coreboot-kgpe-d16/payloads/libpayload/drivers/usb/uhci.c

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/*
* This file is part of the libpayload project.
*
* Copyright (C) 2008-2010 coresystems GmbH
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
//#define USB_DEBUG
#include <arch/virtual.h>
#include <usb/usb.h>
#include "uhci.h"
#include "uhci_private.h"
static void uhci_start (hci_t *controller);
static void uhci_stop (hci_t *controller);
static void uhci_reset (hci_t *controller);
static void uhci_shutdown (hci_t *controller);
static int uhci_bulk (endpoint_t *ep, int size, u8 *data, int finalize);
static int uhci_control (usbdev_t *dev, direction_t dir, int drlen, void *devreq,
int dalen, u8 *data);
static void* uhci_create_intr_queue (endpoint_t *ep, int reqsize, int reqcount, int reqtiming);
static void uhci_destroy_intr_queue (endpoint_t *ep, void *queue);
static u8* uhci_poll_intr_queue (void *queue);
#if 0
/* dump uhci */
static void
uhci_dump (hci_t *controller)
{
usb_debug ("dump:\nUSBCMD: %x\n", uhci_reg_read16 (controller, USBCMD));
usb_debug ("USBSTS: %x\n", uhci_reg_read16 (controller, USBSTS));
usb_debug ("USBINTR: %x\n", uhci_reg_read16 (controller, USBINTR));
usb_debug ("FRNUM: %x\n", uhci_reg_read16 (controller, FRNUM));
usb_debug ("FLBASEADD: %x\n", uhci_reg_read32 (controller, FLBASEADD));
usb_debug ("SOFMOD: %x\n", uhci_reg_read8 (controller, SOFMOD));
usb_debug ("PORTSC1: %x\n", uhci_reg_read16 (controller, PORTSC1));
usb_debug ("PORTSC2: %x\n", uhci_reg_read16 (controller, PORTSC2));
}
#endif
static void td_dump(td_t *td)
{
usb_debug("+---------------------------------------------------+\n");
if ((td->token & TD_PID_MASK) == UHCI_SETUP)
usb_debug("|..[SETUP]..........................................|\n");
else if ((td->token & TD_PID_MASK) == UHCI_IN)
usb_debug("|..[IN].............................................|\n");
else if ((td->token & TD_PID_MASK) == UHCI_OUT)
usb_debug("|..[OUT]............................................|\n");
else
usb_debug("|..[]...............................................|\n");
usb_debug("|:|============ UHCI TD at [0x%08lx] ==========|:|\n", virt_to_phys(td));
usb_debug("|:+-----------------------------------------------+:|\n");
usb_debug("|:| Next TD/QH [0x%08lx] |:|\n", td->ptr & ~0xFUL);
usb_debug("|:+-----------------------------------------------+:|\n");
usb_debug("|:| Depth/Breath [%lx] | QH/TD [%lx] | TERMINATE [%lx] |:|\n",
(td->ptr & (1UL << 2)) >> 2, (td->ptr & (1UL << 1)) >> 1, td->ptr & 1UL);
usb_debug("|:+-----------------------------------------------+:|\n");
usb_debug("|:| T | Maximum Length | [%04lx] |:|\n", (td->token & (0x7FFUL << 21)) >> 21);
usb_debug("|:| O | PID CODE | [%04lx] |:|\n", td->token & 0xFF);
usb_debug("|:| K | Endpoint | [%04lx] |:|\n", (td->token & TD_EP_MASK) >> TD_EP_SHIFT);
usb_debug("|:| E | Device Address | [%04lx] |:|\n", (td->token & (0x7FUL << 8)) >> 8);
usb_debug("|:| N | Data Toggle | [%lx] |:|\n", (td->token & (1UL << 19)) >> 19);
usb_debug("|:+-----------------------------------------------+:|\n");
usb_debug("|:| C | Short Packet Detector | [%lx] |:|\n", (td->ctrlsts & (1UL << 29)) >> 29);
usb_debug("|:| O | Error Counter | [%lx] |:|\n",
(td->ctrlsts & (3UL << TD_COUNTER_SHIFT)) >> TD_COUNTER_SHIFT);
usb_debug("|:| N | Low Speed Device | [%lx] |:|\n", (td->ctrlsts & (1UL << 26)) >> 26);
usb_debug("|:| T | Isochronous Select | [%lx] |:|\n", (td->ctrlsts & (1UL << 25)) >> 25);
usb_debug("|:| R | Interrupt on Complete (IOC) | [%lx] |:|\n", (td->ctrlsts & (1UL << 24)) >> 24);
usb_debug("|:+ O ----------------------------------------+:|\n");
usb_debug("|:| L | Active | [%lx] |:|\n", (td->ctrlsts & (1UL << 23)) >> 23);
usb_debug("|:| & | Stalled | [%lx] |:|\n", (td->ctrlsts & (1UL << 22)) >> 22);
usb_debug("|:| S | Data Buffer Error | [%lx] |:|\n", (td->ctrlsts & (1UL << 21)) >> 21);
usb_debug("|:| T | Bubble Detected | [%lx] |:|\n", (td->ctrlsts & (1UL << 20)) >> 20);
usb_debug("|:| A | NAK Received | [%lx] |:|\n", (td->ctrlsts & (1UL << 19)) >> 19);
usb_debug("|:| T | CRC/Timeout Error | [%lx] |:|\n", (td->ctrlsts & (1UL << 18)) >> 18);
usb_debug("|:| U | Bitstuff Error | [%lx] |:|\n", (td->ctrlsts & (1UL << 17)) >> 17);
usb_debug("|:| S ----------------------------------------|:|\n");
usb_debug("|:| | Actual Length | [%04lx] |:|\n", td->ctrlsts & 0x7FFUL);
usb_debug("|:+-----------------------------------------------+:|\n");
usb_debug("|:| Buffer pointer [0x%08lx] |:|\n", td->bufptr);
usb_debug("|:|-----------------------------------------------|:|\n");
usb_debug("|...................................................|\n");
usb_debug("+---------------------------------------------------+\n");
}
static void
uhci_reset (hci_t *controller)
{
/* reset */
uhci_reg_write16 (controller, USBCMD, 4); /* Global Reset */
mdelay (50); /* uhci spec 2.1.1: at least 10ms */
uhci_reg_write16 (controller, USBCMD, 0);
mdelay (10);
uhci_reg_write16 (controller, USBCMD, 2); /* Host Controller Reset */
/* wait for controller to finish reset */
/* TOTEST: how long to wait? 100ms for now */
int timeout = 200; /* time out after 200 * 500us == 100ms */
while (((uhci_reg_read16 (controller, USBCMD) & 2) != 0) && timeout--)
udelay (500);
if (timeout < 0)
usb_debug ("Warning: uhci: host controller reset timed out.\n");
}
static void
uhci_reinit (hci_t *controller)
{
uhci_reg_write32 (controller, FLBASEADD,
(u32) virt_to_phys (UHCI_INST (controller)->
framelistptr));
//usb_debug ("framelist at %p\n",UHCI_INST(controller)->framelistptr);
/* disable irqs */
uhci_reg_write16 (controller, USBINTR, 0);
/* reset framelist index */
uhci_reg_write16 (controller, FRNUM, 0);
uhci_reg_write16(controller, USBCMD,
uhci_reg_read16(controller, USBCMD) | 0xc0); // max packets, configure flag
uhci_start (controller);
}
hci_t *
uhci_init (pcidev_t addr)
{
int i;
u16 reg16;
hci_t *controller = new_controller ();
if (!controller)
fatal("Could not create USB controller instance.\n");
controller->instance = malloc (sizeof (uhci_t));
if(!controller->instance)
fatal("Not enough memory creating USB controller instance.\n");
controller->type = UHCI;
controller->start = uhci_start;
controller->stop = uhci_stop;
controller->reset = uhci_reset;
controller->init = uhci_reinit;
controller->shutdown = uhci_shutdown;
controller->bulk = uhci_bulk;
controller->control = uhci_control;
controller->create_intr_queue = uhci_create_intr_queue;
controller->destroy_intr_queue = uhci_destroy_intr_queue;
controller->poll_intr_queue = uhci_poll_intr_queue;
for (i = 0; i < 128; i++) {
controller->devices[i] = 0;
}
init_device_entry (controller, 0);
UHCI_INST (controller)->roothub = controller->devices[0];
controller->bus_address = addr;
controller->reg_base = pci_read_config32 (controller->bus_address, 0x20) & ~1; /* ~1 clears the register type indicator that is set to 1 for IO space */
/* kill legacy support handler */
uhci_stop (controller);
mdelay (1);
uhci_reg_write16 (controller, USBSTS, 0x3f);
reg16 = pci_read_config16(controller->bus_address, 0xc0);
reg16 &= 0xdf80;
pci_write_config16 (controller->bus_address, 0xc0, reg16);
UHCI_INST (controller)->framelistptr = memalign (0x1000, 1024 * sizeof (flistp_t)); /* 4kb aligned to 4kb */
if (! UHCI_INST (controller)->framelistptr)
fatal("Not enough memory for USB frame list pointer.\n");
memset (UHCI_INST (controller)->framelistptr, 0,
1024 * sizeof (flistp_t));
/* According to the *BSD UHCI code, this one is needed on some
PIIX chips, because otherwise they misbehave. It must be
added to the last chain.
FIXME: this leaks, if the driver should ever be reinited
for some reason. Not a problem now.
*/
td_t *antiberserk = memalign(16, sizeof(td_t));
if (!antiberserk)
fatal("Not enough memory for chipset workaround.\n");
memset(antiberserk, 0, sizeof(td_t));
UHCI_INST (controller)->qh_prei = memalign (16, sizeof (qh_t));
UHCI_INST (controller)->qh_intr = memalign (16, sizeof (qh_t));
UHCI_INST (controller)->qh_data = memalign (16, sizeof (qh_t));
UHCI_INST (controller)->qh_last = memalign (16, sizeof (qh_t));
if (! UHCI_INST (controller)->qh_prei ||
! UHCI_INST (controller)->qh_intr ||
! UHCI_INST (controller)->qh_data ||
! UHCI_INST (controller)->qh_last)
fatal("Not enough memory for USB controller queues.\n");
UHCI_INST (controller)->qh_prei->headlinkptr =
virt_to_phys (UHCI_INST (controller)->qh_intr) | FLISTP_QH;
UHCI_INST (controller)->qh_prei->elementlinkptr = 0 | FLISTP_TERMINATE;
UHCI_INST (controller)->qh_intr->headlinkptr =
virt_to_phys (UHCI_INST (controller)->qh_data) | FLISTP_QH;
UHCI_INST (controller)->qh_intr->elementlinkptr = 0 | FLISTP_TERMINATE;
UHCI_INST (controller)->qh_data->headlinkptr =
virt_to_phys (UHCI_INST (controller)->qh_last) | FLISTP_QH;
UHCI_INST (controller)->qh_data->elementlinkptr = 0 | FLISTP_TERMINATE;
UHCI_INST (controller)->qh_last->headlinkptr = virt_to_phys (UHCI_INST (controller)->qh_data) | FLISTP_TERMINATE;
UHCI_INST (controller)->qh_last->elementlinkptr = virt_to_phys (antiberserk) | FLISTP_TERMINATE;
for (i = 0; i < 1024; i++) {
UHCI_INST (controller)->framelistptr[i] =
virt_to_phys (UHCI_INST (controller)->qh_prei) | FLISTP_QH;
}
controller->devices[0]->controller = controller;
controller->devices[0]->init = uhci_rh_init;
controller->devices[0]->init (controller->devices[0]);
uhci_reset (controller);
uhci_reinit (controller);
return controller;
}
static void
uhci_shutdown (hci_t *controller)
{
if (controller == 0)
return;
detach_controller (controller);
UHCI_INST (controller)->roothub->destroy (UHCI_INST (controller)->
roothub);
uhci_reg_write16(controller, USBCMD,
uhci_reg_read16(controller, USBCMD) & 0); // stop work
free (UHCI_INST (controller)->framelistptr);
free (UHCI_INST (controller)->qh_prei);
free (UHCI_INST (controller)->qh_intr);
free (UHCI_INST (controller)->qh_data);
free (UHCI_INST (controller)->qh_last);
free (UHCI_INST (controller));
free (controller);
}
static void
uhci_start (hci_t *controller)
{
uhci_reg_write16(controller, USBCMD,
uhci_reg_read16(controller, USBCMD) | 1); // start work on schedule
}
static void
uhci_stop (hci_t *controller)
{
uhci_reg_write16(controller, USBCMD,
uhci_reg_read16(controller, USBCMD) & ~1); // stop work on schedule
}
#define GET_TD(x) ((void*)(((unsigned int)(x))&~0xf))
static td_t *
wait_for_completed_qh (hci_t *controller, qh_t *qh)
{
int timeout = 1000; /* max 30 ms. */
void *current = GET_TD (qh->elementlinkptr);
while (((qh->elementlinkptr & FLISTP_TERMINATE) == 0) && (timeout-- > 0)) {
if (current != GET_TD (qh->elementlinkptr)) {
current = GET_TD (qh->elementlinkptr);
timeout = 1000;
}
uhci_reg_write16(controller, USBSTS,
uhci_reg_read16(controller, USBSTS) | 0); // clear resettable registers
udelay (30);
}
return (GET_TD (qh->elementlinkptr) ==
0) ? 0 : GET_TD (phys_to_virt (qh->elementlinkptr));
}
static int
maxlen (int size)
{
return (size - 1) & 0x7ff;
}
static int
min (int a, int b)
{
if (a < b)
return a;
else
return b;
}
static int
uhci_control (usbdev_t *dev, direction_t dir, int drlen, void *devreq, int dalen,
unsigned char *data)
{
int endp = 0; /* this is control: always 0 */
int mlen = dev->endpoints[0].maxpacketsize;
int count = (2 + (dalen + mlen - 1) / mlen);
unsigned short req = ((unsigned short *) devreq)[0];
int i;
td_t *tds = memalign (16, sizeof (td_t) * count);
memset (tds, 0, sizeof (td_t) * count);
count--; /* to compensate for 0-indexed array */
for (i = 0; i < count; i++) {
tds[i].ptr = virt_to_phys (&tds[i + 1]) | TD_DEPTH_FIRST;
}
tds[count].ptr = 0 | TD_DEPTH_FIRST | TD_TERMINATE;
tds[0].token = UHCI_SETUP |
dev->address << TD_DEVADDR_SHIFT |
endp << TD_EP_SHIFT |
TD_TOGGLE_DATA0 |
maxlen(drlen) << TD_MAXLEN_SHIFT;
tds[0].bufptr = virt_to_phys (devreq);
tds[0].ctrlsts = (3 << TD_COUNTER_SHIFT) |
(dev->speed?TD_LOWSPEED:0) |
TD_STATUS_ACTIVE;
int toggle = 1;
for (i = 1; i < count; i++) {
switch (dir) {
case SETUP: tds[i].token = UHCI_SETUP; break;
case IN: tds[i].token = UHCI_IN; break;
case OUT: tds[i].token = UHCI_OUT; break;
}
tds[i].token |= dev->address << TD_DEVADDR_SHIFT |
endp << TD_EP_SHIFT |
maxlen (min (mlen, dalen)) << TD_MAXLEN_SHIFT |
toggle << TD_TOGGLE_SHIFT;
tds[i].bufptr = virt_to_phys (data);
tds[i].ctrlsts = (3 << TD_COUNTER_SHIFT) |
(dev->speed?TD_LOWSPEED:0) |
TD_STATUS_ACTIVE;
toggle ^= 1;
dalen -= mlen;
data += mlen;
}
tds[count].token = ((dir == OUT) ? UHCI_IN : UHCI_OUT) |
dev->address << TD_DEVADDR_SHIFT |
endp << TD_EP_SHIFT |
maxlen(0) << TD_MAXLEN_SHIFT |
TD_TOGGLE_DATA1;
tds[count].bufptr = 0;
tds[count].ctrlsts = (0 << TD_COUNTER_SHIFT) | /* as Linux 2.4.10 does */
(dev->speed?TD_LOWSPEED:0) |
TD_STATUS_ACTIVE;
UHCI_INST (dev->controller)->qh_data->elementlinkptr =
virt_to_phys (tds) & ~(FLISTP_QH | FLISTP_TERMINATE);
td_t *td = wait_for_completed_qh (dev->controller,
UHCI_INST (dev->controller)->
qh_data);
int result;
if (td == 0) {
result = 0;
} else {
usb_debug ("control packet, req %x\n", req);
td_dump (td);
result = 1;
}
free (tds);
return result;
}
static td_t *
create_schedule (int numpackets)
{
if (numpackets == 0)
return 0;
td_t *tds = memalign (16, sizeof (td_t) * numpackets);
memset (tds, 0, sizeof (td_t) * numpackets);
int i;
for (i = 0; i < numpackets; i++) {
tds[i].ptr = virt_to_phys (&tds[i + 1]) | TD_DEPTH_FIRST;
}
tds[numpackets - 1].ptr = 0 | TD_TERMINATE;
return tds;
}
static void
fill_schedule (td_t *td, endpoint_t *ep, int length, unsigned char *data,
int *toggle)
{
switch (ep->direction) {
case IN: td->token = UHCI_IN; break;
case OUT: td->token = UHCI_OUT; break;
case SETUP: td->token = UHCI_SETUP; break;
}
td->token |= ep->dev->address << TD_DEVADDR_SHIFT |
(ep->endpoint & 0xf) << TD_EP_SHIFT |
maxlen (length) << TD_MAXLEN_SHIFT |
(*toggle & 1) << TD_TOGGLE_SHIFT;
td->bufptr = virt_to_phys (data);
td->ctrlsts = ((ep->direction == SETUP?3:0) << TD_COUNTER_SHIFT) |
(ep->dev->speed?TD_LOWSPEED:0) |
TD_STATUS_ACTIVE;
*toggle ^= 1;
}
static int
run_schedule (usbdev_t *dev, td_t *td)
{
UHCI_INST (dev->controller)->qh_data->elementlinkptr =
virt_to_phys (td) & ~(FLISTP_QH | FLISTP_TERMINATE);
td = wait_for_completed_qh (dev->controller,
UHCI_INST (dev->controller)->qh_data);
if (td == 0) {
return 0;
} else {
td_dump (td);
return 1;
}
}
/* finalize == 1: if data is of packet aligned size, add a zero length packet */
static int
uhci_bulk (endpoint_t *ep, int size, u8 *data, int finalize)
{
int maxpsize = ep->maxpacketsize;
if (maxpsize == 0)
fatal("MaxPacketSize == 0!!!");
int numpackets = (size + maxpsize - 1) / maxpsize;
if (finalize && ((size % maxpsize) == 0)) {
numpackets++;
}
if (numpackets == 0)
return 0;
td_t *tds = create_schedule (numpackets);
int i = 0, toggle = ep->toggle;
while ((size > 0) || ((size == 0) && (finalize != 0))) {
fill_schedule (&tds[i], ep, min (size, maxpsize), data,
&toggle);
i++;
data += maxpsize;
size -= maxpsize;
}
if (run_schedule (ep->dev, tds) == 1) {
usb_debug("Stalled. Trying to clean up.\n");
clear_stall (ep);
free (tds);
return 1;
}
ep->toggle = toggle;
free (tds);
return 0;
}
typedef struct {
qh_t *qh;
td_t *tds;
td_t *last_td;
u8 *data;
int lastread;
int total;
int reqsize;
} intr_q;
/* create and hook-up an intr queue into device schedule */
static void*
uhci_create_intr_queue (endpoint_t *ep, int reqsize, int reqcount, int reqtiming)
{
u8 *data = malloc(reqsize*reqcount);
td_t *tds = memalign(16, sizeof(td_t) * reqcount);
qh_t *qh = memalign(16, sizeof(qh_t));
if (!data || !tds || !qh)
fatal("Not enough memory to create USB intr queue prerequisites.\n");
qh->elementlinkptr = virt_to_phys(tds);
intr_q *q = malloc(sizeof(intr_q));
if (!q)
fatal("Not enough memory to create USB intr queue.\n");
q->qh = qh;
q->tds = tds;
q->data = data;
q->lastread = 0;
q->total = reqcount;
q->reqsize = reqsize;
q->last_td = &tds[reqcount - 1];
memset (tds, 0, sizeof (td_t) * reqcount);
int i;
for (i = 0; i < reqcount; i++) {
tds[i].ptr = virt_to_phys (&tds[i + 1]);
switch (ep->direction) {
case IN: tds[i].token = UHCI_IN; break;
case OUT: tds[i].token = UHCI_OUT; break;
case SETUP: tds[i].token = UHCI_SETUP; break;
}
tds[i].token |= ep->dev->address << TD_DEVADDR_SHIFT |
(ep->endpoint & 0xf) << TD_EP_SHIFT |
maxlen (reqsize) << TD_MAXLEN_SHIFT |
(ep->toggle & 1) << TD_TOGGLE_SHIFT;
tds[i].bufptr = virt_to_phys (data);
tds[i].ctrlsts = (0 << TD_COUNTER_SHIFT) |
(ep->dev->speed?TD_LOWSPEED:0) |
TD_STATUS_ACTIVE;
ep->toggle ^= 1;
data += reqsize;
}
tds[reqcount - 1].ptr = 0 | TD_TERMINATE;
/* insert QH into framelist */
uhci_t *const uhcic = UHCI_INST(ep->dev->controller);
const u32 def_ptr = virt_to_phys(uhcic->qh_prei) | FLISTP_QH;
int nothing_placed = 1;
qh->headlinkptr = def_ptr;
for (i = 0; i < 1024; i += reqtiming) {
/* advance to the next free position */
while ((i < 1024) && (uhcic->framelistptr[i] != def_ptr)) ++i;
if (i < 1024) {
uhcic->framelistptr[i] = virt_to_phys(qh) | FLISTP_QH;
nothing_placed = 0;
}
}
if (nothing_placed) {
usb_debug("Error: Failed to place UHCI interrupt queue "
"head into framelist: no space left\n");
uhci_destroy_intr_queue(ep, q);
return NULL;
}
return q;
}
/* remove queue from device schedule, dropping all data that came in */
static void
uhci_destroy_intr_queue (endpoint_t *ep, void *q_)
{
intr_q *const q = (intr_q*)q_;
/* remove QH from framelist */
uhci_t *const uhcic = UHCI_INST(ep->dev->controller);
const u32 qh_ptr = virt_to_phys(q->qh) | FLISTP_QH;
const u32 def_ptr = virt_to_phys(uhcic->qh_prei) | FLISTP_QH;
int i;
for (i = 0; i < 1024; ++i) {
if (uhcic->framelistptr[i] == qh_ptr)
uhcic->framelistptr[i] = def_ptr;
}
free(q->data);
free(q->tds);
free(q->qh);
free(q);
}
/* read one intr-packet from queue, if available. extend the queue for new input.
return NULL if nothing new available.
Recommended use: while (data=poll_intr_queue(q)) process(data);
*/
static u8*
uhci_poll_intr_queue (void *q_)
{
intr_q *q = (intr_q*)q_;
if ((q->tds[q->lastread].ctrlsts & TD_STATUS_ACTIVE) == 0) {
int current = q->lastread;
int previous;
if (q->lastread == 0) {
previous = q->total - 1;
} else {
previous = q->lastread - 1;
}
q->tds[previous].ctrlsts &= ~TD_STATUS_MASK;
q->tds[previous].ptr = 0 | TD_TERMINATE;
if (q->last_td != &q->tds[previous]) {
q->last_td->ptr = virt_to_phys(&q->tds[previous]) & ~TD_TERMINATE;
q->last_td = &q->tds[previous];
}
q->tds[previous].ctrlsts |= TD_STATUS_ACTIVE;
q->lastread = (q->lastread + 1) % q->total;
if (!(q->tds[current].ctrlsts & TD_STATUS_MASK))
return &q->data[current*q->reqsize];
}
/* reset queue if we fully processed it after underrun */
else if (q->qh->elementlinkptr & FLISTP_TERMINATE) {
usb_debug("resetting underrun uhci interrupt queue.\n");
q->qh->elementlinkptr = virt_to_phys(q->tds + q->lastread);
}
return NULL;
}
void
uhci_reg_write32 (hci_t *ctrl, usbreg reg, u32 value)
{
outl (value, ctrl->reg_base + reg);
}
u32
uhci_reg_read32 (hci_t *ctrl, usbreg reg)
{
return inl (ctrl->reg_base + reg);
}
void
uhci_reg_write16 (hci_t *ctrl, usbreg reg, u16 value)
{
outw (value, ctrl->reg_base + reg);
}
u16
uhci_reg_read16 (hci_t *ctrl, usbreg reg)
{
return inw (ctrl->reg_base + reg);
}
void
uhci_reg_write8 (hci_t *ctrl, usbreg reg, u8 value)
{
outb (value, ctrl->reg_base + reg);
}
u8
uhci_reg_read8 (hci_t *ctrl, usbreg reg)
{
return inb (ctrl->reg_base + reg);
}