1.\" 2.\" SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3.\" 4.\" Copyright (c) 2020 Andriy Gapon <avg@FreeBSD.org> 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 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. 14.\" 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 24.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25.\" SUCH DAMAGE. 26.\" 27.\" $FreeBSD$ 28.\" 29.Dd August 12, 2020 30.Dt CP2112 4 31.Os 32.Sh NAME 33.Nm cp2112 34.Nd driver for a USB GPIO and I2C peripheral device 35.Sh SYNOPSIS 36To compile this driver into the kernel, 37place the following lines in your 38kernel configuration file: 39.Bd -ragged -offset indent 40.Cd "device cp2112" 41.Cd "device usb" 42.Cd "device gpio" 43.Cd "device iicbus" 44.Ed 45.Pp 46Alternatively, to load the driver as a 47module at boot time, place the following line in 48.Xr loader.conf 5 : 49.Bd -literal -offset indent 50cp2112_load="YES" 51.Ed 52.Sh DESCRIPTION 53The 54.Nm 55driver provides support for Silicon Labs CP2112 device. 56The device has 8 general purpose I/O pins and an I2C controller that supports 57a subset of the I2C protocol. 58.Pp 59All pins support both input and output modes. 60An output pin can be configured either for open-drain or push-pull operation. 61Pins 0, 1 and 7 support special functions: I2C transmit indication, 62I2C receive indication and clock output respectively. 63At the moment the 64.Nm 65driver does not provide a way to enable and configure the special functions. 66.Pp 67The I2C controller supports read transactions with up to 512 bytes of data, 68write transactions with up to 61 bytes of data and a write followed by 69the repeated start followed by a read transactions where the write can be 70up to 16 bytes and the read can be up to 512 bytes. 71Zero length transfers are not supported. 72The 73.Nm 74driver creates a 75.Xr gpio 4 76and 77.Xr iicbus 4 78child buses to expose the respective functions. 79.Sh SEE ALSO 80.Xr gpio 4 , 81.Xr iicbus 4 , 82.Xr usb 4 83.Sh HISTORY 84The 85.Nm 86driver and this manual page was written by 87.An Andriy Gapon Aq Mt avg@FreeBSD.org . 88