ISMT(4D) Devices ISMT(4D)
ismt - Intel SMBus Message Transport driver
The ismt driver is an SMBus 3.0 controller with I2C support that is
present on various Intel Atom and Xeon-D platforms.
The ismt driver is part of the system's I2C framework and is accessible
through common tools such as i2cadm(8). The controller ssupports a
mixture of SMBus 2.0 and 3.0 features, but is still limited to a
32-byte block buffer and does not support the SMBus 32-bit and 64-bit
protocols directly in its SMBus operation. Unlike pchsmbus(4D), ismt
also has support for I2C based operations and can use up to a 240-byte
buffer for them. The ismt driver currently only has read-only
properties. While the controller supports a variable bus frequency,
these are supposed to only be set by fuses by the platform implementor.
x86
/kernel/drv/amd64/ismt Device driver (x86)
pchsmbus(4D), i2cadm(8)
illumos October 4, 2025 illumos
NAME
ismt - Intel SMBus Message Transport driver
DESCRIPTION
The ismt driver is an SMBus 3.0 controller with I2C support that is
present on various Intel Atom and Xeon-D platforms.
The ismt driver is part of the system's I2C framework and is accessible
through common tools such as i2cadm(8). The controller ssupports a
mixture of SMBus 2.0 and 3.0 features, but is still limited to a
32-byte block buffer and does not support the SMBus 32-bit and 64-bit
protocols directly in its SMBus operation. Unlike pchsmbus(4D), ismt
also has support for I2C based operations and can use up to a 240-byte
buffer for them. The ismt driver currently only has read-only
properties. While the controller supports a variable bus frequency,
these are supposed to only be set by fuses by the platform implementor.
ARCHITECTURE
x86
FILES
/kernel/drv/amd64/ismt Device driver (x86)
SEE ALSO
pchsmbus(4D), i2cadm(8)
illumos October 4, 2025 illumos