1.54" LCD Raspberry Pi Zero

1-54inchlcd.dto

/dts-v1/;
/plugin/;

/ {
        compatible = "brcm,bcm2835", "brcm,bcm2708", "brcm,bcm2709";

        fragment@0 {
                target = <&spi0>;
                __overlay__ {
                        status = "okay";

                        spidev@0{
                                status = "disabled";
                        };

                        spidev@1{
                                status = "disabled";
                        };
                };
        };

        fragment@1 {
                target = <&gpio>;
                __overlay__ {
                        pitft_pins: pitft_pins {
                                brcm,pins = <22 27>;
                                brcm,function = <1 1>; /* out */
                                brcm,pull = <0>; /* none */
                        };
                };
        };

        fragment@2 {
                target = <&spi0>;
                __overlay__ {
                        /* needed to avoid dtc warning */
                        #address-cells = <1>;
                        #size-cells = <0>;

                        pitft: pitft@0{
                                compatible = "sitronix,st7789v";
                                reg = <0>;
                                pinctrl-names = "default";
                                pinctrl-0 = <&pitft_pins>;
                                spi-max-frequency = <48000000>;
                                rotate = <270>;
                                width = <240>;
                                height = <240>;
                                fps = <30>;
                                buswidth = <8>;
                                txbuflen = <32768>;
                                custom = <1>;
                                reset-gpios = <&gpio 27 1>;
                                dc-gpios = <&gpio 22 0>;
                                debug = <0>;
                                spi-cpol;
                                spi-cpha;

                                bgr;
                                init = <0x1000011
                                        0x20000ff

                                        0x100003A 0x55
                                        0x10000C0 0x0C
                                        0x1000021
                                        0x1000029
                                        >;
                        };
                };
        };


        __overrides__ {
                speed =   <&pitft>,"spi-max-frequency:0";
                rotate =  <&pitft>,"rotate:0";
                width =   <&pitft>,"width:0";
                height =  <&pitft>,"height:0";
                fps =     <&pitft>,"fps:0";
                debug =   <&pitft>,"debug:0";
        };
};

99-input.rules

#SUBSYSTEM=="input", GROUP="input", MODE="0660"
#KERNEL=="tty[0-9]*", GROUP="tty", MODE="0660"
#KERNEL=="hidraw*", GROUP="input", MODE="0660"
# Needed for permissions set correctly for /dev/input/event* for keyboard input
#SUBSYSTEM=="input", ATTRS{name}=="input/%k", KERNEL=="event*", MODE="0666", ENV{ID_INPUT_KEYBOARD}="1"
#SUBSYSTEM=="input", ATTRS{name}=="gpio_keys", ENV{ID_INPUT_KEYBOARD}="1"

KERNEL=="event*", SUBSYSTEM=="input", GROUP="input", MODE="0660", ENV{ID_INPUT_KEYBOARD}="1"

config.txt

gpu_mem=32
#cma_lwm=16
#cma_hwm=256
dtoverlay=vc4-fkms-v3d,cma-256
initramfs initramfs-linux.img followkernel

#dtoverlay=dwc2
#dtoverlay=1-54inchlcd

# GPIO buttons
dtoverlay=gpio-key,gpio=3,active_low=1,gpio_pull=up,label=center,keycode=28
dtoverlay=gpio-key,gpio=5,active_low=1,gpio_pull=up,label=up,keycode=103
dtoverlay=gpio-key,gpio=16,active_low=1,gpio_pull=up,label=down,keycode=108
dtoverlay=gpio-key,gpio=13,active_low=1,gpio_pull=up,label=left,keycode=105
dtoverlay=gpio-key,gpio=6,active_low=1,gpio_pull=up,label=right,keycode=106
dtoverlay=gpio-key,gpio=12,active_low=1,gpio_pull=up,label=y,keycode=21
dtoverlay=gpio-key,gpio=20,active_low=1,gpio_pull=up,label=b,keycode=48
dtoverlay=gpio-key,gpio=15,active_low=1,gpio_pull=up,label=x,keycode=45
dtoverlay=gpio-key,gpio=21,active_low=1,gpio_pull=up,label=a,keycode=30
dtoverlay=gpio-key,gpio=19,active_low=1,gpio_pull=up,label=start,keycode=14
dtoverlay=gpio-key,gpio=26,active_low=1,gpio_pull=up,label=select,keycode=1
dtoverlay=gpio-key,gpio=23,active_low=1,gpio_pull=up,label=ltrigger,keycode=16
dtoverlay=gpio-key,gpio=14,active_low=1,gpio_pull=up,label=rtrigger,keycode=18

enable_uart=0

hdmi_force_hotplug=1
max_usb_current=1
hdmi_group=2
hdmi_mode=9
hdmi_mode=87
hdmi_cvt 240 240 60 1 0 0 0
hdmi_drive=2

fbcp.service

[Unit]
Description=FB Copy SPI LCD displays
#After=graphical.target
ConditionKernelCommandLine=!fbcp=0
#Requires=graphical.target

[Service]
User=root
PermissionsStartOnly=true
#Environment=HOME=/home/alarm
ExecStart=/home/alarm/fbcp-ili9341/build/fbcp-ili9341
# keep KillMode=process unless there is no good reason to switch to cgroup
KillMode=process
TimeoutStopSec=10
Restart=always
RestartSec=2
StartLimitInterval=0

[Install]
WantedBy=fbcp.target
WantedBy=multi-user.target

Instructions

# Using https://github.com/juj/fbcp-ili9341:
cmake -DST7789VW=ON -DGPIO_TFT_DATA_CONTROL=22 -DGPIO_TFT_RESET_PIN=27 -DUSE_DMA_TRANSFERS=ON -DSPI_BUS_CLOCK_DIVISOR=20 -DDISPLAY_ROTATE_180_DEGREES=ON -DSTATISTICS=0 ..

# (or using Linux kernel driver "sitronix,st7789v"):
cd /boot/overlays
dtc -I dts -O dtb -o  1-54inchlcd.dtbo 1-54inchlcd.dto

sudo usermod -a -G audio,video,input,dialout,plugdev,tty alarm

# Retroarch: ~/.config/retroarch/retroarch.cfg
libretro_directory = "~/.config/retroarch/cores/"
libretro_info_path = "~/.config/retroarch/cores/info"
core_updater_buildbot_cores_url = "http://buildbot.libretro.com/nightly/linux/armhf/latest/"
core_updater_show_experimental_cores = "true"
video_context_driver = "KMS"

retroarch.service

# Explanation: https://unix.stackexchange.com/a/506374

[Unit]
Description=Retroarch
#After=graphical.target
ConditionKernelCommandLine=!retroarch=0
#Requires=graphical.target
Requires=fbcp.service

[Service]
User=alarm
PermissionsStartOnly=true
#Environment=HOME=/home/alarm
ExecStart=/usr/bin/retroarch
# keep KillMode=process unless there is no good reason to switch to cgroup
KillMode=process
TimeoutStopSec=10
Restart=always
RestartSec=2
StartLimitInterval=0

[Install]
WantedBy=retroarch.target
WantedBy=multi-user.target