leds: Convert all platform drivers to return void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.
To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new() which already returns void. Eventually after all drivers
are converted, .remove_new() is renamed to .remove().

All platform drivers below drivers/leds/ unconditionally return zero in
their remove callback and so can be converted trivially to the variant
returning void.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230917130947.1122198-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Lee Jones <lee@kernel.org>

leds: flash: leds-qcom-flash: Put child node if registration failed

Put the child node if register flash LED device failed.

Signed-off-by: Fenglin Wu <quic_fenglinw@quicinc.com>
Link: https://lore.kernel.org/r/20230725-leds-qcom-flash-driver-tiny-fixes-v2-3-0f5cbce5fed0@quicinc.com
Signed-off-by: Lee Jones <lee@kernel.org>

leds: flash: leds-qcom-flash: Turn off LED before setting flash current

Strobe off the LED before setting flash current to avoid it's being
enabled with an incorrect current if it has been working in torch
mode.

Signed-off-by: Fenglin Wu <quic_fenglinw@quicinc.com>
Link: https://lore.kernel.org/r/20230725-leds-qcom-flash-driver-tiny-fixes-v2-2-0f5cbce5fed0@quicinc.com
Signed-off-by: Lee Jones <lee@kernel.org>

leds: flash: leds-qcom-flash: Fix an unsigned comparison which can never be negative

The variable 'count' is defined as unsigned type, so the following if
statement is invalid, we can modify the type of count to int.

if (count <= 0) {
dev_err(dev, "No led-sources specified\n");
return -ENODEV;
}

./drivers/leds/flash/leds-qcom-flash.c:546:5-10: WARNING: Unsigned expression compared with zero: count <= 0.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=5344
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230531053559.5702-1-jiapeng.chong@linux.alibaba.com

leds: flash: leds-qcom-flash: Disable LED when changing brightness

The Qualcomm PMI8998 PMIC requires the LED to be disabled when configuring
the brightness. Always disable the LED when setting the brightness and
re-enable it afterwards.

Signed-off-by: Dylan Van Assche <me@dylanvanassche.be>
Link: https://lore.kernel.org/r/20230507172941.364852-3-me@dylanvanassche.be
Signed-off-by: Lee Jones <lee@kernel.org>

leds: flash: leds-qcom-flash: Add PMI8998 support

Add subtype for the Qualcomm PMI8998 PMIC to support it besides the
PM8150 PMIC which has the same registers. Adjust the driver to recognize
both PMIC subtypes as a 3 channel LED driver.

Signed-off-by: Dylan Van Assche <me@dylanvanassche.be>
Link: https://lore.kernel.org/r/20230507172941.364852-2-me@dylanvanassche.be
Signed-off-by: Lee Jones <lee@kernel.org>

leds: flash: Set variables mvflash_{3,4}ch_regs storage-class-specifier to static

Smatch reports:

drivers/leds/flash/leds-qcom-flash.c:103:18: warning:
symbol 'mvflash_3ch_regs' was not declared. Should it be static?
drivers/leds/flash/leds-qcom-flash.c:115:18: warning:
symbol 'mvflash_4ch_regs' was not declared. Should it be static?

These variables are only used locally, so it should be static.

Signed-off-by: Tom Rix <trix@redhat.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230317191341.1670660-1-trix@redhat.com

leds: flash: Add driver to support flash LED module in QCOM PMICs

Add initial driver to support flash LED module found in Qualcomm
Technologies, Inc. PMICs. The flash module can have 3 or 4 channels
and each channel can be controlled indepedently and support full scale
current up to 1.5 A. It also supports connecting two channels together
to supply one LED component with full scale current up to 2 A. In that
case, the current will be split on each channel symmetrically and the
channels will be enabled and disabled at the same time.

Signed-off-by: Fenglin Wu <quic_fenglinw@quicinc.com>
Tested-by: Luca Weiss <luca.weiss@fairphone.com> # sm7225-fairphone-fp4 + pm6150l
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230303095023.538917-2-quic_fenglinw@quicinc.com