Re: Missing ARM TWD Watchdog driver?

From: Guenter Roeck
Date: Mon Jan 17 2022 - 11:35:04 EST


On 1/17/22 8:01 AM, Boris Lysov wrote:
Hello everyone,

I stumbled upon the ARM TWD Watchdog driver which seems to be missing (or I'm
just blind).

As per commit a33f5c380c4bd3fa5278d690421b72052456d9fe ("Merge tag
'xfs-5.17-merge-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux"), multiple
device trees declare usage of arm-twd:

arch/arm/boot/dts/arm-realview-eb-mp.dtsi
arch/arm/boot/dts/arm-realview-pb11mp.dts
arch/arm/boot/dts/arm-realview-pbx-a9.dts
arch/arm/boot/dts/bcm5301x.dtsi
arch/arm/boot/dts/bcm63138.dtsi
arch/arm/boot/dts/bcm-hr2.dtsi
arch/arm/boot/dts/bcm-nsp.dtsi
arch/arm/boot/dts/berlin2cd.dtsi
arch/arm/boot/dts/highbank.dts
arch/arm/boot/dts/mmp3.dtsi
arch/arm/boot/dts/owl-s500.dtsi
arch/arm/boot/dts/spear13xx.dtsi
arch/arm/boot/dts/ste-dbx5x0.dtsi
arch/arm/boot/dts/vexpress-v2p-ca5s.dts
arch/arm/boot/dts/vexpress-v2p-ca9.dts

and it is documented in
Documentation/devicetree/bindings/watchdog/arm,twd-wdt.yaml

However I could not find the driver itself. I tried running case-insensitive
grep and ripgrep to no avail. Does this driver actually exist? Is it gone?


I may be missing it, but I do not see any evidence that it ever existed.

Guenter