iio: dac: ltc2664: Add driver for LTC2664 and LTC2672

LTC2664 4 channel, 12-/16-Bit Voltage Output SoftSpan DAC
LTC2672 5 channel, 12-/16-Bit Current Output Softspan DAC

Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Co-developed-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Kim Seer Paller <kimseer.paller@analog.com>
Link: https://patch.msgid.link/20240718051834.32270-7-kimseer.paller@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Author: kseerp

MAINTAINERS

@@ -12190,6 +12190,7 @@ S:	Supported
 W:	https://ez.analog.com/linux-software-drivers
 F:	Documentation/devicetree/bindings/iio/dac/adi,ltc2664.yaml
 F:	Documentation/devicetree/bindings/iio/dac/adi,ltc2672.yaml
+F:	drivers/iio/dac/ltc2664.c
 
 LTC2688 IIO DAC DRIVER
 M:	Nuno Sá <nuno.sa@analog.com>

drivers/iio/dac/Kconfig

@@ -345,6 +345,17 @@ config LTC2632
 	  To compile this driver as a module, choose M here: the
 	  module will be called ltc2632.
 
+config LTC2664
+	tristate "Analog Devices LTC2664 and LTC2672 DAC SPI driver"
+	depends on SPI
+	select REGMAP
+	help
+	  Say yes here to build support for Analog Devices
+	  LTC2664 and LTC2672 converters (DAC).
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ltc2664.
+
 config M62332
 	tristate "Mitsubishi M62332 DAC driver"
 	depends on I2C

drivers/iio/dac/Makefile

@@ -36,6 +36,7 @@ obj-$(CONFIG_DS4424) += ds4424.o
 obj-$(CONFIG_LPC18XX_DAC) += lpc18xx_dac.o
 obj-$(CONFIG_LTC1660) += ltc1660.o
 obj-$(CONFIG_LTC2632) += ltc2632.o
+obj-$(CONFIG_LTC2664) += ltc2664.o
 obj-$(CONFIG_LTC2688) += ltc2688.o
 obj-$(CONFIG_M62332) += m62332.o
 obj-$(CONFIG_MAX517) += max517.o