On Thu, Sep 16, 2021 at 05:25:13PM +0800, Chia-Wei Wang wrote: > 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 54f080df5e2f..697331d840a0 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). This is about documenting the hardware, not an OS driver. sysfs files have their own documentation. > + > +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 > >
