adafruit beaglebone cape universal spi pin config

adafruit beaglebone cape universal spi pin config.txt

Here is example of configuring the SPI0 pins.

First, verify cape unverisal is loaded:
[quote]
root@beaglebone:~# cat /sys/devices/platform/bone_capemgr/slots
 0: PF----  -1 
 1: PF----  -1 
 2: PF----  -1 
 3: PF----  -1 
 4: P-O-L-   0 Override Board Name,00A0,Override Manuf,cape-universaln

root@beaglebone:~# uname -a
Linux beaglebone 4.4.11-ti-r29 #1 SMP Fri May 27 22:58:36 UTC 2016 armv7l GNU/Linux

root@beaglebone:~# cat /etc/dogtag
BeagleBoard.org Debian Image 2016-06-05
[/quote]

Next check the possible modes for the pins:
[quote]
root@beaglebone:~# config-pin -l P9.17
default gpio gpio_pu gpio_pd spi i2c pwm
root@beaglebone:~# config-pin -l P9.17   #SPI0_CS
default gpio gpio_pu gpio_pd spi i2c pwm
root@beaglebone:~# config-pin -l P9.18   #SPI0_D1
default gpio gpio_pu gpio_pd spi i2c pwm
root@beaglebone:~# config-pin -l P9.22   #SPI0_SCLK
default gpio gpio_pu gpio_pd spi uart i2c pwm
root@beaglebone:~# config-pin -l P9.21   #SPI0_D0
default gpio gpio_pu gpio_pd spi uart i2c pwm
[/quote]

Set the SPI0 pins to spi mode:
[quote]
root@beaglebone:~# config-pin P9.17 spi  #SPI0_CS
root@beaglebone:~# config-pin P9.18 spi  #SPI0_1
root@beaglebone:~# config-pin P9.21 spi  #SPI0_D0
root@beaglebone:~# config-pin P9.22 spi  #SPI0_SCLK
[/quote]

Check that the pins were set to SPI mode OK:
[quote]
root@beaglebone:~# config-pin -q P9.17
P9_17 Mode: spi
root@beaglebone:~# config-pin -q P9.18
P9_18 Mode: spi
root@beaglebone:~# config-pin -q P9.21
P9_21 Mode: spi
root@beaglebone:~# config-pin -q P9.22
P9_22 Mode: spi
[/quote]