helos1/driver/irq/pic/serial/serial.c

58 lines
1.7 KiB
C

#include "serial.h"
#include "../internal.h"
#include "../../../../interrupt/interrupt.h"
pic_serial_Port pic_serial_COM1 = {0x3f8, false}, pic_serial_COM2 = {0x2f8, false};
bool pic_serial_Init(pic_serial_Port *port, int baudrate, int lineFlags) {
if (115200 % baudrate != 0)
return false;
uint16_t divisor = 115200 / baudrate;
INTERRUPT_DISABLE;
outb(port->port + 3, 0x80); // Enable DLAB (set baud rate divisor)
outb(port->port + 0, divisor & 0xFF); // Set divisor (lo byte)
outb(port->port + 1, divisor >> 8); // (hi byte)
outb(port->port + 3, 0x03); // 8 bits, no parity, one stop bit
outb(port->port + 2, 0xC7); // Enable FIFO, clear them, with 14-byte threshold
outb(port->port + 4, 0x0B); // IRQs enabled, RTS/DSR set
outb(port->port + 4, 0x1E); // Set in loopback mode, test the serial chip
outb(port->port + 0, 0xAE); // Test serial chip (send byte 0xAE and check if serial returns same byte)
// Check if serial is faulty (i.e: not same byte as sent)
if (inb(port->port + 0) != 0xAE) {
INTERRUPT_RESTORE;
return false;
}
// If serial is not faulty set it in normal operation mode
// (not-loopback with IRQs enabled and OUT#1 and OUT#2 bits enabled)
outb(port->port + 4, 0x0F);
port->ok = true;
INTERRUPT_RESTORE;
return true;
}
void pic_serial_Write(pic_serial_Port *port, const char *str, int n) {
if (port && port->ok) {
INTERRUPT_DISABLE;
if (n != 0) {
for (int i = 0; i < n; i++) {
while ((inb(port->port + 5) & 0x20) == 0) {}
outb(port->port, str[i]);
}
} else {
while (*str != 0) {
while ((inb(port->port + 5) & 0x20) == 0) {}
outb(port->port, *str);
str++;
}
}
INTERRUPT_RESTORE;
}
}