src/drivers/pc80/isa-dma.c

#include <arch/io.h>
#include <pc80/isa-dma.h>

/* DMA controller registers */
#define DMA1_CMD_REG		0x08	/* command register (w) */
#define DMA1_STAT_REG		0x08	/* status register (r) */
#define DMA1_REQ_REG            0x09    /* request register (w) */
#define DMA1_MASK_REG		0x0A	/* single-channel mask (w) */
#define DMA1_MODE_REG		0x0B	/* mode register (w) */
#define DMA1_CLEAR_FF_REG	0x0C	/* clear pointer flip-flop (w) */
#define DMA1_TEMP_REG           0x0D    /* Temporary Register (r) */
#define DMA1_RESET_REG		0x0D	/* Master Clear (w) */
#define DMA1_CLR_MASK_REG       0x0E    /* Clear Mask */
#define DMA1_MASK_ALL_REG       0x0F    /* all-channels mask (w) */

#define DMA2_CMD_REG		0xD0	/* command register (w) */
#define DMA2_STAT_REG		0xD0	/* status register (r) */
#define DMA2_REQ_REG            0xD2    /* request register (w) */
#define DMA2_MASK_REG		0xD4	/* single-channel mask (w) */
#define DMA2_MODE_REG		0xD6	/* mode register (w) */
#define DMA2_CLEAR_FF_REG	0xD8	/* clear pointer flip-flop (w) */
#define DMA2_TEMP_REG           0xDA    /* Temporary Register (r) */
#define DMA2_RESET_REG		0xDA	/* Master Clear (w) */
#define DMA2_CLR_MASK_REG       0xDC    /* Clear Mask */
#define DMA2_MASK_ALL_REG       0xDE    /* all-channels mask (w) */

#define DMA_MODE_READ	0x44	/* I/O to memory, no autoinit, increment, single mode */
#define DMA_MODE_WRITE	0x48	/* memory to I/O, no autoinit, increment, single mode */
#define DMA_MODE_CASCADE 0xC0   /* pass thru DREQ->HRQ, DACK<-HLDA only */

#define DMA_AUTOINIT	0x10


void isa_dma_init(void)
{
	/* slave at 0x00 - 0x0f */
	/* master at 0xc0 - 0xdf */
	/* 0x80 - 0x8f DMA page registers */
	/* DMA: 0x00, 0x02, 0x4, 0x06 base address for DMA channel */
	outb(0, DMA1_RESET_REG);
	outb(0, DMA2_RESET_REG);
	outb(DMA_MODE_CASCADE, DMA2_MODE_REG);
	outb(0, DMA2_MASK_REG);
}