--- /dev/null
+/*
+ Interface for DMA routines on DOS
+ Copyright (C) 1999 by Andrew Zabolotny, <bit@eltech.ru>
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Library General Public
+ License as published by the Free Software Foundation; either
+ version 2 of the License, or (at your option) any later version.
+
+ This library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public
+ License along with this library; if not, write to the Free
+ Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#ifndef __DOSDMA_H__
+#define __DOSDMA_H__
+
+#include <pc.h>
+
+#define DMA1_BASE 0x00 /* 8 bit slave DMA, channels 0..3 */
+#define DMA2_BASE 0xC0 /* 16 bit master DMA, ch 4(=slave input)..7 */
+
+#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_ADDR_0 0x00 /* DMA address registers */
+#define DMA_ADDR_1 0x02
+#define DMA_ADDR_2 0x04
+#define DMA_ADDR_3 0x06
+#define DMA_ADDR_4 0xC0
+#define DMA_ADDR_5 0xC4
+#define DMA_ADDR_6 0xC8
+#define DMA_ADDR_7 0xCC
+
+#define DMA_SIZE_0 0x01 /* DMA transfer size registers */
+#define DMA_SIZE_1 0x03
+#define DMA_SIZE_2 0x05
+#define DMA_SIZE_3 0x07
+#define DMA_SIZE_4 0xC2
+#define DMA_SIZE_5 0xC6
+#define DMA_SIZE_6 0xCA
+#define DMA_SIZE_7 0xCE
+
+#define DMA_PAGE_0 0x87 /* DMA page registers */
+#define DMA_PAGE_1 0x83
+#define DMA_PAGE_2 0x81
+#define DMA_PAGE_3 0x82
+#define DMA_PAGE_5 0x8B
+#define DMA_PAGE_6 0x89
+#define DMA_PAGE_7 0x8A
+
+#define DMA_MODE_AUTOINIT 0x10 /* Auto-init mode bit */
+#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 */
+
+/* Indexable specific DMA registers */
+typedef struct __dma_regs_s {
+ unsigned char addr; /* DMA transfer address register */
+ unsigned char page; /* DMA page register */
+ unsigned char size; /* DMA transfer size register */
+ unsigned char mask; /* DMA mask/unmask register */
+ unsigned char flip; /* DMA flip-flop reset register */
+ unsigned char mode; /* DMA mode register */
+} __dma_regs;
+
+extern __dma_regs dma[8];
+
+/* Enable a specific DMA channel */
+static inline void dma_enable(unsigned int channel)
+{
+ outportb(dma[channel].mask, channel & 3);
+}
+
+/* Disable a specific DMA channel */
+static inline void dma_disable(unsigned int channel)
+{
+ outportb(dma[channel].mask, (channel & 3) | 0x04);
+}
+
+/* Clear the 'DMA Flip Flop' flag */
+static inline void dma_clear_ff(unsigned int channel)
+{
+ outportb(dma[channel].flip, 0);
+}
+
+/* Set mode for a specific DMA channel */
+static inline void dma_set_mode(unsigned int channel, char mode)
+{
+ outportb(dma[channel].mode, mode | (channel & 3));
+}
+
+/* Set DMA page register */
+static inline void dma_set_page(unsigned int channel, char page)
+{
+ if (channel > 3)
+ page &= 0xfe;
+ outportb(dma[channel].page, page);
+}
+
+/*
+ Set transfer address & page bits for specific DMA channel.
+ Assumes dma flipflop is clear.
+*/
+static inline void dma_set_addr(unsigned int channel, unsigned int address)
+{
+ unsigned char dma_reg = dma[channel].addr;
+ dma_set_page(channel, address >> 16);
+ if (channel <= 3) {
+ outportb(dma_reg, (address) & 0xff);
+ outportb(dma_reg, (address >> 8) & 0xff);
+ } else {
+ outportb(dma_reg, (address >> 1) & 0xff);
+ outportb(dma_reg, (address >> 9) & 0xff);
+ }
+}
+
+/*
+ Set transfer size for a specific DMA channel.
+ Assumes dma flip-flop is clear.
+*/
+static inline void dma_set_count(unsigned int channel, unsigned int count)
+{
+ unsigned char dma_reg = dma[channel].size;
+ count--; /* number of DMA transfers is bigger by one */
+ if (channel > 3)
+ count >>= 1;
+ outportb(dma_reg, (count) & 0xff);
+ outportb(dma_reg, (count >> 8) & 0xff);
+}
+
+/*
+ Query the number of bytes left to transfer.
+ Assumes DMA flip-flop is clear.
+*/
+static inline int dma_get_count(unsigned int channel)
+{
+ unsigned char dma_reg = dma[channel].size;
+
+ /* using short to get 16-bit wrap around */
+ unsigned short count;
+ count = inportb(dma_reg);
+ count |= inportb(dma_reg) << 8;
+ count++;
+ return (channel <= 3) ? count : (count << 1);
+}
+
+typedef struct dma_buffer_s {
+ unsigned char *linear; /* Linear address */
+ unsigned long physical; /* Physical address */
+ unsigned long size; /* Buffer size */
+ unsigned short selector; /* The selector assigned to this memory */
+ unsigned char channel; /* The DMA channel */
+} dma_buffer;
+
+/* Allocate a block of memory suitable for using as a DMA buffer */
+extern dma_buffer *dma_allocate(unsigned int channel, unsigned int size);
+/* Deallocate a DMA buffer */
+extern void dma_free(dma_buffer * buffer);
+/* Start DMA transfer to or from given buffer */
+extern void dma_start(dma_buffer * buffer, unsigned long count,
+ unsigned char mode);
+
+#endif /* __DOSDMA_H__ */
+
+/* ex:set ts=4: */
projects / dosdemo / blobdiff