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authorNandor Han <nandor.han@vaisala.com>2021-06-10 16:56:45 +0300
committerTom Rini <trini@konsulko.com>2021-07-23 17:16:39 +0300
commitc74675bd904b6ce9d5820a80f27793c0583fd54c (patch)
treeb9b6e93ebe0d54334e3bf96b70e6a556a01a0f7c /doc/device-tree-bindings
parentf9db2f16cb6fc7b6d05b0e70de65881bc97ba5c2 (diff)
downloadu-boot-c74675bd904b6ce9d5820a80f27793c0583fd54c.tar.xz
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>
Diffstat (limited to 'doc/device-tree-bindings')
-rw-r--r--doc/device-tree-bindings/reboot-mode/reboot-mode-rtc.txt22
1 files changed, 22 insertions, 0 deletions
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 0000000000..23aa12c88c
--- /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>;
+ };