USBasp/firmware/usbdrv/usbdrv.c
Stefan Beller da7b6e47c7 Initial commit.
This includes the files as of
wget http://www.fischl.de/usbasp/usbasp.2011-05-28.tar.gz
tar -xf usbasp.2011.05-28.tar.gz
2012-05-19 16:27:27 +02:00

626 lines
24 KiB
C

/* Name: usbdrv.c
* Project: V-USB, virtual USB port for Atmel's(r) AVR(r) microcontrollers
* Author: Christian Starkjohann
* Creation Date: 2004-12-29
* Tabsize: 4
* Copyright: (c) 2005 by OBJECTIVE DEVELOPMENT Software GmbH
* License: GNU GPL v2 (see License.txt), GNU GPL v3 or proprietary (CommercialLicense.txt)
* This Revision: $Id: usbdrv.c 791 2010-07-15 15:56:13Z cs $
*/
#include "usbportability.h"
#include "usbdrv.h"
#include "oddebug.h"
/*
General Description:
This module implements the C-part of the USB driver. See usbdrv.h for a
documentation of the entire driver.
*/
/* ------------------------------------------------------------------------- */
/* raw USB registers / interface to assembler code: */
uchar usbRxBuf[2*USB_BUFSIZE]; /* raw RX buffer: PID, 8 bytes data, 2 bytes CRC */
uchar usbInputBufOffset; /* offset in usbRxBuf used for low level receiving */
uchar usbDeviceAddr; /* assigned during enumeration, defaults to 0 */
uchar usbNewDeviceAddr; /* device ID which should be set after status phase */
uchar usbConfiguration; /* currently selected configuration. Administered by driver, but not used */
volatile schar usbRxLen; /* = 0; number of bytes in usbRxBuf; 0 means free, -1 for flow control */
uchar usbCurrentTok; /* last token received or endpoint number for last OUT token if != 0 */
uchar usbRxToken; /* token for data we received; or endpont number for last OUT */
volatile uchar usbTxLen = USBPID_NAK; /* number of bytes to transmit with next IN token or handshake token */
uchar usbTxBuf[USB_BUFSIZE];/* data to transmit with next IN, free if usbTxLen contains handshake token */
#if USB_COUNT_SOF
volatile uchar usbSofCount; /* incremented by assembler module every SOF */
#endif
#if USB_CFG_HAVE_INTRIN_ENDPOINT && !USB_CFG_SUPPRESS_INTR_CODE
usbTxStatus_t usbTxStatus1;
# if USB_CFG_HAVE_INTRIN_ENDPOINT3
usbTxStatus_t usbTxStatus3;
# endif
#endif
#if USB_CFG_CHECK_DATA_TOGGLING
uchar usbCurrentDataToken;/* when we check data toggling to ignore duplicate packets */
#endif
/* USB status registers / not shared with asm code */
uchar *usbMsgPtr; /* data to transmit next -- ROM or RAM address */
static usbMsgLen_t usbMsgLen = USB_NO_MSG; /* remaining number of bytes */
static uchar usbMsgFlags; /* flag values see below */
#define USB_FLG_MSGPTR_IS_ROM (1<<6)
#define USB_FLG_USE_USER_RW (1<<7)
/*
optimizing hints:
- do not post/pre inc/dec integer values in operations
- assign value of USB_READ_FLASH() to register variables and don't use side effects in arg
- use narrow scope for variables which should be in X/Y/Z register
- assign char sized expressions to variables to force 8 bit arithmetics
*/
/* -------------------------- String Descriptors --------------------------- */
#if USB_CFG_DESCR_PROPS_STRINGS == 0
#if USB_CFG_DESCR_PROPS_STRING_0 == 0
#undef USB_CFG_DESCR_PROPS_STRING_0
#define USB_CFG_DESCR_PROPS_STRING_0 sizeof(usbDescriptorString0)
PROGMEM char usbDescriptorString0[] = { /* language descriptor */
4, /* sizeof(usbDescriptorString0): length of descriptor in bytes */
3, /* descriptor type */
0x09, 0x04, /* language index (0x0409 = US-English) */
};
#endif
#if USB_CFG_DESCR_PROPS_STRING_VENDOR == 0 && USB_CFG_VENDOR_NAME_LEN
#undef USB_CFG_DESCR_PROPS_STRING_VENDOR
#define USB_CFG_DESCR_PROPS_STRING_VENDOR sizeof(usbDescriptorStringVendor)
PROGMEM int usbDescriptorStringVendor[] = {
USB_STRING_DESCRIPTOR_HEADER(USB_CFG_VENDOR_NAME_LEN),
USB_CFG_VENDOR_NAME
};
#endif
#if USB_CFG_DESCR_PROPS_STRING_PRODUCT == 0 && USB_CFG_DEVICE_NAME_LEN
#undef USB_CFG_DESCR_PROPS_STRING_PRODUCT
#define USB_CFG_DESCR_PROPS_STRING_PRODUCT sizeof(usbDescriptorStringDevice)
PROGMEM int usbDescriptorStringDevice[] = {
USB_STRING_DESCRIPTOR_HEADER(USB_CFG_DEVICE_NAME_LEN),
USB_CFG_DEVICE_NAME
};
#endif
#if USB_CFG_DESCR_PROPS_STRING_SERIAL_NUMBER == 0 && USB_CFG_SERIAL_NUMBER_LEN
#undef USB_CFG_DESCR_PROPS_STRING_SERIAL_NUMBER
#define USB_CFG_DESCR_PROPS_STRING_SERIAL_NUMBER sizeof(usbDescriptorStringSerialNumber)
PROGMEM int usbDescriptorStringSerialNumber[] = {
USB_STRING_DESCRIPTOR_HEADER(USB_CFG_SERIAL_NUMBER_LEN),
USB_CFG_SERIAL_NUMBER
};
#endif
#endif /* USB_CFG_DESCR_PROPS_STRINGS == 0 */
/* --------------------------- Device Descriptor --------------------------- */
#if USB_CFG_DESCR_PROPS_DEVICE == 0
#undef USB_CFG_DESCR_PROPS_DEVICE
#define USB_CFG_DESCR_PROPS_DEVICE sizeof(usbDescriptorDevice)
PROGMEM char usbDescriptorDevice[] = { /* USB device descriptor */
18, /* sizeof(usbDescriptorDevice): length of descriptor in bytes */
USBDESCR_DEVICE, /* descriptor type */
0x10, 0x01, /* USB version supported */
USB_CFG_DEVICE_CLASS,
USB_CFG_DEVICE_SUBCLASS,
0, /* protocol */
8, /* max packet size */
/* the following two casts affect the first byte of the constant only, but
* that's sufficient to avoid a warning with the default values.
*/
(char)USB_CFG_VENDOR_ID,/* 2 bytes */
(char)USB_CFG_DEVICE_ID,/* 2 bytes */
USB_CFG_DEVICE_VERSION, /* 2 bytes */
USB_CFG_DESCR_PROPS_STRING_VENDOR != 0 ? 1 : 0, /* manufacturer string index */
USB_CFG_DESCR_PROPS_STRING_PRODUCT != 0 ? 2 : 0, /* product string index */
USB_CFG_DESCR_PROPS_STRING_SERIAL_NUMBER != 0 ? 3 : 0, /* serial number string index */
1, /* number of configurations */
};
#endif
/* ----------------------- Configuration Descriptor ------------------------ */
#if USB_CFG_DESCR_PROPS_HID_REPORT != 0 && USB_CFG_DESCR_PROPS_HID == 0
#undef USB_CFG_DESCR_PROPS_HID
#define USB_CFG_DESCR_PROPS_HID 9 /* length of HID descriptor in config descriptor below */
#endif
#if USB_CFG_DESCR_PROPS_CONFIGURATION == 0
#undef USB_CFG_DESCR_PROPS_CONFIGURATION
#define USB_CFG_DESCR_PROPS_CONFIGURATION sizeof(usbDescriptorConfiguration)
PROGMEM char usbDescriptorConfiguration[] = { /* USB configuration descriptor */
9, /* sizeof(usbDescriptorConfiguration): length of descriptor in bytes */
USBDESCR_CONFIG, /* descriptor type */
18 + 7 * USB_CFG_HAVE_INTRIN_ENDPOINT + 7 * USB_CFG_HAVE_INTRIN_ENDPOINT3 +
(USB_CFG_DESCR_PROPS_HID & 0xff), 0,
/* total length of data returned (including inlined descriptors) */
1, /* number of interfaces in this configuration */
1, /* index of this configuration */
0, /* configuration name string index */
#if USB_CFG_IS_SELF_POWERED
(1 << 7) | USBATTR_SELFPOWER, /* attributes */
#else
(1 << 7), /* 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 + USB_CFG_HAVE_INTRIN_ENDPOINT3, /* 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 */
#if (USB_CFG_DESCR_PROPS_HID & 0xff) /* HID descriptor */
9, /* sizeof(usbDescrHID): length of descriptor in bytes */
USBDESCR_HID, /* descriptor type: HID */
0x01, 0x01, /* BCD representation of HID version */
0x00, /* target country code */
0x01, /* number of HID Report (or other HID class) Descriptor infos to follow */
0x22, /* descriptor type: report */
USB_CFG_HID_REPORT_DESCRIPTOR_LENGTH, 0, /* total length of report descriptor */
#endif
#if USB_CFG_HAVE_INTRIN_ENDPOINT /* endpoint descriptor for endpoint 1 */
7, /* sizeof(usbDescrEndpoint) */
USBDESCR_ENDPOINT, /* descriptor type = endpoint */
(char)0x81, /* IN endpoint number 1 */
0x03, /* attrib: Interrupt endpoint */
8, 0, /* maximum packet size */
USB_CFG_INTR_POLL_INTERVAL, /* in ms */
#endif
#if USB_CFG_HAVE_INTRIN_ENDPOINT3 /* endpoint descriptor for endpoint 3 */
7, /* sizeof(usbDescrEndpoint) */
USBDESCR_ENDPOINT, /* descriptor type = endpoint */
(char)(0x80 | USB_CFG_EP3_NUMBER), /* IN endpoint number 3 */
0x03, /* attrib: Interrupt endpoint */
8, 0, /* maximum packet size */
USB_CFG_INTR_POLL_INTERVAL, /* in ms */
#endif
};
#endif
/* ------------------------------------------------------------------------- */
static inline void usbResetDataToggling(void)
{
#if USB_CFG_HAVE_INTRIN_ENDPOINT && !USB_CFG_SUPPRESS_INTR_CODE
USB_SET_DATATOKEN1(USB_INITIAL_DATATOKEN); /* reset data toggling for interrupt endpoint */
# if USB_CFG_HAVE_INTRIN_ENDPOINT3
USB_SET_DATATOKEN3(USB_INITIAL_DATATOKEN); /* reset data toggling for interrupt endpoint */
# endif
#endif
}
static inline void usbResetStall(void)
{
#if USB_CFG_IMPLEMENT_HALT && USB_CFG_HAVE_INTRIN_ENDPOINT
usbTxLen1 = USBPID_NAK;
#if USB_CFG_HAVE_INTRIN_ENDPOINT3
usbTxLen3 = USBPID_NAK;
#endif
#endif
}
/* ------------------------------------------------------------------------- */
#if !USB_CFG_SUPPRESS_INTR_CODE
#if USB_CFG_HAVE_INTRIN_ENDPOINT
static void usbGenericSetInterrupt(uchar *data, uchar len, usbTxStatus_t *txStatus)
{
uchar *p;
char i;
#if USB_CFG_IMPLEMENT_HALT
if(usbTxLen1 == USBPID_STALL)
return;
#endif
if(txStatus->len & 0x10){ /* packet buffer was empty */
txStatus->buffer[0] ^= USBPID_DATA0 ^ USBPID_DATA1; /* toggle token */
}else{
txStatus->len = USBPID_NAK; /* avoid sending outdated (overwritten) interrupt data */
}
p = txStatus->buffer + 1;
i = len;
do{ /* if len == 0, we still copy 1 byte, but that's no problem */
*p++ = *data++;
}while(--i > 0); /* loop control at the end is 2 bytes shorter than at beginning */
usbCrc16Append(&txStatus->buffer[1], len);
txStatus->len = len + 4; /* len must be given including sync byte */
DBG2(0x21 + (((int)txStatus >> 3) & 3), txStatus->buffer, len + 3);
}
USB_PUBLIC void usbSetInterrupt(uchar *data, uchar len)
{
usbGenericSetInterrupt(data, len, &usbTxStatus1);
}
#endif
#if USB_CFG_HAVE_INTRIN_ENDPOINT3
USB_PUBLIC void usbSetInterrupt3(uchar *data, uchar len)
{
usbGenericSetInterrupt(data, len, &usbTxStatus3);
}
#endif
#endif /* USB_CFG_SUPPRESS_INTR_CODE */
/* ------------------ utilities for code following below ------------------- */
/* Use defines for the switch statement so that we can choose between an
* if()else if() and a switch/case based implementation. switch() is more
* efficient for a LARGE set of sequential choices, if() is better in all other
* cases.
*/
#if USB_CFG_USE_SWITCH_STATEMENT
# define SWITCH_START(cmd) switch(cmd){{
# define SWITCH_CASE(value) }break; case (value):{
# define SWITCH_CASE2(v1,v2) }break; case (v1): case(v2):{
# define SWITCH_CASE3(v1,v2,v3) }break; case (v1): case(v2): case(v3):{
# define SWITCH_DEFAULT }break; default:{
# define SWITCH_END }}
#else
# define SWITCH_START(cmd) {uchar _cmd = cmd; if(0){
# define SWITCH_CASE(value) }else if(_cmd == (value)){
# define SWITCH_CASE2(v1,v2) }else if(_cmd == (v1) || _cmd == (v2)){
# define SWITCH_CASE3(v1,v2,v3) }else if(_cmd == (v1) || _cmd == (v2) || (_cmd == v3)){
# define SWITCH_DEFAULT }else{
# define SWITCH_END }}
#endif
#ifndef USB_RX_USER_HOOK
#define USB_RX_USER_HOOK(data, len)
#endif
#ifndef USB_SET_ADDRESS_HOOK
#define USB_SET_ADDRESS_HOOK()
#endif
/* ------------------------------------------------------------------------- */
/* We use if() instead of #if in the macro below because #if can't be used
* in macros and the compiler optimizes constant conditions anyway.
* This may cause problems with undefined symbols if compiled without
* optimizing!
*/
#define GET_DESCRIPTOR(cfgProp, staticName) \
if(cfgProp){ \
if((cfgProp) & USB_PROP_IS_RAM) \
flags = 0; \
if((cfgProp) & USB_PROP_IS_DYNAMIC){ \
len = usbFunctionDescriptor(rq); \
}else{ \
len = USB_PROP_LENGTH(cfgProp); \
usbMsgPtr = (uchar *)(staticName); \
} \
}
/* usbDriverDescriptor() is similar to usbFunctionDescriptor(), but used
* internally for all types of descriptors.
*/
static inline usbMsgLen_t usbDriverDescriptor(usbRequest_t *rq)
{
usbMsgLen_t len = 0;
uchar flags = USB_FLG_MSGPTR_IS_ROM;
SWITCH_START(rq->wValue.bytes[1])
SWITCH_CASE(USBDESCR_DEVICE) /* 1 */
GET_DESCRIPTOR(USB_CFG_DESCR_PROPS_DEVICE, usbDescriptorDevice)
SWITCH_CASE(USBDESCR_CONFIG) /* 2 */
GET_DESCRIPTOR(USB_CFG_DESCR_PROPS_CONFIGURATION, usbDescriptorConfiguration)
SWITCH_CASE(USBDESCR_STRING) /* 3 */
#if USB_CFG_DESCR_PROPS_STRINGS & USB_PROP_IS_DYNAMIC
if(USB_CFG_DESCR_PROPS_STRINGS & USB_PROP_IS_RAM)
flags = 0;
len = usbFunctionDescriptor(rq);
#else /* USB_CFG_DESCR_PROPS_STRINGS & USB_PROP_IS_DYNAMIC */
SWITCH_START(rq->wValue.bytes[0])
SWITCH_CASE(0)
GET_DESCRIPTOR(USB_CFG_DESCR_PROPS_STRING_0, usbDescriptorString0)
SWITCH_CASE(1)
GET_DESCRIPTOR(USB_CFG_DESCR_PROPS_STRING_VENDOR, usbDescriptorStringVendor)
SWITCH_CASE(2)
GET_DESCRIPTOR(USB_CFG_DESCR_PROPS_STRING_PRODUCT, usbDescriptorStringDevice)
SWITCH_CASE(3)
GET_DESCRIPTOR(USB_CFG_DESCR_PROPS_STRING_SERIAL_NUMBER, usbDescriptorStringSerialNumber)
SWITCH_DEFAULT
if(USB_CFG_DESCR_PROPS_UNKNOWN & USB_PROP_IS_DYNAMIC){
len = usbFunctionDescriptor(rq);
}
SWITCH_END
#endif /* USB_CFG_DESCR_PROPS_STRINGS & USB_PROP_IS_DYNAMIC */
#if USB_CFG_DESCR_PROPS_HID_REPORT /* only support HID descriptors if enabled */
SWITCH_CASE(USBDESCR_HID) /* 0x21 */
GET_DESCRIPTOR(USB_CFG_DESCR_PROPS_HID, usbDescriptorConfiguration + 18)
SWITCH_CASE(USBDESCR_HID_REPORT)/* 0x22 */
GET_DESCRIPTOR(USB_CFG_DESCR_PROPS_HID_REPORT, usbDescriptorHidReport)
#endif
SWITCH_DEFAULT
if(USB_CFG_DESCR_PROPS_UNKNOWN & USB_PROP_IS_DYNAMIC){
len = usbFunctionDescriptor(rq);
}
SWITCH_END
usbMsgFlags = flags;
return len;
}
/* ------------------------------------------------------------------------- */
/* usbDriverSetup() is similar to usbFunctionSetup(), but it's used for
* standard requests instead of class and custom requests.
*/
static inline usbMsgLen_t usbDriverSetup(usbRequest_t *rq)
{
uchar len = 0, *dataPtr = usbTxBuf + 9; /* there are 2 bytes free space at the end of the buffer */
uchar value = rq->wValue.bytes[0];
#if USB_CFG_IMPLEMENT_HALT
uchar index = rq->wIndex.bytes[0];
#endif
dataPtr[0] = 0; /* default reply common to USBRQ_GET_STATUS and USBRQ_GET_INTERFACE */
SWITCH_START(rq->bRequest)
SWITCH_CASE(USBRQ_GET_STATUS) /* 0 */
uchar recipient = rq->bmRequestType & USBRQ_RCPT_MASK; /* assign arith ops to variables to enforce byte size */
if(USB_CFG_IS_SELF_POWERED && recipient == USBRQ_RCPT_DEVICE)
dataPtr[0] = USB_CFG_IS_SELF_POWERED;
#if USB_CFG_IMPLEMENT_HALT
if(recipient == USBRQ_RCPT_ENDPOINT && index == 0x81) /* request status for endpoint 1 */
dataPtr[0] = usbTxLen1 == USBPID_STALL;
#endif
dataPtr[1] = 0;
len = 2;
#if USB_CFG_IMPLEMENT_HALT
SWITCH_CASE2(USBRQ_CLEAR_FEATURE, USBRQ_SET_FEATURE) /* 1, 3 */
if(value == 0 && index == 0x81){ /* feature 0 == HALT for endpoint == 1 */
usbTxLen1 = rq->bRequest == USBRQ_CLEAR_FEATURE ? USBPID_NAK : USBPID_STALL;
usbResetDataToggling();
}
#endif
SWITCH_CASE(USBRQ_SET_ADDRESS) /* 5 */
usbNewDeviceAddr = value;
USB_SET_ADDRESS_HOOK();
SWITCH_CASE(USBRQ_GET_DESCRIPTOR) /* 6 */
len = usbDriverDescriptor(rq);
goto skipMsgPtrAssignment;
SWITCH_CASE(USBRQ_GET_CONFIGURATION) /* 8 */
dataPtr = &usbConfiguration; /* send current configuration value */
len = 1;
SWITCH_CASE(USBRQ_SET_CONFIGURATION) /* 9 */
usbConfiguration = value;
usbResetStall();
SWITCH_CASE(USBRQ_GET_INTERFACE) /* 10 */
len = 1;
#if USB_CFG_HAVE_INTRIN_ENDPOINT && !USB_CFG_SUPPRESS_INTR_CODE
SWITCH_CASE(USBRQ_SET_INTERFACE) /* 11 */
usbResetDataToggling();
usbResetStall();
#endif
SWITCH_DEFAULT /* 7=SET_DESCRIPTOR, 12=SYNC_FRAME */
/* Should we add an optional hook here? */
SWITCH_END
usbMsgPtr = dataPtr;
skipMsgPtrAssignment:
return len;
}
/* ------------------------------------------------------------------------- */
/* usbProcessRx() is called for every message received by the interrupt
* routine. It distinguishes between SETUP and DATA packets and processes
* them accordingly.
*/
static inline void usbProcessRx(uchar *data, uchar len)
{
usbRequest_t *rq = (void *)data;
/* usbRxToken can be:
* 0x2d 00101101 (USBPID_SETUP for setup data)
* 0xe1 11100001 (USBPID_OUT: data phase of setup transfer)
* 0...0x0f for OUT on endpoint X
*/
DBG2(0x10 + (usbRxToken & 0xf), data, len + 2); /* SETUP=1d, SETUP-DATA=11, OUTx=1x */
USB_RX_USER_HOOK(data, len)
#if USB_CFG_IMPLEMENT_FN_WRITEOUT
if(usbRxToken < 0x10){ /* OUT to endpoint != 0: endpoint number in usbRxToken */
usbFunctionWriteOut(data, len);
return;
}
#endif
if(usbRxToken == (uchar)USBPID_SETUP){
if(len != 8) /* Setup size must be always 8 bytes. Ignore otherwise. */
return;
usbMsgLen_t replyLen;
usbTxBuf[0] = USBPID_DATA0; /* initialize data toggling */
usbTxLen = USBPID_NAK; /* abort pending transmit */
usbMsgFlags = 0;
uchar type = rq->bmRequestType & USBRQ_TYPE_MASK;
if(type != USBRQ_TYPE_STANDARD){ /* standard requests are handled by driver */
replyLen = usbFunctionSetup(data);
}else{
replyLen = usbDriverSetup(rq);
}
#if USB_CFG_IMPLEMENT_FN_READ || USB_CFG_IMPLEMENT_FN_WRITE
if(replyLen == USB_NO_MSG){ /* use user-supplied read/write function */
/* do some conditioning on replyLen, but on IN transfers only */
if((rq->bmRequestType & USBRQ_DIR_MASK) != USBRQ_DIR_HOST_TO_DEVICE){
if(sizeof(replyLen) < sizeof(rq->wLength.word)){ /* help compiler with optimizing */
replyLen = rq->wLength.bytes[0];
}else{
replyLen = rq->wLength.word;
}
}
usbMsgFlags = USB_FLG_USE_USER_RW;
}else /* The 'else' prevents that we limit a replyLen of USB_NO_MSG to the maximum transfer len. */
#endif
if(sizeof(replyLen) < sizeof(rq->wLength.word)){ /* help compiler with optimizing */
if(!rq->wLength.bytes[1] && replyLen > rq->wLength.bytes[0]) /* limit length to max */
replyLen = rq->wLength.bytes[0];
}else{
if(replyLen > rq->wLength.word) /* limit length to max */
replyLen = rq->wLength.word;
}
usbMsgLen = replyLen;
}else{ /* usbRxToken must be USBPID_OUT, which means data phase of setup (control-out) */
#if USB_CFG_IMPLEMENT_FN_WRITE
if(usbMsgFlags & USB_FLG_USE_USER_RW){
uchar rval = usbFunctionWrite(data, len);
if(rval == 0xff){ /* an error occurred */
usbTxLen = USBPID_STALL;
}else if(rval != 0){ /* This was the final package */
usbMsgLen = 0; /* answer with a zero-sized data packet */
}
}
#endif
}
}
/* ------------------------------------------------------------------------- */
/* This function is similar to usbFunctionRead(), but it's also called for
* data handled automatically by the driver (e.g. descriptor reads).
*/
static uchar usbDeviceRead(uchar *data, uchar len)
{
if(len > 0){ /* don't bother app with 0 sized reads */
#if USB_CFG_IMPLEMENT_FN_READ
if(usbMsgFlags & USB_FLG_USE_USER_RW){
len = usbFunctionRead(data, len);
}else
#endif
{
uchar i = len, *r = usbMsgPtr;
if(usbMsgFlags & USB_FLG_MSGPTR_IS_ROM){ /* ROM data */
do{
uchar c = USB_READ_FLASH(r); /* assign to char size variable to enforce byte ops */
*data++ = c;
r++;
}while(--i);
}else{ /* RAM data */
do{
*data++ = *r++;
}while(--i);
}
usbMsgPtr = r;
}
}
return len;
}
/* ------------------------------------------------------------------------- */
/* usbBuildTxBlock() is called when we have data to transmit and the
* interrupt routine's transmit buffer is empty.
*/
static inline void usbBuildTxBlock(void)
{
usbMsgLen_t wantLen;
uchar len;
wantLen = usbMsgLen;
if(wantLen > 8)
wantLen = 8;
usbMsgLen -= wantLen;
usbTxBuf[0] ^= USBPID_DATA0 ^ USBPID_DATA1; /* DATA toggling */
len = usbDeviceRead(usbTxBuf + 1, wantLen);
if(len <= 8){ /* valid data packet */
usbCrc16Append(&usbTxBuf[1], len);
len += 4; /* length including sync byte */
if(len < 12) /* a partial package identifies end of message */
usbMsgLen = USB_NO_MSG;
}else{
len = USBPID_STALL; /* stall the endpoint */
usbMsgLen = USB_NO_MSG;
}
usbTxLen = len;
DBG2(0x20, usbTxBuf, len-1);
}
/* ------------------------------------------------------------------------- */
static inline void usbHandleResetHook(uchar notResetState)
{
#ifdef USB_RESET_HOOK
static uchar wasReset;
uchar isReset = !notResetState;
if(wasReset != isReset){
USB_RESET_HOOK(isReset);
wasReset = isReset;
}
#endif
}
/* ------------------------------------------------------------------------- */
USB_PUBLIC void usbPoll(void)
{
schar len;
uchar i;
len = usbRxLen - 3;
if(len >= 0){
/* We could check CRC16 here -- but ACK has already been sent anyway. If you
* need data integrity checks with this driver, check the CRC in your app
* code and report errors back to the host. Since the ACK was already sent,
* retries must be handled on application level.
* unsigned crc = usbCrc16(buffer + 1, usbRxLen - 3);
*/
usbProcessRx(usbRxBuf + USB_BUFSIZE + 1 - usbInputBufOffset, len);
#if USB_CFG_HAVE_FLOWCONTROL
if(usbRxLen > 0) /* only mark as available if not inactivated */
usbRxLen = 0;
#else
usbRxLen = 0; /* mark rx buffer as available */
#endif
}
if(usbTxLen & 0x10){ /* transmit system idle */
if(usbMsgLen != USB_NO_MSG){ /* transmit data pending? */
usbBuildTxBlock();
}
}
for(i = 20; i > 0; i--){
uchar usbLineStatus = USBIN & USBMASK;
if(usbLineStatus != 0) /* SE0 has ended */
goto isNotReset;
}
/* RESET condition, called multiple times during reset */
usbNewDeviceAddr = 0;
usbDeviceAddr = 0;
usbResetStall();
DBG1(0xff, 0, 0);
isNotReset:
usbHandleResetHook(i);
}
/* ------------------------------------------------------------------------- */
USB_PUBLIC void usbInit(void)
{
#if USB_INTR_CFG_SET != 0
USB_INTR_CFG |= USB_INTR_CFG_SET;
#endif
#if USB_INTR_CFG_CLR != 0
USB_INTR_CFG &= ~(USB_INTR_CFG_CLR);
#endif
USB_INTR_ENABLE |= (1 << USB_INTR_ENABLE_BIT);
usbResetDataToggling();
#if USB_CFG_HAVE_INTRIN_ENDPOINT && !USB_CFG_SUPPRESS_INTR_CODE
usbTxLen1 = USBPID_NAK;
#if USB_CFG_HAVE_INTRIN_ENDPOINT3
usbTxLen3 = USBPID_NAK;
#endif
#endif
}
/* ------------------------------------------------------------------------- */