NAME
spi-config - set or query SPI configuration.
SYNOPSIS
spi-config options...
DESCRIPTION
Set or query the configuration of a SPI port.
- -d, --device=DEVICE
-
use the given Linux spidev character device.
- -q, --query
-
print the current configuration.
- -m, --mode=[0-3]
-
set the spi mode (see SPI MODES below).
- -l, --lsb={0,1}
-
set LSB first (1) or MSB first (0).
- -b, --bits=[7...]
-
set the number of bits per word.
- -s, --speed=FREQUENCY
-
set clock frequency (in Hz).
- -r, --spirdy={0,1}
-
set the SPI READY mode flag.
- -s, --wait
-
block, keeping the file descriptor open. See WAIT OPTION below.
- -h, --help
-
display the help screen and exit.
- -v, --version
-
display the version number and exit.
SPI MODES
- mode 0
-
low iddle level, sample on leading edge.
- mode 1
-
low iddle level, sample on trailing edge.
- mode 2
-
high iddle level, sample on leading edge.
- mode 3
-
high iddle level, sample on trailing edge.
WAIT OPTION
On some platforms, the speed is reset to a default value when the file descriptor is closed. To avoid this, one can use the -w option that keeps the file descriptor open. See also last example below.
EXAMPLES
- Get help:
-
$ spi-config -h
- Query current configuration:
-
$ spi-config --device=/dev/spidev0.0 -q
- Change clock frequency to 1 MHz:
-
$ spi-config --device=/dev/spidev0.0 --speed=1000000
- Set a configuration and keep the device open:
-
$ spi-config --wait --speed=1000000 & PID=$!
- Close device previously open:
-
$ kill $PID
AUTHOR
Written by Christophe BLAESS <http://www.blaess.fr/christophe>.
REPORTING BUGS
Github home page: <https://github.com/cpb-/spi-tools.git>
COPYRIGHT
Copyright © 2014 Christophe Blaess.
Licensed under GPLv2 <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.