Kernel driver i2c-ali1535

Supported adapters:


This is the driver for the SMB Host controller on Acer Labs Inc. (ALI) M1535 South Bridge.

The M1535 is a South bridge for portable systems. It is very similar to the M15x3 South bridges also produced by Acer Labs Inc. Some of the registers within the part have moved and some have been redefined slightly. Additionally, the sequencing of the SMBus transactions has been modified to be more consistent with the sequencing recommended by the manufacturer and observed through testing. These changes are reflected in this driver and can be identified by comparing this driver to the i2c-ali15x3 driver. For an overview of these chips see

The SMB controller is part of the M7101 device, which is an ACPI-compliant Power Management Unit (PMU).

The whole M7101 device has to be enabled for the SMB to work. You can’t just enable the SMB alone. The SMB and the ACPI have separate I/O spaces. We make sure that the SMB is enabled. We leave the ACPI alone.


This driver controls the SMB Host only. This driver does not use interrupts.