iio: dac: ad5686: add support for AD5338R

The AD5338R is a 10-bit DAC with 2 outputs and an internal 2.5V
reference (enabled by default). The register configuration is nearly
identical to the AD5696R DAC that's already supported by this driver,
with the channel selection bits being the only thing different.

Signed-off-by: Michael Auchter <michael.auchter@ni.com>
Link: https://lore.kernel.org/r/20200924195215.49443-1-michael.auchter@ni.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/dac/Kconfig

@@ -141,9 +141,10 @@ config AD5696_I2C
 	depends on I2C
 	select AD5686
 	help
-	  Say yes here to build support for Analog Devices AD5671R, AD5675R,
-	  AD5694, AD5694R, AD5695R, AD5696, AD5696R Voltage Output Digital to
-	  Analog Converter.
+	  Say yes here to build support for Analog Devices AD5311R, AD5338R,
+	  AD5671R, AD5675R, AD5691R, AD5692R, AD5693, AD5693R, AD5694, AD5694R,
+	  AD5695R, AD5696, and AD5696R Digital to Analog converters.
+
 	  To compile this driver as a module, choose M here: the module will be
 	  called ad5696.
 

drivers/iio/dac/ad5686.c

@@ -210,6 +210,12 @@ static const struct iio_chan_spec name[] = {			\
 		AD5868_CHANNEL(0, 0, bits, _shift),		\
 }
 
+#define DECLARE_AD5338_CHANNELS(name, bits, _shift)		\
+static const struct iio_chan_spec name[] = {			\
+		AD5868_CHANNEL(0, 1, bits, _shift),		\
+		AD5868_CHANNEL(1, 8, bits, _shift),		\
+}
+
 #define DECLARE_AD5686_CHANNELS(name, bits, _shift)		\
 static const struct iio_chan_spec name[] = {			\
 		AD5868_CHANNEL(0, 1, bits, _shift),		\
@@ -252,6 +258,7 @@ static const struct iio_chan_spec name[] = {			\
 
 DECLARE_AD5693_CHANNELS(ad5310r_channels, 10, 2);
 DECLARE_AD5693_CHANNELS(ad5311r_channels, 10, 6);
+DECLARE_AD5338_CHANNELS(ad5338r_channels, 10, 6);
 DECLARE_AD5676_CHANNELS(ad5672_channels, 12, 4);
 DECLARE_AD5679_CHANNELS(ad5674r_channels, 12, 4);
 DECLARE_AD5676_CHANNELS(ad5676_channels, 16, 0);
@@ -276,6 +283,12 @@ static const struct ad5686_chip_info ad5686_chip_info_tbl[] = {
 		.num_channels = 1,
 		.regmap_type = AD5693_REGMAP,
 	},
+	[ID_AD5338R] = {
+		.channels = ad5338r_channels,
+		.int_vref_mv = 2500,
+		.num_channels = 2,
+		.regmap_type = AD5686_REGMAP,
+	},
 	[ID_AD5671R] = {
 		.channels = ad5672_channels,
 		.int_vref_mv = 2500,

drivers/iio/dac/ad5686.h

@@ -52,6 +52,7 @@
 enum ad5686_supported_device_ids {
 	ID_AD5310R,
 	ID_AD5311R,
+	ID_AD5338R,
 	ID_AD5671R,
 	ID_AD5672R,
 	ID_AD5674R,

drivers/iio/dac/ad5696-i2c.c

@@ -72,6 +72,7 @@ static int ad5686_i2c_remove(struct i2c_client *i2c)
 
 static const struct i2c_device_id ad5686_i2c_id[] = {
 	{"ad5311r", ID_AD5311R},
+	{"ad5338r", ID_AD5338R},
 	{"ad5671r", ID_AD5671R},
 	{"ad5675r", ID_AD5675R},
 	{"ad5691r", ID_AD5691R},