ASoC: ics43432: Add codec driver for InvenSense ICS-43432

Add support for the InvenSense ICS-43432 I2S MEMS microphone.

This is a non-software-configurable MEMS microphone with I2S output.

Tested on a setup with a single ICS-43432 (the device itself supports
stereo operation using a hardware pin controlling left vs. right channel
output).
Signed-off-by: Ricard Wanderlof <ricardw@axis.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/ics43432.txt

+Invensense ICS-43432 MEMS microphone with I2S output.
+
+There are no software configuration options for this device, indeed, the only
+host connection is the I2S interface. Apart from requirements on clock
+frequency (460 kHz to 3.379 MHz according to the data sheet) there must be
+64 clock cycles in each stereo output frame; 24 of the 32 available bits
+contain audio data. A hardware pin determines if the device outputs data
+on the left or right channel of the I2S frame.
+
+Required properties:
+  - compatible : Must be "invensense,ics43432"
+
+Example:
+
+	ics43432: ics43432 {
+		compatible = "invensense,ics43432";
+	};

Documentation/devicetree/bindings/vendor-prefixes.txt

@@ -110,6 +110,7 @@ ingenic	Ingenic Semiconductor
 innolux	Innolux Corporation
 intel	Intel Corporation
 intercontrol	Inter Control Group
+invensense	InvenSense Inc.
 isee	ISEE 2007 S.L.
 isil	Intersil
 karo	Ka-Ro electronics GmbH

sound/soc/codecs/Kconfig

@@ -62,6 +62,7 @@ config SND_SOC_ALL_CODECS
 	select SND_SOC_BT_SCO
 	select SND_SOC_ES8328_SPI if SPI_MASTER
 	select SND_SOC_ES8328_I2C if I2C
+	select SND_SOC_ICS43432
 	select SND_SOC_ISABELLE if I2C
 	select SND_SOC_JZ4740_CODEC
 	select SND_SOC_LM4857 if I2C
@@ -446,6 +447,9 @@ config SND_SOC_ES8328_SPI
 	tristate
 	select SND_SOC_ES8328
 
+config SND_SOC_ICS43432
+	tristate
+
 config SND_SOC_ISABELLE
         tristate
 

sound/soc/codecs/Makefile

@@ -55,6 +55,7 @@ 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-ics43432-objs := ics43432.o
 snd-soc-isabelle-objs := isabelle.o
 snd-soc-jz4740-codec-objs := jz4740.o
 snd-soc-l3-objs := l3.o
@@ -242,6 +243,7 @@ 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-$(CONFIG_SND_SOC_ICS43432)	+= snd-soc-ics43432.o
 obj-$(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

sound/soc/codecs/ics43432.c

+/*
+ * I2S MEMS microphone driver for InvenSense ICS-43432
+ *
+ * - Non configurable.
+ * - I2S interface, 64 BCLs per frame, 32 bits per channel, 24 bit data
+ *
+ * Copyright (c) 2015 Axis Communications AB
+ *
+ * Licensed under GPL2.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+#include <sound/initval.h>
+#include <sound/tlv.h>
+
+#define ICS43432_RATE_MIN 7190 /* Hz, from data sheet */
+#define ICS43432_RATE_MAX 52800  /* Hz, from data sheet */
+
+#define ICS43432_FORMATS (SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S32)
+
+static struct snd_soc_dai_driver ics43432_dai = {
+	.name = "ics43432-hifi",
+	.capture = {
+		.stream_name = "Capture",
+		.channels_min = 1,
+		.channels_max = 2,
+		.rate_min = ICS43432_RATE_MIN,
+		.rate_max = ICS43432_RATE_MAX,
+		.rates = SNDRV_PCM_RATE_CONTINUOUS,
+		.formats = ICS43432_FORMATS,
+	},
+};
+
+static struct snd_soc_codec_driver ics43432_codec_driver = {
+};
+
+static int ics43432_probe(struct platform_device *pdev)
+{
+	return snd_soc_register_codec(&pdev->dev, &ics43432_codec_driver,
+			&ics43432_dai, 1);
+}
+
+static int ics43432_remove(struct platform_device *pdev)
+{
+	snd_soc_unregister_codec(&pdev->dev);
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id ics43432_ids[] = {
+	{ .compatible = "invensense,ics43432", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ics43432_dt_ids);
+#endif
+
+static struct platform_driver ics43432_driver = {
+	.driver = {
+		.name = "ics43432",
+		.owner = THIS_MODULE,
+		.of_match_table = of_match_ptr(ics43432_ids),
+	},
+	.probe = ics43432_probe,
+	.remove = ics43432_remove,
+};
+
+module_platform_driver(ics43432_driver);
+
+MODULE_DESCRIPTION("ASoC ICS43432 driver");
+MODULE_AUTHOR("Ricard Wanderlof <ricardw@axis.com>");
+MODULE_LICENSE("GPLv2");