[PATCH linux dev-4.10 5/6] Documentation: hwmon: Add a generic PECI hwmon

From: Jae Hyun Yoo
Date: Tue Jan 09 2018 - 17:32:24 EST


From: Jae Hyun Yoo <jae.hyun.yoo@xxxxxxxxx>

This commit add a document for a generic PECI hwmon driver.

Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@xxxxxxxxx>
---
Documentation/hwmon/peci-hwmon | 74 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 74 insertions(+)
create mode 100644 Documentation/hwmon/peci-hwmon

diff --git a/Documentation/hwmon/peci-hwmon b/Documentation/hwmon/peci-hwmon
new file mode 100644
index 0000000..e0155b5
--- /dev/null
+++ b/Documentation/hwmon/peci-hwmon
@@ -0,0 +1,74 @@
+Kernel driver peci-hwmon
+===============================
+
+Supported chips:
+ Generic BMC chips provide PECI controller
+
+Author:
+ Jae Hyun Yoo <jae.hyun.yoo@xxxxxxxxxxxxxxx>
+
+
+Hardware Interfaces
+-------------------
+
+This driver uses a PECI misc driver as a controller interface so one of PECI
+misc drivers which provides compatible ioctls has to be enabled.
+
+
+Description
+-----------
+
+This driver implements a generic PECI hwmon feature which is running with a PECI
+controller driver supports native PECI Client Command Suite for retrieving
+temperatures of the CPU package, CPU cores and DIMM components.
+
+All temperature values are given in millidegree Celsius and will be measurable
+only when the target CPU is powered on.
+
+
+sysfs files
+-----------
+
+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_input Provides current DTS thermal margin to Tcontrol of the
+ CPU package. Value 0 means it reaches to Tcontrol
+ temperature. Sub-zero value means the die temperature
+ goes across Tconrtol to Tjmax.
+temp2_min Provides the minimum DTS thermal margin to Tcontrol of
+ the CPU package.
+temp2_lcrit Provides the value when the CPU package temperature
+ reaches to Tjmax.
+
+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_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.
+
+temp[100-127]_input Provides current core temperature.
+temp[100-127]_max Provides thermal control temperature of the core.
+temp[100-127]_crit Provides shutdown temperature of the core.
+temp[100-127]_crit_hyst Provides the hysteresis value from Tcontrol to Tjmax of
+ the core.
+
+Note:
+ Core temperature group will be appeared when probing the driver if CPU
+ is online or when the first reading on other attr happens because it
+ needs cpu info reading. The number of generated core attrs depends on
+ the number of cores of the cpu package.
+
+temp[200-215]_input Provides current temperature of the DDR DIMM.
--
2.7.4