docs: hwmon: Document PECI drivers

Add documentation for peci-cputemp driver that provides DTS thermal
readings for CPU packages and CPU cores, and peci-dimmtemp driver that
provides Temperature Sensor on DIMM readings.

Co-developed-by: Iwona Winiarska <iwona.winiarska@intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
Signed-off-by: Iwona Winiarska <iwona.winiarska@intel.com>
Link: https://lore.kernel.org/r/20220208153639.255278-13-iwona.winiarska@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index df20022c741f1e0621a1a6c7b36dee4c8c3df827..f387f661e1d7eabc0f430d606211895a4ddc9e6a 100644 (file)
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -161,6 +161,8 @@ Hardware Monitoring Kernel Drivers
    pcf8591
    pim4328
    pm6764tr
+   peci-cputemp
+   peci-dimmtemp
    pmbus
    powr1220
    pxe1610

diff --git a/Documentation/hwmon/peci-cputemp.rst b/Documentation/hwmon/peci-cputemp.rst
new file mode 100644 (file)
index 0000000..fe04222
--- /dev/null
+++ b/Documentation/hwmon/peci-cputemp.rst
@@ -0,0 +1,90 @@
+.. SPDX-License-Identifier: GPL-2.0-only
+
+Kernel driver peci-cputemp
+==========================
+
+Supported chips:
+       One of Intel server CPUs listed below which is connected to a PECI bus.
+               * Intel Xeon E5/E7 v3 server processors
+                       Intel Xeon E5-14xx v3 family
+                       Intel Xeon E5-24xx v3 family
+                       Intel Xeon E5-16xx v3 family
+                       Intel Xeon E5-26xx v3 family
+                       Intel Xeon E5-46xx v3 family
+                       Intel Xeon E7-48xx v3 family
+                       Intel Xeon E7-88xx v3 family
+               * Intel Xeon E5/E7 v4 server processors
+                       Intel Xeon E5-16xx v4 family
+                       Intel Xeon E5-26xx v4 family
+                       Intel Xeon E5-46xx v4 family
+                       Intel Xeon E7-48xx v4 family
+                       Intel Xeon E7-88xx v4 family
+               * Intel Xeon Scalable server processors
+                       Intel Xeon D family
+                       Intel Xeon Bronze family
+                       Intel Xeon Silver family
+                       Intel Xeon Gold family
+                       Intel Xeon Platinum family
+
+       Datasheet: Available from http://www.intel.com/design/literature.htm
+
+Author: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
+
+Description
+-----------
+
+This driver implements a generic PECI hwmon feature which provides Digital
+Thermal Sensor (DTS) thermal readings of the CPU package and CPU cores that are
+accessible via the processor PECI interface.
+
+All temperature values are given in millidegree Celsius and will be measurable
+only when the target CPU is powered on.
+
+Sysfs interface
+-------------------
+
+======================= =======================================================
+temp1_label            "Die"
+temp1_input            Provides current die temperature of the CPU package.
+temp1_max              Provides thermal control temperature of the CPU package
+                       which is also known as Tcontrol.
+temp1_crit             Provides shutdown temperature of the CPU package which
+                       is also known as the maximum processor junction
+                       temperature, Tjmax or Tprochot.
+temp1_crit_hyst                Provides the hysteresis value from Tcontrol to Tjmax of
+                       the CPU package.
+
+temp2_label            "DTS"
+temp2_input            Provides current temperature of the CPU package scaled
+                       to match DTS thermal profile.
+temp2_max              Provides thermal control temperature of the CPU package
+                       which is also known as Tcontrol.
+temp2_crit             Provides shutdown temperature of the CPU package which
+                       is also known as the maximum processor junction
+                       temperature, Tjmax or Tprochot.
+temp2_crit_hyst                Provides the hysteresis value from Tcontrol to Tjmax of
+                       the CPU package.
+
+temp3_label            "Tcontrol"
+temp3_input            Provides current Tcontrol temperature of the CPU
+                       package which is also known as Fan Temperature target.
+                       Indicates the relative value from thermal monitor trip
+                       temperature at which fans should be engaged.
+temp3_crit             Provides Tcontrol critical value of the CPU package
+                       which is same to Tjmax.
+
+temp4_label            "Tthrottle"
+temp4_input            Provides current Tthrottle temperature of the CPU
+                       package. Used for throttling temperature. If this value
+                       is allowed and lower than Tjmax - the throttle will
+                       occur and reported at lower than Tjmax.
+
+temp5_label            "Tjmax"
+temp5_input            Provides the maximum junction temperature, Tjmax of the
+                       CPU package.
+
+temp[6-N]_label                Provides string "Core X", where X is resolved core
+                       number.
+temp[6-N]_input                Provides current temperature of each core.
+
+======================= =======================================================

diff --git a/Documentation/hwmon/peci-dimmtemp.rst b/Documentation/hwmon/peci-dimmtemp.rst
new file mode 100644 (file)
index 0000000..e562aed
--- /dev/null
+++ b/Documentation/hwmon/peci-dimmtemp.rst
@@ -0,0 +1,57 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Kernel driver peci-dimmtemp
+===========================
+
+Supported chips:
+       One of Intel server CPUs listed below which is connected to a PECI bus.
+               * Intel Xeon E5/E7 v3 server processors
+                       Intel Xeon E5-14xx v3 family
+                       Intel Xeon E5-24xx v3 family
+                       Intel Xeon E5-16xx v3 family
+                       Intel Xeon E5-26xx v3 family
+                       Intel Xeon E5-46xx v3 family
+                       Intel Xeon E7-48xx v3 family
+                       Intel Xeon E7-88xx v3 family
+               * Intel Xeon E5/E7 v4 server processors
+                       Intel Xeon E5-16xx v4 family
+                       Intel Xeon E5-26xx v4 family
+                       Intel Xeon E5-46xx v4 family
+                       Intel Xeon E7-48xx v4 family
+                       Intel Xeon E7-88xx v4 family
+               * Intel Xeon Scalable server processors
+                       Intel Xeon D family
+                       Intel Xeon Bronze family
+                       Intel Xeon Silver family
+                       Intel Xeon Gold family
+                       Intel Xeon Platinum family
+
+       Datasheet: Available from http://www.intel.com/design/literature.htm
+
+Author: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
+
+Description
+-----------
+
+This driver implements a generic PECI hwmon feature which provides
+Temperature sensor on DIMM readings that are accessible via the processor PECI interface.
+
+All temperature values are given in millidegree Celsius and will be measurable
+only when the target CPU is powered on.
+
+Sysfs interface
+-------------------
+
+======================= =======================================================
+
+temp[N]_label          Provides string "DIMM CI", where C is DIMM channel and
+                       I is DIMM index of the populated DIMM.
+temp[N]_input          Provides current temperature of the populated DIMM.
+temp[N]_max            Provides thermal control temperature of the DIMM.
+temp[N]_crit           Provides shutdown temperature of the DIMM.
+
+======================= =======================================================
+
+Note:
+       DIMM temperature attributes will appear when the client CPU's BIOS
+       completes memory training and testing.

diff --git a/MAINTAINERS b/MAINTAINERS
index dbf2bb23a15f91778cb8180fd6cecf10fc117562..b7992853a427f68bffc6d685849377c57314eb86 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -15108,6 +15108,8 @@ PECI HARDWARE MONITORING DRIVERS
 M:     Iwona Winiarska <iwona.winiarska@intel.com>
 L:     linux-hwmon@vger.kernel.org
 S:     Supported
+F:     Documentation/hwmon/peci-cputemp.rst
+F:     Documentation/hwmon/peci-dimmtemp.rst
 F:     drivers/hwmon/peci/
 
 PECI SUBSYSTEM