Re: [PATCH v2 00/11] mfd: macsmc: add rtc, hwmon and hid subdevices

[Alexandre Belloni <alexandre.belloni@bootlin.com>]

Hello,

On 27/08/2025 21:22:34+1000, James Calligeros wrote:
> Hi all,
> 
> This series adds support for the remaining SMC subdevices. These are the
> RTC, hwmon, and HID devices. They are being submitted together as the RTC
> and hwmon drivers both require changes to the SMC DT schema.
> 

How do you expect this to be merged? From what I get, I could just take
1 and 3 as there doesn't seem to be any actual dependencies on any of
the other patches and the MFD change doesn't depend on the RTC changes.

> The RTC driver is responsible for getting and setting the system clock,
> and requires an NVMEM cell. This series replaces Sven's original RTC driver
> submission [1].
> 
> The hwmon function is an interesting one. While each Apple Silicon device
> exposes pretty similar sets of sensors, these all seem to be paired to
> different SMC keys in the firmware interface. This is true even when the
> sensors are on the SoC. For example, an M1 MacBook Pro will use different
> keys to access the LITTLE core temperature sensors to an M1 Mac mini. This
> necessitates describing which keys correspond to which sensors for each
> device individually, and populating the hwmon structs at runtime. We do
> this with a node in the device tree. This series includes only the keys
> for sensors which we know to be common to all devices. The SMC is also
> responsible for monitoring and controlling fan speeds on systems with fans,
> which we expose via the hwmon driver.
> 
> The SMC also handles the hardware power button and lid switch. Power
> button presses and lid opening/closing are emitted as HID events, so we
> add a HID subdevice to handle them.
> 
> Note that this series is based on a branch with three additional commits
> applied to add the parent SMC nodes to the relevant Devicetrees. This
> was done to silence build errors. The series applies cleanly to 6.17-rc1.
> 
> Regards,
> 
> James
> 
> [1] https://lore.kernel.org/asahi/CAEg-Je84XxLWH7vznQmPRfjf6GxWOu75ZetwN7AdseAwfMLLrQ@mail.gmail.com/T/#t
> 
> Signed-off-by: James Calligeros <jcalligeros99@gmail.com>
> ---
> Changes in v2:
> - Added Rob's R-b tag to RTC DT binding
> - Removed redundant nesting from hwmon DT binding
> - Dedpulicated property definitions in hwmon DT schema
> - Made label a required property for hwmon DT nodes
> - Clarified semantics in hwmon DT schema definitions
> - Split mfd tree changes into separate commits
> - Fixed numerous style errors in hwmon driver
> - Addressed Guenter's initial feedback on the hwmon driver
> - Modified hwmon driver to reflect DT schema changes
> - Added compatible property to hwmon node
> - Link to v1: https://lore.kernel.org/r/20250819-macsmc-subdevs-v1-0-57df6c3e5f19@gmail.com
> 
> ---
> Hector Martin (2):
>       rtc: Add new rtc-macsmc driver for Apple Silicon Macs
>       input: macsmc-hid: New driver to handle the Apple Mac SMC buttons/lid
> 
> James Calligeros (7):
>       dt-bindings: hwmon: Add Apple System Management Controller hwmon schema
>       mfd: macsmc: Wire up Apple SMC RTC subdevice
>       hwmon: Add Apple Silicon SMC hwmon driver
>       mfd: macsmc: Wire up Apple SMC hwmon subdevice
>       mfd: macsmc: Wire up Apple SMC HID subdevice
>       arm64: dts: apple: Add common hwmon sensors and fans
>       arm64: dts: apple: t8103, t600x, t8112: Add common hwmon nodes to devices
> 
> Sven Peter (2):
>       dt-bindings: rtc: Add Apple SMC RTC
>       arm64: dts: apple: t8103,t600x,t8112: Add SMC RTC node
> 
>  .../bindings/hwmon/apple,smc-hwmon.yaml  | 132 ++++
>  .../bindings/mfd/apple,smc.yaml          |  45 ++
>  .../bindings/rtc/apple,smc-rtc.yaml      |  35 +
>  MAINTAINERS                              |   5 +
>  .../boot/dts/apple/hwmon-common.dtsi     |  37 ++
>  .../boot/dts/apple/hwmon-fan-dual.dtsi   |  24 +
>  arch/arm64/boot/dts/apple/hwmon-fan.dtsi |  19 +
>  .../boot/dts/apple/hwmon-laptop.dtsi     |  35 +
>  .../boot/dts/apple/hwmon-mac-mini.dtsi   |  17 +
>  .../arm64/boot/dts/apple/t6001-j375c.dts |   2 +
>  .../arm64/boot/dts/apple/t6002-j375d.dts |   2 +
>  .../arm64/boot/dts/apple/t600x-die0.dtsi |   6 +
>  .../boot/dts/apple/t600x-j314-j316.dtsi  |   4 +
>  .../arm64/boot/dts/apple/t600x-j375.dtsi |   2 +
>  arch/arm64/boot/dts/apple/t8103-j274.dts |   2 +
>  arch/arm64/boot/dts/apple/t8103-j293.dts |   3 +
>  arch/arm64/boot/dts/apple/t8103-j313.dts |   2 +
>  arch/arm64/boot/dts/apple/t8103-j456.dts |   2 +
>  arch/arm64/boot/dts/apple/t8103-j457.dts |   2 +
>  .../arm64/boot/dts/apple/t8103-jxxx.dtsi |   2 +
>  arch/arm64/boot/dts/apple/t8103.dtsi     |   6 +
>  arch/arm64/boot/dts/apple/t8112-j413.dts |   2 +
>  arch/arm64/boot/dts/apple/t8112-j473.dts |   2 +
>  arch/arm64/boot/dts/apple/t8112-j493.dts |   3 +
>  .../arm64/boot/dts/apple/t8112-jxxx.dtsi |   2 +
>  arch/arm64/boot/dts/apple/t8112.dtsi     |   6 +
>  drivers/hwmon/Kconfig                    |  12 +
>  drivers/hwmon/Makefile                   |   1 +
>  drivers/hwmon/macsmc_hwmon.c             | 848 +++++++++++++++++++++++++
>  drivers/input/misc/Kconfig               |  11 +
>  drivers/input/misc/Makefile              |   1 +
>  drivers/input/misc/macsmc-hid.c          | 209 ++++++
>  drivers/mfd/macsmc.c                     |   3 +
>  drivers/rtc/Kconfig                      |  11 +
>  drivers/rtc/Makefile                     |   1 +
>  drivers/rtc/rtc-macsmc.c                 | 141 ++++
>  36 files changed, 1637 insertions(+)
> ---
> base-commit: 876d6a70b24869f96ebc8672caf86cb4bae72927
> change-id: 20250816-macsmc-subdevs-87032c017d0c
> 
> Best regards,
> -- 
> James Calligeros <jcalligeros99@gmail.com>
> 

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com