kernel/arch/x86/time/i8254.c

   1 #include <time/i8254.h>
   2
   3 uint16_t reload;
   4
   5 void i8254_configure_channel(char channel, char opmode, uint16_t new_reload)
   6 {
   7         union mode_command command;
   8
   9         command.fields.bcd = 0;
  10         command.fields.channel = channel;
  11         command.fields.acmode = ACMODE_LSB_MSB;
  12         command.fields.opmode = opmode;
  13
  14         outb(PORT_MODE_CMD_REG, command.command);
  15
  16         switch (channel) {
  17                 case 0:
  18                         outb(PORT_CHANNEL_0_DATA, new_reload & 0xff);
  19                         outb(PORT_CHANNEL_0_DATA, new_reload >> 8);
  20                         break;
  21                 case 1:
  22                         outb(PORT_CHANNEL_1_DATA, new_reload & 0xff);
  23                         outb(PORT_CHANNEL_1_DATA, new_reload >> 8);
  24                         break;
  25                 case 2:
  26                         outb(PORT_CHANNEL_2_DATA, new_reload & 0xff);
  27                         outb(PORT_CHANNEL_2_DATA, new_reload >> 8);
  28                         break;
  29         }
  30
  31         reload = new_reload;
  32 }
  33
  34 void i8254_irq_enable()
  35 {
  36         pic_unmask(0);
  37 }