Convert the GPIO based driver to the new GPIO API. (Only the
gpio_configure() call is affected).
Move configuration to DT where appropriate for both SPI and GPIO
drivers, only leaving the SPI vs. GPIO decision in Kconfig (in
addition to the basic enable for the driver.) Move some files around
to clean up as a result of this change.
led_ws2812 sample changes:
- make the pattern easier to look at by emitting less light
- use led_strip alias from DT to get strip device, allocate
appropriate struct led_rgb buffer, etc.
- move the pins around and remove 96b_carbon support (I have no board
to test with)
GPIO driver specific changes:
- str is required to write OUTSET/OUTCLR, not strb. The registers
are word-sized.
- the str[b] registers must all be in r0-r7, so "l" is the correct GCC
inline assembly constraint for both "base" and "pin"
SPI driver specific changes:
- match the GPIO driver in not supporting the update_channels API
method, which never made sense for this type of strip
- return -ENOMEM when the user tries to send more pixel data
than we have buffer space for instead of -EINVAL
Signed-off-by: Martí Bolívar <marti.bolivar@nordicsemi.no>
Use this short header style in all Kconfig files:
# <description>
# <copyright>
# <license>
...
Also change all <description>s from
# Kconfig[.extension] - Foo-related options
to just
# Foo-related options
It's clear enough that it's about Kconfig.
The <description> cleanup was done with this command, along with some
manual cleanup (big letter at the start, etc.)
git ls-files '*Kconfig*' | \
xargs sed -i -E '1 s/#\s*Kconfig[\w.-]*\s*-\s*/# /'
Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
Clean up space errors and use a consistent style throughout the Kconfig
files. This makes reading the Kconfig files more distraction-free, helps
with grepping, and encourages the same style getting copied around
everywhere (meaning another pass hopefully won't be needed).
Go for the most common style:
- Indent properties with a single tab, including for choices.
Properties on choices work exactly the same syntactically as
properties on symbols, so not sure how the no-indentation thing
happened.
- Indent help texts with a tab followed by two spaces
- Put a space between 'config' and the symbol name, not a tab. This
also helps when grepping for definitions.
- Do '# A comment' instead of '#A comment'
I tweaked Kconfiglib a bit to find most of the stuff.
Some help texts were reflowed to 79 columns with 'gq' in Vim as well,
though not all, because I was afraid I'd accidentally mess up
formatting.
Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
Bool symbols implicitly default to 'n'.
A 'default n' can make sense e.g. in a Kconfig.defconfig file, if you
want to override a 'default y' on the base definition of the symbol. It
isn't used like that on any of these symbols though, and is
inconsistent.
This will make the auto-generated Kconfig documentation have "No
defaults. Implicitly defaults to n." as well, which is clearer than
'default n if ...'
Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
This driver uses a bit-banging based technique of generating a signal
for the WS2812B LED strip. Since bit-banging is very timing sensitive,
where each CPU cycle counts, the driver uses inline assembly to
perform the most critical operataions. This initial version of the
driver only supports a Cortex-M0 implementation, and can e.g. be used
with the ZIP Halo LED strip for the BBC microbit:
https://www.kitronik.co.uk/5625-zip-halo-for-the-bbc-microbit.html
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The APA102 is a RGB LED with integrated controller. LEDs can be
daisy-chained and use SPI for communication. The SPI port is
configured via Device Tree.
Tested on the Adafruit Trinket M0.
Signed-off-by: Michael Hope <mlhx@google.com>
The WS2812 LED driver IC has a one-wire interface which encodes bit
values as pulse widths.
The ICs themselves are basically shift registers. Roughly speaking, a
"short" pulse shifts in a zero bit, a "long" pulse shifts in a one
bit, and an inter-pulse gap exceeding a reset time threshold causes a
pixel to latch the shifted-in color values. Each chip has an output
pin for daisy chaining. Refer to the chip datsheets and comments in
Kconfig.ws2812 for more details.
To meet timing without hogging the core, this driver generates pulses
using SPI. To work, this requires the MOSI line to stay low between
SPI frames, and for inter-frame delays to be less than the reset pulse
time.
There are other ways do it (PWM + DMA on some SoCs, GPIO bit-banging
if no other tasks need the core), but this is a reasonably
general-purpose implementation.
Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>
LPD880x (e.g. LPD8803, LPD8806) devices are LED driver ICs which can
be controlled via a reduced SPI interface (clock and data only), and
support daisy chaining.
Add an led_strip driver for these devices.
Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>
This API covers drivers for strips, or strings, of individually
addressable LEDs. Both RGB and grayscale LED strip drivers can be
implemented within these APIs.
The API only provides for updating the entire strip, since not all
strips support updating individual LEDs without affecting the others.
Subsequent patches will add individual driver support.
Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>
Martí Bolívar