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 <[email protected]> --- 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/[email protected]/ --- 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
