This version (24 Jul 2020 11:05) was approved by Sunny Feng.The Previously approved version (03 Jul 2020 05:16) is available.
Table of Contents
Linux LCD device driver
Introduction
This section describes the steps required to build and use LCD device driver on Linux using an ADSP-SC58x board and a WVGA/LCD EI3 extender board.
WVGA/LCD EI3 Extender LCD board is not supported on the ADSP-SC573 EZ-KIT due to some board level hardawre confilict, the SC573 processor itself is capable of doing this.
Hardware Setup
- ADSP-SC58x EZ-KIT: ADSP-SC589/SC584 EZ-Board
- A WVGA/LCD EI3 Extender Board
Connect the J1 connector on the LCD EI3 Extender Board to the P1A connector on the SC58x-EZKIT
Software Configuration
The following configuration should be done on top of the sc589-ezkit/sc584-ezkit default configuration.
Configure Linux Kernel
Run bitbake linux-adi -c menuconfig and configure the kernel as follows:
Enable touchscreen and backlight
Device Drivers --->
Input device support --->
[*] Touchscreens --->
<*> Analog Devices AD7879-1/AD7889-1 touchscreen interface
<*> support SPI bus connection
Enable NL8048HL WVGA LCD for ADSP-SC58x
Device Drivers --->
Graphics support --->
Frame buffer Devices --->
<*> Support for frame buffer devices --->
<*> NEC NL8048HL WVGA LCD for ADI SC5XX boards
Avoid LCD driver probe failure by disabling CAN bus support
[*] Networking support --->
< > CAN bus subsystem support ----
Enable Packages
Add the video test program in the filesystem images, it's default enabled in adsp-sc5xx-full image.
vim build/conf/local.conf IMAGE_INSTALL_append = "video-test"
Example
Enable LCD Back-light
# cat /sys/kernel/debug/gpio mcp230xx 0-0022: restoring reg 0x00 from 0x0000 to 0xffff (power-loss?) mcp230xx 0-0021: restoring reg 0x00 from 0x0000 to 0xffff (power-loss?) gpiochip0: GPIOs 0-15, adi-gpio: gpiochip1: GPIOs 16-31, adi-gpio: gpio-30 ( |mdio-reset ) out hi gpiochip2: GPIOs 32-47, adi-gpio: gpio-32 ( |spi0.32 ) out hi gpio-39 ( |spi0.39 ) out hi gpio-44 ( |spi0.44 ) out hi gpiochip3: GPIOs 48-63, adi-gpio: gpiochip4: GPIOs 64-79, adi-gpio: gpiochip5: GPIOs 80-95, adi-gpio: gpiochip6: GPIOs 96-101, adi-gpio: gpiochip9: GPIOs 479-479, parent: spi/spi0.32, AD7879-GPIO, can sleep: gpiochip8: GPIOs 480-495, parent: i2c/0-0022, mcp23017, can sleep: gpiochip7: GPIOs 496-511, parent: i2c/0-0021, mcp23017, can sleep: # echo 479 > /sys/class/gpio/export # echo high > /sys/class/gpio/gpio479/direction
Make sure your LCD screen becomes white at this point.
Soft Switch Configuration
The settings in this section is only apply to ADSP-SC584 EZ-Board.
# echo 484 > /sys/class/gpio/export # echo high > /sys/class/gpio/gpio484/direction # echo 491 > /sys/class/gpio/export # echo high > /sys/class/gpio/gpio491/direction
Run video_test Program
You will see a crossing curve like an “8” in the LCD window.
# video_test
How to Install Modules
Select these drivers as modules:
<M> Analog Devices AD7879-1/AD7889-1 touchscreen interface <M> support SPI bus connection <M> Support for frame buffer devices ---> <M> NEC NL8048HL WVGA LCD for ADI SC5XX boards
Then bitbake adsp-sc5xx-full -C compile
If AD7879 module has already been installed, removed it first:
# lsmod Module Size Used by ad7879_spi 2222 0 ad7879 3763 1 ad7879_spi # modprobe -r ad7879_spi # lsmod Module Size Used by
Then install the modules as follows:
# modprobe adi_nl8048 adi_nl8048 31040000.lcd: LCD fb0 registered@cf15f846,dma=28,irq=48,cs=39 # modprobe ad7879_spi input: AD7879 Touchscreen as /devices/platform/scb/31042000.spi/spi_master/spi0/spi0.32/input/input0
Now you can run LCD test as above.
Back to Kernel Features and Device Drivers for ADSP-SC5xx Yocto Linux
resources/tools-software/linuxdsp/docs/linux-kernel-and-drivers/lcd/lcd_display.txt · Last modified: 03 Jul 2020 09:04 by Sunny Feng