diff options
| author | Sven Peter <sven@kernel.org> | 2025-11-12 21:16:47 +1000 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2025-12-08 22:41:59 +0100 |
| commit | 07049187e83072e187d7a9f3386286e59c83e8ee (patch) | |
| tree | aafd8d3e70cfe038db58e2701ea629dbcb25add9 /Documentation | |
| parent | 40d8123ff7492d014d9396a458b344d59cec3c6b (diff) | |
dt-bindings: rtc: Add Apple SMC RTC
Apple Silicon Macs (M1, etc.) have an RTC that is part of the PMU IC,
but most of the PMU functionality is abstracted out by the SMC.
An additional RTC offset stored inside NVMEM is required to compute
the current date/time.
Reviewed-by: Mark Kettenis <kettenis@openbsd.org>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Sven Peter <sven@kernel.org>
Signed-off-by: James Calligeros <jcalligeros99@gmail.com>
Reviewd-by: Mark Kettenis <kettenis@openbsd.org>
Link: https://patch.msgid.link/20251112-macsmc-subdevs-v5-1-728e4b91fe81@gmail.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/devicetree/bindings/mfd/apple,smc.yaml | 9 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/rtc/apple,smc-rtc.yaml | 35 |
2 files changed, 44 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/mfd/apple,smc.yaml b/Documentation/devicetree/bindings/mfd/apple,smc.yaml index 5429538f7e2e..0410e712c900 100644 --- a/Documentation/devicetree/bindings/mfd/apple,smc.yaml +++ b/Documentation/devicetree/bindings/mfd/apple,smc.yaml @@ -46,6 +46,9 @@ properties: reboot: $ref: /schemas/power/reset/apple,smc-reboot.yaml + rtc: + $ref: /schemas/rtc/apple,smc-rtc.yaml + additionalProperties: false required: @@ -80,5 +83,11 @@ examples: nvmem-cell-names = "shutdown_flag", "boot_stage", "boot_error_count", "panic_count"; }; + + rtc { + compatible = "apple,smc-rtc"; + nvmem-cells = <&rtc_offset>; + nvmem-cell-names = "rtc_offset"; + }; }; }; diff --git a/Documentation/devicetree/bindings/rtc/apple,smc-rtc.yaml b/Documentation/devicetree/bindings/rtc/apple,smc-rtc.yaml new file mode 100644 index 000000000000..607b610665a2 --- /dev/null +++ b/Documentation/devicetree/bindings/rtc/apple,smc-rtc.yaml @@ -0,0 +1,35 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/rtc/apple,smc-rtc.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Apple SMC RTC + +description: + Apple Silicon Macs (M1, etc.) have an RTC that is part of the PMU IC, + but most of the PMU functionality is abstracted out by the SMC. + An additional RTC offset stored inside NVMEM is required to compute + the current date/time. + +maintainers: + - Sven Peter <sven@kernel.org> + +properties: + compatible: + const: apple,smc-rtc + + nvmem-cells: + items: + - description: 48bit RTC offset, specified in 32768 (2^15) Hz clock ticks + + nvmem-cell-names: + items: + - const: rtc_offset + +required: + - compatible + - nvmem-cells + - nvmem-cell-names + +additionalProperties: false |