1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_I8259_H
3 #define _ASM_X86_I8259_H
4 
5 #include <linux/delay.h>
6 #include <asm/io.h>
7 
8 extern unsigned int cached_irq_mask;
9 
10 #define __byte(x, y)		(((unsigned char *)&(y))[x])
11 #define cached_master_mask	(__byte(0, cached_irq_mask))
12 #define cached_slave_mask	(__byte(1, cached_irq_mask))
13 
14 /* i8259A PIC registers */
15 #define PIC_MASTER_CMD		0x20
16 #define PIC_MASTER_IMR		0x21
17 #define PIC_MASTER_ISR		PIC_MASTER_CMD
18 #define PIC_MASTER_POLL		PIC_MASTER_ISR
19 #define PIC_MASTER_OCW3		PIC_MASTER_ISR
20 #define PIC_SLAVE_CMD		0xa0
21 #define PIC_SLAVE_IMR		0xa1
22 
23 /* i8259A PIC related value */
24 #define PIC_CASCADE_IR		2
25 #define MASTER_ICW4_DEFAULT	0x01
26 #define SLAVE_ICW4_DEFAULT	0x01
27 #define PIC_ICW4_AEOI		2
28 
29 extern raw_spinlock_t i8259A_lock;
30 
31 /* the PIC may need a careful delay on some platforms, hence specific calls */
inb_pic(unsigned int port)32 static inline unsigned char inb_pic(unsigned int port)
33 {
34 	unsigned char value = inb(port);
35 
36 	/*
37 	 * delay for some accesses to PIC on motherboard or in chipset
38 	 * must be at least one microsecond, so be safe here:
39 	 */
40 	udelay(2);
41 
42 	return value;
43 }
44 
outb_pic(unsigned char value,unsigned int port)45 static inline void outb_pic(unsigned char value, unsigned int port)
46 {
47 	outb(value, port);
48 	/*
49 	 * delay for some accesses to PIC on motherboard or in chipset
50 	 * must be at least one microsecond, so be safe here:
51 	 */
52 	udelay(2);
53 }
54 
55 extern struct irq_chip i8259A_chip;
56 
57 struct legacy_pic {
58 	int nr_legacy_irqs;
59 	struct irq_chip *chip;
60 	void (*mask)(unsigned int irq);
61 	void (*unmask)(unsigned int irq);
62 	void (*mask_all)(void);
63 	void (*restore_mask)(void);
64 	void (*init)(int auto_eoi);
65 	int (*probe)(void);
66 	int (*irq_pending)(unsigned int irq);
67 	void (*make_irq)(unsigned int irq);
68 };
69 
70 extern struct legacy_pic *legacy_pic;
71 extern struct legacy_pic null_legacy_pic;
72 
has_legacy_pic(void)73 static inline bool has_legacy_pic(void)
74 {
75 	return legacy_pic != &null_legacy_pic;
76 }
77 
nr_legacy_irqs(void)78 static inline int nr_legacy_irqs(void)
79 {
80 	return legacy_pic->nr_legacy_irqs;
81 }
82 
83 #endif /* _ASM_X86_I8259_H */
84