Before commit e42ee610 ("of: Let of_for_each_phandle fallback to
non-negative cell_count") the iterator functions calling
of_for_each_phandle assumed a cell count of 0 if cells_name was NULL.
This corner case was missed when implementing the fallback logic in
e42ee610 and resulted in an endless loop.

Restore the old behaviour of of_count_phandle_with_args() and
of_parse_phandle_with_args() and add a check to
of_phandle_iterator_init() to prevent a similar failure as a safety
precaution. of_parse_phandle_with_args_map() doesn't need a similar fix
as cells_name isn't NULL there.

Affected drivers are:
 - drivers/base/power/domain.c
 - drivers/base/power/domain.c
 - drivers/clk/ti/clk-dra7-atl.c
 - drivers/hwmon/ibmpowernv.c
 - drivers/i2c/muxes/i2c-demux-pinctrl.c
 - drivers/iommu/mtk_iommu.c
 - drivers/net/ethernet/freescale/fman/mac.c
 - drivers/opp/of.c
 - drivers/perf/arm_dsu_pmu.c
 - drivers/regulator/of_regulator.c
 - drivers/remoteproc/imx_rproc.c
 - drivers/soc/rockchip/pm_domains.c
 - sound/soc/fsl/imx-audmix.c
 - sound/soc/fsl/imx-audmix.c
 - sound/soc/meson/axg-card.c
 - sound/soc/samsung/tm2_wm5110.c
 - sound/soc/samsung/tm2_wm5110.c

Thanks to Geert Uytterhoeven for reporting the issue, Peter Rosin for
helping pinpoint the actual problem and the testers for confirming this
fix.

Fixes: e42ee610 ("of: Let of_for_each_phandle fallback to non-negative cell_count")
Tested-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Tested-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NRob Herring <robh@kernel.org>

Referencing device tree nodes from a property allows to pass arguments.
This is for example used for referencing gpios. This looks as follows:

	gpio_ctrl: gpio-controller {
		#gpio-cells = <2>
		...
	}

	someothernode {
		gpios = <&gpio_ctrl 5 0 &gpio_ctrl 3 0>;
		...
	}

To know the number of arguments this must be either fixed, or the
referenced node is checked for a $cells_name (here: "#gpio-cells")
property and with this information the start of the second reference can
be determined.

Currently regulators are referenced with no additional arguments. To
allow some optional arguments without having to change all referenced
nodes this change introduces a way to specify a default cell_count. So
when a phandle is parsed we check for the $cells_name property and use
it as before if present. If it is not present we fall back to
cells_count if non-negative and only fail if cells_count is smaller than
zero.
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NRob Herring <robh@kernel.org>

In PCI root complex nodes, the iommu-map property describes the IOMMU that
translates each endpoint. On some platforms, the IOMMU itself is presented
as a PCI endpoint (e.g. AMD IOMMU and virtio-iommu). This isn't supported
by the current OF driver, which expects all endpoints to have an IOMMU.
Allow the iommu-map property to have gaps.

Relaxing of_map_rid() also allows the msi-map property to have gaps, which
is invalid since MSIs always reach an MSI controller. In that case
pci_msi_setup_msi_irqs() will return an error when attempting to find the
device's MSI domain.
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NJean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

Understanding why of_phandle_iterator_next() returns an error can
sometimes be hard to decipher based solely on the error message, a
typical error example is that #foo-cells = <X> and the phandle property
used has a smaller number of cells specified, e.g.:

	#thermal-sensor-cells = <1>;
	phandle = <&scmi_sensor>

instead of:

	phandle <&scmi_sensor 0>;

Instead, make it clear what the expectations are towards debugging
incorrect Device Tree faster:

OF: /thermal-zones/scmi-thermal: #thermal-sensor-cells = 1, found 0 instead
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NRob Herring <robh@kernel.org>

Non-overlay dynamic devicetree node removal may leave the node in
the phandle cache.  Subsequent calls to of_find_node_by_phandle()
will incorrectly find the stale entry.  Remove the node from the
cache.

Add paranoia checks in of_find_node_by_phandle() as a second level
of defense (do not return cached node if detached, do not add node
to cache if detached).

Fixes: 0b3ce78e ("of: cache phandle nodes to reduce cost of of_find_node_by_phandle()")
Reported-by: NMichael Bringmann <mwb@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # v4.17+
Signed-off-by: NFrank Rowand <frank.rowand@sony.com>
Signed-off-by: NRob Herring <robh@kernel.org>

The phandle cache contains struct device_node pointers.  The refcount
of the pointers was not incremented while in the cache, allowing use
after free error after kfree() of the node.  Add the proper increment
and decrement of the use count.

Fixes: 0b3ce78e ("of: cache phandle nodes to reduce cost of of_find_node_by_phandle()")
Cc: stable@vger.kernel.org # v4.17+
Signed-off-by: NFrank Rowand <frank.rowand@sony.com>
Signed-off-by: NRob Herring <robh@kernel.org>

Convert string compares of DT node names to use of_node_name_eq helper
instead. This removes direct access to the node name pointer.

Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Cc: devicetree@vger.kernel.org
Signed-off-by: NRob Herring <robh@kernel.org>

Remove directly accessing device_node.type pointer and use the accessors
instead. This will eventually allow removing the type pointer.

Cc: Frank Rowand <frowand.list@gmail.com>
Cc: devicetree@vger.kernel.org
Signed-off-by: NRob Herring <robh@kernel.org>

In most cases, nodes with 'status = "disabled";' are treated as if the
node is not present though it is a common bug to forget to check that.
However, cpu nodes are different in that "disabled" simply means offline
and the OS can bring the CPU core online. Commit f1f207e4 ("of: Add
cpu node iterator for_each_of_cpu_node()") followed the common behavior
of ignoring disabled cpu nodes. This breaks some powerpc systems (at
least NXP P50XX/e5500). Fix this by dropping the status check.

Fixes: 651d44f9 ("of: use for_each_of_cpu_node iterator")
Fixes: f1f207e4 ("of: Add cpu node iterator for_each_of_cpu_node()")
Reported-by: NChristian Zigotzky <chzigotzky@xenosoft.de>
Tested-by: NMichael Ellerman <mpe@ellerman.id.au>
Cc: Frank Rowand <frowand.list@gmail.com>
Signed-off-by: NRob Herring <robh@kernel.org>

Commit f42b0e18 ("of: add node name compare helper functions")
failed to add the module exports to of_node_name_eq() and
of_node_name_prefix(). Add them now.

Fixes: f42b0e18 ("of: add node name compare helper functions")
Signed-off-by: NRob Herring <robh@kernel.org>

Check compatible string first before setting up bit in bitmap to also
cover cases that allocated bitfield is not big enough.
Show warning about it but let driver to continue to work with allocated
bitfield to keep at least some devices (included console which
is commonly close to serial0) to work.

Fixes: b1078c35 ("of: base: Introduce of_alias_get_alias_list() to check alias IDs")
Fixes: ae1cca3f ("serial: uartps: Change uart ID port allocation")
Signed-off-by: NMichal Simek <michal.simek@xilinx.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix english spelling in of_alias_get_alias_list().
Reported-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Reported-by: NRandy Dunlap <rdunlap@infradead.org>
Fixes: b1078c35 ("of: base: Introduce of_alias_get_alias_list() to check alias IDs")
Signed-off-by: NMichal Simek <michal.simek@xilinx.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use the for_each_of_cpu_node iterator to iterate over cpu nodes. This
has the side effect of defaulting to iterating using "cpu" node names in
preference to the deprecated (for FDT) device_type == "cpu".

Cc: Frank Rowand <frowand.list@gmail.com>
Cc: devicetree@vger.kernel.org
Reviewed-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NRob Herring <robh@kernel.org>

For some single core ARM systems, the DTs can have a single cpu node
without a reg property and #address-cells == 0. This case is valid and
should match on cpu #0.

Cc: Frank Rowand <frowand.list@gmail.com>
Signed-off-by: NRob Herring <robh@kernel.org>

Iterating thru cpu nodes is a common pattern. Create a common iterator
which can find child nodes either by node name or device_type == cpu.
Using the former will allow for eventually dropping device_type
properties which are deprecated for FDT.

Cc: Frank Rowand <frowand.list@gmail.com>
Reviewed-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NRob Herring <robh@kernel.org>

iommu-map property is also used by devices with fsl-mc. This
patch moves the of_pci_map_rid to generic location, so that it
can be used by other busses too.

'of_pci_map_rid' is renamed here to 'of_map_rid' and there is no
functional change done in the API.
Signed-off-by: NNipun Gupta <nipun.gupta@nxp.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Reviewed-by: NRobin Murphy <robin.murphy@arm.com>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

The function travels the lookup table to record alias ids for the given
device match structures and alias stem.
This function will be used by serial drivers to check if requested alias
is allocated or free to use.
Signed-off-by: NMichal Simek <michal.simek@xilinx.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

With commit 0b3ce78e ("of: cache phandle nodes to reduce cost of
of_find_node_by_phandle()"), a G3 PowerMac fails to boot. The root cause
is the DT for this system has no phandle properties when booted with
BootX. of_populate_phandle_cache() does not handle the case of no
phandles correctly. The problem is roundup_pow_of_two() for 0 is
undefined. The implementation subtracts 1 underflowing and then things
are in the weeds.

Fixes: 0b3ce78e ("of: cache phandle nodes to reduce cost of of_find_node_by_phandle()")
Cc: stable@vger.kernel.org # 4.17+
Reported-by: NFinn Thain <fthain@telegraphics.com.au>
Tested-by: NStan Johnson <userm57@yahoo.com>
Reviewed-by: NFrank Rowand <frank.rowand@sony.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NRob Herring <robh@kernel.org>

Cache nodes under the cpu node(s) is PowerMac specific according to the
comment above, so make the code enforce that.
Signed-off-by: NRob Herring <robh@kernel.org>

In preparation to remove device_node.name pointer, add helper functions
for node name comparisons which are a common pattern throughout the kernel.

Cc: Frank Rowand <frowand.list@gmail.com>
Signed-off-by: NRob Herring <robh@kernel.org>

Add of_get_compatible_child() helper that can be used to lookup
compatible child nodes.

Several drivers currently use of_find_compatible_node() to lookup child
nodes while failing to notice that the of_find_ functions search the
entire tree depth-first (from a given start node) and therefore can
match unrelated nodes. The fact that these functions also drop a
reference to the node they start searching from (e.g. the parent node)
is typically also overlooked, something which can lead to use-after-free
bugs.
Signed-off-by: NJohan Hovold <johan@kernel.org>
Signed-off-by: NRob Herring <robh@kernel.org>

A comment in the review of the patch adding the phandle cache said that
the cache would have to be updated when modules are applied and removed.
This patch implements the cache updates.

Fixes: 0b3ce78e ("of: cache phandle nodes to reduce cost of of_find_node_by_phandle()")
Reported-by: NAlan Tull <atull@kernel.org>
Suggested-by: NAlan Tull <atull@kernel.org>
Signed-off-by: NFrank Rowand <frank.rowand@sony.com>
Signed-off-by: NRob Herring <robh@kernel.org>

Create a cache of the nodes that contain a phandle property.  Use this
cache to find the node for a given phandle value instead of scanning
the devicetree to find the node.  If the phandle value is not found
in the cache, of_find_node_by_phandle() will fall back to the tree
scan algorithm.

The cache is initialized in of_core_init().

The cache is freed via a late_initcall_sync() if modules are not
enabled.

If the devicetree is created by the dtc compiler, with all phandle
property values auto generated, then the size required by the cache
could be 4 * (1 + number of phandles) bytes.  This results in an O(1)
node lookup cost for a given phandle value.  Due to a concern that the
phandle property values might not be consistent with what is generated
by the dtc compiler, a mask has been added to the cache lookup algorithm.
To maintain the O(1) node lookup cost, the size of the cache has been
increased by rounding the number of entries up to the next power of
two.

The overhead of finding the devicetree node containing a given phandle
value has been noted by several people in the recent past, in some cases
with a patch to add a hashed index of devicetree nodes, based on the
phandle value of the node.  One concern with this approach is the extra
space added to each node.  This patch takes advantage of the phandle
property values auto generated by the dtc compiler, which begin with
one and monotonically increase by one, resulting in a range of 1..n
for n phandle values.  This implementation should also provide a good
reduction of overhead for any range of phandle values that are mostly
in a monotonic range.

Performance measurements by Chintan Pandya <cpandya@codeaurora.org>
of several implementations of patches that are similar to this one
suggest an expected reduction of boot time by ~400ms for his test
system.  If the cache size was decreased to 64 entries, the boot
time was reduced by ~340 ms.  The measurements were on a 4.9.73 kernel
for arch/arm64/boot/dts/qcom/sda670-mtp.dts, contains 2371 nodes and
814 phandle values.
Reported-by: NChintan Pandya <cpandya@codeaurora.org>
Signed-off-by: NFrank Rowand <frank.rowand@sony.com>
Signed-off-by: NRob Herring <robh@kernel.org>

Platforms like 96boards have a standardized connector/expansion
slot that exposes signals like GPIOs to expansion boards in an
SoC agnostic way. We'd like the DT overlays for the expansion
boards to be written once without knowledge of the SoC on the
other side of the connector. This avoids the unscalable
combinatorial explosion of a different DT overlay for each
expansion board and SoC pair.

We need a way to describe the GPIOs routed through the connector
in an SoC agnostic way. Let's introduce nexus property parsing
into the OF core to do this. This is largely based on the
interrupt nexus support we already have. This allows us to remap
a phandle list in a consumer node (e.g. reset-gpios) through a
connector in a generic way (e.g. via gpio-map). Do this in a
generic routine so that we can remap any sort of variable length
phandle list.

Taking GPIOs as an example, the connector would be a GPIO nexus,
supporting the remapping of a GPIO specifier space to multiple
GPIO providers on the SoC. DT would look as shown below, where
'soc_gpio1' and 'soc_gpio2' are inside the SoC, 'connector' is an
expansion port where boards can be plugged in, and
'expansion_device' is a device on the expansion board.

	soc {
		soc_gpio1: gpio-controller1 {
			#gpio-cells = <2>;
		};

		soc_gpio2: gpio-controller2 {
			#gpio-cells = <2>;
		};
	};

	connector: connector {
		#gpio-cells = <2>;
		gpio-map = <0 0 &soc_gpio1 1 0>,
			   <1 0 &soc_gpio2 4 0>,
			   <2 0 &soc_gpio1 3 0>,
			   <3 0 &soc_gpio2 2 0>;
		gpio-map-mask = <0xf 0x0>;
		gpio-map-pass-thru = <0x0 0x1>
	};

	expansion_device {
		reset-gpios = <&connector 2 GPIO_ACTIVE_LOW>;
	};

The GPIO core would use of_parse_phandle_with_args_map() instead
of of_parse_phandle_with_args() and arrive at the same type of
result, a phandle and argument list. The difference is that the
phandle and arguments will be remapped through the nexus node to
the underlying SoC GPIO controller node. In the example above,
we would remap 'reset-gpios' from <&connector 2 GPIO_ACTIVE_LOW>
to <&soc_gpio1 3 GPIO_ACTIVE_LOW>.

Cc: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: NStephen Boyd <stephen.boyd@linaro.org>
Signed-off-by: NRob Herring <robh@kernel.org>

Convert remaining DT files to use SPDX-License-Identifier tags.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Reviewed-by: NFrank Rowand <frank.rowand@sony.com>
Reviewed-by: NPhilippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: NRob Herring <robh@kernel.org>

Add a helper to map a device node to a logical CPU number to avoid
duplication. Currently this is open coded in different places (e.g
gic-v3, coresight). The helper tries to map device node to a "possible"
logical CPU id, which may not be online yet. It is the responsibility
of the user to make sure that the CPU is online. The helper uses
of_cpu_device_node_get() to retrieve the device node for a given CPU
(which uses per_cpu data if available else falls back to slower
of_get_cpu_node()).

Cc: devicetree@vger.kernel.org
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: NMarc Zyngier <marc.zyngier@arm.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

It isn't clear if this function of_node_put()s the 'from'
argument, or the node it searches. Clearly indicate which
variable is touched. Fold in some more fixes from Randy too
because we're in the area.

Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Acked-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NRob Herring <robh@kernel.org>

The "%pOF" printf format was recently added to print the
full name of a device tree node, with the intent of changing
the node full_name field to contain only the node name instead
of the full path of the node.

dup_and_fixup_symbol_prop() duplicates a property from the
"/__symbols__" node of an overlay device tree.  The value
of each duplicated property must be fixed up to include
the full path of a node in the live device tree.  The
current code uses the node's full_name for that purpose.
Update the code to use the "%pOF" printf format to
determine the node's full path.
Signed-off-by: NFrank Rowand <frank.rowand@sony.com>
Signed-off-by: NRob Herring <robh@kernel.org>

Having device_nodes be kobjects is only needed if sysfs or OF_DYNAMIC is
enabled. Otherwise, having a kobject in struct device_node is
unnecessary bloat in minimal kernel configurations.

Likewise, bin_attribute is only needed in struct property when sysfs is
enabled, so we can make it configurable too.
Tested-by: NNicolas Pitre <nico@linaro.org>
Reviewed-by: NFrank Rowand <frowand.list@gmail.com>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NRob Herring <robh@kernel.org>

The ref counting is broken for OF_DYNAMIC when sysfs is disabled because
the kobject initialization is skipped. Only the properties
add/remove/update should be skipped for !SYSFS config.
Tested-by: NNicolas Pitre <nico@linaro.org>
Reviewed-by: NFrank Rowand <frowand.list@gmail.com>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NRob Herring <robh@kernel.org>

Do not strdup() console options. It seems that the only reason for
it to be strdup()-ed was a compilation warning: printk, UART and
console drivers, for some reason, expect char pointer instead of
const char pointer. So we can just pass `of_stdout_options', but
need to cast it to char pointer. A better fix would be to change
printk, console drivers and UART to accept const char `options';
but that will take time - there are lots of drivers to update.

The patch also fixes a possible memory leak: add_preferred_console()
can fail, but we don't kfree() options.
Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: NPetr Mladek <pmladek@suse.com>
Signed-off-by: NRob Herring <robh@kernel.org>

of_alias_scan() can use of_property_read_string() -- using the modern DT API
adds some prop sanity checks as a bonus; it does add couple LoCs but only
because the original code violated the 80-column limit...
Signed-off-by: NSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: NRob Herring <robh@kernel.org>

of_n_{addr|size}_cells() predate of_property_read_u32(), so they have to
basically open-code it. Using the modern DT API saves several LoCs and also
adds some prop sanity checks as a bonus...
Signed-off-by: NSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: NRob Herring <robh@kernel.org>

Now that we have a custom printf format specifier, convert users of
full_name to use %pOF instead. This is preparation to remove storing
of the full path string for each node.
Signed-off-by: NRob Herring <robh@kernel.org>

find_node_by_full_name() does the same thing as of_find_node_by_path(),
but takes no locks and doesn't work on aliases. Refactor
of_find_node_opts_by_path() into __of_find_node_by_full_path() and
replace find_node_by_full_name() with it.
Signed-off-by: NRob Herring <robh@kernel.org>

Several places in DT code open code the equivalent of kbasename.
Replace them.

The behavior for root nodes in node_name_cmp will be slightly different.
Instead of comparing "/", "" will be compared. The comparison will be
the same.
Reviewed-by: NAndy Shevchenko <andy.shevhchenko@gmail.com>
Signed-off-by: NRob Herring <robh@kernel.org>

checkpatch whined about using S_IRUGO instead of octal equivalent
when adding phandle sysfs code, so used octal in that pending patch.
Change other instances of the S_* constants in the same file to
the octal form.
Signed-off-by: NFrank Rowand <frank.rowand@sony.com>
Signed-off-by: NRob Herring <robh@kernel.org>

base.c contains both core OF functions and increasingly other
functionality such as accessing properties and graphs, including
convenience functions. In the near future this would also include OF
specific implementation of the fwnode property and graph APIs.

Create driver/of/property.c to contain procedures for accessing and
interpreting device tree properties. The procedures are moved from
drivers/of/base.c, with no changes other than copying only the includes
required by the moved procedures.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NRob Herring <robh@kernel.org>

OF graph want to count its endpoint number, same as
of_get_child_count(). This patch adds of_graph_get_endpoint_count()
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

Linux kernel already has of_graph_get_remote_port_parent(),
but, sometimes we want to get own port parent.
This patch adds of_graph_get_port_parent()
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NMark Brown <broonie@kernel.org>