source: mainline/uspace/drv/bus/usb/ohci/hc.c@ fc6e607

/*
 * Copyright (c) 2011 Jan Vesely
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - 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.
 * - 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 ``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 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.
 */
/** @addtogroup drvusbohcihc
 * @{
 */
/** @file
 * @brief OHCI Host controller driver routines
 */
#include <errno.h>
#include <str_error.h>
#include <adt/list.h>
#include <libarch/ddi.h>

#include <usb/debug.h>
#include <usb/usb.h>
#include <usb/ddfiface.h>

#include "hc.h"
#include "hcd_endpoint.h"

#define OHCI_USED_INTERRUPTS \
    (I_SO | I_WDH | I_UE | I_RHSC)

static const irq_cmd_t ohci_irq_commands[] =
{
        { .cmd = CMD_MEM_READ_32, .dstarg = 1, .addr = NULL /*filled later*/ },
        { .cmd = CMD_BTEST, .srcarg = 1, .dstarg = 2, .value = OHCI_USED_INTERRUPTS },
        { .cmd = CMD_PREDICATE, .srcarg = 2, .value = 2 },
        { .cmd = CMD_MEM_WRITE_A_32, .srcarg = 1, .addr = NULL /*filled later*/ },
        { .cmd = CMD_ACCEPT },
};

static void hc_gain_control(hc_t *instance);
static void hc_start(hc_t *instance);
static int hc_init_transfer_lists(hc_t *instance);
static int hc_init_memory(hc_t *instance);
static int interrupt_emulator(hc_t *instance);

/*----------------------------------------------------------------------------*/
/** Get number of commands used in IRQ code.
 * @return Number of commands.
 */
size_t hc_irq_cmd_count(void)
{
        return sizeof(ohci_irq_commands) / sizeof(irq_cmd_t);
}
/*----------------------------------------------------------------------------*/
/** Generate IRQ code commands.
 * @param[out] cmds Place to store the commands.
 * @param[in] cmd_size Size of the place (bytes).
 * @param[in] regs Physical address of device's registers.
 * @param[in] reg_size Size of the register area (bytes).
 *
 * @return Error code.
 */
int hc_get_irq_commands(
    irq_cmd_t cmds[], size_t cmd_size, uintptr_t regs, size_t reg_size)
{
        if (cmd_size < sizeof(ohci_irq_commands)
            || reg_size < sizeof(ohci_regs_t))
                return EOVERFLOW;

        /* Create register mapping to use in IRQ handler.
         * This mapping should be present in kernel only.
         * Remove it from here when kernel knows how to create mappings
         * and accepts physical addresses in IRQ code.
         * TODO: remove */
        ohci_regs_t *registers;
        const int ret = pio_enable((void*)regs, reg_size, (void**)&registers);

        /* Some bogus access to force create mapping. DO NOT remove,
         * unless whole virtual addresses in irq is replaced
         * NOTE: Compiler won't remove this as ohci_regs_t members
         * are declared volatile. */
        registers->revision;

        if (ret != EOK)
                return ret;

        memcpy(cmds, ohci_irq_commands, sizeof(ohci_irq_commands));

        void *address = (void*)&registers->interrupt_status;
        cmds[0].addr = address;
        cmds[3].addr = address;
        return EOK;
}
/*----------------------------------------------------------------------------*/
/** Announce OHCI root hub to the DDF
 *
 * @param[in] instance OHCI driver intance
 * @param[in] hub_fun DDF fuction representing OHCI root hub
 * @return Error code
 */
int hc_register_hub(hc_t *instance, ddf_fun_t *hub_fun)
{
        assert(instance);
        assert(hub_fun);

        const usb_address_t hub_address =
            device_keeper_get_free_address(&instance->manager, USB_SPEED_FULL);
        if (hub_address <= 0) {
                usb_log_error("Failed to get OHCI root hub address: %s\n",
                    str_error(hub_address));
                return hub_address;
        }
        instance->rh.address = hub_address;
        usb_device_keeper_bind(
            &instance->manager, hub_address, hub_fun->handle);

#define CHECK_RET_RELEASE(ret, message...) \
if (ret != EOK) { \
        usb_log_error(message); \
        hc_remove_endpoint(instance, hub_address, 0, USB_DIRECTION_BOTH); \
        usb_device_keeper_release(&instance->manager, hub_address); \
        return ret; \
} else (void)0

        int ret = hc_add_endpoint(instance, hub_address, 0, USB_SPEED_FULL,
            USB_TRANSFER_CONTROL, USB_DIRECTION_BOTH, 64, 0, 0);
        CHECK_RET_RELEASE(ret,
            "Failed to add OHCI root hub endpoint 0: %s.\n", str_error(ret));

        char *match_str = NULL;
        /* DDF needs heap allocated string. */
        ret = asprintf(&match_str, "usb&class=hub");
        ret = ret > 0 ? 0 : ret;
        CHECK_RET_RELEASE(ret,
            "Failed to create match-id string: %s.\n", str_error(ret));

        ret = ddf_fun_add_match_id(hub_fun, match_str, 100);
        CHECK_RET_RELEASE(ret,
            "Failed to add root hub match-id: %s.\n", str_error(ret));

        ret = ddf_fun_bind(hub_fun);
        CHECK_RET_RELEASE(ret,
            "Failed to bind root hub function: %s.\n", str_error(ret));

        return EOK;
#undef CHECK_RET_RELEASE
}
/*----------------------------------------------------------------------------*/
/** Initialize OHCI hc driver structure
 *
 * @param[in] instance Memory place for the structure.
 * @param[in] regs Address of the memory mapped I/O registers.
 * @param[in] reg_size Size of the memory mapped area.
 * @param[in] interrupts True if w interrupts should be used
 * @return Error code
 */
int hc_init(hc_t *instance, uintptr_t regs, size_t reg_size, bool interrupts)
{
        assert(instance);

#define CHECK_RET_RETURN(ret, message...) \
if (ret != EOK) { \
        usb_log_error(message); \
        return ret; \
} else (void)0

        int ret =
            pio_enable((void*)regs, reg_size, (void**)&instance->registers);
        CHECK_RET_RETURN(ret,
            "Failed to gain access to device registers: %s.\n", str_error(ret));

        list_initialize(&instance->pending_batches);
        usb_device_keeper_init(&instance->manager);

        ret = usb_endpoint_manager_init(&instance->ep_manager,
            BANDWIDTH_AVAILABLE_USB11);
        CHECK_RET_RETURN(ret, "Failed to initialize endpoint manager: %s.\n",
            str_error(ret));

        ret = hc_init_memory(instance);
        CHECK_RET_RETURN(ret, "Failed to create OHCI memory structures: %s.\n",
            str_error(ret));
#undef CHECK_RET_RETURN

        fibril_mutex_initialize(&instance->guard);

        hc_gain_control(instance);

        if (!interrupts) {
                instance->interrupt_emulator =
                    fibril_create((int(*)(void*))interrupt_emulator, instance);
                fibril_add_ready(instance->interrupt_emulator);
        }

        rh_init(&instance->rh, instance->registers);
        hc_start(instance);

        return EOK;
}
/*----------------------------------------------------------------------------*/
/** Create and register endpoint structures.
 *
 * @param[in] instance OHCI driver structure.
 * @param[in] address USB address of the device.
 * @param[in] endpoint USB endpoint number.
 * @param[in] speed Communication speeed of the device.
 * @param[in] type Endpoint's transfer type.
 * @param[in] direction Endpoint's direction.
 * @param[in] mps Maximum packet size the endpoint accepts.
 * @param[in] size Maximum allowed buffer size.
 * @param[in] interval Time between transfers(interrupt transfers only).
 * @return Error code
 */
int hc_add_endpoint(
    hc_t *instance, usb_address_t address, usb_endpoint_t endpoint,
    usb_speed_t speed, usb_transfer_type_t type, usb_direction_t direction,
    size_t mps, size_t size, unsigned interval)
{
        endpoint_t *ep =
            endpoint_get(address, endpoint, direction, type, speed, mps);
        if (ep == NULL)
                return ENOMEM;

        hcd_endpoint_t *hcd_ep = hcd_endpoint_assign(ep);
        if (hcd_ep == NULL) {
                endpoint_destroy(ep);
                return ENOMEM;
        }

        int ret =
            usb_endpoint_manager_register_ep(&instance->ep_manager, ep, size);
        if (ret != EOK) {
                hcd_endpoint_clear(ep);
                endpoint_destroy(ep);
                return ret;
        }

        /* Enqueue hcd_ep */
        switch (ep->transfer_type) {
        case USB_TRANSFER_CONTROL:
                instance->registers->control &= ~C_CLE;
                endpoint_list_add_ep(
                    &instance->lists[ep->transfer_type], hcd_ep);
                instance->registers->control_current = 0;
                instance->registers->control |= C_CLE;
                break;
        case USB_TRANSFER_BULK:
                instance->registers->control &= ~C_BLE;
                endpoint_list_add_ep(
                    &instance->lists[ep->transfer_type], hcd_ep);
                instance->registers->control |= C_BLE;
                break;
        case USB_TRANSFER_ISOCHRONOUS:
        case USB_TRANSFER_INTERRUPT:
                instance->registers->control &= (~C_PLE & ~C_IE);
                endpoint_list_add_ep(
                    &instance->lists[ep->transfer_type], hcd_ep);
                instance->registers->control |= C_PLE | C_IE;
                break;
        }

        return EOK;
}
/*----------------------------------------------------------------------------*/
/** Dequeue and delete endpoint structures
 *
 * @param[in] instance OHCI hc driver structure.
 * @param[in] address USB address of the device.
 * @param[in] endpoint USB endpoint number.
 * @param[in] direction Direction of the endpoint.
 * @return Error code
 */
int hc_remove_endpoint(hc_t *instance, usb_address_t address,
    usb_endpoint_t endpoint, usb_direction_t direction)
{
        assert(instance);
        fibril_mutex_lock(&instance->guard);
        endpoint_t *ep = usb_endpoint_manager_get_ep(&instance->ep_manager,
            address, endpoint, direction, NULL);
        if (ep == NULL) {
                usb_log_error("Endpoint unregister failed: No such EP.\n");
                fibril_mutex_unlock(&instance->guard);
                return ENOENT;
        }

        hcd_endpoint_t *hcd_ep = hcd_endpoint_get(ep);
        if (hcd_ep) {
                /* Dequeue hcd_ep */
                switch (ep->transfer_type) {
                case USB_TRANSFER_CONTROL:
                        instance->registers->control &= ~C_CLE;
                        endpoint_list_remove_ep(
                            &instance->lists[ep->transfer_type], hcd_ep);
                        instance->registers->control_current = 0;
                        instance->registers->control |= C_CLE;
                        break;
                case USB_TRANSFER_BULK:
                        instance->registers->control &= ~C_BLE;
                        endpoint_list_remove_ep(
                            &instance->lists[ep->transfer_type], hcd_ep);
                        instance->registers->control |= C_BLE;
                        break;
                case USB_TRANSFER_ISOCHRONOUS:
                case USB_TRANSFER_INTERRUPT:
                        instance->registers->control &= (~C_PLE & ~C_IE);
                        endpoint_list_remove_ep(
                            &instance->lists[ep->transfer_type], hcd_ep);
                        instance->registers->control |= C_PLE | C_IE;
                        break;
                default:
                        break;
                }
                hcd_endpoint_clear(ep);
        } else {
                usb_log_warning("Endpoint without hcd equivalent structure.\n");
        }
        int ret = usb_endpoint_manager_unregister_ep(&instance->ep_manager,
            address, endpoint, direction);
        fibril_mutex_unlock(&instance->guard);
        return ret;
}
/*----------------------------------------------------------------------------*/
/** Get access to endpoint structures
 *
 * @param[in] instance OHCI hc driver structure.
 * @param[in] address USB address of the device.
 * @param[in] endpoint USB endpoint number.
 * @param[in] direction Direction of the endpoint.
 * @param[out] bw Reserved bandwidth.
 * @return Error code
 */
endpoint_t * hc_get_endpoint(hc_t *instance, usb_address_t address,
    usb_endpoint_t endpoint, usb_direction_t direction, size_t *bw)
{
        assert(instance);
        fibril_mutex_lock(&instance->guard);
        endpoint_t *ep = usb_endpoint_manager_get_ep(&instance->ep_manager,
            address, endpoint, direction, bw);
        fibril_mutex_unlock(&instance->guard);
        return ep;
}
/*----------------------------------------------------------------------------*/
/** Add USB transfer to the schedule.
 *
 * @param[in] instance OHCI hc driver structure.
 * @param[in] batch Batch representing the transfer.
 * @return Error code.
 */
int hc_schedule(hc_t *instance, usb_transfer_batch_t *batch)
{
        assert(instance);
        assert(batch);
        assert(batch->ep);

        /* Check for root hub communication */
        if (batch->ep->address == instance->rh.address) {
                rh_request(&instance->rh, batch);
                return EOK;
        }

        fibril_mutex_lock(&instance->guard);
        list_append(&batch->link, &instance->pending_batches);
        batch_commit(batch);

        /* Control and bulk schedules need a kick to start working */
        switch (batch->ep->transfer_type)
        {
        case USB_TRANSFER_CONTROL:
                instance->registers->command_status |= CS_CLF;
                break;
        case USB_TRANSFER_BULK:
                instance->registers->command_status |= CS_BLF;
                break;
        default:
                break;
        }
        fibril_mutex_unlock(&instance->guard);
        return EOK;
}
/*----------------------------------------------------------------------------*/
/** Interrupt handling routine
 *
 * @param[in] instance OHCI hc driver structure.
 * @param[in] status Value of the status register at the time of interrupt.
 */
void hc_interrupt(hc_t *instance, uint32_t status)
{
        assert(instance);
        if ((status & ~I_SF) == 0) /* ignore sof status */
                return;
        usb_log_debug2("OHCI(%p) interrupt: %x.\n", instance, status);
        if (status & I_RHSC)
                rh_interrupt(&instance->rh);

        if (status & I_WDH) {
                fibril_mutex_lock(&instance->guard);
                usb_log_debug2("HCCA: %p-%#" PRIx32 " (%p).\n", instance->hcca,
                    instance->registers->hcca,
                    (void *) addr_to_phys(instance->hcca));
                usb_log_debug2("Periodic current: %#" PRIx32 ".\n",
                    instance->registers->periodic_current);

                link_t *current = instance->pending_batches.head.next;
                while (current != &instance->pending_batches.head) {
                        link_t *next = current->next;
                        usb_transfer_batch_t *batch =
                            usb_transfer_batch_from_link(current);

                        if (batch_is_complete(batch)) {
                                list_remove(current);
                                usb_transfer_batch_finish(batch);
                        }

                        current = next;
                }
                fibril_mutex_unlock(&instance->guard);
        }

        if (status & I_UE) {
                hc_start(instance);
        }

}
/*----------------------------------------------------------------------------*/
/** Check status register regularly
 *
 * @param[in] instance OHCI hc driver structure.
 * @return Error code
 */
int interrupt_emulator(hc_t *instance)
{
        assert(instance);
        usb_log_info("Started interrupt emulator.\n");
        while (1) {
                const uint32_t status = instance->registers->interrupt_status;
                instance->registers->interrupt_status = status;
                hc_interrupt(instance, status);
                async_usleep(10000);
        }
        return EOK;
}
/*----------------------------------------------------------------------------*/
/** Turn off any (BIOS)driver that might be in control of the device.
 *
 * This function implements routines described in chapter 5.1.1.3 of the OHCI
 * specification (page 40, pdf page 54).
 *
 * @param[in] instance OHCI hc driver structure.
 */
void hc_gain_control(hc_t *instance)
{
        assert(instance);

        usb_log_debug("Requesting OHCI control.\n");
        if (instance->registers->revision & R_LEGACY_FLAG) {
                /* Turn off legacy emulation, it should be enough to zero
                 * the lowest bit, but it caused problems. Thus clear all
                 * except GateA20 (causes restart on some hw).
                 * See page 145 of the specs for details.
                 */
                volatile uint32_t *ohci_emulation_reg =
                (uint32_t*)((char*)instance->registers + LEGACY_REGS_OFFSET);
                usb_log_debug("OHCI legacy register %p: %x.\n",
                    ohci_emulation_reg, *ohci_emulation_reg);
                /* Zero everything but A20State */
                *ohci_emulation_reg &= 0x100;
                usb_log_debug(
                    "OHCI legacy register (should be 0 or 0x100) %p: %x.\n",
                    ohci_emulation_reg, *ohci_emulation_reg);
        }

        /* Interrupt routing enabled => smm driver is active */
        if (instance->registers->control & C_IR) {
                usb_log_debug("SMM driver: request ownership change.\n");
                instance->registers->command_status |= CS_OCR;
                /* Hope that SMM actually knows its stuff or we can hang here */
                while (instance->registers->control & C_IR) {
                        async_usleep(1000);
                }
                usb_log_info("SMM driver: Ownership taken.\n");
                C_HCFS_SET(instance->registers->control, C_HCFS_RESET);
                async_usleep(50000);
                return;
        }

        const unsigned hc_status = C_HCFS_GET(instance->registers->control);
        /* Interrupt routing disabled && status != USB_RESET => BIOS active */
        if (hc_status != C_HCFS_RESET) {
                usb_log_debug("BIOS driver found.\n");
                if (hc_status == C_HCFS_OPERATIONAL) {
                        usb_log_info("BIOS driver: HC operational.\n");
                        return;
                }
                /* HC is suspended assert resume for 20ms, */
                C_HCFS_SET(instance->registers->control, C_HCFS_RESUME);
                async_usleep(20000);
                usb_log_info("BIOS driver: HC resumed.\n");
                return;
        }

        /* HC is in reset (hw startup) => no other driver
         * maintain reset for at least the time specified in USB spec (50 ms)*/
        usb_log_debug("Host controller found in reset state.\n");
        async_usleep(50000);
}
/*----------------------------------------------------------------------------*/
/** OHCI hw initialization routine.
 *
 * @param[in] instance OHCI hc driver structure.
 */
void hc_start(hc_t *instance)
{
        /* OHCI guide page 42 */
        assert(instance);
        usb_log_debug2("Started hc initialization routine.\n");

        /* Save contents of fm_interval register */
        const uint32_t fm_interval = instance->registers->fm_interval;
        usb_log_debug2("Old value of HcFmInterval: %x.\n", fm_interval);

        /* Reset hc */
        usb_log_debug2("HC reset.\n");
        size_t time = 0;
        instance->registers->command_status = CS_HCR;
        while (instance->registers->command_status & CS_HCR) {
                async_usleep(10);
                time += 10;
        }
        usb_log_debug2("HC reset complete in %zu us.\n", time);

        /* Restore fm_interval */
        instance->registers->fm_interval = fm_interval;
        assert((instance->registers->command_status & CS_HCR) == 0);

        /* hc is now in suspend state */
        usb_log_debug2("HC should be in suspend state(%x).\n",
            instance->registers->control);

        /* Use HCCA */
        instance->registers->hcca = addr_to_phys(instance->hcca);

        /* Use queues */
        instance->registers->bulk_head =
            instance->lists[USB_TRANSFER_BULK].list_head_pa;
        usb_log_debug2("Bulk HEAD set to: %p (%#" PRIx32 ").\n",
            instance->lists[USB_TRANSFER_BULK].list_head,
            instance->lists[USB_TRANSFER_BULK].list_head_pa);

        instance->registers->control_head =
            instance->lists[USB_TRANSFER_CONTROL].list_head_pa;
        usb_log_debug2("Control HEAD set to: %p (%#" PRIx32 ").\n",
            instance->lists[USB_TRANSFER_CONTROL].list_head,
            instance->lists[USB_TRANSFER_CONTROL].list_head_pa);

        /* Enable queues */
        instance->registers->control |= (C_PLE | C_IE | C_CLE | C_BLE);
        usb_log_debug2("All queues enabled(%x).\n",
            instance->registers->control);

        /* Enable interrupts */
        instance->registers->interrupt_enable = OHCI_USED_INTERRUPTS;
        usb_log_debug2("Enabled interrupts: %x.\n",
            instance->registers->interrupt_enable);
        instance->registers->interrupt_enable = I_MI;

        /* Set periodic start to 90% */
        uint32_t frame_length = ((fm_interval >> FMI_FI_SHIFT) & FMI_FI_MASK);
        instance->registers->periodic_start = (frame_length / 10) * 9;
        usb_log_debug2("All periodic start set to: %x(%u - 90%% of %d).\n",
            instance->registers->periodic_start,
            instance->registers->periodic_start, frame_length);

        C_HCFS_SET(instance->registers->control, C_HCFS_OPERATIONAL);
        usb_log_debug("OHCI HC up and running (ctl_reg=0x%x).\n",
            instance->registers->control);
}
/*----------------------------------------------------------------------------*/
/** Initialize schedule queues
 *
 * @param[in] instance OHCI hc driver structure
 * @return Error code
 */
int hc_init_transfer_lists(hc_t *instance)
{
        assert(instance);
#define SETUP_ENDPOINT_LIST(type) \
do { \
        const char *name = usb_str_transfer_type(type); \
        int ret = endpoint_list_init(&instance->lists[type], name); \
        if (ret != EOK) { \
                usb_log_error("Failed to setup %s endpoint list: %s.\n", \
                    name, str_error(ret)); \
                endpoint_list_fini(&instance->lists[USB_TRANSFER_ISOCHRONOUS]);\
                endpoint_list_fini(&instance->lists[USB_TRANSFER_INTERRUPT]); \
                endpoint_list_fini(&instance->lists[USB_TRANSFER_CONTROL]); \
                endpoint_list_fini(&instance->lists[USB_TRANSFER_BULK]); \
                return ret; \
        } \
} while (0)

        SETUP_ENDPOINT_LIST(USB_TRANSFER_ISOCHRONOUS);
        SETUP_ENDPOINT_LIST(USB_TRANSFER_INTERRUPT);
        SETUP_ENDPOINT_LIST(USB_TRANSFER_CONTROL);
        SETUP_ENDPOINT_LIST(USB_TRANSFER_BULK);
#undef SETUP_ENDPOINT_LIST
        endpoint_list_set_next(&instance->lists[USB_TRANSFER_INTERRUPT],
            &instance->lists[USB_TRANSFER_ISOCHRONOUS]);

        return EOK;
}
/*----------------------------------------------------------------------------*/
/** Initialize memory structures used by the OHCI hcd.
 *
 * @param[in] instance OHCI hc driver structure.
 * @return Error code.
 */
int hc_init_memory(hc_t *instance)
{
        assert(instance);

        bzero(&instance->rh, sizeof(instance->rh));
        /* Init queues */
        const int ret = hc_init_transfer_lists(instance);
        if (ret != EOK) {
                return ret;
        }

        /*Init HCCA */
        instance->hcca = malloc32(sizeof(hcca_t));
        if (instance->hcca == NULL)
                return ENOMEM;
        bzero(instance->hcca, sizeof(hcca_t));
        usb_log_debug2("OHCI HCCA initialized at %p.\n", instance->hcca);

        unsigned i = 0;
        for (; i < 32; ++i) {
                instance->hcca->int_ep[i] =
                    instance->lists[USB_TRANSFER_INTERRUPT].list_head_pa;
        }
        usb_log_debug2("Interrupt HEADs set to: %p (%#" PRIx32 ").\n",
            instance->lists[USB_TRANSFER_INTERRUPT].list_head,
            instance->lists[USB_TRANSFER_INTERRUPT].list_head_pa);

        return EOK;
}

/**
 * @}
 */