[PATCH v4] dt-bindings: pinctrl: renesas: Document RZ/V2H(P) SoC

[Prabhakar]

From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>

Add documentation for the pin controller found on the Renesas RZ/V2H(P)
(R9A09G057) SoC. The RZ/V2H PFC varies slightly compared to the RZ/G2L
family:
- Additional bits need to be set during pinmuxing.
- The GPIO pin count is different.

Hence, a SoC-specific compatible string, 'renesas,r9a09g057-pinctrl', is
added for the RZ/V2H(P) SoC.

Also, add the 'renesas,output-impedance' property. The drive strength
setting on RZ/V2H(P) depends on the different power rails coming out from
the PMIC (connected via I2C). These power rails (required for drive
strength) can be 1.2V, 1.8V, or 3.3V.

Pins are grouped into 4 groups:

Group 1: Impedance
- 150/75/38/25 ohms (at 3.3V)
- 130/65/33/22 ohms (at 1.8V)

Group 2: Impedance
- 50/40/33/25 ohms (at 1.8V)

Group 3: Impedance
- 150/75/37.5/25 ohms (at 3.3V)
- 130/65/33/22 ohms (at 1.8V)

Group 4: Impedance
- 110/55/30/20 ohms (at 1.8V)
- 150/75/38/25 ohms (at 1.2V)

The 'renesas,output-impedance' property, as documented, can be
[0, 1, 2, 3], these correspond to register bit values that can
be set in the PFC_IOLH_mn register, which adjusts the drive
strength value and is pin-dependent.

As power rail information may not be available very early in the boot
process, the 'renesas,output-impedance' property is added instead of
reusing the 'output-impedance-ohms' property.

Also, allow bias-disable, bias-pull-down and bias-pull-up properties
as these can be used to configure the pins.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
---
Sending just the binding patch of series [0] as reset of the patches have
been Reviewed.

[0] https://patchwork.kernel.org/project/linux-renesas-soc/cover/20240530173857.164073-1-prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx/

v3->v4
- Added a conditional schema for ensuring the reset length
  is 2 for RZ/V2H and 3 otherwise
- Updated description for renesas,output-impedance property
- Dropped '|'

v2->v3
- Updated description for renesas,output-impedance property
- Updated commit description

RFC->v2
- Renamed renesas-rzv2h,output-impedance -> renesas,output-impedance
- Updated values for renesas,output-impedance
- Added bias properties
---
 .../pinctrl/renesas,rzg2l-pinctrl.yaml        | 37 +++++++++++++++++--
 1 file changed, 33 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/pinctrl/renesas,rzg2l-pinctrl.yaml b/Documentation/devicetree/bindings/pinctrl/renesas,rzg2l-pinctrl.yaml
index 881e992adca3..56d90c8e1fa3 100644
--- a/Documentation/devicetree/bindings/pinctrl/renesas,rzg2l-pinctrl.yaml
+++ b/Documentation/devicetree/bindings/pinctrl/renesas,rzg2l-pinctrl.yaml
@@ -26,6 +26,7 @@ properties:
               - renesas,r9a07g043-pinctrl # RZ/G2UL{Type-1,Type-2} and RZ/Five
               - renesas,r9a07g044-pinctrl # RZ/G2{L,LC}
               - renesas,r9a08g045-pinctrl # RZ/G3S
+              - renesas,r9a09g057-pinctrl # RZ/V2H(P)
 
       - items:
           - enum:
@@ -66,10 +67,14 @@ properties:
     maxItems: 1
 
   resets:
-    items:
-      - description: GPIO_RSTN signal
-      - description: GPIO_PORT_RESETN signal
-      - description: GPIO_SPARE_RESETN signal
+    oneOf:
+      - items:
+          - description: GPIO_RSTN signal
+          - description: GPIO_PORT_RESETN signal
+          - description: GPIO_SPARE_RESETN signal
+      - items:
+          - description: PFC main reset
+          - description: Reset for the control register related to WDTUDFCA and WDTUDFFCM pins
 
 additionalProperties:
   anyOf:
@@ -111,6 +116,16 @@ additionalProperties:
         output-high: true
         output-low: true
         line-name: true
+        bias-disable: true
+        bias-pull-down: true
+        bias-pull-up: true
+        renesas,output-impedance:
+          description:
+            Output impedance for pins on the RZ/V2H(P) SoC. The value provided by this
+            property corresponds to register bit values that can be set in the PFC_IOLH_mn
+            register, which adjusts the drive strength value and is pin-dependent.
+          $ref: /schemas/types.yaml#/definitions/uint32
+          enum: [0, 1, 2, 3]
 
     - type: object
       additionalProperties:
@@ -119,6 +134,20 @@ additionalProperties:
 allOf:
   - $ref: pinctrl.yaml#
 
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: renesas,r9a09g057-pinctrl
+    then:
+      properties:
+        resets:
+          maxItems: 2
+    else:
+      properties:
+        resets:
+          minItems: 3
+
 required:
   - compatible
   - reg
-- 
2.34.1