patch-2.4.20 linux-2.4.20/include/asm-parisc/dma.h

• Lines: 193
• Date: Thu Nov 28 15:53:15 2002
• Orig file: linux-2.4.19/include/asm-parisc/dma.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.19/include/asm-parisc/dma.h linux-2.4.20/include/asm-parisc/dma.h
@@ -0,0 +1,192 @@
+/* $Id: dma.h,v 1.2 1999/04/27 00:46:18 deller Exp $
+ * linux/include/asm/dma.h: Defines for using and allocating dma channels.
+ * Written by Hennus Bergman, 1992.
+ * High DMA channel support & info by Hannu Savolainen
+ * and John Boyd, Nov. 1992.
+ * (c) Copyright 2000, Grant Grundler
+ */
+
+#ifndef _ASM_DMA_H
+#define _ASM_DMA_H
+
+#include <linux/config.h>
+#include <asm/io.h>		/* need byte IO */
+#include <asm/system.h>	
+
+#define dma_outb	outb
+#define dma_inb		inb
+
+/*
+** DMA_CHUNK_SIZE is used by the SCSI mid-layer to break up
+** (or rather not merge) DMA's into managable chunks.
+** On parisc, this is more of the software/tuning constraint
+** rather than the HW. I/O MMU allocation alogorithms can be
+** faster with smaller size is (to some degree).
+*/
+#define DMA_CHUNK_SIZE	(BITS_PER_LONG*PAGE_SIZE)
+
+/* The maximum address that we can perform a DMA transfer to on this platform
+** New dynamic DMA interfaces should obsolete this....
+*/
+#define MAX_DMA_ADDRESS (~0UL)
+
+
+/*
+** We don't have DMA channels... well V-class does but the
+** Dynamic DMA Mapping interface will support them... right? :^)
+** Note: this is not relevant right now for PA-RISC, but we cannot 
+** leave this as undefined because some things (e.g. sound)
+** won't compile :-(
+*/
+#define MAX_DMA_CHANNELS 8
+#define DMA_MODE_READ    1
+#define DMA_MODE_WRITE   2
+#define DMA_AUTOINIT     0x10
+
+/* 8237 DMA controllers */
+#define IO_DMA1_BASE	0x00	/* 8 bit slave DMA, channels 0..3 */
+#define IO_DMA2_BASE	0xC0	/* 16 bit master DMA, ch 4(=slave input)..7 */
+
+/* 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 DMA1_EXT_MODE_REG	(0x400 | DMA1_MODE_REG)
+
+#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 DMA2_EXT_MODE_REG	(0x400 | DMA2_MODE_REG)
+
+extern spinlock_t dma_spin_lock;
+
+static __inline__ unsigned long claim_dma_lock(void)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&dma_spin_lock, flags);
+	return flags;
+}
+
+static __inline__ void release_dma_lock(unsigned long flags)
+{
+	spin_unlock_irqrestore(&dma_spin_lock, flags);
+}
+
+
+/* Get DMA residue count. After a DMA transfer, this
+ * should return zero. Reading this while a DMA transfer is
+ * still in progress will return unpredictable results.
+ * If called before the channel has been used, it may return 1.
+ * Otherwise, it returns the number of _bytes_ left to transfer.
+ *
+ * Assumes DMA flip-flop is clear.
+ */
+static __inline__ int get_dma_residue(unsigned int dmanr)
+{
+	unsigned int io_port = (dmanr<=3)? ((dmanr&3)<<1) + 1 + IO_DMA1_BASE
+					 : ((dmanr&3)<<2) + 2 + IO_DMA2_BASE;
+
+	/* using short to get 16-bit wrap around */
+	unsigned short count;
+
+	count = 1 + dma_inb(io_port);
+	count += dma_inb(io_port) << 8;
+	
+	return (dmanr<=3)? count : (count<<1);
+}
+
+/* enable/disable a specific DMA channel */
+static __inline__ void enable_dma(unsigned int dmanr)
+{
+#ifdef CONFIG_SUPERIO
+	if (dmanr<=3)
+		dma_outb(dmanr,  DMA1_MASK_REG);
+	else
+		dma_outb(dmanr & 3,  DMA2_MASK_REG);
+#endif
+}
+
+static __inline__ void disable_dma(unsigned int dmanr)
+{
+#ifdef CONFIG_SUPERIO
+	if (dmanr<=3)
+		dma_outb(dmanr | 4,  DMA1_MASK_REG);
+	else
+		dma_outb((dmanr & 3) | 4,  DMA2_MASK_REG);
+#endif
+}
+
+/* Clear the 'DMA Pointer Flip Flop'.
+ * Write 0 for LSB/MSB, 1 for MSB/LSB access.
+ * Use this once to initialize the FF to a known state.
+ * After that, keep track of it. :-)
+ * --- In order to do that, the DMA routines below should ---
+ * --- only be used while holding the DMA lock ! ---
+ */
+static __inline__ void clear_dma_ff(unsigned int dmanr)
+{
+}
+
+/* set mode (above) for a specific DMA channel */
+static __inline__ void set_dma_mode(unsigned int dmanr, char mode)
+{
+}
+
+/* Set only the page register bits of the transfer address.
+ * This is used for successive transfers when we know the contents of
+ * the lower 16 bits of the DMA current address register, but a 64k boundary
+ * may have been crossed.
+ */
+static __inline__ void set_dma_page(unsigned int dmanr, char pagenr)
+{
+}
+
+
+/* Set transfer address & page bits for specific DMA channel.
+ * Assumes dma flipflop is clear.
+ */
+static __inline__ void set_dma_addr(unsigned int dmanr, unsigned int a)
+{
+}
+
+
+/* Set transfer size (max 64k for DMA1..3, 128k for DMA5..7) for
+ * a specific DMA channel.
+ * You must ensure the parameters are valid.
+ * NOTE: from a manual: "the number of transfers is one more
+ * than the initial word count"! This is taken into account.
+ * Assumes dma flip-flop is clear.
+ * NOTE 2: "count" represents _bytes_ and must be even for channels 5-7.
+ */
+static __inline__ void set_dma_count(unsigned int dmanr, unsigned int count)
+{
+}
+
+
+
+/* These are in kernel/dma.c: */
+extern int request_dma(unsigned int dmanr, const char * device_id);	/* reserve a DMA channel */
+extern void free_dma(unsigned int dmanr);	/* release it again */
+extern int get_dma_list(char *buf);		/* proc/dma support  */
+
+#ifdef CONFIG_PCI
+extern int isa_dma_bridge_buggy;
+#else
+#define isa_dma_bridge_buggy 	(0)
+#endif
+
+#endif /* _ASM_DMA_H */