backlight: lm3630a_bl: Simplify probe return on gpio request error

Code can be simpler: return directly when devm_gpiod_get_optional()
failed.

Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240305-backlight-probe-v2-6-609b0cf24bde@linaro.org
Signed-off-by: Lee Jones <lee@kernel.org>

backlight: lm3630a_bl: Handle deferred probe

Don't pollute dmesg on deferred probe and simplify the code with
dev_err_probe().

Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240305-backlight-probe-v2-5-609b0cf24bde@linaro.org
Signed-off-by: Lee Jones <lee@kernel.org>

backlight: lm3630a: Use backlight_get_brightness helper in update_status

As per documentation "drivers are expected to use this function in their
update_status() operation to get the brightness value.".

With this we can also drop the manual backlight_is_blank() handling
since backlight_get_brightness() is already handling this correctly.

Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20240220-lm3630a-fixups-v1-3-9ca62f7e4a33@z3ntu.xyz
Signed-off-by: Lee Jones <lee@kernel.org>

backlight: lm3630a: Don't set bl->props.brightness in get_brightness

There's no need to set bl->props.brightness, the get_brightness function
is just supposed to return the current brightness and not touch the
struct.

With that done we can also remove the 'goto out' and just return the
value.

Fixes: 0c2a665a648e ("backlight: add Backlight driver for lm3630 chip")
Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20240220-lm3630a-fixups-v1-2-9ca62f7e4a33@z3ntu.xyz
Signed-off-by: Lee Jones <lee@kernel.org>

backlight: lm3630a: Initialize backlight_properties on init

The backlight_properties struct should be initialized to zero before
using, otherwise there will be some random values in the struct.

Fixes: 0c2a665a648e ("backlight: add Backlight driver for lm3630 chip")
Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20240220-lm3630a-fixups-v1-1-9ca62f7e4a33@z3ntu.xyz
Signed-off-by: Lee Jones <lee@kernel.org>

pwm: Rename pwm_apply_state() to pwm_apply_might_sleep()

In order to introduce a pwm api which can be used from atomic context,
we will need two functions for applying pwm changes:

int pwm_apply_might_sleep(struct pwm *, struct pwm_state *);
int pwm_apply_atomic(struct pwm *, struct pwm_state *);

This commit just deals with renaming pwm_apply_state(), a following
commit will introduce the pwm_apply_atomic() function.

Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> # for input
Acked-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Lee Jones <lee@kernel.org>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

backlight: 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.

Also fix two indention inconsistencies in the neighbourhood.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230521143844.375244-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Lee Jones <lee@kernel.org>

backlight: lm3630a: Turn off both led strings when display is blank

Use backlight_is_blank() to determine if the led strings should be turned
off in the update_status() functions of both strings.

Signed-off-by: Maximilian Weigand <mweigand@mweigand.net>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://lore.kernel.org/r/20230510085239.1253896-1-mweigand2017@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>

backlight: lm3630a: Convert to i2c's .probe_new()

The probe function doesn't make use of the i2c_device_id * parameter so it
can be trivially converted.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20221118224540.619276-590-uwe@kleine-koenig.org

i2c: Make remove callback return void

The value returned by an i2c driver's remove function is mostly ignored.
(Only an error message is printed if the value is non-zero that the
error is ignored.)

So change the prototype of the remove function to return no value. This
way driver authors are not tempted to assume that passing an error to
the upper layer is a good idea. All drivers are adapted accordingly.
There is no intended change of behaviour, all callbacks were prepared to
return 0 before.

Reviewed-by: Peter Senna Tschudin <peter.senna@gmail.com>
Reviewed-by: Jeremy Kerr <jk@codeconstruct.com.au>
Reviewed-by: Benjamin Mugnier <benjamin.mugnier@foss.st.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Crt Mori <cmo@melexis.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Marek Behún <kabel@kernel.org> # for leds-turris-omnia
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Petr Machata <petrm@nvidia.com> # for mlxsw
Reviewed-by: Maximilian Luz <luzmaximilian@gmail.com> # for surface3_power
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> # for bmc150-accel-i2c + kxcjk-1013
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> # for media/* + staging/media/*
Acked-by: Miguel Ojeda <ojeda@kernel.org> # for auxdisplay/ht16k33 + auxdisplay/lcd2s
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com> # for versaclock5
Reviewed-by: Ajay Gupta <ajayg@nvidia.com> # for ucsi_ccg
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # for iio
Acked-by: Peter Rosin <peda@axentia.se> # for i2c-mux-*, max9860
Acked-by: Adrien Grassein <adrien.grassein@gmail.com> # for lontium-lt8912b
Reviewed-by: Jean Delvare <jdelvare@suse.de> # for hwmon, i2c-core and i2c/muxes
Acked-by: Corey Minyard <cminyard@mvista.com> # for IPMI
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com> # for drivers/power
Acked-by: Krzysztof Hałasa <khalasa@piap.pl>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

backlight: lm3630a_bl: Remove redundant 'flush_workqueue()' calls

'destroy_workqueue()' already drains the queue before destroying it, so
there is no need to flush it explicitly.

Remove the redundant 'flush_workqueue()' calls.

Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Helge Deller <deller@gmx.de>

backlight: lm3630a: Convert to atomic PWM API and check for errors

The practical upside here is that this only needs a single API call to
program the hardware which (depending on the underlaying hardware) can
be more effective and prevents glitches.

Up to now the return value of the pwm functions was ignored. Fix this
and propagate the error to the caller.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

backlight: lm3630a: Fix return code of .update_status() callback

According to <linux/backlight.h> .update_status() is supposed to
return 0 on success and a negative error code otherwise. Adapt
lm3630a_bank_a_update_status() and lm3630a_bank_b_update_status() to
actually do it.

While touching that also add the error code to the failure message.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

backlight: lm3630a_bl: Put fwnode in error case during ->probe()

device_for_each_child_node() bumps a reference counting of a returned variable.
We have to balance it whenever we return to the caller.

Cc: Brian Masney <masneyb@onstation.org>
Cc: Dan Murphy <dmurphy@ti.com>
Fixes: 8fbce8efe15cd ("backlight: lm3630a: Add firmware node support")
Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Brian Masney <masneyb@onstation.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

backlight: lm3630a_bl: Remove invalid checks for unsigned int < 0

unsigned ints 'sources' and 'bank' cannot be less than LM3630A_SINK_0 (0)
and LM3630A_BANK_0 (0) respecitively, so change the logic to only check
for thier two possible valid values.

Fixes W=1 warnings:

drivers/video/backlight/lm3630a_bl.c: In function ‘lm3630a_parse_led_sources’:
drivers/video/backlight/lm3630a_bl.c:394:18: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]
394 | if (sources[i] < LM3630A_SINK_0 || sources[i] > LM3630A_SINK_1)
| ^
drivers/video/backlight/lm3630a_bl.c: In function ‘lm3630a_parse_bank’:
drivers/video/backlight/lm3630a_bl.c:415:11: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]
415 | if (bank < LM3630A_BANK_0 || bank > LM3630A_BANK_1)
| ^

Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Daniel Jeong <gshark.jeong@gmail.com>
Cc: LDD MLP <ldd-mlp@list.ti.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

backlight: lm3630a: Add an enable gpio for the HWEN pin

For now just enable it in the probe function to allow I2C
access. Disabling also means resetting the register values
to default and according to the datasheet does not give
power savings.

Tested on Kobo Clara HD.

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Reviewed-by: Dan Murphy <dmurphy@ti.com>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

backlight: lm3630a: Fix module aliases

Devicetree aliases are missing, so that module autoloading
does not work properly.

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

backlight: lm3630a: Switch to use fwnode_property_count_uXX()

Use use fwnode_property_count_uXX() directly, that makes code neater.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 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 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 #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

backlight: lm3630a: Add firmware node support

Add fwnode support to the lm3630a driver and optionally allow
configuring the label, default brightness level, and maximum brightness
level. The two outputs can be controlled by bank A and B independently
or bank A can control both outputs.

If the platform data was not configured, then the driver defaults to
enabling both banks. This patch changes the default value to disable
both banks before parsing the firmware node so that just a single bank
can be enabled if desired. There are no in-tree users of this driver.

Driver was tested on a LG Nexus 5 (hammerhead) phone.

Signed-off-by: Brian Masney <masneyb@onstation.org>
Reviewed-by: Dan Murphy <dmurphy@ti.com>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

backlight: lm3630a: Return 0 on success in update_status functions

lm3630a_bank_a_update_status() and lm3630a_bank_b_update_status()
both return the brightness value if the brightness was successfully
updated. Writing to these attributes via sysfs would cause a 'Bad
address' error to be returned. These functions should return 0 on
success, so let's change it to correct that error.

Fixes: 28e64a68a2ef ("backlight: lm3630: apply chip revision")
Signed-off-by: Brian Masney <masneyb@onstation.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

backlight: lm3630a: Bump REG_MAX value to 0x50 instead of 0x1F

In the lm3630a_chip_init we try to write to 0x50 register, which is
higher value then the max_register value, this resulted in regmap_write
return -EIO.

Fix this by bumping REG_MAX value to 0x50.

This code was introduced with the chip revision in commit 28e64a68a2ef,
however setting filter strength was failing silently because it used
unsigned int for storing and comparing the return values. Bug related to
signedness was fixed in 2a0c316bf3cc, which made it error out correctly
instead of failing silently.

I found this issue by using this driver on LGE Nexus 5 (hammerhead).
After this commit lm3630a_chip_init succeeds instead of failing with
-EIO.

Fixes: 28e64a68a2ef ("backlight: lm3630: apply chip revision")
Fixes: 2a0c316bf3cc ("drivers/video/backlight/lm3630a_bl.c: fix
signedness bug in lm3630a_chip_init()")

Suggested-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Bhushan Shah <bshah@kde.org>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

backlight: lm3630a: explicitly apply PWM config extracted from pwm_args

Call pwm_apply_args() just after requesting the PWM device so that the
polarity and period are initialized according to the information
provided in pwm_args.

This is an intermediate state, and pwm_apply_args() should be dropped as
soon as the atomic PWM infrastructure is in place and the driver makes
use of it.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

backlight: lm3630a_bl: Stop messing with the pwm->period field

pwm->period field is not supposed to be changed by PWM users. The only
ones authorized to change it are the PWM core and PWM drivers.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/video/backlight/lm3630a_bl.c: add missing destroy_workqueue() on error in lm3630a_intr_config()

Add the missing destroy_workqueue() before return from
lm3630a_intr_config() in the error handling case.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: use dev_get_platdata()

Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly. This is a cosmetic change to
make the code simpler and enhance the readability.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: lm3630: fix sparse warning

This patch is to fix sparse warning due to mixing different enum type.

Signed-off-by: Daniel Jeong <gshark.jeong@gmail.com>
Cc: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/video/backlight/lm3630a_bl.c: potential NULL deref in probe()

We dereference "pdata" later in the function so we can't leave it as NULL.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/video/backlight/lm3630a_bl.c: fix signedness bug in lm3630a_chip_init()

"rval" needs to be signed for the error handling to work.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: lm3630: apply chip revision

The LM3630 chip was revised by TI and chip name was also changed to
LM3630A. And register map, default values and initial sequences are
changed. The files, lm3630_bl.{c,h} are replaced by lm3630a_bl.{c,h} You
can find more information about LM3630A(datasheet, evm etc) at
http://www.ti.com/product/lm3630a

Signed-off-by: Daniel Jeong <gshark.jeong@gmail.com>
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>