path: root/Documentation
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authorLinus Torvalds <>2014-04-02 14:27:15 -0700
committerLinus Torvalds <>2014-04-02 14:27:15 -0700
commitb9f2b21a32906a47c220b5167b88869f2c90f1c4 (patch)
tree96416cec877f9c1f2ee0f0ccdee64e38cc8e0683 /Documentation
parent70f6c087573eeb406252ff8d98f511eb5f71496e (diff)
parenta0e7398357f297dd22d043fb2d5aa1c44d61ca10 (diff)
Merge tag 'dt-for-linus' of git://
Pull devicetree changes from Grant Likely: "Updates to devicetree core code. This branch contains the following notable changes: - add reserved memory binding - make struct device_node a kobject and remove legacy /proc/device-tree - ePAPR conformance fixes - update in-kernel DTC copy to version v1.4.0 - preparatory changes for dynamic device tree overlays - minor bug fixes and documentation changes The most significant change in this branch is the conversion of struct device_node to be a kobject that is exposed via sysfs and removal of the old /proc/device-tree code. This simplifies the device tree handling code and tightens up the lifecycle on device tree nodes. [updated: added fix for dangling select PROC_DEVICETREE]" * tag 'dt-for-linus' of git:// (29 commits) dt: Remove dangling "select PROC_DEVICETREE" of: Add support for ePAPR "stdout-path" property of: device_node kobject lifecycle fixes of: only scan for reserved mem when fdt present powerpc: add support for reserved memory defined by device tree arm64: add support for reserved memory defined by device tree of: add missing major vendors of: add vendor prefix for SMSC of: remove /proc/device-tree of/selftest: Add self tests for manipulation of properties of: Make device nodes kobjects so they show up in sysfs arm: add support for reserved memory defined by device tree drivers: of: add support for custom reserved memory drivers drivers: of: add initialization code for dynamic reserved memory drivers: of: add initialization code for static reserved memory of: document bindings for reserved-memory nodes Revert "of: fix of_update_property()" kbuild: dtbs_install: new make target ARM: mvebu: Allows to get the SoC ID even without PCI enabled of: Allows to use the PCI translator without the PCI core ...
Diffstat (limited to 'Documentation')
3 files changed, 178 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-firmware-ofw b/Documentation/ABI/testing/sysfs-firmware-ofw
new file mode 100644
index 000000000000..f562b188e71d
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-firmware-ofw
@@ -0,0 +1,28 @@
+What: /sys/firmware/devicetree/*
+Date: November 2013
+Contact: Grant Likely <>
+ When using OpenFirmware or a Flattened Device Tree to enumerate
+ hardware, the device tree structure will be exposed in this
+ directory.
+ It is possible for multiple device-tree directories to exist.
+ Some device drivers use a separate detached device tree which
+ have no attachment to the system tree and will appear in a
+ different subdirectory under /sys/firmware/devicetree.
+ Userspace must not use the /sys/firmware/devicetree/base
+ path directly, but instead should follow /proc/device-tree
+ symlink. It is possible that the absolute path will change
+ in the future, but the symlink is the stable ABI.
+ The /proc/device-tree symlink replaces the devicetree /proc
+ filesystem support, and has largely the same semantics and
+ should be compatible with existing userspace.
+ The contents of /sys/firmware/devicetree/ is a
+ hierarchy of directories, one per device tree node. The
+ directory name is the resolved path component name (node
+ name plus address). Properties are represented as files
+ in the directory. The contents of each file is the exact
+ binary data from the device tree.
diff --git a/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt b/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
new file mode 100644
index 000000000000..3da0ebdba8d9
--- /dev/null
+++ b/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
@@ -0,0 +1,133 @@
+*** Reserved memory regions ***
+Reserved memory is specified as a node under the /reserved-memory node.
+The operating system shall exclude reserved memory from normal usage
+one can create child nodes describing particular reserved (excluded from
+normal use) memory regions. Such memory regions are usually designed for
+the special usage by various device drivers.
+Parameters for each memory region can be encoded into the device tree
+with the following nodes:
+/reserved-memory node
+#address-cells, #size-cells (required) - standard definition
+ - Should use the same values as the root node
+ranges (required) - standard definition
+ - Should be empty
+/reserved-memory/ child nodes
+Each child of the reserved-memory node specifies one or more regions of
+reserved memory. Each child node may either use a 'reg' property to
+specify a specific range of reserved memory, or a 'size' property with
+optional constraints to request a dynamically allocated block of memory.
+Following the generic-names recommended practice, node names should
+reflect the purpose of the node (ie. "framebuffer" or "dma-pool"). Unit
+address (@<address>) should be appended to the name if the node is a
+static allocation.
+Requires either a) or b) below.
+a) static allocation
+ reg (required) - standard definition
+b) dynamic allocation
+ size (required) - length based on parent's #size-cells
+ - Size in bytes of memory to reserve.
+ alignment (optional) - length based on parent's #size-cells
+ - Address boundary for alignment of allocation.
+ alloc-ranges (optional) - prop-encoded-array (address, length pairs).
+ - Specifies regions of memory that are
+ acceptable to allocate from.
+If both reg and size are present, then the reg property takes precedence
+and size is ignored.
+Additional properties:
+compatible (optional) - standard definition
+ - may contain the following strings:
+ - shared-dma-pool: This indicates a region of memory meant to be
+ used as a shared pool of DMA buffers for a set of devices. It can
+ be used by an operating system to instanciate the necessary pool
+ management subsystem if necessary.
+ - vendor specific string in the form <vendor>,[<device>-]<usage>
+no-map (optional) - empty property
+ - Indicates the operating system must not create a virtual mapping
+ of the region as part of its standard mapping of system memory,
+ nor permit speculative access to it under any circumstances other
+ than under the control of the device driver using the region.
+reusable (optional) - empty property
+ - The operating system can use the memory in this region with the
+ limitation that the device driver(s) owning the region need to be
+ able to reclaim it back. Typically that means that the operating
+ system can use that region to store volatile or cached data that
+ can be otherwise regenerated or migrated elsewhere.
+Linux implementation note:
+- If a "linux,cma-default" property is present, then Linux will use the
+ region for the default pool of the contiguous memory allocator.
+Device node references to reserved memory
+Regions in the /reserved-memory node may be referenced by other device
+nodes by adding a memory-region property to the device node.
+memory-region (optional) - phandle, specifier pairs to children of /reserved-memory
+This example defines 3 contiguous regions are defined for Linux kernel:
+one default of all device drivers (named linux,cma@72000000 and 64MiB in size),
+one dedicated to the framebuffer device (named framebuffer@78000000, 8MiB), and
+one for multimedia processing (named multimedia-memory@77000000, 64MiB).
+/ {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ memory {
+ reg = <0x40000000 0x40000000>;
+ };
+ reserved-memory {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ ranges;
+ /* global autoconfigured region for contiguous allocations */
+ linux,cma {
+ compatible = "shared-dma-pool";
+ reusable;
+ size = <0x4000000>;
+ alignment = <0x2000>;
+ linux,cma-default;
+ };
+ display_reserved: framebuffer@78000000 {
+ reg = <0x78000000 0x800000>;
+ };
+ multimedia_reserved: multimedia@77000000 {
+ compatible = "acme,multimedia-memory";
+ reg = <0x77000000 0x4000000>;
+ };
+ };
+ /* ... */
+ fb0: video@12300000 {
+ memory-region = <&display_reserved>;
+ /* ... */
+ };
+ scaler: scaler@12500000 {
+ memory-region = <&multimedia_reserved>;
+ /* ... */
+ };
+ codec: codec@12600000 {
+ memory-region = <&multimedia_reserved>;
+ /* ... */
+ };
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt
index 40ce2df0e0e9..95465d57eb31 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.txt
+++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
@@ -3,6 +3,7 @@ Device tree binding vendor prefix registry. Keep list in alphabetical order.
This isn't an exhaustive list, but you should add new prefixes to it before
using them to avoid name-space collisions.
+abilis Abilis Systems
active-semi Active-Semi International Inc
ad Avionic Design GmbH
adi Analog Devices, Inc.
@@ -11,14 +12,17 @@ ak Asahi Kasei Corp.
allwinner Allwinner Technology Co., Ltd.
altr Altera Corp.
amcc Applied Micro Circuits Corporation (APM, formally AMCC)
+amd Advanced Micro Devices (AMD), Inc.
amstaos AMS-Taos Inc.
apm Applied Micro Circuits Corporation (APM)
arm ARM Ltd.
+armadeus ARMadeus Systems SARL
atmel Atmel Corporation
auo AU Optronics Corporation
avago Avago Technologies
bosch Bosch Sensortec GmbH
brcm Broadcom Corporation
+calxeda Calxeda
capella Capella Microsystems, Inc
cavium Cavium, Inc.
cdns Cadence Design Systems Inc.
@@ -26,8 +30,10 @@ chrp Common Hardware Reference Platform
chunghwa Chunghwa Picture Tubes Ltd.
cirrus Cirrus Logic, Inc.
cortina Cortina Systems, Inc.
+crystalfontz Crystalfontz America, Inc.
dallas Maxim Integrated Products (formerly Dallas Semiconductor)
davicom DAVICOM Semiconductor, Inc.
+dlink D-Link Systems, Inc.
denx Denx Software Engineering
edt Emerging Display Technologies
emmicro EM Microelectronic
@@ -37,7 +43,9 @@ est ESTeem Wireless Modems
fsl Freescale Semiconductor
GEFanuc GE Fanuc Intelligent Platforms Embedded Systems, Inc.
gef GE Fanuc Intelligent Platforms Embedded Systems, Inc.
+globalscale Globalscale Technologies, Inc.
gmt Global Mixed-mode Technology, Inc.
+google Google, Inc.
gumstix Gumstix, Inc.
haoyu Haoyu Microelectronic Co. Ltd.
hisilicon Hisilicon Limited.
@@ -46,9 +54,12 @@ hp Hewlett Packard
ibm International Business Machines (IBM)
idt Integrated Device Technologies, Inc.
img Imagination Technologies Ltd.
+intel Intel Corporation
intercontrol Inter Control Group
isl Intersil
karo Ka-Ro electronics GmbH
+lacie LaCie
+lantiq Lantiq Semiconductor
lg LG Corporation
linux Linux-specific binding
lsi LSI Corp. (LSI Logic)
@@ -56,12 +67,16 @@ marvell Marvell Technology Group Ltd.
maxim Maxim Integrated Products
microchip Microchip Technology Inc.
mosaixtech Mosaix Technologies, Inc.
+moxa Moxa
national National Semiconductor
neonode Neonode Inc.
+netgear NETGEAR
nintendo Nintendo
+nokia Nokia
nvidia NVIDIA
nxp NXP Semiconductors
onnn ON Semiconductor Corp.
panasonic Panasonic Corporation
phytec PHYTEC Messtechnik GmbH
picochip Picochip Ltd
@@ -80,6 +95,7 @@ sil Silicon Image
silabs Silicon Laboratories
sirf SiRF Technology, Inc.
+smsc Standard Microsystems Corporation
snps Synopsys, Inc.
spansion Spansion Inc.
st STMicroelectronics
@@ -94,4 +110,5 @@ via VIA Technologies, Inc.
winbond Winbond Electronics corp.
wlf Wolfson Microelectronics
wm Wondermedia Technologies, Inc.
+xes Extreme Engineering Solutions (X-ES)
xlnx Xilinx