Currently platforms/drivers needing to get the machine model name are
replicating the same snippet of code. In some case, the OF reference
counting is either missing or incorrect.

This patch adds support to read the machine model name either using
the "model" or the "compatible" property in the device tree root node
to the core OF/DT code.

This can be used to remove all the duplicate code snippets doing exactly
same thing later.

Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Signed-off-by: NRob Herring <robh@kernel.org>

If a device tree specifies a preferred device for kernel console output
via the stdout-path or linux,stdout-path chosen node properties or the
stdout alias then the kernel ought to honor it & output the kernel
console to that device.  As it stands, this isn't the case.  Whilst we
parse the stdout-path properties & set an of_stdout variable from
of_alias_scan(), and use that from of_console_check() to determine
whether to add a console device as a preferred console whilst
registering it, we also prefer the first registered console if no other
has been selected at the time of its registration.

This means that if a console other than the one the device tree selects
via stdout-path is registered first, we will switch to using it & when
the stdout-path console is later registered the call to
add_preferred_console() via of_console_check() is too late to do
anything useful.  In practice this seems to mean that we switch to the
dummy console device fairly early & see no further console output:

    Console: colour dummy device 80x25
    console [tty0] enabled
    bootconsole [ns16550a0] disabled

Fix this by not automatically preferring the first registered console if
one is specified by the device tree.  This allows consoles to be
registered but not enabled, and once the driver for the console selected
by stdout-path calls of_console_check() the driver will be added to the
list of preferred consoles before any other console has been enabled.
When that console is then registered via register_console() it will be
enabled as expected.

Link: http://lkml.kernel.org/r/20160809151937.26118-1-paul.burton@imgtec.comSigned-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Ivan Delalande <colona@arista.com>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Jan Kara <jack@suse.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Joe Perches <joe@perches.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a new set of array reading functions that take a minimum and
maximum size limit and will fail if the property size is not within
the size limits. This makes it more convenient for drivers that
use variable-size DT arrays which must be bounded at both ends -
data must be at least N entries but must not overflow the array
it is being copied into. It is also more efficient than making this
functionality out of existing public functions and avoids duplication.

The existing array functions have been left in the API, since there
are a very large number of clients of those functions and their
existing functionality is still useful. This avoids turning a small
API improvement into a major kernel rework.

The old functions have been turned into mininmal static inlines calling
the new functions. The old functions had no upper limit on the actual
size of the dts entry, to preserve this functionality rather than keeping
two near-identical implementations, if the new function is called with
max=0 there is no limit on the size of the dts entry but only the min
number of elements are read.
Signed-off-by: NRichard Fitzgerald <rf@opensource.wolfsonmicro.com>
Signed-off-by: NRob Herring <robh@kernel.org>

In preparation for adding variable-length array reads, change
of_find_property_value_of_size so that it takes an optional
maximum length. If the maximum is passed as 0, the behaviour is
unchanged and it will return a property if it's >= the requested
minimum length. If maximum is non-zero it will only return a
property whose length is min <= l <= max.
Signed-off-by: NRichard Fitzgerald <rf@opensource.wolfsonmicro.com>
Signed-off-by: NRob Herring <robh@kernel.org>

The called of_graph_get_next_endpoint() already decrements the refcount
of the prev node, so it is wrong to do it again in the calling function.

Use the for_each_endpoint_of_node() helper to interate through the
endpoint OF nodes, which already does the right thing and simplifies
the code a bit.

Fixes: 8ccd0d0c
(of: add helper for getting endpoint node of specific identifiers)
Cc: stable@vger.kernel.org
Reported-by: NDavid Jander <david@protonic.nl>
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Acked-by: NPhilipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: NRob Herring <robh@kernel.org>

The of_node_put() function tests whether its argument is NULL
and then returns immediately.
Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.
Signed-off-by: NMarkus Elfring <elfring@users.sourceforge.net>
Signed-off-by: NRob Herring <robh@kernel.org>

This provides an equivalent of of_fdt_match() for non-flat trees.

This is more practical than matching an array of of_device_id structs
when converting a bunch of existing users of of_fdt_match().
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Clean-up all the DT printk functions to use common pr_fmt prefix.

Some print statements such as kmalloc errors were redundant, so just
drop those.

Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Reviewed-by: NFrank Rowand <frank.rowand@am.sony.com>
Signed-off-by: NRob Herring <robh@kernel.org>

Fix a memory leak resulting from memory allocation in safe_name().
This patch fixes all call sites of safe_name().

Mathieu Malaterre reported the memory leak on boot:

On my PowerMac device-tree would generate a duplicate name:

[    0.023043] device-tree: Duplicate name in PowerPC,G4@0, renamed to "l2-cache#1"

in this case a newly allocated name is generated by `safe_name`. However
in this case it is never deallocated.

The bug was found using kmemleak reported as:

unreferenced object 0xdf532e60 (size 32):
  comm "swapper", pid 1, jiffies 4294892300 (age 1993.532s)
  hex dump (first 32 bytes):
    6c 32 2d 63 61 63 68 65 23 31 00 dd e4 dd 1e c2  l2-cache#1......
    ec d4 ba ce 04 ec cc de 8e 85 e9 ca c4 ec cc 9e  ................
  backtrace:
    [<c02d3350>] kvasprintf+0x64/0xc8
    [<c02d3400>] kasprintf+0x4c/0x5c
    [<c0453814>] safe_name.isra.1+0x80/0xc4
    [<c04545d8>] __of_attach_node_sysfs+0x6c/0x11c
    [<c075f21c>] of_core_init+0x8c/0xf8
    [<c0729594>] kernel_init_freeable+0xd4/0x208
    [<c00047e8>] kernel_init+0x24/0x11c
    [<c00158ec>] ret_from_kernel_thread+0x5c/0x64

Link: https://bugzilla.kernel.org/show_bug.cgi?id=120331Signed-off-by: NFrank Rowand <frank.rowand@am.sony.com>
Reported-by: mathieu.malaterre@gmail.com
Tested-by: NMathieu Malaterre <mathieu.malaterre@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: NRob Herring <robh@kernel.org>

The validity of the property input argument to of_remove_property() is
never checked within the function and thus it is possible to pass a null
value. It happens that this will be picked up in __of_remove_property()
as no matching property of the device node will be found and thus an
error will be returned, however once again there is no explicit check
for a null value. By the time this is detected 2 locks have already been
acquired which is completely unnecessary if the property to remove is
null.

Add an explicit check in the function of_remove_property() for a null
property value and return -ENODEV in this case, this is consistent with
what the previous return value would have been when the null value was
not detected and passed to __of_remove_property().

By moving an explicit check for the property paramenter into the
of_remove_property() function, this will remove the need to perform this
check in calling code before invocation of the of_remove_property()
function.
Signed-off-by: NSuraj Jitindar Singh <sjitindarsingh@gmail.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

This function increments refcount.  This is worth noting.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NFrank Rowand <frank.rowand@am.sony.com>
Signed-off-by: NRob Herring <robh@kernel.org>

This helper function can be used to copy the arguments of a
phandle to an array.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>
Signed-off-by: NRob Herring <robh@kernel.org>

With this macro any user can easily iterate over a list of
phandles. The patch also converts __of_parse_phandle_with_args()
to make use of the macro.

The of_count_phandle_with_args() function is not converted,
because the macro hides the return value of of_phandle_iterator_init(),
which is needed in there.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>
Signed-off-by: NRob Herring <robh@kernel.org>

The index = -1 case in __of_parse_phandle_with_args() is
used to just return the number of phandles. That special
case needs extra handling, so move it to the place where it
is needed: of_count_phandle_with_args().

This allows to further simplify __of_parse_phandle_with_args()
later on.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>
Signed-off-by: NRob Herring <robh@kernel.org>

Move the code to walk over the phandles out of the loop in
__of_parse_phandle_with_args() to a separate function that
just works with the iterator handle: of_phandle_iterator_next().
Signed-off-by: NJoerg Roedel <jroedel@suse.de>
Signed-off-by: NRob Herring <robh@kernel.org>

This struct carrys all necessary information to iterate over
a list of phandles and extract the arguments. Add an
init-function for the iterator and make use of it in
__of_parse_phandle_with_args().
Signed-off-by: NJoerg Roedel <jroedel@suse.de>
Signed-off-by: NRob Herring <robh@kernel.org>

The of_property_{read,count,match}_string* family of functions never
modify the struct device_node pointer that is passed in, so there is no
reason for it to be non-const. Equivalent functions for all other types
already take a 'const struct device_node *np'.
Signed-off-by: NDavid Rivshin <drivshin@allworx.com>
Signed-off-by: NRob Herring <robh@kernel.org>

This commit does not change the function behavior.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NRob Herring <robh@kernel.org>

This symbol came via exynos-next, but modular builds are broken
so just fix it up now.
Signed-off-by: NDave Airlie <airlied@redhat.com>

When there are multiple ports or multiple endpoints in a port, they have to be
distinguished by the value of reg property. It is common. The drivers can get
the specific endpoint in the specific port via this function. Now the drivers
have to implement this code in themselves or have to force the order of dt nodes
to get the right node.
Signed-off-by: NHyungwon Hwang <human.hwang@samsung.com>
Acked-by: NRob Herring <robh+dt@kernel.org>
Signed-off-by: NInki Dae <inki.dae@samsung.com>

Node 0 might be offline as well as any other numa node,
in this case kernel cannot handle memory allocation and crashes.
Signed-off-by: NKonstantin Khlebnikov <khlebnikov@yandex-team.ru>
Fixes: 0c3f061c ("of: implement of_node_to_nid as a weak function")
Signed-off-by: NGrant Likely <grant.likely@linaro.org>

Commit 5590f319 ("drivers/core/of: Add symlink to device-tree from
devices with an OF node") adds the symlink `of_node` for each device
pointing to it's device tree node while creating/initialising it.

However the devicetree sysfs is created and setup in of_init which is
executed at core_initcall level. For all the devices created before
of_init, the following error is thrown:
	"Error -2(-ENOENT) creating of_node link"

Like many other components in driver model, initialize the sysfs support
for OF/devicetree from driver_init so that it's ready before any devices
are created.

Fixes: 5590f319 ("drivers/core/of: Add symlink to device-tree from
	devices with an OF node")
Suggested-by: NRob Herring <robh+dt@kernel.org>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Tested-by: NRobert Schwebel <r.schwebel@pengutronix.de>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 5590f319 ("drivers/core/of: Add symlink to device-tree from
devices with an OF node") adds the symlink `of_node` for each device
pointing to it's device tree node while creating/initialising it.

However the devicetree sysfs is created and setup in of_init which is
executed at core_initcall level. For all the devices created before
of_init, the following error is thrown:
	"Error -2(-ENOENT) creating of_node link"

Like many other components in driver model, initialize the sysfs support
for OF/devicetree from driver_init so that it's ready before any devices
are created.

Fixes: 5590f319 ("drivers/core/of: Add symlink to device-tree from
	devices with an OF node")
Suggested-by: NRob Herring <robh+dt@kernel.org>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Tested-by: NRobert Schwebel <r.schwebel@pengutronix.de>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add two new facts to of_get_next_child() documentation:

   * of_get_next_child() returns NULL when there is not next child

   * of_get_next_child() decrements the refcount of prev
Signed-off-by: NBaruch Siach <baruch@tkos.co.il>
Signed-off-by: NRob Herring <robh@kernel.org>

SoC peripherals can come in several different flavors:

 - little-endian: registers always need to be accessed in LE mode (so the
   kernel should perform a swap if the CPU is running BE)

 - big-endian: registers always need to be accessed in BE mode (so the
   kernel should perform a swap if the CPU is running LE)

 - native-endian: the bus will automatically swap accesses, so the kernel
   should never swap

Introduce a function that checks an OF device node to see whether it
contains a "big-endian" or "native-endian" property.  For the former case,
always return true.  For the latter case, return true iff the kernel was
built for BE (implying that the BE MMIO accessors do not perform a swap).
Otherwise return false, assuming LE registers.

LE registers are assumed by default because most existing drivers (libahci,
serial8250, usb) always use readl/writel in the absence of instructions
to the contrary, so that will be our fallback.
Signed-off-by: NKevin Cernekee <cernekee@gmail.com>
Reviewed-by: NPeter Hurley <peter@hurleysoftware.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NRob Herring <robh@kernel.org>

This reverts commit 2fa645cb.

The assumption that at least 1 preferred console will be registered
when the stdout-path property is set is invalid, which can result
in _no_ consoles.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NRob Herring <robh@kernel.org>

Commit 106937e8 ("of: fix handling of '/' in options for
of_find_node_by_path()") caused a regression in OF handling of
stdout-path. While it fixes some cases which have '/' after the ':', it
breaks cases where there is more than one '/' *before* the ':'.

For example, it breaks this boot string

  stdout-path = "/rdb/serial@f040ab00:115200";

So rather than doing sequentialized checks (first for '/', then for ':';
or vice versa), to get the correct behavior we need to check for the
first occurrence of either one of them.

It so happens that the handy strcspn() helper can do just that.

Fixes: 106937e8 ("of: fix handling of '/' in options for of_find_node_by_path()")
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Cc: stable@vger.kernel.org # 3.19
Acked-by: NLeif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: NRob Herring <robh@kernel.org>

I2C supports adding adapters using either a dynamic or fixed id. The
latter is provided by aliases in the DT case. To prevent id collisions
of those two types, install this function which gives us the highest
fixed id, so we can then let the dynamically created ones come after
this highest number.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Ensure proper handling of paths with appended options (after ':'),
where those options may contain a '/'.

Fixes: 7914a7c5 ("of: support passing console options with stdout-path")
Reported-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NLeif Lindholm <leif.lindholm@linaro.org>
Cc: <stable@vger.kernel.org> # 3.19
Signed-off-by: NRob Herring <robh@kernel.org>

Support for devicetree serial consoles via 'stdout-path' causes
bootconsoles to be disabled when the vt dummy console loads, since
there is no preferred console (the preferred console is not added
until the device is probed).

Ensure there is at least a preferred console, even if never matched.

Requires: "console: Fix console name size mismatch"
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NRob Herring <robh@kernel.org>

This patch adds a function to get a port device tree node by port id,
or reg property value.
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>

Decrementing the reference count of the previous endpoint node allows to
use the of_graph_get_next_endpoint function in a for_each_... style macro.
All current users of this function that pass a non-NULL prev parameter
(that is, soc_camera and imx-drm) are changed to not decrement the passed
prev argument's refcount themselves.
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>
Acked-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>
Acked-by: NMathieu Poirier <mathieu.poirier@linaro.org>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: NTomi Valkeinen <tomi.valkeinen@ti.com>

Make of_property_read_u64_array() available for modules as well. This was
missing from the patch which originally added the function.
Signed-off-by: NSakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: NRob Herring <robh@kernel.org>

Support specifying console options (like with console=ttyXN,<options>)
by appending them to the stdout-path property after a separating ':'.

Example:
        stdout-path = "uart0:115200";
Signed-off-by: NLeif Lindholm <leif.lindholm@linaro.org>
[grant.likely: minor rework to shorten the diffstat]
Signed-off-by: NGrant Likely <grant.likely@linaro.org>

Update of_find_node_by_path():
1) Rename function to of_find_node_opts_by_path(), adding an optional
   pointer argument. Provide a static inline wrapper version of
   of_find_node_by_path() which calls the new function with NULL as
   the optional argument.
2) Ignore any part of the path beyond and including the ':' separator.
3) Set the new provided pointer argument to the beginning of the string
   following the ':' separator.
4: Add tests.
Signed-off-by: NLeif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: NGrant Likely <grant.likely@linaro.org>

It referenced of_property_read_string_util whereas the function name
is of_property_read_string_helper.

Introduced in a87fa1d8 (of: Fix
overflow bug in string property parsing functions). Found out when
reviewing the stable 3.12 queue.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NGrant Likely <grant.likely@linaro.org>

This function can only return true or false; using a bool makes it more
obvious to the reader.
Signed-off-by: NKevin Cernekee <cernekee@gmail.com>
Signed-off-by: NGrant Likely <grant.likely@linaro.org>

This function passes back a value from __of_device_is_compatible(), which
returns a score in the range 0..11, not a bool.
Signed-off-by: NKevin Cernekee <cernekee@gmail.com>
Signed-off-by: NGrant Likely <grant.likely@linaro.org>

Add a uniform interface by which device drivers can request device
properties from the platform firmware by providing a property name
and the corresponding data type.  The purpose of it is to help to
write portable code that won't depend on any particular platform
firmware interface.

The following general helper functions are added:

device_property_present()
device_property_read_u8()
device_property_read_u16()
device_property_read_u32()
device_property_read_u64()
device_property_read_string()
device_property_read_u8_array()
device_property_read_u16_array()
device_property_read_u32_array()
device_property_read_u64_array()
device_property_read_string_array()

The first one allows the caller to check if the given property is
present.  The next 5 of them allow single-valued properties of
various types to be retrieved in a uniform way.  The remaining 5 are
for reading properties with multiple values (arrays of either numbers
or strings).

The interface covers both ACPI and Device Trees.

This change set includes material from Mika Westerberg and Aaron Lu.
Signed-off-by: NAaron Lu <aaron.lu@intel.com>
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NGrant Likely <grant.likely@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGrant Likely <grant.likely@linaro.org>