dev);
+
+	return 0;
+}
+
+const struct of_device_id mcu_mic_of_match[] = {
+	{
+		.compatible = "google,mcu_mic_codec",
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, mcu_mic_of_match);
+
+static struct platform_driver mcu_mic_driver = {
+	.driver = {
+			.name = "mcu_mic_codec",
+			.owner = THIS_MODULE,
+			.of_match_table = of_match_ptr(mcu_mic_of_match),
+		},
+	.probe = mcu_mic_probe,
+	.remove = mcu_mic_remove,
+};
+
+/* Register the platform driver */
+module_platform_driver(mcu_mic_driver);
+
+MODULE_DESCRIPTION("ASoC mcu mic codec driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:mcu_mic-codec");
diff --git a/mcu_mic_codec.txt b/mcu_mic_codec.txt
new file mode 100644
index 0000000..33fe809
--- /dev/null
+++ b/mcu_mic_codec.txt
@@ -0,0 +1,12 @@
+MCU Microphone ASOC DAI codec
+
+Required properties:
+
+  - compatible : "google,mcu_mic_codec"
+
+Example:
+
+mcu_mic_codec: audio_codec {
+	status = "okay";
+	compatible = "google,mcu_mic_codec";
+};