src/port.c


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#include "port.h"

void port_write(struct port p, uint32_t data) {
	switch (p.bandwidth) {
		case port8bit:
			asm volatile("outb %0, %1" : : "a" ((uint8_t) data), "Nd" (p.port_number));
			break;
		case port8bit_slow:
			asm volatile("outb %0, %1\njmp 1f\n1: jmp 1f\n1:" : 
					: "a" ((uint8_t) data), "Nd" (p.port_number));
			break;
		case port16bit:
			asm volatile("outw %0, %1" : : "a" ((uint16_t) data), "Nd" (p.port_number));
		case port32bit:
			asm volatile("outl %0, %1" : : "a" (data), "Nd" (p.port_number));
			break;
	}
}

uint32_t port_read(struct port p) {
	uint32_t result = 0;
	switch (p.bandwidth) {
	 	case port8bit:
			asm volatile("inb %1, %0" : "=a" (result) : "Nd" (p.port_number));
			break;
		case port8bit_slow:
			asm volatile("inb %1, %0\njmp 1f\n1: jmp 1f\n1:" : "=a" (result) : "Nd" (p.port_number));
			break;
		case port16bit:
			asm volatile("inw %1, %0" : "=a" (result) : "Nd" (p.port_number));
			break;
		case port32bit:
			asm volatile("inl %1, %0" : "=a" (result) : "Nd" (p.port_number));
	}

	return result;
}