0001 Kernel driver occ-hwmon
0002 =======================
0003
0004 Supported chips:
0005
0006 * POWER8
0007 * POWER9
0008
0009 Author: Eddie James <eajames@linux.ibm.com>
0010
0011 Description
0012 -----------
0013
0014 This driver supports hardware monitoring for the On-Chip Controller (OCC)
0015 embedded on POWER processors. The OCC is a device that collects and aggregates
0016 sensor data from the processor and the system. The OCC can provide the raw
0017 sensor data as well as perform thermal and power management on the system.
0018
0019 The P8 version of this driver is a client driver of I2C. It may be probed
0020 manually if an "ibm,p8-occ-hwmon" compatible device is found under the
0021 appropriate I2C bus node in the device-tree.
0022
0023 The P9 version of this driver is a client driver of the FSI-based OCC driver.
0024 It will be probed automatically by the FSI-based OCC driver.
0025
0026 Sysfs entries
0027 -------------
0028
0029 The following attributes are supported. All attributes are read-only unless
0030 specified.
0031
0032 The OCC sensor ID is an integer that represents the unique identifier of the
0033 sensor with respect to the OCC. For example, a temperature sensor for the third
0034 DIMM slot in the system may have a sensor ID of 7. This mapping is unavailable
0035 to the device driver, which must therefore export the sensor ID as-is.
0036
0037 Some entries are only present with certain OCC sensor versions or only on
0038 certain OCCs in the system. The version number is not exported to the user
0039 but can be inferred.
0040
0041 temp[1-n]_label
0042 OCC sensor ID.
0043
0044 [with temperature sensor version 1]
0045
0046 temp[1-n]_input
0047 Measured temperature of the component in millidegrees
0048 Celsius.
0049
0050 [with temperature sensor version >= 2]
0051
0052 temp[1-n]_type
0053 The FRU (Field Replaceable Unit) type
0054 (represented by an integer) for the component
0055 that this sensor measures.
0056 temp[1-n]_fault
0057 Temperature sensor fault boolean; 1 to indicate
0058 that a fault is present or 0 to indicate that
0059 no fault is present.
0060
0061 [with type == 3 (FRU type is VRM)]
0062
0063 temp[1-n]_alarm
0064 VRM temperature alarm boolean; 1 to indicate
0065 alarm, 0 to indicate no alarm
0066
0067 [else]
0068
0069 temp[1-n]_input
0070 Measured temperature of the component in
0071 millidegrees Celsius.
0072
0073 freq[1-n]_label
0074 OCC sensor ID.
0075 freq[1-n]_input
0076 Measured frequency of the component in MHz.
0077 power[1-n]_input
0078 Latest measured power reading of the component in
0079 microwatts.
0080 power[1-n]_average
0081 Average power of the component in microwatts.
0082 power[1-n]_average_interval
0083 The amount of time over which the power average
0084 was taken in microseconds.
0085
0086 [with power sensor version < 2]
0087
0088 power[1-n]_label
0089 OCC sensor ID.
0090
0091 [with power sensor version >= 2]
0092
0093 power[1-n]_label
0094 OCC sensor ID + function ID + channel in the form
0095 of a string, delimited by underscores, i.e. "0_15_1".
0096 Both the function ID and channel are integers that
0097 further identify the power sensor.
0098
0099 [with power sensor version 0xa0]
0100
0101 power[1-n]_label
0102 OCC sensor ID + sensor type in the form of a string,
0103 delimited by an underscore, i.e. "0_system". Sensor
0104 type will be one of "system", "proc", "vdd" or "vdn".
0105 For this sensor version, OCC sensor ID will be the same
0106 for all power sensors.
0107
0108 [present only on "master" OCC; represents the whole system power; only one of
0109 this type of power sensor will be present]
0110
0111 power[1-n]_label
0112 "system"
0113 power[1-n]_input
0114 Latest system output power in microwatts.
0115 power[1-n]_cap
0116 Current system power cap in microwatts.
0117 power[1-n]_cap_not_redundant
0118 System power cap in microwatts when
0119 there is not redundant power.
0120 power[1-n]_cap_max
0121 Maximum power cap that the OCC can enforce in
0122 microwatts.
0123 power[1-n]_cap_min Minimum power cap that the OCC can enforce in
0124 microwatts.
0125 power[1-n]_cap_user The power cap set by the user, in microwatts.
0126 This attribute will return 0 if no user power
0127 cap has been set. This attribute is read-write,
0128 but writing any precision below watts will be
0129 ignored, i.e. requesting a power cap of
0130 500900000 microwatts will result in a power cap
0131 request of 500 watts.
0132
0133 [with caps sensor version > 1]
0134
0135 power[1-n]_cap_user_source
0136 Indicates how the user power cap was
0137 set. This is an integer that maps to
0138 system or firmware components that can
0139 set the user power cap.
0140
0141 The following "extn" sensors are exported as a way for the OCC to provide data
0142 that doesn't fit anywhere else. The meaning of these sensors is entirely
0143 dependent on their data, and cannot be statically defined.
0144
0145 extn[1-n]_label
0146 ASCII ID or OCC sensor ID.
0147 extn[1-n]_flags
0148 This is one byte hexadecimal value. Bit 7 indicates the
0149 type of the label attribute; 1 for sensor ID, 0 for
0150 ASCII ID. Other bits are reserved.
0151 extn[1-n]_input
0152 6 bytes of hexadecimal data, with a meaning defined by
0153 the sensor ID.
