Commit Graph

33 Commits

Author SHA1 Message Date
Saravana Kannan 01bb86b380 driver core: Add fwnode_init()
There are multiple locations in the kernel where a struct fwnode_handle
is initialized. Add fwnode_init() so that we have one way of
initializing a fwnode_handle.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20201121020232.908850-8-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-09 19:10:20 +01:00
Andy Shevchenko 9dcbac8424 software node: Use software_node_unregister() when unregistering group of nodes
After the commit
  46d26819a5 ("software node: implement software_node_unregister()")
has been applied a new helper appears that may be utilised in other places.
For time being there is one such place, i.e. in
software_node_unregister_node_group() which will benefit of the clean up.

Use software_node_unregister() when unregistering group of nodes.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200622082108.25577-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-10 14:35:37 +02:00
Linus Torvalds f558b8364e Driver core patches for 5.8-rc1
Here is the set of driver core patches for 5.8-rc1.
 
 Not all that huge this release, just a number of small fixes and
 updates:
 	- software node fixes
 	- kobject now sends KOBJ_REMOVE when it is removed from sysfs,
 	  not when it is removed from memory (which could come much
 	  later)
 	- device link additions and fixes based on testing on more
 	  devices
 	- firmware core cleanups
 	- other minor changes, full details in the shortlog
 
 All have been in linux-next for a while with no reported issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the set of driver core patches for 5.8-rc1.

  Not all that huge this release, just a number of small fixes and
  updates:

   - software node fixes

   - kobject now sends KOBJ_REMOVE when it is removed from sysfs, not
     when it is removed from memory (which could come much later)

   - device link additions and fixes based on testing on more devices

   - firmware core cleanups

   - other minor changes, full details in the shortlog

  All have been in linux-next for a while with no reported issues"

* tag 'driver-core-5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (23 commits)
  driver core: Update device link status correctly for SYNC_STATE_ONLY links
  firmware_loader: change enum fw_opt to u32
  software node: implement software_node_unregister()
  kobject: send KOBJ_REMOVE uevent when the object is removed from sysfs
  driver core: Remove unnecessary is_fwnode_dev variable in device_add()
  drivers property: When no children in primary, try secondary
  driver core: platform: Fix spelling errors in platform.c
  driver core: Remove check in driver_deferred_probe_force_trigger()
  of: platform: Batch fwnode parsing when adding all top level devices
  driver core: fw_devlink: Add support for batching fwnode parsing
  driver core: Look for waiting consumers only for a fwnode's primary device
  driver core: Move code to the right part of the file
  Revert "Revert "driver core: Set fw_devlink to "permissive" behavior by default""
  drivers: base: Fix NULL pointer exception in __platform_driver_probe() if a driver developer is foolish
  firmware_loader: move fw_fallback_config to a private kernel symbol namespace
  driver core: Add missing '\n' in log messages
  driver/base/soc: Use kobj_to_dev() API
  Add documentation on meaning of -EPROBE_DEFER
  driver core: platform: remove redundant assignment to variable ret
  debugfs: Use the correct style for SPDX License Identifier
  ...
2020-06-07 10:53:36 -07:00
Greg Kroah-Hartman 46d26819a5 software node: implement software_node_unregister()
Sometimes it is better to unregister individual nodes instead of trying
to do them all at once with software_node_unregister_nodes(), so create
software_node_unregister() so that you can unregister them one at a
time.

This is especially important when creating nodes in a hierarchy, with
parent -> children representations.  Children always need to be removed
before a parent is, as the swnode logic assumes this is going to be the
case.

Fix up the lib/test_printf.c fwnode_pointer() test which to use this new
function as it had the problem of tearing things down in the backwards
order.

Fixes: f1ce39df50 ("lib/test_printf: Add tests for %pfw printk modifier")
Cc: stable <stable@vger.kernel.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reported-by: kernel test robot <rong.a.chen@intel.com>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Petr Mladek <pmladek@suse.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20200524153041.2361-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27 00:13:32 +02:00
Andy Shevchenko 02094d5487 software node: Allow register and unregister software node groups
Sometimes it's more convenient to register a set of individual software nodes
grouped together. Add couple of functions for that.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Rafael J. Wysocki <rjw@rjwysocki.net>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
2020-04-20 14:41:56 +03:00
Brendan Higgins 7589238a8c Revert "software node: Simplify software_node_release() function"
This reverts commit 3df85a1ae5.

The reverted commit says "It's possible to release the node ID
immediately when fwnode_remove_software_node() is called, no need to
wait for software_node_release() with that." However, releasing the node
ID before waiting for software_node_release() to be called causes the
node ID to be released before the kobject and the underlying sysfs
entry; this means there is a period of time where a sysfs entry exists
that is associated with an unallocated node ID.

Once consequence of this is that there is a race condition where it is
possible to call fwnode_create_software_node() with no parent node
specified (NULL) and have it fail with -EEXIST because the node ID that
was assigned is still associated with a stale sysfs entry that hasn't
been cleaned up yet.

Although it is difficult to reproduce this race condition under normal
conditions, it can be deterministically reproduced with the following
minconfig on UML:

CONFIG_KUNIT_DRIVER_PE_TEST=y
CONFIG_DEBUG_KERNEL=y
CONFIG_DEBUG_OBJECTS=y
CONFIG_DEBUG_OBJECTS_TIMERS=y
CONFIG_DEBUG_KOBJECT_RELEASE=y
CONFIG_KUNIT=y

Running the tests with this configuration causes the following failure:

<snip>
kobject: 'node0' ((____ptrval____)): kobject_release, parent (____ptrval____) (delayed 400)
	ok 1 - pe_test_uints
sysfs: cannot create duplicate filename '/kernel/software_nodes/node0'
CPU: 0 PID: 28 Comm: kunit_try_catch Not tainted 5.6.0-rc3-next-20200227 #14
<snip>
kobject_add_internal failed for node0 with -EEXIST, don't try to register things with the same name in the same directory.
kobject: 'node0' ((____ptrval____)): kobject_release, parent (____ptrval____) (delayed 100)
	# pe_test_uint_arrays: ASSERTION FAILED at drivers/base/test/property-entry-test.c:123
	Expected node is not error, but is: -17
	not ok 2 - pe_test_uint_arrays
<snip>

Reported-by: Heidi Fahim <heidifahim@google.com>
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: 5.3+ <stable@vger.kernel.org> # 5.3+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-03-04 22:31:44 +01:00
Dmitry Torokhov e933bedd45 software node: remove separate handling of references
Now that all users of references have moved to reference properties,
we can remove separate handling of references.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-12-03 11:46:20 +01:00
Dmitry Torokhov e64b674bc9 software node: implement reference properties
It is possible to store references to software nodes in the same fashion as
other static properties, so that users do not need to define separate
structures:

static const struct software_node gpio_bank_b_node = {
	.name = "B",
};

static const struct property_entry simone_key_enter_props[] = {
	PROPERTY_ENTRY_U32("linux,code", KEY_ENTER),
	PROPERTY_ENTRY_STRING("label", "enter"),
	PROPERTY_ENTRY_REF("gpios", &gpio_bank_b_node, 123, GPIO_ACTIVE_LOW),
	{ }
};

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-12-03 11:46:20 +01:00
Dmitry Torokhov 996b0830f9 software node: allow embedding of small arrays into property_entry
We should not conflate whether a property data is an array or a single
value with where it is stored (embedded into property_entry structure or
out-of-line). All single-value properties are in effect 1-element
arrays, and we can figure the amount of data stored in a property by
examining its length and the data type. And arrays can be as easily
stored in property entry instances as single values are, provided that
we have enough space (we have up to 8 bytes). We can embed:

 - up to 8 bytes from U8 arrays
 - up to 4 words
 - up to 2 double words
 - one U64 value
 - one (on 64 bit architectures) or 2 (on 32 bit) strings.

This change also has an effect of switching properties with small amount
of data to embed it instead of keeping it separate when copying such
properties.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-12-03 11:46:19 +01:00
Dmitry Torokhov e6bff4665c software node: replace is_array with is_inline
We do not need a special flag to know if we are dealing with an
array, as we can get that data from ratio between element length and
the data size, but we do need a flag to know whether or not the data
is stored directly inside property_entry.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
[ rjw: Subject & changelog, struct property_entry kerneldoc ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-12-03 11:46:19 +01:00
Dmitry Torokhov 1afc14032e software node: simplify property_entry_read_string_array()
There is no need to treat string arrays and single strings separately, we can go
exclusively by the element length in relation to data type size.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-11-05 23:18:10 +01:00
Dmitry Torokhov 5236f5fe23 software node: remove property_entry_read_uNN_array functions
There is absolutely no reason to have them as we can handle it all nicely in
property_entry_read_int_array().

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-11-05 23:18:10 +01:00
Dmitry Torokhov 1f74d70ff2 software node: get rid of property_set_pointer()
Instead of explicitly setting values of integer types when copying
property entries lets just copy entire value union when processing
non-array values.

For value arrays we no longer use union of pointers, but rather a single
void pointer, which allows us to remove property_set_pointer().

In property_get_pointer() we do not need to handle each data type
separately, we can simply return either the pointer or pointer to values
union.

We are not losing anything from removing typed pointer union because the
upper layers do their accesses through void pointers anyway, and we
trust the "type" of the property when interpret the data. We rely on
users of property entries on using PROPERTY_ENTRY_XXX() macros to
properly initialize entries instead of poking in the instances directly.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-11-05 23:18:10 +01:00
Dmitry Torokhov 75dd63c968 software node: clean up property_copy_string_array()
Because property_copy_string_array() stores the newly allocated pointer in the
destination property, we have an awkward code in property_entry_copy_data()
where we fetch the new pointer from dst.

Let's change property_copy_string_array() to return pointer and rely on the
common path in property_entry_copy_data() to store it in destination structure.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-11-05 23:18:10 +01:00
Sakari Ailus e7e242bccb device property: Add a function to obtain a node's prefix
The prefix is used for printing purpose before a node, and it also works
as a separator between two nodes.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Rob Herring <robh@kernel.org> (for OF)
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-10-11 11:26:55 +02:00
Sakari Ailus bc0500c1e4 device property: Add fwnode_get_name for returning the name of a node
The fwnode framework did not have means to obtain the name of a node. Add
that now, in form of the fwnode_get_name() function and a corresponding
get_name fwnode op. OF and ACPI support is included.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Rob Herring <robh@kernel.org> (for OF)
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-10-11 11:26:55 +02:00
Sakari Ailus 56c9aa0794 software node: Make argument to to_software_node const
to_software_node() does not need to modify the fwnode_handle it operates
on; therefore make it const. This allows passing a const fwnode_handle to
to_software_node().

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-10-11 11:26:55 +02:00
Sakari Ailus 51c100a651 software node: Get reference to parent swnode in get_parent op
The software_node_get_parent() returned a pointer to the parent swnode,
but did not take a reference to it, leading the caller to put a reference
that was not taken. Take that reference now.

Fixes: 59abd83672 ("drivers: base: Introducing software nodes to the firmware node framework")
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-10-11 11:26:55 +02:00
Heikki Krogerus 016049a816 software node: Initialize the return value in software_node_find_by_name()
The software node is searched from a list that may be empty
when the function is called. This makes sure that the
function returns NULL if the list is empty.

Fixes: 1666faedb5 ("software node: Add software_node_find_by_name()")
Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-09-11 19:10:12 +02:00
Heikki Krogerus 616368735e software node: Initialize the return value in software_node_to_swnode()
The software node is searched from a list that may be empty
when the function is called. This makes sure that the
function returns NULL even if the list is empty.

Fixes: 80488a6b1d ("software node: Add support for static node descriptors")
Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-09-04 23:03:19 +02:00
Heikki Krogerus 1666faedb5 software node: Add software_node_find_by_name()
Function that searches software nodes by node name.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-08-26 11:35:13 +02:00
Heikki Krogerus b06184acf7 software node: Add software_node_get_reference_args()
This makes it possible to support drivers that use
fwnode_property_get_reference_args() function.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-06-03 10:55:38 +02:00
Heikki Krogerus c959d0c231 software node: Use kobject name when finding child nodes by name
Using the kobject name of the node instead of a device
property "name" in software_node_get_named_child_node().

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-06-03 10:55:38 +02:00
Heikki Krogerus 80488a6b1d software node: Add support for static node descriptors
Until now the software nodes could only be created
dynamically with fwnode_create_software_node() function.
This introduces struct software_node data structure, which
makes it possible to describe the software nodes also
statically.

The statically described software nodes can be registered
with a new function fwnode_register_software_node(). This
also adds a helper fwnode_register_software_nodes()
which makes it possible to register an array of struct
software_nodes, i.e. multiple nodes at the same time.

There is no difference between statically described and
dynamically allocated software nodes. Even the registration
does not differ, except that during node creation the device
properties are only copied if the node is created
dynamically. With statically described nodes, the property
entries in the descriptor (struct software_node) are
assigned directly to the new software node that is being
created without any copies.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-06-03 10:55:38 +02:00
Heikki Krogerus 3df85a1ae5 software node: Simplify software_node_release() function
It's possible to release the node ID immediately when
fwnode_remove_software_node() is called, no need to wait for
software_node_release() with that.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-06-03 10:55:38 +02:00
Heikki Krogerus a79969868a software node: Allow node creation without properties
Software nodes are not forced to have device properties.
Adding check to property_entries_dup() to make it possible
to create software nodes that don't have any properties.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-06-03 10:55:38 +02:00
YueHaibing 0e3edd9444 drivers: base: swnode: Make two functions static
Fix sparse warning:

drivers/base/swnode.c:475:22: warning: symbol 'software_node_get_parent' was not declared. Should it be static?
drivers/base/swnode.c:484:22: warning: symbol 'software_node_get_next_child' was not declared. Should it be static?

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-03-19 16:37:56 +01:00
Heikki Krogerus 344798206f software node: Implement get_named_child_node fwnode callback
This makes it possible to support drivers that use
fwnode_get_named_child_node() and device_get_named_child_node()
functions.

The node name is for now taken from a device property named
"name". That mimics the old style of naming of the nodes in
devicetree (though with modern flattened DT, the name is
matched against the actual node-name, it used to be done
with a property "name"). In Open Firmware DT the "name"
property is also still being used.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-02-14 11:33:15 +01:00
Colin Ian King f4747b9c68 drivers: base: swnode: check if swnode is NULL before dereferencing it
The to_software_mode() macro can potentially return NULL, so also add
a NULL check on swnode before dereferencing it to avoid any NULL
pointer dereferences.

Detected by CoverityScan, CID#1476052 ("Explicit null dereferenced")

Fixes: 59abd83672 (drivers: base: Introducing software nodes to the firmware node framework)
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-12-26 10:50:36 +01:00
Colin Ian King 1d8f062ebc drivers: base: swnode: check if pointer p is NULL before dereferencing it
The pointer p can be potentially NULL as macro to_software_node can
return NULL.

Add null check on p before dereferencing it to avoid any NULL pointer
dereferences.

Detected by CoverityScan, CID#1476039 ("Explicit null dereferenced")

Fixes: 59abd83672 (drivers: base: Introducing software nodes to the firmware node framework)
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-12-26 10:48:01 +01:00
Colin Ian King d84f18d667 drivers: base: swnode: remove need for a temporary string for the node name
Currently the node name is being formatting into a temporary string
node_name, however, kobject_init_and_add allows one to format up
a node name, so use that instead. This removes the need for the
node_name string and also cleans up the following warning:

Fixes clang warning:
warning: format string is not a string literal (potentially
insecure) [-Wformat-security]

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-12-11 12:18:15 +01:00
Heikki Krogerus ed1cdf31f9 device property: Move device_add_properties() to swnode.c
Concentrating struct property_entry processing to
drivers/base/swnode.c

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-11-26 18:19:11 +01:00
Heikki Krogerus 59abd83672 drivers: base: Introducing software nodes to the firmware node framework
Software node is a new struct fwnode_handle type that can be
used to describe devices in kernel (software). It is meant
to complement fwnodes representing real firmware nodes when
they are incomplete (for example missing device properties)
and to supply the primary fwnode when the firmware lacks
hardware description for a device completely.

The software node type is really meant to replace the
currently used "property_set" struct fwnode_handle type. The
handling of struct property_set is glued to the generic
device property handling code, and it is not possible to
create a struct property_set independently from the device
that it is bind to. struct property_set is only created when
device properties are added to already initialized struct
device, and control of it is only possible from the generic
property handling code.

Software nodes are instead designed to be created
independently from the device entries (struct device). It
makes them much more flexible, as then the device meant to
be bind to the node can be created at a later time, and from
another location. It is also possible to bind multiple
devices to a single software node if needed.

The software node implementation also includes support for
node hierarchy, which was the main motivation for this
commit. The node hierarchy was something that was requested
for the struct property_set, but it did not seem reasonable
to try to extend the property_set support for that purpose.
struct property_set was really meant only for device
property handling like the name suggests.

Support for struct property_set is not yet removed in this
commit, but it will be in the following one.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-11-26 18:19:11 +01:00