[PATCH v3 08/12] dt-bindings: phy: Add PCIe PHY support for FSD SoC

[Shradha Todi <shradha.t@xxxxxxxxxxx>]

Since Tesla FSD SoC uses Samsung PCIe PHY, add support in
exynos PCIe PHY bindings.

In Tesla FSD SoC, the two PHY instances, although having identical
hardware design and register maps, are placed in different locations
(Placement and routing) inside the SoC and have distinct
PHY-to-Controller topologies. (One instance is connected to two PCIe
controllers, while the other is connected to only one). As a result,
they experience different analog environments, including varying
channel losses and noise profiles.

Since these PHYs lack internal adaptation mechanisms and f/w based
tuning, manual register programming is required for analog tuning.
To ensure optimal signal integrity, it is essential to use different
register values for each PHY instance, despite their identical hardware
design. This is because the same register values may not be suitable
for both instances due to their differing environments and topologies.

Due to this, we are using two PHY compatibles for different PHY
instances.

Signed-off-by: Shradha Todi <shradha.t@xxxxxxxxxxx>
---
 .../bindings/phy/samsung,exynos-pcie-phy.yaml | 27 +++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/phy/samsung,exynos-pcie-phy.yaml b/Documentation/devicetree/bindings/phy/samsung,exynos-pcie-phy.yaml
index 41df8bb08ff7..6295472696db 100644
--- a/Documentation/devicetree/bindings/phy/samsung,exynos-pcie-phy.yaml
+++ b/Documentation/devicetree/bindings/phy/samsung,exynos-pcie-phy.yaml
@@ -15,10 +15,14 @@ properties:
     const: 0
 
   compatible:
-    const: samsung,exynos5433-pcie-phy
+    enum:
+      - samsung,exynos5433-pcie-phy
+      - tesla,fsd-pcie-phy0
+      - tesla,fsd-pcie-phy1
 
   reg:
-    maxItems: 1
+    minItems: 1
+    maxItems: 2
 
   samsung,pmu-syscon:
     $ref: /schemas/types.yaml#/definitions/phandle
@@ -30,6 +34,25 @@ properties:
     description: phandle for FSYS sysreg interface, used to control
                  sysreg registers bits for PCIe PHY
 
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - tesla,fsd-pcie-phy0
+              - tesla,fsd-pcie-phy1
+    then:
+      properties:
+        reg:
+          items:
+            - description: PHY
+            - description: PCS
+    else:
+      properties:
+        reg:
+          maxItems: 1
+
 required:
   - "#phy-cells"
   - compatible
-- 
2.49.0