ASoC: pcm179x: Add I2C interface driver

The PCM179x family supports both SPI and I2C. This patch adds support
for the I2C interface.
Signed-off-by: Jacob Siverskog <jacob@teenage.engineering>
Reviewed-by: Johan Hovold <johan@kernel.org>
Acked-by: Michael Trimarchi <michael@amarulasolutions.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/pcm179x.txt

 Texas Instruments pcm179x DT bindings
 
-This driver supports the SPI bus.
+This driver supports both the I2C and SPI bus.
 
 Required properties:
 
@@ -9,6 +9,11 @@ Required properties:
 For required properties on SPI, please consult
 Documentation/devicetree/bindings/spi/spi-bus.txt
 
+Required properties on I2C:
+
+ - reg: the I2C address
+
+
 Examples:
 
 	codec_spi: 1792a@0 {
@@ -16,3 +21,7 @@ Examples:
 		spi-max-frequency = <600000>;
 	};
 
+	codec_i2c: 1792a@4c {
+		compatible = "ti,pcm1792a";
+		reg = <0x4c>;
+	};

sound/soc/codecs/Kconfig

@@ -87,6 +87,7 @@ config SND_SOC_ALL_CODECS
 	select SND_SOC_ML26124 if I2C
 	select SND_SOC_NAU8825 if I2C
 	select SND_SOC_PCM1681 if I2C
+	select SND_SOC_PCM179X_I2C if I2C
 	select SND_SOC_PCM179X_SPI if SPI_MASTER
 	select SND_SOC_PCM3008
 	select SND_SOC_PCM3168A_I2C if I2C
@@ -529,6 +530,14 @@ config SND_SOC_PCM1681
 config SND_SOC_PCM179X
 	tristate
 
+config SND_SOC_PCM179X_I2C
+	tristate "Texas Instruments PCM179X CODEC (I2C)"
+	depends on I2C
+	select SND_SOC_PCM179X
+	help
+	  Enable support for Texas Instruments PCM179x CODEC.
+	  Select this if your PCM179x is connected via an I2C bus.
+
 config SND_SOC_PCM179X_SPI
 	tristate "Texas Instruments PCM179X CODEC (SPI)"
 	depends on SPI_MASTER

sound/soc/codecs/Makefile

@@ -81,6 +81,7 @@ snd-soc-ml26124-objs := ml26124.o
 snd-soc-nau8825-objs := nau8825.o
 snd-soc-pcm1681-objs := pcm1681.o
 snd-soc-pcm179x-codec-objs := pcm179x.o
+snd-soc-pcm179x-i2c-objs := pcm179x-i2c.o
 snd-soc-pcm179x-spi-objs := pcm179x-spi.o
 snd-soc-pcm3008-objs := pcm3008.o
 snd-soc-pcm3168a-objs := pcm3168a.o
@@ -286,6 +287,7 @@ obj-$(CONFIG_SND_SOC_ML26124)	+= snd-soc-ml26124.o
 obj-$(CONFIG_SND_SOC_NAU8825)   += snd-soc-nau8825.o
 obj-$(CONFIG_SND_SOC_PCM1681)	+= snd-soc-pcm1681.o
 obj-$(CONFIG_SND_SOC_PCM179X)	+= snd-soc-pcm179x-codec.o
+obj-$(CONFIG_SND_SOC_PCM179X_I2C)	+= snd-soc-pcm179x-i2c.o
 obj-$(CONFIG_SND_SOC_PCM179X_SPI)	+= snd-soc-pcm179x-spi.o
 obj-$(CONFIG_SND_SOC_PCM3008)	+= snd-soc-pcm3008.o
 obj-$(CONFIG_SND_SOC_PCM3168A)	+= snd-soc-pcm3168a.o

sound/soc/codecs/pcm179x-i2c.c

+/*
+ * PCM179X ASoC I2C driver
+ *
+ * Copyright (c) Teenage Engineering AB 2016
+ *
+ *     Jacob Siverskog <jacob@teenage.engineering>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * 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/module.h>
+#include <linux/of.h>
+#include <linux/i2c.h>
+#include <linux/regmap.h>
+
+#include "pcm179x.h"
+
+static int pcm179x_i2c_probe(struct i2c_client *client,
+			      const struct i2c_device_id *id)
+{
+	struct regmap *regmap;
+	int ret;
+
+	regmap = devm_regmap_init_i2c(client, &pcm179x_regmap_config);
+	if (IS_ERR(regmap)) {
+		ret = PTR_ERR(regmap);
+		dev_err(&client->dev, "Failed to allocate regmap: %d\n", ret);
+		return ret;
+	}
+
+	return pcm179x_common_init(&client->dev, regmap);
+}
+
+static int pcm179x_i2c_remove(struct i2c_client *client)
+{
+	return pcm179x_common_exit(&client->dev);
+}
+
+static const struct of_device_id pcm179x_of_match[] = {
+	{ .compatible = "ti,pcm1792a", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, pcm179x_of_match);
+
+static const struct i2c_device_id pcm179x_i2c_ids[] = {
+	{ "pcm179x", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, pcm179x_i2c_ids);
+
+static struct i2c_driver pcm179x_i2c_driver = {
+	.driver = {
+		.name	= "pcm179x",
+		.of_match_table = of_match_ptr(pcm179x_of_match),
+	},
+	.id_table	= pcm179x_i2c_ids,
+	.probe		= pcm179x_i2c_probe,
+	.remove		= pcm179x_i2c_remove,
+};
+
+module_i2c_driver(pcm179x_i2c_driver);
+
+MODULE_DESCRIPTION("ASoC PCM179X I2C driver");
+MODULE_AUTHOR("Jacob Siverskog <jacob@teenage.engineering>");
+MODULE_LICENSE("GPL");