[PATCH 1/2] dt-bindings: wkup-m3-ipc: Add vtt toggle bindings

[Drew Fustini <dfustini@baylibre.com>]

Document the Wakeup M3 IPC properties that can be used to toggle the VTT
regulator during low power mode transitions.

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
[dfustini: converted to YAML]
Signed-off-by: Drew Fustini <dfustini@baylibre.com>
---
 .../bindings/soc/ti/wkup-m3-ipc.yaml          | 21 +++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/Documentation/devicetree/bindings/soc/ti/wkup-m3-ipc.yaml b/Documentation/devicetree/bindings/soc/ti/wkup-m3-ipc.yaml
index d855c01ce61c..6a8fcad8b2fd 100644
--- a/Documentation/devicetree/bindings/soc/ti/wkup-m3-ipc.yaml
+++ b/Documentation/devicetree/bindings/soc/ti/wkup-m3-ipc.yaml
@@ -24,6 +24,16 @@ description: |+
   A wkup_m3_ipc device node is used to represent the IPC registers within an
   SoC.
 
+  Support for VTT Toggle
+  ==================================
+  In order to enable the support for VTT toggle during Suspend/Resume sequence
+  needed by some boards (like AM335x EVM-SK & AM437x GP EVM), the vtt properties
+  below are required. It is possible to toggle VTT using one of two methods
+  depending on the SoC being used, either GPIO0 toggle (AM335x and AM437x), or
+  any GPIO with DS_PAD_CONFIG bits in the control module (AM437x only). Please
+  note that only pins on the GPIO0 module can be used for GPIO toggle. It will
+  not work with any other GPIO module.
+
 properties:
   compatible:
     enum:
@@ -51,6 +61,15 @@ properties:
       mbox_wkupm3 child node.
     maxItems: 1
 
+  ti,needs-vtt-toggle:
+    type: boolean
+    description: boards requires VTT toggling during suspend/resume
+
+  ti,vtt-gpio-pin:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: pin on the GPIO0 module used for VTT toggle
+    maxItems: 1
+
 required:
   - compatible
   - reg
@@ -76,6 +95,8 @@ examples:
            interrupts = <78>;
            ti,rproc = <&wkup_m3>;
            mboxes = <&mailbox &mbox_wkupm3>;
+           ti,needs-vtt-toggle;
+           ti,vtt-gpio-pin = <7>;
         };
     };
 ...
-- 
2.32.0