xref: /openbmc/linux/arch/x86/include/asm/i8259.h (revision 128b0c97)
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 #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 
31 extern raw_spinlock_t i8259A_lock;
32 
33 /* the PIC may need a careful delay on some platforms, hence specific calls */
inb_pic(unsigned int port)34 static 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 
outb_pic(unsigned char value,unsigned int port)47 static 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 
57 extern struct irq_chip i8259A_chip;
58 
59 struct 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 
72 void legacy_pic_pcat_compat(void);
73 
74 extern struct legacy_pic *legacy_pic;
75 extern struct legacy_pic null_legacy_pic;
76 
has_legacy_pic(void)77 static inline bool has_legacy_pic(void)
78 {
79 	return legacy_pic != &null_legacy_pic;
80 }
81 
nr_legacy_irqs(void)82 static inline int nr_legacy_irqs(void)
83 {
84 	return legacy_pic->nr_legacy_irqs;
85 }
86 
87 #endif /* _ASM_X86_I8259_H */
88