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>

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.

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_ */