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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /Documentation/devicetree/bindings/mfd/aspeed-lpc.yaml
parentInitial commit. (diff)
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Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# # Copyright (c) 2021 Aspeed Tehchnology Inc.
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mfd/aspeed-lpc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Aspeed Low Pin Count (LPC) Bus Controller
+
+maintainers:
+ - Andrew Jeffery <andrew@aj.id.au>
+ - Chia-Wei Wang <chiawei_wang@aspeedtech.com>
+
+description:
+ The LPC bus is a means to bridge a host CPU to a number of low-bandwidth
+ peripheral devices, replacing the use of the ISA bus in the age of PCI[0]. The
+ primary use case of the Aspeed LPC controller is as a slave on the bus
+ (typically in a Baseboard Management Controller SoC), but under certain
+ conditions it can also take the role of bus master.
+
+ The LPC controller is represented as a multi-function device to account for the
+ mix of functionality, which includes, but is not limited to
+
+ * An IPMI Block Transfer[2] Controller
+
+ * An LPC Host Interface Controller manages functions exposed to the host such
+ as LPC firmware hub cycles, configuration of the LPC-to-AHB mapping, UART
+ management and bus snoop configuration.
+
+ * A set of SuperIO[3] scratch registers enabling implementation of e.g. custom
+ hardware management protocols for handover between the host and baseboard
+ management controller.
+
+ Additionally the state of the LPC controller influences the pinmux
+ configuration, therefore the host portion of the controller is exposed as a
+ syscon as a means to arbitrate access.
+
+properties:
+ compatible:
+ items:
+ - enum:
+ - aspeed,ast2400-lpc-v2
+ - aspeed,ast2500-lpc-v2
+ - aspeed,ast2600-lpc-v2
+ - const: simple-mfd
+ - const: syscon
+
+ reg:
+ maxItems: 1
+
+ "#address-cells":
+ const: 1
+
+ "#size-cells":
+ const: 1
+
+ ranges: true
+
+patternProperties:
+ "^lpc-ctrl@[0-9a-f]+$":
+ type: object
+ additionalProperties: false
+
+ description: |
+ The LPC Host Interface Controller manages functions exposed to the host such as
+ LPC firmware hub cycles, configuration of the LPC-to-AHB mapping, UART management
+ and bus snoop configuration.
+
+ properties:
+ compatible:
+ items:
+ - enum:
+ - aspeed,ast2400-lpc-ctrl
+ - aspeed,ast2500-lpc-ctrl
+ - aspeed,ast2600-lpc-ctrl
+
+ reg:
+ maxItems: 1
+
+ clocks:
+ maxItems: 1
+
+ memory-region:
+ maxItems: 1
+ description: handle to memory reservation for the LPC to AHB mapping region
+
+ flash:
+ $ref: /schemas/types.yaml#/definitions/phandle
+ description: The SPI flash controller containing the flash to be exposed over the LPC to AHB mapping
+
+ required:
+ - compatible
+ - clocks
+
+ "^reset-controller@[0-9a-f]+$":
+ type: object
+ additionalProperties: false
+
+ description:
+ The UARTs present in the ASPEED SoC can have their resets tied to the reset
+ state of the LPC bus. Some systems may chose to modify this configuration
+
+ properties:
+ compatible:
+ items:
+ - enum:
+ - aspeed,ast2400-lpc-reset
+ - aspeed,ast2500-lpc-reset
+ - aspeed,ast2600-lpc-reset
+
+ reg:
+ maxItems: 1
+
+ '#reset-cells':
+ const: 1
+
+ required:
+ - compatible
+ - '#reset-cells'
+
+ "^lpc-snoop@[0-9a-f]+$":
+ type: object
+ additionalProperties: false
+
+ description:
+ The LPC snoop interface allows the BMC to listen on and record the data
+ bytes written by the Host to the targeted LPC I/O pots.
+
+ properties:
+ compatible:
+ items:
+ - enum:
+ - aspeed,ast2400-lpc-snoop
+ - aspeed,ast2500-lpc-snoop
+ - aspeed,ast2600-lpc-snoop
+
+ reg:
+ maxItems: 1
+
+ interrupts:
+ maxItems: 1
+
+ snoop-ports:
+ $ref: /schemas/types.yaml#/definitions/uint32-array
+ description: The LPC I/O ports to snoop
+
+ required:
+ - compatible
+ - interrupts
+ - snoop-ports
+
+ "^uart-routing@[0-9a-f]+$":
+ $ref: /schemas/soc/aspeed/uart-routing.yaml#
+ description: The UART routing control under LPC register space
+
+required:
+ - compatible
+ - reg
+ - "#address-cells"
+ - "#size-cells"
+ - ranges
+
+additionalProperties:
+ type: object
+
+examples:
+ - |
+ #include <dt-bindings/interrupt-controller/arm-gic.h>
+ #include <dt-bindings/clock/ast2600-clock.h>
+
+ lpc: lpc@1e789000 {
+ compatible = "aspeed,ast2600-lpc-v2", "simple-mfd", "syscon";
+ reg = <0x1e789000 0x1000>;
+
+ #address-cells = <1>;
+ #size-cells = <1>;
+ ranges = <0x0 0x1e789000 0x1000>;
+
+ lpc_ctrl: lpc-ctrl@80 {
+ compatible = "aspeed,ast2600-lpc-ctrl";
+ reg = <0x80 0x80>;
+ clocks = <&syscon ASPEED_CLK_GATE_LCLK>;
+ memory-region = <&flash_memory>;
+ flash = <&spi>;
+ };
+
+ lpc_reset: reset-controller@98 {
+ compatible = "aspeed,ast2600-lpc-reset";
+ reg = <0x98 0x4>;
+ #reset-cells = <1>;
+ };
+
+ lpc_snoop: lpc-snoop@90 {
+ compatible = "aspeed,ast2600-lpc-snoop";
+ reg = <0x90 0x8>;
+ interrupts = <GIC_SPI 144 IRQ_TYPE_LEVEL_HIGH>;
+ snoop-ports = <0x80>;
+ };
+ };