2 .\" SPDX-License-Identifier: BSD-2-Clause
4 .\" Copyright (c) 2020 Andriy Gapon <avg@FreeBSD.org>
6 .\" Redistribution and use in source and binary forms, with or without
7 .\" modification, are permitted provided that the following conditions
9 .\" 1. Redistributions of source code must retain the above copyright
10 .\" notice, this list of conditions and the following disclaimer.
11 .\" 2. Redistributions in binary form must reproduce the above copyright
12 .\" notice, this list of conditions and the following disclaimer in the
13 .\" documentation and/or other materials provided with the distribution.
15 .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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27 .\" $FreeBSD: head/share/man/man4/cp2112.4 364144 2020-08-12 09:42:05Z avg $
34 .Nd driver for the PCF8591 8-bit A/D and D/A converter
36 To compile this driver into the kernel,
37 place the following lines in your
38 kernel configuration file:
39 .Bd -ragged -offset indent
44 Alternatively, to load the driver as a
45 module at boot time, place the following line in
47 .Bd -literal -offset indent
53 driver supports reading four inputs and setting one output over I2C.
54 The hardware supports configuring the input lines as:
57 four single-ended inputs
59 three differential inputs (one input line is shared between all three inputs)
61 two single-ended inputs and one differential input
63 two differential inputs.
68 driver reports data via
70 entries in the device's node in the
73 .Bl -tag -width inputs.%d
75 The input level of the corresponding input in steps between 0 and 255.
76 Absolute voltage depends on an actual reference voltage.
81 based system the following properties must be set:
82 .Bl -tag -width "compatible"
84 Must be set to "nxp,pcf8591".
88 It should be in the range from 0x40 to 0x4f (7-bit).
93 device usually looks like:
99 compatible = "nxp,pcf8591";
111 driver and this manual page was written by
112 .An Andriy Gapon Aq Mt avg@FreeBSD.org .
116 driver does not support changing the input configuration.
117 All input lines are configured as single-ended inputs.
121 driver does not support setting the output.
122 It is always disabled (tri-state).