NXP NETC (Ethernet Controller) is a multi-function PCIe Root Complex
Integrated Endpoint (RCiEP), the Timer is one of its functions which
provides current time with nanosecond resolution, precise periodic
pulse, pulse on timeout (alarm), and time capture on external pulse
support. And also supports time synchronization as required for IEEE
1588 and IEEE 802.1AS-2020. So add device tree binding doc for the
PTP clock based on NETC Timer.

Signed-off-by: Wei Fang <wei.fang@nxp.com>

---
v2 changes:
1. Refine the subject and the commit message
2. Remove "nxp,pps-channel"
3. Add description to "clocks" and "clock-names"
---
 .../devicetree/bindings/ptp/nxp,ptp-netc.yaml | 67 +++++++++++++++++++
 1 file changed, 67 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/ptp/nxp,ptp-netc.yaml

diff --git a/Documentation/devicetree/bindings/ptp/nxp,ptp-netc.yaml b/Documentation/devicetree/bindings/ptp/nxp,ptp-netc.yaml
new file mode 100644
index 000000000000..6af1899d904f
--- /dev/null
+++ b/Documentation/devicetree/bindings/ptp/nxp,ptp-netc.yaml
@@ -0,0 +1,67 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/ptp/nxp,ptp-netc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NXP NETC Timer PTP clock
+
+description:
+  NETC Timer provides current time with nanosecond resolution, precise
+  periodic pulse, pulse on timeout (alarm), and time capture on external
+  pulse support. And it supports time synchronization as required for
+  IEEE 1588 and IEEE 802.1AS-2020.
+
+maintainers:
+  - Wei Fang <wei.fang@nxp.com>
+  - Clark Wang <xiaoning.wang@nxp.com>
+
+properties:
+  compatible:
+    enum:
+      - pci1131,ee02
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+    description:
+      The reference clock of NETC Timer, if not present, indicates that
+      the system clock of NETC IP is selected as the reference clock.
+
+  clock-names:
+    description:
+      NETC Timer has three reference clock sources, set TMR_CTRL[CK_SEL]
+      by parsing clock name to select one of them as the reference clock.
+      The "system" means that the system clock of NETC IP is used as the
+      reference clock.
+      The "ccm_timer" means another clock from CCM as the reference clock.
+      The "ext_1588" means the reference clock comes from external IO pins.
+    enum:
+      - system
+      - ccm_timer
+      - ext_1588
+
+required:
+  - compatible
+  - reg
+
+allOf:
+  - $ref: /schemas/pci/pci-device.yaml
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    pcie {
+        #address-cells = <3>;
+        #size-cells = <2>;
+
+        ethernet@18,0 {
+            compatible = "pci1131,ee02";
+            reg = <0x00c000 0 0 0 0>;
+            clocks = <&scmi_clk 18>;
+            clock-names = "ccm_timer";
+        };
+    };
-- 
2.34.1