Documentation/hwmon/occ.rst

Source file repositories/reference/linux-study-clean/Documentation/hwmon/occ.rst

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Linux kernel
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Documentation/hwmon/occ.rst
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.rst
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Support Tooling And Documentation
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Documentation
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Support Tooling And Documentation: documentation
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Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

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Kernel driver occ-hwmon
=======================

Supported chips:

  * POWER8
  * POWER9

Author: Eddie James <eajames@linux.ibm.com>

Description
-----------

This driver supports hardware monitoring for the On-Chip Controller (OCC)
embedded on POWER processors. The OCC is a device that collects and aggregates
sensor data from the processor and the system. The OCC can provide the raw
sensor data as well as perform thermal and power management on the system.

The P8 version of this driver is a client driver of I2C. It may be probed
manually if an "ibm,p8-occ-hwmon" compatible device is found under the
appropriate I2C bus node in the device-tree.

The P9 version of this driver is a client driver of the FSI-based OCC driver.
It will be probed automatically by the FSI-based OCC driver.

Sysfs entries
-------------

The following attributes are supported. All attributes are read-only unless
specified.

The OCC sensor ID is an integer that represents the unique identifier of the
sensor with respect to the OCC. For example, a temperature sensor for the third
DIMM slot in the system may have a sensor ID of 7. This mapping is unavailable
to the device driver, which must therefore export the sensor ID as-is.

Some entries are only present with certain OCC sensor versions or only on
certain OCCs in the system. The version number is not exported to the user
but can be inferred.

temp[1-n]_label
	OCC sensor ID.

[with temperature sensor version 1]

    temp[1-n]_input
			Measured temperature of the component in millidegrees
			Celsius.

[with temperature sensor version >= 2]

    temp[1-n]_type
				The FRU (Field Replaceable Unit) type
				(represented by an integer) for the component
				that this sensor measures.
    temp[1-n]_fault
				Temperature sensor fault boolean; 1 to indicate
				that a fault is present or 0 to indicate that
				no fault is present.

    [with type == 3 (FRU type is VRM)]

	temp[1-n]_alarm
				VRM temperature alarm boolean; 1 to indicate
				alarm, 0 to indicate no alarm

    [else]

	temp[1-n]_input
				Measured temperature of the component in

Annotation

Implementation Notes