c0046867f3
Configuration for ads1015 gain and datarate is possible via devicetree or platform data. This is a followup patch to previous ads1015 patches on Jean Delvares tree. Signed-off-by: Dirk Eibach <eibach@gdsys.de> Signed-off-by: Jean Delvare <khali@linux-fr.org>
72 lines
1.8 KiB
Text
72 lines
1.8 KiB
Text
Kernel driver ads1015
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=====================
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Supported chips:
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* Texas Instruments ADS1015
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Prefix: 'ads1015'
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Datasheet: Publicly available at the Texas Instruments website :
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http://focus.ti.com/lit/ds/symlink/ads1015.pdf
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Authors:
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Dirk Eibach, Guntermann & Drunck GmbH <eibach@gdsys.de>
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Description
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-----------
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This driver implements support for the Texas Instruments ADS1015.
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This device is a 12-bit A-D converter with 4 inputs.
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The inputs can be used single ended or in certain differential combinations.
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The inputs can be made available by 8 sysfs input files in0_input - in7_input:
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in0: Voltage over AIN0 and AIN1.
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in1: Voltage over AIN0 and AIN3.
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in2: Voltage over AIN1 and AIN3.
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in3: Voltage over AIN2 and AIN3.
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in4: Voltage over AIN0 and GND.
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in5: Voltage over AIN1 and GND.
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in6: Voltage over AIN2 and GND.
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in7: Voltage over AIN3 and GND.
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Which inputs are available can be configured using platform data or devicetree.
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By default all inputs are exported.
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Platform Data
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-------------
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In linux/i2c/ads1015.h platform data is defined, channel_data contains
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configuration data for the used input combinations:
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- pga is the programmable gain amplifier (values are full scale)
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0: +/- 6.144 V
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1: +/- 4.096 V
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2: +/- 2.048 V
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3: +/- 1.024 V
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4: +/- 0.512 V
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5: +/- 0.256 V
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- data_rate in samples per second
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0: 128
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1: 250
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2: 490
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3: 920
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4: 1600
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5: 2400
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6: 3300
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Example:
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struct ads1015_platform_data data = {
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.channel_data = {
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[2] = { .enabled = true, .pga = 1, .data_rate = 0 },
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[4] = { .enabled = true, .pga = 4, .data_rate = 5 },
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}
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};
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In this case only in2_input (FS +/- 4.096 V, 128 SPS) and in4_input
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(FS +/- 0.512 V, 2400 SPS) would be created.
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Devicetree
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----------
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Configuration is also possible via devicetree:
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Documentation/devicetree/bindings/hwmon/ads1015.txt
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