This adds device tree bindings for the IXP4xx expansion bus controller. Cc: Marc Zyngier <maz@xxxxxxxxxx> Cc: devicetree@xxxxxxxxxxxxxxx Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx> --- ChangeLog v2->v3: - Add syscon as second compatible. The device contains a set of misc registers apart from the chip select control. - Add required "native-endianness" flag on the node and describe why. - Change bool flags into enum [0, 1]. The reason is that we need to be able to indicate clearly that we want an option to be zeroed as the OS will read/modify/write the config from the bootloader/power-on-defaults which sometimes means disabling things that would only be possibel to turn on with flags. ChangeLog v1->v2: - Drop unevaluatedProperties: false from the node match. additionalProperties: true will be the default. --- ...intel,ixp4xx-expansion-bus-controller.yaml | 168 ++++++++++++++++++ 1 file changed, 168 insertions(+) create mode 100644 Documentation/devicetree/bindings/bus/intel,ixp4xx-expansion-bus-controller.yaml diff --git a/Documentation/devicetree/bindings/bus/intel,ixp4xx-expansion-bus-controller.yaml b/Documentation/devicetree/bindings/bus/intel,ixp4xx-expansion-bus-controller.yaml new file mode 100644 index 000000000000..bd569670bca9 --- /dev/null +++ b/Documentation/devicetree/bindings/bus/intel,ixp4xx-expansion-bus-controller.yaml @@ -0,0 +1,168 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/bus/intel,ixp4xx-expansion-bus-controller.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Intel IXP4xx Expansion Bus Controller + +description: | + The IXP4xx expansion bus controller handles access to devices on the + memory-mapped expansion bus on the Intel IXP4xx family of system on chips, + including IXP42x, IXP43x, IXP45x and IXP46x. + +maintainers: + - Linus Walleij <linus.walleij@xxxxxxxxxx> + +properties: + $nodename: + pattern: '^bus@[0-9a-f]+$' + + compatible: + items: + - enum: + - intel,ixp42x-expansion-bus-controller + - intel,ixp43x-expansion-bus-controller + - intel,ixp45x-expansion-bus-controller + - intel,ixp46x-expansion-bus-controller + - const: syscon + + reg: + description: Control registers for the expansion bus, these are not + inside the memory range handled by the expansion bus. + maxItems: 1 + + native-endian: + $ref: /schemas/types.yaml#/definitions/flag + description: The IXP4xx has a peculiar MMIO access scheme, as it changes + the access pattern for words (swizzling) on the bus depending on whether + the SoC is running in big-endian or little-endian mode. Thus the + registers must always be accessed using native endianness. + + "#address-cells": + description: | + The first cell is the chip select numer. + The second cell is the address offset within the bank. + const: 2 + + "#size-cells": + const: 1 + + ranges: true + dma-ranges: true + +patternProperties: + "^.*@[0-7],[0-9a-f]+$": + description: Devices attached to chip selects are represented as + subnodes. + type: object + + properties: + intel,ixp4xx-eb-t1: + description: Address timing, extend address phase with n cycles. + $ref: /schemas/types.yaml#/definitions/uint32 + maximum: 3 + + intel,ixp4xx-eb-t2: + description: Setup chip select timing, extend setup phase with n cycles. + $ref: /schemas/types.yaml#/definitions/uint32 + maximum: 3 + + intel,ixp4xx-eb-t3: + description: Strobe timing, extend strobe phase with n cycles. + $ref: /schemas/types.yaml#/definitions/uint32 + maximum: 15 + + intel,ixp4xx-eb-t4: + description: Hold timing, extend hold phase with n cycles. + $ref: /schemas/types.yaml#/definitions/uint32 + maximum: 3 + + intel,ixp4xx-eb-t5: + description: Recovery timing, extend recovery phase with n cycles. + $ref: /schemas/types.yaml#/definitions/uint32 + maximum: 15 + + intel,ixp4xx-eb-cycle-type: + description: The type of cycles to use on the expansion bus for this + chip select. 0 = Intel cycles, 1 = Motorola cycles, 2 = HPI cycles. + $ref: /schemas/types.yaml#/definitions/uint32 + enum: [0, 1, 2] + + intel,ixp4xx-eb-byte-access-on-halfword: + description: Allow byte read access on half word devices. + $ref: /schemas/types.yaml#/definitions/uint32 + enum: [0, 1] + + intel,ixp4xx-eb-hpi-hrdy-pol-high: + description: Set HPI HRDY polarity to active high when using HPI. + $ref: /schemas/types.yaml#/definitions/uint32 + enum: [0, 1] + + intel,ixp4xx-eb-mux-address-and-data: + description: Multiplex address and data on the data bus. + $ref: /schemas/types.yaml#/definitions/uint32 + enum: [0, 1] + + intel,ixp4xx-eb-ahb-split-transfers: + description: Enable AHB split transfers. + $ref: /schemas/types.yaml#/definitions/uint32 + enum: [0, 1] + + intel,ixp4xx-eb-write-enable: + description: Enable write cycles. + $ref: /schemas/types.yaml#/definitions/uint32 + enum: [0, 1] + + intel,ixp4xx-eb-byte-access: + description: Expansion bus uses only 8 bits. The default is to use + 16 bits. + $ref: /schemas/types.yaml#/definitions/uint32 + enum: [0, 1] + +required: + - compatible + - reg + - native-endian + - "#address-cells" + - "#size-cells" + - ranges + - dma-ranges + +additionalProperties: false + +examples: + - | + #include <dt-bindings/interrupt-controller/irq.h> + bus@50000000 { + compatible = "intel,ixp42x-expansion-bus-controller", "syscon"; + reg = <0xc4000000 0x28>; + native-endian; + #address-cells = <2>; + #size-cells = <1>; + ranges = <0 0x0 0x50000000 0x01000000>, + <1 0x0 0x51000000 0x01000000>; + dma-ranges = <0 0x0 0x50000000 0x01000000>, + <1 0x0 0x51000000 0x01000000>; + flash@0,0 { + compatible = "intel,ixp4xx-flash", "cfi-flash"; + bank-width = <2>; + reg = <0 0x00000000 0x1000000>; + intel,ixp4xx-eb-t3 = <3>; + intel,ixp4xx-eb-cycle-type = <0>; + intel,ixp4xx-eb-byte-access-on-halfword = <1>; + intel,ixp4xx-eb-write-enable = <1>; + intel,ixp4xx-eb-byte-access = <0>; + }; + serial@1,0 { + compatible = "exar,xr16l2551", "ns8250"; + reg = <1 0x00000000 0x10>; + interrupt-parent = <&gpio0>; + interrupts = <4 IRQ_TYPE_LEVEL_LOW>; + clock-frequency = <1843200>; + intel,ixp4xx-eb-t3 = <3>; + intel,ixp4xx-eb-cycle-type = <1>; + intel,ixp4xx-eb-write-enable = <1>; + intel,ixp4xx-eb-byte-access = <1>; + }; + }; -- 2.31.1
