1.\" 2.\" Copyright (c) 2018 Ian Lepore <ian@freebsd.org> 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 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 ``AS IS'' AND ANY EXPRESS OR 16.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25.\" 26.Dd July 9, 2018 27.Dt IMX_SPI 4 28.Os 29.Sh NAME 30.Nm imx_spi 31.Nd device driver for the NXP i.MX family Serial Peripheral Interface (SPI) 32.Sh SYNOPSIS 33To compile this driver into the kernel, 34place the following line in your 35kernel configuration file: 36.Bd -ragged -offset indent 37.Cd "device imx_spi" 38.Ed 39.Pp 40Alternatively, to load the driver as a 41module at boot time, place the following line in 42.Xr loader.conf 5 : 43.Bd -literal -offset indent 44imx_spi_load="YES" 45.Ed 46.Sh DESCRIPTION 47The 48.Nm 49driver provides support for the 50.Sq ECSPI 51(Enhanced Configurable SPI) hardware present on the NXP i.MX family 52of processors. 53While the ECSPI hardware supports both master and slave mode, 54this driver currently operates only in master mode. 55.Pp 56Due to hardware quirks, the 57.Nm 58driver requires that all chip select pins be configured as GPIO pins. 59Use the FDT property 60.Sq cs-gpios 61to specify which pins to use as chip selects. 62You may use any GPIO pins, including the ones that the hardware would 63normally use as SPI select pins; just configure them as GPIO in the 64.Xr fdt_pinctrl 4 65data. 66.Pp 67.Sh SYSCTL VARIABLES 68The following variables are available via 69.Xr sysctl 8 , 70and as 71.Xr loader 8 72tunables: 73.Bl -tag -width indent 74.It Va dev.imx_spi.%d.debug 75Output debugging info when non-zero. 76A value of 1 displays information about bus transfers, 772 adds information about bus clock frequency and chip select activity, 78and 3 adds information about interrupt handling. 79.El 80.Sh SEE ALSO 81.Xr fdt 4 , 82.Xr fdt_pinctrl 4 , 83.Xr sysctl 8 84.Sh HISTORY 85The 86.Nm 87driver first appeared in 88.Fx 12.0 . 89