1 #ifndef __ASM_I8259_H__
2 #define __ASM_I8259_H__
4 #include <linux/delay.h>
6 extern unsigned int cached_irq_mask;
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))
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
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
27 extern spinlock_t i8259A_lock;
29 extern void init_8259A(int auto_eoi);
30 extern void enable_8259A_irq(unsigned int irq);
31 extern void disable_8259A_irq(unsigned int irq);
32 extern unsigned int startup_8259A_irq(unsigned int irq);
34 /* the PIC may need a careful delay on some platforms, hence specific calls */
35 static inline unsigned char inb_pic(unsigned int port)
37 unsigned char value = inb(port);
40 * delay for some accesses to PIC on motherboard or in chipset
41 * must be at least one microsecond, so be safe here:
48 static inline void outb_pic(unsigned char value, unsigned int port)
52 * delay for some accesses to PIC on motherboard or in chipset
53 * must be at least one microsecond, so be safe here:
58 extern struct irq_chip i8259A_chip;
60 #endif /* __ASM_I8259_H__ */