On Mon, Aug 14, 2017 at 02:26:20PM -0500, Eddie James wrote:
Good question. Are the limits documented ? If yes, that would make sense.
On 08/14/2017 01:53 PM, Guenter Roeck wrote:
On Mon, Aug 14, 2017 at 10:26:30AM -0500, Eddie James wrote:Thanks, I better change this doc to "alarm." The spec reports all these as
From: "Edward A. James" <eajames@xxxxxxxxxx>Just noticed. Are you sure you mean 'fault' here and below ?
Signed-off-by: Edward A. James <eajames@xxxxxxxxxx>
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Documentation/hwmon/ibm-cffps | 54 +++++++++++++++++++++++++++++++++++++++++++
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create mode 100644 Documentation/hwmon/ibm-cffps
diff --git a/Documentation/hwmon/ibm-cffps b/Documentation/hwmon/ibm-cffps
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+Kernel driver ibm-cffps
+=======================
+
+Supported chips:
+ * IBM Common Form Factor power supply
+
+Author: Eddie James <eajames@xxxxxxxxxx>
+
+Description
+-----------
+
+This driver supports IBM Common Form Factor (CFF) power supplies. This driver
+is a client to the core PMBus driver.
+
+Usage Notes
+-----------
+
+This driver does not auto-detect devices. You will have to instantiate the
+devices explicitly. Please see Documentation/i2c/instantiating-devices for
+details.
+
+Sysfs entries
+-------------
+
+The following attributes are supported:
+
+curr1_alarm Output current over-current fault.
+curr1_input Measured output current in mA.
+curr1_label "iout1"
+
+fan1_alarm Fan 1 warning.
+fan1_fault Fan 1 fault.
+fan1_input Fan 1 speed in RPM.
+fan2_alarm Fan 2 warning.
+fan2_fault Fan 2 fault.
+fan2_input Fan 2 speed in RPM.
+
+in1_alarm Input voltage under-voltage fault.
'alarm' attributes normally report an over- or under- condition,
but not a fault. Faults should be reported with 'fault' attributes.
In PMBus lingo (which doesn't distinguish a real 'fault' from
a critical over- or under- condition), the "FAULT" condition
usually maps with the 'crit_alarm' or 'lcrit_alarm' attributes.
Also, under-voltages would normally be reported as min_alarm
or clrit_alarm, not in_alarm.
"faults" but many of them are merely over-temp or over-voltage, etc, and
should be "alarm" to be consistent with PMBus.
The problem with this power supply is that it doesn't report any "limits."
So unless I set up my read_byte function to return some limits, we can't get
any lower or upper limits and therefore won't get the crit_alarm,
lcrit_alarm, etc. Do you think I should "fake" the limits in the driver?
I am quite sure that limits are word registers, though.
Guenter
Hm, with my latest changes to look at the higher byte of STATUS_WORD, it+in1_input Measured input voltage in mV.Another example; this maps to PMBUS_PIN_OP_WARN_LIMIT which is an
+in1_label "vin"
+in2_alarm Output voltage over-voltage fault.
+in2_input Measured output voltage in mV.
+in2_label "vout1"
+
+power1_alarm Input fault.
input power alarm, not an indication of a fault condition.
looks like we now have the same name for both the pin generic alarm
attribute and the pin_limit_attr... So in this device's case, it would map
to PB_STATUS_INPUT bit of STATUS_WORD. Didn't think about that... any
suggestions? Can't really change the name of the limit one without breaking
people's code...
Will change these to "alarm" in the doc too.+power1_input Measured input power in uW.Interestingly, PMBus does not distinguish between a critical temperature
+power1_label "pin"
+
+temp1_alarm PSU inlet ambient temperature over-temperature fault.
+temp1_input Measured PSU inlet ambient temp in millidegrees C.
+temp2_alarm Secondary rectifier temp over-temperature fault.
alarm and an actual "fault". Makes me wonder if the IBM PS reports
CFFPS_MFR_THERMAL_FAULT if there is an actual fault (chip or sensor failure),
or if it has the same meaning as PB_TEMP_OT_FAULT, ie an excessively high
temperature.
If it is a real fault (a detected sensor failure), we should possiblyYea, that would probably be helpful. The CFFPS_MFR_THERMAL_FAULT bit is a
consider adding a respective "virtual" temperature status flag. The same
is true for other status bits reported in the manufacturer status
register if any of those reflect a "real" fault, ie a chip failure.
fault (so the spec says), but I'm not sure what is triggering it.
Thanks,
Eddie
+temp2_input Measured secondary rectifier temp in millidegrees C.
+temp3_alarm ORing FET temperature over-temperature fault.
+temp3_input Measured ORing FET temperature in millidegrees C.
--
1.8.3.1