IEEE 802.15.4 low-rate wireless PAN radio transceivers
Low-power, low-data-rate radio chips used for sensor networks, smart-home meshes, and industrial telemetry built on the IEEE 802.15.4 standard (the physical layer underneath Zigbee, Thread, and 6LoWPAN). It covers SPI- and USB-attached transceivers from Atmel/Microchip (AT86RF230, ATUSB, MRF24J40), TI (CC2520), Analog Devices (ADF7242), NXP (MCR20A), and Cascoda (CA8210).
recommendation
Worth keeping but worth flagging as a niche subsystem. The directory is actively maintained, with dozens of commits and contributors over the last five years and changes as recent as March 2025, and Microchip still sells the MRF24J40 and its module variant new in 2025. Some supported chips, such as NXP's MCR20A, are end-of-life, so anyone picking hardware for a new design should check which specific transceiver is still in production rather than assuming the whole list is current.
repository signals
sources
- git.kernel.org
Upstream Kconfig shows this directory is an active IEEE 802.15.4 driver submenu containing multiple real hardware drivers plus test/simulation drivers.
- microchip.com
Microchip lists MRF24J40 as 'In Production', showing at least part of the supported hardware family is still sold new.
- microchip.com
Microchip lists the MRF24J40MD module as 'In Production', indicating current module-level availability for this subsystem.
- nxp.com
NXP marks MCR20A 'End of Life' and recommends newer parts for new designs, showing some chips in the directory are legacy even though the subsystem is not wholly obsolete.
codex reasoning notes (technical)
Not a removal candidate: prompt metadata already shows 76 substantive commits in the last 5 years, 30 authors, and a most recent substantive touch on 2025-03-06, which is active-maintenance signal. `lore_file_timeline` was queried on the directory path and returned no matches, consistent with that tool keying on exact file paths rather than directories, and I found no direct removal evidence. Shell inspection of Kconfig (`exec_command`) confirmed this directory mixes several real SPI/USB radio drivers with fakelb/hwsim test drivers. Web search (`web.search_query`) found Microchip MRF24J40/MRF24J40MD still in production, while NXP MCR20A is EOL, so the right stance is to keep the directory but annotate that parts of the hardware set are legacy and niche. No single upstream replacement driver covers the whole use case; newer silicon tends to use different chips or integrated SoCs rather than one drop-in replacement.