iokit/IOKit/IODeviceMemory.h

   1 /*
   2  * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * Copyright (c) 1998 Apple Computer, Inc.  All rights reserved.
  24  *
  25  * HISTORY
  26  *
  27  */
  28
  29 #ifndef _IOKIT_IODEVICEMEMORY_H
  30 #define _IOKIT_IODEVICEMEMORY_H
  31
  32 #include <IOKit/IOMemoryDescriptor.h>
  33
  34 /*! @class IODeviceMemory
  35     @abstract An IOMemoryDescriptor used for device physical memory ranges.
  36     @discussion The IODeviceMemory class is a simple subclass of IOMemoryDescriptor that uses its methods to describe a single range of physical memory on a device. IODeviceMemory objects are usually looked up with IOService or IOPCIDevice accessors, and are created by memory-mapped bus families. IODeviceMemory implements only some factory methods in addition to the methods of IOMemoryDescriptor.
  37 */
  38
  39 class IODeviceMemory : public IOMemoryDescriptor
  40 {
  41     OSDeclareDefaultStructors(IODeviceMemory)
  42
  43 public:
  44
  45 /*! @struct InitElement
  46     @field start First physical address in the range.
  47     @field length Length of the range.
  48     @field tag 32-bit value not interpreted by IODeviceMemory or IOMemoryDescriptor, for use by the bus family. */
  49
  50     struct InitElement {
  51         IOPhysicalAddress       start;
  52         IOPhysicalLength        length;
  53         IOOptionBits            tag;
  54     };
  55
  56 /*! @function arrayFromList
  57     @abstract Constructs an OSArray of IODeviceMemory instances, each describing one physical range, and a tag value.
  58     @discussion This method creates IODeviceMemory instances for each physical range passed in an IODeviceMemory::InitElement array. Each element consists of a physical address, length and tag value for the IODeviceMemory. The instances are returned as a created OSArray.
  59     @param list An array of IODeviceMemory::InitElement structures.
  60     @param count The number of elements in the list.
  61     @result Returns a created OSArray of IODeviceMemory objects, to be released by the caller, or zero on failure. */
  62
  63     static OSArray *            arrayFromList(
  64         InitElement             list[],
  65         IOItemCount             count );
  66
  67 /*! @function withRange
  68     @abstract Constructs an IODeviceMemory instance, describing one physical range.
  69     @discussion This method creates an IODeviceMemory instance for one physical range passed as a physical address and length. It just calls IOMemoryDescriptor::withPhysicalAddress.
  70     @param address The physical address of the first byte in the memory.
  71     @param withLength The length of memory.
  72     @result Returns the created IODeviceMemory on success, to be released by the caller, or zero on failure. */
  73
  74     static IODeviceMemory *     withRange(
  75         IOPhysicalAddress       start,
  76         IOPhysicalLength        length );
  77
  78 /*! @function withSubRange
  79     @abstract Constructs an IODeviceMemory instance, describing a subset of an existing IODeviceMemory range.
  80     @discussion This method creates an IODeviceMemory instance for a subset of an existing IODeviceMemory range, passed as a physical address offset and length. It just calls IOMemoryDescriptor::withSubRange.
  81     @param of The parent IODeviceMemory of which a subrange is to be used for the new descriptor, which will be retained by the subrange IODeviceMemory.
  82     @param offset A byte offset into the parent's memory.
  83     @param length The length of the subrange.
  84     @result Returns the created IODeviceMemory on success, to be released by the caller, or zero on failure. */
  85
  86     static IODeviceMemory *     withSubRange(
  87         IODeviceMemory *        of,
  88         IOPhysicalAddress       offset,
  89         IOPhysicalLength        length );
  90 };
  91
  92 #endif /* ! _IOKIT_IODEVICEMEMORY_H */