main.c

AVR单片机模拟USB实现CDC类串行口

/* Name: main.c
 * Project: AVR USB driver for CDC interface on Low-Speed USB
 * Author: Osamu Tamura
 * Creation Date: 2006-05-12
 * Tabsize: 4
 * Copyright: (c) 2006 by Recursion Co., Ltd.
 * License: Proprietary, free under certain conditions. See Documentation.
 *
 * 2006-07-08   removed zero-sized receive block
 * 2006-07-08   adapted to higher baud rate by T.Kitazawa
 *
 */

#include <string.h>
#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/pgmspace.h>
#include <avr/wdt.h>

#include "usbdrv.h"
#include "oddebug.h"
#include "uart.h"


#if UART_CFG_HAVE_USART
#define HW_CDC_BULK_OUT_SIZE     8
#else
#define HW_CDC_BULK_OUT_SIZE     1
#endif
#define HW_CDC_BULK_IN_SIZE      8
/* Size of bulk transfer packets. The standard demands 8 bytes, but we may
 * be better off with less. Try smaller values if the communication hangs.
 */

enum {
    SEND_ENCAPSULATED_COMMAND = 0,
    GET_ENCAPSULATED_RESPONSE,
    SET_COMM_FEATURE,
    GET_COMM_FEATURE,
    CLEAR_COMM_FEATURE,
    SET_LINE_CODING = 0x20,
    GET_LINE_CODING,
    SET_CONTROL_LINE_STATE,
    SEND_BREAK
};


static PROGMEM char deviceDescrCDC[] = {    /* USB device descriptor */
    18,         /* sizeof(usbDescriptorDevice): length of descriptor in bytes */
    USBDESCR_DEVICE,        /* descriptor type */
    0x01, 0x01,             /* USB version supported */
    0x02,                   /* device class: CDC */
    0,                      /* subclass */
    0,                      /* protocol */
    8,                      /* max packet size */
    USB_CFG_VENDOR_ID,      /* 2 bytes */
    0xe1, 0x05,             /* 2 bytes: shared PID for CDC-ACM devices */
    USB_CFG_DEVICE_VERSION, /* 2 bytes */
    1,                      /* manufacturer string index */
    2,                      /* product string index */
    0,                      /* serial number string index */
    1,                      /* number of configurations */
};

static PROGMEM char configDescrCDC[] = {   /* USB configuration descriptor */
    9,          /* sizeof(usbDescrConfig): length of descriptor in bytes */
    USBDESCR_CONFIG,    /* descriptor type */
    67,
    0,          /* total length of data returned (including inlined descriptors) */
    2,          /* number of interfaces in this configuration */
    1,          /* index of this configuration */
    0,          /* configuration name string index */
#if USB_CFG_IS_SELF_POWERED
    USBATTR_SELFPOWER,  /* attributes */
#else
    USBATTR_BUSPOWER,   /* attributes */
#endif
    USB_CFG_MAX_BUS_POWER/2,            /* max USB current in 2mA units */

    /* interface descriptor follows inline: */
    9,          /* sizeof(usbDescrInterface): length of descriptor in bytes */
    USBDESCR_INTERFACE, /* descriptor type */
    0,          /* index of this interface */
    0,          /* alternate setting for this interface */
    USB_CFG_HAVE_INTRIN_ENDPOINT,   /* endpoints excl 0: number of endpoint descriptors to follow */
    USB_CFG_INTERFACE_CLASS,
    USB_CFG_INTERFACE_SUBCLASS,
    USB_CFG_INTERFACE_PROTOCOL,
    0,          /* string index for interface */

    /* CDC Class-Specific descriptor */
    5,           /* sizeof(usbDescrCDC_HeaderFn): length of descriptor in bytes */
    0x24,        /* descriptor type */
    0,           /* header functional descriptor */
    0x10, 0x01,

    4,           /* sizeof(usbDescrCDC_AcmFn): length of descriptor in bytes */
    0x24,        /* descriptor type */
    2,           /* abstract control management functional descriptor */
    0x02,        /* SET_LINE_CODING,    GET_LINE_CODING, SET_CONTROL_LINE_STATE    */

    5,           /* sizeof(usbDescrCDC_UnionFn): length of descriptor in bytes */
    0x24,        /* descriptor type */
    6,           /* union functional descriptor */
    0,           /* CDC_COMM_INTF_ID */
    1,           /* CDC_DATA_INTF_ID */

    5,           /* sizeof(usbDescrCDC_CallMgtFn): length of descriptor in bytes */
    0x24,        /* descriptor type */
    1,           /* call management functional descriptor */
    3,           /* allow management on data interface, handles call management by itself */
    1,           /* CDC_DATA_INTF_ID */

    /* Endpoint Descriptor */
    7,           /* sizeof(usbDescrEndpoint) */
    USBDESCR_ENDPOINT,  /* descriptor type = endpoint */
    0x83,        /* IN endpoint number 3 */
    0x03,        /* attrib: Interrupt endpoint */
    8, 0,        /* maximum packet size */
    2,           /* in ms */

    /* Interface Descriptor  */
    9,           /* sizeof(usbDescrInterface): length of descriptor in bytes */
    USBDESCR_INTERFACE,           /* descriptor type */
    1,           /* index of this interface */
    0,           /* alternate setting for this interface */
    2,           /* endpoints excl 0: number of endpoint descriptors to follow */
    0x0A,        /* Data Interface Class Codes */
    0,
    0,           /* Data Interface Class Protocol Codes */
    0,           /* string index for interface */

    /* Endpoint Descriptor */
    7,           /* sizeof(usbDescrEndpoint) */
    USBDESCR_ENDPOINT,  /* descriptor type = endpoint */
    0x01,        /* OUT endpoint number 1 */
    0x02,        /* attrib: Bulk endpoint */
    HW_CDC_BULK_OUT_SIZE, 0,        /* maximum packet size */
    0,           /* in ms */

    /* Endpoint Descriptor */
    7,           /* sizeof(usbDescrEndpoint) */
    USBDESCR_ENDPOINT,  /* descriptor type = endpoint */
    0x81,        /* IN endpoint number 1 */
    0x02,        /* attrib: Bulk endpoint */
    HW_CDC_BULK_IN_SIZE, 0,        /* maximum packet size */
    0,           /* in ms */
};


uchar usbFunctionDescriptor(usbRequest_t *rq)
{

    if(rq->wValue.bytes[1] == USBDESCR_DEVICE){
        usbMsgPtr = (uchar *)deviceDescrCDC;
        return sizeof(deviceDescrCDC);
    }else{  /* must be config descriptor */
        usbMsgPtr = (uchar *)configDescrCDC;
        return sizeof(configDescrCDC);
    }
}


static uchar        sendEmptyFrame;
static uchar        intr3Status;    /* used to control interrupt endpoint transmissions */

static uchar        stopbit, parity, databit;
static usbDWord_t   baud;

static void resetUart(void)
{

    uartInit(baud.dword, parity, stopbit, databit);
    irptr    = 0;
    iwptr    = 0;
    urptr    = 0;
    uwptr    = 0;
}

/* ------------------------------------------------------------------------- */
/* ----------------------------- USB interface ----------------------------- */
/* ------------------------------------------------------------------------- */

uchar usbFunctionSetup(uchar data[8])
{
usbRequest_t    *rq = (void *)data;

    if((rq->bmRequestType & USBRQ_TYPE_MASK) == USBRQ_TYPE_CLASS){    /* class request type */

        if( rq->bRequest==GET_LINE_CODING || rq->bRequest==SET_LINE_CODING ){
            return 0xff;
        /*    GET_LINE_CODING -> usbFunctionRead()    */
        /*    SET_LINE_CODING -> usbFunctionWrite()    */
        }
        if(rq->bRequest == SET_CONTROL_LINE_STATE){
            /* Report serial state (carrier detect). On several Unix platforms,
             * tty devices can only be opened when carrier detect is set.
             */
            if( intr3Status==0 )
                intr3Status = 2;
        }

        /*  Prepare bulk-in endpoint to respond to early termination   */
        if((rq->bmRequestType & USBRQ_DIR_MASK) == USBRQ_DIR_HOST_TO_DEVICE)
            sendEmptyFrame  = 1;
    }

    return 0;
}


/*---------------------------------------------------------------------------*/
/* usbFunctionRead                                                          */
/*---------------------------------------------------------------------------*/

uchar usbFunctionRead( uchar *data, uchar len )
{

    data[0] = baud.bytes[0];
    data[1] = baud.bytes[1];
    data[2] = baud.bytes[2];
    data[3] = baud.bytes[3];
    data[4] = stopbit;
    data[5] = parity;
    data[6] = databit;

    return 7;
}


/*---------------------------------------------------------------------------*/
/* usbFunctionWrite                                                          */
/*---------------------------------------------------------------------------*/

uchar usbFunctionWrite( uchar *data, uchar len )
{

    /*    SET_LINE_CODING    */
    baud.bytes[0] = data[0];
    baud.bytes[1] = data[1];
    baud.bytes[2] = data[2];
    baud.bytes[3] = data[3];

#if USB_CFG_HAVE_USART
    stopbit    = data[4];
    parity     = data[5];
    databit    = data[6];

    if( parity>2 )
        parity    = 0;
    if( stopbit==1 )
        stopbit    = 0;
#endif
    resetUart();

    return 1;
}


void usbFunctionWriteOut( uchar *data, uchar len )
{

    /*  usb -> rs232c:  transmit char    */
    for( ; len; len-- ) {
        uartTxBufAppend(*data++);
    }

    /*  postpone receiving next data    */
    if( uartTxBytesFree()<=8 )
        usbDisableAllRequests();
}


static void hardwareInit(void)
{
uchar    i, j;

    /* activate pull-ups except on USB lines */
    USB_CFG_IOPORT   = (uchar)~((1<<USB_CFG_DMINUS_BIT)|(1<<USB_CFG_DPLUS_BIT));
    /* all pins input except USB (-> USB reset) */
#ifdef USB_CFG_PULLUP_IOPORT    /* use usbDeviceConnect()/usbDeviceDisconnect() if available */
    USBDDR    = 0;    /* we do RESET by deactivating pullup */
    usbDeviceDisconnect();
#else
    USBDDR    = (1<<USB_CFG_DMINUS_BIT)|(1<<USB_CFG_DPLUS_BIT);
#endif

    j = 0;
    while(--j){          /* USB Reset by device only required on Watchdog Reset */
        i = 0;
        while(--i);      /* delay >10ms for USB reset */
    }
#ifdef USB_CFG_PULLUP_IOPORT
    usbDeviceConnect();
#else
    USBDDR    = 0;      /*  remove USB reset condition */
#endif

    /*    USART configuration    */
    baud.dword  = UART_DEFAULT_BPS;
    stopbit = 0;
    parity  = 0;
    databit = 8;
    resetUart();
}


int main(void)
{

    wdt_enable(WDTO_1S);
    odDebugInit();
    hardwareInit();
    usbInit();

    intr3Status = 0;
    sendEmptyFrame  = 0;

    sei();
    for(;;){    /* main event loop */
        wdt_reset();
        usbPoll();
        uartPoll();

        /*    rs232c -> usb:  transmit char        */
        if( usbInterruptIsReady() ) {
            uchar bytesRead, *data;

            bytesRead = uartRxBytesAvailable(&data);
            if(bytesRead > 0 || sendEmptyFrame){
                if(bytesRead >= HW_CDC_BULK_IN_SIZE) {
                    bytesRead = HW_CDC_BULK_IN_SIZE;
                   /* send an empty block after last data block to indicate transfer end */
                    sendEmptyFrame  = 1;
                }
                else
                    sendEmptyFrame  = 0;
                usbSetInterrupt(data, bytesRead);
                uartRxDidReadBytes(bytesRead);
            }
        }

        /* We need to report rx and tx carrier after open attempt */
        if(intr3Status != 0 && usbInterruptIsReady3()){
            static uchar serialStateNotification[10] = {0xa1, 0x20, 0, 0, 0, 0, 2, 0, 3, 0};

            if(intr3Status == 2){
                usbSetInterrupt3(serialStateNotification, 8);
            }else{
                usbSetInterrupt3(serialStateNotification+8, 2);
            }
            intr3Status--;
        }
    }
    return 0;
}