linux_dsm_epyc7002/drivers
Enric Balletbo i Serra 88ba95bedb backlight: pwm_bl: Compute brightness of LED linearly to human eye
When you want to change the brightness using a PWM signal, one thing you
need to consider is how human perceive the brightness. Human perceive
the brightness change non-linearly, we have better sensitivity at low
luminance than high luminance, so to achieve perceived linear dimming,
the brightness must be matches to the way our eyes behave. The CIE 1931
lightness formula is what actually describes how we perceive light.

This patch computes a default table with the brightness levels filled
with the numbers provided by the CIE 1931 algorithm, the number of the
brightness levels is calculated based on the PWM resolution.

The calculation of the table using the CIE 1931 algorithm is enabled by
default when you do not define the 'brightness-levels' propriety in your
device tree.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2018-07-04 10:31:18 +01:00
..
accessibility
acpi pwm: Changes for v4.18-rc1 2018-06-14 16:25:43 +09:00
amba
android
ata
atm
auxdisplay
base
bcma
block The main piece is a set of libceph changes that revamps how OSD 2018-06-15 07:24:58 +09:00
bluetooth
bus
cdrom
char docs: Fix some broken references 2018-06-15 18:10:01 -03:00
clk docs: Fix some broken references 2018-06-15 18:10:01 -03:00
clocksource
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crypto
dax
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dio
dma fix a series of Documentation/ broken file name references 2018-06-15 18:10:01 -03:00
dma-buf
edac
eisa
extcon
firewire
firmware Merge branch 'akpm' (patches from Andrew) 2018-06-15 08:51:42 +09:00
fmc
fpga
fsi
gpio
gpu Solve a series of broken links for files under Documentation: 2018-06-17 05:25:18 +09:00
hid docs: fix broken references with multiple hints 2018-06-15 18:10:01 -03:00
hsi
hv
hwmon
hwspinlock
hwtracing
i2c Merge branch 'i2c/for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2018-06-14 16:21:46 +09:00
ide
idle
iio
infiniband
input docs: Fix some broken references 2018-06-15 18:10:01 -03:00
iommu
ipack
irqchip
isdn
leds
lightnvm docs: Fix some broken references 2018-06-15 18:10:01 -03:00
macintosh
mailbox
mcb
md docs: Fix some broken references 2018-06-15 18:10:01 -03:00
media Solve a series of broken links for files under Documentation: 2018-06-17 05:25:18 +09:00
memory
memstick
message
mfd Merge branch 'i2c/for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2018-06-14 16:21:46 +09:00
misc Merge branch 'i2c/for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2018-06-14 16:21:46 +09:00
mmc
mtd
mux
net Solve a series of broken links for files under Documentation: 2018-06-17 05:25:18 +09:00
nfc
ntb
nubus
nvdimm
nvme Merge branch 'nvme-4.18' of git://git.infradead.org/nvme into for-linus 2018-06-15 08:11:05 -06:00
nvmem
of
opp
oprofile
parisc
parport docs: Fix some broken references 2018-06-15 18:10:01 -03:00
pci
pcmcia
perf
phy
pinctrl
platform fix a series of Documentation/ broken file name references 2018-06-15 18:10:01 -03:00
pnp
power
powercap
pps
ps3
ptp
pwm pwm: Changes for v4.18-rc1 2018-06-14 16:25:43 +09:00
rapidio
ras
regulator
remoteproc treewide: use PHYS_ADDR_MAX to avoid type casting ULLONG_MAX 2018-06-15 07:55:25 +09:00
reset
rpmsg
rtc
s390
sbus fix a series of Documentation/ broken file name references 2018-06-15 18:10:01 -03:00
scsi SCSI fixes on 20180613 2018-06-14 16:35:32 +09:00
sfi
sh
siox
slimbus
sn
soc treewide: use PHYS_ADDR_MAX to avoid type casting ULLONG_MAX 2018-06-15 07:55:25 +09:00
soundwire docs: Fix more broken references 2018-06-15 18:11:26 -03:00
spi
spmi
ssb
staging media: v4l: fix broken video4linux docs locations 2018-06-15 18:10:01 -03:00
target
tc
tee
thermal
thunderbolt
tty vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
uio
usb vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
uwb
vfio
vhost virtio, vhost: features, fixes 2018-06-16 06:35:02 +09:00
video backlight: pwm_bl: Compute brightness of LED linearly to human eye 2018-07-04 10:31:18 +01:00
virt
virtio virtio, vhost: features, fixes 2018-06-16 06:35:02 +09:00
visorbus
vlynq
vme
w1
watchdog
xen
zorro
Kconfig
Makefile