drivers/char/lcd_16207.c

   1 #include <linux/module.h>
   2 #include <linux/errno.h>
   3 #include <linux/cdev.h>
   4 #include <linux/types.h>
   5 #include <linux/errno.h>
   6 #include <linux/miscdevice.h>
   7 #include <linux/slab.h>
   8 #include <linux/ioport.h>
   9 #include <linux/fcntl.h>
  10 #include <linux/mc146818rtc.h>
  11 #include <linux/netdevice.h>
  12 #include <linux/sched.h>
  13 #include <linux/delay.h>
  14
  15 #include <asm/io.h>
  16 #include <asm/uaccess.h>
  17 #include <asm/system.h>
  18 #include <linux/delay.h>
  19
  20 #define LCD_On 1
  21 #define LCD_Off 2
  22 #define LCD_Clear 3
  23 #define LCD_Reset 4
  24 #define LCD_Cursor_Left 5
  25 #define LCD_Cursor_Right 6
  26 #define LCD_Disp_Left 7
  27 #define LCD_Disp_Right 8
  28 #define LCD_Get_Cursor 9
  29 #define LCD_Set_Cursor 10
  30 #define LCD_Home 11
  31 #define LCD_Read 12
  32 #define LCD_Write 13
  33 #define LCD_Cursor_Off 14
  34 #define LCD_Cursor_On 15
  35 #define LCD_Get_Cursor_Pos 16
  36 #define LCD_Set_Cursor_Pos 17
  37 #define LCD_Blink_Off 18
  38
  39 #define kLCD_IR na_lcd_16207_0
  40 #define kLCD_DR (na_lcd_16207_0 + 8)
  41
  42 #define LCDWriteData(x) outl(x , kLCD_DR)
  43 #define LCDWriteInst(x) outl(x , kLCD_IR)
  44
  45 #define LCDReadData inl(kLCD_DR)
  46 #define LCDReadInst inl(kLCD_IR)
  47
  48
  49 #define Major 250
  50
  51 static int Device_Open = 0;
  52
  53 static int lcd_16207_ioctl(struct inode *inode,struct file *filp,
  54                            unsigned int cmd,unsigned long arg);
  55
  56 static int lcd_16207_open(struct inode *inode,struct file *filp)
  57 {
  58   static int counter = 0;
  59   if(Device_Open)return -EBUSY;
  60   Device_Open++;
  61   printk("You have open the device %d times\n",counter++);
  62   return 0;
  63 }
  64
  65 static int lcd_16207_release(struct inode *inode,struct file *filp)
  66 {
  67   Device_Open--;
  68   printk("You have release the device\n");
  69   return 0;
  70 }
  71
  72 static int lcd_16207_ioctl(struct inode *inode,struct file *filp,
  73                            unsigned int cmd,unsigned long arg)
  74 {
  75   volatile unsigned long display;
  76
  77   switch (cmd) {
  78   case LCD_On:
  79     if (copy_from_user
  80         (&display, (unsigned long *) arg,
  81          sizeof(display)))
  82       return -EFAULT;
  83
  84     LCDWriteInst(display);
  85     break;
  86
  87   case LCD_Off:
  88     if (copy_from_user
  89         (&display, (unsigned long *) arg,
  90          sizeof(display)))
  91       return -EFAULT;
  92
  93     LCDWriteData(display);
  94     break;
  95
  96
  97   default:
  98     return -EINVAL;
  99   }
 100
 101   return 0;
 102 }
 103
 104 static struct file_operations lcd_16207_fops={
 105   .ioctl = lcd_16207_ioctl,
 106   .open = lcd_16207_open,
 107   .release = lcd_16207_release,
 108 };
 109
 110 static int lcd_16207_init(void)
 111 {
 112   int ret = register_chrdev(Major,"LCD_PIO",&lcd_16207_fops);
 113   if(ret<0)
 114     {
 115       printk("Registering the device failed with %d\n",Major);
 116       return Major;
 117     }
 118   printk("You have init Device %d\n",Major);
 119   return 0;
 120 }
 121
 122 static void lcd_16207_exit(void)
 123 {
 124   if(unregister_chrdev(Major,"LCD_PIO"))
 125     printk("exit failed");
 126 }
 127
 128 module_init(lcd_16207_init);
 129 module_exit(lcd_16207_exit);
 130
 131 MODULE_AUTHOR("Andrew Bose");
 132 MODULE_LICENSE("GPL");