Merge branch 'akpm'
[linux-2.6/next.git] / arch / sh / drivers / dma / dma-pvr2.c
blob3cee58e7f1e5ff0677a1b003030d3fe19e3ffa09
1 /*
2 * arch/sh/drivers/dma/dma-pvr2.c
4 * NEC PowerVR 2 (Dreamcast) DMA support
6 * Copyright (C) 2003, 2004 Paul Mundt
8 * This file is subject to the terms and conditions of the GNU General Public
9 * License. See the file "COPYING" in the main directory of this archive
10 * for more details.
12 #include <linux/init.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/interrupt.h>
16 #include <mach/sysasic.h>
17 #include <mach/dma.h>
18 #include <asm/dma.h>
19 #include <asm/io.h>
21 static unsigned int xfer_complete;
22 static int count;
24 static irqreturn_t pvr2_dma_interrupt(int irq, void *dev_id)
26 if (get_dma_residue(PVR2_CASCADE_CHAN)) {
27 printk(KERN_WARNING "DMA: SH DMAC did not complete transfer "
28 "on channel %d, waiting..\n", PVR2_CASCADE_CHAN);
29 dma_wait_for_completion(PVR2_CASCADE_CHAN);
32 if (count++ < 10)
33 pr_debug("Got a pvr2 dma interrupt for channel %d\n",
34 irq - HW_EVENT_PVR2_DMA);
36 xfer_complete = 1;
38 return IRQ_HANDLED;
41 static int pvr2_request_dma(struct dma_channel *chan)
43 if (__raw_readl(PVR2_DMA_MODE) != 0)
44 return -EBUSY;
46 __raw_writel(0, PVR2_DMA_LMMODE0);
48 return 0;
51 static int pvr2_get_dma_residue(struct dma_channel *chan)
53 return xfer_complete == 0;
56 static int pvr2_xfer_dma(struct dma_channel *chan)
58 if (chan->sar || !chan->dar)
59 return -EINVAL;
61 xfer_complete = 0;
63 __raw_writel(chan->dar, PVR2_DMA_ADDR);
64 __raw_writel(chan->count, PVR2_DMA_COUNT);
65 __raw_writel(chan->mode & DMA_MODE_MASK, PVR2_DMA_MODE);
67 return 0;
70 static struct irqaction pvr2_dma_irq = {
71 .name = "pvr2 DMA handler",
72 .handler = pvr2_dma_interrupt,
73 .flags = IRQF_DISABLED,
76 static struct dma_ops pvr2_dma_ops = {
77 .request = pvr2_request_dma,
78 .get_residue = pvr2_get_dma_residue,
79 .xfer = pvr2_xfer_dma,
82 static struct dma_info pvr2_dma_info = {
83 .name = "pvr2_dmac",
84 .nr_channels = 1,
85 .ops = &pvr2_dma_ops,
86 .flags = DMAC_CHANNELS_TEI_CAPABLE,
89 static int __init pvr2_dma_init(void)
91 setup_irq(HW_EVENT_PVR2_DMA, &pvr2_dma_irq);
92 request_dma(PVR2_CASCADE_CHAN, "pvr2 cascade");
94 return register_dmac(&pvr2_dma_info);
97 static void __exit pvr2_dma_exit(void)
99 free_dma(PVR2_CASCADE_CHAN);
100 free_irq(HW_EVENT_PVR2_DMA, 0);
101 unregister_dmac(&pvr2_dma_info);
104 subsys_initcall(pvr2_dma_init);
105 module_exit(pvr2_dma_exit);
107 MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>");
108 MODULE_DESCRIPTION("NEC PowerVR 2 DMA driver");
109 MODULE_LICENSE("GPL");