linux-libre/arch/mn10300/include/asm/dma.h

/* 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 */

#ifdef CONFIG_PCI
extern int isa_dma_bridge_buggy;
#else
#define isa_dma_bridge_buggy 	(0)
#endif

#endif /* _ASM_DMA_H */