From 6ec3fcf556fe44542934b778aea1b725b0793418 Mon Sep 17 00:00:00 2001 From: Kun Yi Date: Fri, 11 Dec 2020 13:54:26 -0800 Subject: [PATCH] hwmon: (sbtsi) Add documentation Document the SB-TSI sensor interface driver. Signed-off-by: Kun Yi 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 --- 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 7e5104c8f477..fcb870ce6286 100644 --- a/Documentation/hwmon/index.rst +++ b/Documentation/hwmon/index.rst @@ -154,6 +154,7 @@ Hardware Monitoring Kernel Drivers pwm-fan q54sj108a2 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 + +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.