iio:ad5446: Add support for I2C based DACs

This patch adds support for I2C based single channel DACs to the ad5446
driver. Specifically AD5602, AD5612 and AD5622.

V1: from Lars-Peter Clausen <lars@metafoo.de>
V2: Split the device IDs into two enums and move them to the c file.

Signed-off-by: Jean-Francois Dagenais <jeff.dagenais@gmail.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

3 files changed, 293 insertions, 147 deletions

diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index 1be15fa9d61..293b61dcc55 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -57,11 +57,12 @@ config AD5624R_SPI
 
 config AD5446
 	tristate "Analog Devices AD5446 and similar single channel DACs driver"
-	depends on SPI
+	depends on (SPI_MASTER || I2C)
 	help
-	  Say yes here to build support for Analog Devices AD5444, AD5446, AD5450,
-	  AD5451, AD5452, AD5453, AD5512A, AD5541A, AD5542A, AD5543, AD5553, AD5601,
-	  AD5611, AD5620, AD5621, AD5640, AD5660, AD5662 DACs.
+	  Say yes here to build support for Analog Devices AD5602, AD5612, AD5622,
+	  AD5444, AD5446, AD5450, AD5451, AD5452, AD5453, AD5512A, AD5541A, AD5542A,
+	  AD5543, AD5553, AD5601, AD5611, AD5620, AD5621, AD5640, AD5660, AD5662
+	  DACs.
 
 	  To compile this driver as a module, choose M here: the
 	  module will be called ad5446.
diff --git a/drivers/iio/dac/ad5446.c b/drivers/iio/dac/ad5446.c
index 2ca5059ef89..241665b8183 100644
--- a/drivers/iio/dac/ad5446.c
+++ b/drivers/iio/dac/ad5446.c
@@ -14,6 +14,7 @@
 #include <linux/sysfs.h>
 #include <linux/list.h>
 #include <linux/spi/spi.h>
+#include <linux/i2c.h>
 #include <linux/regulator/consumer.h>
 #include <linux/err.h>
 #include <linux/module.h>
@@ -23,23 +24,6 @@
 
 #include "ad5446.h"
 
-static int ad5446_write(struct ad5446_state *st, unsigned val)
-{
-	__be16 data = cpu_to_be16(val);
-	return spi_write(st->spi, &data, sizeof(data));
-}
-
-static int ad5660_write(struct ad5446_state *st, unsigned val)
-{
-	uint8_t data[3];
-
-	data[0] = (val >> 16) & 0xFF;
-	data[1] = (val >> 8) & 0xFF;
-	data[2] = val & 0xFF;
-
-	return spi_write(st->spi, data, sizeof(data));
-}
-
 static const char * const ad5446_powerdown_modes[] = {
 	"1kohm_to_gnd", "100kohm_to_gnd", "three_state"
 };
@@ -110,7 +94,7 @@ static ssize_t ad5446_write_dac_powerdown(struct iio_dev *indio_dev,
 	return ret ? ret : len;
 }
 
-static const struct iio_chan_spec_ext_info ad5064_ext_info_powerdown[] = {
+static const struct iio_chan_spec_ext_info ad5446_ext_info_powerdown[] = {
 	{
 		.name = "powerdown",
 		.read = ad5446_read_dac_powerdown,
@@ -136,84 +120,7 @@ static const struct iio_chan_spec_ext_info ad5064_ext_info_powerdown[] = {
 	_AD5446_CHANNEL(bits, storage, shift, NULL)
 
 #define AD5446_CHANNEL_POWERDOWN(bits, storage, shift) \
-	_AD5446_CHANNEL(bits, storage, shift, ad5064_ext_info_powerdown)
-
-static const struct ad5446_chip_info ad5446_chip_info_tbl[] = {
-	[ID_AD5444] = {
-		.channel = AD5446_CHANNEL(12, 16, 2),
-		.write = ad5446_write,
-	},
-	[ID_AD5446] = {
-		.channel = AD5446_CHANNEL(14, 16, 0),
-		.write = ad5446_write,
-	},
-	[ID_AD5450] = {
-		.channel = AD5446_CHANNEL(8, 16, 6),
-		.write = ad5446_write,
-	},
-	[ID_AD5451] = {
-		.channel = AD5446_CHANNEL(10, 16, 4),
-		.write = ad5446_write,
-	},
-	[ID_AD5541A] = {
-		.channel = AD5446_CHANNEL(16, 16, 0),
-		.write = ad5446_write,
-	},
-	[ID_AD5512A] = {
-		.channel = AD5446_CHANNEL(12, 16, 4),
-		.write = ad5446_write,
-	},
-	[ID_AD5553] = {
-		.channel = AD5446_CHANNEL(14, 16, 0),
-		.write = ad5446_write,
-	},
-	[ID_AD5601] = {
-		.channel = AD5446_CHANNEL_POWERDOWN(8, 16, 6),
-		.write = ad5446_write,
-	},
-	[ID_AD5611] = {
-		.channel = AD5446_CHANNEL_POWERDOWN(10, 16, 4),
-		.write = ad5446_write,
-	},
-	[ID_AD5621] = {
-		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 2),
-		.write = ad5446_write,
-	},
-	[ID_AD5620_2500] = {
-		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 2),
-		.int_vref_mv = 2500,
-		.write = ad5446_write,
-	},
-	[ID_AD5620_1250] = {
-		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 2),
-		.int_vref_mv = 1250,
-		.write = ad5446_write,
-	},
-	[ID_AD5640_2500] = {
-		.channel = AD5446_CHANNEL_POWERDOWN(14, 16, 0),
-		.int_vref_mv = 2500,
-		.write = ad5446_write,
-	},
-	[ID_AD5640_1250] = {
-		.channel = AD5446_CHANNEL_POWERDOWN(14, 16, 0),
-		.int_vref_mv = 1250,
-		.write = ad5446_write,
-	},
-	[ID_AD5660_2500] = {
-		.channel = AD5446_CHANNEL_POWERDOWN(16, 16, 0),
-		.int_vref_mv = 2500,
-		.write = ad5660_write,
-	},
-	[ID_AD5660_1250] = {
-		.channel = AD5446_CHANNEL_POWERDOWN(16, 16, 0),
-		.int_vref_mv = 1250,
-		.write = ad5660_write,
-	},
-	[ID_AD5662] = {
-		.channel = AD5446_CHANNEL_POWERDOWN(16, 16, 0),
-		.write = ad5660_write,
-	},
-};
+	_AD5446_CHANNEL(bits, storage, shift, ad5446_ext_info_powerdown)
 
 static int ad5446_read_raw(struct iio_dev *indio_dev,
 			   struct iio_chan_spec const *chan,
@@ -272,14 +179,15 @@ static const struct iio_info ad5446_info = {
 	.driver_module = THIS_MODULE,
 };
 
-static int __devinit ad5446_probe(struct spi_device *spi)
+static int __devinit ad5446_probe(struct device *dev, const char *name,
+	const struct ad5446_chip_info *chip_info)
 {
 	struct ad5446_state *st;
 	struct iio_dev *indio_dev;
 	struct regulator *reg;
 	int ret, voltage_uv = 0;
 
-	reg = regulator_get(&spi->dev, "vcc");
+	reg = regulator_get(dev, "vcc");
 	if (!IS_ERR(reg)) {
 		ret = regulator_enable(reg);
 		if (ret)
@@ -294,16 +202,15 @@ static int __devinit ad5446_probe(struct spi_device *spi)
 		goto error_disable_reg;
 	}
 	st = iio_priv(indio_dev);
-	st->chip_info =
-		&ad5446_chip_info_tbl[spi_get_device_id(spi)->driver_data];
+	st->chip_info = chip_info;
 
-	spi_set_drvdata(spi, indio_dev);
+	dev_set_drvdata(dev, indio_dev);
 	st->reg = reg;
-	st->spi = spi;
+	st->dev = dev;
 
-	/* Establish that the iio_dev is a child of the spi device */
-	indio_dev->dev.parent = &spi->dev;
-	indio_dev->name = spi_get_device_id(spi)->name;
+	/* Establish that the iio_dev is a child of the device */
+	indio_dev->dev.parent = dev;
+	indio_dev->name = name;
 	indio_dev->info = &ad5446_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->channels = &st->chip_info->channel;
@@ -316,7 +223,7 @@ static int __devinit ad5446_probe(struct spi_device *spi)
 	else if (voltage_uv)
 		st->vref_mv = voltage_uv / 1000;
 	else
-		dev_warn(&spi->dev, "reference voltage unspecified\n");
+		dev_warn(dev, "reference voltage unspecified\n");
 
 	ret = iio_device_register(indio_dev);
 	if (ret)
@@ -336,9 +243,9 @@ error_put_reg:
 	return ret;
 }
 
-static int ad5446_remove(struct spi_device *spi)
+static int ad5446_remove(struct device *dev)
 {
-	struct iio_dev *indio_dev = spi_get_drvdata(spi);
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 	struct ad5446_state *st = iio_priv(indio_dev);
 
 	iio_device_unregister(indio_dev);
@@ -351,7 +258,133 @@ static int ad5446_remove(struct spi_device *spi)
 	return 0;
 }
 
-static const struct spi_device_id ad5446_id[] = {
+#if IS_ENABLED(CONFIG_SPI_MASTER)
+
+static int ad5446_write(struct ad5446_state *st, unsigned val)
+{
+	struct spi_device *spi = to_spi_device(st->dev);
+	__be16 data = cpu_to_be16(val);
+
+	return spi_write(spi, &data, sizeof(data));
+}
+
+static int ad5660_write(struct ad5446_state *st, unsigned val)
+{
+	struct spi_device *spi = to_spi_device(st->dev);
+	uint8_t data[3];
+
+	data[0] = (val >> 16) & 0xFF;
+	data[1] = (val >> 8) & 0xFF;
+	data[2] = val & 0xFF;
+
+	return spi_write(spi, data, sizeof(data));
+}
+
+/**
+ * ad5446_supported_spi_device_ids:
+ * The AD5620/40/60 parts are available in different fixed internal reference
+ * voltage options. The actual part numbers may look differently
+ * (and a bit cryptic), however this style is used to make clear which
+ * parts are supported here.
+ */
+enum ad5446_supported_spi_device_ids {
+	ID_AD5444,
+	ID_AD5446,
+	ID_AD5450,
+	ID_AD5451,
+	ID_AD5541A,
+	ID_AD5512A,
+	ID_AD5553,
+	ID_AD5601,
+	ID_AD5611,
+	ID_AD5621,
+	ID_AD5620_2500,
+	ID_AD5620_1250,
+	ID_AD5640_2500,
+	ID_AD5640_1250,
+	ID_AD5660_2500,
+	ID_AD5660_1250,
+	ID_AD5662,
+};
+
+static const struct ad5446_chip_info ad5446_spi_chip_info[] = {
+	[ID_AD5444] = {
+		.channel = AD5446_CHANNEL(12, 16, 2),
+		.write = ad5446_write,
+	},
+	[ID_AD5446] = {
+		.channel = AD5446_CHANNEL(14, 16, 0),
+		.write = ad5446_write,
+	},
+	[ID_AD5450] = {
+		.channel = AD5446_CHANNEL(8, 16, 6),
+		.write = ad5446_write,
+	},
+	[ID_AD5451] = {
+		.channel = AD5446_CHANNEL(10, 16, 4),
+		.write = ad5446_write,
+	},
+	[ID_AD5541A] = {
+		.channel = AD5446_CHANNEL(16, 16, 0),
+		.write = ad5446_write,
+	},
+	[ID_AD5512A] = {
+		.channel = AD5446_CHANNEL(12, 16, 4),
+		.write = ad5446_write,
+	},
+	[ID_AD5553] = {
+		.channel = AD5446_CHANNEL(14, 16, 0),
+		.write = ad5446_write,
+	},
+	[ID_AD5601] = {
+		.channel = AD5446_CHANNEL_POWERDOWN(8, 16, 6),
+		.write = ad5446_write,
+	},
+	[ID_AD5611] = {
+		.channel = AD5446_CHANNEL_POWERDOWN(10, 16, 4),
+		.write = ad5446_write,
+	},
+	[ID_AD5621] = {
+		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 2),
+		.write = ad5446_write,
+	},
+	[ID_AD5620_2500] = {
+		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 2),
+		.int_vref_mv = 2500,
+		.write = ad5446_write,
+	},
+	[ID_AD5620_1250] = {
+		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 2),
+		.int_vref_mv = 1250,
+		.write = ad5446_write,
+	},
+	[ID_AD5640_2500] = {
+		.channel = AD5446_CHANNEL_POWERDOWN(14, 16, 0),
+		.int_vref_mv = 2500,
+		.write = ad5446_write,
+	},
+	[ID_AD5640_1250] = {
+		.channel = AD5446_CHANNEL_POWERDOWN(14, 16, 0),
+		.int_vref_mv = 1250,
+		.write = ad5446_write,
+	},
+	[ID_AD5660_2500] = {
+		.channel = AD5446_CHANNEL_POWERDOWN(16, 16, 0),
+		.int_vref_mv = 2500,
+		.write = ad5660_write,
+	},
+	[ID_AD5660_1250] = {
+		.channel = AD5446_CHANNEL_POWERDOWN(16, 16, 0),
+		.int_vref_mv = 1250,
+		.write = ad5660_write,
+	},
+	[ID_AD5662] = {
+		.channel = AD5446_CHANNEL_POWERDOWN(16, 16, 0),
+		.write = ad5660_write,
+	},
+};
+
+static const struct spi_device_id ad5446_spi_ids[] = {
 	{"ad5444", ID_AD5444},
 	{"ad5446", ID_AD5446},
 	{"ad5450", ID_AD5450},
@@ -375,18 +408,157 @@ static const struct spi_device_id ad5446_id[] = {
 	{"ad5662", ID_AD5662},
 	{}
 };
-MODULE_DEVICE_TABLE(spi, ad5446_id);
+MODULE_DEVICE_TABLE(spi, ad5446_spi_ids);
+
+static int __devinit ad5446_spi_probe(struct spi_device *spi)
+{
+	const struct spi_device_id *id = spi_get_device_id(spi);
+
+	return ad5446_probe(&spi->dev, id->name,
+		&ad5446_spi_chip_info[id->driver_data]);
+}
 
-static struct spi_driver ad5446_driver = {
+static int __devexit ad5446_spi_remove(struct spi_device *spi)
+{
+	return ad5446_remove(&spi->dev);
+}
+
+static struct spi_driver ad5446_spi_driver = {
 	.driver = {
 		.name	= "ad5446",
 		.owner	= THIS_MODULE,
 	},
-	.probe		= ad5446_probe,
-	.remove		= __devexit_p(ad5446_remove),
-	.id_table	= ad5446_id,
+	.probe		= ad5446_spi_probe,
+	.remove		= __devexit_p(ad5446_spi_remove),
+	.id_table	= ad5446_spi_ids,
+};
+
+static int __init ad5446_spi_register_driver(void)
+{
+	return spi_register_driver(&ad5446_spi_driver);
+}
+
+static void ad5446_spi_unregister_driver(void)
+{
+	spi_unregister_driver(&ad5446_spi_driver);
+}
+
+#else
+
+static inline int ad5446_spi_register_driver(void) { return 0; }
+static inline void ad5446_spi_unregister_driver(void) { }
+
+#endif
+
+#if IS_ENABLED(CONFIG_I2C)
+
+static int ad5622_write(struct ad5446_state *st, unsigned val)
+{
+	struct i2c_client *client = to_i2c_client(st->dev);
+	__be16 data = cpu_to_be16(val);
+
+	return i2c_master_send(client, (char *)&data, sizeof(data));
+}
+
+/**
+ * ad5446_supported_i2c_device_ids:
+ * The AD5620/40/60 parts are available in different fixed internal reference
+ * voltage options. The actual part numbers may look differently
+ * (and a bit cryptic), however this style is used to make clear which
+ * parts are supported here.
+ */
+enum ad5446_supported_i2c_device_ids {
+	ID_AD5602,
+	ID_AD5612,
+	ID_AD5622,
+};
+
+static const struct ad5446_chip_info ad5446_i2c_chip_info[] = {
+	[ID_AD5602] = {
+		.channel = AD5446_CHANNEL_POWERDOWN(8, 16, 4),
+		.write = ad5622_write,
+	},
+	[ID_AD5612] = {
+		.channel = AD5446_CHANNEL_POWERDOWN(10, 16, 2),
+		.write = ad5622_write,
+	},
+	[ID_AD5622] = {
+		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 0),
+		.write = ad5622_write,
+	},
 };
-module_spi_driver(ad5446_driver);
+
+static int __devinit ad5446_i2c_probe(struct i2c_client *i2c,
+	const struct i2c_device_id *id)
+{
+	return ad5446_probe(&i2c->dev, id->name,
+		&ad5446_i2c_chip_info[id->driver_data]);
+}
+
+static int __devexit ad5446_i2c_remove(struct i2c_client *i2c)
+{
+	return ad5446_remove(&i2c->dev);
+}
+
+static const struct i2c_device_id ad5446_i2c_ids[] = {
+	{"ad5602", ID_AD5602},
+	{"ad5612", ID_AD5612},
+	{"ad5622", ID_AD5622},
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, ad5446_i2c_ids);
+
+static struct i2c_driver ad5446_i2c_driver = {
+	.driver = {
+		   .name = "ad5446",
+		   .owner = THIS_MODULE,
+	},
+	.probe = ad5446_i2c_probe,
+	.remove = __devexit_p(ad5446_i2c_remove),
+	.id_table = ad5446_i2c_ids,
+};
+
+static int __init ad5446_i2c_register_driver(void)
+{
+	return i2c_add_driver(&ad5446_i2c_driver);
+}
+
+static void __exit ad5446_i2c_unregister_driver(void)
+{
+	i2c_del_driver(&ad5446_i2c_driver);
+}
+
+#else
+
+static inline int ad5446_i2c_register_driver(void) { return 0; }
+static inline void ad5446_i2c_unregister_driver(void) { }
+
+#endif
+
+static int __init ad5446_init(void)
+{
+	int ret;
+
+	ret = ad5446_spi_register_driver();
+	if (ret)
+		return ret;
+
+	ret = ad5446_i2c_register_driver();
+	if (ret) {
+		ad5446_spi_unregister_driver();
+		return ret;
+	}
+
+	return 0;
+}
+module_init(ad5446_init);
+
+static void __exit ad5446_exit(void)
+{
+	ad5446_i2c_unregister_driver();
+	ad5446_spi_unregister_driver();
+}
+module_exit(ad5446_exit);
 
 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 MODULE_DESCRIPTION("Analog Devices AD5444/AD5446 DAC");
diff --git a/drivers/iio/dac/ad5446.h b/drivers/iio/dac/ad5446.h
index 2934269a56d..6b7a1766c10 100644
--- a/drivers/iio/dac/ad5446.h
+++ b/drivers/iio/dac/ad5446.h
@@ -38,7 +38,7 @@
  */
 
 struct ad5446_state {
-	struct spi_device		*spi;
+	struct device		*dev;
 	const struct ad5446_chip_info	*chip_info;
 	struct regulator		*reg;
 	unsigned short			vref_mv;
@@ -60,32 +60,5 @@ struct ad5446_chip_info {
 	int			(*write)(struct ad5446_state *st, unsigned val);
 };
 
-/**
- * ad5446_supported_device_ids:
- * The AD5620/40/60 parts are available in different fixed internal reference
- * voltage options. The actual part numbers may look differently
- * (and a bit cryptic), however this style is used to make clear which
- * parts are supported here.
- */
-
-enum ad5446_supported_device_ids {
-	ID_AD5444,
-	ID_AD5446,
-	ID_AD5450,
-	ID_AD5451,
-	ID_AD5541A,
-	ID_AD5512A,
-	ID_AD5553,
-	ID_AD5601,
-	ID_AD5611,
-	ID_AD5621,
-	ID_AD5620_2500,
-	ID_AD5620_1250,
-	ID_AD5640_2500,
-	ID_AD5640_1250,
-	ID_AD5660_2500,
-	ID_AD5660_1250,
-	ID_AD5662,
-};
 
 #endif /* IIO_DAC_AD5446_H_ */