On 06/09/2017 03:37 PM, Rob Herring wrote:

On Tue, Jun 06, 2017 at 11:45:38AM +0200, Neil Armstrong wrote:

quoted

Add bindings for the SoC information register of the Amlogic SoCs.

Signed-off-by: Neil Armstrong <redacted>
---
 Documentation/devicetree/bindings/arm/amlogic.txt | 32 +++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/amlogic.txt b/Documentation/devicetree/bindings/arm/amlogic.txt
index 5c01e65..ae3e8ed 100644
--- a/Documentation/devicetree/bindings/arm/amlogic.txt
+++ b/Documentation/devicetree/bindings/arm/amlogic.txt

@@ -60,3 +60,35 @@ Board compatible values (alphabetically, grouped by SoC):
   - "amlogic,q201" (Meson gxm s912)
   - "kingnovel,r-box-pro" (Meson gxm S912)
   - "nexbox,a1" (Meson gxm s912)
+
+Amlogic Meson Firmware registers Interface
+------------------------------------------
+
+The Meson SoCs have a register bank with status and data shared with the
+secure firmware.
+
+Required properties:
+ - compatible: For Meson GX SoCs, must be "amlogic,meson-gx-ao-secure", "syscon", "simple-mfd"
+
+Sub-nodes should indentify components of this register interface :
+
+Meson GX SoC Information
+------------------------
+A firmware register encodes the SoC type, package and revision information on
+the Meson GX SoCs.
+If present, a device node for this register should be added.
+
+Required properties:
+  - compatible: For Meson GX SoCs, must be "amlogic,meson-gx-chipid".
+
+Example
+-------
+
+ao-secure at 140 {
+	compatible = "amlogic,meson-gx-ao-secure", "syscon", "simple-mfd";
+	reg = <0x0 0x140 0x0 0x140>;
+
+	chipid {
+		compatible = "amlogic,meson-gx-chipid";

No registers for this block? If not, this node is pointless. 
"amlogic,meson-gx-ao-secure" should be specific enough to determine if 
you have this block or not and the driver for it can create a device if 
the OS needs it.

Rob

Well OK, but since it's a firmware interface, it can be handy to list the
possible capabilities, not especially tied to a driver.

Neil