[PATCH v2 2/4] dt-bindings: firmware: thead,th1520: Add resets for GPU clkgen

[Michal Wilczynski]

Extend the TH1520 AON firmware bindings to describe the GPU clkgen reset
line, required for proper GPU clock and reset sequencing.

The T-HEAD TH1520 GPU requires coordinated management of two clocks
(core and sys) and two resets (GPU core reset and GPU clkgen
reset).  Only the clkgen reset is exposed at the AON level, to support
SoC-specific initialization handled through a generic PM domain. The GPU
core reset remains described in the GPU device node, as from the GPU
driver's perspective, there is only a single reset line [1].

This follows upstream maintainers' recommendations [2] to abstract
SoC specific details into the PM domain layer rather than exposing them
to drivers directly.

[1] - https://lore.kernel.org/all/816db99d-7088-4c1a-af03-b9a825ac09dc@imgtec.com/
[2] - https://lore.kernel.org/all/38d9650fc11a674c8b689d6bab937acf@kernel.org/

Signed-off-by: Michal Wilczynski <m.wilczynski at samsung.com>
---
 .../devicetree/bindings/firmware/thead,th1520-aon.yaml        | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/Documentation/devicetree/bindings/firmware/thead,th1520-aon.yaml b/Documentation/devicetree/bindings/firmware/thead,th1520-aon.yaml
index bbc183200400de7aadbb21fea21911f6f4227b09..6ea3029c222df9ba6ea7d423b92ba248cfb02cc0 100644
--- a/Documentation/devicetree/bindings/firmware/thead,th1520-aon.yaml
+++ b/Documentation/devicetree/bindings/firmware/thead,th1520-aon.yaml
@@ -32,6 +32,13 @@ properties:
     items:
       - const: aon
 
+  resets:
+    maxItems: 1
+
+  reset-names:
+    items:
+      - const: gpu-clkgen
+
   "#power-domain-cells":
     const: 1
 
@@ -39,6 +46,8 @@ required:
   - compatible
   - mboxes
   - mbox-names
+  - resets
+  - reset-names
   - "#power-domain-cells"
 
 additionalProperties: false
@@ -49,5 +58,7 @@ examples:
         compatible = "thead,th1520-aon";
         mboxes = <&mbox_910t 1>;
         mbox-names = "aon";
+        resets = <&rst 0>;
+        reset-names = "gpu-clkgen";
         #power-domain-cells = <1>;
     };

-- 
2.34.1