hwmon: Add support for Texas Instruments ADS1015

Signed-off-by: Dirk Eibach <eibach@gdsys.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

2 files changed, 96 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/hwmon/ads1015.txt b/Documentation/devicetree/bindings/hwmon/ads1015.txt
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+ADS1015 (I2C)
+
+This device is a 12-bit A-D converter with 4 inputs.
+
+The inputs can be used single ended or in certain differential combinations.
+
+For configuration all possible combinations are mapped to 8 channels:
+0: Voltage over AIN0 and AIN1.
+1: Voltage over AIN0 and AIN3.
+2: Voltage over AIN1 and AIN3.
+3: Voltage over AIN2 and AIN3.
+4: Voltage over AIN0 and GND.
+5: Voltage over AIN1 and GND.
+6: Voltage over AIN2 and GND.
+7: Voltage over AIN3 and GND.
+
+Optional properties:
+
+ - exported-channels : exported_channels is a bitmask that specifies which
+		       channels should be accessable by the user.
+
+Example:
+ads1015@49 {
+	compatible = "ti,ads1015";
+	reg = <0x49>;
+	exported-channels = <0x14>;
+};
+
+In this example only channel 2 and 4 would be accessable by the user.
diff --git a/Documentation/hwmon/ads1015 b/Documentation/hwmon/ads1015
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+Kernel driver ads1015
+=====================
+
+Supported chips:
+  * Texas Instruments ADS1015
+    Prefix: 'ads1015'
+    Datasheet: Publicly available at the Texas Instruments website :
+               http://focus.ti.com/lit/ds/symlink/ads1015.pdf
+
+Authors:
+        Dirk Eibach, Guntermann & Drunck GmbH <eibach@gdsys.de>
+
+Description
+-----------
+
+This driver implements support for the Texas Instruments ADS1015.
+
+This device is a 12-bit A-D converter with 4 inputs.
+
+The inputs can be used single ended or in certain differential combinations.
+
+The inputs can be exported to 8 sysfs input files in0_input - in7_input:
+in0: Voltage over AIN0 and AIN1.
+in1: Voltage over AIN0 and AIN3.
+in2: Voltage over AIN1 and AIN3.
+in3: Voltage over AIN2 and AIN3.
+in4: Voltage over AIN0 and GND.
+in5: Voltage over AIN1 and GND.
+in6: Voltage over AIN2 and GND.
+in7: Voltage over AIN3 and GND.
+
+Which inputs are exported can be configured using platform data or devicetree.
+
+By default all inputs are exported.
+
+Platform Data
+-------------
+
+In linux/i2c/ads1015.h platform data is defined as:
+
+struct ads1015_platform_data {
+	unsigned int exported_channels;
+};
+
+exported_channels is a bitmask that specifies which inputs should be exported.
+
+Example:
+struct ads1015_platform_data data = {
+	.exported_channels = (1 << 2) | (1 << 4)
+};
+
+In this case only in2_input and in4_input would be created.
+
+Devicetree
+----------
+
+The ads1015 node may have an "exported-channels" property.
+exported_channels is a bitmask that specifies which inputs should be exported.
+
+Example:
+ads1015@49 {
+	compatible = "ti,ads1015";
+	reg = <0x49>;
+	exported-channels = < 0x14 >;
+};
+
+In this case only in2_input and in4_input would be created.