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i8259.h
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1 #ifndef _ASM_X86_I8259_H
2 #define _ASM_X86_I8259_H
3 
4 #include <linux/delay.h>
5 
6 extern unsigned int cached_irq_mask;
7 
8 #define __byte(x, y) (((unsigned char *)&(y))[x])
9 #define cached_master_mask (__byte(0, cached_irq_mask))
10 #define cached_slave_mask (__byte(1, cached_irq_mask))
11 
12 /* i8259A PIC registers */
13 #define PIC_MASTER_CMD 0x20
14 #define PIC_MASTER_IMR 0x21
15 #define PIC_MASTER_ISR PIC_MASTER_CMD
16 #define PIC_MASTER_POLL PIC_MASTER_ISR
17 #define PIC_MASTER_OCW3 PIC_MASTER_ISR
18 #define PIC_SLAVE_CMD 0xa0
19 #define PIC_SLAVE_IMR 0xa1
20 
21 /* i8259A PIC related value */
22 #define PIC_CASCADE_IR 2
23 #define MASTER_ICW4_DEFAULT 0x01
24 #define SLAVE_ICW4_DEFAULT 0x01
25 #define PIC_ICW4_AEOI 2
26 
28 
29 /* the PIC may need a careful delay on some platforms, hence specific calls */
30 static inline unsigned char inb_pic(unsigned int port)
31 {
32  unsigned char value = inb(port);
33 
34  /*
35  * delay for some accesses to PIC on motherboard or in chipset
36  * must be at least one microsecond, so be safe here:
37  */
38  udelay(2);
39 
40  return value;
41 }
42 
43 static inline void outb_pic(unsigned char value, unsigned int port)
44 {
45  outb(value, port);
46  /*
47  * delay for some accesses to PIC on motherboard or in chipset
48  * must be at least one microsecond, so be safe here:
49  */
50  udelay(2);
51 }
52 
53 extern struct irq_chip i8259A_chip;
54 
55 struct legacy_pic {
57  struct irq_chip *chip;
58  void (*mask)(unsigned int irq);
59  void (*unmask)(unsigned int irq);
62  void (*init)(int auto_eoi);
63  int (*irq_pending)(unsigned int irq);
64  void (*make_irq)(unsigned int irq);
65 };
66 
67 extern struct legacy_pic *legacy_pic;
68 extern struct legacy_pic null_legacy_pic;
69 
70 #endif /* _ASM_X86_I8259_H */