mcuee@raspberrypi400arm64:~/build/avrdude_sr/build_linux/src $ ./avrdude -p m328p -c linuxspi -P /dev/spidev0.0:/dev/gpiochip0:25 -v
Avrdude version 8.0-20250106 (713241f9)
Copyright see https://github.com/avrdudes/avrdude/blob/main/AUTHORS

System wide configuration file is /home/mcuee/build/avrdude_sr/build_linux/src/avrdude.conf
User configuration file is /home/mcuee/.avrduderc

Using port            : /dev/spidev0.0:/dev/gpiochip0:25
Using programmer      : linuxspi
Defaulting bit clock to 200 kHz
AVR part              : ATmega328P
Programming modes     : SPM, ISP, HVPP, debugWIRE
Programmer type       : linuxspi
Description           : Use Linux SPI device in /dev/spidev*

AVR device initialized and ready to accept instructions
Device signature = 1E 95 0F (ATmega328P, ATA6614Q, LGT8F328P)

Avrdude done.  Thank you.

mcuee@raspberrypi400arm64:~/build/avrdude_sr/tools $ ./test-avrdude -e ../build_linux/src/avrdude -c ../build_linux/src/avrdude.conf -p "-p m328p -c linuxspi -P /dev/spidev0.0:/dev/gpiochip0:25"
Testing ../build_linux/src/avrdude 8.0-20250106 (713241f9)
Prepare "-p m328p -c linuxspi -P /dev/spidev0.0:/dev/gpiochip0:25" and press 'enter' or 'space' to continue. Press any other key to skip
✅   0.384 s: fuse access: clear, set and read eesave fuse bit
✅   0.287 s: fuse access: set eesave fusebit to delete EEPROM on chip erase
✅   0.340 s: chip erase
✅   2.642 s: flash -U write/verify holes_rjmp_loops_32768B.hex
✅   2.488 s: flash -T write/verify holes_rjmp_loops_32768B.hex
✅   0.306 s: eeprom check whether programmer can flip 0s to 1s
✅   1.358 s: eeprom -U write/verify holes_pack_my_box_1024B.hex
✅   2.316 s: eeprom -T write/verify holes_{the_five_boxing_wizards,pack_my_box}_1024B.hex
✅   1.458 s: chip erase and spot check flash is actually erased
✅   0.346 s: spot check eeprom is erased, too