[PATCH v2 0/6] qcom: Add NVMEM bitfield support and reboot‑mode integration

[Aswin Murugan]

This patch series introduces bit-level granularity to NVMEM cells and
adds complete reboot-mode support for Qualcomm platforms that store
reboot reasons in PMIC registers.

Qualcomm SoCs rely on PMIC-backed reboot reason storage to implement
features like "reboot bootloader" for entering fastboot mode. However,
these PMIC registers often pack multiple fields into a single byte,
requiring fine-grained bit access that the current NVMEM subsystem does
not support.

In addition, PMIC generations differ in how reboot-related data is
stored: older PMICs use PON (Power On) registers, while newer ones
provide SDAM regions. This series introduces a unified, NVMEM-based
approach that works seamlessly across both architectures.

This version also integrates reboot-mode handling into Qualcomm board
initialization, enabling automatic fastboot entry when the reboot reason
indicates bootloader mode.

Signed-off-by: Aswin Murugan <aswin.murugan at oss.qualcomm.com>

---
Changes in v2:
1. Replaced custom reboot reason handling with the standard U-Boot
   reboot-mode subsystem, per review feedback.
2. Added bit-field support to the NVMEM core using the new "bits"
   property.
3. Introduced the Qualcomm SPMI SDAM driver for unified PMIC storage
   access.
4. Updated the reboot-mode driver to support variable-sized NVMEM cells.
5. Added device tree configuration for the QCS615 RIDE board.
6. Enabled reboot-mode in qcom_defconfig.
7. Integrated reboot-mode detection into Snapdragon board
   initialization:
   - Added qcom_handle_reboot_mode() in board_late_init() to enable
     automatic fastboot entry on "reboot bootloader".

Link to v1:
https://lore.kernel.org/all/20260108065533.1143179-1-aswin.murugan@oss.qualcomm.com/
---

Aswin Murugan (6):
  reboot-mode: Use actual cell size instead of sizeof(u32)
  misc: Add support for bit fields in NVMEM cells
  misc: qcom: Add Qualcomm SPMI SDAM NVMEM driver
  mach-snapdragon: Integrate reboot-mode handling
  dts: qcs615-ride-u-boot.dtsi: Add reboot-mode support
  qcom_defconfig: Enable reboot-mode support in qcom_defconfig

 arch/arm/dts/qcs615-ride-u-boot.dtsi    |  26 +++
 arch/arm/mach-snapdragon/board.c        |  56 ++++--
 configs/qcom_defconfig                  |   3 +
 drivers/misc/Kconfig                    |   8 +
 drivers/misc/Makefile                   |   1 +
 drivers/misc/nvmem.c                    | 241 ++++++++++++++++++++++--
 drivers/misc/qcom-spmi-sdam.c           | 200 ++++++++++++++++++++
 drivers/reboot-mode/reboot-mode-nvmem.c |   5 +-
 include/nvmem.h                         |   4 +
 9 files changed, 517 insertions(+), 27 deletions(-)
 create mode 100644 drivers/misc/qcom-spmi-sdam.c

-- 
2.34.1