AMD-Xilinx Versal Watchdog Driver Coming In Linux 6.5

There's been a lot of AMD-Xilinx code going upstream in the Linux kernel over the past few months to benefit AMD's embedded efforts from the QDMA driver to CDX bus to XDMA and more. The latest hitting the kernel is an AMD-Xilinx Versal watchdog driver.

The AMD (Xilinx) Versal is an adaptive SoC from cloud to edge computing scenarios. The SoCs are promoted as "compute faster, smarter, safer." On the safer side, Linux 6.5 is adding a watchdog driver for being able to reset the system if problems are detected.

The AMD-Xilinx Versal watchdog driver Kconfig help text describes the new driver as:

"Window watchdog driver for the versal_wwdt IP core. Window watchdog timer(WWDT) contains closed(first) and open(second) window with 32 bit width. Write to the watchdog timer within predefined window periods of time. This means a period that is not too soon and a period that is not too late. The WWDT has to be restarted within the open window time. If software tries to restart WWDT outside of the open window time period, it generates a reset."

This new watchdog driver was submitted today as part of the watchdog updates for Linux 6.5. This pull also adds Hygon FCH/SCH server controller hub support to the sp5100_tco driver. That Hygon support just follows the existing code-paths used by AMD but with the Hygon identifier added for dealing with those Chinese CPUs based on Zen 1.