Re: [PATCH 0/3] Implement vendor resets for PSCI SYSTEM_RESET2

[Krzysztof Kozlowski]

On 17/11/2023 22:18, Elliot Berman wrote:
> The PSCI SYSTEM_RESET2 call allows vendor firmware to define additional
> reset types which could be mapped to the reboot argument.
> 
> Setting up reboot on Qualcomm devices can be inconsistent from chipset
> to chipset.  Generally, there is a PMIC register that gets written to
> decide the reboot type. There is also sometimes a cookie that can be
> written to indicate that the bootloader should behave differently than a
> regular boot. These knobs evolve over product generations and require 
> more drivers. Qualcomm firmwares are beginning to expose vendor
> SYSTEM_RESET2 types to simplify driver requirements from Linux.
> 
> Add support in PSCI to statically wire reboot mode commands from
> userspace to a vendor reset and cookie value using the device tree. The
> DT bindings are similar to reboot mode framework except that 2
> integers are accepted (the type and cookie). Also, reboot mode framework
> is intended to program, but not reboot, the host. PSCI SYSTEM_RESET2
> does both. I've not added support for reading ACPI tables since I don't
> have any device which provides them + firmware that supports vendor
> SYSTEM_RESET2 types.
> 
> Previous discussions around SYSTEM_RESET2:
> - https://lore.kernel.org/lkml/20230724223057.1208122-2-quic_eberman@xxxxxxxxxxx/T/
> - https://lore.kernel.org/all/4a679542-b48d-7e11-f33a-63535a5c68cb@xxxxxxxxxxx/

Please link here upstream DTS user for this.

Best regards,
Krzysztof