[ Upstream commit 2ccfe94bc3ac980d2d1df9f7a0b2c6d2137abe55 ]

The reference count is bumped by device_get_named_child_node()
and never dropped. Since LED APIs do not require it to be
bumped by the user, drop the reference after LED registration.

[andy: rewritten the commit message and amended the change]

Fixes: c223d9c636ed ("auxdisplay: ht16k33: Add LED support")
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Pull backlight updates from Lee Jones:
 "Fix-ups:
   - FB Backlight interaction overhaul
   - Remove superfluous code and simplify overall
   - Constify various structs and struct attributes

  Bug Fixes:
   - Repair LED flickering
   - Fix signedness bugs"

* tag 'backlight-next-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight: (42 commits)
  backlight: sky81452-backlight: Remove unnecessary call to of_node_get()
  backlight: mp3309c: Fix LEDs flickering in PWM mode
  backlight: otm3225a: Drop driver owner assignment
  backlight: lp8788: Drop support for platform data
  backlight: lcd: Make lcd_class constant
  backlight: Make backlight_class constant
  backlight: mp3309c: Fix signedness bug in mp3309c_parse_fwnode()
  const_structs.checkpatch: add lcd_ops
  fbdev: omap: lcd_ams_delta: Constify lcd_ops
  fbdev: imx: Constify lcd_ops
  fbdev: clps711x: Constify lcd_ops
  HID: picoLCD: Constify lcd_ops
  backlight: tdo24m: Constify lcd_ops
  backlight: platform_lcd: Constify lcd_ops
  backlight: otm3225a: Constify lcd_ops
  backlight: ltv350qv: Constify lcd_ops
  backlight: lms501kf03: Constify lcd_ops
  backlight: lms283gf05: Constify lcd_ops
  backlight: l4f00242t03: Constify lcd_ops
  backlight: jornada720_lcd: Constify lcd_ops
  ...

When CONFIG_PANEL_BOOT_MESSAGE=y the module still includes
the generated header and gets rebuilt even if it doesn't use
anything from that header.  Include generated header conditionally
to avoid unnecessary rebuilds.

Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

The modpost script is not happy

  WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/auxdisplay/charlcd.o

because there is a missing module description.

Add it to the module.

Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

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() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

For better usability group the display drivers together in Kconfig.
With this we will have the following sections:
  - Character LCD
  - Samsung KS0108 LCD controller
  - Single character line display
  - Character LCD with non-conforming interface

Keep Makefile entries sorted alphabetically.

While at it, drop redundant 'default n' entries.

Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Replace the use of struct backlight_properties.fb_blank with a call
to backlight_get_brightness(). The helper implements similar logic
as the driver's function. It also accounts for BL_CORE_SUSPENDED for
drivers that set BL_CORE_SUSPENDRESUME. Ht16k33 doesn't use this, so
there's no change in behaviour here.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Robin van der Gracht <robin@protonic.nl>
Cc: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Robin van der Gracht <robin@protonic.nl>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/20240319093915.31778-2-tzimmermann@suse.de
Signed-off-by: Lee Jones <lee@kernel.org>

The driver sets struct fb_info.bl_dev to the correct backlight
device. Thus rely on the backlight core code to match backlight
and framebuffer devices, and remove the extra check_fb() function
from struct backlight_ops.

v3:
	* use 'check_fb()' in commit message (Andy)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Robin van der Gracht <robin@protonic.nl>
Acked-by: Robin van der Gracht <robin@protonic.nl>
Acked-by: Andy Shevchenko <andy@kernel.org>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20240305162425.23845-3-tzimmermann@suse.de
Signed-off-by: Lee Jones <lee@kernel.org>

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() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>