1 /* 2 * Basic support for controlling the 8259 Programmable Interrupt Controllers. 3 * 4 * Initially written by Michael Brown (mcb30). 5 */ 6 7 FILE_LICENCE ( GPL2_OR_LATER ); 8 9 #ifndef PIC8259_H 10 #define PIC8259_H 11 12 /* For segoff_t */ 13 #include "realmode.h" 14 15 #define IRQ_PIC_CUTOFF 8 16 17 /* 8259 register locations */ 18 #define PIC1_ICW1 0x20 19 #define PIC1_OCW2 0x20 20 #define PIC1_OCW3 0x20 21 #define PIC1_ICR 0x20 22 #define PIC1_IRR 0x20 23 #define PIC1_ISR 0x20 24 #define PIC1_ICW2 0x21 25 #define PIC1_ICW3 0x21 26 #define PIC1_ICW4 0x21 27 #define PIC1_IMR 0x21 28 #define PIC2_ICW1 0xa0 29 #define PIC2_OCW2 0xa0 30 #define PIC2_OCW3 0xa0 31 #define PIC2_ICR 0xa0 32 #define PIC2_IRR 0xa0 33 #define PIC2_ISR 0xa0 34 #define PIC2_ICW2 0xa1 35 #define PIC2_ICW3 0xa1 36 #define PIC2_ICW4 0xa1 37 #define PIC2_IMR 0xa1 38 39 /* Register command values */ 40 #define OCW3_ID 0x08 41 #define OCW3_READ_IRR 0x03 42 #define OCW3_READ_ISR 0x02 43 #define ICR_EOI_NON_SPECIFIC 0x20 44 #define ICR_EOI_NOP 0x40 45 #define ICR_EOI_SPECIFIC 0x60 46 #define ICR_EOI_SET_PRIORITY 0xc0 47 48 /* Macros to enable/disable IRQs */ 49 #define IMR_REG(x) ( (x) < IRQ_PIC_CUTOFF ? PIC1_IMR : PIC2_IMR ) 50 #define IMR_BIT(x) ( 1 << ( (x) % IRQ_PIC_CUTOFF ) ) 51 #define irq_enabled(x) ( ( inb ( IMR_REG(x) ) & IMR_BIT(x) ) == 0 ) 52 #define enable_irq(x) outb ( inb( IMR_REG(x) ) & ~IMR_BIT(x), IMR_REG(x) ) 53 #define disable_irq(x) outb ( inb( IMR_REG(x) ) | IMR_BIT(x), IMR_REG(x) ) 54 55 /* Macros for acknowledging IRQs */ 56 #define ICR_REG( irq ) ( (irq) < IRQ_PIC_CUTOFF ? PIC1_ICR : PIC2_ICR ) 57 #define ICR_VALUE( irq ) ( (irq) % IRQ_PIC_CUTOFF ) 58 #define CHAINED_IRQ 2 59 60 /* Utility macros to convert IRQ numbers to INT numbers and INT vectors */ 61 #define IRQ_INT( irq ) ( ( ( (irq) - IRQ_PIC_CUTOFF ) ^ 0x70 ) & 0x7f ) 62 63 /* Other constants */ 64 #define IRQ_MAX 15 65 #define IRQ_NONE -1U 66 67 /* Function prototypes 68 */ 69 void send_eoi ( unsigned int irq ); 70 71 #endif /* PIC8259_H */ 72
