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
   7 extern unsigned int cached_irq_mask;
   8
   9 #define __byte(x, y)            (((unsigned char *)&(y))[x])
  10 #define cached_master_mask      (__byte(0, cached_irq_mask))
  11 #define cached_slave_mask       (__byte(1, cached_irq_mask))
  12
  13 /* i8259A PIC registers */
  14 #define PIC_MASTER_CMD          0x20
  15 #define PIC_MASTER_IMR          0x21
  16 #define PIC_MASTER_ISR          PIC_MASTER_CMD
  17 #define PIC_MASTER_POLL         PIC_MASTER_ISR
  18 #define PIC_MASTER_OCW3         PIC_MASTER_ISR
  19 #define PIC_SLAVE_CMD           0xa0
  20 #define PIC_SLAVE_IMR           0xa1
  21
  22 /* i8259A PIC related value */
  23 #define PIC_CASCADE_IR          2
  24 #define MASTER_ICW4_DEFAULT     0x01
  25 #define SLAVE_ICW4_DEFAULT      0x01
  26 #define PIC_ICW4_AEOI           2
  27
  28 extern raw_spinlock_t i8259A_lock;
  29
  30 /* the PIC may need a careful delay on some platforms, hence specific calls */
  31 static inline unsigned char inb_pic(unsigned int port)
  32 {
  33         unsigned char value = inb(port);
  34
  35         /*
  36          * delay for some accesses to PIC on motherboard or in chipset
  37          * must be at least one microsecond, so be safe here:
  38          */
  39         udelay(2);
  40
  41         return value;
  42 }
  43
  44 static inline void outb_pic(unsigned char value, unsigned int port)
  45 {
  46         outb(value, port);
  47         /*
  48          * delay for some accesses to PIC on motherboard or in chipset
  49          * must be at least one microsecond, so be safe here:
  50          */
  51         udelay(2);
  52 }
  53
  54 extern struct irq_chip i8259A_chip;
  55
  56 struct legacy_pic {
  57         int nr_legacy_irqs;
  58         struct irq_chip *chip;
  59         void (*mask)(unsigned int irq);
  60         void (*unmask)(unsigned int irq);
  61         void (*mask_all)(void);
  62         void (*restore_mask)(void);
  63         void (*init)(int auto_eoi);
  64         int (*probe)(void);
  65         int (*irq_pending)(unsigned int irq);
  66         void (*make_irq)(unsigned int irq);
  67 };
  68
  69 extern struct legacy_pic *legacy_pic;
  70 extern struct legacy_pic null_legacy_pic;
  71
  72 static inline bool has_legacy_pic(void)
  73 {
  74         return legacy_pic != &null_legacy_pic;
  75 }
  76
  77 static inline int nr_legacy_irqs(void)
  78 {
  79         return legacy_pic->nr_legacy_irqs;
  80 }
  81
  82 #endif /* _ASM_X86_I8259_H */