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

   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
  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
  29extern raw_spinlock_t i8259A_lock;
  30
  31/* the PIC may need a careful delay on some platforms, hence specific calls */
  32static 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
  45static 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
  55extern struct irq_chip i8259A_chip;
  56
  57struct 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
  70extern struct legacy_pic *legacy_pic;
  71extern struct legacy_pic null_legacy_pic;
  72
  73static inline bool has_legacy_pic(void)
  74{
  75        return legacy_pic != &null_legacy_pic;
  76}
  77
  78static inline int nr_legacy_irqs(void)
  79{
  80        return legacy_pic->nr_legacy_irqs;
  81}
  82
  83#endif /* _ASM_X86_I8259_H */
  84