| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * arch/sh/boards/dreamcast/dma-pvr2.c |
| 3 | * |
| 4 | * NEC PowerVR 2 (Dreamcast) DMA support |
| 5 | * |
| 6 | * Copyright (C) 2003, 2004 Paul Mundt |
| 7 | * |
| 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. |
| 11 | */ |
| 12 | #include <linux/init.h> |
| 13 | #include <linux/kernel.h> |
| 14 | #include <linux/module.h> |
| 15 | #include <linux/interrupt.h> |
| 16 | #include <asm/mach/sysasic.h> |
| 17 | #include <asm/mach/dma.h> |
| 18 | #include <asm/dma.h> |
| 19 | #include <asm/io.h> |
| 20 | |
| 21 | static unsigned int xfer_complete = 0; |
| 22 | static int count = 0; |
| 23 | |
| 24 | static irqreturn_t pvr2_dma_interrupt(int irq, void *dev_id, struct pt_regs *regs) |
| 25 | { |
| 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); |
| 30 | } |
| 31 | |
| 32 | if (count++ < 10) |
| 33 | pr_debug("Got a pvr2 dma interrupt for channel %d\n", |
| 34 | irq - HW_EVENT_PVR2_DMA); |
| 35 | |
| 36 | xfer_complete = 1; |
| 37 | |
| 38 | return IRQ_HANDLED; |
| 39 | } |
| 40 | |
| 41 | static int pvr2_request_dma(struct dma_channel *chan) |
| 42 | { |
| 43 | if (ctrl_inl(PVR2_DMA_MODE) != 0) |
| 44 | return -EBUSY; |
| 45 | |
| 46 | ctrl_outl(0, PVR2_DMA_LMMODE0); |
| 47 | |
| 48 | return 0; |
| 49 | } |
| 50 | |
| 51 | static int pvr2_get_dma_residue(struct dma_channel *chan) |
| 52 | { |
| 53 | return xfer_complete == 0; |
| 54 | } |
| 55 | |
| 56 | static int pvr2_xfer_dma(struct dma_channel *chan) |
| 57 | { |
| 58 | if (chan->sar || !chan->dar) |
| 59 | return -EINVAL; |
| 60 | |
| 61 | xfer_complete = 0; |
| 62 | |
| 63 | ctrl_outl(chan->dar, PVR2_DMA_ADDR); |
| 64 | ctrl_outl(chan->count, PVR2_DMA_COUNT); |
| 65 | ctrl_outl(chan->mode & DMA_MODE_MASK, PVR2_DMA_MODE); |
| 66 | |
| 67 | return 0; |
| 68 | } |
| 69 | |
| 70 | static struct irqaction pvr2_dma_irq = { |
| 71 | .name = "pvr2 DMA handler", |
| 72 | .handler = pvr2_dma_interrupt, |
| 73 | .flags = SA_INTERRUPT, |
| 74 | }; |
| 75 | |
| 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, |
| 80 | }; |
| 81 | |
| 82 | static struct dma_info pvr2_dma_info = { |
| 83 | .name = "PowerVR 2 DMA", |
| 84 | .nr_channels = 1, |
| 85 | .ops = &pvr2_dma_ops, |
| 86 | .flags = DMAC_CHANNELS_TEI_CAPABLE, |
| 87 | }; |
| 88 | |
| 89 | static int __init pvr2_dma_init(void) |
| 90 | { |
| 91 | setup_irq(HW_EVENT_PVR2_DMA, &pvr2_dma_irq); |
| 92 | request_dma(PVR2_CASCADE_CHAN, "pvr2 cascade"); |
| 93 | |
| 94 | return register_dmac(&pvr2_dma_info); |
| 95 | } |
| 96 | |
| 97 | static void __exit pvr2_dma_exit(void) |
| 98 | { |
| 99 | free_dma(PVR2_CASCADE_CHAN); |
| 100 | free_irq(HW_EVENT_PVR2_DMA, 0); |
| 101 | } |
| 102 | |
| 103 | subsys_initcall(pvr2_dma_init); |
| 104 | module_exit(pvr2_dma_exit); |
| 105 | |
| 106 | MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>"); |
| 107 | MODULE_DESCRIPTION("NEC PowerVR 2 DMA driver"); |
| 108 | MODULE_LICENSE("GPL"); |
| 109 | |