56 lines
2.0 KiB
C
56 lines
2.0 KiB
C
//
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// Created by rick on 28-01-21.
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//
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#include "serial.h"
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#include <types.h>
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#include <drivers/ports.h>
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int serial_init() {
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port_byte_out(PORT_SERIAL_0 + PORT_SERIAL_INTERRUPT, 0x00); // Disable all interrupts
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port_byte_out(PORT_SERIAL_0 + PORT_SERIAL_LINE_CONTROL, 0x80); // Enable DLAB (set baud rate divisor)
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port_byte_out(PORT_SERIAL_0 + PORT_SERIAL_DLAB_LSB, 0x03); // Set divisor to 3 (lo byte) 38400 baud
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port_byte_out(PORT_SERIAL_0 + PORT_SERIAL_DLAB_MSB, 0x00); // (hi byte)
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port_byte_out(PORT_SERIAL_0 + PORT_SERIAL_LINE_CONTROL, 0x03); // 8 bits, no parity, one stop bit
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port_byte_out(PORT_SERIAL_0 + PORT_SERIAL_INTERRUPT_ID_FIFO,
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0xC7); // Enable FIFO, clear them, with 14-byte threshold
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port_byte_out(PORT_SERIAL_0 + PORT_SERIAL_MODEM_CONTROL, 0x0B); // IRQs enabled, RTS/DSR set
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port_byte_out(PORT_SERIAL_0 + PORT_SERIAL_MODEM_CONTROL, 0x1E); // Set in loopback mode, test the serial chip
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port_byte_out(PORT_SERIAL_0 + PORT_SERIAL_DATA,
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0xAE); // Test serial chip (send byte 0xAE and check if serial returns same byte)
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// Check if serial is faulty (i.e: not same byte as sent)
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if (port_byte_in(PORT_SERIAL_0 + PORT_SERIAL_DATA) != 0xAE) {
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return 1;
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}
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// If serial is not faulty set it in normal operation mode
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// (not-loopback with IRQs enabled and OUT#1 and OUT#2 bits enabled)
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port_byte_out(PORT_SERIAL_0 + PORT_SERIAL_MODEM_CONTROL, 0x0F);
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return 0;
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}
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int is_transmit_empty() {
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return port_byte_in(PORT_SERIAL_0 + PORT_SERIAL_LINE_STATUS) & 0x20;
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}
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void write_serial(char a) {
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while (is_transmit_empty() == 0);
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port_byte_out(PORT_SERIAL_0 + PORT_SERIAL_DATA, a);
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}
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void serial_kprint(char *msg) {
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u32 i = 0;
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while (1) {
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char c = msg[i];
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if (c == 0) {
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break;
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}
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if (c == '\n') {
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write_serial('\r');
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}
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write_serial(c);
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i++;
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}
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} |