0x00 - Microsoft: Type/Touch Cover

Technical information about Type/Touch Covers for Surface RT/2

I2C Specs

• HID over I2C

• Address: 0x00

• Bus speed: 400kHz

• HID_Descriptor: 0x0041

• ACPI Device: SNMU

• Power:

  • Bridge IC: PMIC.REG1: 1.8V

  • tCover Power: PMIC.REG3: 2.8V

GPIO

HID Interrupt: O5 Hotplug Interrupt: S0

Issue

The tCover I2C address is 0x00. This address is reserved for general call. Linux doesn't allow I2C Slaves to use this address therefore the I2C driver must be patched to allow 0x00 as valid Slave address.

Implementation

WIP: ARM: tegra: Support for Surface RT Type/Touch/Power-Cover; Display fix by jonasschwoebel · Pull Request #45 · grate-driver/linuxGitHub

i2c-hotplug-gpio is a grate driver and doesn't work in mainline.

VendorID / ProductID

Cover	Generation	VendorID / hex	ProductID / hex
Touch	1	045E	079A
Type	1	045E	079C
Touch	2	045E	07A7
Type	2	045E	07A9
Power	1	045E - tbc	07DA - tbc