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>
diff --git a/drivers/iio/dac/ad5446.c b/drivers/iio/dac/ad5446.c
index 2ca5059..241665b 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 @@
 	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,
@@ -136,9 +120,194 @@
 	_AD5446_CHANNEL(bits, storage, shift, NULL)
 
 #define AD5446_CHANNEL_POWERDOWN(bits, storage, shift) \
-	_AD5446_CHANNEL(bits, storage, shift, ad5064_ext_info_powerdown)
+	_AD5446_CHANNEL(bits, storage, shift, ad5446_ext_info_powerdown)
 
-static const struct ad5446_chip_info ad5446_chip_info_tbl[] = {
+static int ad5446_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val,
+			   int *val2,
+			   long m)
+{
+	struct ad5446_state *st = iio_priv(indio_dev);
+	unsigned long scale_uv;
+
+	switch (m) {
+	case IIO_CHAN_INFO_RAW:
+		*val = st->cached_val;
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		scale_uv = (st->vref_mv * 1000) >> chan->scan_type.realbits;
+		*val =  scale_uv / 1000;
+		*val2 = (scale_uv % 1000) * 1000;
+		return IIO_VAL_INT_PLUS_MICRO;
+
+	}
+	return -EINVAL;
+}
+
+static int ad5446_write_raw(struct iio_dev *indio_dev,
+			       struct iio_chan_spec const *chan,
+			       int val,
+			       int val2,
+			       long mask)
+{
+	struct ad5446_state *st = iio_priv(indio_dev);
+	int ret = 0;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		if (val >= (1 << chan->scan_type.realbits) || val < 0)
+			return -EINVAL;
+
+		val <<= chan->scan_type.shift;
+		mutex_lock(&indio_dev->mlock);
+		st->cached_val = val;
+		if (!st->pwr_down)
+			ret = st->chip_info->write(st, val);
+		mutex_unlock(&indio_dev->mlock);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static const struct iio_info ad5446_info = {
+	.read_raw = ad5446_read_raw,
+	.write_raw = ad5446_write_raw,
+	.driver_module = THIS_MODULE,
+};
+
+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(dev, "vcc");
+	if (!IS_ERR(reg)) {
+		ret = regulator_enable(reg);
+		if (ret)
+			goto error_put_reg;
+
+		voltage_uv = regulator_get_voltage(reg);
+	}
+
+	indio_dev = iio_device_alloc(sizeof(*st));
+	if (indio_dev == NULL) {
+		ret = -ENOMEM;
+		goto error_disable_reg;
+	}
+	st = iio_priv(indio_dev);
+	st->chip_info = chip_info;
+
+	dev_set_drvdata(dev, indio_dev);
+	st->reg = reg;
+	st->dev = dev;
+
+	/* 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;
+	indio_dev->num_channels = 1;
+
+	st->pwr_down_mode = MODE_PWRDWN_1k;
+
+	if (st->chip_info->int_vref_mv)
+		st->vref_mv = st->chip_info->int_vref_mv;
+	else if (voltage_uv)
+		st->vref_mv = voltage_uv / 1000;
+	else
+		dev_warn(dev, "reference voltage unspecified\n");
+
+	ret = iio_device_register(indio_dev);
+	if (ret)
+		goto error_free_device;
+
+	return 0;
+
+error_free_device:
+	iio_device_free(indio_dev);
+error_disable_reg:
+	if (!IS_ERR(reg))
+		regulator_disable(reg);
+error_put_reg:
+	if (!IS_ERR(reg))
+		regulator_put(reg);
+
+	return ret;
+}
+
+static int ad5446_remove(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct ad5446_state *st = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+	if (!IS_ERR(st->reg)) {
+		regulator_disable(st->reg);
+		regulator_put(st->reg);
+	}
+	iio_device_free(indio_dev);
+
+	return 0;
+}
+
+#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,
@@ -215,143 +384,7 @@
 	},
 };
 
-static int ad5446_read_raw(struct iio_dev *indio_dev,
-			   struct iio_chan_spec const *chan,
-			   int *val,
-			   int *val2,
-			   long m)
-{
-	struct ad5446_state *st = iio_priv(indio_dev);
-	unsigned long scale_uv;
-
-	switch (m) {
-	case IIO_CHAN_INFO_RAW:
-		*val = st->cached_val;
-		return IIO_VAL_INT;
-	case IIO_CHAN_INFO_SCALE:
-		scale_uv = (st->vref_mv * 1000) >> chan->scan_type.realbits;
-		*val =  scale_uv / 1000;
-		*val2 = (scale_uv % 1000) * 1000;
-		return IIO_VAL_INT_PLUS_MICRO;
-
-	}
-	return -EINVAL;
-}
-
-static int ad5446_write_raw(struct iio_dev *indio_dev,
-			       struct iio_chan_spec const *chan,
-			       int val,
-			       int val2,
-			       long mask)
-{
-	struct ad5446_state *st = iio_priv(indio_dev);
-	int ret = 0;
-
-	switch (mask) {
-	case IIO_CHAN_INFO_RAW:
-		if (val >= (1 << chan->scan_type.realbits) || val < 0)
-			return -EINVAL;
-
-		val <<= chan->scan_type.shift;
-		mutex_lock(&indio_dev->mlock);
-		st->cached_val = val;
-		if (!st->pwr_down)
-			ret = st->chip_info->write(st, val);
-		mutex_unlock(&indio_dev->mlock);
-		break;
-	default:
-		ret = -EINVAL;
-	}
-
-	return ret;
-}
-
-static const struct iio_info ad5446_info = {
-	.read_raw = ad5446_read_raw,
-	.write_raw = ad5446_write_raw,
-	.driver_module = THIS_MODULE,
-};
-
-static int __devinit ad5446_probe(struct spi_device *spi)
-{
-	struct ad5446_state *st;
-	struct iio_dev *indio_dev;
-	struct regulator *reg;
-	int ret, voltage_uv = 0;
-
-	reg = regulator_get(&spi->dev, "vcc");
-	if (!IS_ERR(reg)) {
-		ret = regulator_enable(reg);
-		if (ret)
-			goto error_put_reg;
-
-		voltage_uv = regulator_get_voltage(reg);
-	}
-
-	indio_dev = iio_device_alloc(sizeof(*st));
-	if (indio_dev == NULL) {
-		ret = -ENOMEM;
-		goto error_disable_reg;
-	}
-	st = iio_priv(indio_dev);
-	st->chip_info =
-		&ad5446_chip_info_tbl[spi_get_device_id(spi)->driver_data];
-
-	spi_set_drvdata(spi, indio_dev);
-	st->reg = reg;
-	st->spi = spi;
-
-	/* 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;
-	indio_dev->info = &ad5446_info;
-	indio_dev->modes = INDIO_DIRECT_MODE;
-	indio_dev->channels = &st->chip_info->channel;
-	indio_dev->num_channels = 1;
-
-	st->pwr_down_mode = MODE_PWRDWN_1k;
-
-	if (st->chip_info->int_vref_mv)
-		st->vref_mv = st->chip_info->int_vref_mv;
-	else if (voltage_uv)
-		st->vref_mv = voltage_uv / 1000;
-	else
-		dev_warn(&spi->dev, "reference voltage unspecified\n");
-
-	ret = iio_device_register(indio_dev);
-	if (ret)
-		goto error_free_device;
-
-	return 0;
-
-error_free_device:
-	iio_device_free(indio_dev);
-error_disable_reg:
-	if (!IS_ERR(reg))
-		regulator_disable(reg);
-error_put_reg:
-	if (!IS_ERR(reg))
-		regulator_put(reg);
-
-	return ret;
-}
-
-static int ad5446_remove(struct spi_device *spi)
-{
-	struct iio_dev *indio_dev = spi_get_drvdata(spi);
-	struct ad5446_state *st = iio_priv(indio_dev);
-
-	iio_device_unregister(indio_dev);
-	if (!IS_ERR(st->reg)) {
-		regulator_disable(st->reg);
-		regulator_put(st->reg);
-	}
-	iio_device_free(indio_dev);
-
-	return 0;
-}
-
-static const struct spi_device_id ad5446_id[] = {
+static const struct spi_device_id ad5446_spi_ids[] = {
 	{"ad5444", ID_AD5444},
 	{"ad5446", ID_AD5446},
 	{"ad5450", ID_AD5450},
@@ -375,18 +408,157 @@
 	{"ad5662", ID_AD5662},
 	{}
 };
-MODULE_DEVICE_TABLE(spi, ad5446_id);
+MODULE_DEVICE_TABLE(spi, ad5446_spi_ids);
 
-static struct spi_driver ad5446_driver = {
+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 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,
 };
-module_spi_driver(ad5446_driver);
+
+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,
+	},
+};
+
+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");