1.. SPDX-License-Identifier: GPL-2.0-or-later
2
3Kernel driver max6620
4=====================
5
6Supported chips:
7
8    Maxim MAX6620
9
10    Prefix: 'max6620'
11
12    Addresses scanned: none
13
14    Datasheet: http://pdfserv.maxim-ic.com/en/ds/MAX6620.pdf
15
16Authors:
17    - L\. Grunenberg <contact@lgrunenberg.de>
18    - Cumulus Networks <support@cumulusnetworks.com>
19    - Shuotian Cheng <shuche@microsoft.com>
20    - Arun Saravanan Balachandran <Arun_Saravanan_Balac@dell.com>
21
22Description
23-----------
24
25This driver implements support for Maxim MAX6620 fan controller.
26
27The driver configures the fan controller in RPM mode. To give the readings more
28range or accuracy, the desired value can be set by a programmable register
29(1, 2, 4, 8, 16 or 32). Set higher values for larger speeds.
30
31The driver provides the following sensor access in sysfs:
32
33================ ======= =====================================================
34fan[1-4]_alarm   ro      Fan alarm.
35fan[1-4]_div     rw      Sets the nominal RPM range of the fan. Valid values
36                         are 1, 2, 4, 8, 16 and 32.
37fan[1-4]_input   ro      Fan speed in RPM.
38fan[1-4]_target  rw      Desired fan speed in RPM.
39================ ======= =====================================================
40
41Usage notes
42-----------
43
44This driver does not auto-detect devices. You will have to instantiate the
45devices explicitly. Please see Documentation/i2c/instantiating-devices.rst for
46details.
47