dt-bindings: phy: spacemit: Introduce PCIe PHY

Add the Device Tree binding for two PCIe PHYs present on the SpacemiT
K1 SoC.  These PHYs are dependent on a separate combo PHY, which
determines at probe time the calibration values used by the PCIe-only
PHYs.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Alex Elder <elder@riscstar.com>
Link: https://lore.kernel.org/all/ba532f8d-a452-40e5-af46-b58b89f70a92@linaro.org/ [1]
Tested-by: Yixun Lan <dlan@gentoo.org>
Link: https://patch.msgid.link/20251218151235.454997-3-elder@riscstar.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

1 files changed, 71 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/phy/spacemit,k1-pcie-phy.yaml b/Documentation/devicetree/bindings/phy/spacemit,k1-pcie-phy.yaml
new file mode 100644
index 000000000000..019b28349be7
--- /dev/null
+++ b/Documentation/devicetree/bindings/phy/spacemit,k1-pcie-phy.yaml
@@ -0,0 +1,71 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/phy/spacemit,k1-pcie-phy.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: SpacemiT K1 PCIe PHY
+
+maintainers:
+  - Alex Elder <elder@riscstar.com>
+
+description: >
+  Two PHYs on the SpacemiT K1 SoC used for only for PCIe.  These
+  PHYs must be configured using calibration values that are
+  determined by a third "combo PHY".  The combo PHY determines
+  these calibration values during probe so they can be used for
+  the two PCIe-only PHYs.
+
+  The PHY uses an external oscillator as a reference clock.  During
+  normal operation, the PCIe host driver is responsible for ensuring
+  all other clocks needed by a PHY are enabled, and all resets
+  affecting the PHY are deasserted.
+
+properties:
+  compatible:
+    const: spacemit,k1-pcie-phy
+
+  reg:
+    items:
+      - description: PHY control registers
+
+  clocks:
+    items:
+      - description: External oscillator used by the PHY PLL
+
+  clock-names:
+    const: refclk
+
+  resets:
+    items:
+      - description: PHY reset; remains deasserted after initialization
+
+  reset-names:
+    const: phy
+
+  "#phy-cells":
+    const: 0
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - resets
+  - reset-names
+  - "#phy-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/spacemit,k1-syscon.h>
+    phy@c0c10000 {
+        compatible = "spacemit,k1-pcie-phy";
+        reg = <0xc0c10000 0x1000>;
+        clocks = <&vctcxo_24m>;
+        clock-names = "refclk";
+        resets = <&syscon_apmu RESET_PCIE1_GLOBAL>;
+        reset-names = "phy";
+        #phy-cells = <0>;
+    };