2 .\" SPDX-License-Identifier: BSD-2-Clause
4 .\" Copyright (c) 2019 Ian Lepore <ian@freebsd.org>
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34 .Nd driver for I2C mux hardware controlled via GPIO
36 To compile this driver into the kernel,
37 place the following line in your
38 kernel configuration file:
39 .Bd -ragged -offset indent
40 .Cd "device iic_gpiomux"
43 Alternatively, to load the driver as a
44 module at boot time, place the following line in
46 .Bd -literal -offset indent
47 iic_gpiomux_load="YES"
52 driver supports any type of I2C bus multiplexer (mux) hardware that
53 is controlled by manipulating the state of one or more GPIO pins.
54 It automatically connects an upstream I2C bus to one of the downstream
55 buses as needed when slave devices on the downstream buses initiate I/O.
56 More information on the automatic switching behavior is available in
63 device node may be defined as a child node of any arbitrary bus
67 property indicates the connection to the upstream I2C bus.
70 node are additional i2c buses, which will have their own i2c slave
71 devices described in their child nodes.
75 driver conforms to the standard
77 .Li i2c/i2c-mux-gpio.txt
86 driver first appeared in