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/*
* arch/sh/drivers/dma/dma-pvr2.c
*
* NEC PowerVR 2 (Dreamcast) DMA support
*
* 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/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <mach/sysasic.h>
#include <mach/dma.h>
#include <asm/dma.h>
#include <asm/io.h>
static unsigned int xfer_complete;
static int count;
static irqreturn_t pvr2_dma_interrupt(int irq, void *dev_id)
{
if (get_dma_residue(PVR2_CASCADE_CHAN)) {
printk(KERN_WARNING "DMA: SH DMAC did not complete transfer "
"on channel %d, waiting..\n", PVR2_CASCADE_CHAN);
dma_wait_for_completion(PVR2_CASCADE_CHAN);
}
if (count++ < 10)
pr_debug("Got a pvr2 dma interrupt for channel %d\n",
irq - HW_EVENT_PVR2_DMA);
xfer_complete = 1;
return IRQ_HANDLED;
}
static int pvr2_request_dma(struct dma_channel *chan)
{
if (__raw_readl(PVR2_DMA_MODE) != 0)
return -EBUSY;
__raw_writel(0, PVR2_DMA_LMMODE0);
return 0;
}
static int pvr2_get_dma_residue(struct dma_channel *chan)
{
return xfer_complete == 0;
}
static int pvr2_xfer_dma(struct dma_channel *chan)
{
if (chan->sar || !chan->dar)
return -EINVAL;
xfer_complete = 0;
__raw_writel(chan->dar, PVR2_DMA_ADDR);
__raw_writel(chan->count, PVR2_DMA_COUNT);
__raw_writel(chan->mode & DMA_MODE_MASK, PVR2_DMA_MODE);
return 0;
}
static struct irqaction pvr2_dma_irq = {
.name = "pvr2 DMA handler",
.handler = pvr2_dma_interrupt,
.flags = IRQF_DISABLED,
};
static struct dma_ops pvr2_dma_ops = {
.request = pvr2_request_dma,
.get_residue = pvr2_get_dma_residue,
.xfer = pvr2_xfer_dma,
};
static struct dma_info pvr2_dma_info = {
.name = "pvr2_dmac",
.nr_channels = 1,
.ops = &pvr2_dma_ops,
.flags = DMAC_CHANNELS_TEI_CAPABLE,
};
static int __init pvr2_dma_init(void)
{
setup_irq(HW_EVENT_PVR2_DMA, &pvr2_dma_irq);
request_dma(PVR2_CASCADE_CHAN, "pvr2 cascade");
return register_dmac(&pvr2_dma_info);
}
static void __exit pvr2_dma_exit(void)
{
free_dma(PVR2_CASCADE_CHAN);
free_irq(HW_EVENT_PVR2_DMA, 0);
unregister_dmac(&pvr2_dma_info);
}
subsys_initcall(pvr2_dma_init);
module_exit(pvr2_dma_exit);
MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>");
MODULE_DESCRIPTION("NEC PowerVR 2 DMA driver");
MODULE_LICENSE("GPL");
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