/*
 * https://wiki.osdev.org/%228042%22_PS/2_Controller
 */

#include "keyboard.h"
#include "ps2_controller.h"
#include <stdint.h>
#include <stdio.h>
#include <sys/io.h>

// r   status register
//  w  command register
#define comm_port 0x64
#define comm_enable_first_ps2 0xae
#define comm_read_ctrl_config 0x20
#define comm_write_ctrl_config 0x60

#define data_port 0x60
#define data_enable_scanning 0xf4

void
ps2_ctrl_init()
{
  // eat all previous keystrikes
  while (inb(comm_port) & 0x1) inb(data_port);

  uint8_t test;
  outb(0xaa, comm_port);
  test = inb(data_port);
  printf("i8042: self test  0xaa:%x %s\n", test, test == 0x55 ? "ok" : "failed");
  outb(0xab, comm_port);
  test = inb(data_port);
  printf("i8042: port1 test 0xab:%x %s\n", test, test == 0x00 ? "ok" : "failed");
  outb(0xa9, comm_port);
  test = inb(data_port);
  printf("i8042: port2 test 0xa9:%x %s\n", test, test == 0x00 ? "ok" : "failed");

  // printf("8042: init keyboard\n");

  outb(comm_enable_first_ps2, comm_port);
  outb(comm_read_ctrl_config, comm_port);
  const uint8_t conf = (inb(data_port) | 1) & ~0x10;
  outb(comm_write_ctrl_config, comm_port);

  outb(conf, data_port);
  outb(data_enable_scanning, data_port);
}

unsigned char
kbd_read_next()
{
  return inb(data_port);
}