Add DT bindings to configurate the PMC_FSMR and PMC_FSPR registers
to trigger a fast restart signal to PMC.

Signed-off-by: Wenyou Yang <redacted>
---

Changes in v2:
 - change the property name and property description.

 .../devicetree/bindings/arm/atmel-pmc.txt          |   63 ++++++++++++++++++++
 1 file changed, 63 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/atmel-pmc.txt b/Documentation/devicetree/bindings/arm/atmel-pmc.txt
index 795cc78..1b3833b 100644
--- a/Documentation/devicetree/bindings/arm/atmel-pmc.txt
+++ b/Documentation/devicetree/bindings/arm/atmel-pmc.txt

@@ -12,3 +12,66 @@ Examples:
 		compatible = "atmel,at91rm9200-pmc";
 		reg = <0xfffffc00 0x100>;
 	};
+
+PMC Fast Startup Signals
+
+The PMC Fast Start Signals are used as the wake up source to trigger the PMC
+to wake up the system from the ULP1 mode.
+
+required properties:
+- compatible: Should be "atmel,sama5d2-pmc-fast-startup".
+
+optional properties:
+- atmel,wkup-trigger: boolean, WKUP input can trigger a fast restart signal.
+- atmel,secumod-trigger: boolean, SECUMOD can trigger a fast restart signal.
+- atmel,piobu0-trigger: boolean, PIOBU0 input can trigger a fast restart signal.
+- atmel,piobu1-trigger: boolean, PIOBU1 input can trigger a fast restart signal.
+- atmel,piobu2-trigger: boolean, PIOBU2 input can trigger a fast restart signal.
+- atmel,piobu3-trigger: boolean, PIOBU3 input can trigger a fast restart signal.
+- atmel,piobu4-trigger: boolean, PIOBU4 input can trigger a fast restart signal.
+- atmel,piobu5-trigger: boolean, PIOBU5 input can trigger a fast restart signal.
+- atmel,piobu6-trigger: boolean, PIOBU6 input can trigger a fast restart signal.
+- atmel,piobu7-trigger: boolean, PIOBU7 input can trigger a fast restart signal.
+- atmel,gmac-wol-trigger: boolean, GMAC_WOL can trigger a fast restart signal.
+- atmel,rtc-alarm-trigger: boolean, RTC alarm can trigger a fast restart signal.
+- atmel,usb-resume-trigger: boolean, USB resume can trigger a fast restart
+  signal.
+- atmel,sdmmc-cd-trigger: boolean, SDMMC card detect can trigger a fast
+  restart signal.
+- atmel,rxlp-match-trigger: boolean, Matching condition on RXLP can trigger
+  a fast restart signal.
+- atmel,acc-comparison-trigger: boolean, ACC comparison can trigger a fast
+  restart signal.
+
+- atmel,wkup-trigger-level: string, defines the active polarity of the wake-up
+  input. Supported values are: "high" or "low".