1Kernel driver occ-hwmon
  2=======================
  3
  4Supported chips:
  5
  6  * POWER8
  7  * POWER9
  8
  9Author: Eddie James <eajames@linux.ibm.com>
 10
 11Description
 12-----------
 13
 14This driver supports hardware monitoring for the On-Chip Controller (OCC)
 15embedded on POWER processors. The OCC is a device that collects and aggregates
 16sensor data from the processor and the system. The OCC can provide the raw
 17sensor data as well as perform thermal and power management on the system.
 18
 19The P8 version of this driver is a client driver of I2C. It may be probed
 20manually if an "ibm,p8-occ-hwmon" compatible device is found under the
 21appropriate I2C bus node in the device-tree.
 22
 23The P9 version of this driver is a client driver of the FSI-based OCC driver.
 24It will be probed automatically by the FSI-based OCC driver.
 25
 26Sysfs entries
 27-------------
 28
 29The following attributes are supported. All attributes are read-only unless
 30specified.
 31
 32The OCC sensor ID is an integer that represents the unique identifier of the
 33sensor with respect to the OCC. For example, a temperature sensor for the third
 34DIMM slot in the system may have a sensor ID of 7. This mapping is unavailable
 35to the device driver, which must therefore export the sensor ID as-is.
 36
 37Some entries are only present with certain OCC sensor versions or only on
 38certain OCCs in the system. The version number is not exported to the user
 39but can be inferred.
 40
 41temp[1-n]_label
 42	OCC sensor ID.
 43
 44[with temperature sensor version 1]
 45
 46    temp[1-n]_input
 47			Measured temperature of the component in millidegrees
 48			Celsius.
 49
 50[with temperature sensor version >= 2]
 51
 52    temp[1-n]_type
 53				The FRU (Field Replaceable Unit) type
 54				(represented by an integer) for the component
 55				that this sensor measures.
 56    temp[1-n]_fault
 57				Temperature sensor fault boolean; 1 to indicate
 58				that a fault is present or 0 to indicate that
 59				no fault is present.
 60
 61    [with type == 3 (FRU type is VRM)]
 62
 63	temp[1-n]_alarm
 64				VRM temperature alarm boolean; 1 to indicate
 65				alarm, 0 to indicate no alarm
 66
 67    [else]
 68
 69	temp[1-n]_input
 70				Measured temperature of the component in
 71				millidegrees Celsius.
 72
 73freq[1-n]_label
 74			OCC sensor ID.
 75freq[1-n]_input
 76			Measured frequency of the component in MHz.
 77power[1-n]_input
 78			Latest measured power reading of the component in
 79			microwatts.
 80power[1-n]_average
 81			Average power of the component in microwatts.
 82power[1-n]_average_interval
 83				The amount of time over which the power average
 84				was taken in microseconds.
 85
 86[with power sensor version < 2]
 87
 88    power[1-n]_label
 89			OCC sensor ID.
 90
 91[with power sensor version >= 2]
 92
 93    power[1-n]_label
 94			OCC sensor ID + function ID + channel in the form
 95			of a string, delimited by underscores, i.e. "0_15_1".
 96			Both the function ID and channel are integers that
 97			further identify the power sensor.
 98
 99[with power sensor version 0xa0]
100
101    power[1-n]_label
102			OCC sensor ID + sensor type in the form of a string,
103			delimited by an underscore, i.e. "0_system". Sensor
104			type will be one of "system", "proc", "vdd" or "vdn".
105			For this sensor version, OCC sensor ID will be the same
106			for all power sensors.
107
108[present only on "master" OCC; represents the whole system power; only one of
109this type of power sensor will be present]
110
111    power[1-n]_label
112				"system"
113    power[1-n]_input
114				Latest system output power in microwatts.
115    power[1-n]_cap
116				Current system power cap in microwatts.
117    power[1-n]_cap_not_redundant
118				System power cap in microwatts when
119				there is not redundant power.
120    power[1-n]_cap_max
121				Maximum power cap that the OCC can enforce in
122				microwatts.
123    power[1-n]_cap_min		Minimum power cap that the OCC can enforce in
124				microwatts.
125    power[1-n]_cap_user		The power cap set by the user, in microwatts.
126				This attribute will return 0 if no user power
127				cap has been set. This attribute is read-write,
128				but writing any precision below watts will be
129				ignored, i.e. requesting a power cap of
130				500900000 microwatts will result in a power cap
131				request of 500 watts.
132
133    [with caps sensor version > 1]
134
135	power[1-n]_cap_user_source
136					Indicates how the user power cap was
137					set. This is an integer that maps to
138					system or firmware components that can
139					set the user power cap.
140
141The following "extn" sensors are exported as a way for the OCC to provide data
142that doesn't fit anywhere else. The meaning of these sensors is entirely
143dependent on their data, and cannot be statically defined.
144
145extn[1-n]_label
146			ASCII ID or OCC sensor ID.
147extn[1-n]_flags
148			This is one byte hexadecimal value. Bit 7 indicates the
149			type of the label attribute; 1 for sensor ID, 0 for
150			ASCII ID. Other bits are reserved.
151extn[1-n]_input
152			6 bytes of hexadecimal data, with a meaning defined by
153			the sensor ID.