projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| df922703 ML |
1 | Kernel driver ltc2990 |
| 2 | ===================== | |
| 3 | ||
| b04f2f7d | 4 | |
| df922703 | 5 | Supported chips: |
| b04f2f7d | 6 | |
| df922703 | 7 | * Linear Technology LTC2990 |
| b04f2f7d | 8 | |
| df922703 | 9 | Prefix: 'ltc2990' |
| b04f2f7d | 10 | |
| df922703 | 11 | Addresses scanned: - |
| b04f2f7d | 12 | |
| df922703 ML |
13 | Datasheet: http://www.linear.com/product/ltc2990 |
| 14 | ||
| b04f2f7d MCC |
15 | |
| 16 | ||
| 17 | Author: | |
| 18 | ||
| 19 | - Mike Looijmans <mike.looijmans@topic.nl> | |
| 20 | - Tom Levens <tom.levens@cern.ch> | |
| df922703 ML |
21 | |
| 22 | ||
| 23 | Description | |
| 24 | ----------- | |
| 25 | ||
| 26 | LTC2990 is a Quad I2C Voltage, Current and Temperature Monitor. | |
| 27 | The chip's inputs can measure 4 voltages, or two inputs together (1+2 and 3+4) | |
| 28 | can be combined to measure a differential voltage, which is typically used to | |
| 5d9ca430 TL |
29 | measure current through a series resistor, or a temperature with an external |
| 30 | diode. | |
| df922703 ML |
31 | |
| 32 | ||
| 33 | Usage Notes | |
| 34 | ----------- | |
| 35 | ||
| 36 | This driver does not probe for PMBus devices. You will have to instantiate | |
| 37 | devices explicitly. | |
| 38 | ||
| 39 | ||
| 40 | Sysfs attributes | |
| 41 | ---------------- | |
| 42 | ||
| b04f2f7d | 43 | ============= ================================================== |
| 5d9ca430 | 44 | in0_input Voltage at Vcc pin in millivolt (range 2.5V to 5V) |
| b04f2f7d MCC |
45 | temp1_input Internal chip temperature in millidegrees Celsius |
| 46 | ============= ================================================== | |
| 5d9ca430 TL |
47 | |
| 48 | A subset of the following attributes are visible, depending on the measurement | |
| 49 | mode of the chip. | |
| 50 | ||
| b04f2f7d | 51 | ============= ========================================================== |
| 5d9ca430 | 52 | in[1-4]_input Voltage at V[1-4] pin in millivolt |
| b04f2f7d MCC |
53 | temp2_input External temperature sensor TR1 in millidegrees Celsius |
| 54 | temp3_input External temperature sensor TR2 in millidegrees Celsius | |
| 5d9ca430 TL |
55 | curr1_input Current in mA across V1-V2 assuming a 1mOhm sense resistor |
| 56 | curr2_input Current in mA across V3-V4 assuming a 1mOhm sense resistor | |
| b04f2f7d | 57 | ============= ========================================================== |
| 5d9ca430 | 58 | |
| df922703 ML |
59 | The "curr*_input" measurements actually report the voltage drop across the |
| 60 | input pins in microvolts. This is equivalent to the current through a 1mOhm | |
| 61 | sense resistor. Divide the reported value by the actual sense resistor value | |
| 62 | in mOhm to get the actual value. |