hwmon: (ntc_thermistor) Add DT with IIO support to NTC thermistor driver

This patch adds DT support to NTC driver to parse the
platform data.

Also adds the support to work as an iio device client.

During the probe ntc driver gets the respective channels of ADC
and uses iio_raw_read calls to get the ADC converted value.

Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
[Guenter Roeck: fixed Kconfig dependencies; use ERR_CAST]
Tested-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

1 files changed, 29 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/hwmon/ntc_thermistor.txt b/Documentation/devicetree/bindings/hwmon/ntc_thermistor.txt
new file mode 100644
index 000000000000..c6f66674f19c
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/ntc_thermistor.txt
@@ -0,0 +1,29 @@
+NTC Thermistor hwmon sensors
+-------------------------------
+
+Requires node properties:
+- "compatible" value : one of
+	"ntc,ncp15wb473"
+	"ntc,ncp18wb473"
+	"ntc,ncp21wb473"
+	"ntc,ncp03wb473"
+	"ntc,ncp15wl333"
+- "pullup-uv"	Pull up voltage in micro volts
+- "pullup-ohm"	Pull up resistor value in ohms
+- "pulldown-ohm" Pull down resistor value in ohms
+- "connected-positive" Always ON, If not specified.
+		Status change is possible.
+- "io-channels"	Channel node of ADC to be used for
+		conversion.
+
+Read more about iio bindings at
+	Documentation/devicetree/bindings/iio/iio-bindings.txt
+
+Example:
+	ncp15wb473@0 {
+		compatible = "ntc,ncp15wb473";
+		pullup-uv = <1800000>;
+		pullup-ohm = <47000>;
+		pulldown-ohm = <0>;
+		io-channels = <&adc 3>;
+	};