linux/arch/sh/drivers/dma/dma-isa.c

107 lines
2.7 KiB
C

/*
* arch/sh/drivers/dma/dma-isa.c
*
* Generic ISA DMA wrapper for SH DMA API
*
* Copyright (C) 2003, 2004 Paul Mundt
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <asm/dma.h>
/*
* This implements a small wrapper set to make code using the old ISA DMA API
* work with the SH DMA API. Since most of the work in the new API happens
* at ops->xfer() time, we simply use the various set_dma_xxx() routines to
* fill in per-channel info, and then hand hand this off to ops->xfer() at
* enable_dma() time.
*
* For channels that are doing on-demand data transfer via cascading, the
* channel itself will still need to be configured through the new API. As
* such, this code is meant for only the simplest of tasks (and shouldn't be
* used in any new drivers at all).
*
* NOTE: ops->xfer() is the preferred way of doing things. However, there
* are some users of the ISA DMA API that exist in common code that we
* don't necessarily want to go out of our way to break, so we still
* allow for some compatibility at that level. Any new code is strongly
* advised to run far away from the ISA DMA API and use the SH DMA API
* directly.
*/
unsigned long claim_dma_lock(void)
{
unsigned long flags;
spin_lock_irqsave(&dma_spin_lock, flags);
return flags;
}
EXPORT_SYMBOL(claim_dma_lock);
void release_dma_lock(unsigned long flags)
{
spin_unlock_irqrestore(&dma_spin_lock, flags);
}
EXPORT_SYMBOL(release_dma_lock);
void disable_dma(unsigned int chan)
{
/* Nothing */
}
EXPORT_SYMBOL(disable_dma);
void enable_dma(unsigned int chan)
{
struct dma_info *info = get_dma_info(chan);
struct dma_channel *channel = &info->channels[chan];
info->ops->xfer(channel);
}
EXPORT_SYMBOL(enable_dma);
void clear_dma_ff(unsigned int chan)
{
/* Nothing */
}
EXPORT_SYMBOL(clear_dma_ff);
void set_dma_mode(unsigned int chan, char mode)
{
struct dma_info *info = get_dma_info(chan);
struct dma_channel *channel = &info->channels[chan];
channel->mode = mode;
}
EXPORT_SYMBOL(set_dma_mode);
void set_dma_addr(unsigned int chan, unsigned int addr)
{
struct dma_info *info = get_dma_info(chan);
struct dma_channel *channel = &info->channels[chan];
/*
* Single address mode is the only thing supported through
* this interface.
*/
if ((channel->mode & DMA_MODE_MASK) == DMA_MODE_READ) {
channel->sar = addr;
} else {
channel->dar = addr;
}
}
EXPORT_SYMBOL(set_dma_addr);
void set_dma_count(unsigned int chan, unsigned int count)
{
struct dma_info *info = get_dma_info(chan);
struct dma_channel *channel = &info->channels[chan];
channel->count = count;
}
EXPORT_SYMBOL(set_dma_count);