reset: Instantiate reset GPIO controller for shared reset-gpios

Devices sharing a reset GPIO could use the reset framework for
coordinated handling of that shared GPIO line. We have several cases o

reset: Instantiate reset GPIO controller for shared reset-gpios

Devices sharing a reset GPIO could use the reset framework for
coordinated handling of that shared GPIO line. We have several cases of
such needs, at least for Devicetree-based platforms.

If Devicetree-based device requests a reset line, while "resets"
Devicetree property is missing but there is a "reset-gpios" one,
instantiate a new "reset-gpio" platform device which will handle such
reset line. This allows seamless handling of such shared reset-gpios
without need of changing Devicetree binding [1].

To avoid creating multiple "reset-gpio" platform devices, store the
Devicetree "reset-gpios" GPIO specifiers used for new devices on a
linked list. Later such Devicetree GPIO specifier (phandle to GPIO
controller, GPIO number and GPIO flags) is used to check if reset
controller for given GPIO was already registered.

If two devices have conflicting "reset-gpios" property, e.g. with
different ACTIVE_xxx flags, this would allow to spawn two separate
"reset-gpio" devices, where the second would fail probing on busy GPIO
request.

Link: https://lore.kernel.org/all/[email protected]/ [1]
Cc: Bartosz Golaszewski <[email protected]>
Cc: Chris Packham <[email protected]>
Cc: Sean Anderson <[email protected]>
Reviewed-by: Philipp Zabel <[email protected]>
Signed-off-by: Krzysztof Kozlowski <[email protected]>
Acked-by: Bartosz Golaszewski <[email protected]>
Acked-by: Linus Walleij <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Philipp Zabel <[email protected]>

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reset: Add compile-test stubs

Add stubs for the reset controller registration functions to allow
building reset controller provider drivers with the COMPILE_TEST
Kconfig option enabled.

Reported-by

reset: Add compile-test stubs

Add stubs for the reset controller registration functions to allow
building reset controller provider drivers with the COMPILE_TEST
Kconfig option enabled.

Reported-by: Krzysztof Kozlowski <[email protected]>
Suggested-by: Dmitry Osipenko <[email protected]>
Signed-off-by: Thierry Reding <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Philipp Zabel <[email protected]>

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reset: fix reset_control_ops kerneldoc comment

Add a missing short description to the reset_control_ops documentation.

Signed-off-by: Randy Dunlap <[email protected]>
[[email protected]: r

reset: fix reset_control_ops kerneldoc comment

Add a missing short description to the reset_control_ops documentation.

Signed-off-by: Randy Dunlap <[email protected]>
[[email protected]: rebased and updated commit message]
Signed-off-by: Philipp Zabel <[email protected]>

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reset: improve of_xlate documentation

Mention of_reset_simple_xlate as the default if of_xlate is not set.

Signed-off-by: Philipp Zabel <[email protected]>

reset: fix reset_control_lookup kerneldoc comment

Add a missing colon to fix a documentation build warning:

./include/linux/reset-controller.h:45: warning: Function parameter or member 'con_id' n

reset: fix reset_control_lookup kerneldoc comment

Add a missing colon to fix a documentation build warning:

./include/linux/reset-controller.h:45: warning: Function parameter or member 'con_id' not described in 'reset_control_lookup'

Fixes: 6691dffab0ab ("reset: add support for non-DT systems")
Signed-off-by: Philipp Zabel <[email protected]>

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reset: modify the way reset lookup works for board files

Commit 7af1bb19f1d7 ("reset: add support for non-DT systems")
introduced reset control lookup mechanism for boards that still use
board files

reset: modify the way reset lookup works for board files

Commit 7af1bb19f1d7 ("reset: add support for non-DT systems")
introduced reset control lookup mechanism for boards that still use
board files.

The routine used to register lookup entries takes the corresponding
reset_controlled_dev structure as argument.

It's been determined however that for the first user of this new
interface - davinci psc driver - it will be easier to register the
lookup entries using the reset controller device name.

This patch changes the way lookup entries are added.

Signed-off-by: Bartosz Golaszewski <[email protected]>
[[email protected]: added missing ERR_PTR]
Signed-off-by: Philipp Zabel <[email protected]>

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reset: add support for non-DT systems

The reset framework only supports device-tree. There are some platforms
however, which need to use it even in legacy, board-file based mode.

An example of such

reset: add support for non-DT systems

The reset framework only supports device-tree. There are some platforms
however, which need to use it even in legacy, board-file based mode.

An example of such architecture is the DaVinci family of SoCs which
supports both device tree and legacy boot modes and we don't want to
introduce any regressions.

We're currently working on converting the platform from its hand-crafted
clock API to using the common clock framework. Part of the overhaul will
be representing the chip's power sleep controller's reset lines using
the reset framework.

This changeset extends the core reset code with a new reset lookup
entry structure. It contains data allowing the reset core to associate
reset lines with devices by comparing the dev_id and con_id strings.

It also provides a function allowing drivers to register lookup entries
with the framework.

The new lookup function is only called as a fallback in case the
of_node field is NULL and doesn't change anything for current users.

Tested with a dummy reset driver with several lookup entries.

An example lookup table registration from a driver can be found below:

static struct reset_control_lookup foobar_reset_lookup[] = {
RESET_LOOKUP("foo.0", "foo", 15),
RESET_LOOKUP("bar.0", NULL, 5),
};

foobar_probe()
{
...

reset_controller_add_lookup(&rcdev, foobar_reset_lookup,
ARRAY_SIZE(foobar_reset_lookup));

...
}

Cc: Sekhar Nori <[email protected]>
Cc: Kevin Hilman <[email protected]>
Cc: David Lechner <[email protected]>
Signed-off-by: Bartosz Golaszewski <[email protected]>
Signed-off-by: Philipp Zabel <[email protected]>

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <[email protected]>
Reviewed-by: Philippe Ombredanne <[email protected]>
Reviewed-by: Thomas Gleixner <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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reset: add devm_reset_controller_register API

Add a device managed API for reset_controller_register().

This helps in reducing code in .remove callbacks and sometimes
dropping .remove callbacks ent

reset: add devm_reset_controller_register API

Add a device managed API for reset_controller_register().

This helps in reducing code in .remove callbacks and sometimes
dropping .remove callbacks entirely.

Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Laxman Dewangan <[email protected]>
Signed-off-by: Philipp Zabel <[email protected]>

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reset: Share struct reset_control between reset_control_get calls

Now that struct reset_control no longer stores the device pointer for
the device calling reset_control_get we can share a single str

reset: Share struct reset_control between reset_control_get calls

Now that struct reset_control no longer stores the device pointer for
the device calling reset_control_get we can share a single struct
reset_control when multiple calls to reset_control_get are made for
the same reset line (same id / index).

This is a preparation patch for adding support for shared reset lines.

Signed-off-by: Hans de Goede <[email protected]>
Signed-off-by: Philipp Zabel <[email protected]>

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reset: Make reset_control_ops const

The ops pointer is holding a pointer to a structure that is usually not
modified. Make it const.

Signed-off-by: Maxime Ripard <[email protected]>

reset: Make reset_control_ops const

The ops pointer is holding a pointer to a structure that is usually not
modified. Make it const.

Signed-off-by: Maxime Ripard <[email protected]>
Signed-off-by: Philipp Zabel <[email protected]>

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reset: add reset_control_status helper function

There are cases where a system will want to read a reset status bit before
doing any other toggling. Add a reset_control_status helper function to the

reset: add reset_control_status helper function

There are cases where a system will want to read a reset status bit before
doing any other toggling. Add a reset_control_status helper function to the
reset controller API.

Signed-off-by: Dinh Nguyen <[email protected]>
Signed-off-by: Philipp Zabel <[email protected]>

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reset: Silence warning in reset-controller.h

If a user of <linux/reset-controller.h> doesn't include
<linux/of.h> before including reset-controller.h they'll get a
warning as follows:

include/lin

reset: Silence warning in reset-controller.h

If a user of <linux/reset-controller.h> doesn't include
<linux/of.h> before including reset-controller.h they'll get a
warning as follows:

include/linux/reset-controller.h:44:17:
warning: 'struct of_phandle_args' declared inside parameter list

This is because of_phandle_args is not forward declared. Add the
declaration to silence this warning.

Acked-by: Philipp Zabel <[email protected]>
Signed-off-by: Stephen Boyd <[email protected]>
Signed-off-by: Mike Turquette <[email protected]>

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reset: Add reset controller API

This adds a simple API for devices to request being reset
by separate reset controller hardware and implements the
reset signal device tree binding.

Signed-off-by: P

reset: Add reset controller API

This adds a simple API for devices to request being reset
by separate reset controller hardware and implements the
reset signal device tree binding.

Signed-off-by: Philipp Zabel <[email protected]>
Reviewed-by: Stephen Warren <[email protected]>
Reviewed-by: Shawn Guo <[email protected]>
Reviewed-by: Marek Vasut <[email protected]>
Reviewed-by: Pavel Machek <[email protected]>

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