Compilation error on RPI 4 (incompatible-pointer-types)

[d1ckb31n]

Any idea on how to fix this compilation error on a RPI4?

pi@raspberrypi:~/soft_uart $ make
make -C /usr/src/linux-headers-6.6.20+rpt-rpi-v8 M=/home/pi/soft_uart modules
make[1]: Entering directory '/usr/src/linux-headers-6.6.20+rpt-rpi-v8'
CC [M] /home/pi/soft_uart/module.o
/home/pi/soft_uart/module.c:47:22: error: initialization of ‘ssize_t (*)(struct tty_struct *, const u8 , size_t)’ {aka ‘long int ()(struct tty_struct *, const unsigned char , long unsigned int)’} from incompatible pointer type ‘int ()(struct tty_struct *, const unsigned char , int)’ [-Werror=incompatible-pointer-types]
47 | .write = soft_uart_write,
| ^~~~~~~~~~~~~~~
/home/pi/soft_uart/module.c:47:22: note: (near initialization for ‘soft_uart_operations.write’)
/home/pi/soft_uart/module.c:52:22: error: initialization of ‘void ()(struct tty_struct *, const struct ktermios )’ from incompatible pointer type ‘void ()(struct tty_struct *, struct ktermios *)’ [-Werror=incompatible-pointer-types]
52 | .set_termios = soft_uart_set_termios,
| ^~~~~~~~~~~~~~~~~~~~~
/home/pi/soft_uart/module.c:52:22: note: (near initialization for ‘soft_uart_operations.set_termios’)
cc1: some warnings being treated as errors
make[3]: *** [/usr/src/linux-headers-6.6.20+rpt-common-rpi/scripts/Makefile.build:248: /home/pi/soft_uart/module.o] Error 1
make[2]: *** [/usr/src/linux-headers-6.6.20+rpt-common-rpi/Makefile:1938: /home/pi/soft_uart] Error 2
make[1]: *** [/usr/src/linux-headers-6.6.20+rpt-common-rpi/Makefile:246: __sub-make] Error 2
make[1]: Leaving directory '/usr/src/linux-headers-6.6.20+rpt-rpi-v8'
make: *** [Makefile:9: all] Error 2
pi@raspberrypi:~/soft_uart $

[bibiboss]

Same here on RPI5

[Prafulcoder]

open module.c file ... replace static void soft_uart_set_termios(struct tty_struct*, struct ktermios*); with static void soft_uart_set_termios(struct tty_struct*,const struct ktermios*); in both function definition and derivation ..

[gseqBE]

Added fixes and PR here: #32

[jerrygeo]

On RPI 3b, Raspian GNU/Linux 13 (trixie) after fix of Prafulcoder Oct 30, 2024, compile fails with:
make[1]: Entering directory '/usr/src/linux-headers-6.12.47+rpt-rpi-v7'

ERROR: modpost: "gpio_set_debounce" [/home/pi/workspace/soft_uart/soft_uart.ko] undefined!
make[3]: *** [/usr/src/linux-headers-6.12.47+rpt-common-rpi/scripts/Makefile.modpost:145: /home/pi/workspace/soft_uart/Module.symvers] Error 1