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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /Documentation/devicetree/bindings/clock/arm,syscon-icst.yaml | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'Documentation/devicetree/bindings/clock/arm,syscon-icst.yaml')
-rw-r--r-- | Documentation/devicetree/bindings/clock/arm,syscon-icst.yaml | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/clock/arm,syscon-icst.yaml b/Documentation/devicetree/bindings/clock/arm,syscon-icst.yaml new file mode 100644 index 0000000000..b5533f8130 --- /dev/null +++ b/Documentation/devicetree/bindings/clock/arm,syscon-icst.yaml @@ -0,0 +1,110 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/clock/arm,syscon-icst.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: ARM System Controller ICST Clocks + +maintainers: + - Linus Walleij <linusw@kernel.org> + +description: | + The ICS525 and ICS307 oscillators are produced by Integrated + Devices Technology (IDT). ARM integrated these oscillators deeply into their + reference designs by adding special control registers that manage such + oscillators to their system controllers. + + The various ARM system controllers contain logic to serialize and initialize + an ICST clock request after a write to the 32 bit register at an offset + into the system controller. Furthermore, to even be able to alter one of + these frequencies, the system controller must first be unlocked by + writing a special token to another offset in the system controller. + + Some ARM hardware contain special versions of the serial interface that only + connects the low 8 bits of the VDW (missing one bit), hard-wires RDW to + different values and sometimes also hard-wires the output divider. They + therefore have special compatible strings as per this table (the OD value is + the value on the pins, not the resulting output divider). + + In the core modules and logic tiles, the ICST is a configurable clock fed + from a 24 MHz clock on the motherboard (usually the main crystal) used for + generating e.g. video clocks. It is located on the core module and there is + only one of these. This clock node must be a subnode of the core module. + + Hardware variant RDW OD VDW + + Integrator/AP 22 1 Bit 8 0, rest variable + integratorap-cm + + Integrator/AP 46 3 Bit 8 0, rest variable + integratorap-sys + + Integrator/AP 22 or 1 17 or (33 or 25 MHz) + integratorap-pci 14 1 14 + + Integrator/CP 22 variable Bit 8 0, rest variable + integratorcp-cm-core + + Integrator/CP 22 variable Bit 8 0, rest variable + integratorcp-cm-mem + + The ICST oscillator must be provided inside a system controller node. + +properties: + "#clock-cells": + const: 0 + + compatible: + enum: + - arm,syscon-icst525 + - arm,syscon-icst307 + - arm,syscon-icst525-integratorap-cm + - arm,syscon-icst525-integratorap-sys + - arm,syscon-icst525-integratorap-pci + - arm,syscon-icst525-integratorcp-cm-core + - arm,syscon-icst525-integratorcp-cm-mem + - arm,integrator-cm-auxosc + - arm,versatile-cm-auxosc + - arm,impd1-vco1 + - arm,impd1-vco2 + + reg: + maxItems: 1 + description: The VCO register + + clocks: + description: Parent clock for the ICST VCO + maxItems: 1 + + clock-output-names: + maxItems: 1 + + lock-offset: + $ref: /schemas/types.yaml#/definitions/uint32 + description: Offset to the unlocking register for the oscillator + + vco-offset: + $ref: /schemas/types.yaml#/definitions/uint32 + description: Offset to the VCO register for the oscillator + deprecated: true + +required: + - "#clock-cells" + - compatible + - clocks + +additionalProperties: false + +examples: + - | + vco1: clock { + compatible = "arm,impd1-vco1"; + #clock-cells = <0>; + lock-offset = <0x08>; + vco-offset = <0x00>; + clocks = <&sysclk>; + clock-output-names = "IM-PD1-VCO1"; + }; + +... |