iio: dac: Add support for the AD5592R/AD5593R ADCs/DACs

This patch adds support for the AD5592R (spi) and AD5593R (i2c)
ADC/DAC/GPIO devices.

Signed-off-by: Paul Cercueil <paul.cercueil@analog.com>
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 155 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/iio/dac/ad5592r.txt b/Documentation/devicetree/bindings/iio/dac/ad5592r.txt
new file mode 100644
index 000000000000..989f96f31c66
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/dac/ad5592r.txt
@@ -0,0 +1,155 @@
+Analog Devices AD5592R/AD5593R DAC/ADC device driver
+
+Required properties for the AD5592R:
+	- compatible: Must be "adi,ad5592r"
+	- reg: SPI chip select number for the device
+	- spi-max-frequency: Max SPI frequency to use (< 30000000)
+	- spi-cpol: The AD5592R requires inverse clock polarity (CPOL) mode
+
+Required properties for the AD5593R:
+	- compatible: Must be "adi,ad5593r"
+	- reg: I2C address of the device
+
+Required properties for all supported chips:
+	- #address-cells: Should be 1.
+	- #size-cells: Should be 0.
+	- channel nodes:
+	  Each child node represents one channel and has the following
+	  Required properties:
+		* reg: Pin on which this channel is connected to.
+		* adi,mode: Mode or function of this channel.
+			    Macros specifying the valid values
+			    can be found in <dt-bindings/iio/adi,ad5592r.h>.
+
+			    The following values are currently supported:
+				* CH_MODE_UNUSED (the pin is unused)
+				* CH_MODE_ADC (the pin is ADC input)
+				* CH_MODE_DAC (the pin is DAC output)
+				* CH_MODE_DAC_AND_ADC (the pin is DAC output
+					but can be monitored by an ADC, since
+					there is no disadvantage this
+					this should be considered as the
+					preferred DAC mode)
+				* CH_MODE_GPIO (the pin is registered
+					with GPIOLIB)
+	 Optional properties:
+		* adi,off-state: State of this channel when unused or the
+				 device gets removed. Macros specifying the
+				 valid values can be found in
+				 <dt-bindings/iio/adi,ad5592r.h>.
+
+				* CH_OFFSTATE_PULLDOWN (the pin is pulled down)
+				* CH_OFFSTATE_OUT_LOW  (the pin is output low)
+				* CH_OFFSTATE_OUT_HIGH (the pin is output high)
+				* CH_OFFSTATE_OUT_TRISTATE (the pin is
+					tristated output)
+
+
+Optional properties:
+	- vref-supply: Phandle to the external reference voltage supply. This should
+	  only be set if there is an external reference voltage connected to the VREF
+	  pin. If the property is not set the internal 2.5V reference is used.
+	- reset-gpios : GPIO spec for the RESET pin. If specified, it will be
+	  asserted during driver probe.
+	- gpio-controller: Marks the device node as a GPIO controller.
+	- #gpio-cells: Should be 2. The first cell is the GPIO number and the second
+	  cell specifies GPIO flags, as defined in <dt-bindings/gpio/gpio.h>.
+
+AD5592R Example:
+
+	#include <dt-bindings/iio/adi,ad5592r.h>
+
+	vref: regulator-vref {
+		compatible = "regulator-fixed";
+		regulator-name = "vref-ad559x";
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+		regulator-always-on;
+	};
+
+	ad5592r@0 {
+		#size-cells = <0>;
+		#address-cells = <1>;
+		#gpio-cells = <2>;
+		compatible = "adi,ad5592r";
+		reg = <0>;
+
+		spi-max-frequency = <1000000>;
+		spi-cpol;
+
+		vref-supply = <&vref>; /* optional */
+		reset-gpios = <&gpio0 86 0>;  /* optional */
+		gpio-controller;
+
+		channel@0 {
+			reg = <0>;
+			adi,mode = <CH_MODE_DAC>;
+		};
+		channel@1 {
+			reg = <1>;
+			adi,mode = <CH_MODE_ADC>;
+		};
+		channel@2 {
+			reg = <2>;
+			adi,mode = <CH_MODE_DAC_AND_ADC>;
+		};
+		channel@3 {
+			reg = <3>;
+			adi,mode = <CH_MODE_DAC_AND_ADC>;
+			adi,off-state = <CH_OFFSTATE_PULLDOWN>;
+		};
+		channel@4 {
+			reg = <4>;
+			adi,mode = <CH_MODE_UNUSED>;
+			adi,off-state = <CH_OFFSTATE_PULLDOWN>;
+		};
+		channel@5 {
+			reg = <5>;
+			adi,mode = <CH_MODE_GPIO>;
+			adi,off-state = <CH_OFFSTATE_PULLDOWN>;
+		};
+		channel@6 {
+			reg = <6>;
+			adi,mode = <CH_MODE_GPIO>;
+			adi,off-state = <CH_OFFSTATE_PULLDOWN>;
+		};
+		channel@7 {
+			reg = <7>;
+			adi,mode = <CH_MODE_GPIO>;
+			adi,off-state = <CH_OFFSTATE_PULLDOWN>;
+		};
+	};
+
+AD5593R Example:
+
+	#include <dt-bindings/iio/adi,ad5592r.h>
+
+	ad5593r@10 {
+		#size-cells = <0>;
+		#address-cells = <1>;
+		#gpio-cells = <2>;
+		compatible = "adi,ad5593r";
+		reg = <0x10>;
+		gpio-controller;
+
+		channel@0 {
+			reg = <0>;
+			adi,mode = <CH_MODE_DAC>;
+			adi,off-state = <CH_OFFSTATE_PULLDOWN>;
+		};
+		channel@1 {
+			reg = <1>;
+			adi,mode = <CH_MODE_ADC>;
+			adi,off-state = <CH_OFFSTATE_PULLDOWN>;
+		};
+		channel@2 {
+			reg = <2>;
+			adi,mode = <CH_MODE_DAC_AND_ADC>;
+			adi,off-state = <CH_OFFSTATE_PULLDOWN>;
+		};
+		channel@6 {
+			reg = <6>;
+			adi,mode = <CH_MODE_GPIO>;
+			adi,off-state = <CH_OFFSTATE_PULLDOWN>;
+		};
+	};