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https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
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0d831770b1
This extends the current SH DMA API somewhat to support a proper virtual channel abstraction, and also works to represent this through the driver model by giving each DMAC its own platform device. There's also a few other minor changes to support a few new CPU subtypes, and make TEI generation for the SH DMAC configurable. Signed-off-by: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
107 lines
2.7 KiB
C
107 lines
2.7 KiB
C
/*
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* arch/sh/drivers/dma/dma-isa.c
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*
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* Generic ISA DMA wrapper for SH DMA API
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*
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* Copyright (C) 2003, 2004 Paul Mundt
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <asm/dma.h>
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/*
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* This implements a small wrapper set to make code using the old ISA DMA API
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* work with the SH DMA API. Since most of the work in the new API happens
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* at ops->xfer() time, we simply use the various set_dma_xxx() routines to
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* fill in per-channel info, and then hand hand this off to ops->xfer() at
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* enable_dma() time.
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*
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* For channels that are doing on-demand data transfer via cascading, the
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* channel itself will still need to be configured through the new API. As
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* such, this code is meant for only the simplest of tasks (and shouldn't be
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* used in any new drivers at all).
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*
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* NOTE: ops->xfer() is the preferred way of doing things. However, there
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* are some users of the ISA DMA API that exist in common code that we
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* don't necessarily want to go out of our way to break, so we still
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* allow for some compatability at that level. Any new code is strongly
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* advised to run far away from the ISA DMA API and use the SH DMA API
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* directly.
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*/
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unsigned long claim_dma_lock(void)
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{
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unsigned long flags;
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spin_lock_irqsave(&dma_spin_lock, flags);
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return flags;
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}
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EXPORT_SYMBOL(claim_dma_lock);
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void release_dma_lock(unsigned long flags)
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{
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spin_unlock_irqrestore(&dma_spin_lock, flags);
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}
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EXPORT_SYMBOL(release_dma_lock);
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void disable_dma(unsigned int chan)
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{
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/* Nothing */
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}
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EXPORT_SYMBOL(disable_dma);
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void enable_dma(unsigned int chan)
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{
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struct dma_info *info = get_dma_info(chan);
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struct dma_channel *channel = &info->channels[chan];
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info->ops->xfer(channel);
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}
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EXPORT_SYMBOL(enable_dma);
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void clear_dma_ff(unsigned int chan)
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{
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/* Nothing */
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}
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EXPORT_SYMBOL(clear_dma_ff);
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void set_dma_mode(unsigned int chan, char mode)
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{
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struct dma_info *info = get_dma_info(chan);
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struct dma_channel *channel = &info->channels[chan];
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channel->mode = mode;
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}
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EXPORT_SYMBOL(set_dma_mode);
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void set_dma_addr(unsigned int chan, unsigned int addr)
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{
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struct dma_info *info = get_dma_info(chan);
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struct dma_channel *channel = &info->channels[chan];
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/*
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* Single address mode is the only thing supported through
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* this interface.
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*/
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if ((channel->mode & DMA_MODE_MASK) == DMA_MODE_READ) {
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channel->sar = addr;
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} else {
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channel->dar = addr;
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}
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}
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EXPORT_SYMBOL(set_dma_addr);
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void set_dma_count(unsigned int chan, unsigned int count)
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{
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struct dma_info *info = get_dma_info(chan);
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struct dma_channel *channel = &info->channels[chan];
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channel->count = count;
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}
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EXPORT_SYMBOL(set_dma_count);
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