[PATCH v4 2/9] Documentation: hwmon: Add OCC documentation

From: Eddie James
Date: Wed Jul 11 2018 - 17:03:32 EST


Document the hwmon interface for the OCC.

Signed-off-by: Eddie James <eajames@xxxxxxxxxxxxxxxxxx>
---
Documentation/hwmon/occ | 73 +++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 73 insertions(+)
create mode 100644 Documentation/hwmon/occ

diff --git a/Documentation/hwmon/occ b/Documentation/hwmon/occ
new file mode 100644
index 0000000..465fa1a
--- /dev/null
+++ b/Documentation/hwmon/occ
@@ -0,0 +1,73 @@
+Kernel driver occ-hwmon
+=======================
+
+Supported chips:
+ * POWER8
+ * POWER9
+
+Author: Eddie James <eajames@xxxxxxxxxxxxxxxxxx>
+
+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.
+
+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.
--
1.8.3.1