LCD Control driver in Debian 2.26 written in C

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  Sample C file text
  
  
  #define BASE 0x378
  #define I_REGISTER 2
  #define D_REGISTER 0
  #define WRITE_DATA 8
  
  #define Superio_index 0x2e
  #define Superio_data 0x2f
  #define BANK_REG 0x07
  
  #define timeout_value 5 //Set time out value, the default value is 5 seconds
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <time.h>
  #include <signal.h>
  #include <unistd.h>
  #include <sys/io.h>
  #include <sys/types.h>
  #include <sys/utsname.h>
  #include <sys/perm.h>
  #include <sys/time.h>
  
  int status;
  pid_t pid;
  
  
  // LCD display control functions
  void display_on(void);
  void display_off(void);
  void clear_display(void);
  void return_home(void);
  void entry_mode(void);
  void function_set(void);
  void initialize_display(void);
  void print_character(int character);
  int detect_all_press();
  
  void open_LCD(void);
  void close_LCD(void);
  void timeout(void);
  int btn_pressed=0, count_end=1;
  
  // Functions for making screens to send to the LCD
  void main_loop(void);
  
  // Main function
  int main(void)
  {
  int width; // LCD screen width
  int height; // LCD screen height
  int i; // Just a counter
  width = 16;
  height = 2;
  ioperm(BASE, 3, 1); // Get permission to the prallel port
  outb(0, BASE + 2); // Make sure there is power on C0
  initialize_display(); // Initialize the display
  main_loop();
  display_off();
  ioperm(BASE, 3, 0);
  return 0;
  }
  
  void open_LCD(void)
  {
  int data_temp;
  ioperm(Superio_index, 2, 1); //Get permission to the GPIO port
  outb(0x87, Superio_index);
  outb(0x87, Superio_index);
  outb(BANK_REG, Superio_index);
  outb(BANK_REG, Superio_data);
  outb(0xf1, Superio_index);
  data_temp=inb(Superio_data);
  data_temp&=~(0x10);
  outb(data_temp, Superio_data);
  ioperm(Superio_index, 2, 0); //Cloase permission to the GPIO port
  }
  
  void close_LCD(void)
  {
  int data_temp;
  ioperm(Superio_index, 2, 1); //Get permission to the GPIO port
  outb(0x87, Superio_index);
  outb(0x87, Superio_index);
  outb(BANK_REG, Superio_index);
  outb(BANK_REG, Superio_data);
  outb(0xf1, Superio_index);
  data_temp=inb(Superio_data);
  data_temp|=0x10;
  outb(data_temp, Superio_data);
  ioperm(Superio_index, 2, 0); //Cloase permission to the GPIO port
  }
  
  void timeout(void)
  {
  btn_pressed=1;
  count_end=0;
  }
  
  void display_on(void)
  {
  outb(12, BASE); //Turn on D3 and D4
  outb(I_REGISTER + WRITE_DATA, BASE + 2); //Turn off C1 and C3
  outb(4 + I_REGISTER + WRITE_DATA, BASE + 2); //Turn on C2 while C1 and C3 remains off
  outb(I_REGISTER + WRITE_DATA, BASE + 2); //Reset Control pins
  usleep(0);
  }
  
  
  
  void display_off(void)
  {
  outb(8, BASE); //Turn on D3 and D4
  outb(I_REGISTER + WRITE_DATA, BASE + 2); //Turn off C1 and C3
  outb(4 + I_REGISTER + WRITE_DATA, BASE + 2); //Turn on C2 while C1 and C3 remains off
  outb(I_REGISTER + WRITE_DATA, BASE + 2); //Reset Control pins
  usleep(0);
  }
  
  
  void clear_display(void)
  {
  outb(1, BASE); //Turn on D0
  outb(I_REGISTER + WRITE_DATA, BASE + 2); //Turn off C1 and C3
  outb(4 + I_REGISTER + WRITE_DATA, BASE + 2); //Turn on C2 while C1 and C3 remains off
  outb(I_REGISTER + WRITE_DATA, BASE + 2); //Reset Control pins
  usleep(0);
  }
  
  
  void return_home(void)
  {
  outb(2, BASE); //Turn on D1
  outb(I_REGISTER + WRITE_DATA, BASE + 2); //Turn off C1 and C3
  outb(4 + I_REGISTER + WRITE_DATA, BASE + 2); //Turn on C2 while C1 and C3 remains off
  // usleep(1); //Wait while Enable (C2) is high so LCD will have time to load the info
  outb(I_REGISTER + WRITE_DATA, BASE + 2); //Reset Control pins
  usleep(0);
  }
  
  
  void entry_mode(void)
  {
  outb(6, BASE); //Turn on D1 and D2
  outb(I_REGISTER + WRITE_DATA, BASE + 2); //Turn off C1 and C3
  outb(4 + I_REGISTER + WRITE_DATA, BASE + 2); //Turn on C2 while C1 and C3 remains off
  outb(I_REGISTER + WRITE_DATA, BASE + 2); //Reset Control pins
  usleep(0);
  }
  
  
  void function_set(void)
  {
  outb(56, BASE); //Turn on D3, D4 and D5
  outb(I_REGISTER + WRITE_DATA, BASE + 2); //Turn off C1 and C3
  outb(4 + I_REGISTER + WRITE_DATA, BASE + 2); //Turn on C2 while C1 and C3 remains off
  outb(I_REGISTER + WRITE_DATA, BASE + 2); //Reset Control pins
  usleep(0);
  }
  
  
  void initialize_display(void)
  {
  function_set();
  function_set();
  entry_mode();
  display_on();
  clear_display();
  }
  
  
  void print_character(int character)
  {
  outb(D_REGISTER + WRITE_DATA, BASE + 2); //Set register to Write Data
  outb(character, BASE); // Set the character code
  outb(4 + D_REGISTER + WRITE_DATA, BASE + 2); //Enable High
  outb(D_REGISTER + WRITE_DATA, BASE + 2); //Disable High
  usleep(0); //Wait while Enable (C2) is high so LCD will have time to load the info
  }
  
  
  int detect_all_press()
  {
  unsigned char b123;
  b123 = 0xF0 & inb(0x379);
  switch(b123){
  case 0x70: //don't press any button
  return 0;
  break;
  case 0x30: //button left
  return 1;
  break;
  case 0x60: //button up
  return 2;
  break;
  case 0xF0: //button right
  return 3;
  break;
  case 0x50: //button down
  return 4;
  break;
  case 0xB0: //button left & right to exit
  return 5;
  break;
  default:
  return 0;
  break;
  }
  }
  
  void main_loop(void)
  {
  int x, retval, timer_counter=0;
  char clearbr[]=" up"; //show word
  char bypassoff[]=" right";
  char aewinos[]=" down";
  char bypasson[]=" left";
  unsigned char d123=0, c123;
  pid=fork();
  // printf("PID= %d\n", pid);
  if(pid==0)
  {
  // printf("Signal Alarm timeout!\n");
  signal(SIGALRM,timeout); //excute timeout func as soon as receive the SIGALRM
  // printf("Process Signal timeout\n");
  while(1)
  {
  if(btn_pressed)
  {
  btn_pressed=0;
  timer_counter=timeout_value;
  }
  else if(!count_end)
  {
  timer_counter--;
  sleep(1);
  if(!timer_counter) //If timer count out, Excute close_LCD,
  {
  close_LCD();
  timer_counter=timeout_value;
  count_end=1;
  }
  }
  // printf("it is in child process\n");
  }
  exit(0);
  }
  else if(pid==-1)
  {
  printf("The Timer subprocess was not created! \n");
  }
  else
  {
  // printf("PID= %d\n",pid);
  while(1){
  c123=detect_all_press(); //?sbuttonA
  if ((d123 != 1) && (c123 == 1)){
  clear_display();
  for(x = 0; x < strlen(clearbr); x++)
  print_character(clearbr[x]); //display "left" in lcm
  open_LCD();
  kill(pid,SIGALRM);
  printf("up\n"); //print in computer
  }
  if ((d123 != 2) && (c123 == 2)){
  clear_display();
  for(x = 0; x < strlen(bypassoff); x++)
  print_character(bypassoff[x]); //display "up"
  open_LCD();
  kill(pid,SIGALRM);
  printf("right\n");
  }
  if ((d123 != 3) && (c123 == 3)){
  clear_display();
  for(x = 0; x < strlen(aewinos); x++)
  print_character(aewinos[x]); //display "right"
  open_LCD();
  kill(pid,SIGALRM);
  printf("down\n");
  }
  if ((d123 != 4) && (c123 == 4)){
  clear_display();
  for(x = 0; x < strlen(bypasson); x++)
  print_character(bypasson[x]); //display "down"
  open_LCD();
  kill(pid,SIGALRM);
  printf("left\n");
  }
  if ((d123 != 5) && (c123 == 5)){
  clear_display();
  close_LCD();
  retval = kill( pid,SIGKILL );
  if ( retval )
  {
  puts( "kill failed." );
  perror( "kill" );
  waitpid( pid, &status, 0 );
  }
  else
  {
  printf("LCD test is exited!\n");
  }
  break; //?kP?loopAM?`{
  }
  return_home();
  d123=c123; //OUbuttonA d?Uj
  }
  }
  }

  over 1 year ago

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