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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/sh/drivers/dma/dma-pvr2.c
Initial import
Diffstat (limited to 'arch/sh/drivers/dma/dma-pvr2.c')
-rw-r--r--arch/sh/drivers/dma/dma-pvr2.c108
1 files changed, 108 insertions, 0 deletions
diff --git a/arch/sh/drivers/dma/dma-pvr2.c b/arch/sh/drivers/dma/dma-pvr2.c
new file mode 100644
index 000000000..706a3434a
--- /dev/null
+++ b/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");