1/* 2 * arch/sh/drivers/dma/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 <mach/sysasic.h> 17#include <mach/dma.h> 18#include <asm/dma.h> 19#include <asm/io.h> 20 21static unsigned int xfer_complete; 22static int count; 23 24static irqreturn_t pvr2_dma_interrupt(int irq, void *dev_id) 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 41static int pvr2_request_dma(struct dma_channel *chan) 42{ 43 if (__raw_readl(PVR2_DMA_MODE) != 0) 44 return -EBUSY; 45 46 __raw_writel(0, PVR2_DMA_LMMODE0); 47 48 return 0; 49} 50 51static int pvr2_get_dma_residue(struct dma_channel *chan) 52{ 53 return xfer_complete == 0; 54} 55 56static 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 __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); 66 67 return 0; 68} 69 70static struct irqaction pvr2_dma_irq = { 71 .name = "pvr2 DMA handler", 72 .handler = pvr2_dma_interrupt, 73 .flags = IRQF_DISABLED, 74}; 75 76static 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 82static 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, 87}; 88 89static 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 97static void __exit pvr2_dma_exit(void) 98{ 99 free_dma(PVR2_CASCADE_CHAN); 100 free_irq(HW_EVENT_PVR2_DMA, 0); 101 unregister_dmac(&pvr2_dma_info); 102} 103 104subsys_initcall(pvr2_dma_init); 105module_exit(pvr2_dma_exit); 106 107MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>"); 108MODULE_DESCRIPTION("NEC PowerVR 2 DMA driver"); 109MODULE_LICENSE("GPL"); 110