Baikal-T1 CPU or DMAC MMIO requests are handled by the AMBA 3 AXI Interconnect which routes them to the AXI-APB bridge, which in turn serializes accesses and routes them to the corresponding APB slave device. This binding describes the AXI-APB bridge considered as the APB-bus. It is supposed to be compatible with "be,bt1-apb" and "simple-bus" drivers, should be equipped with EHB MMIO region and a region with no slave device mapped, interrupts line number, APB reference clock and domain reset line. Signed-off-by: Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx> Cc: Alexey Malahov <Alexey.Malahov@xxxxxxxxxxxxxxxxxxxx> Cc: Paul Burton <paulburton@xxxxxxxxxx> Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx> Cc: Tony Lindgren <tony@xxxxxxxxxxx> Cc: Tero Kristo <t-kristo@xxxxxx> Cc: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx> Cc: Jeffrey Hugo <jhugo@xxxxxxxxxxxxxx> Cc: Linus Walleij <linus.walleij@xxxxxxxxxx> Cc: Olof Johansson <olof@xxxxxxxxx> Cc: linux-mips@xxxxxxxxxxxxxxx Cc: soc@xxxxxxxxxx --- Rob, I had to remove your Reviewed-by tag, since new changes had been introduced. Changelog v2: - Move driver to the bus subsystem. - Don't use a multi-arg clock phandle reference in the examples dt-bindings property. Thus redundant include statement can be removed. - Use dual GPL/BSD license. - Use single lined copyright header. - Lowercase the unit-address. - Convert a dedicated EHB block binding to the Baikal-T1 APB-bus one. - Add APB reference clock and reset support. - Replace "additionalProperties: false" property with "unevaluatedProperties: false". - Add reg-names property. --- .../bindings/bus/baikal,bt1-apb.yaml | 90 +++++++++++++++++++ 1 file changed, 90 insertions(+) create mode 100644 Documentation/devicetree/bindings/bus/baikal,bt1-apb.yaml diff --git a/Documentation/devicetree/bindings/bus/baikal,bt1-apb.yaml b/Documentation/devicetree/bindings/bus/baikal,bt1-apb.yaml new file mode 100644 index 000000000000..d6a3b71ea835 --- /dev/null +++ b/Documentation/devicetree/bindings/bus/baikal,bt1-apb.yaml @@ -0,0 +1,90 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +# Copyright (C) 2020 BAIKAL ELECTRONICS, JSC +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/bus/baikal,bt1-apb.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Baikal-T1 APB-bus + +maintainers: + - Serge Semin <fancer.lancer@xxxxxxxxx> + +description: | + Baikal-T1 CPU or DMAC MMIO requests are handled by the AMBA 3 AXI Interconnect + which routes them to the AXI-APB bridge. This interface is a single master + multiple slaves bus in turn serializing IO accesses and routing them to the + addressed APB slave devices. In case of any APB protocol collisions, slave + device not responding on timeout an IRQ is raised with an erroneous address + reported to the APB terminator (APB Errors Handler Block). + +allOf: + - $ref: /schemas/simple-bus.yaml# + +properties: + compatible: + contains: + const: baikal,bt1-apb + + reg: + items: + - description: APB EHB MMIO registers + - description: APB MMIO region with no any device mapped + + reg-names: + items: + - const: ehb + - const: nodev + + interrupts: + maxItems: 1 + + clocks: + items: + - description: APB reference clock + + clock-names: + items: + - const: pclk + + resets: + items: + - description: APB domain reset line + + reset-names: + items: + - const: prst + +unevaluatedProperties: false + +required: + - compatible + - reg + - reg-names + - interrupts + - clocks + - clock-names + +examples: + - | + #include <dt-bindings/interrupt-controller/mips-gic.h> + + bus@1f059000 { + compatible = "baikal,bt1-apb", "simple-bus"; + reg = <0 0x1f059000 0 0x1000>, + <0 0x1d000000 0 0x2040000>; + reg-names = "ehb", "nodev"; + #address-cells = <1>; + #size-cells = <1>; + + ranges; + + interrupts = <GIC_SHARED 16 IRQ_TYPE_LEVEL_HIGH>; + + clocks = <&ccu_sys 1>; + clock-names = "pclk"; + + resets = <&ccu_sys 1>; + reset-names = "prst"; + }; +... -- 2.25.1
