kernel/drivers/irq/i8259a.c

   1 #include <io.h>
   2 #include <tty.h>
   3 #include <irq/i8259a.h>
   4
   5 void pic_init(int offset1, int offset2)
   6 {
   7         uint8_t a1, a2;
   8
   9         a1 = inb(PIC1_DATA);
  10         a2 = inb(PIC2_DATA);
  11
  12         outb(PIC1_COMMAND, PIC_ICW1_INIT | PIC_ICW1_ICW4);
  13         io_wait();
  14         outb(PIC2_COMMAND, PIC_ICW1_INIT | PIC_ICW1_ICW4);
  15         io_wait();
  16         outb(PIC1_DATA, offset1);
  17         io_wait();
  18         outb(PIC2_DATA, offset2);
  19         io_wait();
  20         outb(PIC1_DATA, 4);
  21         io_wait();
  22         outb(PIC2_DATA, 2);
  23         io_wait();
  24
  25         outb(PIC1_DATA, PIC_ICW4_8086);
  26         io_wait();
  27         outb(PIC2_DATA, PIC_ICW4_8086);
  28         io_wait();
  29
  30         outb(PIC1_DATA, a1);
  31         outb(PIC2_DATA, a2);
  32 }
  33
  34 void pic_mask(uint8_t irq)
  35 {
  36         uint16_t port;
  37         uint8_t value;
  38
  39         if (irq < 8) {
  40                 port = PIC1_DATA;
  41         } else {
  42                 port = PIC2_DATA;
  43         }
  44
  45         value = inb(port) | (1 << irq);
  46         outb(port, value);
  47 }
  48
  49 void pic_unmask(uint8_t irq)
  50 {
  51         uint16_t port;
  52         uint8_t value;
  53
  54         if (irq < 8) {
  55                 port = PIC1_DATA;
  56         } else {
  57                 port = PIC2_DATA;
  58         }
  59
  60         value = inb(port) & ~(1 << irq);
  61         outb(port, value);
  62 }
  63
  64 void pic_mask_all(void)
  65 {
  66         outb(PIC1_DATA, 0xFF);
  67 }
  68
  69 void pic_unmask_all(void)
  70 {
  71         outb(PIC1_DATA, 0);
  72 }
  73
  74 void pic_send_eoi(uint8_t irq)
  75 {
  76         if (irq >= 8)
  77                 outb(PIC2_COMMAND, PIC_EOI);
  78
  79         outb(PIC1_COMMAND, PIC_EOI);
  80 }