| Kernel driver emc1403 |
| ===================== |
| |
| Supported chips: |
| * SMSC / Microchip EMC1402, EMC1412 |
| Addresses scanned: I2C 0x18, 0x1c, 0x29, 0x4c, 0x4d, 0x5c |
| Prefix: 'emc1402' |
| Datasheets: |
| http://ww1.microchip.com/downloads/en/DeviceDoc/1412.pdf |
| http://ww1.microchip.com/downloads/en/DeviceDoc/1402.pdf |
| * SMSC / Microchip EMC1403, EMC1404, EMC1413, EMC1414 |
| Addresses scanned: I2C 0x18, 0x29, 0x4c, 0x4d |
| Prefix: 'emc1403', 'emc1404' |
| Datasheets: |
| http://ww1.microchip.com/downloads/en/DeviceDoc/1403_1404.pdf |
| http://ww1.microchip.com/downloads/en/DeviceDoc/1413_1414.pdf |
| * SMSC / Microchip EMC1422 |
| Addresses scanned: I2C 0x4c |
| Prefix: 'emc1422' |
| Datasheet: |
| http://ww1.microchip.com/downloads/en/DeviceDoc/1422.pdf |
| * SMSC / Microchip EMC1423, EMC1424 |
| Addresses scanned: I2C 0x4c |
| Prefix: 'emc1423', 'emc1424' |
| Datasheet: |
| http://ww1.microchip.com/downloads/en/DeviceDoc/1423_1424.pdf |
| |
| Author: |
| Kalhan Trisal <kalhan.trisal@intel.com |
| |
| |
| Description |
| ----------- |
| |
| The Standard Microsystems Corporation (SMSC) / Microchip EMC14xx chips |
| contain up to four temperature sensors. EMC14x2 support two sensors |
| (one internal, one external). EMC14x3 support three sensors (one internal, |
| two external), and EMC14x4 support four sensors (one internal, three |
| external). |
| |
| The chips implement three limits for each sensor: low (tempX_min), high |
| (tempX_max) and critical (tempX_crit.) The chips also implement an |
| hysteresis mechanism which applies to all limits. The relative difference |
| is stored in a single register on the chip, which means that the relative |
| difference between the limit and its hysteresis is always the same for |
| all three limits. |
| |
| This implementation detail implies the following: |
| * When setting a limit, its hysteresis will automatically follow, the |
| difference staying unchanged. For example, if the old critical limit |
| was 80 degrees C, and the hysteresis was 75 degrees C, and you change |
| the critical limit to 90 degrees C, then the hysteresis will |
| automatically change to 85 degrees C. |
| * The hysteresis values can't be set independently. We decided to make |
| only temp1_crit_hyst writable, while all other hysteresis attributes |
| are read-only. Setting temp1_crit_hyst writes the difference between |
| temp1_crit_hyst and temp1_crit into the chip, and the same relative |
| hysteresis applies automatically to all other limits. |
| * The limits should be set before the hysteresis. |