ASoC: Add ADAU1977 CODEC driver

This patch adds support for the ADAU1977, ADAU1978 and ADAU1979 audio CODEC
devices. They are a family of 4-channel differential input audio ADC devices.
They can be connected to either a SPI or I2C bus. The driver is implemented in
three modules, one main module (adau1977.ko) which implements the device logic
and one module each for SPI (adau1977-spi.ko) and I2C (adau1977-i2c.ko) bus
access.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@linaro.org>

1 files changed, 76 insertions, 0 deletions

diff --git a/sound/soc/codecs/adau1977-spi.c b/sound/soc/codecs/adau1977-spi.c
new file mode 100644
index 000000000000..b05cf5da3a94
--- /dev/null
+++ b/sound/soc/codecs/adau1977-spi.c
@@ -0,0 +1,76 @@
+/*
+ * ADAU1977/ADAU1978/ADAU1979 driver
+ *
+ * Copyright 2014 Analog Devices Inc.
+ *  Author: Lars-Peter Clausen <lars@metafoo.de>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+#include <sound/soc.h>
+
+#include "adau1977.h"
+
+static void adau1977_spi_switch_mode(struct device *dev)
+{
+	struct spi_device *spi = to_spi_device(dev);
+
+	/*
+	 * To get the device into SPI mode CLATCH has to be pulled low three
+	 * times.  Do this by issuing three dummy reads.
+	 */
+	spi_w8r8(spi, 0x00);
+	spi_w8r8(spi, 0x00);
+	spi_w8r8(spi, 0x00);
+}
+
+static int adau1977_spi_probe(struct spi_device *spi)
+{
+	const struct spi_device_id *id = spi_get_device_id(spi);
+	struct regmap_config config;
+
+	if (!id)
+		return -EINVAL;
+
+	config = adau1977_regmap_config;
+	config.val_bits = 8;
+	config.reg_bits = 16;
+	config.read_flag_mask = 0x1;
+
+	return adau1977_probe(&spi->dev,
+		devm_regmap_init_spi(spi, &config),
+		id->driver_data, adau1977_spi_switch_mode);
+}
+
+static int adau1977_spi_remove(struct spi_device *spi)
+{
+	snd_soc_unregister_codec(&spi->dev);
+	return 0;
+}
+
+static const struct spi_device_id adau1977_spi_ids[] = {
+	{ "adau1977", ADAU1977 },
+	{ "adau1978", ADAU1978 },
+	{ "adau1979", ADAU1978 },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, adau1977_spi_ids);
+
+static struct spi_driver adau1977_spi_driver = {
+	.driver = {
+		.name = "adau1977",
+		.owner = THIS_MODULE,
+	},
+	.probe = adau1977_spi_probe,
+	.remove = adau1977_spi_remove,
+	.id_table = adau1977_spi_ids,
+};
+module_spi_driver(adau1977_spi_driver);
+
+MODULE_DESCRIPTION("ASoC ADAU1977/ADAU1978/ADAU1979 driver");
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_LICENSE("GPL");