root@00000000_T1:/tmp/ch35_38x/driver$ make
make -C /lib/modules/4.18.14-1.el7.elrepo.x86_64/build SUBDIRS=/tmp/ch35_38x/driver modules
make[1]: Entering directory `/usr/src/kernels/4.18.14-1.el7.elrepo.x86_64'
  CC [M]  /tmp/ch35_38x/driver/wch_serial.o
/tmp/ch35_38x/driver/wch_serial.c: In function ‘wch_ser_register_ports’:
/tmp/ch35_38x/driver/wch_serial.c:3676:13: error: implicit declaration of function ‘init_timer’ [-Werror=implicit-function-declaration]
             init_timer(&sp->timer);
             ^
/tmp/ch35_38x/driver/wch_serial.c:3678:32: warning: assignment from incompatible pointer type [enabled by default]
             sp->timer.function = wch_ser_timeout;
                                ^
/tmp/ch35_38x/driver/wch_serial.c: At top level:
/tmp/ch35_38x/driver/wch_serial.c:1336:1: warning: ‘ser_get_lsr_info’ defined but not used [-Wunused-function]
 ser_get_lsr_info(
 ^
cc1: some warnings being treated as errors
make[2]: *** [/tmp/ch35_38x/driver/wch_serial.o] Error 1
make[1]: *** [_module_/tmp/ch35_38x/driver] Error 2
make[1]: Leaving directory `/usr/src/kernels/4.18.14-1.el7.elrepo.x86_64'
make: *** [modules] Error 2