Currently, there is no way to obtain the fan's current speed on Microsoft Surface Series devices, this patch series adds a new module that provides read-only access to the fan's current speed through the hwmon system. This new module relies on the Surface System Aggregator Module which is the system responsible for communication with the EC on these devices. The first commit adds an entry into the SSAM registry for the fan's speed functionality (for the Surface Pro 9), the second commit adds the new module and documentation. Both patches can be applied independently of each other. Tested on a Microsoft Surface Pro 9. A full development log can be found on [1]. Fan control is always handled by the EC and cannot be influenced directly. It was identified during the development of this module that there are fan profiles between which can be switched. I'm currently developing improvements to the Surface platform profile module in [2] that will be submitted in the future. [1]: https://github.com/linux-surface/kernel/pull/144 [2]: https://github.com/linux-surface/kernel/pull/145 Ivor Wanders (2): hwmon: add fan speed monitoring driver for Surface devices platform/surface: aggregator_registry: add entry for fan speed Documentation/hwmon/index.rst | 1 + Documentation/hwmon/surface_fan.rst | 27 ++++ MAINTAINERS | 8 ++ drivers/hwmon/Kconfig | 13 ++ drivers/hwmon/Makefile | 1 + drivers/hwmon/surface_fan.c | 125 ++++++++++++++++++ .../surface/surface_aggregator_registry.c | 7 + 7 files changed, 182 insertions(+) create mode 100644 Documentation/hwmon/surface_fan.rst create mode 100644 drivers/hwmon/surface_fan.c -- 2.17.1
