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author | Paul Mundt <lethal@linux-sh.org> | 2006-09-27 16:53:40 +0900 |
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committer | Paul Mundt <lethal@linux-sh.org> | 2006-09-27 16:53:40 +0900 |
commit | e2d1864da5bfa419a108f42c0615f69432b1b876 (patch) | |
tree | 2ebd838b7b6cca8d5db7d2991797a5bc9ae1d1ab /arch/sh/drivers | |
parent | ade2b3f6ed199dc4a7a0be53edf20f9399023640 (diff) | |
download | linux-3.10-e2d1864da5bfa419a108f42c0615f69432b1b876.tar.gz linux-3.10-e2d1864da5bfa419a108f42c0615f69432b1b876.tar.bz2 linux-3.10-e2d1864da5bfa419a108f42c0615f69432b1b876.zip |
sh: G2 DMA IRQ and residue sampling.
This fixes a long-standing FIXME for G2 DMA, where we finally
wire up the IRQ handler and allow for sampling remaining bytes
while in-flight.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'arch/sh/drivers')
-rw-r--r-- | arch/sh/drivers/dma/dma-g2.c | 54 |
1 files changed, 41 insertions, 13 deletions
diff --git a/arch/sh/drivers/dma/dma-g2.c b/arch/sh/drivers/dma/dma-g2.c index 0f866f8789f..9cb07092418 100644 --- a/arch/sh/drivers/dma/dma-g2.c +++ b/arch/sh/drivers/dma/dma-g2.c @@ -3,7 +3,7 @@ * * G2 bus DMA support * - * Copyright (C) 2003, 2004 Paul Mundt + * Copyright (C) 2003 - 2006 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 @@ -13,7 +13,7 @@ #include <linux/kernel.h> #include <linux/module.h> #include <linux/interrupt.h> - +#include <asm/cacheflush.h> #include <asm/mach/sysasic.h> #include <asm/mach/dma.h> #include <asm/dma.h> @@ -47,17 +47,31 @@ struct g2_dma_info { static volatile struct g2_dma_info *g2_dma = (volatile struct g2_dma_info *)0xa05f7800; +#define g2_bytes_remaining(i) \ + ((g2_dma->channel[i].size - \ + g2_dma->status[i].size) & 0x0fffffff) + static irqreturn_t g2_dma_interrupt(int irq, void *dev_id, struct pt_regs *regs) { - /* FIXME: Do some meaningful completion work here.. */ - return IRQ_HANDLED; -} + int i; -static struct irqaction g2_dma_irq = { - .name = "g2 DMA handler", - .handler = g2_dma_interrupt, - .flags = IRQF_DISABLED, -}; + for (i = 0; i < G2_NR_DMA_CHANNELS; i++) { + if (g2_dma->status[i].status & 0x20000000) { + unsigned int bytes = g2_bytes_remaining(i); + + if (likely(bytes == 0)) { + struct dma_info *info = dev_id; + struct dma_channel *chan = info->channels + i; + + wake_up(&chan->wait_queue); + + return IRQ_HANDLED; + } + } + } + + return IRQ_NONE; +} static int g2_enable_dma(struct dma_channel *chan) { @@ -135,8 +149,14 @@ static int g2_xfer_dma(struct dma_channel *chan) return 0; } +static int g2_get_residue(struct dma_channel *chan) +{ + return g2_bytes_remaining(chan->chan); +} + static struct dma_ops g2_dma_ops = { .xfer = g2_xfer_dma, + .get_residue = g2_get_residue, }; static struct dma_info g2_dma_info = { @@ -148,13 +168,22 @@ static struct dma_info g2_dma_info = { static int __init g2_dma_init(void) { - setup_irq(HW_EVENT_G2_DMA, &g2_dma_irq); + int ret; + + ret = request_irq(HW_EVENT_G2_DMA, g2_dma_interrupt, IRQF_DISABLED, + "g2 DMA handler", &g2_dma_info); + if (unlikely(ret)) + return -EINVAL; /* Magic */ g2_dma->wait_state = 27; g2_dma->magic = 0x4659404f; - return register_dmac(&g2_dma_info); + ret = register_dmac(&g2_dma_info); + if (unlikely(ret != 0)) + free_irq(HW_EVENT_G2_DMA, 0); + + return ret; } static void __exit g2_dma_exit(void) @@ -169,4 +198,3 @@ module_exit(g2_dma_exit); MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>"); MODULE_DESCRIPTION("G2 bus DMA driver"); MODULE_LICENSE("GPL"); - |