1 .. SPDX-License-Identifier: GPL-2.0-only 2 3 ======== 4 Overview 5 ======== 6 7 The Platform Environment Control Interface (PECI) is a communication 8 interface between Intel processor and management controllers 9 (e.g. Baseboard Management Controller, BMC). 10 PECI provides services that allow the management controller to 11 configure, monitor and debug platform by accessing various registers. 12 It defines a dedicated command protocol, where the management 13 controller is acting as a PECI originator and the processor - as 14 a PECI responder. 15 PECI can be used in both single processor and multiple-processor based 16 systems. 17 18 NOTE: 19 Intel PECI specification is not released as a dedicated document, 20 instead it is a part of External Design Specification (EDS) for given 21 Intel CPU. External Design Specifications are usually not publicly 22 available. 23 24 PECI Wire 25 --------- 26 27 PECI Wire interface uses a single wire for self-clocking and data 28 transfer. It does not require any additional control lines - the 29 physical layer is a self-clocked one-wire bus signal that begins each 30 bit with a driven, rising edge from an idle near zero volts. The 31 duration of the signal driven high allows to determine whether the bit 32 value is logic '0' or logic '1'. PECI Wire also includes variable data 33 rate established with every message. 34 35 For PECI Wire, each processor package will utilize unique, fixed 36 addresses within a defined range and that address should 37 have a fixed relationship with the processor socket ID - if one of the 38 processors is removed, it does not affect addresses of remaining 39 processors. 40 41 PECI subsystem internals 42 ------------------------ 43 44 .. kernel-doc:: include/linux/peci.h 45 .. kernel-doc:: drivers/peci/internal.h 46 .. kernel-doc:: drivers/peci/core.c 47 .. kernel-doc:: drivers/peci/request.c 48 49 PECI CPU Driver API 50 ------------------- 51 .. kernel-doc:: drivers/peci/cpu.c
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.