.\" $NetBSD: scmdspi.4,v 1.1 2021/12/07 17:39:54 brad Exp $
.\"
.\" Copyright (c) 2021 Brad Spencer <brad@anduin.eldar.org>
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
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.\"
.Dd December 1, 2021
.Dt SCMDSPI 4
.Os
.Sh NAME
.Nm scmdspi
.Nd SPI frontend to the Sparkfun Serial Controlled Motor Driver
.Sh SYNOPSIS
.Cd "scmd* at spi? slave 0"
.Cd "scmd* at spi? slave 1"
.Sh DESCRIPTION
The
.Nm
driver provides the SPI frontend attachment for the Sparkfun SCMD device.
.Sh SYSCTL VARIABLES
The following
.Xr sysctl 3
variables are inherited from
.Xr scmd 4
:
.Bl -tag -width indent
.It Li hw.scmd0.debug
If the driver is compiled with
.Dv SCMD_DEBUG ,
this node will appear and can be used to set the debugging level.
.El
.Sh FILES
.Bl -tag -width /dev/rcaXXXXX -compact
.It Pa /dev/scmd Ns Ar u
character device allowing access to the register space of a main
.Ar u ,
SCMD device
.Sh SEE ALSO
.Xr iic 4 ,
.Xr spi 4 ,
.Xr scmdi2c 4 ,
.Xr scmdspi 4 ,
.Xr scmdctl 1 ,
.Xr sysctl 8
.Sh HISTORY
The
.Nm
driver first appeared in
.Nx 10.0 .
.Sh AUTHORS
.An -nosplit
The
.Nm
driver was written by
.An Brad Spencer Aq Mt brad@anduin.eldar.org .
.Sh BUGS
When used in SPI mode, the SCMD device uses an odd method of doing reads
that can become stuck.  See the command spi_read_one in the
.Xr scmdctl 1
utility to try and unstick the device when this happens.