68 lines
1.7 KiB
Text
68 lines
1.7 KiB
Text
|
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.
|