For facial unlocking, Linux 6.2will incorporate a "human sensor" driver in ChromeOS

CTOnews.com, December 13 (Xinhua)-- Linux 6.2 will soon incorporate the "Human body Sensor" (HPS) driver in ChromeOS, which is used to unlock the face. The Linux 6.2 kernel mainline will integrate the cros_hps_i2c driver to support "human sensor" on the Chromebook.

CTOnews.com learned that the cros_hps_i2c kernel driver itself does not report to you whether a human is detected, but that user space (user-space) docks with the sensor through an exposed character device. Google's patch set explains this new driver:

This patch introduces a driver for ChromeOS's human sensor, also known as HPS. The driver supports a sensor connected to the I2C bus and is identified as "GOOG0020" in the ACPI table.

After loading, the driver outputs the sensor to the user space through a character device. This device only supports power management, that is, communication with the sensor must be done through regular I2C transmission in user space.

Power management is achieved by enabling the respective power GPIO, while at least one user-space process holds an open fd on the character device. By default, if there is no active client, the device is powered off.

For those who have privacy concerns about Google's long-popular Chromebooks human presence sensors, as a pleasant attribute, at least the hardware firmware is open source. HPS device firmware, I2C protocol and other technical documents can be found on GoogleSource.com.