Missing ARM TWD Watchdog driver?
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.dtsiarch/arm/boot/dts/arm-realview-pb11mp.dtsarch/arm/boot/dts/arm-realview-pbx-a9.dtsarch/arm/boot/dts/bcm5301x.dtsiarch/arm/boot/dts/bcm63138.dtsiarch/arm/boot/dts/bcm-hr2.dtsiarch/arm/boot/dts/bcm-nsp.dtsiarch/arm/boot/dts/berlin2cd.dtsiarch/arm/boot/dts/highbank.dtsarch/arm/boot/dts/mmp3.dtsiarch/arm/boot/dts/owl-s500.dtsiarch/arm/boot/dts/spear13xx.dtsiarch/arm/boot/dts/ste-dbx5x0.dtsiarch/arm/boot/dts/vexpress-v2p-ca5s.dtsarch/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'm not well experienced with LKML yet and I apologize for if I asked the question on the inappropriate mailing list. As per 3.3 of [1], I'm kindly asking to CC me with answers.
Thanks!
[1] The linux-kernel mailing list FAQ http://vger.kernel.org/lkml/
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Guenter Roeck
maintainerQuoted 25 lines · Boris Lysov
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' ofgit://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.dtsiarch/arm/boot/dts/arm-realview-pb11mp.dtsarch/arm/boot/dts/arm-realview-pbx-a9.dtsarch/arm/boot/dts/bcm5301x.dtsiarch/arm/boot/dts/bcm63138.dtsiarch/arm/boot/dts/bcm-hr2.dtsiarch/arm/boot/dts/bcm-nsp.dtsiarch/arm/boot/dts/berlin2cd.dtsiarch/arm/boot/dts/highbank.dtsarch/arm/boot/dts/mmp3.dtsiarch/arm/boot/dts/owl-s500.dtsiarch/arm/boot/dts/spear13xx.dtsiarch/arm/boot/dts/ste-dbx5x0.dtsiarch/arm/boot/dts/vexpress-v2p-ca5s.dtsarch/arm/boot/dts/vexpress-v2p-ca9.dts
Quoted 6 lines
and it is documented in
Documentation/devicetree/bindings/watchdog/arm,twd-wdt.yamlHowever 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
Quoted 26 lines · Guenter Roeck
Quoted 25 lines · Boris Lysov
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' ofgit://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.dtsiarch/arm/boot/dts/arm-realview-pb11mp.dtsarch/arm/boot/dts/arm-realview-pbx-a9.dtsarch/arm/boot/dts/bcm5301x.dtsiarch/arm/boot/dts/bcm63138.dtsiarch/arm/boot/dts/bcm-hr2.dtsiarch/arm/boot/dts/bcm-nsp.dtsiarch/arm/boot/dts/berlin2cd.dtsiarch/arm/boot/dts/highbank.dtsarch/arm/boot/dts/mmp3.dtsiarch/arm/boot/dts/owl-s500.dtsiarch/arm/boot/dts/spear13xx.dtsiarch/arm/boot/dts/ste-dbx5x0.dtsiarch/arm/boot/dts/vexpress-v2p-ca5s.dtsarch/arm/boot/dts/vexpress-v2p-ca9.dts
Quoted 8 lines
Quoted 6 lines
and it is documented in
Documentation/devicetree/bindings/watchdog/arm,twd-wdt.yamlHowever 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.
Likewise, AFAICT we added the binding but never the driver.
Looking at the git history, that schema was introduced in commit:
50e02e9a030a9ae3 ("dt-bindings: timer: arm,twd: Convert to json-schema")
... and replaced Documentation/devicetree/bindings/timer/arm,twd.txt
Per:
$ git log --follow Documentation/devicetree/bindings/timer/arm,twd.txt
That was introduced alongside a driver in commit:
d8e0364364d333fe ("ARM: smp_twd: add device tree support")
... which only introduced a driver for the timer, and not the watchdog, as the commit message notes.
Thanks.
Mark.
Hi Mark and Guenter,
Quoted 37 lines · Mark Rutland
Quoted 15 lines · Guenter Roeck
Quoted 14 lines · Boris Lysov
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' ofgit://git.kernel.org/pub/scm/fs/xfs/xfs-linux"),
multiple device trees declare usage of arm-twd:(...)
and it is documented in
Documentation/devicetree/bindings/watchdog/arm,twd-wdt.yamlQuoted 6 lines
Quoted 4 lines
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.
Likewise, AFAICT we added the binding but never the driver.
Looking at the git history, that schema was introduced in commit:
50e02e9a030a9ae3("dt-bindings: timer: arm,twd: Convert to json-schema")... and replaced
Documentation/devicetree/bindings/timer/arm,twd.txtPer:
$ git log --follow Documentation/devicetree/bindings/timer/arm,twd.txtThat was introduced alongside a driver in commit:
Quoted 7 lines
d8e0364364d333fe("ARM:smp_twd: add device tree support")... which only introduced a driver for the timer, and not the watchdog, as the commit message notes.
Thanks.
Mark.
Now I understand there's no ARM TWD Watchdog driver. TYVM for your replies!