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