usblib.c

VxWorks下USB驱动的源代码！

/* usbLib.c - USB utility functions */

/* Copyright 2000-2002 Wind River Systems, Inc. */

/*
Modification history
--------------------
01l,09nov01,wef  Test for NULL on OSS_xALLOC calls, change sizeof () to 
		 structure size macros
01k,25oct01,wef  repalce automatic buffer creations with calls to OSS_MALLOC
                 in places where the buffer is passed to the hardware (related
                 to SPR 70492).
01j,18sep01,wef  merge from wrs.tor2_0.usb1_1-f for veloce
01e,25jul01,jgn  fixed spr 69287
01d,26jan00,rcb  Modify usbRecurringTime() to accept <bandwidth> instead
		 of <bytesPerFrame>.
		 Add usbDescrCopy32() and usbDescrStrCopy32().
01c,17jan00,rcb  Add usbConfigDescrGet() function.
01b,23nov99,rcb  Add usbRecurringTime() function.
01a,16jul99,rcb  First.
*/

/*
DESCRIPTION

This modules contains miscellaneous functions which may be used by the
USB driver (USBD), USB HCD (USB Host Controller Driver), or by USBD clients.
*/


/* includes */

#include "usb/usbPlatform.h"

#include "string.h"

#include "usb/usbdLib.h"
#include "usb/usbLib.h"


/* defines */

/* USB time constants.
 *
 * NOTE: The following constants use units of picoseconds for improved
 * calculation resolution.  The calcTdTime() function - below - rounds
 * the final calculated to the next higher nanosecond, and returns the
 * calculated value in terms of nanoseconds.
 */

#define TIME_OVRHD_INPUT_NON_ISOCH  ((UINT32) 9107000L)
#define TIME_OVRHD_INPUT_ISOCH	    ((UINT32) 7268000L)
#define TIME_OVRHD_OUTPUT_NON_ISOCH ((UINT32) 9107000L)
#define TIME_OVRHD_OUTPUT_ISOCH     ((UINT32) 6265000L)

#define TIME_OVRHD_INPUT_LS	    ((UINT32) 64060000L)
#define TIME_OVRHD_OUTPUT_LS	    ((UINT32) 64107000L)

#define TIME_BIT		    ((UINT32) 83540L)
#define TIME_BIT_LS_INPUT	    ((UINT32) 676670L)
#define TIME_BIT_LS_OUTPUT	    ((UINT32) 667000L)


/* BIT_STUFF calculates the worst case number of bits for the indicated
 * number of bytes.  (The "19" in the following equation is equal to
 * 3.167*6.  Since 19 is added to the bit total which is then divided by
 * 6, this has the effect of ading 3.167 bit times to the total.
 */

#define BIT_STUFF(bytes)    ((UINT32) ((((UINT32) bytes) * 8 * 7 + 19) / 6))


/* functions */

/***************************************************************************
*
* usbTransferTime - Calculates bus time required for a USB transfer
*
* This function calculates the amount of time a transfer of a given number
* of bytes will require on the bus - measured in nanoseconds (10E-9 seconds).  
* The formulas used here are taken from Section 5.9.3 of Revision 1.1 of the 
* USB spec.
*
* <transferType>, <direction>, and <speed> should describe the characteristics
* of the pipe/transfer as USB_XFRTYPE_xxxx, USB_DIR_xxxx, and USB_SPEED_xxxx,
* repsectively.  <bytes> is the size of the packet for which the transfer time 
* should be calculated. <hostDelay> and <hostHubLsSetup> are the host delay and 
* low-speed hub setup times in nanoseconds, respectively, and are host-controller 
* specific.
*
* RETURNS: Worst case number of nanoseconds required for transfer
*/

UINT32 usbTransferTime (UINT16 transferType,    /* transfer type */
                        UINT16 direction,   /* transfer direction */
                        UINT16 speed,   /* speed of pipe */
                        UINT32 bytes,   /* number of bytes for packet to be calc'd */
                        UINT32 hostDelay,   /* host controller delay per packet */
                        UINT32 hostHubLsSetup   /* host controller time for low-speed setup */
    )
{
    UINT32 bits = BIT_STUFF (bytes);
    UINT32 ps;

    if (speed == USB_SPEED_FULL) {
        if (direction == USB_DIR_IN) {
            if (transferType == USB_XFRTYPE_ISOCH) {
                ps = TIME_OVRHD_INPUT_ISOCH + TIME_BIT * bits;
            } else {
                ps = TIME_OVRHD_INPUT_NON_ISOCH + TIME_BIT * bits;
            }
        } else {
            if (transferType == USB_XFRTYPE_ISOCH) {
                ps = TIME_OVRHD_OUTPUT_ISOCH + TIME_BIT * bits;
            } else {
                ps = TIME_OVRHD_OUTPUT_NON_ISOCH + TIME_BIT * bits;
            }
        }
    } else {
        if (direction == USB_DIR_IN) {
            ps = TIME_OVRHD_INPUT_LS + 2 * hostHubLsSetup * 1000L + TIME_BIT_LS_INPUT * bits;
        } else {
            ps = TIME_OVRHD_OUTPUT_LS + 2 * hostHubLsSetup * 1000L + TIME_BIT_LS_OUTPUT * bits;
        }
    }

    ps += hostDelay * 1000L;

    return (ps + 999L) / 1000L; /* returns value in nanoseconds */
}


/***************************************************************************
*
* usbRecurringTime - calculates recurring time for interrupt/isoch transfers
*
* For recurring transfers (e.g., interrupt or isochronous transfers) an HCD
* needs to be able to calculate the amount of bus time - measured in 
* nanoseconds - which will be used by the transfer.
*
* <transferType> specifies the type of transfer.  For USB_XFRTYPE_CONTROL and
* USB_XFRTYPE_BULK, the calculated time is always 0...these are not recurring
* transfers.  For USB_XFRTYPE_INTERRUPT, <bandwidth> must express the number
* of bytes to be transferred in each frame.  For USB_XFRTYPE_ISOCH, <bandwidth>
* must express the number of bytes to be transferred in each second.  The
* parameter is treated differently to allow greater flexibility in determining
* the true bandwidth requirements for each type of pipe.
*
* RETURNS: worst case number of nanoseconds required for transfer.
*/

UINT32 usbRecurringTime (UINT16 transferType,   /* transfer type */
                         UINT16 direction,  /* transfer direction */
                         UINT16 speed,  /* speed of pipe */
                         UINT16 packetSize, /* max packet size for endpoint */
                         UINT32 bandwidth,  /* bytes/frame or bytes/sec depending on pipe */
                         UINT32 hostDelay,  /* host controller delay per packet */
                         UINT32 hostHubLsSetup  /* host controller time for low-speed setup */
    )
{
    UINT16 packets;
    UINT32 nanosecondsPerPacket;
    UINT16 remainderBytes;
    UINT32 remainderNanoseconds;
    UINT32 bytesPerFrame;


    /* Non-recurring transfers always return 0. */

    if (transferType == USB_XFRTYPE_CONTROL || transferType == USB_XFRTYPE_BULK)
        return 0;


    /* Calculate time for recurring transfer */

    if (transferType == USB_XFRTYPE_INTERRUPT)
        bytesPerFrame = bandwidth;
    else                        /* transferType == USB_XFRTYPE_ISOCH */
        bytesPerFrame = (bandwidth + 999L) / 1000L;

    packets = bytesPerFrame / packetSize;
    remainderBytes = bytesPerFrame % packetSize;

    nanosecondsPerPacket = usbTransferTime (transferType, direction,
                                            speed, packetSize, hostDelay, hostHubLsSetup);

    if (remainderBytes > 0)
        remainderNanoseconds = usbTransferTime (transferType, direction,
                                                speed, remainderBytes, hostDelay, hostHubLsSetup);
    else
        remainderNanoseconds = 0;

    return packets * nanosecondsPerPacket + remainderNanoseconds;
}


/***************************************************************************
*
* usbDescrParseSkip - search for a descriptor and increment buffer
*
* Searches <ppBfr> up to <pBfrLen> bytes for a descriptor of type matching
* <descriptorType>.  Returns a pointer to the descriptor if found.  <ppBfr> 
* and <pBfrLen> are updated to reflect the next location in the buffer and 
* the remaining size of the buffer, respectively.
*
* RETURNS: pointer to indicated descriptor, or NULL if descr not found.
*/

pVOID usbDescrParseSkip (pUINT8 * ppBfr,    /* buffer to parse */
                         pUINT16 pBfrLen,   /* length of buffer to parse */
                         UINT8 descriptorType   /* type of descriptor being sought */
    )
{
    pUSB_DESCR_HDR pHdr;

    /* The remaining buffer length must be at least two bytes to accommodate
     * the descriptor length and descriptorType fields.  If not, we're done. 
     */

    while (*pBfrLen >= sizeof (pHdr->length) + sizeof (pHdr->descriptorType)) {
        pHdr = (pUSB_DESCR_HDR) * ppBfr;

        if (pHdr->length == 0)
            return NULL;        /* must be invalid */

        *ppBfr += min (pHdr->length, *pBfrLen);
        *pBfrLen -= min (pHdr->length, *pBfrLen);

        if (pHdr->descriptorType == descriptorType)
            return (pVOID) pHdr;
    }

    return NULL;
}


/***************************************************************************
*