LXR linux/arch/x86/include/asm/i8259.h

   1#ifndef _ASM_X86_I8259_H
   2#define _ASM_X86_I8259_H
   3
   4#include <linux/delay.h>
   5
   6extern 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
  27extern raw_spinlock_t i8259A_lock;
  28
  29/* the PIC may need a careful delay on some platforms, hence specific calls */
  30static 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
  43static 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
  53extern struct irq_chip i8259A_chip;
  54
  55struct 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 (*irq_pending)(unsigned int irq);
  64        void (*make_irq)(unsigned int irq);
  65};
  66
  67extern struct legacy_pic *legacy_pic;
  68extern struct legacy_pic null_legacy_pic;
  69
  70static inline int nr_legacy_irqs(void)
  71{
  72        return legacy_pic->nr_legacy_irqs;
  73}
  74
  75#endif /* _ASM_X86_I8259_H */
  76