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Diffstat (limited to 'Documentation/hwmon/ads1015')
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diff --git a/Documentation/hwmon/ads1015 b/Documentation/hwmon/ads1015 new file mode 100644 index 00000000..f6fe9c20 --- /dev/null +++ b/Documentation/hwmon/ads1015 @@ -0,0 +1,72 @@ +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 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/i2c/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 |