[PATCH v33 3/5] dt-bindings: i2c: ast2600-i2c.yaml: Add global-regs properties

[Ryan Chen <ryan_chen@aspeedtech.com>]

Add the aspeed,global-regs phandle to reference the AST2600 global
registers syscon node, containing the SoC-common I2C register set.

These properties apply only to the AST2600 binding. Legacy DTs remain
unchanged.

Acked-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
---
Changes in v32:
- Add if/then conditional schema: when aspeed,global-regs is present,
  require reg to have at least two items. The new driver unconditionally
  maps resource index 1 (the buffer SRAM region); a DT with one reg
  entry and aspeed,global-regs passes schema validation but fails probe.
  The constraint makes the schema consistent with driver behaviour.
- Fix binding example to use the correct AST2600 clock header
  (ast2600-clock.h) and ASPEED_CLK_APB2 instead of the legacy
  aspeed-clock.h, where index 26 (ASPEED_CLK_APB) maps to the
  UART5 gate clock on AST2600 rather than the APB2 bus clock
  used by the I2C controller.

Changes in v29:
- remove aspeed,enable-dma properties.

Changes in v28:
- update commit message correspond with aspeed,enable-dma.
- remove aspeed,transfer-mode and add aspeed,enable-dma property and
  description.
- Fix aspeed,enable-dma description to reflect hardware capability rather
  than software behavior

Changes in v27:
- change aspeed,transfer-mode to aspeed,enable-dma.
---
 .../devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml   | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml b/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml
index abc614315dff..eb6e316c112f 100644
--- a/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml
+++ b/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml
@@ -48,6 +48,12 @@ properties:
   resets:
     maxItems: 1
 
+  aspeed,global-regs:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description:
+      Phandle reference to the i2c global syscon node, containing the
+      SoC-common i2c register set.
+
 required:
   - reg
   - compatible
@@ -55,19 +61,28 @@ required:
   - resets
   - interrupts
 
+if:
+  required:
+    - aspeed,global-regs
+then:
+  properties:
+    reg:
+      minItems: 2
+
 unevaluatedProperties: false
 
 examples:
   - |
-    #include <dt-bindings/clock/aspeed-clock.h>
+    #include <dt-bindings/clock/ast2600-clock.h>
     #include <dt-bindings/interrupt-controller/arm-gic.h>
     i2c@80 {
         compatible = "aspeed,ast2600-i2c-bus";
         reg = <0x80 0x80>, <0xc00 0x20>;
         #address-cells = <1>;
         #size-cells = <0>;
-        clocks = <&syscon ASPEED_CLK_APB>;
+        clocks = <&syscon ASPEED_CLK_APB2>;
         resets = <&syscon ASPEED_RESET_I2C>;
         clock-frequency = <100000>;
         interrupts = <GIC_SPI 110 IRQ_TYPE_LEVEL_HIGH>;
+        aspeed,global-regs = <&i2c_global>;
     };

-- 
2.34.1