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Message-Id: <20221129140955.137361-1-gch981213@gmail.com>
Date: Tue, 29 Nov 2022 22:09:52 +0800
From: Chuanhong Guo <gch981213@...il.com>
To: linux-leds@...r.kernel.org
Cc: Chuanhong Guo <gch981213@...il.com>, Pavel Machek <pavel@....cz>,
Rob Herring <robh+dt@...nel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
Stanislav Jakubek <stano.jakubek@...il.com>,
Linus Walleij <linus.walleij@...aro.org>,
Shawn Guo <shawnguo@...nel.org>,
Johan Hovold <johan+linaro@...nel.org>,
Bjorn Andersson <andersson@...nel.org>,
Marijn Suijten <marijn.suijten@...ainline.org>,
Sven Schwermer <sven.schwermer@...ruptive-technologies.com>,
devicetree@...r.kernel.org (open list:OPEN FIRMWARE AND FLATTENED
DEVICE TREE BINDINGS), linux-kernel@...r.kernel.org (open list)
Subject: [PATCH 0/3] leds: add driver for SPI driven WorldSemi WS2812B RGB LEDs
This patch adds support for driving a chain of WS2812B LED chips
using SPI bus.
WorldSemi WS2812B is a individually addressable LED chip that
can be chained together and controlled individually using a
single wire. The chip recognize a long pulse as a bit of 1 and
a short pulse as a bit of 0. Host sends a continuous stream
of 24-bits color values, each LED chip takes the first 3 byte
it receives as its color value and passes the leftover bytes to
the next LED on the chain.
This driver simulates this protocol using SPI bus by sending
a long pulse as 3'b110 and a short pulse as 3'b100. The SPI
frequency needs to be 2.105MHz~2.85MHz for the timing to be
correct and the controller needs to transfer all the bytes
continuously.
Chuanhong Guo (3):
dt-bindings: vendor-prefixes: add an entry for WorldSemi
dt-bindings: leds: add dt schema for worldsemi,ws2812b-spi
leds: add driver for SPI driven WorldSemi WS2812B RGB LEDs
.../bindings/leds/worldsemi,ws2812b-spi.yaml | 131 +++++++++++
.../devicetree/bindings/vendor-prefixes.yaml | 2 +
drivers/leds/rgb/Kconfig | 11 +
drivers/leds/rgb/Makefile | 1 +
drivers/leds/rgb/leds-ws2812b-spi.c | 222 ++++++++++++++++++
5 files changed, 367 insertions(+)
create mode 100644 Documentation/devicetree/bindings/leds/worldsemi,ws2812b-spi.yaml
create mode 100644 drivers/leds/rgb/leds-ws2812b-spi.c
--
2.38.1
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