avr atmega32 rgb controller

#include <avr/io.h>
#include <avr/delay.h>

int maxValue(int x) {
    if (x > 255) {
        return 255;
    }

    return x;
}

int minValue(int x) {
    if (x < 0) {
        return 0;
    }

    return x;
}

int main(void) {
    /*
    WGM10, WGM11 - A
    WGM12, WGM13 - B
    */
    TCCR0|=(1<<WGM00)|(1<<WGM01)|(1<<COM01)|(0<<CS02)|(0<<CS01)|(1<<CS00); // 8 bit
    // (1<<COM1A1)|(1<<COM1B1) - 16bit -> 2x8bit
    // fast PWM, ICR1 = TOP
    TCCR1A|=(1<<COM1A1)|(1<<COM1B1)|(1<<WGM11);
    // (0<<CS12)|(0<<CS11)|(1<<CS10) - prescaler 1
    TCCR1B|=(1<<WGM13)|(1<<WGM12)|(0<<CS12)|(0<<CS11)|(1<<CS10);
    ICR1=255;

    DDRB |= (1 << PB3);
    DDRD |= (1 << PD5) | (1 << PD4);
    DDRA = 0x00; // in

    PORTA = 0xFF;

    int r = 255;
    int g = 255;
    int b = 255;

    OCR0 = r;   // PB3, R
    OCR1A = g;  // PD5, G
    OCR1B = b;  // PD4, B

    int constN = 255 / 7;
    int lastButton = 0;

    while (1) {
        if (PINA == lastButton) {
            continue;
        }

        lastButton = PINA;

        switch (PINA) {
            // R
            case 0b11111110:
                r += constN;
                r = maxValue(r);
                OCR0 = r;
                break;
            case 0b11111101:
                r -= constN;
                r = minValue(r);
                OCR0 = r;
                break;

            // G
            case 0b11111011:
                g += constN;
                g = maxValue(g);
                OCR1A = g;
                break;
            case 0b11110111:
                g -= constN;
                g = minValue(g);
                OCR1A = g;
                break;

            // B
            case 0b11101111:
                b += constN;
                b = maxValue(b);
                OCR1B = b;
                break;
            case 0b11011111:
                b -= constN;
                b = minValue(b);
                OCR1B = b;
                break;
        }
    }

    return 0;
}