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/* MN10300 ISA DMA handlers and definitions
* Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd.
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
#ifndef _ASM_DMA_H
#define _ASM_DMA_H
#include <linux/spinlock.h>
#include <asm/io.h>
#include <linux/delay.h>
#undef MAX_DMA_CHANNELS /* switch off linux/kernel/dma.c */
#define MAX_DMA_ADDRESS 0xbfffffff
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);
/* enable/disable a specific DMA channel */
static inline void enable_dma(unsigned int dmanr)
static inline void disable_dma(unsigned int dmanr)
/* 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)
/* 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)
return 0;
/* These are in kernel/dma.c: */
extern int request_dma(unsigned int dmanr, const char *device_id);
extern void free_dma(unsigned int dmanr);
/* From PCI */
extern int isa_dma_bridge_buggy;
#define isa_dma_bridge_buggy (0)
#endif /* _ASM_DMA_H */