Re: [PATCH v11 0/7] Introduction of PSCR Framework and Related Components

[Oleksij Rempel <o.rempel@pengutronix.de>]

Hi Greg,

this patch series doesn’t belong to any single existing subsystem. It
spans drivers like power/reset/, touches nvmem, regulator, and adds new
interfaces.

Since there's no clear maintainer fit and the code is self-contained,
I’d like to ask you to pick it up.

The latest version is v11 and has addressed all review comments.

Thanks!
Oleksij

On Wed, Jun 18, 2025 at 02:02:48PM +0200, Oleksij Rempel wrote:
> changes v11:
> - add missing break reported by kernel test robot <lkp@intel.com>
> 
> changes v10:
> - add some add Reviewed-by tags
> - regulator_handle_critical: set pscr = PSCR_UNKNOWN for default case
> - make g_pscrr static
> 
> changes v9:
> - Remove redundant pr_crit() messages before hw_protection_trigger()
> - Replace psc_reason_to_str() switch with static const string array
> - Mark psc_last_reason as static
> 
> changes v8:
> - Use DEFINE_GUARD() and guard(g_pscrr) for scoped locking of the global
>   pscrr_core struct
> - Replace manual mutex_lock/unlock with automatic cleanup-based guard()
>   usage
> - Centralize backend and locking state in struct pscrr_core
> - Prepare for future multi-backend support with clean encapsulation
> - Improve sysfs documentation:
>   * Added full enum psc_reason value table
>   * Simplified example comments, removed redundant "may differ" phrasing
>   * Added note that not all values are supported on all systems
>   * Linked value definitions to include/linux/reboot.h
>   * Added clear read/write usage examples for sysfs entries
> 
> changes v7:
> - document expected values in sysfs documentation
> - make write support optional
> 
> changes v6:
> - add sysfs documentation
> - rebase against latest hw_protection_reboot changes:
>   https://web.git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git/commit/?h=mm-nonmm-unstable&id=212dd3f6e57f6af8ed3caa23b93adc29334f9652
> - push core part of the reset reason the kernel/reboot.c
> 
> changes v5:
> - fix compile with NVMEM=n and potential issues with NVMEM=m
> 
> changes v4:
> - fix compile with CONFIG_PSCRR=n
> 
> changes v3
> - rework to remove devicetree dependencies
> - extend NVMEM to search devices and cells by names.
> 
> changes v2:
> - rename the framework from PSCR to PSCRR (last R is for Recorder)
> - extend power on reason header and use it to show detected reason on
>   system start and in sysfs.
> - remove "unknow" reason
> - rebase on top of v6.8-rc1
> - yaml fixes
> - zero reason state on boot
> 
> Hello all,
> 
> This patch series introduces the Power State Change Reasons Recording
> (PSCRR) framework and its related components into the kernel. The PSCR
> framework is designed for systems where traditional methods of storing
> power state change reasons, like PMICs or watchdogs, are inadequate. It
> provides a structured way to store reasons for system shutdowns and
> reboots, such as under-voltage or software-triggered events, in
> non-volatile hardware storage.
> 
> These changes are critical for systems requiring detailed postmortem
> analysis and where immediate power-down scenarios limit traditional
> storage options. The framework also assists bootloaders and early-stage
> system components in making informed recovery decisions.
> 
> 
> 
> Oleksij Rempel (7):
>   power: Extend power_on_reason.h for upcoming PSCRR framework
>   reboot: hw_protection_trigger: use standardized numeric
>     shutdown/reboot reasons instead of strings
>   power: reset: Introduce PSCR Recording Framework for Non-Volatile
>     Storage
>   nvmem: provide consumer access to cell size metrics
>   nvmem: add support for device and sysfs-based cell lookups
>   power: reset: add PSCR NVMEM Driver for Recording Power State Change
>     Reasons
>   Documentation: Add sysfs documentation for PSCRR reboot reason
>     tracking
> 
>  .../ABI/testing/sysfs-kernel-reboot-pscrr     |  74 ++++
>  drivers/nvmem/core.c                          | 134 ++++++
>  drivers/platform/chrome/cros_ec_lpc.c         |   2 +-
>  drivers/power/reset/Kconfig                   |  47 ++
>  drivers/power/reset/Makefile                  |   2 +
>  drivers/power/reset/pscrr-nvmem.c             | 254 +++++++++++
>  drivers/power/reset/pscrr.c                   | 405 ++++++++++++++++++
>  drivers/regulator/core.c                      |  16 +-
>  drivers/regulator/irq_helpers.c               |   9 +-
>  drivers/thermal/thermal_core.c                |   3 +-
>  include/linux/nvmem-consumer.h                |  25 ++
>  include/linux/power/power_on_reason.h         |   4 +
>  include/linux/pscrr.h                         |  58 +++
>  include/linux/reboot.h                        |  77 +++-
>  kernel/reboot.c                               |  85 +++-
>  15 files changed, 1173 insertions(+), 22 deletions(-)
>  create mode 100644 Documentation/ABI/testing/sysfs-kernel-reboot-pscrr
>  create mode 100644 drivers/power/reset/pscrr-nvmem.c
>  create mode 100644 drivers/power/reset/pscrr.c
>  create mode 100644 include/linux/pscrr.h
> 
> --
> 2.39.5
> 
> 

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