Fixes the following W=1 kernel build warning(s):

 drivers/of/base.c:1781: warning: Function parameter or member 'prop' not described in '__of_add_property'
 drivers/of/base.c:1781: warning: Excess function parameter 'prob' description in '__of_add_property'
 drivers/of/base.c:1804: warning: Function parameter or member 'prop' not described in 'of_add_property'
 drivers/of/base.c:1804: warning: Excess function parameter 'prob' description in 'of_add_property'
 drivers/of/base.c:1855: warning: Function parameter or member 'prop' not described in 'of_remove_property'
 drivers/of/base.c:1855: warning: Excess function parameter 'prob' description in 'of_remove_property'

Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: devicetree@vger.kernel.org
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20210329152435.900225-1-lee.jones@linaro.orgSigned-off-by: NRob Herring <robh@kernel.org>

Many of the DT kerneldoc comments are lacking a 'Return' section. Let's
add the section in cases we have a description of return values. There's
still some cases where the return values are not documented.

Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: NRob Herring <robh@kernel.org>
Reviewed-by: NMauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/20210325164713.1296407-8-robh@kernel.org

The indentation of the kerneldoc comments affects the output formatting.
Leading tabs in particular don't work, sections need to be indented
under the section header, and several code blocks are reformatted.

Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: NRob Herring <robh@kernel.org>
Reviewed-by: NMauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/20210326192606.3702739-1-robh@kernel.org

Fixes the following W=1 kernel build warning(s):

 drivers/of/base.c:315: warning: Function parameter or member 'cpun' not described in '__of_find_n_match_cpu_property'
 drivers/of/base.c:315: warning: Function parameter or member 'prop_name' not described in '__of_find_n_match_cpu_property'
 drivers/of/base.c:315: warning: Function parameter or member 'cpu' not described in '__of_find_n_match_cpu_property'
 drivers/of/base.c:315: warning: Function parameter or member 'thread' not described in '__of_find_n_match_cpu_property'
 drivers/of/base.c:315: warning: expecting prototype for property holds the physical id of the(). Prototype was for __of_find_n_match_cpu_property() instead
 drivers/of/base.c:1139: warning: Function parameter or member 'match' not described in 'of_find_matching_node_and_match'
 drivers/of/base.c:1779: warning: Function parameter or member 'np' not described in '__of_add_property'
 drivers/of/base.c:1779: warning: Function parameter or member 'prop' not described in '__of_add_property'
 drivers/of/base.c:1800: warning: Function parameter or member 'np' not described in 'of_add_property'
 drivers/of/base.c:1800: warning: Function parameter or member 'prop' not described in 'of_add_property'
 drivers/of/base.c:1849: warning: Function parameter or member 'np' not described in 'of_remove_property'
 drivers/of/base.c:1849: warning: Function parameter or member 'prop' not described in 'of_remove_property'
 drivers/of/base.c:2137: warning: Function parameter or member 'dn' not described in 'of_console_check'
 drivers/of/base.c:2137: warning: Function parameter or member 'name' not described in 'of_console_check'
 drivers/of/base.c:2137: warning: Function parameter or member 'index' not described in 'of_console_check'

Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: devicetree@vger.kernel.org
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NRob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210318104036.3175910-5-lee.jones@linaro.org

Also print out the phandle ID on error message, as a debug aid.
Signed-off-by: NEnrico Weigelt, metux IT consult <info@metux.net>
Link: https://lore.kernel.org/r/20210114101127.16580-1-info@metux.netSigned-off-by: NRob Herring <robh@kernel.org>

We will need to remove some OF properties in drivers/net/dsa/bcm_sf2.c
with a subsequent commit. Export of_remove_property() to modules so we
can keep bcm_sf2 modular and provide an empty stub for when CONFIG_OF is
disabled to maintain the ability to compile test.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

There is nothing PCI specific (other than the RID - requester ID)
in the of_map_rid() implementation, so the same function can be
reused for input/output IDs mapping for other busses just as well.

Rename the RID instances/names to a generic "id" tag.

No functionality change intended.
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Acked-by: NJoerg Roedel <jroedel@suse.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200619082013.13661-7-lorenzo.pieralisi@arm.comSigned-off-by: NCatalin Marinas <catalin.marinas@arm.com>

The CPU's idle state nodes are currently parsed at the common cpuidle DT
library, but also when initializing data for specific CPU idle operations,
as in the PSCI cpuidle driver case and qcom-spm cpuidle case.

To avoid open-coding, let's introduce of_get_cpu_state_node(), which takes
the device node for the CPU and the index to the requested idle state node,
as in-parameters. In case a corresponding idle state node is found, it
returns the node with the refcount incremented for it, else it returns
NULL.

Moreover, for PSCI there are two options to describe the CPU's idle states
[1], either via a flattened description or a hierarchical layout. Hence,
let's take both options into account.

[1] Documentation/devicetree/bindings/arm/psci.yaml
Suggested-by: NSudeep Holla <sudeep.holla@arm.com>
Co-developed-by: NLina Iyer <lina.iyer@linaro.org>
Signed-off-by: NLina Iyer <lina.iyer@linaro.org>
Reviewed-by: NRob Herring <robh@kernel.org>
Reviewed-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NSudeep Holla <sudeep.holla@arm.com>

The phandle cache was added to speed up of_find_node_by_phandle() by
avoiding walking the whole DT to find a matching phandle. The
implementation has several shortcomings:

  - The cache is designed to work on a linear set of phandle values.
    This is true for dtc generated DTs, but not for other cases such as
    Power.
  - The cache isn't enabled until of_core_init() and a typical system
    may see hundreds of calls to of_find_node_by_phandle() before that
    point.
  - The cache is freed and re-allocated when the number of phandles
    changes.
  - It takes a raw spinlock around a memory allocation which breaks on
    RT.

Change the implementation to a fixed size and use hash_32() as the
cache index. This greatly simplifies the implementation. It avoids
the need for any re-alloc of the cache and taking a reference on nodes
in the cache. We only have a single source of removing cache entries
which is of_detach_node().

Using hash_32() removes any assumption on phandle values improving
the hit rate for non-linear phandle values. The effect on linear values
using hash_32() is about a 10% collision. The chances of thrashing on
colliding values seems to be low.

To compare performance, I used a RK3399 board which is a pretty typical
system. I found that just measuring boot time as done previously is
noisy and may be impacted by other things. Also bringing up secondary
cores causes some issues with measuring, so I booted with 'nr_cpus=1'.
With no caching, calls to of_find_node_by_phandle() take about 20124 us
for 1248 calls. There's an additional 288 calls before time keeping is
up. Using the average time per hit/miss with the cache, we can calculate
these calls to take 690 us (277 hit / 11 miss) with a 128 entry cache
and 13319 us with no cache or an uninitialized cache.

Comparing the 3 implementations the time spent in
of_find_node_by_phandle() is:

no cache:        20124 us (+ 13319 us)
128 entry cache:  5134 us (+ 690 us)
current cache:     819 us (+ 13319 us)

We could move the allocation of the cache earlier to improve the
current cache, but that just further complicates the situation as it
needs to be after slab is up, so we can't do it when unflattening (which
uses memblock).
Reported-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Segher Boessenkool <segher@kernel.crashing.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: NFrank Rowand <frowand.list@gmail.com>
Tested-by: NFrank Rowand <frowand.list@gmail.com>
Signed-off-by: NRob Herring <robh@kernel.org>

In some cases such as PCI host controllers, we may have a "parent bus"
which is an OF leaf node, but still need to correctly parse ranges from
the point of view of that bus. For that, factor out variants of the
"#addr-cells" and "#size-cells" parsers which do not assume they have a
device node and thus immediately traverse upwards before reading the
relevant property.
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
[robh: don't make of_bus_n_{addr,size}_cells() public]
Reviewed-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Tested-by: NNicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: NNicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: NRob Herring <robh@kernel.org>

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>