kingkevin
/
esp32-s2_dfu
1
0
Fork 0
Code Issues Releases Activity

Add handling for NAK response

This commit is contained in:
kkitayam 2022-01-10 23:50:32 +09:00
parent cdab869472
commit cc06a3585e
1 changed files with 230 additions and 127 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

357
src/portable/nxp/khci/hcd_khci.c
View File

@ -93,12 +93,11 @@ typedef struct TU_ATTR_PACKED
uint32_t : 0;
};
};
uint8_t *buffer;
uint16_t length;
uint16_t remaining;
} endpoint_state_t;
TU_VERIFY_STATIC( sizeof(endpoint_state_t) == 8, "size is not correct" );
typedef struct TU_ATTR_PACKED
{
uint8_t dev_addr;
@ -112,19 +111,24 @@ typedef struct TU_ATTR_PACKED
uint8_t : 0;
};
};
uint8_t *buffer;
uint16_t length;
uint16_t remaining;
} pipe_state_t;
typedef struct
{
union {
/* [#EP][OUT,IN][EVEN,ODD] */
buffer_descriptor_t bdt[16][2][2];
uint16_t bda[512];
/* [OUT,IN][EVEN,ODD] */
buffer_descriptor_t bdt[2][2];
uint16_t bda[2*2];
};
endpoint_state_t endpoint[2];
pipe_state_t pipe[HCD_MAX_XFER];
bool need_reset; /* The device has not been reset after connection. */
pipe_state_t pipe[HCD_MAX_XFER * 2];
uint32_t in_progress; /* Bitmap. Each bit indicates that a transfer of the corresponding pipe is in progress */
uint32_t pending; /* Bitmap. Each bit indicates that a transfer of the corresponding pipe will be resume the next frame */
bool need_reset; /* The device has not been reset after connection. */
} hcd_data_t;
//--------------------------------------------------------------------+
@ -132,15 +136,13 @@ typedef struct
//--------------------------------------------------------------------+
// BDT(Buffer Descriptor Table) must be 256-byte aligned
CFG_TUSB_MEM_SECTION TU_ATTR_ALIGNED(512) static hcd_data_t _hcd;
TU_VERIFY_STATIC( sizeof(_hcd.bdt) == 512, "size is not correct" );
//CFG_TUSB_MEM_SECTION TU_ATTR_ALIGNED(4) static uint8_t _rx_buf[1024];
int find_pipe(uint8_t dev_addr, uint8_t ep_addr)
{
/* Find the target pipe */
int num;
if (0 == tu_edpt_number(ep_addr)) ep_addr = 0;
for (num = 0; num < HCD_MAX_XFER; ++num) {
for (num = 0; num < HCD_MAX_XFER * 2; ++num) {
pipe_state_t *p = &_hcd.pipe[num];
if ((p->dev_addr == dev_addr) && (p->ep_addr == ep_addr))
return num;
@ -148,37 +150,129 @@ int find_pipe(uint8_t dev_addr, uint8_t ep_addr)
return -1;
}
static int prepare_packets(int pipenum,
uint_fast8_t dir_in, uint8_t* buffer,
uint_fast16_t total_bytes)
static int prepare_packets(int pipenum)
{
const unsigned dir_tx = dir_in ? 0 : 1;
endpoint_state_t *ep = &_hcd.endpoint[dir_tx];
buffer_descriptor_t *bd = &_hcd.bdt[0][dir_tx][ep->odd];
TU_ASSERT(0 == bd->own, 0);
pipe_state_t *pipe = &_hcd.pipe[pipenum];
unsigned const dir_tx = tu_edpt_dir(pipe->ep_addr) ? 0 : 1;
endpoint_state_t *ep = &_hcd.endpoint[dir_tx];
unsigned const odd = ep->odd;
buffer_descriptor_t *bd = _hcd.bdt[dir_tx];
TU_ASSERT(0 == bd[odd].own, -1);
ep->pipenum = pipenum;
ep->length = total_bytes;
ep->remaining = total_bytes;
// TU_LOG1(" %p dir %d odd %d data %d\n", &bd[odd], dir_tx, odd, pipe->data);
int num_pkts = 0; /* The number of prepared packets */
const unsigned mps = _hcd.pipe[pipenum].max_packet_size;
if (total_bytes > mps) {
buffer_descriptor_t *next = ep->odd ? bd - 1: bd + 1;
ep->pipenum = pipenum;
bd[odd ].data = pipe->data;
bd[odd ^ 1].data = pipe->data ^ 1;
bd[odd ^ 1].own = 0;
/* reset values for a next transfer */
int num_tokens = 0; /* The number of prepared packets */
unsigned const mps = pipe->max_packet_size;
unsigned const rem = pipe->remaining;
if (rem > mps) {
/* When total_bytes is greater than the max packet size,
* it prepares to the next transfer to avoid NAK in advance. */
next->bc = total_bytes >= 2 * mps ? mps: total_bytes - mps;
next->addr = buffer + mps;
next->own = 1;
++num_pkts;
bd[odd ^ 1].bc = rem >= 2 * mps ? mps: rem - mps;
bd[odd ^ 1].addr = pipe->buffer + mps;
bd[odd ^ 1].own = 1;
if (dir_tx) ++num_tokens;
}
bd->bc = total_bytes >= mps ? mps: total_bytes;
bd->addr = buffer;
bd[odd].bc = rem >= mps ? mps: rem;
bd[odd].addr = pipe->buffer;
__DSB();
bd->own = 1; /* This bit must be set last */
++num_pkts;
// TU_LOG1("BD pipe=%d %d %lx %x\n", pipenum, num_pkts, bd->head, (uintptr_t)bd->addr);
return num_pkts;
bd[odd].own = 1; /* This bit must be set last */
++num_tokens;
return num_tokens;
}
static int select_next_pipenum(int pipenum)
{
unsigned wip = _hcd.in_progress & ~_hcd.pending;
if (!wip) return -1;
unsigned msk = TU_GENMASK(31, pipenum);
int next = __builtin_ctz(wip & msk);
if (next) return next;
msk = TU_GENMASK(pipenum, 0);
next = __builtin_ctz(wip & msk);
return next;
}
/* When transfer is completed, return true. */
static bool continue_transfer(int pipenum, buffer_descriptor_t *bd)
{
pipe_state_t *pipe = &_hcd.pipe[pipenum];
unsigned const bc = bd->bc;
unsigned const rem = pipe->remaining - bc;
pipe->remaining = rem;
if (rem && bc == pipe->max_packet_size) {
int const next_rem = rem - pipe->max_packet_size;
if (next_rem > 0) {
/* Prepare to the after next transfer */
bd->addr += pipe->max_packet_size * 2;
bd->bc = next_rem > pipe->max_packet_size ? pipe->max_packet_size: next_rem;
__DSB();
bd->own = 1; /* This bit must be set last */
while (KHCI->CTL & USB_CTL_TXSUSPENDTOKENBUSY_MASK) ;
KHCI->TOKEN = KHCI->TOKEN; /* Queue the same token as the last */
} else if (TUSB_DIR_IN == tu_edpt_dir(pipe->ep_addr)) { /* IN */
while (KHCI->CTL & USB_CTL_TXSUSPENDTOKENBUSY_MASK) ;
KHCI->TOKEN = KHCI->TOKEN;
}
return true;
}
pipe->data = bd->data ^ 1;
return false;
}
static bool resume_transfer(int pipenum)
{
int num_tokens = prepare_packets(pipenum);
TU_ASSERT(0 <= num_tokens);
const unsigned ie = NVIC_GetEnableIRQ(USB0_IRQn);
NVIC_DisableIRQ(USB0_IRQn);
pipe_state_t *pipe = &_hcd.pipe[pipenum];
unsigned flags = KHCI->ENDPOINT[0].ENDPT & USB_ENDPT_HOSTWOHUB_MASK;
flags |= USB_ENDPT_EPRXEN_MASK | USB_ENDPT_EPTXEN_MASK;
switch (pipe->xfer) {
case TUSB_XFER_CONTROL:
flags |= USB_ENDPT_EPHSHK_MASK;
break;
case TUSB_XFER_ISOCHRONOUS:
flags |= USB_ENDPT_EPCTLDIS_MASK | USB_ENDPT_RETRYDIS_MASK;
break;
default:
flags |= USB_ENDPT_EPHSHK_MASK | USB_ENDPT_EPCTLDIS_MASK | USB_ENDPT_RETRYDIS_MASK;
break;
}
// TU_LOG1(" resume pipenum %d flags %x\n", pipenum, flags);
KHCI->ENDPOINT[0].ENDPT = flags;
KHCI->ADDR = (KHCI->ADDR & USB_ADDR_LSEN_MASK) | pipe->dev_addr;
unsigned const token = tu_edpt_number(pipe->ep_addr) |
((tu_edpt_dir(pipe->ep_addr) ? TOK_PID_IN: TOK_PID_OUT) << USB_TOKEN_TOKENPID_SHIFT);
do {
while (KHCI->CTL & USB_CTL_TXSUSPENDTOKENBUSY_MASK) ;
KHCI->TOKEN = token;
} while (--num_tokens);
if (ie) NVIC_EnableIRQ(USB0_IRQn);
return true;
}
static void suspend_transfer(int pipenum, buffer_descriptor_t *bd)
{
pipe_state_t *pipe = &_hcd.pipe[pipenum];
pipe->buffer = bd->addr;
pipe->data = bd->data;
if (TUSB_XFER_INTERRUPT == pipe->xfer) {
_hcd.pending |= TU_BIT(pipenum);
KHCI->INTEN |= USB_ISTAT_SOFTOK_MASK;
}
}
static void process_tokdne(uint8_t rhport)
@ -186,13 +280,9 @@ static void process_tokdne(uint8_t rhport)
(void)rhport;
const unsigned s = KHCI->STAT;
KHCI->ISTAT = USB_ISTAT_TOKDNE_MASK; /* fetch the next token if received */
uint8_t const epnum = (s >> USB_STAT_ENDP_SHIFT);
TU_ASSERT(0 == epnum,);
uint8_t const dir_in = (s & USB_STAT_TX_MASK) ? TUSB_DIR_OUT: TUSB_DIR_IN;
unsigned const odd = (s & USB_STAT_ODD_MASK) ? 1 : 0;
// TU_LOG1("TOKDNE %x\n", s);
buffer_descriptor_t *bd = (buffer_descriptor_t *)&_hcd.bda[s];
endpoint_state_t *ep = &_hcd.endpoint[s >> 3];
@ -207,48 +297,40 @@ static void process_tokdne(uint8_t rhport)
/* Update the odd variable to prepare for the next transfer */
ep->odd = odd ^ 1;
const unsigned bc = bd->bc;
const unsigned remaining = ep->remaining - bc;
pipe_state_t *pipe = &_hcd.pipe[ep->pipenum];
int pipenum = ep->pipenum;
int next_pipenum;
// TU_LOG1("TOKDNE %x PID %x pipe %d\n", s, pid, pipenum);
// TU_LOG1(" pid %x bc %x remaining %d\n", pid, bc, remaining);
if ((TOK_PID_DATA0 == pid) || (TOK_PID_DATA1 == pid) || (TOK_PID_ACK == pid)) {
/* Go on the next packet transfer */
if (remaining && bc == pipe->max_packet_size) {
ep->remaining = remaining;
const int next_remaining = remaining - pipe->max_packet_size;
if (next_remaining > 0) {
/* Prepare to the after next transfer */
bd->addr += pipe->max_packet_size * 2;
bd->bc = next_remaining > pipe->max_packet_size ? pipe->max_packet_size: next_remaining;
__DSB();
bd->own = 1; /* This bit must be set last */
while (KHCI->CTL & USB_CTL_TXSUSPENDTOKENBUSY_MASK) ;
KHCI->TOKEN = KHCI->TOKEN; /* Queue the same token as the last */
} else if (dir_in) {
KHCI->TOKEN = KHCI->TOKEN;
}
return;
}
}
const unsigned length = ep->length;
xfer_result_t result;
switch (pid) {
default:
if (continue_transfer(pipenum, bd))
return;
result = XFER_RESULT_SUCCESS;
break;
case TOK_PID_STALL:
result = XFER_RESULT_STALLED;
break;
case TOK_PID_NAK:
case TOK_PID_ERR:
suspend_transfer(pipenum, bd);
next_pipenum = select_next_pipenum(pipenum);
if (0 <= next_pipenum)
resume_transfer(next_pipenum);
return;
case TOK_PID_STALL:
result = XFER_RESULT_STALLED;
break;
case TOK_PID_BUSTO:
result = XFER_RESULT_FAILED;
break;
}
_hcd.in_progress &= ~TU_BIT(pipenum);
pipe_state_t *pipe = &_hcd.pipe[ep->pipenum];
hcd_event_xfer_complete(pipe->dev_addr,
tu_edpt_addr(KHCI->TOKEN & USB_TOKEN_TOKENENDPT_MASK, dir_in),
length - remaining, result, true);
pipe->length - pipe->remaining,
result, true);
next_pipenum = select_next_pipenum(pipenum);
if (0 <= next_pipenum)
resume_transfer(next_pipenum);
}
static void process_attach(uint8_t rhport)
@ -264,6 +346,7 @@ static void process_attach(uint8_t rhport)
static void process_bus_reset(uint8_t rhport)
{
KHCI->ISTAT = USB_ISTAT_TOKDNE_MASK;
KHCI->USBCTRL &= ~USB_USBCTRL_SUSP_MASK;
KHCI->CTL &= ~USB_CTL_USBENSOFEN_MASK;
KHCI->ADDR = 0;
@ -271,7 +354,9 @@ static void process_bus_reset(uint8_t rhport)
hcd_event_device_remove(rhport, true);
buffer_descriptor_t *bd = _hcd.bdt[0][0];
_hcd.in_progress = 0;
_hcd.pending = 0;
buffer_descriptor_t *bd = &_hcd.bdt[0][0];
for (unsigned i = 0; i < 2; ++i, ++bd) {
bd->head = 0;
}
@ -301,12 +386,15 @@ bool hcd_init(uint8_t rhport)
KHCI->CTL &= ~USB_CTL_ODDRST_MASK;
KHCI->SOFTHLD = 74; /* for 64-byte packets */
// KHCI->SOFTHLD = 144; /* for low speed 8-byte packets */
KHCI->CTL = USB_CTL_HOSTMODEEN_MASK | USB_CTL_SE0_MASK;
KHCI->USBCTRL = USB_USBCTRL_PDE_MASK;
NVIC_ClearPendingIRQ(USB0_IRQn);
KHCI->INTEN = USB_INTEN_ATTACHEN_MASK | USB_INTEN_TOKDNEEN_MASK |
USB_INTEN_USBRSTEN_MASK | USB_INTEN_ERROREN_MASK | USB_INTEN_STALLEN_MASK;
KHCI->ERREN = 0xff;
return true;
}
@ -371,12 +459,15 @@ tusb_speed_t hcd_port_speed_get(uint8_t rhport)
void hcd_device_close(uint8_t rhport, uint8_t dev_addr)
{
(void)rhport;
const unsigned ie = NVIC_GetEnableIRQ(USB0_IRQn);
NVIC_DisableIRQ(USB0_IRQn);
pipe_state_t *p = &_hcd.pipe[0];
pipe_state_t *end = &_hcd.pipe[HCD_MAX_XFER];
pipe_state_t *end = &_hcd.pipe[HCD_MAX_XFER * 2];
for (;p != end; ++p) {
if (p->dev_addr == dev_addr)
tu_memclr(p, sizeof(*p));
}
if (ie) NVIC_EnableIRQ(USB0_IRQn);
}
//--------------------------------------------------------------------+
@ -386,34 +477,30 @@ bool hcd_setup_send(uint8_t rhport, uint8_t dev_addr, uint8_t const setup_packet
{
(void)rhport;
// TU_LOG1("SETUP %u\n", dev_addr);
const unsigned rx_odd = _hcd.endpoint[0].odd;
const unsigned tx_odd = _hcd.endpoint[1].odd;
TU_ASSERT(0 == _hcd.bdt[0][0][tx_odd].own);
TU_ASSERT(0 == (_hcd.in_progress & TU_BIT(0)));
int num = find_pipe(dev_addr, 0);
if (num < 0) return false;
int pipenum = find_pipe(dev_addr, 0);
if (pipenum < 0) return false;
const unsigned ie = NVIC_GetEnableIRQ(USB0_IRQn);
NVIC_DisableIRQ(USB0_IRQn);
pipe_state_t *pipe = &_hcd.pipe[pipenum];
pipe[0].data = 0;
pipe[0].buffer = (uint8_t*)(uintptr_t)setup_packet;
pipe[0].length = 8;
pipe[0].remaining = 8;
pipe[1].data = 1;
_hcd.bdt[0][0][rx_odd ].data = 1;
_hcd.bdt[0][0][rx_odd ^ 1].data = 0;
_hcd.bdt[0][1][tx_odd ].data = 0;
_hcd.bdt[0][1][tx_odd ^ 1].data = 1;
if (1 != prepare_packets(pipenum))
return false;
_hcd.in_progress |= TU_BIT(pipenum);
unsigned hostwohub = KHCI->ENDPOINT[0].ENDPT & USB_ENDPT_HOSTWOHUB_MASK;
KHCI->ENDPOINT[0].ENDPT = hostwohub |
USB_ENDPT_EPHSHK_MASK | USB_ENDPT_EPRXEN_MASK | USB_ENDPT_EPTXEN_MASK;
bool ret = false;
if (prepare_packets(num, TUSB_DIR_OUT, (void*)(uintptr_t)setup_packet, 8)) {
KHCI->ADDR = (KHCI->ADDR & USB_ADDR_LSEN_MASK) | dev_addr;
while (KHCI->CTL & USB_CTL_TXSUSPENDTOKENBUSY_MASK) ;
KHCI->TOKEN = (TOK_PID_SETUP << USB_TOKEN_TOKENPID_SHIFT);
ret = true;
}
if (ie) NVIC_EnableIRQ(USB0_IRQn);
return ret;
KHCI->ADDR = (KHCI->ADDR & USB_ADDR_LSEN_MASK) | dev_addr;
while (KHCI->CTL & USB_CTL_TXSUSPENDTOKENBUSY_MASK) ;
KHCI->TOKEN = (TOK_PID_SETUP << USB_TOKEN_TOKENPID_SHIFT);
return true;
}
bool hcd_edpt_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_endpoint_t const * ep_desc)
@ -423,9 +510,10 @@ bool hcd_edpt_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_endpoint_t const
// TU_LOG1("O %u %x\n", dev_addr, ep_addr);
/* Find a free pipe */
pipe_state_t *p = &_hcd.pipe[0];
pipe_state_t *end = &_hcd.pipe[HCD_MAX_XFER * 2];
if (dev_addr || ep_addr) {
pipe_state_t *end = &_hcd.pipe[HCD_MAX_XFER];
for (++p; p < end && (p->dev_addr || p->ep_addr); ++p) ;
p += 2;
for (; p < end && (p->dev_addr || p->ep_addr); ++p) ;
if (p == end) return false;
}
p->dev_addr = dev_addr;
@ -433,45 +521,39 @@ bool hcd_edpt_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_endpoint_t const
p->max_packet_size = ep_desc->wMaxPacketSize;
p->xfer = ep_desc->bmAttributes.xfer;
p->data = 0;
if (!ep_addr) {
/* Open one more pipe for Control IN transfer */
TU_ASSERT(TUSB_XFER_CONTROL == p->xfer);
pipe_state_t *q = p + 1;
TU_ASSERT(!q->dev_addr && !q->ep_addr);
q->dev_addr = dev_addr;
q->ep_addr = tu_edpt_addr(0, TUSB_DIR_IN);
q->max_packet_size = ep_desc->wMaxPacketSize;
q->xfer = ep_desc->bmAttributes.xfer;
q->data = 1;
}
return true;
}
bool hcd_edpt_xfer(uint8_t rhport, uint8_t dev_addr, uint8_t ep_addr, uint8_t * buffer, uint16_t buflen)
{
(void)rhport;
// TU_LOG1("X %u %x %d\n", dev_addr, ep_addr, buflen);
const unsigned dir_in = tu_edpt_dir(ep_addr);
const unsigned odd = _hcd.endpoint[dir_in ^ 1].odd;
buffer_descriptor_t *bd = _hcd.bdt[0][dir_in ^ 1];
TU_ASSERT(0 == bd[odd].own);
// TU_LOG1("X %u %x %x %d\n", dev_addr, ep_addr, (uintptr_t)buffer, buflen);
int num = find_pipe(dev_addr, ep_addr);
if (num < 0) return false;
int pipenum = find_pipe(dev_addr, ep_addr);
TU_ASSERT(0 <= pipenum);
unsigned flags = USB_ENDPT_EPHSHK_MASK | USB_ENDPT_EPRXEN_MASK | USB_ENDPT_EPTXEN_MASK;
if (tu_edpt_number(ep_addr)) {
pipe_state_t *p = &_hcd.pipe[num];
bd[odd ].data = p->data;
bd[odd ^ 1].data = p->data ^ 1;
bd[odd ^ 1].own = 0;
flags |= USB_ENDPT_EPCTLDIS_MASK;
/* Disable retry for a interrupt transfer. */
if (TUSB_XFER_INTERRUPT == p->xfer)
flags |= USB_ENDPT_RETRYDIS_MASK;
}
unsigned hostwohub = KHCI->ENDPOINT[0].ENDPT & USB_ENDPT_HOSTWOHUB_MASK;
KHCI->ENDPOINT[0].ENDPT = hostwohub | flags;
int num_pkts = prepare_packets(num, dir_in, buffer, buflen);
if (!num_pkts) return false;
KHCI->ADDR = (KHCI->ADDR & USB_ADDR_LSEN_MASK) | dev_addr;
const unsigned token = tu_edpt_number(ep_addr) |
((dir_in ? TOK_PID_IN: TOK_PID_OUT) << USB_TOKEN_TOKENPID_SHIFT);
const unsigned ie = NVIC_GetEnableIRQ(USB0_IRQn);
TU_ASSERT(0 == (_hcd.in_progress & TU_BIT(pipenum)));
unsigned const ie = NVIC_GetEnableIRQ(USB0_IRQn);
unsigned const wip = _hcd.in_progress;
NVIC_DisableIRQ(USB0_IRQn);
do {
while (KHCI->CTL & USB_CTL_TXSUSPENDTOKENBUSY_MASK) ;
KHCI->TOKEN = token;
} while (--num_pkts && !dir_in);
pipe_state_t *pipe = &_hcd.pipe[pipenum];
pipe->buffer = buffer;
pipe->length = buflen;
pipe->remaining = buflen;
_hcd.in_progress = wip | TU_BIT(pipenum);
if (0 == (wip & ~_hcd.pending))
resume_transfer(pipenum);
if (ie) NVIC_EnableIRQ(USB0_IRQn);
return true;
}
@ -497,21 +579,42 @@ void hcd_int_handler(uint8_t rhport)
// TU_LOG1("S %lx\n", is);
/* clear disabled interrupts */
KHCI->ISTAT = is & ~msk & ~USB_ISTAT_TOKDNE_MASK;
KHCI->ISTAT = (is & ~msk & ~USB_ISTAT_TOKDNE_MASK) | USB_ISTAT_SOFTOK_MASK;
is &= msk;
if (is & USB_ISTAT_ERROR_MASK) {
unsigned err = KHCI->ERRSTAT;
if (err) {
TU_LOG1(" ERR %x\n", err);
KHCI->ERRSTAT = err;
} else {
KHCI->INTEN &= ~USB_ISTAT_ERROR_MASK;
}
}
if (is & USB_ISTAT_USBRST_MASK) {
KHCI->INTEN = (msk & ~USB_INTEN_USBRSTEN_MASK) | USB_INTEN_ATTACHEN_MASK;
process_bus_reset(rhport);
return;
}
if (is & USB_ISTAT_ATTACH_MASK) {
KHCI->INTEN = (msk & ~USB_INTEN_ATTACHEN_MASK) | USB_INTEN_USBRSTEN_MASK;
_hcd.need_reset = true;
process_attach(rhport);
}
if (is & USB_ISTAT_USBRST_MASK) {
KHCI->INTEN = (msk & ~USB_INTEN_USBRSTEN_MASK) | USB_INTEN_ATTACHEN_MASK;
process_bus_reset(rhport);
return;
}
if (is & USB_ISTAT_STALL_MASK) {
KHCI->ISTAT = USB_ISTAT_STALL_MASK;
}
if (is & USB_ISTAT_SOFTOK_MASK) {
msk &= ~USB_ISTAT_SOFTOK_MASK;
KHCI->INTEN = msk;
if (_hcd.pending) {
int pipenum = __builtin_ctz(_hcd.pending);
_hcd.pending = 0;
resume_transfer(pipenum);
}
}
if (is & USB_ISTAT_TOKDNE_MASK) {
process_tokdne(rhport);
}