linux-stable.git/drivers/video/backlight, branch v5.12.2

Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm

2021-02-22T22:27:07+00:00

Pull ARM updates from Russell King:

 - Generalise byte swapping assembly

 - Update debug addresses for STI

 - Validate start of physical memory with DTB

 - Do not clear SCTLR.nTLSMD in decompressor

 - amba/locomo/sa1111 devices remove method return type is void

 - address markers for KASAN in page table dump

* tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: 9065/1: OABI compat: fix build when EPOLL is not enabled
  ARM: 9055/1: mailbox: arm_mhuv2: make remove callback return void
  amba: Make use of bus_type functions
  amba: Make the remove callback return void
  vfio: platform: simplify device removal
  amba: reorder functions
  amba: Fix resource leak for drivers without .remove
  ARM: 9054/1: arch/arm/mm/mmu.c: Remove duplicate header
  ARM: 9053/1: arm/mm/ptdump:Add address markers for KASAN regions
  ARM: 9051/1: vdso: remove unneded extra-y addition
  ARM: 9050/1: Kconfig: Select ARCH_HAVE_NMI_SAFE_CMPXCHG where possible
  ARM: 9049/1: locomo: make locomo bus's remove callback return void
  ARM: 9048/1: sa1111: make sa1111 bus's remove callback return void
  ARM: 9047/1: smp: remove unused variable
  ARM: 9046/1: decompressor: Do not clear SCTLR.nTLSMD for ARMv7+ cores
  ARM: 9045/1: uncompress: Validate start of physical memory against passed DTB
  ARM: 9042/1: debug: no uncompress debugging while semihosting
  ARM: 9041/1: sti LL_UART: add STiH418 SBC UART0 support
  ARM: 9040/1: use DEBUG_UART_PHYS and DEBUG_UART_VIRT for sti LL_UART
  ARM: 9039/1: assembler: generalize byte swapping macro into rev_l

backlight/video: Use Platform getter/setter functions

2021-02-12T10:01:45+00:00

Use getter and setter functions, for platform_device structures and a
spi_device structure.

Signed-off-by: Julia Lawall 
Acked-by: Daniel Vetter 
Signed-off-by: Lee Jones

backlight: ktd253: Bring up in a known state

2021-02-09T14:09:21+00:00

The KTD253 backlight might already be on when the driver
is probed: then we don't really know what the current
ratio is and all light intensity settings will be off
relative to what it was at boot.

To fix this, bring up the backlight OFF then move it to
the default backlight from there so we know the state.

Signed-off-by: Linus Walleij 
Reviewed-by: Daniel Thompson 
Signed-off-by: Lee Jones

ARM: 9049/1: locomo: make locomo bus's remove callback return void

2021-02-01T19:44:30+00:00

The driver core ignores the return value of struct bus_type::remove
because there is only little that can be done. To simplify the quest to
make this function return void, let struct locomo_driver::remove return
void, too. All users already unconditionally return 0, this commit makes
it obvious that returning an error code is a bad idea and ensures future
users behave accordingly.

Link: https://lore.kernel.org/r/20201126110140.2021758-1-u.kleine-koenig@pengutronix.de

Acked-by: Dmitry Torokhov 
Acked-by: Lee Jones 
Signed-off-by: Uwe Kleine-König 
Signed-off-by: Russell King

backlight: sky81452-backlight: Convert comma to semicolon

2021-01-20T12:54:14+00:00

Replace a comma between expression statements by a semicolon.

Signed-off-by: Zheng Yongjun 
Reviewed-by: Daniel Thompson 
Signed-off-by: Lee Jones

backlight: lms283gf05: Convert to GPIO descriptors

2021-01-20T12:47:11+00:00

This converts the lms283gf05 backlight driver to use GPIO
descriptors and switches the single PXA Palm Z2 device
over to defining these.

Since the platform data was only used to convey GPIO
information we can delete the platform data header.

Notice that we define the proper active low semantics in
the board file GPIO descriptor table (active low) and
assert the reset line by bringing it to "1" (asserted).

Cc: Marek Vasut 
Cc: Haojian Zhuang 
Cc: Robert Jarzmik 
Signed-off-by: Linus Walleij 
Reviewed-by: Daniel Mack 
Acked-by: Mark Brown 
Reviewed-by: Daniel Thompson 
Signed-off-by: Lee Jones

backlight: pwm_bl: Fix interpolation

2020-11-04T15:54:57+00:00

The previous behavior was a little unexpected, its properties/problems:
1. It was designed to generate strictly increasing values (no repeats)
2. It had quantization errors when calculating step size. Resulting in
unexpected jumps near the end of some segments.

Example settings:
	brightness-levels = <0 1 2 4 8 16 32 64 128 256>;
	num-interpolated-steps = <16>;

Whenever num-interpolated-steps was larger than the distance
between 2 consecutive brightness levels the table would get really
discontinuous. The slope of the interpolation would stick with
integers only and if it was 0 the whole line segment would get skipped.

The distances between 1 2 4 and 8 would be 1 (property #1 fighting us),
and only starting with 16 it would start to interpolate properly.

Property #1 is not enough. The goal here is more than just monotonically
increasing. We should still care about the shape of the curve. Repeated
points might be desired if we're in the part of the curve where we want
to go slow (aka slope near 0).

Problem #2 is plainly a bug. Imagine if the 64 entry was 63 instead,
the calculated slope on the 32-63 segment will be almost half as it
should be.

The most expected and simplest algorithm for interpolation is linear
interpolation, which would handle both problems.
Let's just implement that!

Take pairs of points from the brightness-levels array and linearly
interpolate between them. On the X axis (what userspace sees) we'll
now have equally sized intervals (num-interpolated-steps sized,
as opposed to before where we were at the mercy of quantization).

Signed-off-by: Alexandru Stan 
Reviewed-by: Daniel Thompson 
Signed-off-by: Lee Jones

Merge tag 'backlight-next-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight

2020-10-14T22:59:42+00:00

Pull backlight updates from Lee Jones:
 "New Drivers:
   - Add support for KTD253

  Fix-ups:
   - Add Device Tree documentation; common, kinetic,ktd253
   - Use correct header(s); tosa_lcd, tosa_bl

  Bug Fixes:
   - Fix refcount imbalance; sky81452-backlight"

* tag 'backlight-next-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight:
  backlight: tosa_bl: Include the right header
  backlight: tosa_lcd: Include the right header
  backlight: Add Kinetic KTD253 backlight driver
  dt-bindings: backlight: Add Kinetic KTD253 bindings
  dt-bindings: backlight: Add some common backlight properties
  backlight: sky81452-backlight: Fix refcount imbalance on error

backlight: tosa_bl: Include the right header

2020-09-08T11:31:19+00:00

The Tosa backlight driver was converted to use GPIO descriptors
in 0b0cb52bd80eda76c4b9921f5cf9c1b709d44e83
("video: backlight: tosa: Use GPIO lookup table") but
still includes  rather than .
Fix it.

Cc: Arnd Bergmann 
Cc: Robert Jarzmik 
Signed-off-by: Linus Walleij 
Reviewed-by: Daniel Thompson 
Signed-off-by: Lee Jones

backlight: tosa_lcd: Include the right header

2020-09-08T11:30:02+00:00

The Tosa backlight LCDE driver was converted to use GPIO descriptors
in 0b0cb52bd80eda76c4b9921f5cf9c1b709d44e83
("video: backlight: tosa: Use GPIO lookup table") but
still includes  rather than .
Fix it.

Cc: Arnd Bergmann 
Cc: Robert Jarzmik 
Signed-off-by: Linus Walleij 
Reviewed-by: Daniel Thompson 
Signed-off-by: Lee Jones