diff options
Diffstat (limited to 'kernel/arch/sh/drivers/dma/dma-pvr2.c')
-rw-r--r-- | kernel/arch/sh/drivers/dma/dma-pvr2.c | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/kernel/arch/sh/drivers/dma/dma-pvr2.c b/kernel/arch/sh/drivers/dma/dma-pvr2.c new file mode 100644 index 000000000..706a3434a --- /dev/null +++ b/kernel/arch/sh/drivers/dma/dma-pvr2.c @@ -0,0 +1,108 @@ +/* + * arch/sh/drivers/dma/dma-pvr2.c + * + * NEC PowerVR 2 (Dreamcast) DMA support + * + * Copyright (C) 2003, 2004 Paul Mundt + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ +#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 irqaction pvr2_dma_irq = { + .name = "pvr2 DMA handler", + .handler = pvr2_dma_interrupt, +}; + +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) +{ + setup_irq(HW_EVENT_PVR2_DMA, &pvr2_dma_irq); + 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"); |