103 lines
2.2 KiB
C
103 lines
2.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* arch/sh/drivers/dma/dma-pvr2.c
|
|
*
|
|
* NEC PowerVR 2 (Dreamcast) DMA support
|
|
*
|
|
* Copyright (C) 2003, 2004 Paul Mundt
|
|
*/
|
|
#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 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)
|
|
{
|
|
if (request_irq(HW_EVENT_PVR2_DMA, pvr2_dma_interrupt, 0,
|
|
"pvr2 DMA handler", NULL))
|
|
pr_err("Failed to register pvr2 DMA handler interrupt\n");
|
|
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 v2");
|