dt-binding: ti: am65x: document common platform time sync cpts module

Document device tree bindings for TI AM654/J721E SoC The Common Platform
Time Sync (CPTS) module. The CPTS module is used to facilitate host control
of time sync operations. Main features of CPTS module are:
  - selection of multiple external clock sources
  - 64-bit timestamp mode in ns with ppm and nudge adjustment.
  - control of time sync events via interrupt or polling
  - hardware timestamp of ext. events (HWx_TS_PUSH)
  - periodic generator function outputs (TS_GENFx)
  - PPS in combination with timesync router
  - Depending on integration it enables compliance with the IEEE 1588-2008
standard for a precision clock synchronization protocol, Ethernet Enhanced
Scheduled Traffic Operations (CPTS_ESTFn) and PCIe Subsystem Precision Time
Measurement (PTM).

Signed-off-by: Grygorii Strashko <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: grygoriyS

Documentation/devicetree/bindings/net/ti,k3-am654-cpsw-nuss.yaml

@@ -144,6 +144,13 @@ patternProperties:
     description:
       CPSW MDIO bus.
 
+  "^cpts$":
+    type: object
+    allOf:
+      - $ref: "ti,am654-cpts.yaml#"
+    description:
+      CPSW Common Platform Time Sync (CPTS) module.
+
 required:
   - compatible
   - reg

Documentation/devicetree/bindings/net/ti,k3-am654-cpts.yaml

@@ -0,0 +1,152 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/net/ti,am654-cpts.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: The TI AM654x/J721E Common Platform Time Sync (CPTS) module Device Tree Bindings
+
+maintainers:
+  - Grygorii Strashko <[email protected]>
+  - Sekhar Nori <[email protected]>
+
+description: |+
+  The TI AM654x/J721E CPTS module is used to facilitate host control of time
+  sync operations.
+  Main features of CPTS module are
+  - selection of multiple external clock sources
+  - Software control of time sync events via interrupt or polling
+  - 64-bit timestamp mode in ns with PPM and nudge adjustment.
+  - hardware timestamp push inputs (HWx_TS_PUSH)
+  - timestamp counter compare output (TS_COMP)
+  - timestamp counter bit output (TS_SYNC)
+  - periodic Generator function outputs (TS_GENFx)
+  - Ethernet Enhanced Scheduled Traffic Operations (CPTS_ESTFn) (TSN)
+  - external hardware timestamp push inputs (HWx_TS_PUSH) timestamping
+
+   Depending on integration it enables compliance with the IEEE 1588-2008
+   standard for a precision clock synchronization protocol, Ethernet Enhanced
+   Scheduled Traffic Operations (CPTS_ESTFn) and PCIe Subsystem Precision Time
+   Measurement (PTM).
+
+  TI AM654x/J721E SoCs has several similar CPTS modules integrated into the
+  different parts of the system which could be synchronized with each other
+  - Main CPTS
+  - MCU CPSW CPTS with IEEE 1588-2008 support
+  - PCIe subsystem CPTS for PTM support
+
+  Depending on CPTS module integration and when CPTS is integral part of
+  another module (MCU CPSW for example) "compatible" and "reg" can
+  be omitted - parent module is fully responsible for CPTS enabling and
+  configuration.
+
+properties:
+  $nodename:
+    pattern: "^cpts(@.*|-[0-9a-f])*$"
+
+  compatible:
+    oneOf:
+      - const: ti,am65-cpts
+      - const: ti,j721e-cpts
+
+  reg:
+    maxItems: 1
+    description:
+       The physical base address and size of CPTS IO range
+
+  reg-names:
+    items:
+      - const: cpts
+
+  clocks:
+    description: CPTS reference clock
+
+  clock-names:
+    items:
+      - const: cpts
+
+  interrupts-extended:
+    items:
+      - description: CPTS events interrupt
+
+  interrupt-names:
+    items:
+      - const: "cpts"
+
+  ti,cpts-ext-ts-inputs:
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint32
+    maximum: 8
+    description:
+        Number of hardware timestamp push inputs (HWx_TS_PUSH)
+
+  ti,cpts-periodic-outputs:
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint32
+    maximum: 8
+    description:
+         Number of timestamp Generator function outputs (TS_GENFx)
+
+  refclk-mux:
+    type: object
+    description: CPTS reference clock multiplexer clock
+    properties:
+      '#clock-cells':
+        const: 0
+
+      clocks:
+        maxItems: 8
+
+      assigned-clocks:
+        maxItems: 1
+
+      assigned-clocks-parents:
+        maxItems: 1
+
+    required:
+      - clocks
+
+required:
+  - clocks
+  - clock-names
+  - interrupts-extended
+  - interrupt-names
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+    cpts@310d0000 {
+         compatible = "ti,am65-cpts";
+         reg = <0x0 0x310d0000 0x0 0x400>;
+         reg-names = "cpts";
+         clocks = <&main_cpts_mux>;
+         clock-names = "cpts";
+         interrupts-extended = <&k3_irq 163 0 IRQ_TYPE_LEVEL_HIGH>;
+         interrupt-names = "cpts";
+         ti,cpts-periodic-outputs = <6>;
+         ti,cpts-ext-ts-inputs = <8>;
+
+         main_cpts_mux: refclk-mux {
+               #clock-cells = <0>;
+               clocks = <&k3_clks 118 5>, <&k3_clks 118 11>,
+                        <&k3_clks 157 91>, <&k3_clks 157 77>,
+                        <&k3_clks 157 102>, <&k3_clks 157 80>,
+                        <&k3_clks 120 3>, <&k3_clks 121 3>;
+               assigned-clocks = <&main_cpts_mux>;
+               assigned-clock-parents = <&k3_clks 118 11>;
+         };
+    };
+  - |
+
+    cpts {
+             clocks = <&k3_clks 18 2>;
+             clock-names = "cpts";
+             interrupts-extended = <&gic500 GIC_SPI 858 IRQ_TYPE_LEVEL_HIGH>;
+             interrupt-names = "cpts";
+             ti,cpts-ext-ts-inputs = <4>;
+             ti,cpts-periodic-outputs = <2>;
+    };