arch/i386-pc/drivers/keyboard/kbd_common.c

   1 /*
   2     Copyright © 1995-2013, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: PS/2 keyboard driver.
   6     Lang: English.
   7 */
   8
   9 #include "kbd.h"
  10 #define TIMER_RPROK 3599597124UL
  11
  12 int kbd_wait_for_input(void);
  13
  14 static ULONG usec2tick(ULONG usec)
  15 {
  16     ULONG ret;
  17     ULONG prok = TIMER_RPROK;
  18     asm volatile("movl $0,%%eax; divl %2":"=a"(ret):"d"(usec),"m"(prok));
  19     return ret;
  20 }
  21
  22 static void kbd_usleep(LONG usec)
  23 {
  24     int oldtick, tick;
  25     usec = usec2tick(usec);
  26
  27     outb(0x80, 0x43);
  28     oldtick = inb(0x42);
  29     oldtick += inb(0x42) << 8;
  30
  31     while (usec > 0)
  32     {
  33         outb(0x80, 0x43);
  34         tick = inb(0x42);
  35         tick += inb(0x42) << 8;
  36
  37         usec -= (oldtick - tick);
  38         if (tick > oldtick) usec -= 0x10000;
  39         oldtick = tick;
  40     }
  41 }
  42
  43 unsigned char handle_kbd_event(void)
  44 {
  45     unsigned char status = kbd_read_status();
  46     unsigned int work = 10000;
  47
  48     while (status & KBD_STATUS_OBF)
  49     {
  50         kbd_read_input();
  51
  52         status = kbd_read_status();
  53         if(!work--)
  54         {
  55             //printf(KERN_ERR "pc_keyb: controller jammed (0x%02X).\n",status);
  56             break;
  57         }
  58     }
  59     return status;
  60 }
  61
  62 /*
  63  * Wait until we can write to a peripheral again. Any input that comes in
  64  * while we're waiting is discarded.
  65  */
  66 void kb_wait(void)
  67 {
  68     ULONG timeout = 100; /* 0.1 sec should be enough */
  69
  70     do
  71     {
  72         unsigned char status = handle_kbd_event();
  73         if (! (status & KBD_STATUS_IBF))
  74             return;
  75
  76         kbd_usleep(1000);
  77         timeout--;
  78     } while (timeout);
  79 }
  80
  81 void kbd_write_cmd(int cmd)
  82 {
  83     kb_wait();
  84     kbd_write_command(KBD_CTRLCMD_WRITE_MODE);
  85     kb_wait();
  86     kbd_write_output(cmd);
  87 }
  88
  89 void kbd_write_output_w(int data)
  90 {
  91     kb_wait();
  92     kbd_write_output(data);
  93 }
  94
  95 void kbd_write_command_w(int data)
  96 {
  97     kb_wait();
  98     kbd_write_command(data);
  99 }
 100
 101 #define KBD_NO_DATA     (-1)
 102 #define KBD_BAD_DATA    (-2)
 103
 104 int kbd_read_data(void)
 105 {
 106     LONG        retval = KBD_NO_DATA;
 107     UBYTE       status;
 108
 109     status = kbd_read_status();
 110     if (status & KBD_STATUS_OBF)
 111     {
 112         UBYTE   data = kbd_read_input();
 113
 114         retval = data;
 115         if (status & (KBD_STATUS_GTO | KBD_STATUS_PERR))
 116             retval = KBD_BAD_DATA;
 117     }
 118
 119     return retval;
 120 }
 121
 122 int kbd_clear_input(void)
 123 {
 124     int maxread = 100, code, lastcode = KBD_NO_DATA;
 125     UBYTE status;
 126
 127     do
 128     {
 129         status = kbd_read_status();
 130         if ((code = kbd_read_data()) == KBD_NO_DATA)
 131             break;
 132         if (!(status & KBD_STATUS_MOUSE_OBF))
 133             lastcode = code;
 134     } while (--maxread);
 135
 136     return lastcode;
 137 }
 138
 139 int kbd_wait_for_input(void)
 140 {
 141     ULONG timeout = 100;
 142
 143     do
 144     {
 145         int retval = kbd_read_data();
 146         if (retval >= 0)
 147             return retval;
 148         kbd_usleep(1000);
 149     } while(--timeout);
 150     return -1;
 151 }
 152