reboot-mode: read the boot mode from RTC memory
RTC devices could provide battery-backed memory that can be used for
storing the reboot mode magic value.
Add a new reboot-mode back-end that uses RTC to store the reboot-mode
magic value. The driver also supports both endianness modes.
Signed-off-by: Nandor Han <nandor.han@vaisala.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/doc/device-tree-bindings/reboot-mode/reboot-mode-rtc.txt b/doc/device-tree-bindings/reboot-mode/reboot-mode-rtc.txt
new file mode 100644
index 0000000..23aa12c
--- /dev/null
+++ b/doc/device-tree-bindings/reboot-mode/reboot-mode-rtc.txt
@@ -0,0 +1,22 @@
+RTC Reboot Mode Configuration
+
+Required Properties:
+- compatible: must be "reboot-mode-rtc".
+- rtc: reference to the rtc device used.
+- reg: start register and the number of bytes used. Maximum 4 bytes supported.
+- modes: list of properties that define the modes and associated unique ids.
+
+Optional Properties:
+- u-boot,env-variable: used to save the reboot mode (default: reboot-mode).
+- big-endian: if the magic value is stored in big-endian. (default: false).
+
+Example:
+ reboot-mode-rtc {
+ compatible = "reboot-mode-rtc";
+ rtc = <&rtc_0>;
+ reg = <0x14 4>;
+ u-boot,env-variable = "bootstatus";
+ big-endian;
+ modes-test = <0x21969147>;
+ modes-download = <0x51939147>;
+ };