xref: /openbmc/linux/arch/x86/include/asm/i8259.h (revision 2d96b44f)
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 
27 extern raw_spinlock_t i8259A_lock;
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 {
56 	int nr_legacy_irqs;
57 	struct irq_chip *chip;
58 	void (*mask)(unsigned int irq);
59 	void (*unmask)(unsigned int irq);
60 	void (*mask_all)(void);
61 	void (*restore_mask)(void);
62 	void (*init)(int auto_eoi);
63 	int (*probe)(void);
64 	int (*irq_pending)(unsigned int irq);
65 	void (*make_irq)(unsigned int irq);
66 };
67 
68 extern struct legacy_pic *legacy_pic;
69 extern struct legacy_pic null_legacy_pic;
70 
71 static inline int nr_legacy_irqs(void)
72 {
73 	return legacy_pic->nr_legacy_irqs;
74 }
75 
76 #endif /* _ASM_X86_I8259_H */
77