Am 30. März 2026 19:14:12 MESZ schrieb Aswin Murugan <[email protected]>: >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]>
It is unclear to me how endianness is handled in bitfields. Do you assume low-endianness or do you consider the system endianness? Please, ensure that the tests are executed on both low- and big-endian systems. Best regards Heinrich > >--- >Changes in v3: >1. Simplified bit field handling to maximum u32 size (32 bits). >2. Enforced strict size matching (size == cell->size) when nbits == 0. >3. Enhanced test function for NVMEM read & write >4. Updated NVMEM API documentation > >Link to V2: >https://lore.kernel.org/all/[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 (7): > 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 > test: dm: add comprehensive tests for NVMEM bit field operations > misc: update API documentation for bit field support in NVMEM > > arch/arm/dts/qcs615-ride-u-boot.dtsi | 26 ++++ > arch/arm/mach-snapdragon/board.c | 56 ++++++-- > arch/sandbox/dts/test.dts | 12 ++ > configs/qcom_defconfig | 3 + > drivers/misc/Kconfig | 8 ++ > drivers/misc/Makefile | 1 + > drivers/misc/nvmem.c | 159 ++++++++++++++++++--- > drivers/misc/qcom-spmi-sdam.c | 200 +++++++++++++++++++++++++++ > include/nvmem.h | 28 +++- > test/dm/reboot-mode.c | 137 ++++++++++++++++++ > 10 files changed, 595 insertions(+), 35 deletions(-) > create mode 100644 drivers/misc/qcom-spmi-sdam.c >
