Construct UART Data Frame with Parity Bit

Code

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

typedef struct {
    uint8_t parity_enable : 1;
    uint8_t parity_type   : 1;
    uint8_t reserved      : 6;
} UART_Control;

uint8_t count_ones(uint8_t data){
    uint8_t count = 0;
    while(data){
        if(data & 0x01) count++;
        data >>= 1;
    }
    return count;
}

uint8_t create_uart_frame(uint8_t data, UART_Control *ctrl) {
    uint8_t frame = data;
    // printf("frame(0): %x\n", frame);
    // printf("parity_enable: %d\n", ctrl->parity_enable);
    // printf("parity_type: %d\n", ctrl->parity_type);
    if(ctrl->parity_enable){
        uint8_t parity = count_ones(data) << 7;
        if(!ctrl->parity_type){
            frame |= parity;
        }
        else{
            frame |= 0b10000000 ^ parity;
        }
    }
    return frame;
}

int main() {
    uint8_t data;
    scanf("%hhu", &data);  // 7-bit input

    uint8_t parity_enable, parity_type;
    scanf("%hhu %hhu", &parity_enable, &parity_type);

    UART_Control ctrl;
    ctrl.parity_enable = parity_enable;
    ctrl.parity_type = parity_type;

    uint8_t frame = create_uart_frame(data, &ctrl);
    printf("frame = 0x%02X", frame);

    return 0;
}

Solving Approach