[PATCH linux dev-5.8 3/3] hwmon: (sbtsi) Add documentation

[Konstantin Aladyshev]

From: Kun Yi <kunyi at google.com>

Document the SB-TSI sensor interface driver.

Signed-off-by: Kun Yi <kunyi at google.com>
Link: https://lore.kernel.org/r/20201211215427.3281681-3-kunyi@google.com
[groeck: Added SPDX license identifier, same as source]
Signed-off-by: Guenter Roeck <linux at roeck-us.net>
---
 Documentation/hwmon/index.rst      |  1 +
 Documentation/hwmon/sbtsi_temp.rst | 42 ++++++++++++++++++++++++++++++
 2 files changed, 43 insertions(+)
 create mode 100644 Documentation/hwmon/sbtsi_temp.rst

diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index 37e1925735c7..97747457cef3 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -148,6 +148,7 @@ Hardware Monitoring Kernel Drivers
    pxe1610
    pwm-fan
    raspberrypi-hwmon
+   sbtsi_temp
    sch5627
    sch5636
    scpi-hwmon
diff --git a/Documentation/hwmon/sbtsi_temp.rst b/Documentation/hwmon/sbtsi_temp.rst
new file mode 100644
index 000000000000..922b3c8db666
--- /dev/null
+++ b/Documentation/hwmon/sbtsi_temp.rst
@@ -0,0 +1,42 @@
+.. SPDX-License-Identifier: GPL-2.0-or-later
+
+Kernel driver sbtsi_temp
+==================
+
+Supported hardware:
+
+  * Sideband interface (SBI) Temperature Sensor Interface (SB-TSI)
+    compliant AMD SoC temperature device.
+
+    Prefix: 'sbtsi_temp'
+
+    Addresses scanned: This driver doesn't support address scanning.
+
+    To instantiate this driver on an AMD CPU with SB-TSI
+    support, the i2c bus number would be the bus connected from the board
+    management controller (BMC) to the CPU. The i2c address is specified in
+    Section 6.3.1 of the SoC register reference: The SB-TSI address is normally
+    98h for socket 0 and 90h for socket 1, but it could vary based on hardware
+    address select pins.
+
+    Datasheet: The SB-TSI interface and protocol is available as part of
+               the open source SoC register reference at:
+
+	       https://www.amd.com/system/files/TechDocs/56255_OSRR.pdf
+
+               The Advanced Platform Management Link (APML) Specification is
+               available at:
+
+	       http://developer.amd.com/wordpress/media/2012/10/41918.pdf
+
+Author: Kun Yi <kunyi at google.com>
+
+Description
+-----------
+
+The SBI temperature sensor interface (SB-TSI) is an emulation of the software
+and physical interface of a typical 8-pin remote temperature sensor (RTS) on
+AMD SoCs. It implements one temperature sensor with readings and limit
+registers encode the temperature in increments of 0.125 from 0 to 255.875.
+Limits can be set through the writable thresholds, and if reached will trigger
+corresponding alert signals.
-- 
2.25.1