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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
* Texas Instruments ADS1115
Prefix: 'ads1115'
Datasheet: Publicly available at the Texas Instruments website:
http://focus.ti.com/lit/ds/symlink/ads1115.pdf
Authors:
Dirk Eibach, Guntermann & Drunck GmbH <eibach@gdsys.de>
Description
-----------
This driver implements support for the Texas Instruments ADS1015/ADS1115.
This device is a 12/16-bit A-D converter with 4 inputs.
The inputs can be used single ended or in certain differential combinations.
The inputs can be made available by 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 available can be configured using platform data or devicetree.
By default all inputs are exported.
Platform Data
-------------
In linux/platform_data/ads1015.h platform data is defined, channel_data contains
configuration data for the used input combinations:
- pga is the programmable gain amplifier (values are full scale)
- 0: +/- 6.144 V
- 1: +/- 4.096 V
- 2: +/- 2.048 V
- 3: +/- 1.024 V
- 4: +/- 0.512 V
- 5: +/- 0.256 V
- data_rate in samples per second
- 0: 128
- 1: 250
- 2: 490
- 3: 920
- 4: 1600
- 5: 2400
- 6: 3300
Example::
struct ads1015_platform_data data = {
.channel_data = {
[2] = { .enabled = true, .pga = 1, .data_rate = 0 },
[4] = { .enabled = true, .pga = 4, .data_rate = 5 },
}
};
In this case only in2_input (FS +/- 4.096 V, 128 SPS) and in4_input
(FS +/- 0.512 V, 2400 SPS) would be created.
Devicetree
----------
Configuration is also possible via devicetree:
Documentation/devicetree/bindings/hwmon/ads1015.txt
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