Merge tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux

Pull device tree updates from Grant Likely:
 "The branch contains the following device tree changes the v3.17 merge
  window:

  Group changes to the device tree.  In preparation for adding device
  tree overlay support, OF_DYNAMIC is reworked so that a set of device
  tree changes can be prepared and applied to the tree all at once.
  OF_RECONFIG notifiers see the most significant change here so that
  users always get a consistent view of the tree.  Notifiers generation
  is moved from before a change to after it, and notifiers for a group
  of changes are emitted after the entire block of changes have been
  applied

  Automatic console selection from DT.  Console drivers can now use
  of_console_check() to see if the device node is specified as a console
  device.  If so then it gets added as a preferred console.  UART
  devices get this support automatically when uart_add_one_port() is
  called.

  DT unit tests no longer depend on pre-loaded data in the device tree.
  Data is loaded dynamically at the start of unit tests, and then
  unloaded again when the tests have completed.

  Also contains a few bugfixes for reserved regions and early memory
  setup"

* tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux: (21 commits)
  of: Fixing OF Selftest build error
  drivers: of: add automated assignment of reserved regions to client devices
  of: Use proper types for checking memory overflow
  of: typo fix in __of_prop_dup()
  Adding selftest testdata dynamically into live tree
  of: Add todo tasklist for Devicetree
  of: Transactional DT support.
  of: Reorder device tree changes and notifiers
  of: Move dynamic node fixups out of powerpc and into common code
  of: Make sure attached nodes don't carry along extra children
  of: Make devicetree sysfs update functions consistent.
  of: Create unlocked versions of node and property add/remove functions
  OF: Utility helper functions for dynamic nodes
  of: Move CONFIG_OF_DYNAMIC code into a separate file
  of: rename of_aliases_mutex to just of_mutex
  of/platform: Fix of_platform_device_destroy iteration of devices
  of: Migrate of_find_node_by_name() users to for_each_node_by_name()
  tty: Update hypervisor tty drivers to use core stdout parsing code.
  arm/versatile: Add the uart as the stdout device.
  of: Enable console on serial ports specified by /chosen/stdout-path
  ...

2 files changed, 51 insertions, 0 deletions

diff --git a/Documentation/devicetree/changesets.txt b/Documentation/devicetree/changesets.txt
new file mode 100644
index 000000000000..935ba5acc34e
--- /dev/null
+++ b/Documentation/devicetree/changesets.txt
@@ -0,0 +1,40 @@
+A DT changeset is a method which allows one to apply changes
+in the live tree in such a way that either the full set of changes
+will be applied, or none of them will be. If an error occurs partway
+through applying the changeset, then the tree will be rolled back to the
+previous state. A changeset can also be removed after it has been
+applied.
+
+When a changeset is applied, all of the changes get applied to the tree
+at once before emitting OF_RECONFIG notifiers. This is so that the
+receiver sees a complete and consistent state of the tree when it
+receives the notifier.
+
+The sequence of a changeset is as follows.
+
+1. of_changeset_init() - initializes a changeset
+
+2. A number of DT tree change calls, of_changeset_attach_node(),
+of_changeset_detach_node(), of_changeset_add_property(),
+of_changeset_remove_property, of_changeset_update_property() to prepare
+a set of changes. No changes to the active tree are made at this point.
+All the change operations are recorded in the of_changeset 'entries'
+list.
+
+3. mutex_lock(of_mutex) - starts a changeset; The global of_mutex
+ensures there can only be one editor at a time.
+
+4. of_changeset_apply() - Apply the changes to the tree. Either the
+entire changeset will get applied, or if there is an error the tree will
+be restored to the previous state
+
+5. mutex_unlock(of_mutex) - All operations complete, release the mutex
+
+If a successfully applied changeset needs to be removed, it can be done
+with the following sequence.
+
+1. mutex_lock(of_mutex)
+
+2. of_changeset_revert()
+
+3. mutex_unlock(of_mutex)
diff --git a/Documentation/devicetree/todo.txt b/Documentation/devicetree/todo.txt
new file mode 100644
index 000000000000..c3cf0659bd19
--- /dev/null
+++ b/Documentation/devicetree/todo.txt
@@ -0,0 +1,11 @@
+Todo list for devicetree:
+
+=== General structure ===
+- Switch from custom lists to (h)list_head for nodes and properties structure
+- Remove of_allnodes list and iterate using list of child nodes alone
+
+=== CONFIG_OF_DYNAMIC ===
+- Switch to RCU for tree updates and get rid of global spinlock
+- Document node lifecycle for CONFIG_OF_DYNAMIC
+- Always set ->full_name at of_attach_node() time
+- pseries: Get rid of open-coded tree modification from arch/powerpc/platforms/pseries/dlpar.c