Re: [PATCH v23 07/13] power: reset: Add psci-reboot-mode driver

[Shivendra Pratap <shivendra.pratap@oss.qualcomm.com>]

On 22-07-2026 14:30, Pavan Kondeti wrote:
> On Tue, Jul 14, 2026 at 10:46:35PM +0530, Shivendra Pratap wrote:
>> PSCI supports different types of resets like SYSTEM_RESET, SYSTEM_RESET2
>> ARCH WARM reset and SYSTEM_RESET2 vendor-specific resets. Currently
>> there is no common driver that handles all supported psci resets at one
>> place. Additionally, there is no common mechanism to issue the supported
>> psci resets from userspace.
>>
>> Add a psci-reboot-mode driver, and define two types of PSCI resets,
>> predefined-resets and vendor-specific resets. Predefined-resets are
>> defined by psci driver and vendor-specific resets are defined by SoC
>> vendors, under the psci:reboot-mode node of SoC device tree.
>>
>> Register the driver with the reboot-mode framework to interface these
>> resets to userspace. When userspace initiates a supported command, pass
>> the reset arguments to the PSCI driver to enable command-based reset.
>>
>> This change allows userspace to issue supported PSCI reset commands
>> using the standard reboot system calls while enabling SoC vendors to
>> define their specific resets for PSCI.
>>
>> Signed-off-by: Shivendra Pratap <shivendra.pratap@oss.qualcomm.com>
>> ---
>>   MAINTAINERS                            |  1 +
>>   drivers/power/reset/Kconfig            | 10 +++++
>>   drivers/power/reset/Makefile           |  1 +
>>   drivers/power/reset/psci-reboot-mode.c | 78 ++++++++++++++++++++++++++++++++++
>>   4 files changed, 90 insertions(+)
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index e1ed6abef62a..4910abafa170 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -21576,6 +21576,7 @@ S:	Maintained
>>   F:	Documentation/devicetree/bindings/arm/psci.yaml
>>   F:	drivers/firmware/psci/
>>   F:	drivers/mfd/psci-mfd.c
>> +F:	drivers/power/reset/psci-reboot-mode.c
>>   F:	include/linux/psci.h
>>   F:	include/uapi/linux/psci.h
>>   
>> diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
>> index 124afb99febe..93e4029d9506 100644
>> --- a/drivers/power/reset/Kconfig
>> +++ b/drivers/power/reset/Kconfig
>> @@ -348,6 +348,16 @@ config NVMEM_REBOOT_MODE
>>   	  then the bootloader can read it and take different
>>   	  action according to the mode.
>>   
>> +config PSCI_REBOOT_MODE
>> +	bool "PSCI reboot mode driver"
>> +	depends on OF && (ARM_PSCI_FW || COMPILE_TEST)
>> +	select REBOOT_MODE
>> +	help
>> +	  Say y here will enable PSCI reboot mode driver. This gets
>> +	  the PSCI reboot mode arguments and passes them to psci
>> +	  driver. psci driver uses these arguments for issuing
>> +	  device reset into different boot states.
>> +
> 
> Since we have added predefined-resets support, why are we forcing this
> driver to depend on OF?
> 
> For example, `reboot psci-system-reset2-arch-warm-reset` gives me
> warm reset on non-DT systems, correct?

sure. Will update it. thanks.

thanks,
Shivendra