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authorLinus Torvalds <torvalds@linux-foundation.org>2022-03-28 12:27:35 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2022-03-28 12:27:35 -0700
commit02e2af20f4f9f2aa0c84e9a30a35c02f0fbb7daa (patch)
treed126449a7d2ea2270627183f7cebd726fbe56a9d /Documentation/peci
parentff61bc81b3feebcef4d0431a92e2e40e8d4fe8b3 (diff)
parent37fd83916da2e4cae03d350015c82a67b1b334c4 (diff)
Merge tag 'char-misc-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc and other driver updates from Greg KH: "Here is the big set of char/misc and other small driver subsystem updates for 5.18-rc1. Included in here are merges from driver subsystems which contain: - iio driver updates and new drivers - fsi driver updates - fpga driver updates - habanalabs driver updates and support for new hardware - soundwire driver updates and new drivers - phy driver updates and new drivers - coresight driver updates - icc driver updates Individual changes include: - mei driver updates - interconnect driver updates - new PECI driver subsystem added - vmci driver updates - lots of tiny misc/char driver updates All of these have been in linux-next for a while with no reported problems" * tag 'char-misc-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (556 commits) firmware: google: Properly state IOMEM dependency kgdbts: fix return value of __setup handler firmware: sysfb: fix platform-device leak in error path firmware: stratix10-svc: add missing callback parameter on RSU arm64: dts: qcom: add non-secure domain property to fastrpc nodes misc: fastrpc: Add dma handle implementation misc: fastrpc: Add fdlist implementation misc: fastrpc: Add helper function to get list and page misc: fastrpc: Add support to secure memory map dt-bindings: misc: add fastrpc domain vmid property misc: fastrpc: check before loading process to the DSP misc: fastrpc: add secure domain support dt-bindings: misc: add property to support non-secure DSP misc: fastrpc: Add support to get DSP capabilities misc: fastrpc: add support for FASTRPC_IOCTL_MEM_MAP/UNMAP misc: fastrpc: separate fastrpc device from channel context dt-bindings: nvmem: brcm,nvram: add basic NVMEM cells dt-bindings: nvmem: make "reg" property optional nvmem: brcm_nvram: parse NVRAM content into NVMEM cells nvmem: dt-bindings: Fix the error of dt-bindings check ...
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+.. SPDX-License-Identifier: GPL-2.0-only
+
+====================
+Linux PECI Subsystem
+====================
+
+.. toctree::
+
+ peci
+
+.. only:: subproject and html
+
+ Indices
+ =======
+
+ * :ref:`genindex`
diff --git a/Documentation/peci/peci.rst b/Documentation/peci/peci.rst
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+.. SPDX-License-Identifier: GPL-2.0-only
+
+========
+Overview
+========
+
+The Platform Environment Control Interface (PECI) is a communication
+interface between Intel processor and management controllers
+(e.g. Baseboard Management Controller, BMC).
+PECI provides services that allow the management controller to
+configure, monitor and debug platform by accessing various registers.
+It defines a dedicated command protocol, where the management
+controller is acting as a PECI originator and the processor - as
+a PECI responder.
+PECI can be used in both single processor and multiple-processor based
+systems.
+
+NOTE:
+Intel PECI specification is not released as a dedicated document,
+instead it is a part of External Design Specification (EDS) for given
+Intel CPU. External Design Specifications are usually not publicly
+available.
+
+PECI Wire
+---------
+
+PECI Wire interface uses a single wire for self-clocking and data
+transfer. It does not require any additional control lines - the
+physical layer is a self-clocked one-wire bus signal that begins each
+bit with a driven, rising edge from an idle near zero volts. The
+duration of the signal driven high allows to determine whether the bit
+value is logic '0' or logic '1'. PECI Wire also includes variable data
+rate established with every message.
+
+For PECI Wire, each processor package will utilize unique, fixed
+addresses within a defined range and that address should
+have a fixed relationship with the processor socket ID - if one of the
+processors is removed, it does not affect addresses of remaining
+processors.
+
+PECI subsystem internals
+------------------------
+
+.. kernel-doc:: include/linux/peci.h
+.. kernel-doc:: drivers/peci/internal.h
+.. kernel-doc:: drivers/peci/core.c
+.. kernel-doc:: drivers/peci/request.c
+
+PECI CPU Driver API
+-------------------
+.. kernel-doc:: drivers/peci/cpu.c