projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| df922703 ML |
1 | Kernel driver ltc2990 |
| 2 | ===================== | |
| 3 | ||
| 4 | Supported chips: | |
| 5 | * Linear Technology LTC2990 | |
| 6 | Prefix: 'ltc2990' | |
| 7 | Addresses scanned: - | |
| 8 | Datasheet: http://www.linear.com/product/ltc2990 | |
| 9 | ||
| 10 | Author: Mike Looijmans <mike.looijmans@topic.nl> | |
| 5d9ca430 | 11 | Tom Levens <tom.levens@cern.ch> |
| df922703 ML |
12 | |
| 13 | ||
| 14 | Description | |
| 15 | ----------- | |
| 16 | ||
| 17 | LTC2990 is a Quad I2C Voltage, Current and Temperature Monitor. | |
| 18 | The chip's inputs can measure 4 voltages, or two inputs together (1+2 and 3+4) | |
| 19 | can be combined to measure a differential voltage, which is typically used to | |
| 5d9ca430 TL |
20 | measure current through a series resistor, or a temperature with an external |
| 21 | diode. | |
| df922703 ML |
22 | |
| 23 | ||
| 24 | Usage Notes | |
| 25 | ----------- | |
| 26 | ||
| 27 | This driver does not probe for PMBus devices. You will have to instantiate | |
| 28 | devices explicitly. | |
| 29 | ||
| 30 | ||
| 31 | Sysfs attributes | |
| 32 | ---------------- | |
| 33 | ||
| 5d9ca430 TL |
34 | in0_input Voltage at Vcc pin in millivolt (range 2.5V to 5V) |
| 35 | temp1_input Internal chip temperature in millidegrees Celcius | |
| 36 | ||
| 37 | A subset of the following attributes are visible, depending on the measurement | |
| 38 | mode of the chip. | |
| 39 | ||
| 40 | in[1-4]_input Voltage at V[1-4] pin in millivolt | |
| 41 | temp2_input External temperature sensor TR1 in millidegrees Celcius | |
| 42 | temp3_input External temperature sensor TR2 in millidegrees Celcius | |
| 43 | curr1_input Current in mA across V1-V2 assuming a 1mOhm sense resistor | |
| 44 | curr2_input Current in mA across V3-V4 assuming a 1mOhm sense resistor | |
| 45 | ||
| df922703 ML |
46 | The "curr*_input" measurements actually report the voltage drop across the |
| 47 | input pins in microvolts. This is equivalent to the current through a 1mOhm | |
| 48 | sense resistor. Divide the reported value by the actual sense resistor value | |
| 49 | in mOhm to get the actual value. |