arch/x86/include/asm/i8259.h

/*
 * (C) Copyright 2002
 * Daniel Engström, Omicron Ceti AB, daniel@omicron.se.
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

/* i8259.h i8259 PIC Registers */

#ifndef _ASMI386_I8259_H_
#define _ASMI386_I8959_H_

/* PIC I/O mapped registers */
#define IRR		0x0	/* Interrupt Request Register */
#define ISR		0x0	/* In-Service Register */
#define ICW1		0x0	/* Initialization Control Word 1 */
#define OCW2		0x0	/* Operation Control Word 2 */
#define OCW3		0x0	/* Operation Control Word 3 */
#define ICW2		0x1	/* Initialization Control Word 2 */
#define ICW3		0x1	/* Initialization Control Word 3 */
#define ICW4		0x1	/* Initialization Control Word 4 */
#define IMR		0x1	/* Interrupt Mask Register */

/* IRR, IMR, ISR and ICW3 bits */
#define	IR7		0x80	/* IR7 */
#define	IR6		0x40	/* IR6 */
#define	IR5		0x20	/* IR5 */
#define	IR4		0x10	/* IR4 */
#define	IR3		0x08	/* IR3 */
#define	IR2		0x04	/* IR2 */
#define	IR1		0x02	/* IR1 */
#define	IR0		0x01	/* IR0 */

/* SEOI bits */
#define	SEOI_IR7	0x07	/* IR7 */
#define	SEOI_IR6	0x06	/* IR6 */
#define	SEOI_IR5	0x05	/* IR5 */
#define	SEOI_IR4	0x04	/* IR4 */
#define	SEOI_IR3	0x03	/* IR3 */
#define	SEOI_IR2	0x02	/* IR2 */
#define	SEOI_IR1	0x01	/* IR1 */
#define	SEOI_IR0	0x00	/* IR0 */

/* OCW2 bits */
#define OCW2_RCLR	0x00	/* Rotate/clear */
#define OCW2_NEOI	0x20	/* Non specific EOI */
#define OCW2_NOP	0x40	/* NOP */
#define OCW2_SEOI	0x60	/* Specific EOI */
#define OCW2_RSET	0x80	/* Rotate/set */
#define OCW2_REOI	0xa0	/* Rotate on non specific EOI */
#define OCW2_PSET	0xc0	/* Priority Set Command */
#define OCW2_RSEOI	0xe0	/* Rotate on specific EOI */

/* ICW1 bits */
#define ICW1_SEL	0x10	/* Select ICW1 */
#define ICW1_LTIM	0x08	/* Level-Triggered Interrupt Mode */
#define ICW1_ADI	0x04	/* Address Interval */
#define ICW1_SNGL	0x02	/* Single PIC */
#define ICW1_EICW4	0x01	/* Expect initilization ICW4 */

/*
 * ICW2 is the starting vector number
 *
 * ICW2 is bit-mask of present slaves for a master device,
 * or the slave ID for a slave device
 */

/* ICW4 bits */
#define ICW4_AEOI	0x02	/* Automatic EOI Mode */
#define ICW4_PM		0x01	/* Microprocessor Mode */

#define ELCR1		0x4d0
#define ELCR2		0x4d1

int i8259_init(void);

#endif /* _ASMI386_I8959_H_ */