aboutsummaryrefslogtreecommitdiffstats
path: root/Documentation
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2014-10-11 06:47:50 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2014-10-11 06:47:50 -0400
commite98d6e7f7625ed60c7bc1d39aeb2375ed3918fd5 (patch)
treebc6e9a6428229d2fca73e1447b5cbfe59866c4b4 /Documentation
parent4e0b7fe38345b81930363b9f1b4b324181ddcc9e (diff)
parent2118f4b8dfc666c3e4a9e262beca79636a0852fe (diff)
Merge tag 'devicetree-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/glikely/linux
Pull devicetree changes from Grant Likely: "This branch contains bug fixes and new features for the devicetree code. Most of the changes are either new testcases for the selftest code or documentation changes. The most notable change is the addition of a phandle resolver for use when grafting in a second device tree blob into the core tree. The resolver isn't currently used by anything other than the selftest module, but it will be used to support device tree overlays; probably in the v3.19 timeframe. Also note that I've moved my normal tree from git.secretlab.ca to git.kernel.org" * tag 'devicetree-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/glikely/linux: of/selftest: Move hash table off stack to fix large frame size To remove non-ascii characters in of_selftest.txt of/selftest: Use the resolver to fixup phandles of: Introduce Device Tree resolve support. of/selftest: Add a test for duplicate phandles of: Don't try to search when phandle == 0 of/selftest: Test structure of device tree of: Fix NULL dereference in selftest removal code of: add vendor prefix for Chipidea of: Add vendor prefix for Innolux Corporation of: Add vendor prefix for Sitronix devicetree: bindings: Document Gateworks vendor prefix of: Add vendor prefix for Energy Micro dt/documentation: add specification of dma bus information
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/devicetree/bindings/vendor-prefixes.txt4
-rw-r--r--Documentation/devicetree/booting-without-of.txt53
-rw-r--r--Documentation/devicetree/dynamic-resolution-notes.txt25
-rw-r--r--Documentation/devicetree/of_selftest.txt30
4 files changed, 97 insertions, 15 deletions
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt
index 71259df60e96..f67e3f84e8bc 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.txt
+++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
@@ -46,6 +46,7 @@ dmo Data Modul AG
ebv EBV Elektronik
edt Emerging Display Technologies
emmicro EM Microelectronic
+energymicro Silicon Laboratories (formerly Energy Micro AS)
epcos EPCOS AG
epfl Ecole Polytechnique Fédérale de Lausanne
epson Seiko Epson Corp.
@@ -62,6 +63,7 @@ globalscale Globalscale Technologies, Inc.
gmt Global Mixed-mode Technology, Inc.
google Google, Inc.
gumstix Gumstix, Inc.
+gw Gateworks Corporation
haoyu Haoyu Microelectronic Co. Ltd.
hisilicon Hisilicon Limited.
honeywell Honeywell
@@ -71,6 +73,7 @@ ibm International Business Machines (IBM)
idt Integrated Device Technologies, Inc.
iom Iomega Corporation
img Imagination Technologies Ltd.
+innolux Innolux Corporation
intel Intel Corporation
intercontrol Inter Control Group
isee ISEE 2007 S.L.
@@ -132,6 +135,7 @@ simtek
sii Seiko Instruments, Inc.
silergy Silergy Corp.
sirf SiRF Technology, Inc.
+sitronix Sitronix Technology Corporation
smsc Standard Microsystems Corporation
snps Synopsys, Inc.
solidrun SolidRun
diff --git a/Documentation/devicetree/booting-without-of.txt b/Documentation/devicetree/booting-without-of.txt
index 1f013bd0d320..77685185cf3b 100644
--- a/Documentation/devicetree/booting-without-of.txt
+++ b/Documentation/devicetree/booting-without-of.txt
@@ -51,6 +51,8 @@ Table of Contents
VIII - Specifying device power management information (sleep property)
+ IX - Specifying dma bus information
+
Appendix A - Sample SOC node for MPC8540
@@ -1332,6 +1334,57 @@ reasonably grouped in this manner, then create a virtual sleep controller
(similar to an interrupt nexus, except that defining a standardized
sleep-map should wait until its necessity is demonstrated).
+IX - Specifying dma bus information
+
+Some devices may have DMA memory range shifted relatively to the beginning of
+RAM, or even placed outside of kernel RAM. For example, the Keystone 2 SoC
+worked in LPAE mode with 4G memory has:
+- RAM range: [0x8 0000 0000, 0x8 FFFF FFFF]
+- DMA range: [ 0x8000 0000, 0xFFFF FFFF]
+and DMA range is aliased into first 2G of RAM in HW.
+
+In such cases, DMA addresses translation should be performed between CPU phys
+and DMA addresses. The "dma-ranges" property is intended to be used
+for describing the configuration of such system in DT.
+
+In addition, each DMA master device on the DMA bus may or may not support
+coherent DMA operations. The "dma-coherent" property is intended to be used
+for identifying devices supported coherent DMA operations in DT.
+
+* DMA Bus master
+Optional property:
+- dma-ranges: <prop-encoded-array> encoded as arbitrary number of triplets of
+ (child-bus-address, parent-bus-address, length). Each triplet specified
+ describes a contiguous DMA address range.
+ The dma-ranges property is used to describe the direct memory access (DMA)
+ structure of a memory-mapped bus whose device tree parent can be accessed
+ from DMA operations originating from the bus. It provides a means of
+ defining a mapping or translation between the physical address space of
+ the bus and the physical address space of the parent of the bus.
+ (for more information see ePAPR specification)
+
+* DMA Bus child
+Optional property:
+- dma-ranges: <empty> value. if present - It means that DMA addresses
+ translation has to be enabled for this device.
+- dma-coherent: Present if dma operations are coherent
+
+Example:
+soc {
+ compatible = "ti,keystone","simple-bus";
+ ranges = <0x0 0x0 0x0 0xc0000000>;
+ dma-ranges = <0x80000000 0x8 0x00000000 0x80000000>;
+
+ [...]
+
+ usb: usb@2680000 {
+ compatible = "ti,keystone-dwc3";
+
+ [...]
+ dma-coherent;
+ };
+};
+
Appendix A - Sample SOC node for MPC8540
========================================
diff --git a/Documentation/devicetree/dynamic-resolution-notes.txt b/Documentation/devicetree/dynamic-resolution-notes.txt
new file mode 100644
index 000000000000..083d23262abe
--- /dev/null
+++ b/Documentation/devicetree/dynamic-resolution-notes.txt
@@ -0,0 +1,25 @@
+Device Tree Dynamic Resolver Notes
+----------------------------------
+
+This document describes the implementation of the in-kernel
+Device Tree resolver, residing in drivers/of/resolver.c and is a
+companion document to Documentation/devicetree/dt-object-internal.txt[1]
+
+How the resolver works
+----------------------
+
+The resolver is given as an input an arbitrary tree compiled with the
+proper dtc option and having a /plugin/ tag. This generates the
+appropriate __fixups__ & __local_fixups__ nodes as described in [1].
+
+In sequence the resolver works by the following steps:
+
+1. Get the maximum device tree phandle value from the live tree + 1.
+2. Adjust all the local phandles of the tree to resolve by that amount.
+3. Using the __local__fixups__ node information adjust all local references
+ by the same amount.
+4. For each property in the __fixups__ node locate the node it references
+ in the live tree. This is the label used to tag the node.
+5. Retrieve the phandle of the target of the fixup.
+6. For each fixup in the property locate the node:property:offset location
+ and replace it with the phandle value.
diff --git a/Documentation/devicetree/of_selftest.txt b/Documentation/devicetree/of_selftest.txt
index 3a2f54d07fc5..1e3d5c92b5e3 100644
--- a/Documentation/devicetree/of_selftest.txt
+++ b/Documentation/devicetree/of_selftest.txt
@@ -67,14 +67,14 @@ struct device_node {
...
};
-Figure 1, describes a generic structure of machine’s un-flattened device tree
+Figure 1, describes a generic structure of machine's un-flattened device tree
considering only child and sibling pointers. There exists another pointer,
*parent, that is used to traverse the tree in the reverse direction. So, at
a particular level the child node and all the sibling nodes will have a parent
-pointer pointing to a common node (e.g. child1, sibling2, sibling3, sibling4’s
+pointer pointing to a common node (e.g. child1, sibling2, sibling3, sibling4's
parent points to root node)
-root (‘/’)
+root ('/')
|
child1 -> sibling2 -> sibling3 -> sibling4 -> null
| | | |
@@ -113,8 +113,8 @@ via the following kernel symbols:
__dtb_testcases_begin - address marking the start of test data blob
__dtb_testcases_end - address marking the end of test data blob
-Secondly, it calls of_fdt_unflatten_device_tree() to unflatten the flattened
-blob. And finally, if the machine’s device tree (i.e live tree) is present,
+Secondly, it calls of_fdt_unflatten_tree() to unflatten the flattened
+blob. And finally, if the machine's device tree (i.e live tree) is present,
then it attaches the unflattened test data tree to the live tree, else it
attaches itself as a live device tree.
@@ -122,7 +122,7 @@ attach_node_and_children() uses of_attach_node() to attach the nodes into the
live tree as explained below. To explain the same, the test data tree described
in Figure 2 is attached to the live tree described in Figure 1.
-root (‘/’)
+root ('/')
|
testcase-data
|
@@ -138,8 +138,8 @@ root->testcase-data->test-child0->test-child01->test-sibling1->test-sibling2
Figure 2: Example test data tree to be attached to live tree.
-According to the scenario above, the live tree is already present so it isn’t
-required to attach the root(‘/’) node. All other nodes are attached by calling
+According to the scenario above, the live tree is already present so it isn't
+required to attach the root('/') node. All other nodes are attached by calling
of_attach_node() on each node.
In the function of_attach_node(), the new node is attached as the child of the
@@ -148,7 +148,7 @@ replaces the current child and turns it into its sibling. So, when the testcase
data node is attached to the live tree above (Figure 1), the final structure is
as shown in Figure 3.
-root (‘/’)
+root ('/')
|
testcase-data -> child1 -> sibling2 -> sibling3 -> sibling4 -> null
| | | | |
@@ -170,7 +170,7 @@ testcase-data -> child1 -> sibling2 -> sibling3 -> sibling4 -> null
null
-----------------------------------------------------------------------
-root (‘/’)
+root ('/')
|
testcase-data -> child1 -> sibling2 -> sibling3 -> sibling4 -> null
| | | | |
@@ -191,8 +191,8 @@ test-child0 the test-sibling1 is attached that pushes the child node
as mentioned above.
If a duplicate node is found (i.e. if a node with same full_name property is
-already present in the live tree), then the node isn’t attached rather its
-properties are updated to the live tree’s node by calling the function
+already present in the live tree), then the node isn't attached rather its
+properties are updated to the live tree's node by calling the function
update_node_properties().
@@ -205,7 +205,7 @@ whole tree). selftest_data_remove() calls detach_node_and_children() that uses
of_detach_node() to detach the nodes from the live device tree.
To detach a node, of_detach_node() first updates all_next linked list, by
-attaching the previous node’s allnext to current node’s allnext pointer. And
-then, it either updates the child pointer of given node’s parent to its
-sibling or attaches the previous sibling to the given node’s sibling, as
+attaching the previous node's allnext to current node's allnext pointer. And
+then, it either updates the child pointer of given node's parent to its
+sibling or attaches the previous sibling to the given node's sibling, as
appropriate. That is it :)

Privacy Policy