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authorKevin Hilman <khilman@baylibre.com>2019-08-12 16:28:49 -0700
committerAlexandre Belloni <alexandre.belloni@bootlin.com>2019-08-22 23:08:30 +0200
commited16239637f6656d3e6656ed1753e70d7823d94f (patch)
tree0ed1d45c35f9ddfbe185870ba7134d31bd4dc776 /Documentation/devicetree/bindings/rtc
parenta6f26606ddd03c5eab8b2132f1bfaa768c06158f (diff)
dt-bindings: rtc: new binding for Amlogic VRTC
Add binding fo the new VRTC driver for Amlogic SoCs. The 64-bit family of SoCs only has an RTC managed by firmware, and this VRTC driver provides the simple, one-register firmware interface. Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Kevin Hilman <khilman@baylibre.com> Link: https://lore.kernel.org/r/20190812232850.8016-2-khilman@kernel.org Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Diffstat (limited to 'Documentation/devicetree/bindings/rtc')
-rw-r--r--Documentation/devicetree/bindings/rtc/rtc-meson-vrtc.txt22
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diff --git a/Documentation/devicetree/bindings/rtc/rtc-meson-vrtc.txt b/Documentation/devicetree/bindings/rtc/rtc-meson-vrtc.txt
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+++ b/Documentation/devicetree/bindings/rtc/rtc-meson-vrtc.txt
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+* Amlogic Virtual RTC (VRTC)
+
+This is a Linux interface to an RTC managed by firmware, hence it's
+virtual from a Linux perspective. The interface is 1 register where
+an alarm time (in seconds) is to be written.
+
+Required properties:
+- compatible: should be "amlogic,meson-vrtc"
+- reg: physical address for the alarm register
+
+The alarm register is a simple scratch register shared between the
+application processors (AP) and the secure co-processor (SCP.) When
+the AP suspends, the SCP will use the value of this register to
+program an always-on timer before going sleep. When the timer expires,
+the SCP will wake up and will then wake the AP.
+
+Example:
+
+ vrtc: rtc@0a8 {
+ compatible = "amlogic,meson-vrtc";
+ reg = <0x0 0x000a8 0x0 0x4>;
+ };