dt-bindings: net: Add bindings for IXP4xx V.35 WAN HSS

This adds device tree bindings for the IXP4xx V.35 WAN high
speed serial (HSS) link.

An example is added to the NPE example where the HSS appears
as a child.

Cc: devicetree@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/firmware/intel,ixp4xx-network-processing-engine.yaml

@@ -37,6 +37,20 @@ properties:
       should be named with the instance number of the NPE engine used for
       the crypto engine.
 
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+patternProperties:
+  hss@[0-9]+$:
+    $ref: /schemas/net/intel,ixp4xx-hss.yaml#
+    type: object
+    description: Optional node for the High Speed Serial link (HSS), the
+      node should be named with the instance number of the NPE engine
+      used for the HSS.
+
 required:
   - compatible
   - reg
@@ -45,9 +59,30 @@ additionalProperties: false
 
 examples:
   - |
+    #include <dt-bindings/gpio/gpio.h>
+
     npe: npe@c8006000 {
          compatible = "intel,ixp4xx-network-processing-engine";
          reg = <0xc8006000 0x1000>, <0xc8007000 0x1000>, <0xc8008000 0x1000>;
+         #address-cells = <1>;
+         #size-cells = <0>;
+
+         hss@0 {
+             compatible = "intel,ixp4xx-hss";
+             reg = <0>;
+             intel,npe-handle = <&npe 0>;
+             intel,queue-chl-rxtrig = <&qmgr 12>;
+             intel,queue-chl-txready = <&qmgr 34>;
+             intel,queue-pkt-rx = <&qmgr 13>;
+             intel,queue-pkt-tx = <&qmgr 14>, <&qmgr 15>, <&qmgr 16>, <&qmgr 17>;
+             intel,queue-pkt-rxfree = <&qmgr 18>, <&qmgr 19>, <&qmgr 20>, <&qmgr 21>;
+             intel,queue-pkt-txdone = <&qmgr 22>;
+             cts-gpios = <&gpio0 10 GPIO_ACTIVE_LOW>;
+             rts-gpios = <&gpio0 14 GPIO_ACTIVE_LOW>;
+             dcd-gpios = <&gpio0 6 GPIO_ACTIVE_LOW>;
+             dtr-gpios = <&gpio_74 2 GPIO_ACTIVE_LOW>;
+             clk-internal-gpios = <&gpio_74 0 GPIO_ACTIVE_HIGH>;
+         };
 
          crypto {
              compatible = "intel,ixp4xx-crypto";

Documentation/devicetree/bindings/net/intel,ixp4xx-hss.yaml

@@ -0,0 +1,100 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+# Copyright 2021 Linaro Ltd.
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/net/intel,ixp4xx-hss.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: Intel IXP4xx V.35 WAN High Speed Serial Link (HSS)
+
+maintainers:
+  - Linus Walleij <linus.walleij@linaro.org>
+
+description: |
+  The Intel IXP4xx HSS makes use of the IXP4xx NPE (Network
+  Processing Engine) and the IXP4xx Queue Manager to process
+  V.35 Wideband Modem (WAN) links.
+
+properties:
+  compatible:
+    const: intel,ixp4xx-hss
+
+  reg:
+    maxItems: 1
+    description: The HSS instance
+
+  intel,npe-handle:
+    $ref: '/schemas/types.yaml#/definitions/phandle-array'
+    maxItems: 1
+    description: phandle to the NPE this HSS instance is using
+      and the instance to use in the second cell
+
+  intel,queue-chl-rxtrig:
+    $ref: '/schemas/types.yaml#/definitions/phandle-array'
+    maxItems: 1
+    description: phandle to the RX trigger queue on the NPE
+
+  intel,queue-chl-txready:
+    $ref: '/schemas/types.yaml#/definitions/phandle-array'
+    maxItems: 1
+    description: phandle to the TX ready queue on the NPE
+
+  intel,queue-pkt-rx:
+    $ref: '/schemas/types.yaml#/definitions/phandle-array'
+    maxItems: 1
+    description: phandle to the packet RX queue on the NPE
+
+  intel,queue-pkt-tx:
+    $ref: '/schemas/types.yaml#/definitions/phandle-array'
+    maxItems: 4
+    description: phandle to the packet TX0, TX1, TX2 and TX3 queues on the NPE
+
+  intel,queue-pkt-rxfree:
+    $ref: '/schemas/types.yaml#/definitions/phandle-array'
+    maxItems: 4
+    description: phandle to the packet RXFREE0, RXFREE1, RXFREE2 and
+      RXFREE3 queues on the NPE
+
+  intel,queue-pkt-txdone:
+    $ref: '/schemas/types.yaml#/definitions/phandle-array'
+    maxItems: 1
+    description: phandle to the packet TXDONE queue on the NPE
+
+  cts-gpios:
+    maxItems: 1
+    description: Clear To Send (CTS) GPIO line
+
+  rts-gpios:
+    maxItems: 1
+    description: Ready To Send (RTS) GPIO line
+
+  dcd-gpios:
+    maxItems: 1
+    description: Data Carrier Detect (DCD) GPIO line
+
+  dtr-gpios:
+    maxItems: 1
+    description: Data Terminal Ready (DTR) GPIO line
+
+  clk-internal-gpios:
+    maxItems: 1
+    description: Clock internal GPIO line, driving this high will make the HSS
+      use internal clocking as opposed to external clocking
+
+required:
+  - compatible
+  - reg
+  - intel,npe-handle
+  - intel,queue-chl-rxtrig
+  - intel,queue-chl-txready
+  - intel,queue-pkt-rx
+  - intel,queue-pkt-tx
+  - intel,queue-pkt-rxfree
+  - intel,queue-pkt-txdone
+  - cts-gpios
+  - rts-gpios
+  - dcd-gpios
+  - dtr-gpios
+  - clk-internal-gpios
+
+additionalProperties: false