xref: /linux/Documentation/devicetree/bindings/rtc/apple,smc-rtc.yaml (revision d324e9a91502184e0ac201293a6ec0fbe10458ed)
1*07049187SSven Peter# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2*07049187SSven Peter%YAML 1.2
3*07049187SSven Peter---
4*07049187SSven Peter$id: http://devicetree.org/schemas/rtc/apple,smc-rtc.yaml#
5*07049187SSven Peter$schema: http://devicetree.org/meta-schemas/core.yaml#
6*07049187SSven Peter
7*07049187SSven Petertitle: Apple SMC RTC
8*07049187SSven Peter
9*07049187SSven Peterdescription:
10*07049187SSven Peter  Apple Silicon Macs (M1, etc.) have an RTC that is part of the PMU IC,
11*07049187SSven Peter  but most of the PMU functionality is abstracted out by the SMC.
12*07049187SSven Peter  An additional RTC offset stored inside NVMEM is required to compute
13*07049187SSven Peter  the current date/time.
14*07049187SSven Peter
15*07049187SSven Petermaintainers:
16*07049187SSven Peter  - Sven Peter <sven@kernel.org>
17*07049187SSven Peter
18*07049187SSven Peterproperties:
19*07049187SSven Peter  compatible:
20*07049187SSven Peter    const: apple,smc-rtc
21*07049187SSven Peter
22*07049187SSven Peter  nvmem-cells:
23*07049187SSven Peter    items:
24*07049187SSven Peter      - description: 48bit RTC offset, specified in 32768 (2^15) Hz clock ticks
25*07049187SSven Peter
26*07049187SSven Peter  nvmem-cell-names:
27*07049187SSven Peter    items:
28*07049187SSven Peter      - const: rtc_offset
29*07049187SSven Peter
30*07049187SSven Peterrequired:
31*07049187SSven Peter  - compatible
32*07049187SSven Peter  - nvmem-cells
33*07049187SSven Peter  - nvmem-cell-names
34*07049187SSven Peter
35*07049187SSven PeteradditionalProperties: false
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