Dallas/Maxim 1-Wire bus subsystem and device drivers
1-Wire is a low-speed single-data-line bus Dallas Semiconductor (now Analog Devices/Maxim) introduced in the 1990s for tiny peripherals like the DS18B20 digital thermometer, DS2401 serial-number chips, and small EEPROMs. This subsystem provides the bus core plus drivers for masters (GPIO bit-bang, DS2482 I2C bridge) and slave families, used in embedded and hobbyist setups.
recommendation
It should stay in the kernel because 1-Wire is a still-living niche bus with no in-tree replacement. Analog Devices (which absorbed Dallas/Maxim) still sells the DS18B20 thermometer and DS2482-100 I2C-to-1-Wire bridge as production parts in 2025, the kernel documentation remains current, and upstream was still merging functional fixes to the core as recently as December 2025. It is widely used in embedded, industrial, and hobbyist Linux systems for cheap temperature sensing and small EEPROM/ID chips.
repository signals
sources
- lore.kernel.org
Upstream was still taking functional fixes for drivers/w1/w1.c in late 2025 ('w1: fix redundant counter decrement in w1_attach_slave_device()').
- kernel.org
Current kernel documentation still describes the w1 subsystem, with active master examples including GPIO and DS2482, and current family drivers such as w1_therm.
- analog.com
The DS18B20 1-Wire thermometer is listed as PRODUCTION with current pricing/sample-and-buy information, indicating new hardware remains on sale.
- analog.com
The DS2482-100 I2C-to-1-Wire master bridge is listed as PRODUCTION with current pricing/sample-and-buy information, showing contemporary 1-Wire master hardware is still sold.
codex reasoning notes (technical)
`drivers/w1` is the Linux 1-Wire subsystem core plus bus-family support, not a dead helper directory. `lore_file_timeline(path=drivers/w1/w1.c)` showed recent LKML/stable traffic through 2025-12 and 2026-02; the cited lore URL came from that MCP result. Kernel docs URL was obtained by web search/open on kernel.org and shows the subsystem is still documented with current master/slave roles. ADI DS18B20 and DS2482-100 URLs were obtained by web search/open on analog.com and show PRODUCTION status plus ordering info, so hardware is still sold and deployed in embedded/industrial/hobby Linux systems. No natural in-tree replacement covers the same 1-Wire bus role, and the evidence points to niche-but-real ongoing deployments rather than obsolescence.