Renesas R-Car and RZ thermal sensor units
On-chip temperature sensors built into Renesas application processors, including the R-Car Gen3/Gen4 automotive SoCs used in car infotainment and ADAS, and the RZ/G2L, RZ/G3E, RZ/G3S, and RZ/T2H industrial and HMI microprocessors. The kernel uses these sensors for thermal management, throttling, and shutdown protection.
recommendation
It should stay because the hardware is current: Renesas still actively markets the R-Car H3e, RZ/G2L (with product longevity guaranteed to 2037), RZ/G3E, RZ/G3S, and RZ/T2H, and the driver is under active development, with new SoC support added as recently as the v6.18 cycle. There is no replacement and each source file targets specific Renesas thermal IP, so removal would break working, in-production systems.
repository signals
sources
- spinics.net
Thermal pull request for v6.18-rc1 included a fix for the newly added Renesas RZ/G3E thermal driver, indicating active upstream maintenance rather than removal.
- kernel.googlesource.com
Thermal merge notes list 'thermal: renesas: rzg3e: add support for RZ/T2H and RZ/N2H', showing feature growth in this driver area in 2026.
- renesas.com
Renesas marks RZ/G3E as Active and describes current industrial/HMI applications, showing supported hardware is still marketed.
- renesas.com
Renesas marks RZ/G3S as Active, showing this family is still sold for new designs.
- renesas.com
Renesas marks RZ/G2L as Active and gives Product Longevity 2037, strong evidence of ongoing deployment horizon.
- renesas.com
Renesas marks RZ/T2H as Active; this is relevant because recent kernel work extended the Renesas thermal driver support to RZ/T2H/N2H.
- renesas.com
Renesas marks R-Car H3/H3e variants as Active for automotive cockpit/IVI use, indicating the older R-Car side of this driver family still has live deployments.
- cateee.net
LKDDb shows CONFIG_RCAR_GEN3_THERMAL present through current kernels and tied to many Renesas compatible strings in this directory.
codex reasoning notes (technical)
Local shell inspection (`sed` on Kconfig and source) shows this directory is a real multi-driver bundle for several Renesas thermal IP blocks. Local `git -c safe.directory=... log -- drivers/thermal/renesas` showed fresh substantive commits through 2026-01-21, including new SoC enablement, with no sign of a dying codepath. Web search produced the spinics pull mail and googlesource merge view for upstream activity, plus official Renesas product pages showing RZ/G3E, RZ/G3S, RZ/G2L, RZ/T2H, and R-Car H3e marked Active. No natural replacement driver exists; each file targets specific Renesas TSU/thermal hardware, so the correct disposition is to keep it.