diff --git a/driver/irq/pic/serial/serial.c b/driver/irq/pic/serial/serial.c new file mode 100644 index 0000000..2f9e399 --- /dev/null +++ b/driver/irq/pic/serial/serial.c @@ -0,0 +1,55 @@ + +#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) { + 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++; + } + } + } +} diff --git a/driver/irq/pic/serial/serial.h b/driver/irq/pic/serial/serial.h new file mode 100644 index 0000000..612bb7a --- /dev/null +++ b/driver/irq/pic/serial/serial.h @@ -0,0 +1,33 @@ +#pragma once + +#include "stdbool.h" + +#ifdef __cplusplus +extern "C" { +#endif + + +// Serial port state. +// +// Line protocol defaults to 8N1 (8 bits, no parity, one stop bit) +typedef struct { + int port; // IO Port + bool ok; // Is the port usable? +} pic_serial_Port; + +extern pic_serial_Port pic_serial_COM1, pic_serial_COM2; + +// Init initializes a serial port. Returns true if success. +// +// TODO lineFlags is ignored by now, always 8N1 +bool pic_serial_Init(pic_serial_Port *port, int baudrate, int lineFlags); + +// Write writes a string to a serial port, if the port is usable. +// +// Writes n chars. If n is 0, writes until it reaches NUL. +void pic_serial_Write(pic_serial_Port *port, const char *str, int n); + + +#ifdef __cplusplus +} +#endif