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Message-Id: <49eddbb75c677db62701e229330f0f5c35983130.1468626668.git.stillcompiling@gmail.com>
Date: Fri, 15 Jul 2016 17:18:22 -0700
From: Joshua Clayton <stillcompiling@...il.com>
To: Rob Herring <robh+dt@...nel.org>,
Mark Rutland <mark.rutland@....com>,
Shawn Guo <shawnguo@...nel.org>,
Sascha Hauer <kernel@...gutronix.de>,
Fabio Estevam <fabio.estevam@....com>,
Russell King <linux@...linux.org.uk>,
Jean Delvare <jdelvare@...e.com>,
Guenter Roeck <linux@...ck-us.net>, devicetree@...r.kernel.org,
linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
linux-hwmon@...r.kernel.org
Cc: Joshua Clayton <stillcompiling@...il.com>
Subject: [RCF 2/3] hwmon: Document bindings for ads1118 adc driver
ads1118 is a 4 input 16 bit adc with a buit-in temperature gauge
Signed-off-by: Joshua Clayton <stillcompiling@...il.com>
---
.../devicetree/bindings/hwmon/ads1118.txt | 81 ++++++++++++++++++++++
1 file changed, 81 insertions(+)
create mode 100644 Documentation/devicetree/bindings/hwmon/ads1118.txt
diff --git a/Documentation/devicetree/bindings/hwmon/ads1118.txt b/Documentation/devicetree/bindings/hwmon/ads1118.txt
new file mode 100644
index 0000000..41c66dc
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/ads1118.txt
@@ -0,0 +1,81 @@
+ADS1118 (SPI)
+
+The ADS1118 is 16-bit analog to digital converter with 4 inputs and a
+temperature sensor.
+The ADS1018 is a 12-bit version of the chip.
+
+The inputs can be single ended or differential pair combinations.
+
+Each channel, 0 - 4 may be configured as a single ended adc input.
+Channel 0 may be configured differentially with channel 1.
+Channels 0, 1, or 2 may be configured differentially with channel 3.
+
+To set up a differential pair, the lower channel should be have
+the ti,differential-endpoint property set to the higher channel in the pair.
+
+Each channel can be configured individually:
+ - fullscale voltage range values are +/- microvolts
+ 6144000, 4096000, 2048000, 1024000, 512000, or 256000
+
+ - data_rate in samples per second
+ - for the ads1018:
+ 128, 250, 490, 920, 1600, 2400, or 3300
+ - for the ads1118:
+ 8, 16, 32, 64, 128, 250, or 860
+
+The sensor contains an internal pullup register to keep the data output
+high when not in use. This may be disabled, but is enabled by default.
+
+1) The /ads1118 node
+
+ Required properties:
+
+ - compatible : must be "ti,ads1018" or "ti,ads1118"
+ - spi-cpha : spi phase set to 1 (spi polarity is 0)
+ - reg : the spi chipselect address
+ - #address-cells : must be <1>
+ - #size-cells : must be <0>
+
+ Optional properties:
+
+ - ti,tempsensor: enable the temperature sensor
+ - ti,pullup-disable: disable the internal pullup resistor
+
+ The node contains child nodes for each channel that the platform uses.
+
+2) channel nodes
+
+ Required properties:
+
+ - reg : the channel number (0, 1, 2, or 3)
+
+ Optional properties:
+
+ - ti,differential-endpoint: differential second endpoint.
+ - ti,fullscale: fullscale range in +/- microvolts
+ - ti,datarate : the converter data rate in samples / second
+
+ Example ADS1118 node:
+
+ ads1118@0 {
+ compatible = "ti,ads1118";
+ spi-max-frequency = <2450000>;
+ reg = <0>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ ti,tempsensor;
+ voltage0@0 {
+ reg = <0>;
+ ti,fullscale = <6144000>;
+ ti,datarate = <860>;
+ ti,differential-endpoint = <1>;
+ };
+ voltage1@3 {
+ reg = <3>;
+ ti,fullscale = <6144000>;
+ ti,datarate = <475>;
+ };
+ };
+
+For the above example, The temperature sensor is enabled as well as
+channels 0 and 1 in differential mode, and channel 3 single ended.
--
2.7.4
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