1*c66ec88fSEmmanuel Vadot* Amlogic Virtual RTC (VRTC) 2*c66ec88fSEmmanuel Vadot 3*c66ec88fSEmmanuel VadotThis is a Linux interface to an RTC managed by firmware, hence it's 4*c66ec88fSEmmanuel Vadotvirtual from a Linux perspective. The interface is 1 register where 5*c66ec88fSEmmanuel Vadotan alarm time (in seconds) is to be written. 6*c66ec88fSEmmanuel Vadot 7*c66ec88fSEmmanuel VadotRequired properties: 8*c66ec88fSEmmanuel Vadot- compatible: should be "amlogic,meson-vrtc" 9*c66ec88fSEmmanuel Vadot- reg: physical address for the alarm register 10*c66ec88fSEmmanuel Vadot 11*c66ec88fSEmmanuel VadotThe alarm register is a simple scratch register shared between the 12*c66ec88fSEmmanuel Vadotapplication processors (AP) and the secure co-processor (SCP.) When 13*c66ec88fSEmmanuel Vadotthe AP suspends, the SCP will use the value of this register to 14*c66ec88fSEmmanuel Vadotprogram an always-on timer before going sleep. When the timer expires, 15*c66ec88fSEmmanuel Vadotthe SCP will wake up and will then wake the AP. 16*c66ec88fSEmmanuel Vadot 17*c66ec88fSEmmanuel VadotExample: 18*c66ec88fSEmmanuel Vadot 19*c66ec88fSEmmanuel Vadot vrtc: rtc@0a8 { 20*c66ec88fSEmmanuel Vadot compatible = "amlogic,meson-vrtc"; 21*c66ec88fSEmmanuel Vadot reg = <0x0 0x000a8 0x0 0x4>; 22*c66ec88fSEmmanuel Vadot }; 23