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| author | Dirk Eibach <eibach@gdsys.de> | 2011-03-21 17:59:37 +0100 |
|---|---|---|
| committer | Jean Delvare <khali@endymion.delvare> | 2011-03-21 17:59:37 +0100 |
| commit | c0046867f34bb81ec3f237ebbc5241ae678b8379 (patch) | |
| tree | a5d9e95c3fcd09a53dac9ce88abb00f4bef4a4fc /Documentation/hwmon | |
| parent | fdf241a8ed93236915c70717a4b6dfb856274496 (diff) | |
| download | kernel_samsung_smdk4412-c0046867f34bb81ec3f237ebbc5241ae678b8379.zip kernel_samsung_smdk4412-c0046867f34bb81ec3f237ebbc5241ae678b8379.tar.gz kernel_samsung_smdk4412-c0046867f34bb81ec3f237ebbc5241ae678b8379.tar.bz2 | |
hwmon: (ads1015) Make gain and datarate configurable
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>
Diffstat (limited to 'Documentation/hwmon')
| -rw-r--r-- | Documentation/hwmon/ads1015 | 49 |
1 files changed, 27 insertions, 22 deletions
diff --git a/Documentation/hwmon/ads1015 b/Documentation/hwmon/ads1015 index 56ee797..f6fe9c2 100644 --- a/Documentation/hwmon/ads1015 +++ b/Documentation/hwmon/ads1015 @@ -19,7 +19,7 @@ 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: +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. @@ -29,39 +29,44 @@ 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. +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 as: - -struct ads1015_platform_data { - unsigned int exported_channels; -}; - -exported_channels is a bitmask that specifies which inputs should be exported. +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 = { - .exported_channels = (1 << 2) | (1 << 4) + .channel_data = { + [2] = { .enabled = true, .pga = 1, .data_rate = 0 }, + [4] = { .enabled = true, .pga = 4, .data_rate = 5 }, + } }; -In this case only in2_input and in4_input would be created. +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 ---------- -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. +Configuration is also possible via devicetree: +Documentation/devicetree/bindings/hwmon/ads1015.txt |