Re: [PATCH v8 2/2] watchdog: Add driver for Gunyah Watchdog

[Dmitry Baryshkov]

On Tue, Nov 18, 2025 at 10:40:57AM +0000, Hrishabh Rajput via B4 Relay wrote:
> From: Hrishabh Rajput <hrishabh.rajput@xxxxxxxxxxxxxxxx>
> 
> On Qualcomm SoCs running under the Gunyah hypervisor, access to watchdog
> through MMIO is not available on all platforms. Depending on the
> hypervisor configuration, the watchdog is either fully emulated or
> exposed via ARM's SMC Calling Conventions (SMCCC) through the Vendor
> Specific Hypervisor Service Calls space.
> 
> Add driver to support the SMC-based watchdog provided by the Gunyah
> Hypervisor. Device registration is done in the QCOM SCM driver after
> checks to restrict the watchdog initialization to Qualcomm devices
> running under Gunyah.
> 
> Gunyah watchdog is not a hardware but an SMC-based vendor-specific
> hypervisor interface provided by the Gunyah hypervisor. The design
> involving QCOM SCM driver for registering the platform device has been
> devised to avoid adding non-hardware nodes to devicetree.
> 
> Tested-by: Shivendra Pratap <shivendra.pratap@xxxxxxxxxxxxxxxx>
> Tested-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
> Signed-off-by: Hrishabh Rajput <hrishabh.rajput@xxxxxxxxxxxxxxxx>
> ---
>  MAINTAINERS                   |   1 +
>  drivers/watchdog/Kconfig      |  13 +++
>  drivers/watchdog/Makefile     |   1 +
>  drivers/watchdog/gunyah_wdt.c | 261 ++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 276 insertions(+)

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxxxxxxxx>


-- 
With best wishes
Dmitry