| Michael Walle | 3f69702 | 2020-09-14 23:43:36 +0200 | [diff] [blame] | 1 | .. SPDX-License-Identifier: GPL-2.0-only |
| 2 | |
| 3 | Kernel driver sl28cpld |
| 4 | ====================== |
| 5 | |
| 6 | Supported chips: |
| 7 | |
| 8 | * Kontron sl28cpld |
| 9 | |
| 10 | Prefix: 'sl28cpld' |
| 11 | |
| 12 | Datasheet: not available |
| 13 | |
| 14 | Authors: Michael Walle <michael@walle.cc> |
| 15 | |
| 16 | Description |
| 17 | ----------- |
| 18 | |
| 19 | The sl28cpld is a board management controller which also exposes a hardware |
| 20 | monitoring controller. At the moment this controller supports a single fan |
| 21 | supervisor. In the future there might be other flavours and additional |
| 22 | hardware monitoring might be supported. |
| 23 | |
| 24 | The fan supervisor has a 7 bit counter register and a counter period of 1 |
| 25 | second. If the 7 bit counter overflows, the supervisor will automatically |
| 26 | switch to x8 mode to support a wider input range at the loss of |
| 27 | granularity. |
| 28 | |
| 29 | Sysfs entries |
| 30 | ------------- |
| 31 | |
| 32 | The following attributes are supported. |
| 33 | |
| 34 | ======================= ======================================================== |
| 35 | fan1_input Fan RPM. Assuming 2 pulses per revolution. |
| 36 | ======================= ======================================================== |