Linux dts how tos

Sleep and RTC wakeup

This is a customer contribute posted on the Acme Systems newsgroup

Finally my Berta A5 board is correctly going in sleep mode with automatic RTC wakeup. Maybe someone using Acqua A5 could find this usefull.

First, using kernel 3.10+ (supplied with uSD card from AcmeSystems but also with compiled 3.10 kernel) at shutdown SHDN terminal keeps at 3,3 volt. This due to missing code about shutdown controller register into arch/arm/boot/dts/sama5d3.dtsi file.

     reg = <0xfffffe00 0x10>;

+   shutdown-controller@fffffe10 {
+       compatible = "atmel,at91sam9x5-shdwc";
+       reg = <0xfffffe10 0x10>;
+   };

    pit: timer@fffffe30 {
        compatible = "atmel,at91sam9260-pit";
        reg = <0xfffffe30 0xf>;