[PATCH v6 0/2] Add Apple Silicon SMC power driver

[Sebastian Reichel]

Hi,

On Mon, Jan 26, 2026 at 10:16:55AM +1100, Michael Reeves via B4 Relay wrote:
> This series adds a power supply driver for the Apple SMC found on
> Apple Silicon devices. This allows the kernel to report AC status,
> battery charging status, and power metrics, and modify the charging
> behaviour.
> 
> The first patch adds the driver itself, and the second patch wires it
> up to the MFD core.
> 
> The driver is based on an original out-of-tree implementation by
> Hector Martin. It has been refactored by myself for upstream inclusion, 
> including support for newer SMC firmwares, devices without batteries,
> dynamic property detection and improved state management, among other
> things.
> 
> This series is based ontop of the current linux-next at time of writing,
> the exact commit hash is listed below.
> 
> Tested on: Apple M3 (MacBook Air, J613)
> 
> Signed-off-by: Michael Reeves <michael.reeves077 at gmail.com>
> ---
> Changes in v6:
> - Add FS header include for emergency_sync()
> - Link to v5: https://lore.kernel.org/r/20260126-b4-macsmc-power-v5-0-302462673b18@gmail.com

This fails to build as module, since emergency_sync() is not exported:

ERROR: modpost: "emergency_sync" [drivers/power/supply/macsmc-power.ko] undefined!
make[2]: *** [scripts/Makefile.modpost:147: Module.symvers] Error 1

Greetings,

-- Sebastian

> Changes in v5:
> - Readd cover subject that mistakenly got dropped, apologies.
> - Link to v4: https://lore.kernel.org/r/20260126-b4-macsmc-power-v4-0-aa2a682ca650@gmail.com
> 
> Changes in v4:
> - Restore Hector Martin as primary author for the series.
> - Restore downstream Co-developed-by and Signed-off-by tags.
> - Add Reviewed-by: Sven Peter <sven at kernel.org>.
> - Simplify MFD patch authorship and remove redundant tags.
> - Fix probe return value being overwritten by devm_work_autocancel.
> - Return -ENODEV in probe if neither battery nor AC adapter are found.
> - Add bounds check for nprops against MACSMC_MAX_BATT_PROPS.
> - Refactor macsmc_battery_set_charge_behaviour to remove unnecessary resets.
> - Improve critical_work shutdown flags and remove return.
> - Add comments explaining SMC key firmware history and flag meanings.
> - Clarify event ID descriptions and restore BSFC flag comments.
> - Remove redundant dev_dbg logs for missing battery or AC.
> - Link to v3: https://lore.kernel.org/r/20260115-b4-macsmc-power-v3-0-c236e09874be@gmail.com
> 
> Changes in v3:
> - Rebase on top of latest linux-next
> - Drop charge control threshold properties.
> - Switch to devm_work_autocancel() for critical work.
> - Add platform ID table and remove MODULE_ALIAS.
> - Simplify property array management in struct macsmc_power.
> - Improve probe error handling and device pointer usage.
> - Minor style and indentation fixes.
> - Link to v2: https://lore.kernel.org/r/20260109-b4-macsmc-power-v2-0-93818f1e7d62@gmail.com
> 
> Changes in v2:
> - Added Reviewed-by: Neal Gompa <neal at gompa.dev> to all patches.
> - Fixed Makefile alignment by using tabs for the macsmc-power entry.
> - Upgraded physical battery exhaustion log level to EMERG.
> - Downgraded software-triggered orderly poweroff log level to CRIT.
> - Added check for CHIS key to skip AC registration on desktop models.
> - Link to v1: https://lore.kernel.org/r/20260105-b4-macsmc-power-v1-0-62954c42a555@gmail.com
> 
> ---
> Hector Martin (2):
>       power: supply: Add macsmc-power driver for Apple Silicon
>       mfd: macsmc: Wire up Apple SMC power driver
> 
>  MAINTAINERS                         |   1 +
>  drivers/mfd/macsmc.c                |   1 +
>  drivers/power/supply/Kconfig        |  11 +
>  drivers/power/supply/Makefile       |   1 +
>  drivers/power/supply/macsmc-power.c | 852 ++++++++++++++++++++++++++++++++++++
>  5 files changed, 866 insertions(+)
> ---
> base-commit: ca3a02fda4da8e2c1cb6baee5d72352e9e2cfaea
> change-id: 20260125-b4-macsmc-power-bb30389e05f1
> 
> Best regards,
> -- 
> Michael Reeves <michael.reeves077 at gmail.com>
> 
> 
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