USB_MSD.h

00001 /* Copyright (c) 2010-2011 mbed.org, MIT License
00002 *
00003 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
00004 * and associated documentation files (the "Software"), to deal in the Software without
00005 * restriction, including without limitation the rights to use, copy, modify, merge, publish,
00006 * distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the
00007 * Software is furnished to do so, subject to the following conditions:
00008 *
00009 * The above copyright notice and this permission notice shall be included in all copies or
00010 * substantial portions of the Software.
00011 *
00012 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
00013 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
00014 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
00015 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00016 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
00017 */
00018 
00019 #pragma once
00020 
00021 #include "USBDevice.h"
00022 #include "DiskInterface.h"
00023 
00024 // MSC class specific requests
00025 #define MSC_REQUEST_RESET          0xFF
00026 #define MSC_REQUEST_GET_MAX_LUN    0xFE
00027 
00028 /**
00029  * USBMSD2 class: generic class in order to use all kinds of blocks storage chip
00030  *
00031  * Introduction
00032  *
00033  * The USBMSD implements the MSD protocol. It permits to access a memory chip (flash, sdcard,...)
00034  * from a computer over USB. But this class doesn't work standalone, you need to subclass this class
00035  * and define virtual functions which are called in USBMSD.
00036  *
00037  * How to use this class with your chip ?
00038  *
00039  * You have to inherit and define some pure virtual functions (mandatory step):
00040  *   - virtual int disk_read(char * data, int block): function to read a block
00041  *   - virtual int disk_write(const char * data, int block): function to write a block
00042  *   - virtual int disk_initialize(): function to initialize the memory
00043  *   - virtual int disk_sectors(): return the number of blocks
00044  *   - virtual int disk_size(): return the memory size
00045  *   - virtual int disk_status(): return the status of the storage chip (0: OK, 1: not initialized, 2: no medium in the drive, 4: write protection)
00046  *
00047  * All functions names are compatible with the fat filesystem library. So you can imagine using your own class with
00048  * USBMSD and the fat filesystem library in the same program. Just be careful because there are two different parts which
00049  * will access the sd card. You can do a master/slave system using the disk_status method.
00050  *
00051  * Once these functions defined, you can call connect() (at the end of the constructor of your class for instance)
00052  * of USBMSD to connect your mass storage device. connect() will first call disk_status() to test the status of the disk.
00053  * If disk_status() returns 1 (disk not initialized), then disk_initialize() is called. After this step, connect() will collect information
00054  * such as the number of blocks and the memory size.
00055  */
00056 class USB_MSD {
00057 public:
00058     USB_MSD(USBDevice* device, DiskInterface* disk);
00059 
00060     /**
00061     * Connect the USB MSD device. Establish disk initialization before really connect the device.
00062     *
00063     * @returns true if successful
00064     */
00065     bool connect();
00066 
00067     /**
00068     * Disconnect the USB MSD device.
00069     */
00070     void disconnect();
00071     
00072     /**
00073     * Destructor
00074     */
00075     ~USB_MSD();
00076 
00077     bool Request_callback(CONTROL_TRANSFER* transfer);
00078     bool EPBULK_OUT_callback();
00079     bool EPBULK_IN_callback();
00080 
00081 private:
00082     USBDevice* _device;
00083     DiskInterface* _disk;
00084 
00085     // MSC Bulk-only Stage
00086     enum Stage {
00087         READ_CBW,     // wait a CBW
00088         ERROR,        // error
00089         PROCESS_CBW,  // process a CBW request
00090         SEND_CSW,     // send a CSW
00091         WAIT_CSW,     // wait that a CSW has been effectively sent
00092     };
00093 
00094     // Bulk-only CBW
00095     typedef struct {
00096         uint32_t Signature;
00097         uint32_t Tag;
00098         uint32_t DataLength;
00099         uint8_t  Flags;
00100         uint8_t  LUN;
00101         uint8_t  CBLength;
00102         uint8_t  CB[16];
00103     } PACKED CBW;
00104 
00105     // Bulk-only CSW
00106     typedef struct {
00107         uint32_t Signature;
00108         uint32_t Tag;
00109         uint32_t DataResidue;
00110         uint8_t  Status;
00111     } PACKED CSW;
00112 
00113     //state of the bulk-only state machine
00114     Stage stage;
00115 
00116     // current CBW
00117     CBW cbw;
00118 
00119     // CSW which will be sent
00120     CSW csw;
00121 
00122     // addr where will be read or written data
00123     uint32_t addr;
00124 
00125     // length of a reading or writing
00126     uint32_t length;
00127 
00128     // memory OK (after a memoryVerify)
00129     bool memOK;
00130 
00131     // cache in RAM before writing in memory. Useful also to read a block.
00132     uint8_t * page;
00133 
00134     int BlockSize;
00135     uint64_t MemorySize;
00136     uint64_t BlockCount;
00137 
00138     void reset();
00139     void CBWDecode(uint8_t * buf, uint16_t size);
00140     void sendCSW (void);
00141     bool inquiryRequest (void);
00142     bool write (uint8_t * buf, uint16_t size);
00143     bool readFormatCapacity();
00144     bool readCapacity (void);
00145     bool infoTransfer (void);
00146     void memoryRead (void);
00147     bool modeSense6 (void);
00148     void testUnitReady (void);
00149     bool requestSense (void);
00150     void memoryVerify (uint8_t * buf, uint16_t size);
00151     void memoryWrite (uint8_t * buf, uint16_t size);
00152     void fail();
00153 };