[v9,0/7] Introduction of PSCR Framework and Related Components

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                   | 403 ++++++++++++++++++
 drivers/regulator/core.c                      |  13 +-
 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, 1168 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

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2.39.5