Documentation/hwmon/occ

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

Supported chips:
  * POWER8
  * POWER9

Author: Eddie James <eajames@us.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. Please see the
device-tree bindings documentation for that driver for details on probing
an OCC device (Documentation/devicetree/bindings/fsi/ibm,p9-occ.txt).

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

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

temp[1-n]_label		OCC sensor id.
temp[1-n]_input		Measured temperature in millidegrees C.
[with temperature sensor version 2+]
    temp[1-n]_fru_type		Given FRU (Field Replaceable Unit) type.
    temp[1-n]_fault		Temperature sensor fault.

freq[1-n]_label		OCC sensor id.
freq[1-n]_input		Measured frequency.

power[1-n]_label	OCC sensor id.
power[1-n]_input	Measured power in microwatts.
power[1-n]_update_tag	Number of 250us samples represented in accumulator.
power[1-n]_accumulator	Accumulation of 250us power readings.
[with power sensor version 2+]
    power[1-n]_function_id	Identifies what the power reading is for.
    power[1-n]_apss_channel	Indicates APSS channel.

[power version 0xa0 only]
power1_id			OCC sensor id.
power[1-n]_label		Sensor type, "system", "proc", "vdd", or "vdn".
power[1-n]_input		Most recent power reading in microwatts.
power[1-n]_update_tag		Number of samples in the accumulator.
power[1-n]_accumulator		Accumulation of power readings.
[with sensor type "system" and "proc" only]
    power[1-n]_update_time	Time in us that the power value is read.

caps1_current		Current OCC power cap in watts.
caps1_reading		Current system output power in watts.
caps1_norm		Power cap without redundant power.
caps1_max		Maximum power cap.
[caps version 1 and 2 only]
    caps1_min		Minimum power cap.
[caps version 3+]
    caps1_min_hard		Hard minimum cap that can be set and held.
    caps1_min_soft		Soft minimum cap below hard, not guaranteed.
caps1_user		The powercap specified by the user. Will be 0 if no
			user powercap exists. This attribute is read-write.
[caps version 1+]
    caps1_user_source	Indicates how the user power limit was set.

extn[1-n]_label		ASCII id or sensor id.
extn[1-n]_flags		Indicates type of label attribute.
extn[1-n]_input		Data.