iio: adc: add exynos adc driver under iio framwork

This patch adds New driver to support:
1. Supports ADC IF found on EXYNOS4412/EXYNOS5250
   and future SoCs from Samsung
2. Add ADC driver under iio/adc framework
3. Also adds the Documentation for device tree bindings

Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 52 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/arm/samsung/exynos-adc.txt b/Documentation/devicetree/bindings/arm/samsung/exynos-adc.txt
new file mode 100644
index 0000000..f686378
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/samsung/exynos-adc.txt
@@ -0,0 +1,52 @@
+Samsung Exynos Analog to Digital Converter bindings
+
+This devicetree binding are for the new adc driver written fori
+Exynos4 and upward SoCs from Samsung.
+
+New driver handles the following
+1. Supports ADC IF found on EXYNOS4412/EXYNOS5250
+   and future SoCs from Samsung
+2. Add ADC driver under iio/adc framework
+3. Also adds the Documentation for device tree bindings
+
+Required properties:
+- compatible:		Must be "samsung,exynos-adc-v1"
+				for exynos4412/5250 controllers.
+			Must be "samsung,exynos-adc-v2" for
+				future controllers.
+- reg:			Contains ADC register address range (base address and
+			length).
+- interrupts: 		Contains the interrupt information for the timer. The
+			format is being dependent on which interrupt controller
+			the Samsung device uses.
+- #io-channel-cells = <1>; As ADC has multiple outputs
+
+Note: child nodes can be added for auto probing from device tree.
+
+Example: adding device info in dtsi file
+
+adc: adc@12D10000 {
+	compatible = "samsung,exynos-adc-v1";
+	reg = <0x12D10000 0x100>;
+	interrupts = <0 106 0>;
+	#io-channel-cells = <1>;
+	io-channel-ranges;
+};
+
+
+Example: Adding child nodes in dts file
+
+adc@12D10000 {
+
+	/* NTC thermistor is a hwmon device */
+	ncp15wb473@0 {
+		compatible = "ntc,ncp15wb473";
+		pullup-uV = <1800000>;
+		pullup-ohm = <47000>;
+		pulldown-ohm = <0>;
+		io-channels = <&adc 4>;
+	};
+};
+
+Note: Does not apply to ADC driver under arch/arm/plat-samsung/
+Note: The child node can be added under the adc node or seperately.