Using the Microchip IEEE 802.15.4 Radio on the BeagleBone Black

To load support for the Microchip MRF24J40 execute the following:

#echo BB-BONE-MRF24J40 > /sys/devices/bone_capemgr.8/slots

This should result in following kernel debug messages:

[  883.483409] bone-capemgr bone_capemgr.8: part_number 'BB-BONE-MRF24J40', version 'N/A'
[  883.483585] bone-capemgr bone_capemgr.8: slot #6: specific override
[  883.483660] bone-capemgr bone_capemgr.8: bone: Using override eeprom data at slot 6
[  883.483716] bone-capemgr bone_capemgr.8: slot #6: 'Bone-MRF24J40,00A0,Signal 11 Softwa,BB-BONE-MRF24J40'
[  883.484028] bone-capemgr bone_capemgr.8: slot #6: Requesting firmware 'cape-bone-mrf24j40-00A0.dtbo' for board-name 'Bone-MRF24J40', version '00A0'
[  883.484113] bone-capemgr bone_capemgr.8: slot #6: dtbo 'cape-bone-mrf24j40-00A0.dtbo' loaded; converting to live tree
[  883.484629] bone-capemgr bone_capemgr.8: slot #6: #2 overlays
[  883.594180] edma-dma-engine edma-dma-engine.0: allocated channel for 0:43
[  883.594350] edma-dma-engine edma-dma-engine.0: allocated channel for 0:42
[  883.595019] mrf24j40: probe(). IRQ: 205
[  883.599630] bone-capemgr bone_capemgr.8: slot #6: Applied #2 overlays.

Kernel Patch Typo - Incompatible with baseboard

The current kernel patches has a typo in the /kernel/firmware/capes/cape-bone-mrf24j40-00A0.dts that may cause the cape manager to report it is incompatible with the baseboard. i.e.:

[  417.682368] bone-capemgr bone_capemgr.8: slot #8: Requesting firmware 'cape-bone-mrf24j40-00A0.dtbo' for board-name 'Bone-MRF24J40', version '00A0'
[  417.682392] bone-capemgr bone_capemgr.8: slot #8: dtbo 'cape-bone-mrf24j40-00A0.dtbo' loaded; converting to live tree
[  417.682595] bone-capemgr bone_capemgr.8: slot #8: Incompatible with baseboard for 'BB-BONE-MRF24J40'
[  417.692228] bone-capemgr bone_capemgr.8: slot #8: Failed verification 

If this is the case, change the following line

compatible = "ti,beaglebone", "ti-beaglebone-black";

to

compatible = "ti,beaglebone", "ti,beaglebone-black"; 

and rebuild.

I/O Conflict with HDMI

The MRF24J40 shares I/O (P9.31) with the HDMI Interface. If you don't disable the HDMI interface on boot (or unload it - glup), the following error may result:

[   23.701229] bone-capemgr bone_capemgr.8: slot #7: Requesting firmware 'cape-bone-mrf24j40-00A0.dtbo' for board-name 'Bone-MRF24J40', version '00A0'
[   23.715092] bone-capemgr bone_capemgr.8: slot #7: dtbo 'cape-bone-mrf24j40-00A0.dtbo' loaded; converting to live tree
[   23.726858] bone-capemgr bone_capemgr.8: slot #7: BB-BONE-MRF24J40 conflict P9.31 (#5:BB-BONELT-HDMI)
[   23.736629] bone-capemgr bone_capemgr.8: slot #7: Failed verification

To disable the HDMI interface, see the example at the bottom of this page.