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#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
  31extern raw_spinlock_t i8259A_lock;
  32
  33/* the PIC may need a careful delay on some platforms, hence specific calls */
  34static 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
  47static 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
  57extern struct irq_chip i8259A_chip;
  58
  59struct 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
  72extern struct legacy_pic *legacy_pic;
  73extern struct legacy_pic null_legacy_pic;
  74
  75static inline bool has_legacy_pic(void)
  76{
  77        return legacy_pic != &null_legacy_pic;
  78}
  79
  80static inline int nr_legacy_irqs(void)
  81{
  82        return legacy_pic->nr_legacy_irqs;
  83}
  84
  85#endif /* _ASM_X86_I8259_H */
  86