Set Specific Bits in a 32-bit Register

Code

#include <stdio.h>
#include <stdint.h>

uint32_t set_bits(uint32_t reg, uint8_t pos, uint8_t len) {
    uint8_t i,n;
    for(i=1;i<=len;i++){
    n= pos+len-i;
    reg|=(1<<n);
    //i++;
    }
    return reg;
}

int main() {
    uint32_t reg;
    uint8_t pos, len,n;
    scanf("%u %hhu %hhu", &reg, &pos, &len);
    printf("%u", set_bits(reg, pos, len));
    return 0;
}

Solving Approach