Holt HI-311x and Microchip MCP251x SPI CAN bus controllers
Standalone CAN bus controller chips that attach over SPI, letting embedded Linux systems talk to automotive and industrial CAN networks. Covers Microchip's long-running MCP2510/MCP2515 family, widely used on Raspberry Pi CAN HATs and industrial gateways, and Holt's HI-3110 family aimed at avionics and rugged use; both are still sold new in 2025.
recommendation
It should stay in the kernel because the supported chips are still actively sold by both Microchip and Holt in 2025, and the drivers are seeing real maintenance, including bug fixes backported to stable as recently as 2026. These are common building blocks for adding CAN bus connectivity to embedded Linux boards such as Raspberry Pi HATs and industrial gateways, so removing them would strand a lot of working hardware.
repository signals
sources
- lore.kernel.org
`mcp251x.c` had active upstream maintenance in 2026, including a bug fix backported to stable.
- lore.kernel.org
`hi311x.c` also had active 2026 maintenance and stable backports, arguing against deprecation.
- holtic.com
Holt still advertises the HI-3110 family as current standalone CAN controllers.
- holtic.com
Holt still publishes an HI-3110 evaluation-board page with a datasheet updated in 2025, indicating ongoing product availability/support.
- ww1.microchip.com
Microchip's MCP2515 family datasheet includes active ordering/package information, supporting continued market availability.
codex reasoning notes (technical)
Local source inspection via shell showed this directory contains two real SPI CAN drivers (`hi311x.c`, `mcp251x.c`) plus a newer `mcp251xfd/` subdir outside the phase-1 file count. `lore_file_timeline` on both C files showed fresh 2026 fixes and stable backports, with no obtained evidence of removal discussion; a `lore_regex` removal query timed out and `lei` was blocked by sandbox socket permissions, so the conclusion relies on the positive activity signal plus the provided static commit data. Vendor availability evidence came from web search restricted to `microchip.com` and `holtic.com`. Because the supported chips are still sold and the drivers are seeing real maintenance, this should be kept rather than deprecated; there is no direct upstream replacement for the same installed hardware, so `replacement_driver` is null.