This patchset extends on Andy Yan's reboot mode driver work from here: https://lkml.org/lkml/2016/1/12/315
It adds reboot mode/reason support for devices that use an SRAM location to communicate with the bootloader. Doing this via an SRAM subnode was a suggestion from Arnd, but I worry this implementation isn't yet ideal, since I spent quite a bit of time futzing with getting the sram dts entry to work properly. So I suspect there will be a number of suggestions for improvements. Again, this series dependson Andy's patch set above, but also was developed & tested against the 4.1 based hikey tree, so at least the hikey dts patch won't apply. I'm mostly sending this out for just a rough initial review of the dts and conceptual usage of sram subnodes. Also, it was pointed out that the hikey dts entry for this really should be added by the UEFI firmware, since alternative bootloaders may be used which do not support this feature. So the hikey dts patch isn't likely to ever go upstream, but its a useful illustration for how other devices might use this driver. Cc: Andy Yan <[email protected]> Cc: Rob Herring <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Thierry Reding <[email protected]> Cc: Heiko Stübner <[email protected]> Cc: Caesar Wang <[email protected]> Cc: Kees Cook <[email protected]> Cc: Guodong Xu <[email protected]> Cc: Haojian Zhuang <[email protected]> Cc: Vishal Bhoj <[email protected]> Cc: Bjorn Andersson <[email protected]> Cc: [email protected] Cc: Android Kernel Team <[email protected]> John Stultz (3): dt-bindings: power: reset: Add document for sram-reboot-mode driver power: reset: Add sram-reboot-mode driver dts: hikey: Add hikey support for sram-reboot-mode .../bindings/power/reset/sram-reboot-mode.txt | 47 +++++++++++++++ arch/arm64/boot/dts/hisilicon/hi6220-hikey.dts | 36 ++++++++++++ arch/arm64/configs/hikey_defconfig | 3 + drivers/power/reset/Kconfig | 9 +++ drivers/power/reset/Makefile | 1 + drivers/power/reset/sram-reboot-mode.c | 66 ++++++++++++++++++++++ 6 files changed, 162 insertions(+) create mode 100644 Documentation/devicetree/bindings/power/reset/sram-reboot-mode.txt create mode 100644 drivers/power/reset/sram-reboot-mode.c -- 1.9.1
