projects / mirror_ubuntu-kernels.git / blame
| Commit | Line | Data |
|---|---|---|
| 9df7305b SG |
1 | Kernel driver emc2103 |
| 2 | ====================== | |
| 3 | ||
| 4 | Supported chips: | |
| 92e395d7 | 5 | |
| 9df7305b | 6 | * SMSC EMC2103 |
| 92e395d7 | 7 | |
| 9df7305b | 8 | Addresses scanned: I2C 0x2e |
| 92e395d7 | 9 | |
| 9df7305b | 10 | Prefix: 'emc2103' |
| 92e395d7 | 11 | |
| 9df7305b SG |
12 | Datasheet: Not public |
| 13 | ||
| 14 | Authors: | |
| 92e395d7 | 15 | Steve Glendinning <steve.glendinning@smsc.com> |
| 9df7305b SG |
16 | |
| 17 | Description | |
| 18 | ----------- | |
| 19 | ||
| 20 | The Standard Microsystems Corporation (SMSC) EMC2103 chips | |
| 21 | contain up to 4 temperature sensors and a single fan controller. | |
| 22 | ||
| 23 | Fan rotation speeds are reported in RPM (rotations per minute). An alarm is | |
| 24 | triggered if the rotation speed has dropped below a programmable limit. Fan | |
| 25 | readings can be divided by a programmable divider (1, 2, 4 or 8) to give | |
| 26 | the readings more range or accuracy. Not all RPM values can accurately be | |
| 27 | represented, so some rounding is done. With a divider of 1, the lowest | |
| 28 | representable value is 480 RPM. | |
| 29 | ||
| 30 | This driver supports RPM based control, to use this a fan target | |
| 31 | should be written to fan1_target and pwm1_enable should be set to 3. | |
| 32 | ||
| 33 | The 2103-2 and 2103-4 variants have a third temperature sensor, which can | |
| 34 | be connected to two anti-parallel diodes. These values can be read | |
| 35 | as temp3 and temp4. If only one diode is attached to this channel, temp4 | |
| 36 | will show as "fault". The module parameter "apd=0" can be used to suppress | |
| 37 | this 4th channel when anti-parallel diodes are not fitted. |