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
8extern 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#define PIC_ELCR1		0x4d0
23#define PIC_ELCR2		0x4d1
24
25/* i8259A PIC related value */
26#define PIC_CASCADE_IR		2
27#define MASTER_ICW4_DEFAULT	0x01
28#define SLAVE_ICW4_DEFAULT	0x01
29#define PIC_ICW4_AEOI		2
30
31extern raw_spinlock_t i8259A_lock;
32
33/* the PIC may need a careful delay on some platforms, hence specific calls */
34static inline unsigned char inb_pic(unsigned int port)
35{
36	unsigned char value = inb(port);
37
38	/*
39	 * delay for some accesses to PIC on motherboard or in chipset
40	 * must be at least one microsecond, so be safe here:
41	 */
42	udelay(2);
43
44	return value;
45}
46
47static inline void outb_pic(unsigned char value, unsigned int port)
48{
49	outb(value, port);
50	/*
51	 * delay for some accesses to PIC on motherboard or in chipset
52	 * must be at least one microsecond, so be safe here:
53	 */
54	udelay(2);
55}
56
57extern struct irq_chip i8259A_chip;
58
59struct legacy_pic {
60	int nr_legacy_irqs;
61	struct irq_chip *chip;
62	void (*mask)(unsigned int irq);
63	void (*unmask)(unsigned int irq);
64	void (*mask_all)(void);
65	void (*restore_mask)(void);
66	void (*init)(int auto_eoi);
67	int (*probe)(void);
68	int (*irq_pending)(unsigned int irq);
69	void (*make_irq)(unsigned int irq);
70};
71
72void legacy_pic_pcat_compat(void);
73
74extern struct legacy_pic *legacy_pic;
75extern struct legacy_pic null_legacy_pic;
76
77static inline bool has_legacy_pic(void)
78{
79	return legacy_pic != &null_legacy_pic;
80}
81
82static inline int nr_legacy_irqs(void)
83{
84	return legacy_pic->nr_legacy_irqs;
85}
86
87#endif /* _ASM_X86_I8259_H */
88