regulator: ltc3676: Use maple tree register cache

The ltc3676 can only support single register read and write operations
so does not benefit from block writes. This means it gets no benefit from
using the rbtree register cache over the maple tree register cache so
convert it to use maple trees instead, it is more modern.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230609-regulator-ltc-maple-v1-2-08c15181f8b2@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Switch i2c drivers back to use .probe()

After commit b8a1a4cd5a98 ("i2c: Provide a temporary .probe_new()
call-back type"), all drivers being converted to .probe_new() and then
03c835f498b5 ("i2c: Switch .probe() to not take an id parameter") convert
back to (the new) .probe() to be able to eventually drop .probe_new() from
struct i2c_driver.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de
Link: https://lore.kernel.org/r/20230505220218.1239542-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org

regulator: Set PROBE_PREFER_ASYNCHRONOUS for drivers that existed in 4.14

Probing of regulators can be a slow operation and can contribute to
slower boot times. This is especially true if a regulator is turned on
at probe time (with regulator-boot-on or regulator-always-on) and the
regulator requires delays (off-on-time, ramp time, etc).

While the overall kernel is not ready to switch to async probe by
default, as per the discussion on the mailing lists [1] it is believed
that the regulator subsystem is in good shape and we can move
regulator drivers over wholesale. There is no way to just magically
opt in all regulators (regulators are just normal drivers like
platform_driver), so we set PROBE_PREFER_ASYNCHRONOUS for all
regulators found in 'drivers/regulator' individually.

Given the number of drivers touched and the impossibility to test this
ahead of time, it wouldn't be shocking at all if this caused a
regression for someone. If there is a regression caused by this patch,
it's likely to be one of the cases talked about in [1]. As a "quick
fix", drivers involved in the regression could be fixed by changing
them to PROBE_FORCE_SYNCHRONOUS. That being said, the correct fix
would be to directly fix the problem that caused the issue with async
probe.

The approach here follows a similar approach that was used for the mmc
subsystem several years ago [2]. In fact, I ran nearly the same python
script to auto-generate the changes. The only thing I changed was to
search for "i2c_driver", "spmi_driver", and "spi_driver" in addition
to "platform_driver".

[1] https://lore.kernel.org/r/06db017f-e985-4434-8d1d-02ca2100cca0@sirena.org.uk
[2] https://lore.kernel.org/r/20200903232441.2694866-1-dianders@chromium.org/

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20230316125351.1.I2a4677392a38db5758dee0788b2cea5872562a82@changeid
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: remove locking around regulator_notifier_call_chain()

regulator_notifier_call_chain() doesn't need rdev lock and rdev's
existence is assumed in the code anyway. Remove the locks from drivers.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Acked-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/42393f66dcc4d80dcd9797be45216b4035aa96cb.1597032945.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: ltc3676: Fix W=1 build warning when CONFIG_OF=n

Fix below warning when CONFIG_OF=n:

drivers/regulator/ltc3676.c:371:34: warning: ‘ltc3676_of_match’ defined but not used [-Wunused-const-variable=]
371 | static const struct of_device_id ltc3676_of_match[] = {
| ^~~~~~~~~~~~~~~~

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Link: https://lore.kernel.org/r/20200821111517.59d7b8c8@xhacker.debian
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: ltc3676: Constify ltc3676_regulators

ltc3676_regulators is not modified and can be made const to allow the
compiler to put it in read-only memory.

Before:
text data bss dec hex filename
4361 2064 8 6433 1921 drivers/regulator/ltc3676.o

After:
text data bss dec hex filename
6121 304 8 6433 1921 drivers/regulator/ltc3676.o

Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Link: https://lore.kernel.org/r/20200617223247.25566-4-rikard.falkeborn@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Convert i2c drivers to use .probe_new

Use the new .probe_new for i2c drivers.
These drivers do not use const struct i2c_device_id * argument, so convert
them to utilise the simplified i2c driver registration.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Link: https://lore.kernel.org/r/20200109155808.22003-1-axel.lin@ingics.com
Signed-off-by: Mark Brown <broonie@kernel.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 655 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

regulator: ltc3676: Fix notifier mutex lock warning

The mutex for the regulator_dev must be controlled by the caller of
the regulator_notifier_call_chain(), as described in the comment
for that function.

Failure to mutex lock and unlock surrounding the notifier call results
in a kernel WARN_ON_ONCE() which will dump a backtrace for the
regulator_notifier_call_chain() when that function call is first made.
The mutex can be controlled using the regulator_lock/unlock() API.

Fixes: 37b918a034fe ("regulator: Add LTC3676 support")
Suggested-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Signed-off-by: Steve Twiss <stwiss.opensource@diasemi.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: ltc3676: Fix module description

This driver is for LTC3676 rather than LTC1376.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: ltc3676: Simplify .readable_reg and .writable_reg callbacks

Use case range for continuous range to make the code shorter.
The .readable_reg and .writable_reg implementation are exactly the same,
so use a common ltc3676_readable_writeable_reg function instead.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: split up regmap_config.use_single_rw

Split regmap_config.use_single_rw into use_single_read and
use_single_write. This change enables drivers of devices which only
support bulk operations in one direction to use the regmap_bulk_*()
functions for both directions and have their bulk operation split into
single operations only when necessary.

Update all struct regmap_config instances where use_single_rw==true to
instead set both use_single_read and use_single_write. No attempt was
made to evaluate whether it is possible to set only one of
use_single_read or use_single_write.

Signed-off-by: David Frey <dpfrey@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: ltc3676: Assure PGOOD mask is set before changing voltage

Make sure the DVBxB bit 5, PGOOD mask, is set before changing voltage
on the buck converters. If the PGOOD mask bit is not set, the PMIC may
deassert the PGOOD signal during the voltage transition.

On systems that use the PGOOD signal as a power OK indication for the
board or SoC, which should be the case on correct designs, deasserting
the PGOOD signal will lead to system reset or shutdown, which is not
the expected behavior when changing PMIC buck converter voltage.

Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: ltc3676: Add OF device ID table

The driver doesn't have a struct of_device_id table but supported devices
are registered via Device Trees. This is working on the assumption that a
I2C device registered via OF will always match a legacy I2C device ID and
that the MODALIAS reported will always be of the form i2c:<device>.

But this could change in the future so the correct approach is to have an
OF device ID table if the devices are registered via OF.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: ltc3676: constify regulator_ops structure

Declare regulator_ops structure as const as it is only stored in the ops
field of a regulator_desc structure. This field is of type const, so
regulator_ops structures having this property can be made const too.

File size before: drivers/regulator/ltc3676.o
text data bss dec hex filename
2369 2808 288 5465 1559 drivers/regulator/ltc3676.o

File size after: drivers/regulator/ltc3676.o
text data bss dec hex filename
3145 2296 8 5449 1549 drivers/regulator/ltc3676.o

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Add LTC3676 support

This patch adds support for the Linear Technology LTC3676
8-output I2C voltage regulator IC.

Cc: Jaffer Kapasi <jkapasi@linear.com>
Signed-off-by: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Mark Brown <broonie@kernel.org>