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