regulator: s2mpa01: Drop useless header

The TPS65910 includes the legacy header <linux/gpio.h> for no
reason, drop the include.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20230808-descriptors-regulator-v1-2-939b5e84dd18@linaro.org
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: s2mpa01: Drop initialization via platform data

None of the platforms with S2MPA01 use board files, so any
initialization via platform data can be safely removed.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20210420170244.13467-4-krzysztof.kozlowski@canonical.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: samsung: Rename Samsung to lowercase

Fix up inconsistent usage of upper and lowercase letters in "Samsung"
name.

"SAMSUNG" is not an abbreviation but a regular trademarked name.
Therefore it should be written with lowercase letters starting with
capital letter.

Although advertisement materials usually use uppercase "SAMSUNG", the
lowercase version is used in all legal aspects (e.g. on Wikipedia and in
privacy/legal statements on
https://www.samsung.com/semiconductor/privacy-global/).

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20200103171131.9900-20-krzk@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: s2mpa01: Remove unused define for S2MPA01_REGULATOR_CNT

The S2MPA01_REGULATOR_CNT is no longer used after converted to use
simplified DT parsing.

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

regulator: s2mpa01: Convert to use simplified DT parsing

Use regulator core's simplified DT parsing code to simply the driver
implementation.

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

regulator: s2mpa01: Fix step values for some LDOs

The step values for some of the LDOs appears to be incorrect, resulting
in incorrect voltages (or at least, ones which are different from the
Samsung 3.4 vendor kernel).

Signed-off-by: Stuart Menefy <stuart.menefy@mathembedded.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

regulator: samsung: Add SPDX license identifiers

Replace GPL v2.0+ license statements with SPDX license
identifiers.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: s2mpa01: Fix inconsistent indenting

Broken indenting makes code more difficult to read and brings
confusion. Fix warning reported by Smatch:
s2mpa01.c:362 s2mpa01_pmic_probe() warn: inconsistent indenting

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: s2mpa01: Constify regulator_ops

Static struct regulator_ops is not modified so can be made const for
code safeness.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: s2mpa01: reduce stack size for probe function

In some rare configurations we can run into rather high kernel stack
consumption:

drivers/regulator/s2mpa01.c:397:1: error: the frame size of 1536 bytes is larger than 1152 bytes [-Werror=frame-larger-than=]

This is probably harmless since it happens only in the probe function,
but there is also a relatively simple workaround, moving the regulator
match data into the device specific structure.

As a small downside, we waste a little memory at runtime. An alternative
approach would free the array at the end of the probe function, which in
turn is a little more complicated.

Fixes: f18792714608 ("regulator: Add support for S2MPA01 regulator")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: s2mpa01: zero-initialize regulator match table array

The struct of_regulator_match rmatch[] is declared as a non-static local
variable so the structure members are not auto-initialized.

Initialize the array at declaration time to avoid the structure members
values to be indeterminate and have sane defaults instead.

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: s2mpa01: Make regulator_desc array const

The regulator_register() expects array of 'regulator_desc' to be const.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: drop owner assignment from platform_drivers

A platform_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

regulator: s2mpa01: Optimize the regulator description macro

This patch makes the regulator description macro take minimum and
steps voltage as parameter. In this way many repeated macros can be
removed. Now these macros are repeated only if the the LDO/BUCK ctrl
registers have non-linear positions. The good thing is these ctrl registers
are mostly linear so they are not passed as parameters.

This patch reduces the code size and also allow easy addition of more
s2mpxxx PMIC drivers which differs a lot in minimum/step voltages.

Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Amit Daniel Kachhap <amit.daniel@samsung.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regulator: s2mpxxx: Move regulator min/step voltages in common place

This is a cleanup patch and moves min/step voltages in a common samsung
header file so that they can be used by other s2mpxxx PMIC drivers. Only
few required macros are added currently and others can be added if needed.

Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Amit Daniel Kachhap <amit.daniel@samsung.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

regulator: s2mpa01: Use correct register for buck1 ramp delay

Fix the register for ramp delay of buck1 regulator. Buck1 and buck6
share the field (offset 4) in ramp delay register S2MPA01_REG_RAMP2.

The driver used the same register and field for ramp delay of buck3 and
buck1. This lead to updating of ramp delay of buck3 when setting buck1
and actually the ramp delay of buck1 was never set.

Fixes: f18792714608 ("regulator: Add support for S2MPA01 regulator")
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
Cc: <stable@vger.kernel.org>

regulator: s2mpa01: Use rdev_get_id() to access id of regulator

Use regulator API rdev_get_id() to access id of regulator.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regulator: s2mpa01: Fix accidental enable of buck4 ramp delay

S2MPA01 supports enabling/disabling ramp delay only for buck[1234].
Other bucks have ramp delay enabled always.

However the bit shift for enabling buck4 ramp delay in register is equal
to 0. When ramp delay was set for the bucks unsupporting enable/disable
(buck[56789] and buck10), the ramp delay for buck4 was also enabled.

Fixes: f7b1a8dc1c1c ("regulator: s2mpa01: Don't check enable_shift before setting enable ramp rate")
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regulator: s2mpa01: Don't check enable_shift before setting enable ramp rate

Current code misses updating the register when enable_shift is 0.
e.g. S2MPA01_BUCK4_RAMP_EN_SHIFT is 0.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

regulator: Add support for S2MPA01 regulator

Add support for S2MPA01 voltage and current regulator.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Acked-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>