18c2ecf20Sopenharmony_ci* Amlogic Virtual RTC (VRTC)
28c2ecf20Sopenharmony_ci
38c2ecf20Sopenharmony_ciThis is a Linux interface to an RTC managed by firmware, hence it's
48c2ecf20Sopenharmony_civirtual from a Linux perspective.  The interface is 1 register where
58c2ecf20Sopenharmony_cian alarm time (in seconds) is to be written.
68c2ecf20Sopenharmony_ci
78c2ecf20Sopenharmony_ciRequired properties:
88c2ecf20Sopenharmony_ci- compatible: should be "amlogic,meson-vrtc"
98c2ecf20Sopenharmony_ci- reg: physical address for the alarm register
108c2ecf20Sopenharmony_ci
118c2ecf20Sopenharmony_ciThe alarm register is a simple scratch register shared between the
128c2ecf20Sopenharmony_ciapplication processors (AP) and the secure co-processor (SCP.)  When
138c2ecf20Sopenharmony_cithe AP suspends, the SCP will use the value of this register to
148c2ecf20Sopenharmony_ciprogram an always-on timer before going sleep. When the timer expires,
158c2ecf20Sopenharmony_cithe SCP will wake up and will then wake the AP.
168c2ecf20Sopenharmony_ci
178c2ecf20Sopenharmony_ciExample:
188c2ecf20Sopenharmony_ci
198c2ecf20Sopenharmony_ci	vrtc: rtc@0a8 {
208c2ecf20Sopenharmony_ci		compatible = "amlogic,meson-vrtc";
218c2ecf20Sopenharmony_ci		reg = <0x0 0x000a8 0x0 0x4>;
228c2ecf20Sopenharmony_ci	};
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