Add dt-bindings for Aspeed UART routing controller.
Signed-off-by: Oskar Senft <osk@xxxxxxxxxx>
Signed-off-by: Chia-Wei Wang <chiawei_wang@xxxxxxxxxxxxxx>
---
.../devicetree/bindings/mfd/aspeed-lpc.yaml | 4 ++
.../bindings/soc/aspeed/uart-routing.yaml | 70 +++++++++++++++++++
2 files changed, 74 insertions(+)
create mode 100644 Documentation/devicetree/bindings/soc/aspeed/uart-routing.yaml
diff --git a/Documentation/devicetree/bindings/mfd/aspeed-lpc.yaml b/Documentation/devicetree/bindings/mfd/aspeed-lpc.yaml
index 4e3862cf2a4b..f9aa431127ee 100644
--- a/Documentation/devicetree/bindings/mfd/aspeed-lpc.yaml
+++ b/Documentation/devicetree/bindings/mfd/aspeed-lpc.yaml
@@ -142,6 +142,10 @@ patternProperties:
- interrupts
- snoop-ports
+ "^uart-routing@[0-9a-f]+$":
+ $ref: /schemas/soc/aspeed/uart-routing.yaml#
+ description: The UART routing control under LPC register space
+
required:
- compatible
- reg
diff --git a/Documentation/devicetree/bindings/soc/aspeed/uart-routing.yaml b/Documentation/devicetree/bindings/soc/aspeed/uart-routing.yaml
new file mode 100644
index 000000000000..534b2a9340ce
--- /dev/null
+++ b/Documentation/devicetree/bindings/soc/aspeed/uart-routing.yaml
@@ -0,0 +1,70 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# # Copyright (c) 2018 Google LLC
+# # Copyright (c) 2021 Aspeed Technology Inc.
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/soc/aspeed/uart-routing.yaml#";
+$schema: "http://devicetree.org/meta-schemas/core.yaml#";
+
+title: Aspeed UART Routing Controller
+
+maintainers:
+ - Oskar Senft <osk@xxxxxxxxxx>
+ - Chia-Wei Wang <chiawei_wang@xxxxxxxxxxxxxx>
+
+description:
+ The Aspeed UART routing control allow to dynamically route the inputs for
+ the built-in UARTS and physical serial I/O ports.
+
+ This allows, for example, to connect the output of UART to another UART.
+ This can be used to enable Host <-> BMC communication via UARTs, e.g. to
+ allow access to the Host's serial console.
+
+ This driver is for the BMC side. The sysfs files allow the BMC userspace
+ which owns the system configuration policy, to configure how UARTs and
+ physical serial I/O ports are routed.
+
+ Two types of files, uart* and io*, are presented in sysfs. The uart*
+ configures the input signal of a UART controller whereas io* configures
+ that of a physical serial port.
+
+ When read, each file shows the list of available options with currently
+ selected option marked by brackets "[]". The list of available options
+ depends on the selected file.
+
+ e.g.
+ cat /sys/bus/platform/drivers/aspeed-uart-routing/*.uart_routing/uart1
+ [io1] io2 io3 io4 uart2 uart3 uart4 io6
+
+ In this case, UART1 gets its input from IO1 (physical serial port 1).
+
+properties:
+ compatible:
+ items:
+ - enum:
+ - aspeed,ast2400-uart-routing
+ - aspeed,ast2500-uart-routing
+ - aspeed,ast2600-uart-routing
+ reg:
+ maxItems: 1
+
+required:
+ - compatible
+
+additionalProperties: false
+
+examples:
+ - |
+ lpc: lpc@1e789000 {
+ compatible = "aspeed,ast2600-lpc-v2", "simple-mfd", "syscon";
+ reg = <0x1e789000 0x1000>;
+
+ #address-cells = <1>;
+ #size-cells = <1>;
+ ranges = <0x0 0x1e789000 0x1000>;
+
+ uart_routing: uart-routing@98 {
+ compatible = "aspeed,ast2600-uart-routing";
+ reg = <0x98 0x8>;
+ };
+ };
--
2.17.1
