Apple Sudden Motion Sensor for PowerPC PowerBooks and iBooks
The accelerometer Apple built into its PowerPC PowerBook and iBook laptops in the mid-2000s, used to detect sudden drops so the hard disk could park its heads before impact. Both the original variant and an I2C version found in early 2005 models are supported, and the hardware disappeared when Apple ended the PowerBook and iBook lines in May 2006.
recommendation
Worth keeping but documenting as legacy hardware: the affected laptops have not been sold since 2006 and no replacement driver exists, but the code is still receiving small maintenance fixes from PowerPC kernel developers as recently as 2023 and 2024, and a niche population of surviving PowerBooks and iBooks still relies on it. There is no upstream effort to remove it, so the sensible path is to leave it in place while flagging that it serves only obsolete Apple PowerPC laptops.
repository signals
sources
- lore.kernel.org
ams-core.c still received upstream maintenance in 2024 ('macintosh/ams: Fix unused variable warning').
- lore.kernel.org
ams-core.c also saw upstream cleanup in 2023 ('macintosh/ams: mark ams_init() static'), indicating the driver is not abandoned.
- cateee.net
LKDDb describes CONFIG_SENSORS_AMS as the Apple Motion Sensor driver for PowerBooks and shows it remains present in current kernel series.
- cateee.net
LKDDb states the I2C variant is found in early 2005 PowerBooks and iBooks, tying the hardware to legacy PowerPC Apple laptops.
- en.wikipedia.org
PowerBook was discontinued on May 16, 2006.
- en.wikipedia.org
iBook was discontinued on May 16, 2006.
codex reasoning notes (technical)
Read local source with exec_command: the driver is explicitly 'Apple Motion Sensor', probes PowerPC Mac Open Firmware nodes ('accelerometer'/'sms'), and is constrained to legacy Apple laptop hardware. Lore evidence came from lore_file_timeline on drivers/macintosh/ams/ams-core.c; it shows small maintenance fixes in 2021/2023/2024 and no evident removal series, so 'remove' is not justified. Deployment is therefore legacy-but-nonzero: surviving PowerBook/iBook systems still exist, but new hardware stopped in 2006 and nothing suggests new 2025 shipments. Web URLs were obtained via web search_query; LKDDb supports hardware scope/current kernel presence, while Wikipedia pages support the 2006 end-of-sale date. No natural replacement driver is visible; the use case disappeared with the platform, so the best fit is keep the driver but annotate it as legacy/obsolete hardware.