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authorSrikant Patnaik2015-01-11 12:28:04 +0530
committerSrikant Patnaik2015-01-11 12:28:04 +0530
commit871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch)
tree8718f573808810c2a1e8cb8fb6ac469093ca2784 /arch/xtensa/include/asm/dma.h
parent9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff)
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Moved, renamed, and deleted files
The original directory structure was scattered and unorganized. Changes are basically to make it look like kernel structure.
Diffstat (limited to 'arch/xtensa/include/asm/dma.h')
-rw-r--r--arch/xtensa/include/asm/dma.h62
1 files changed, 62 insertions, 0 deletions
diff --git a/arch/xtensa/include/asm/dma.h b/arch/xtensa/include/asm/dma.h
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+/*
+ * include/asm-xtensa/dma.h
+ *
+ * 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.
+ *
+ * Copyright (C) 2003 - 2005 Tensilica Inc.
+ */
+
+#ifndef _XTENSA_DMA_H
+#define _XTENSA_DMA_H
+
+#include <asm/io.h> /* need byte IO */
+
+/*
+ * This is only to be defined if we have PC-like DMA.
+ * By default this is not true on an Xtensa processor,
+ * however on boards with a PCI bus, such functionality
+ * might be emulated externally.
+ *
+ * NOTE: there still exists driver code that assumes
+ * this is defined, eg. drivers/sound/soundcard.c (as of 2.4).
+ */
+#define MAX_DMA_CHANNELS 8
+
+/*
+ * The maximum virtual address to which DMA transfers
+ * can be performed on this platform.
+ *
+ * NOTE: This is board (platform) specific, not processor-specific!
+ *
+ * NOTE: This assumes DMA transfers can only be performed on
+ * the section of physical memory contiguously mapped in virtual
+ * space for the kernel. For the Xtensa architecture, this
+ * means the maximum possible size of this DMA area is
+ * the size of the statically mapped kernel segment
+ * (XCHAL_KSEG_{CACHED,BYPASS}_SIZE), ie. 128 MB.
+ *
+ * NOTE: When the entire KSEG area is DMA capable, we subtract
+ * one from the max address so that the virt_to_phys() macro
+ * works correctly on the address (otherwise the address
+ * enters another area, and virt_to_phys() may not return
+ * the value desired).
+ */
+
+#ifndef MAX_DMA_ADDRESS
+#define MAX_DMA_ADDRESS (PAGE_OFFSET + XCHAL_KIO_SIZE - 1)
+#endif
+
+/* Reserve and release a DMA channel */
+extern int request_dma(unsigned int dmanr, const char * device_id);
+extern void free_dma(unsigned int dmanr);
+
+#ifdef CONFIG_PCI
+extern int isa_dma_bridge_buggy;
+#else
+#define isa_dma_bridge_buggy (0)
+#endif
+
+
+#endif