| /* |
| * Basic support for controlling the 8259 Programmable Interrupt Controllers. |
| * |
| * Initially written by Michael Brown (mcb30). |
| */ |
| |
| FILE_LICENCE ( GPL2_OR_LATER ); |
| |
| #ifndef PIC8259_H |
| #define PIC8259_H |
| |
| /* For segoff_t */ |
| #include "realmode.h" |
| |
| #define IRQ_PIC_CUTOFF 8 |
| |
| /* 8259 register locations */ |
| #define PIC1_ICW1 0x20 |
| #define PIC1_OCW2 0x20 |
| #define PIC1_OCW3 0x20 |
| #define PIC1_ICR 0x20 |
| #define PIC1_IRR 0x20 |
| #define PIC1_ISR 0x20 |
| #define PIC1_ICW2 0x21 |
| #define PIC1_ICW3 0x21 |
| #define PIC1_ICW4 0x21 |
| #define PIC1_IMR 0x21 |
| #define PIC2_ICW1 0xa0 |
| #define PIC2_OCW2 0xa0 |
| #define PIC2_OCW3 0xa0 |
| #define PIC2_ICR 0xa0 |
| #define PIC2_IRR 0xa0 |
| #define PIC2_ISR 0xa0 |
| #define PIC2_ICW2 0xa1 |
| #define PIC2_ICW3 0xa1 |
| #define PIC2_ICW4 0xa1 |
| #define PIC2_IMR 0xa1 |
| |
| /* Register command values */ |
| #define OCW3_ID 0x08 |
| #define OCW3_READ_IRR 0x03 |
| #define OCW3_READ_ISR 0x02 |
| #define ICR_EOI_NON_SPECIFIC 0x20 |
| #define ICR_EOI_NOP 0x40 |
| #define ICR_EOI_SPECIFIC 0x60 |
| #define ICR_EOI_SET_PRIORITY 0xc0 |
| |
| /* Macros to enable/disable IRQs */ |
| #define IMR_REG(x) ( (x) < IRQ_PIC_CUTOFF ? PIC1_IMR : PIC2_IMR ) |
| #define IMR_BIT(x) ( 1 << ( (x) % IRQ_PIC_CUTOFF ) ) |
| #define irq_enabled(x) ( ( inb ( IMR_REG(x) ) & IMR_BIT(x) ) == 0 ) |
| #define enable_irq(x) outb ( inb( IMR_REG(x) ) & ~IMR_BIT(x), IMR_REG(x) ) |
| #define disable_irq(x) outb ( inb( IMR_REG(x) ) | IMR_BIT(x), IMR_REG(x) ) |
| |
| /* Macros for acknowledging IRQs */ |
| #define ICR_REG( irq ) ( (irq) < IRQ_PIC_CUTOFF ? PIC1_ICR : PIC2_ICR ) |
| #define ICR_VALUE( irq ) ( (irq) % IRQ_PIC_CUTOFF ) |
| #define CHAINED_IRQ 2 |
| |
| /* Utility macros to convert IRQ numbers to INT numbers and INT vectors */ |
| #define IRQ_INT( irq ) ( ( ( (irq) - IRQ_PIC_CUTOFF ) ^ 0x70 ) & 0x7f ) |
| |
| /* Other constants */ |
| #define IRQ_MAX 15 |
| #define IRQ_NONE -1U |
| |
| /* Function prototypes |
| */ |
| void send_eoi ( unsigned int irq ); |
| |
| #endif /* PIC8259_H */ |
