I’m trying to activate SPI on a BBB. I think it’s nearly there, save for a lack of anything in /dev, which is mysterious.
I’m trying for SPI0 (I understand SPI1 requires HDMI deactivation).
Brand new A5C board, uname -a is
Linux beaglebone 3.8.13 #1 SMP Tue Jun 18 02:11:09 EDT 2013 armv7l GNU/Linux
Followed http://elinux.org/BeagleBone_Black_Enable_SPIDEV, save for
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my /lib/firmware already had BB-SPI0, so I used that
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I didn’t understand “Go to My Computer>BeagleBone Getting Started>”. The mounted USB drive device is read-only. I modified the uEnv.txt in /boot, seems to work.
Slots shows it there:
root@beaglebone:~# cat /sys/devices/bone_capemgr.8/slots
0: 54:PF—
1: 55:PF—
2: 56:PF—
3: 57:PF—
4: ff:P-O-L Bone-LT-eMMC-2G,00A0,Texas Instrument,BB-BONE-EMMC-2G
5: ff:P-O-L Bone-Black-HDMI,00A0,Texas Instrument,BB-BONELT-HDMI
7: ff:P-O-L Override Board Name,00A0,Override Manuf,BB-SPI0
root@beaglebone:~# cat /sys/kernel/debug/pinctrl/44e10800.pinmux/pingroups
registered pin groups:
…
group: pinmux_bb_spi0_pins
pin 84 (44e10950)
pin 85 (44e10954)
pin 86 (44e10958)
pin 87 (44e1095c)
…
It appears in the dmesg output
root@beaglebone:/dev# dmesg |grep SPI
[ 0.000000] Kernel command line: console=ttyO0,115200n8 quiet drm.debug=7 capemgr.enable_partno=BB-SPI0 root=/dev/mmcblk0p2 ro rootfstype=ext4 rootwait
[ 0.399220] bone-capemgr bone_capemgr.8: enabled_partno part_number ‘BB-SPI0’, version ‘N/A’
[ 0.399293] bone-capemgr bone_capemgr.8: slot #7: ‘Override Board Name,00A0,Override Manuf,BB-SPI0’
[ 0.404238] bone-capemgr bone_capemgr.8: loader: before slot-7 BB-SPI0:00A0 (prio 0)
[ 0.404261] bone-capemgr bone_capemgr.8: loader: check slot-7 BB-SPI0:00A0 (prio 0)
[ 0.404286] bone-capemgr bone_capemgr.8: loader: after slot-7 BB-SPI0:00A0 (prio 0)
[ 0.404315] bone-capemgr bone_capemgr.8: slot #7: Requesting part number/version based 'BB-SPI0-00A0.dtbo
[ 0.404345] bone-capemgr bone_capemgr.8: slot #7: Requesting firmware ‘BB-SPI0-00A0.dtbo’ for board-name ‘Override Board Name’, version ‘00A0’
[ 0.404401] bone-capemgr bone_capemgr.8: slot #7: dtbo ‘BB-SPI0-00A0.dtbo’ loaded; converting to live tree
[ 0.409351] bone-capemgr bone_capemgr.8: loader: done slot-7 BB-SPI0:00A0 (prio 0)
But no /dev/spi*. Am I expected to mkdev for that? What am I missing ?