1 .. SPDX-License-Identifier: GPL-2.0
2
3 =============================
4 AD525x Digital Potentiometers
5 =============================
6
7 The ad525x_dpot driver exports a simple sysfs
8 work with the immediate resistance settings as
9 settings. Access to the factory programmed to
10 interpretation of this settings is required by
11 the specific part in use.
12
13 Files
14 =====
15
16 Each dpot device will have a set of eeprom, rd
17 many depends on the actual part you have, as w
18
19 The eeprom files are used to program the start
20
21 The rdac files are used to program the immedia
22
23 The tolerance files are the read-only factory
24 and may vary greatly on a part-by-part basis.
25 this field, please consult the datasheet for y
26 as a hex file for easier parsing.
27
28 Example
29 =======
30
31 Locate the device in your sysfs tree. This is
32 the common i2c directory and locating the devi
33
34 # ls /sys/bus/i2c/devices/
35 0-0022 0-0027 0-002f
36
37 So assuming the device in question is on the f
38 address of 0x2f, we descend (unrelated sysfs e
39
40 # ls /sys/bus/i2c/devices/0-002f/
41 eeprom0 rdac0 tolerance0
42
43 You can use simple reads/writes to access thes
44
45 # cd /sys/bus/i2c/devices/0-002f/
46
47 # cat eeprom0
48 0
49 # echo 10 > eeprom0
50 # cat eeprom0
51 10
52
53 # cat rdac0
54 5
55 # echo 3 > rdac0
56 # cat rdac0
57 3
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