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rpi wavecomm
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‎rpi/wavecom35a-3.5-lcd/notes

+99-105
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downloaded LCD_show
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read script LCD35-show
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https://gist.github.com/notro/63fc8f563b5f85010d30
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installed pkgs (some may be present)
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"gpio" command ! woah
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sudo apt-get install xserver-xorg-input-evdev xinput-calibrator xserver-xorg-video-fbdev fbset
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SPEC https://www.waveshare.com/wiki/3.5inch_RPi_LCD_(A)
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copied device tree overlays from lcd-show
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https://elinux.org/Device_Tree_Source_Undocumented
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sudo cp ./waveshare35a-overlay.dtb /boot/overlays/waveshare35a.dtbo
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sudo cp ./waveshare35a-overlay.dtb /boot/overlays/
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https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git/tree/drivers/staging/fbtft/README?h=staging-testing
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https://github.com/notro/fbtft/wiki/Device-Tree
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https://github.com/notro/fbtft/wiki/FBTFT-RPI-overlay
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added to cmdline.txt
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fbcon=map:10 fbcon=font:ProFont6x11
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https://www.kernel.org/doc/Documentation/devicetree/bindings/spi/
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https://www.kernel.org/doc/Documentation/devicetree/bindings/spi/spi-controller.yaml
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modified config.txt (unsure yet if all mods needed)
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controller is https://www.kernel.org/doc/Documentation/devicetree/bindings/pinctrl/brcm%2Cbcm2835-gpio.txt
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dtparam=i2c_arm=on
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dtparam=spi=on
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enable_uart=1
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https://www.kernel.org/doc/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
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dtoverlay=waveshare35a
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#dtoverlay=ads7846,cs=1,penirq=17,penirq_pull=2,speed=1000000,keep_vref_on=1,swapxy=1,pmax=255,xohms=60,xmin=200,xmax=3900,ymin=200,ymax=3900
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hdmi_force_hotplug=1
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hdmi_group=2
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hdmi_mode=1
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hdmi_mode=87
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hdmi_cvt 480 320 60 6 0 0 0
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hdmi_drive=2
23+
AHA! the documented pinout like https://www.waveshare.com/3.5inch-rpi-lcd-a.htm is the rPi physical pinout. The device-tree config uses the GPIO numbers like https://www.researchgate.net/figure/Schematic-zoom-of-the-Raspberry-Pi-3-B-pins-Adapted-from-14_fig2_351755761
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docs:
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con2fbmap
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chvt
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on fbcon, fbcon=map option etc:
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* https://www.kernel.org/doc/Documentation/fb/fbcon.txt
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* control after with con2fbmap command
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driver = fb_ili9486 (fbtft based)
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aha, so the trick here is to fake the pi into thinking it has hdmi, output to hdmi, then clone fb0->fb1 in userspace with fbcp, ew. But it's useful to keep the hdmi options
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in config.txt because otherwise the lcd will sometimes be fb0, sometimes fb1.
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created /etc/X11/xorg.conf.d/
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# lock cpu freq
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for f in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor; do
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echo 'performance' | sudo tee -a $f;
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done
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for f in /sys/devices/system/cpu/cpu*/cpufreq/{scaling_min_freq,scaling_max_freq}; do
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echo '500000' | sudo tee -a $f;
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done
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created /etc/X11/xorg.conf.d/99-fbdev-lcd.conf
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cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_cur_freq
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Section "Device"
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Identifier "lcd35"
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Driver "fbdev"
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Option "fbdev" "/dev/fb1"
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EndSection
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cat /sys/kernel/debug/clk/clk_summary
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https://starfishmedical.com/blog/raspberry-pi-clock-conundrum/
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(may need to change)
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/etc/init.d/lightdm restart
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try dtparam uart1 on / off ?
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... with which the display blanks, but doesn't do anything else, damn.
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vcgencmd get_config str
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made it work with a more complex x config; may break after reboot hdmi
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# Note that this supplements the default config loaded from
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# /etc/X11/xorg.conf.d/99-fbdev-lcd.conf and the other .conf files there.
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# tis doesn't seem right
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#
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# I actually observe somewhat working with reset 0x19 (25), dc 0x18 (24), pendown 0x11 (17)
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# which is wtf. Data pin must be right if display can show stuff.
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#
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# but all refs agree https://www.waveshare.com/3.5inch-rpi-lcd-a.htm
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#
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Section "Device"
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Identifier "lcd35"
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Driver "fbdev"
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Option "fbdev" "/dev/fb1"
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EndSection
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Section "Monitor"
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Identifier "hdmi"
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EndSection
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LCD panel: Ilitek ILI9486
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Touch layer: ADS7846
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Touch controller: XPT2046
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Section "Monitor"
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Identifier "lcd35"
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VendorName "Wavecomm-clone"
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ModelName "Touch-35"
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# DisplaySize ...
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# Option "Rotate" ...
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EndSection
65+
Pin Symbol Description
66+
1, 17 3.3V + Power rail
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2, 4 5V + Power rail
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3, 5, 7, 8, 10, 12, 13, 15, 16 NV NC
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6, 9, 14, 20, 25 GND Ground
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11 TP_IRQ Touch panel interrupt, pulled low during touch
71+
18 LCD_RS LCD instruction control, Instruction/Data register selection
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19 LCD_SI/TP_SI SPI data input of both LCD & touch panel
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21 TP_S0 SPI data output of touch panel
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22 RST Reset
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23 LCD_SCK/TP_SCK SPI clock for both LCD & touch panel
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24 LCD_CS LCD chip select (active low)
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26 TP_CS Touch panel chip select (active low)
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Section "Screen"
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Identifier "lcd35"
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Device "lcd35"
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Monitor "lcd35"
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EndSection
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# The device is defined in /etc/X11/xorg.conf.d/99-fbdev-lcd.conf
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Section "Screen"
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Identifier "hdmi"
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Device "Allwinner A10/A13 FBDEV"
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Monitor "hdmi"
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EndSection
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/*
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* Pin mapping
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* PHY GPIO NAME INOUT PULL ACTIVE DESC
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* 11 17 TP_IRQ IN H? LOW Touch panel interrupt, pulled low during touch
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* 18 24 LCD_RS OUT LCD instruction control, Instruction/Data register selection
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* 19 10 LCD_SI/TP_SI OUT SPI data input of both LCD & touch panel
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* 21 9 TP_S0 IN SPI data output of touch panel
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* 22 25 RST OUT H? Reset
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* 23 11 LCD_SCK/TP_SCK OUT SPI clock for both LCD & touch panel
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* 24 8 LCD_CS OUT H? LOW LCD chip select (active low)
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* 26 7 TP_CS OUT H? LOW Touch panel chip select (active low)
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*/
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Section "ServerLayout"
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Identifier "lcd35"
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Screen "lcd35"
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Screen "hdmi" RightOf "lcd35"
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#InputDevice "ADS7846 Touchscreen" "SendCoreEvents"
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EndSection
93+
/proc/device-tree/soc/gpio@7e200000/spi0_pins/brcm,pins
94+
0000000 0000 0900 0000 0a00 0000 0b00
95+
0000014
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104-
touchscreen rotated. Used
97+
/proc/device-tree/soc/gpio@7e200000/spi0_gpio7/brcm,pins
98+
0000000 0000 0700 0000 0800 0000 0900 0000 0a00
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0000020 0000 0b00
100+
0000024
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sudo DISPLAY=:0 XAUTHORITY=/var/run/lightdm/root/:0 xinput list
102+
/proc/device-tree/soc/gpio@7e200000/alt0/brcm,pins
103+
0000000 0000 0400 0000 0500 0000 0700 0000 0800
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0000020 0000 0900 0000 0a00 0000 0b00
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0000034
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pi@raspberrypi:~ $ sudo DISPLAY=:0 XAUTHORITY=/var/run/lightdm/root/:0 xinput list
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⎡ Virtual core pointer id=2 [master pointer (3)]
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⎜ ↳ Virtual core XTEST pointer id=4 [slave pointer (2)]
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⎜ ↳ ADS7846 Touchscreen id=6 [slave pointer (2)]
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⎣ Virtual core keyboard id=3 [master keyboard (2)]
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↳ Virtual core XTEST keyboard id=5 [slave keyboard (3)]
108+
what about using spi0-2cs ?
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craig@raspberrypi:~ $ sudo dtoverlay -h spi0-2cs
111+
Name: spi0-2cs
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then ran
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Info: Change the CS pins for SPI0
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sudo DISPLAY=:0 XAUTHORITY=/var/run/lightdm/root/:0 xinput_calibrator
115+
Usage: dtoverlay=spi0-2cs,<param>=<val>
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121-
to get
117+
Params: cs0_pin GPIO pin for CS0 (default 8)
118+
cs1_pin GPIO pin for CS1 (default 7)
119+
no_miso Don't claim and use the MISO pin (9), freeing
120+
it for other uses.
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Section "InputClass"
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Identifier "calibration"
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MatchProduct "ADS7846 Touchscreen"
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Option "MinX" "20980"
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Option "MaxX" "22437"
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Option "MinY" "50226"
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Option "MaxY" "52274"
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Option "SwapXY" "1" # unless it was already set to 1
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Option "InvertX" "0" # unless it was already set
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Option "InvertY" "0" # unless it was already set
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EndSection
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installed in config as simplified
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https://raspberrypi.stackexchange.com/questions/24279/disable-bcm2708-fb-the-hdmi-framebuffer-device
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Section "InputClass"
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Identifier "calibration"
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MatchProduct "ADS7846 Touchscreen"
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Option "SwapXY" "1" # unless it was already set to 1
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Option "InvertX" "0" # unless it was already set
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Option "InvertY" "0" # unless it was already set
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EndSection
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but didn't work because swapxy not working
127+
Looks like it works if I disable the use of /dev/fb0 on /usr/share/X11/xorg.conf.d/99-fbturbo.conf
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If I want both displays to work I have to switch to using fbturbo for the driver on the little panel too,
151-
it doesn't like sharing with fbdev.
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132+
touch is ads7846
133+
but no worky?
134+
[ 788.783946] SPI driver ads7846 has no spi_device_id for ti,tsc2046
135+
[ 788.783979] SPI driver ads7846 has no spi_device_id for ti,ads7843
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[ 788.783992] SPI driver ads7846 has no spi_device_id for ti,ads7845
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[ 788.784003] SPI driver ads7846 has no spi_device_id for ti,ads7873
138+
relevant? why no evdev?
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140+
sudo dtoverlay ads7846 penirq=17 xohms=60 pmax=255
141+
sudo dtoverlay ads7846 cs=1 penirq=17 penirq_pull=2 speed=50000 swapxy=0 pmax=255 xohms=80 xmin=20
142+
143+
144+
someone else's:
145+
dtoverlay=ads7846,cs=1,penirq=25,penirq_pull=2,speed=50000,keep_vref_on=0,swapxy=0,pmax=255,xohms=150,xmin=200,xmax=3900,ymin=200,ymax=3900
146+
147+
https://www.kernel.org/doc/Documentation/devicetree/bindings/input/ads7846.txt

‎rpi/wavecom35a-3.5-lcd/notes-bullseye

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tft35a-overlay-hacked.dts

‎rpi/wavecom35a-3.5-lcd/99-fbdev-lcd.conf ‎rpi/wavecom35a-3.5-lcd/oldpi/99-fbdev-lcd.conf

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