xref: /freebsd-10.1-release/sys/contrib/octeon-sdk/cvmx-usb.c

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/**
 * @file
 *
 * "cvmx-usb.c" defines a set of low level USB functions to help
 * developers create Octeon USB drivers for various operating
 * systems. These functions provide a generic API to the Octeon
 * USB blocks, hiding the internal hardware specific
 * operations.
 *
 * <hr>$Revision: 32636 $<hr>
 */
#include "cvmx.h"
#include "cvmx-sysinfo.h"
#include "cvmx-usb.h"
#include "cvmx-helper.h"
#include "cvmx-helper-board.h"
#include "cvmx-csr-db.h"
#include "cvmx-swap.h"

#define MAX_RETRIES         3   /* Maximum number of times to retry failed transactions */
#define MAX_PIPES           32  /* Maximum number of pipes that can be open at once */
#define MAX_TRANSACTIONS    256 /* Maximum number of outstanding transactions across all pipes */
#define MAX_CHANNELS        8   /* Maximum number of hardware channels supported by the USB block */
#define MAX_USB_ADDRESS     127 /* The highest valid USB device address */
#define MAX_USB_ENDPOINT    15  /* The highest valid USB endpoint number */
#define MAX_USB_HUB_PORT    15  /* The highest valid port number on a hub */
#define ALLOW_CSR_DECODES   0   /* CSR decoding when CVMX_USB_INITIALIZE_FLAGS_DEBUG_CSRS is set
                                    enlarges the code a lot. This define overrides the ability to do CSR
                                    decoding since it isn't necessary 99% of the time. Change this to a
                                    one if you need CSR decoding */

/* These defines disable the normal read and write csr. This is so I can add
    extra debug stuff to the usb specific version and I won't use the normal
    version by mistake */
#define cvmx_read_csr use_cvmx_usb_read_csr64_instead_of_cvmx_read_csr
#define cvmx_write_csr use_cvmx_usb_write_csr64_instead_of_cvmx_write_csr

typedef enum
{
    __CVMX_USB_TRANSACTION_FLAGS_IN_USE = 1<<16,
} cvmx_usb_transaction_flags_t;

/**
 * Logical transactions may take numerous low level
 * transactions, especially when splits are concerned. This
 * enum represents all of the possible stages a transaction can
 * be in. Note that split completes are always even. This is so
 * the NAK handler can backup to the previous low level
 * transaction with a simple clearing of bit 0.
 */
typedef enum
{
    CVMX_USB_STAGE_NON_CONTROL,
    CVMX_USB_STAGE_NON_CONTROL_SPLIT_COMPLETE,
    CVMX_USB_STAGE_SETUP,
    CVMX_USB_STAGE_SETUP_SPLIT_COMPLETE,
    CVMX_USB_STAGE_DATA,
    CVMX_USB_STAGE_DATA_SPLIT_COMPLETE,
    CVMX_USB_STAGE_STATUS,
    CVMX_USB_STAGE_STATUS_SPLIT_COMPLETE,
} cvmx_usb_stage_t;

/**
 * This structure describes each pending USB transaction
 * regardless of type. These are linked together to form a list
 * of pending requests for a pipe.
 */
typedef struct cvmx_usb_transaction
{
    struct cvmx_usb_transaction *prev;  /**< Transaction before this one in the pipe */
    struct cvmx_usb_transaction *next;  /**< Transaction after this one in the pipe */
    cvmx_usb_transfer_t type;           /**< Type of transaction, duplicated of the pipe */
    cvmx_usb_transaction_flags_t flags; /**< State flags for this transaction */
    uint64_t buffer;                    /**< User's physical buffer address to read/write */
    int buffer_length;                  /**< Size of the user's buffer in bytes */
    uint64_t control_header;            /**< For control transactions, physical address of the 8 byte standard header */
    int iso_start_frame;                /**< For ISO transactions, the starting frame number */
    int iso_number_packets;             /**< For ISO transactions, the number of packets in the request */
    cvmx_usb_iso_packet_t *iso_packets; /**< For ISO transactions, the sub packets in the request */
    int xfersize;
    int pktcnt;
    int retries;
    int actual_bytes;                   /**< Actual bytes transfer for this transaction */
    cvmx_usb_stage_t stage;             /**< For control transactions, the current stage */
    cvmx_usb_callback_func_t callback;  /**< User's callback function when complete */
    void *callback_data;                /**< User's data */
} cvmx_usb_transaction_t;

/**
 * A pipe represents a virtual connection between Octeon and some
 * USB device. It contains a list of pending request to the device.
 */
typedef struct cvmx_usb_pipe
{
    struct cvmx_usb_pipe *prev;         /**< Pipe before this one in the list */
    struct cvmx_usb_pipe *next;         /**< Pipe after this one in the list */
    cvmx_usb_transaction_t *head;       /**< The first pending transaction */
    cvmx_usb_transaction_t *tail;       /**< The last pending transaction */
    uint64_t interval;                  /**< For periodic pipes, the interval between packets in cycles */
    uint64_t next_tx_cycle;             /**< The next cycle this pipe is allowed to transmit on */
    cvmx_usb_pipe_flags_t flags;        /**< State flags for this pipe */
    cvmx_usb_speed_t device_speed;      /**< Speed of device connected to this pipe */
    cvmx_usb_transfer_t transfer_type;  /**< Type of transaction supported by this pipe */
    cvmx_usb_direction_t transfer_dir;  /**< IN or OUT. Ignored for Control */
    int multi_count;                    /**< Max packet in a row for the device */
    uint16_t max_packet;                /**< The device's maximum packet size in bytes */
    uint8_t device_addr;                /**< USB device address at other end of pipe */
    uint8_t endpoint_num;               /**< USB endpoint number at other end of pipe */
    uint8_t hub_device_addr;            /**< Hub address this device is connected to */
    uint8_t hub_port;                   /**< Hub port this device is connected to */
    uint8_t pid_toggle;                 /**< This toggles between 0/1 on every packet send to track the data pid needed */
    uint8_t channel;                    /**< Hardware DMA channel for this pipe */
    int8_t  split_sc_frame;             /**< The low order bits of the frame number the split complete should be sent on */
} cvmx_usb_pipe_t;

typedef struct
{
    cvmx_usb_pipe_t *head;              /**< Head of the list, or NULL if empty */
    cvmx_usb_pipe_t *tail;              /**< Tail if the list, or NULL if empty */
} cvmx_usb_pipe_list_t;

/**
 * The state of the USB block is stored in this structure
 */
typedef struct
{
    int init_flags;                     /**< Flags passed to initialize */
    int index;                          /**< Which USB block this is for */
    int idle_hardware_channels;         /**< Bit set for every idle hardware channel */
    int active_transactions;            /**< Number of active transactions across all pipes */
    cvmx_usbcx_hprt_t usbcx_hprt;       /**< Stored port status so we don't need to read a CSR to determine splits */
    cvmx_usb_pipe_t *pipe_for_channel[MAX_CHANNELS];    /**< Map channels to pipes */
    cvmx_usb_transaction_t *free_transaction_head;      /**< List of free transactions head */
    cvmx_usb_transaction_t *free_transaction_tail;      /**< List of free transactions tail */
    cvmx_usb_pipe_t pipe[MAX_PIPES];                    /**< Storage for pipes */
    cvmx_usb_transaction_t transaction[MAX_TRANSACTIONS];       /**< Storage for transactions */
    cvmx_usb_callback_func_t callback[__CVMX_USB_CALLBACK_END]; /**< User global callbacks */
    void *callback_data[__CVMX_USB_CALLBACK_END];               /**< User data for each callback */
    int indent;                         /**< Used by debug output to indent functions */
    cvmx_usb_port_status_t port_status; /**< Last port status used for change notification */
    cvmx_usb_pipe_list_t free_pipes;    /**< List of all pipes that are currently closed */
    cvmx_usb_pipe_list_t idle_pipes;    /**< List of open pipes that have no transactions */
    cvmx_usb_pipe_list_t active_pipes[4]; /**< Active pipes indexed by transfer type */
} cvmx_usb_internal_state_t;

/* This macro logs out whenever a function is called if debugging is on */
#define CVMX_USB_LOG_CALLED() \
    if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEBUG_CALLS)) \
        cvmx_dprintf("%*s%s: called\n", 2*usb->indent++, "", __FUNCTION__);

/* This macro logs out each function parameter if debugging is on */
#define CVMX_USB_LOG_PARAM(format, param) \
    if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEBUG_CALLS)) \
        cvmx_dprintf("%*s%s: param %s = " format "\n", 2*usb->indent, "", __FUNCTION__, #param, param);

/* This macro logs out when a function returns a value */
#define CVMX_USB_RETURN(v)                                              \
    do {                                                                \
        __typeof(v) r = v;                                              \
        if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEBUG_CALLS))    \
            cvmx_dprintf("%*s%s: returned %s(%d)\n", 2*--usb->indent, "", __FUNCTION__, #v, r); \
        return r;                                                       \
    } while (0);

/* This macro logs out when a function doesn't return a value */
#define CVMX_USB_RETURN_NOTHING()                                       \
    do {                                                                \
        if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEBUG_CALLS))    \
            cvmx_dprintf("%*s%s: returned\n", 2*--usb->indent, "", __FUNCTION__); \
        return;                                                         \
    } while (0);

/* This macro spins on a field waiting for it to reach a value */
#define CVMX_WAIT_FOR_FIELD32(address, type, field, op, value, timeout_usec)\
    ({int result;                                                       \
    do {                                                                \
        uint64_t done = cvmx_get_cycle() + (uint64_t)timeout_usec *     \
                           cvmx_sysinfo_get()->cpu_clock_hz / 1000000;  \
        type c;                                                         \
        while (1)                                                       \
        {                                                               \
            c.u32 = __cvmx_usb_read_csr32(usb, address);                \
            if (c.s.field op (value)) {                                 \
                result = 0;                                             \
                break;                                                  \
            } else if (cvmx_get_cycle() > done) {                       \
                result = -1;                                            \
                break;                                                  \
            } else                                                      \
                cvmx_wait(100);                                         \
        }                                                               \
    } while (0);                                                        \
    result;})

/* This macro logically sets a single field in a CSR. It does the sequence
    read, modify, and write */
#define USB_SET_FIELD32(address, type, field, value)\
    do {                                            \
        type c;                                     \
        c.u32 = __cvmx_usb_read_csr32(usb, address);\
        c.s.field = value;                          \
        __cvmx_usb_write_csr32(usb, address, c.u32);\
    } while (0)


/**
 * @INTERNAL
 * Read a USB 32bit CSR. It performs the necessary address swizzle
 * for 32bit CSRs and logs the value in a readable format if
 * debugging is on.
 *
 * @param usb     USB block this access is for
 * @param address 64bit address to read
 *
 * @return Result of the read
 */
static inline uint32_t __cvmx_usb_read_csr32(cvmx_usb_internal_state_t *usb,
                                             uint64_t address)
{
    uint32_t result = cvmx_read64_uint32(address ^ 4);
#if ALLOW_CSR_DECODES
    if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEBUG_CSRS))
    {
        cvmx_dprintf("Read: ");
        cvmx_csr_db_decode(cvmx_get_proc_id(), address, result);
    }
#endif
    return result;
}


/**
 * @INTERNAL
 * Write a USB 32bit CSR. It performs the necessary address
 * swizzle for 32bit CSRs and logs the value in a readable format
 * if debugging is on.
 *
 * @param usb     USB block this access is for
 * @param address 64bit address to write
 * @param value   Value to write
 */
static inline void __cvmx_usb_write_csr32(cvmx_usb_internal_state_t *usb,
                                          uint64_t address, uint32_t value)
{
#if ALLOW_CSR_DECODES
    if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEBUG_CSRS))
    {
        cvmx_dprintf("Write: ");
        cvmx_csr_db_decode(cvmx_get_proc_id(), address, value);
    }
#endif
    cvmx_write64_uint32(address ^ 4, value);
}


/**
 * @INTERNAL
 * Read a USB 64bit CSR. It logs the value in a readable format if
 * debugging is on.
 *
 * @param usb     USB block this access is for
 * @param address 64bit address to read
 *
 * @return Result of the read
 */
static inline uint64_t __cvmx_usb_read_csr64(cvmx_usb_internal_state_t *usb,
                                             uint64_t address)
{
    uint64_t result = cvmx_read64_uint64(address);
#if ALLOW_CSR_DECODES
    if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEBUG_CSRS))
    {
        cvmx_dprintf("Read: ");
        cvmx_csr_db_decode(cvmx_get_proc_id(), address, result);
    }
#endif
    return result;
}


/**
 * @INTERNAL
 * Write a USB 64bit CSR. It logs the value in a readable format
 * if debugging is on.
 *
 * @param usb     USB block this access is for
 * @param address 64bit address to write
 * @param value   Value to write
 */
static inline void __cvmx_usb_write_csr64(cvmx_usb_internal_state_t *usb,
                                          uint64_t address, uint64_t value)
{
#if ALLOW_CSR_DECODES
    if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEBUG_CSRS))
    {
        cvmx_dprintf("Write: ");
        cvmx_csr_db_decode(cvmx_get_proc_id(), address, value);
    }
#endif
    cvmx_write64_uint64(address, value);
}


/**
 * @INTERNAL
 * Uitility function to convert complete codes into strings
 *
 * @param complete_code
 *               Code to convert
 *
 * @return Human readable string
 */
static const char *__cvmx_usb_complete_to_string(cvmx_usb_complete_t complete_code)
{
    switch (complete_code)
    {
        case CVMX_USB_COMPLETE_SUCCESS: return "SUCCESS";
        case CVMX_USB_COMPLETE_SHORT:   return "SHORT";
        case CVMX_USB_COMPLETE_CANCEL:  return "CANCEL";
        case CVMX_USB_COMPLETE_ERROR:   return "ERROR";
        case CVMX_USB_COMPLETE_STALL:   return "STALL";
        case CVMX_USB_COMPLETE_XACTERR: return "XACTERR";
        case CVMX_USB_COMPLETE_DATATGLERR: return "DATATGLERR";
        case CVMX_USB_COMPLETE_BABBLEERR: return "BABBLEERR";
        case CVMX_USB_COMPLETE_FRAMEERR: return "FRAMEERR";
    }
    return "Update __cvmx_usb_complete_to_string";
}


/**
 * @INTERNAL
 * Return non zero if this pipe connects to a non HIGH speed
 * device through a high speed hub.
 *
 * @param usb    USB block this access is for
 * @param pipe   Pipe to check
 *
 * @return Non zero if we need to do split transactions
 */
static inline int __cvmx_usb_pipe_needs_split(cvmx_usb_internal_state_t *usb, cvmx_usb_pipe_t *pipe)
{
    return ((pipe->device_speed != CVMX_USB_SPEED_HIGH) && (usb->usbcx_hprt.s.prtspd == CVMX_USB_SPEED_HIGH));
}


/**
 * @INTERNAL
 * Trivial utility function to return the correct PID for a pipe
 *
 * @param pipe   pipe to check
 *
 * @return PID for pipe
 */
static inline int __cvmx_usb_get_data_pid(cvmx_usb_pipe_t *pipe)
{
    if (pipe->pid_toggle)
        return 2; /* Data1 */
    else
        return 0; /* Data0 */
}


/**
 * Return the number of USB ports supported by this Octeon
 * chip. If the chip doesn't support USB, or is not supported
 * by this API, a zero will be returned. Most Octeon chips
 * support one usb port, but some support two ports.
 * cvmx_usb_initialize() must be called on independent
 * cvmx_usb_state_t structures.
 *
 * This utilizes cvmx_helper_board_usb_get_num_ports()
 * to get any board specific variatons.
 *
 * @return Number of port, zero if usb isn't supported
 */
int cvmx_usb_get_num_ports(void)
{
    int arch_ports = 0;

    if (OCTEON_IS_MODEL(OCTEON_CN52XX))
        arch_ports = 2;
    else if (OCTEON_IS_MODEL(OCTEON_CN31XX))
        arch_ports = 0; /* This chip has USB but it doesn't support DMA */
    else if (OCTEON_IS_MODEL(OCTEON_CN38XX) || OCTEON_IS_MODEL(OCTEON_CN58XX))
        arch_ports = 0;
    else
        arch_ports = 1;

    return __cvmx_helper_board_usb_get_num_ports(arch_ports);
}


/**
 * @INTERNAL
 * Allocate a usb transaction for use
 *
 * @param usb    USB device state populated by
 *               cvmx_usb_initialize().
 *
 * @return Transaction or NULL
 */
static inline cvmx_usb_transaction_t *__cvmx_usb_alloc_transaction(cvmx_usb_internal_state_t *usb)
{
    cvmx_usb_transaction_t *t;
    t = usb->free_transaction_head;
    if (t)
    {
        usb->free_transaction_head = t->next;
        if (!usb->free_transaction_head)
            usb->free_transaction_tail = NULL;
    }
    else if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEBUG_INFO))
        cvmx_dprintf("%s: Failed to allocate a transaction\n", __FUNCTION__);
    if (t)
    {
        memset(t, 0, sizeof(*t));
        t->flags = __CVMX_USB_TRANSACTION_FLAGS_IN_USE;
    }
    return t;
}


/**
 * @INTERNAL
 * Free a usb transaction
 *
 * @param usb    USB device state populated by
 *               cvmx_usb_initialize().
 * @param transaction
 *               Transaction to free
 */
static inline void __cvmx_usb_free_transaction(cvmx_usb_internal_state_t *usb,
                                        cvmx_usb_transaction_t *transaction)
{
    transaction->flags = 0;
    transaction->prev = NULL;
    transaction->next = NULL;
    if (usb->free_transaction_tail)
        usb->free_transaction_tail->next = transaction;
    else
        usb->free_transaction_head = transaction;
    usb->free_transaction_tail = transaction;
}


/**
 * @INTERNAL
 * Add a pipe to the tail of a list
 * @param list   List to add pipe to
 * @param pipe   Pipe to add
 */
static inline void __cvmx_usb_append_pipe(cvmx_usb_pipe_list_t *list, cvmx_usb_pipe_t *pipe)
{
    pipe->next = NULL;
    pipe->prev = list->tail;
    if (list->tail)
        list->tail->next = pipe;
    else
        list->head = pipe;
    list->tail = pipe;
}


/**
 * @INTERNAL
 * Remove a pipe from a list
 * @param list   List to remove pipe from
 * @param pipe   Pipe to remove
 */
static inline void __cvmx_usb_remove_pipe(cvmx_usb_pipe_list_t *list, cvmx_usb_pipe_t *pipe)
{
    if (list->head == pipe)
    {
        list->head = pipe->next;
        pipe->next = NULL;
        if (list->head)
            list->head->prev = NULL;
        else
            list->tail = NULL;
    }
    else if (list->tail == pipe)
    {
        list->tail = pipe->prev;
        list->tail->next = NULL;
        pipe->prev = NULL;
    }
    else
    {
        pipe->prev->next = pipe->next;
        pipe->next->prev = pipe->prev;
        pipe->prev = NULL;
        pipe->next = NULL;
    }
}


/**
 * @INTERNAL
 * Perfrom USB device mode initialization after a reset completes.
 * This should be called after USBC0/1_GINTSTS[USBRESET] and
 * coresponds to section 22.6.1.1, "Initialization on USB Reset",
 * in the manual.
 *
 * @param usb    USB device state populated by
 *               cvmx_usb_initialize().
 *
 * @return CVMX_USB_SUCCESS or a negative error code defined in
 *         cvmx_usb_status_t.
 */
static cvmx_usb_status_t __cvmx_usb_device_reset_complete(cvmx_usb_internal_state_t *usb)
{
    cvmx_usbcx_ghwcfg3_t usbcx_ghwcfg3;
    int i;

    CVMX_USB_LOG_CALLED();
    CVMX_USB_LOG_PARAM("%p", usb);

    /* 1. Set USBC0/1_DOEPCTLn[SNAK] = 1 (for all OUT endpoints, n = 0-4). */
    for (i=0; i<5; i++)
    {
        USB_SET_FIELD32(CVMX_USBCX_DOEPCTLX(i, usb->index),
                        cvmx_usbcx_doepctlx_t, snak, 1);
    }

    /* 2. Unmask the following interrupt bits:
        USBC0/1_DAINTMSK[INEPMSK] = 1 (control 0 IN endpoint)
        USBC0/1_DAINTMSK[OUTEPMSK] = 1 (control 0 OUT endpoint)
        USBC0/1_DOEPMSK[SETUPMSK] = 1
        USBC0/1_DOEPMSK[XFERCOMPLMSK] = 1
        USBC0/1_DIEPMSK[XFERCOMPLMSK] = 1
        USBC0/1_DIEPMSK[TIMEOUTMSK] = 1 */
    USB_SET_FIELD32(CVMX_USBCX_DAINTMSK(usb->index), cvmx_usbcx_daintmsk_t,
                    inepmsk, 1);
    USB_SET_FIELD32(CVMX_USBCX_DAINTMSK(usb->index), cvmx_usbcx_daintmsk_t,
                    outepmsk, 1);
    USB_SET_FIELD32(CVMX_USBCX_DOEPMSK(usb->index), cvmx_usbcx_doepmsk_t,
                    setupmsk, 1);
    USB_SET_FIELD32(CVMX_USBCX_DOEPMSK(usb->index), cvmx_usbcx_doepmsk_t,
                    xfercomplmsk, 1);
    USB_SET_FIELD32(CVMX_USBCX_DIEPMSK(usb->index), cvmx_usbcx_diepmsk_t,
                    xfercomplmsk, 1);
    USB_SET_FIELD32(CVMX_USBCX_DIEPMSK(usb->index), cvmx_usbcx_diepmsk_t,
                    timeoutmsk, 1);

    /* 3. To transmit or receive data, the device must initialize more
        registers as specified in Section 22.6.1.7 */
    /* Nothing needed */

    /* 4. Set up the data FIFO RAM for each of the FIFOs:
        Program USBC0/1_GRXFSIZ to be able to receive control OUT data and
        SETUP data. This must equal at least one maximum packet size of
        control endpoint 0 + 2 Dwords (for the status of the control OUT
        data packet) + 10 Dwords (for SETUP packets).
        Program USBC0/1_GNPTXFSIZ to be able to transmit control IN data. This
        must equal at least one maximum packet size of control endpoint 0. */

    /* Read the HWCFG3 register so we know how much space is in the FIFO */
    usbcx_ghwcfg3.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_GHWCFG3(usb->index));

    {
        cvmx_usbcx_gnptxfsiz_t gnptxfsiz;
        int fifo_space = usbcx_ghwcfg3.s.dfifodepth;
        int i;

        /* Start at the top of the FIFO and assign space for each periodic
            fifo */
        for (i=4;i>0;i--)
        {
            cvmx_usbcx_dptxfsizx_t siz;
            siz.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_DPTXFSIZX(i, usb->index));
            fifo_space -= siz.s.dptxfsize;
            siz.s.dptxfstaddr = fifo_space;
            __cvmx_usb_write_csr32(usb, CVMX_USBCX_DPTXFSIZX(i, usb->index), siz.u32);
        }

        /* Assign half the leftover space to the non periodic tx fifo */
        gnptxfsiz.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_GNPTXFSIZ(usb->index));
        gnptxfsiz.s.nptxfdep = fifo_space / 2;
        fifo_space -= gnptxfsiz.s.nptxfdep;
        gnptxfsiz.s.nptxfstaddr = fifo_space;
        __cvmx_usb_write_csr32(usb, CVMX_USBCX_GNPTXFSIZ(usb->index), gnptxfsiz.u32);

        /* Assign the remain space to the RX fifo */
        USB_SET_FIELD32(CVMX_USBCX_GRXFSIZ(usb->index), cvmx_usbcx_grxfsiz_t,
                        rxfdep, fifo_space);
    }

    /* 5. Program the following fields in the endpoint-specific registers for
        control OUT endpoint 0 to receive a SETUP packet
        USBC0/1_DOEPTSIZ0[SUPCNT] = 0x3 (to receive up to three back-to-back
        SETUP packets)
        In DMA mode, USBC0/1_DOEPDMA0 register with a memory address to
        store any SETUP packets received */
    USB_SET_FIELD32(CVMX_USBCX_DOEPTSIZX(0, usb->index),
                    cvmx_usbcx_doeptsizx_t, mc, 3);
    // FIXME

    /* At this point, all initialization required to receive SETUP packets is
        done. */

    CVMX_USB_RETURN(CVMX_USB_SUCCESS);
}


/**
 * Initialize a USB port for use. This must be called before any
 * other access to the Octeon USB port is made. The port starts
 * off in the disabled state.
 *
 * @param state  Pointer to an empty cvmx_usb_state_t structure
 *               that will be populated by the initialize call.
 *               This structure is then passed to all other USB
 *               functions.
 * @param usb_port_number
 *               Which Octeon USB port to initialize.
 * @param flags  Flags to control hardware initialization. See
 *               cvmx_usb_initialize_flags_t for the flag
 *               definitions. Some flags are mandatory.
 *
 * @return CVMX_USB_SUCCESS or a negative error code defined in
 *         cvmx_usb_status_t.
 */
cvmx_usb_status_t cvmx_usb_initialize(cvmx_usb_state_t *state,
                                      int usb_port_number,
                                      cvmx_usb_initialize_flags_t flags)
{
    cvmx_usbnx_clk_ctl_t usbn_clk_ctl;
    cvmx_usbnx_usbp_ctl_status_t usbn_usbp_ctl_status;
    cvmx_usb_internal_state_t *usb = (cvmx_usb_internal_state_t*)state;

    usb->init_flags = flags;
    CVMX_USB_LOG_CALLED();
    CVMX_USB_LOG_PARAM("%p", state);
    CVMX_USB_LOG_PARAM("%d", usb_port_number);
    CVMX_USB_LOG_PARAM("0x%x", flags);

    /* Make sure that state is large enough to store the internal state */
    if (sizeof(*state) < sizeof(*usb))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    /* At first allow 0-1 for the usb port number */
    if ((usb_port_number < 0) || (usb_port_number > 1))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    /* For all chips except 52XX there is only one port */
    if (!OCTEON_IS_MODEL(OCTEON_CN52XX) && (usb_port_number > 0))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    /* Try to determine clock type automatically */
    if ((flags & (CVMX_USB_INITIALIZE_FLAGS_CLOCK_XO_XI |
                  CVMX_USB_INITIALIZE_FLAGS_CLOCK_XO_GND)) == 0)
    {
        if (__cvmx_helper_board_usb_get_clock_type() == USB_CLOCK_TYPE_CRYSTAL_12)
            flags |= CVMX_USB_INITIALIZE_FLAGS_CLOCK_XO_XI;  /* Only 12 MHZ crystals are supported */
        else
            flags |= CVMX_USB_INITIALIZE_FLAGS_CLOCK_XO_GND;
    }

    if (flags & CVMX_USB_INITIALIZE_FLAGS_CLOCK_XO_GND)
    {
        /* Check for auto ref clock frequency */
        if (!(flags & CVMX_USB_INITIALIZE_FLAGS_CLOCK_MHZ_MASK))
            switch (__cvmx_helper_board_usb_get_clock_type())
            {
                case USB_CLOCK_TYPE_REF_12:
                    flags |= CVMX_USB_INITIALIZE_FLAGS_CLOCK_12MHZ;
                    break;
                case USB_CLOCK_TYPE_REF_24:
                    flags |= CVMX_USB_INITIALIZE_FLAGS_CLOCK_24MHZ;
                    break;
                case USB_CLOCK_TYPE_REF_48:
                    flags |= CVMX_USB_INITIALIZE_FLAGS_CLOCK_48MHZ;
                    break;
                default:
                    CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
                    break;
            }
    }

    memset(usb, 0, sizeof(usb));
    usb->init_flags = flags;

    /* Initialize the USB state structure */
    {
        int i;
        usb->index = usb_port_number;

        /* Initialize the transaction double linked list */
        usb->free_transaction_head = NULL;
        usb->free_transaction_tail = NULL;
        for (i=0; i<MAX_TRANSACTIONS; i++)
            __cvmx_usb_free_transaction(usb, usb->transaction + i);
        for (i=0; i<MAX_PIPES; i++)
            __cvmx_usb_append_pipe(&usb->free_pipes, usb->pipe + i);
    }

    /* Power On Reset and PHY Initialization */

    /* 1. Wait for DCOK to assert (nothing to do) */
    /* 2a. Write USBN0/1_CLK_CTL[POR] = 1 and
        USBN0/1_CLK_CTL[HRST,PRST,HCLK_RST] = 0 */
    usbn_clk_ctl.u64 = __cvmx_usb_read_csr64(usb, CVMX_USBNX_CLK_CTL(usb->index));
    usbn_clk_ctl.s.por = 1;
    usbn_clk_ctl.s.hrst = 0;
    usbn_clk_ctl.s.prst = 0;
    usbn_clk_ctl.s.hclk_rst = 0;
    usbn_clk_ctl.s.enable = 0;
    /* 2b. Select the USB reference clock/crystal parameters by writing
        appropriate values to USBN0/1_CLK_CTL[P_C_SEL, P_RTYPE, P_COM_ON] */
    if (usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_CLOCK_XO_GND)
    {
        /* The USB port uses 12/24/48MHz 2.5V board clock
            source at USB_XO. USB_XI should be tied to GND.
            Most Octeon evaluation boards require this setting */
        if (OCTEON_IS_MODEL(OCTEON_CN3XXX))
        {
            usbn_clk_ctl.cn31xx.p_rclk  = 1; /* From CN31XX,CN30XX manual */
            usbn_clk_ctl.cn31xx.p_xenbn = 0;
        }
        else if (OCTEON_IS_MODEL(OCTEON_CN56XX) || OCTEON_IS_MODEL(OCTEON_CN50XX))
            usbn_clk_ctl.cn56xx.p_rtype = 2; /* From CN56XX,CN50XX manual */
        else
            usbn_clk_ctl.cn52xx.p_rtype = 1; /* From CN52XX manual */

        switch (flags & CVMX_USB_INITIALIZE_FLAGS_CLOCK_MHZ_MASK)
        {
            case CVMX_USB_INITIALIZE_FLAGS_CLOCK_12MHZ:
                usbn_clk_ctl.s.p_c_sel = 0;
                break;
            case CVMX_USB_INITIALIZE_FLAGS_CLOCK_24MHZ:
                usbn_clk_ctl.s.p_c_sel = 1;
                break;
            case CVMX_USB_INITIALIZE_FLAGS_CLOCK_48MHZ:
                usbn_clk_ctl.s.p_c_sel = 2;
                break;
        }
    }
    else
    {
        /* The USB port uses a 12MHz crystal as clock source
            at USB_XO and USB_XI */
        if (OCTEON_IS_MODEL(OCTEON_CN3XXX))
        {
            usbn_clk_ctl.cn31xx.p_rclk  = 1; /* From CN31XX,CN30XX manual */
            usbn_clk_ctl.cn31xx.p_xenbn = 1;
        }
        else if (OCTEON_IS_MODEL(OCTEON_CN56XX) || OCTEON_IS_MODEL(OCTEON_CN50XX))
            usbn_clk_ctl.cn56xx.p_rtype = 0; /* From CN56XX,CN50XX manual */
        else
            usbn_clk_ctl.cn52xx.p_rtype = 0; /* From CN52XX manual */

        usbn_clk_ctl.s.p_c_sel = 0;
    }
    /* 2c. Select the HCLK via writing USBN0/1_CLK_CTL[DIVIDE, DIVIDE2] and
        setting USBN0/1_CLK_CTL[ENABLE] = 1.  Divide the core clock down such
        that USB is as close as possible to 125Mhz */
    {
        int divisor = (cvmx_sysinfo_get()->cpu_clock_hz+125000000-1)/125000000;
        if (divisor < 4)  /* Lower than 4 doesn't seem to work properly */
            divisor = 4;
        usbn_clk_ctl.s.divide = divisor;
        usbn_clk_ctl.s.divide2 = 0;
    }
    __cvmx_usb_write_csr64(usb, CVMX_USBNX_CLK_CTL(usb->index),
                           usbn_clk_ctl.u64);
    /* 2d. Write USBN0/1_CLK_CTL[HCLK_RST] = 1 */
    usbn_clk_ctl.s.hclk_rst = 1;
    __cvmx_usb_write_csr64(usb, CVMX_USBNX_CLK_CTL(usb->index),
                           usbn_clk_ctl.u64);
    /* 2e.  Wait 64 core-clock cycles for HCLK to stabilize */
    cvmx_wait(64);
    /* 3. Program the power-on reset field in the USBN clock-control register:
        USBN_CLK_CTL[POR] = 0 */
    usbn_clk_ctl.s.por = 0;
    __cvmx_usb_write_csr64(usb, CVMX_USBNX_CLK_CTL(usb->index),
                           usbn_clk_ctl.u64);
    /* 4. Wait 1 ms for PHY clock to start */
    cvmx_wait_usec(1000);
    /* 5. Program the Reset input from automatic test equipment field in the
        USBP control and status register: USBN_USBP_CTL_STATUS[ATE_RESET] = 1 */
    usbn_usbp_ctl_status.u64 = __cvmx_usb_read_csr64(usb, CVMX_USBNX_USBP_CTL_STATUS(usb->index));
    usbn_usbp_ctl_status.s.ate_reset = 1;
    __cvmx_usb_write_csr64(usb, CVMX_USBNX_USBP_CTL_STATUS(usb->index),
                           usbn_usbp_ctl_status.u64);
    /* 6. Wait 10 cycles */
    cvmx_wait(10);
    /* 7. Clear ATE_RESET field in the USBN clock-control register:
        USBN_USBP_CTL_STATUS[ATE_RESET] = 0 */
    usbn_usbp_ctl_status.s.ate_reset = 0;
    __cvmx_usb_write_csr64(usb, CVMX_USBNX_USBP_CTL_STATUS(usb->index),
                           usbn_usbp_ctl_status.u64);
    /* 8. Program the PHY reset field in the USBN clock-control register:
        USBN_CLK_CTL[PRST] = 1 */
    usbn_clk_ctl.s.prst = 1;
    __cvmx_usb_write_csr64(usb, CVMX_USBNX_CLK_CTL(usb->index),
                           usbn_clk_ctl.u64);
    /* 9. Program the USBP control and status register to select host or
        device mode. USBN_USBP_CTL_STATUS[HST_MODE] = 0 for host, = 1 for
        device */
    if (usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEVICE_MODE)
    {
        usbn_usbp_ctl_status.s.hst_mode = 1;
        usbn_usbp_ctl_status.s.dm_pulld = 0;
        usbn_usbp_ctl_status.s.dp_pulld = 0;
    }
    else
    {
        usbn_usbp_ctl_status.s.hst_mode = 0;
    }
    __cvmx_usb_write_csr64(usb, CVMX_USBNX_USBP_CTL_STATUS(usb->index),
                           usbn_usbp_ctl_status.u64);
    /* 10. Wait 1 �s */
    cvmx_wait_usec(1);
    /* 11. Program the hreset_n field in the USBN clock-control register:
        USBN_CLK_CTL[HRST] = 1 */
    usbn_clk_ctl.s.hrst = 1;
    __cvmx_usb_write_csr64(usb, CVMX_USBNX_CLK_CTL(usb->index),
                           usbn_clk_ctl.u64);
    /* 12. Proceed to USB core initialization */
    usbn_clk_ctl.s.enable = 1;
    __cvmx_usb_write_csr64(usb, CVMX_USBNX_CLK_CTL(usb->index),
                           usbn_clk_ctl.u64);
    cvmx_wait_usec(1);

    /* USB Core Initialization */

    /* 1. Read USBC_GHWCFG1, USBC_GHWCFG2, USBC_GHWCFG3, USBC_GHWCFG4 to
        determine USB core configuration parameters. */
    /* Nothing needed */
    /* 2. Program the following fields in the global AHB configuration
        register (USBC_GAHBCFG)
        DMA mode, USBC_GAHBCFG[DMAEn]: 1 = DMA mode, 0 = slave mode
        Burst length, USBC_GAHBCFG[HBSTLEN] = 0
        Nonperiodic TxFIFO empty level (slave mode only),
        USBC_GAHBCFG[NPTXFEMPLVL]
        Periodic TxFIFO empty level (slave mode only),
        USBC_GAHBCFG[PTXFEMPLVL]
        Global interrupt mask, USBC_GAHBCFG[GLBLINTRMSK] = 1 */
    {
        cvmx_usbcx_gahbcfg_t usbcx_gahbcfg;
        usbcx_gahbcfg.u32 = 0;
        usbcx_gahbcfg.s.dmaen = !OCTEON_IS_MODEL(OCTEON_CN31XX);
        /* If we are using DMA, start off with 8 idle channels. Without
            DMA we emulate a single channel */
        if (usbcx_gahbcfg.s.dmaen)
            usb->idle_hardware_channels = 0xff;
        else
            usb->idle_hardware_channels = 0x1;
        usbcx_gahbcfg.s.hbstlen = 0;
        usbcx_gahbcfg.s.nptxfemplvl = 1;
        usbcx_gahbcfg.s.ptxfemplvl = 1;
        usbcx_gahbcfg.s.glblintrmsk = 1;
        __cvmx_usb_write_csr32(usb, CVMX_USBCX_GAHBCFG(usb->index),
                               usbcx_gahbcfg.u32);
    }
    /* 3. Program the following fields in USBC_GUSBCFG register.
        HS/FS timeout calibration, USBC_GUSBCFG[TOUTCAL] = 0
        ULPI DDR select, USBC_GUSBCFG[DDRSEL] = 0
        USB turnaround time, USBC_GUSBCFG[USBTRDTIM] = 0x5
        PHY low-power clock select, USBC_GUSBCFG[PHYLPWRCLKSEL] = 0 */
    {
        cvmx_usbcx_gusbcfg_t usbcx_gusbcfg;
        usbcx_gusbcfg.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_GUSBCFG(usb->index));
        usbcx_gusbcfg.s.toutcal = 0;
        usbcx_gusbcfg.s.ddrsel = 0;
        usbcx_gusbcfg.s.usbtrdtim = 0x5;
        usbcx_gusbcfg.s.phylpwrclksel = 0;
        __cvmx_usb_write_csr32(usb, CVMX_USBCX_GUSBCFG(usb->index),
                               usbcx_gusbcfg.u32);
    }
    /* 4. The software must unmask the following bits in the USBC_GINTMSK
        register.
        OTG interrupt mask, USBC_GINTMSK[OTGINTMSK] = 1
        Mode mismatch interrupt mask, USBC_GINTMSK[MODEMISMSK] = 1 */
    {
        cvmx_usbcx_gintmsk_t usbcx_gintmsk;
        cvmx_usbcx_hcintmskx_t usbc_hcintmsk;
        cvmx_usbcx_haintmsk_t usbc_haintmsk;
        int channel;

        usbcx_gintmsk.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_GINTMSK(usb->index));
        usbcx_gintmsk.s.otgintmsk = 1;
        usbcx_gintmsk.s.modemismsk = 1;
        usbcx_gintmsk.s.hchintmsk = 1;
        usbcx_gintmsk.s.sofmsk = 0;
        __cvmx_usb_write_csr32(usb, CVMX_USBCX_GINTMSK(usb->index),
                               usbcx_gintmsk.u32);

        /* Enable the channel halt interrupt */
        usbc_hcintmsk.u32 = 0;
        usbc_hcintmsk.s.chhltdmsk = 1;
        for (channel=0; channel<8; channel++)
            if (usb->idle_hardware_channels & (1<<channel))
                __cvmx_usb_write_csr32(usb, CVMX_USBCX_HCINTMSKX(channel, usb->index), usbc_hcintmsk.u32);

        /* Enable the channel interrupt to propagate */
        usbc_haintmsk.u32 = 0;
        usbc_haintmsk.s.haintmsk = usb->idle_hardware_channels;
        __cvmx_usb_write_csr32(usb, CVMX_USBCX_HAINTMSK(usb->index), usbc_haintmsk.u32);
    }

    if ((usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEVICE_MODE) == 0)
    {
        /* Host Port Initialization */
        if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEBUG_INFO))
            cvmx_dprintf("%s: USB%d is in host mode\n", __FUNCTION__, usb->index);

        /* 1. Program the host-port interrupt-mask field to unmask,
            USBC_GINTMSK[PRTINT] = 1 */
        USB_SET_FIELD32(CVMX_USBCX_GINTMSK(usb->index), cvmx_usbcx_gintmsk_t,
                        prtintmsk, 1);
        USB_SET_FIELD32(CVMX_USBCX_GINTMSK(usb->index), cvmx_usbcx_gintmsk_t,
                        disconnintmsk, 1);
        /* 2. Program the USBC_HCFG register to select full-speed host or
            high-speed host. */
        {
            cvmx_usbcx_hcfg_t usbcx_hcfg;
            usbcx_hcfg.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_HCFG(usb->index));
            usbcx_hcfg.s.fslssupp = 0;
            usbcx_hcfg.s.fslspclksel = 0;
            __cvmx_usb_write_csr32(usb, CVMX_USBCX_HCFG(usb->index), usbcx_hcfg.u32);
        }
        /* 3. Program the port power bit to drive VBUS on the USB,
            USBC_HPRT[PRTPWR] = 1 */
        USB_SET_FIELD32(CVMX_USBCX_HPRT(usb->index), cvmx_usbcx_hprt_t, prtpwr, 1);

        /* Steps 4-15 from the manual are done later in the port enable */
    }
    else
    {
        /* Device Port Initialization */
        if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEBUG_INFO))
            cvmx_dprintf("%s: USB%d is in device mode\n", __FUNCTION__, usb->index);

        /* 1. Program the following fields in the USBC0/1_DCFG register:
            Device speed, USBC0/1_DCFG[DEVSPD] = 0 (high speed)
            Non-zero-length status OUT handshake, USBC0/1_DCFG[NZSTSOUTHSHK]=0
            Periodic frame interval (if periodic endpoints are supported),
            USBC0/1_DCFG[PERFRINT] = 1 */
        USB_SET_FIELD32(CVMX_USBCX_DCFG(usb->index), cvmx_usbcx_dcfg_t,
                        devspd, 0);
        USB_SET_FIELD32(CVMX_USBCX_DCFG(usb->index), cvmx_usbcx_dcfg_t,
                        nzstsouthshk, 0);
        USB_SET_FIELD32(CVMX_USBCX_DCFG(usb->index), cvmx_usbcx_dcfg_t,
                        perfrint, 1);

        /* 2. Program the USBC0/1_GINTMSK register to unmask the following
            interrupts:
            USB Reset, USBC0/1_GINTMSK[USBRSTMSK] = 1
            Enumeration done, USBC0/1_GINTMSK[ENUMDONEMSK] = 1
            SOF, USBC0/1_GINTMSK[SOFMSK] = 1 */
        USB_SET_FIELD32(CVMX_USBCX_GINTMSK(usb->index), cvmx_usbcx_gintmsk_t,
                        usbrstmsk, 1);
        USB_SET_FIELD32(CVMX_USBCX_GINTMSK(usb->index), cvmx_usbcx_gintmsk_t,
                        enumdonemsk, 1);
        USB_SET_FIELD32(CVMX_USBCX_GINTMSK(usb->index), cvmx_usbcx_gintmsk_t,
                        sofmsk, 1);

        /* 3. Wait for the USBC0/1_GINTSTS[USBRESET] interrupt, which
            indicates a reset has been detected on the USB and lasts for
            about 10 ms. On receiving this interrupt, the application must
            perform the steps listed in Section 22.6.1.1, "Initialization on
            USB Reset". */
        /* Handled in cvmx_poll() usbc_gintsts.s.usbrst processing */

        /* 4. Wait for the USBC0/1_GINTSTS[ENUMERATIONDONE] interrupt, which
            indicates the end of reset on the USB. On receiving this interrupt,
            the application must read the USBC0/1_DSTS register to determine
            the enumeration speed and perform the steps listed in Section
            22.6.1.2, "Initialization on Enumeration Completion". */
        /* Handled in cvmx_poll() usbc_gintsts.s.enumdone processing */
    }

    CVMX_USB_RETURN(CVMX_USB_SUCCESS);
}


/**
 * Shutdown a USB port after a call to cvmx_usb_initialize().
 * The port should be disabled with all pipes closed when this
 * function is called.
 *
 * @param state  USB device state populated by
 *               cvmx_usb_initialize().
 *
 * @return CVMX_USB_SUCCESS or a negative error code defined in
 *         cvmx_usb_status_t.
 */
cvmx_usb_status_t cvmx_usb_shutdown(cvmx_usb_state_t *state)
{
    cvmx_usbnx_clk_ctl_t usbn_clk_ctl;
    cvmx_usb_internal_state_t *usb = (cvmx_usb_internal_state_t*)state;

    CVMX_USB_LOG_CALLED();
    CVMX_USB_LOG_PARAM("%p", state);

    /* Make sure all pipes are closed */
    if (usb->idle_pipes.head ||
        usb->active_pipes[CVMX_USB_TRANSFER_ISOCHRONOUS].head ||
        usb->active_pipes[CVMX_USB_TRANSFER_INTERRUPT].head ||
        usb->active_pipes[CVMX_USB_TRANSFER_CONTROL].head ||
        usb->active_pipes[CVMX_USB_TRANSFER_BULK].head)
        CVMX_USB_RETURN(CVMX_USB_BUSY);

    /* Disable the clocks and put them in power on reset */
    usbn_clk_ctl.u64 = __cvmx_usb_read_csr64(usb, CVMX_USBNX_CLK_CTL(usb->index));
    usbn_clk_ctl.s.enable = 1;
    usbn_clk_ctl.s.por = 1;
    usbn_clk_ctl.s.hclk_rst = 1;
    usbn_clk_ctl.s.prst = 0;
    usbn_clk_ctl.s.hrst = 0;
    __cvmx_usb_write_csr64(usb, CVMX_USBNX_CLK_CTL(usb->index),
                           usbn_clk_ctl.u64);
    CVMX_USB_RETURN(CVMX_USB_SUCCESS);
}


/**
 * Enable a USB port. After this call succeeds, the USB port is
 * online and servicing requests.
 *
 * @param state  USB device state populated by
 *               cvmx_usb_initialize().
 *
 * @return CVMX_USB_SUCCESS or a negative error code defined in
 *         cvmx_usb_status_t.
 */
cvmx_usb_status_t cvmx_usb_enable(cvmx_usb_state_t *state)
{
    cvmx_usbcx_ghwcfg3_t usbcx_ghwcfg3;
    cvmx_usb_internal_state_t *usb = (cvmx_usb_internal_state_t*)state;

    CVMX_USB_LOG_CALLED();
    CVMX_USB_LOG_PARAM("%p", state);
    if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEVICE_MODE))
        CVMX_USB_RETURN(CVMX_USB_INCORRECT_MODE);

    usb->usbcx_hprt.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_HPRT(usb->index));

    /* If the port is already enabled the just return. We don't need to do
        anything */
    if (usb->usbcx_hprt.s.prtena)
        CVMX_USB_RETURN(CVMX_USB_SUCCESS);

    /* If there is nothing plugged into the port then fail immediately */
    if (!usb->usbcx_hprt.s.prtconnsts)
    {
        if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEBUG_INFO))
            cvmx_dprintf("%s: USB%d Nothing plugged into the port\n", __FUNCTION__, usb->index);
        CVMX_USB_RETURN(CVMX_USB_TIMEOUT);
    }

    /* Program the port reset bit to start the reset process */
    USB_SET_FIELD32(CVMX_USBCX_HPRT(usb->index), cvmx_usbcx_hprt_t, prtrst, 1);

    /* Wait at least 50ms (high speed), or 10ms (full speed) for the reset
        process to complete. */
    cvmx_wait_usec(50000);

    /* Program the port reset bit to 0, USBC_HPRT[PRTRST] = 0 */
    USB_SET_FIELD32(CVMX_USBCX_HPRT(usb->index), cvmx_usbcx_hprt_t, prtrst, 0);

    /* Wait for the USBC_HPRT[PRTENA]. */
    if (CVMX_WAIT_FOR_FIELD32(CVMX_USBCX_HPRT(usb->index), cvmx_usbcx_hprt_t,
                              prtena, ==, 1, 100000))
    {
        if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEBUG_INFO))
            cvmx_dprintf("%s: Timeout waiting for the port to finish reset\n",
                         __FUNCTION__);
        CVMX_USB_RETURN(CVMX_USB_TIMEOUT);
    }

    /* Read the port speed field to get the enumerated speed, USBC_HPRT[PRTSPD]. */
    usb->usbcx_hprt.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_HPRT(usb->index));
    if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEBUG_INFO))
        cvmx_dprintf("%s: USB%d is in %s speed mode\n", __FUNCTION__, usb->index,
                     (usb->usbcx_hprt.s.prtspd == CVMX_USB_SPEED_HIGH) ? "high" :
                     (usb->usbcx_hprt.s.prtspd == CVMX_USB_SPEED_FULL) ? "full" :
                     "low");

    usbcx_ghwcfg3.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_GHWCFG3(usb->index));

    /* 13. Program the USBC_GRXFSIZ register to select the size of the receive
        FIFO (25%). */
    USB_SET_FIELD32(CVMX_USBCX_GRXFSIZ(usb->index), cvmx_usbcx_grxfsiz_t,
                    rxfdep, usbcx_ghwcfg3.s.dfifodepth / 4);
    /* 14. Program the USBC_GNPTXFSIZ register to select the size and the
        start address of the non- periodic transmit FIFO for nonperiodic
        transactions (50%). */
    {
        cvmx_usbcx_gnptxfsiz_t siz;
        siz.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_GNPTXFSIZ(usb->index));
        siz.s.nptxfdep = usbcx_ghwcfg3.s.dfifodepth / 2;
        siz.s.nptxfstaddr = usbcx_ghwcfg3.s.dfifodepth / 4;
        __cvmx_usb_write_csr32(usb, CVMX_USBCX_GNPTXFSIZ(usb->index), siz.u32);
    }
    /* 15. Program the USBC_HPTXFSIZ register to select the size and start
        address of the periodic transmit FIFO for periodic transactions (25%). */
    {
        cvmx_usbcx_hptxfsiz_t siz;
        siz.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_HPTXFSIZ(usb->index));
        siz.s.ptxfsize = usbcx_ghwcfg3.s.dfifodepth / 4;
        siz.s.ptxfstaddr = 3 * usbcx_ghwcfg3.s.dfifodepth / 4;
        __cvmx_usb_write_csr32(usb, CVMX_USBCX_HPTXFSIZ(usb->index), siz.u32);
    }
    /* Flush all FIFOs */
    USB_SET_FIELD32(CVMX_USBCX_GRSTCTL(usb->index), cvmx_usbcx_grstctl_t, txfnum, 0x10);
    USB_SET_FIELD32(CVMX_USBCX_GRSTCTL(usb->index), cvmx_usbcx_grstctl_t, txfflsh, 1);
    CVMX_WAIT_FOR_FIELD32(CVMX_USBCX_GRSTCTL(usb->index), cvmx_usbcx_grstctl_t,
                          txfflsh, ==, 0, 100);
    USB_SET_FIELD32(CVMX_USBCX_GRSTCTL(usb->index), cvmx_usbcx_grstctl_t, rxfflsh, 1);
    CVMX_WAIT_FOR_FIELD32(CVMX_USBCX_GRSTCTL(usb->index), cvmx_usbcx_grstctl_t,
                          rxfflsh, ==, 0, 100);

    CVMX_USB_RETURN(CVMX_USB_SUCCESS);
}


/**
 * Disable a USB port. After this call the USB port will not
 * generate data transfers and will not generate events.
 * Transactions in process will fail and call their
 * associated callbacks.
 *
 * @param state  USB device state populated by
 *               cvmx_usb_initialize().
 *
 * @return CVMX_USB_SUCCESS or a negative error code defined in
 *         cvmx_usb_status_t.
 */
cvmx_usb_status_t cvmx_usb_disable(cvmx_usb_state_t *state)
{
    cvmx_usb_internal_state_t *usb = (cvmx_usb_internal_state_t*)state;

    CVMX_USB_LOG_CALLED();
    CVMX_USB_LOG_PARAM("%p", state);
    if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEVICE_MODE))
        CVMX_USB_RETURN(CVMX_USB_INCORRECT_MODE);

    /* Disable the port */
    USB_SET_FIELD32(CVMX_USBCX_HPRT(usb->index), cvmx_usbcx_hprt_t, prtena, 1);
    CVMX_USB_RETURN(CVMX_USB_SUCCESS);
}


/**
 * Get the current state of the USB port. Use this call to
 * determine if the usb port has anything connected, is enabled,
 * or has some sort of error condition. The return value of this
 * call has "changed" bits to signal of the value of some fields
 * have changed between calls. These "changed" fields are based
 * on the last call to cvmx_usb_set_status(). In order to clear
 * them, you must update the status through cvmx_usb_set_status().
 *
 * @param state  USB device state populated by
 *               cvmx_usb_initialize().
 *
 * @return Port status information
 */
cvmx_usb_port_status_t cvmx_usb_get_status(cvmx_usb_state_t *state)
{
    cvmx_usbcx_hprt_t usbc_hprt;
    cvmx_usb_port_status_t result;
    cvmx_usb_internal_state_t *usb = (cvmx_usb_internal_state_t*)state;

    memset(&result, 0, sizeof(result));

    CVMX_USB_LOG_CALLED();
    CVMX_USB_LOG_PARAM("%p", state);

    usbc_hprt.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_HPRT(usb->index));
    result.port_enabled = usbc_hprt.s.prtena;
    result.port_over_current = usbc_hprt.s.prtovrcurract;
    result.port_powered = usbc_hprt.s.prtpwr;
    result.port_speed = usbc_hprt.s.prtspd;
    result.connected = usbc_hprt.s.prtconnsts;
    result.connect_change = (result.connected != usb->port_status.connected);

    if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEBUG_CALLS))
        cvmx_dprintf("%*s%s: returned port enabled=%d, over_current=%d, powered=%d, speed=%d, connected=%d, connect_change=%d\n",
                     2*(--usb->indent), "", __FUNCTION__,
                     result.port_enabled,
                     result.port_over_current,
                     result.port_powered,
                     result.port_speed,
                     result.connected,
                     result.connect_change);
    return result;
}


/**
 * Set the current state of the USB port. The status is used as
 * a reference for the "changed" bits returned by
 * cvmx_usb_get_status(). Other than serving as a reference, the
 * status passed to this function is not used. No fields can be
 * changed through this call.
 *
 * @param state  USB device state populated by
 *               cvmx_usb_initialize().
 * @param port_status
 *               Port status to set, most like returned by cvmx_usb_get_status()
 */
void cvmx_usb_set_status(cvmx_usb_state_t *state, cvmx_usb_port_status_t port_status)
{
    cvmx_usb_internal_state_t *usb = (cvmx_usb_internal_state_t*)state;
    CVMX_USB_LOG_CALLED();
    CVMX_USB_LOG_PARAM("%p", state);
    usb->port_status = port_status;
    CVMX_USB_RETURN_NOTHING();
}


/**
 * @INTERNAL
 * Convert a USB transaction into a handle
 *
 * @param usb    USB device state populated by
 *               cvmx_usb_initialize().
 * @param transaction
 *               Transaction to get handle for
 *
 * @return Handle
 */
static inline int __cvmx_usb_get_submit_handle(cvmx_usb_internal_state_t *usb,
                                        cvmx_usb_transaction_t *transaction)
{
    return ((unsigned long)transaction - (unsigned long)usb->transaction) /
            sizeof(*transaction);
}


/**
 * @INTERNAL
 * Convert a USB pipe into a handle
 *
 * @param usb    USB device state populated by
 *               cvmx_usb_initialize().
 * @param pipe   Pipe to get handle for
 *
 * @return Handle
 */
static inline int __cvmx_usb_get_pipe_handle(cvmx_usb_internal_state_t *usb,
                                        cvmx_usb_pipe_t *pipe)
{
    return ((unsigned long)pipe - (unsigned long)usb->pipe) / sizeof(*pipe);
}


/**
 * Open a virtual pipe between the host and a USB device. A pipe
 * must be opened before data can be transferred between a device
 * and Octeon.
 *
 * @param state      USB device state populated by
 *                   cvmx_usb_initialize().
 * @param flags      Optional pipe flags defined in
 *                   cvmx_usb_pipe_flags_t.
 * @param device_addr
 *                   USB device address to open the pipe to
 *                   (0-127).
 * @param endpoint_num
 *                   USB endpoint number to open the pipe to
 *                   (0-15).
 * @param device_speed
 *                   The speed of the device the pipe is going
 *                   to. This must match the device's speed,
 *                   which may be different than the port speed.
 * @param max_packet The maximum packet length the device can
 *                   transmit/receive (low speed=0-8, full
 *                   speed=0-1023, high speed=0-1024). This value
 *                   comes from the stadnard endpoint descriptor
 *                   field wMaxPacketSize bits <10:0>.
 * @param transfer_type
 *                   The type of transfer this pipe is for.
 * @param transfer_dir
 *                   The direction the pipe is in. This is not
 *                   used for control pipes.
 * @param interval   For ISOCHRONOUS and INTERRUPT transfers,
 *                   this is how often the transfer is scheduled
 *                   for. All other transfers should specify
 *                   zero. The units are in frames (8000/sec at
 *                   high speed, 1000/sec for full speed).
 * @param multi_count
 *                   For high speed devices, this is the maximum
 *                   allowed number of packet per microframe.
 *                   Specify zero for non high speed devices. This
 *                   value comes from the stadnard endpoint descriptor
 *                   field wMaxPacketSize bits <12:11>.
 * @param hub_device_addr
 *                   Hub device address this device is connected
 *                   to. Devices connected directly to Octeon
 *                   use zero. This is only used when the device
 *                   is full/low speed behind a high speed hub.
 *                   The address will be of the high speed hub,
 *                   not and full speed hubs after it.
 * @param hub_port   Which port on the hub the device is
 *                   connected. Use zero for devices connected
 *                   directly to Octeon. Like hub_device_addr,
 *                   this is only used for full/low speed
 *                   devices behind a high speed hub.
 *
 * @return A non negative value is a pipe handle. Negative
 *         values are failure codes from cvmx_usb_status_t.
 */
int cvmx_usb_open_pipe(cvmx_usb_state_t *state, cvmx_usb_pipe_flags_t flags,
                       int device_addr, int endpoint_num,
                       cvmx_usb_speed_t device_speed, int max_packet,
                       cvmx_usb_transfer_t transfer_type,
                       cvmx_usb_direction_t transfer_dir, int interval,
                       int multi_count, int hub_device_addr, int hub_port)
{
    cvmx_usb_pipe_t *pipe;
    cvmx_usb_internal_state_t *usb = (cvmx_usb_internal_state_t*)state;

    CVMX_USB_LOG_CALLED();
    CVMX_USB_LOG_PARAM("%p", state);
    CVMX_USB_LOG_PARAM("0x%x", flags);
    CVMX_USB_LOG_PARAM("%d", device_addr);
    CVMX_USB_LOG_PARAM("%d", endpoint_num);
    CVMX_USB_LOG_PARAM("%d", device_speed);
    CVMX_USB_LOG_PARAM("%d", max_packet);
    CVMX_USB_LOG_PARAM("%d", transfer_type);
    CVMX_USB_LOG_PARAM("%d", transfer_dir);
    CVMX_USB_LOG_PARAM("%d", interval);
    CVMX_USB_LOG_PARAM("%d", multi_count);
    CVMX_USB_LOG_PARAM("%d", hub_device_addr);
    CVMX_USB_LOG_PARAM("%d", hub_port);

    if (cvmx_unlikely((device_addr < 0) || (device_addr > MAX_USB_ADDRESS)))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely((endpoint_num < 0) || (endpoint_num > MAX_USB_ENDPOINT)))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely(device_speed > CVMX_USB_SPEED_LOW))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely((max_packet <= 0) || (max_packet > 1024)))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely(transfer_type > CVMX_USB_TRANSFER_INTERRUPT))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely((transfer_dir != CVMX_USB_DIRECTION_OUT) &&
        (transfer_dir != CVMX_USB_DIRECTION_IN)))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely(interval < 0))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely((transfer_type == CVMX_USB_TRANSFER_CONTROL) && interval))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely(multi_count < 0))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely((device_speed != CVMX_USB_SPEED_HIGH) &&
        (multi_count != 0)))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely((hub_device_addr < 0) || (hub_device_addr > MAX_USB_ADDRESS)))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely((hub_port < 0) || (hub_port > MAX_USB_HUB_PORT)))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEVICE_MODE))
        CVMX_USB_RETURN(CVMX_USB_INCORRECT_MODE);

    /* Find a free pipe */
    pipe = usb->free_pipes.head;
    if (!pipe)
        CVMX_USB_RETURN(CVMX_USB_NO_MEMORY);
    __cvmx_usb_remove_pipe(&usb->free_pipes, pipe);
    pipe->flags = flags | __CVMX_USB_PIPE_FLAGS_OPEN;
    if ((device_speed == CVMX_USB_SPEED_HIGH) &&
        (transfer_dir == CVMX_USB_DIRECTION_OUT) &&
        (transfer_type == CVMX_USB_TRANSFER_BULK))
        pipe->flags |= __CVMX_USB_PIPE_FLAGS_NEED_PING;
    pipe->device_addr = device_addr;
    pipe->endpoint_num = endpoint_num;
    pipe->device_speed = device_speed;
    pipe->max_packet = max_packet;
    pipe->transfer_type = transfer_type;
    pipe->transfer_dir = transfer_dir;
    /* All pipes use interval to rate limit NAK processing. Force an interval
        if one wasn't supplied */
    if (!interval)
        interval = 1;
    if (device_speed == CVMX_USB_SPEED_HIGH)
        pipe->interval = (uint64_t)interval * cvmx_sysinfo_get()->cpu_clock_hz / 8000;
    else
        pipe->interval = (uint64_t)interval * cvmx_sysinfo_get()->cpu_clock_hz / 1000;
    pipe->multi_count = multi_count;
    pipe->hub_device_addr = hub_device_addr;
    pipe->hub_port = hub_port;
    pipe->pid_toggle = 0;
    pipe->next_tx_cycle = cvmx_read64_uint64(CVMX_IPD_CLK_COUNT) + pipe->interval;
    pipe->split_sc_frame = -1;
    __cvmx_usb_append_pipe(&usb->idle_pipes, pipe);

    /* We don't need to tell the hardware about this pipe yet since
        it doesn't have any submitted requests */

    CVMX_USB_RETURN(__cvmx_usb_get_pipe_handle(usb, pipe));
}


/**
 * @INTERNAL
 * Perform channel specific setup for Control transactions. All
 * the generic stuff will already have been done in
 * __cvmx_usb_start_channel()
 *
 * @param usb     USB device state populated by
 *                cvmx_usb_initialize().
 * @param channel Channel to setup
 * @param pipe    Pipe for control transaction
 */
static void __cvmx_usb_start_channel_control(cvmx_usb_internal_state_t *usb,
                                             int channel,
                                             cvmx_usb_pipe_t *pipe)
{
    cvmx_usb_transaction_t *transaction = pipe->head;
    cvmx_usb_control_header_t *header = cvmx_phys_to_ptr(transaction->control_header);
    int bytes_to_transfer = transaction->buffer_length - transaction->actual_bytes;
    cvmx_usbcx_hctsizx_t usbc_hctsiz;

    CVMX_USB_LOG_CALLED();
    CVMX_USB_LOG_PARAM("%p", usb);
    CVMX_USB_LOG_PARAM("%d", channel);
    CVMX_USB_LOG_PARAM("%p", pipe);

    usbc_hctsiz.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_HCTSIZX(channel, usb->index));

    switch (transaction->stage)
    {
        case CVMX_USB_STAGE_NON_CONTROL:
        case CVMX_USB_STAGE_NON_CONTROL_SPLIT_COMPLETE:
            cvmx_dprintf("%s: ERROR - Non control stage\n", __FUNCTION__);
            break;
        case CVMX_USB_STAGE_SETUP:
            usbc_hctsiz.s.pid = 3; /* Setup */
            usbc_hctsiz.s.xfersize = sizeof(*header);
            /* All Control operations start with a setup going OUT */
            USB_SET_FIELD32(CVMX_USBCX_HCCHARX(channel, usb->index), cvmx_usbcx_hccharx_t, epdir, CVMX_USB_DIRECTION_OUT);
            /* Setup send the control header instead of the buffer data. The
                buffer data will be used in the next stage */
            __cvmx_usb_write_csr64(usb, CVMX_USBNX_DMA0_OUTB_CHN0(usb->index) + channel*8, transaction->control_header);
            break;
        case CVMX_USB_STAGE_SETUP_SPLIT_COMPLETE:
            usbc_hctsiz.s.pid = 3; /* Setup */
            usbc_hctsiz.s.xfersize = 0;
            /* All Control operations start with a setup going OUT */
            USB_SET_FIELD32(CVMX_USBCX_HCCHARX(channel, usb->index), cvmx_usbcx_hccharx_t, epdir, CVMX_USB_DIRECTION_OUT);
            USB_SET_FIELD32(CVMX_USBCX_HCSPLTX(channel, usb->index), cvmx_usbcx_hcspltx_t, compsplt, 1);
            break;
        case CVMX_USB_STAGE_DATA:
            usbc_hctsiz.s.pid = __cvmx_usb_get_data_pid(pipe);
            if (__cvmx_usb_pipe_needs_split(usb, pipe))
            {
                usbc_hctsiz.s.xfersize = (header->s.request_type & 0x80) ? 0 : bytes_to_transfer;
                if (usbc_hctsiz.s.xfersize > pipe->max_packet)
                    usbc_hctsiz.s.xfersize = pipe->max_packet;
            }
            else
                usbc_hctsiz.s.xfersize = bytes_to_transfer;
            USB_SET_FIELD32(CVMX_USBCX_HCCHARX(channel, usb->index),
                            cvmx_usbcx_hccharx_t, epdir,
                            ((header->s.request_type & 0x80) ?
                             CVMX_USB_DIRECTION_IN :
                             CVMX_USB_DIRECTION_OUT));
            break;
        case CVMX_USB_STAGE_DATA_SPLIT_COMPLETE:
            usbc_hctsiz.s.pid = __cvmx_usb_get_data_pid(pipe);
            usbc_hctsiz.s.xfersize = (header->s.request_type & 0x80) ? bytes_to_transfer : 0;
            USB_SET_FIELD32(CVMX_USBCX_HCCHARX(channel, usb->index),
                            cvmx_usbcx_hccharx_t, epdir,
                            ((header->s.request_type & 0x80) ?
                             CVMX_USB_DIRECTION_IN :
                             CVMX_USB_DIRECTION_OUT));
            USB_SET_FIELD32(CVMX_USBCX_HCSPLTX(channel, usb->index), cvmx_usbcx_hcspltx_t, compsplt, 1);
            break;
        case CVMX_USB_STAGE_STATUS:
            usbc_hctsiz.s.pid = __cvmx_usb_get_data_pid(pipe);
            usbc_hctsiz.s.xfersize = 0;
            USB_SET_FIELD32(CVMX_USBCX_HCCHARX(channel, usb->index), cvmx_usbcx_hccharx_t, epdir,
                            ((header->s.request_type & 0x80) ?
                             CVMX_USB_DIRECTION_OUT :
                             CVMX_USB_DIRECTION_IN));
            break;
        case CVMX_USB_STAGE_STATUS_SPLIT_COMPLETE:
            usbc_hctsiz.s.pid = __cvmx_usb_get_data_pid(pipe);
            usbc_hctsiz.s.xfersize = 0;
            USB_SET_FIELD32(CVMX_USBCX_HCCHARX(channel, usb->index), cvmx_usbcx_hccharx_t, epdir,
                            ((header->s.request_type & 0x80) ?
                             CVMX_USB_DIRECTION_OUT :
                             CVMX_USB_DIRECTION_IN));
            USB_SET_FIELD32(CVMX_USBCX_HCSPLTX(channel, usb->index), cvmx_usbcx_hcspltx_t, compsplt, 1);
            break;
    }

    /* Set the number of packets needed for this transfer */
    usbc_hctsiz.s.pktcnt = (usbc_hctsiz.s.xfersize + pipe->max_packet - 1) / pipe->max_packet;
    if (!usbc_hctsiz.s.pktcnt)
        usbc_hctsiz.s.pktcnt = 1;

    __cvmx_usb_write_csr32(usb, CVMX_USBCX_HCTSIZX(channel, usb->index), usbc_hctsiz.u32);
    CVMX_USB_RETURN_NOTHING();
}


/**
 * @INTERNAL
 * Start a channel to perform the pipe's head transaction
 *
 * @param usb     USB device state populated by
 *                cvmx_usb_initialize().
 * @param channel Channel to setup
 * @param pipe    Pipe to start
 */
static void __cvmx_usb_start_channel(cvmx_usb_internal_state_t *usb,
                                     int channel,
                                     cvmx_usb_pipe_t *pipe)
{
    cvmx_usb_transaction_t *transaction = pipe->head;
    cvmx_usbcx_hfnum_t usbc_hfnum;

    CVMX_USB_LOG_CALLED();
    CVMX_USB_LOG_PARAM("%p", usb);
    CVMX_USB_LOG_PARAM("%d", channel);
    CVMX_USB_LOG_PARAM("%p", pipe);

    if (cvmx_unlikely((usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEBUG_TRANSFERS) ||
        (pipe->flags & CVMX_USB_PIPE_FLAGS_DEBUG_TRANSFERS)))
        cvmx_dprintf("%s: Channel %d started. Pipe %d transaction %d stage %d\n",
                     __FUNCTION__, channel, __cvmx_usb_get_pipe_handle(usb, pipe),
                     __cvmx_usb_get_submit_handle(usb, transaction),
                     transaction->stage);

    /* Make sure all writes to the DMA region get flushed */
    CVMX_SYNCW;

    /* Read the current frame number for use with split, INTERRUPT,  and ISO
        transactions */
    usbc_hfnum.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_HFNUM(usb->index));

    /* Attach the channel to the pipe */
    usb->pipe_for_channel[channel] = pipe;
    pipe->channel = channel;
    pipe->flags |= __CVMX_USB_PIPE_FLAGS_SCHEDULED;

    /* Mark this channel as in use */
    usb->idle_hardware_channels &= ~(1<<channel);

    /* Enable the channel interrupt bits */
    {
        cvmx_usbcx_hcintx_t usbc_hcint;

        /* Clear all channel status bits */
        usbc_hcint.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_HCINTX(channel, usb->index));
        __cvmx_usb_write_csr32(usb, CVMX_USBCX_HCINTX(channel, usb->index), usbc_hcint.u32);
    }

    /* Setup the locations the DMA engines use  */
    {
        uint64_t dma_address = transaction->buffer + transaction->actual_bytes;
        if (transaction->type == CVMX_USB_TRANSFER_ISOCHRONOUS)
            dma_address = transaction->buffer + transaction->iso_packets[0].offset + transaction->actual_bytes;
        __cvmx_usb_write_csr64(usb, CVMX_USBNX_DMA0_OUTB_CHN0(usb->index) + channel*8, dma_address);
        __cvmx_usb_write_csr64(usb, CVMX_USBNX_DMA0_INB_CHN0(usb->index) + channel*8, dma_address);
    }

    /* Setup both the size of the transfer and the SPLIT characteristics */
    {
        cvmx_usbcx_hcspltx_t usbc_hcsplt = {.u32 = 0};
        cvmx_usbcx_hctsizx_t usbc_hctsiz = {.u32 = 0};
        int bytes_to_transfer = transaction->buffer_length - transaction->actual_bytes;

        /* ISOCHRONOUS transactions store each individual transfer size in the
            packet structure, not the global buffer_length */
        if (transaction->type == CVMX_USB_TRANSFER_ISOCHRONOUS)
            bytes_to_transfer = transaction->iso_packets[0].length - transaction->actual_bytes;

        /* We need to do split transactions when we are talking to non high
            speed devices that are behind a high speed hub */
        if (__cvmx_usb_pipe_needs_split(usb, pipe))
        {
            /* On the start split phase (stage is even) record the frame number we
                will need to send the split complete. We only store the lower two bits
                since the time ahead can only be two frames */
            if ((transaction->stage&1) == 0)
            {
                if (transaction->type == CVMX_USB_TRANSFER_BULK)
                    pipe->split_sc_frame = (usbc_hfnum.s.frnum + 1) & 0x7f;
                else
                    pipe->split_sc_frame = (usbc_hfnum.s.frnum + 2) & 0x7f;
            }
            else
                pipe->split_sc_frame = -1;

            usbc_hcsplt.s.spltena = 1;
            usbc_hcsplt.s.hubaddr = pipe->hub_device_addr;
            usbc_hcsplt.s.prtaddr = pipe->hub_port;
            usbc_hcsplt.s.compsplt = (transaction->stage == CVMX_USB_STAGE_NON_CONTROL_SPLIT_COMPLETE);

            /* SPLIT transactions can only ever transmit one data packet so
                limit the transfer size to the max packet size */
            if (bytes_to_transfer > pipe->max_packet)
                bytes_to_transfer = pipe->max_packet;

            /* ISOCHRONOUS OUT splits are unique in that they limit
                data transfers to 188 byte chunks representing the
                begin/middle/end of the data or all */
            if (!usbc_hcsplt.s.compsplt &&
                (pipe->transfer_dir == CVMX_USB_DIRECTION_OUT) &&
                (pipe->transfer_type == CVMX_USB_TRANSFER_ISOCHRONOUS))
            {
                /* See if we've started this tranfer and sent data */
                if (transaction->actual_bytes == 0)
                {
                    /* Nothing sent yet, this is either a begin or the
                        entire payload */
                    if (bytes_to_transfer <= 188)
                        usbc_hcsplt.s.xactpos = 3; /* Entire payload in one go */
                    else
                        usbc_hcsplt.s.xactpos = 2; /* First part of payload */
                }
                else
                {
                    /* Continuing the previous data, we must either be
                        in the middle or at the end */
                    if (bytes_to_transfer <= 188)
                        usbc_hcsplt.s.xactpos = 1; /* End of payload */
                    else
                        usbc_hcsplt.s.xactpos = 0; /* Middle of payload */
                }
                /* Again, the transfer size is limited to 188 bytes */
                if (bytes_to_transfer > 188)
                    bytes_to_transfer = 188;
            }
        }

        usbc_hctsiz.s.xfersize = bytes_to_transfer;
        usbc_hctsiz.s.pktcnt = (bytes_to_transfer + pipe->max_packet - 1) / pipe->max_packet;
        if (!usbc_hctsiz.s.pktcnt)
            usbc_hctsiz.s.pktcnt = 1;

        /* Update the DATA0/DATA1 toggle */
        usbc_hctsiz.s.pid = __cvmx_usb_get_data_pid(pipe);
        /* High speed pipes may need a hardware ping before they start */
        if (pipe->flags & __CVMX_USB_PIPE_FLAGS_NEED_PING)
            usbc_hctsiz.s.dopng = 1;

        __cvmx_usb_write_csr32(usb, CVMX_USBCX_HCSPLTX(channel, usb->index), usbc_hcsplt.u32);
        __cvmx_usb_write_csr32(usb, CVMX_USBCX_HCTSIZX(channel, usb->index), usbc_hctsiz.u32);
    }

    /* Setup the Host Channel Characteristics Register */
    {
        cvmx_usbcx_hccharx_t usbc_hcchar = {.u32 = 0};

        /* Make all transfers start on the next frame and not this one. This
            way the time we spend processing doesn't affect USB timing */
        usbc_hcchar.s.oddfrm = !(usbc_hfnum.s.frnum&1);

        /* Set the number of back to back packets allowed by this endpoint.
            Split transactions interpret "ec" as the number of immediate
            retries of failure. These retries happen too quickly, so we
            disable these entirely for splits */
        if (__cvmx_usb_pipe_needs_split(usb, pipe))
            usbc_hcchar.s.ec = 1;
        else if (pipe->multi_count < 1)
            usbc_hcchar.s.ec = 1;
        else if (pipe->multi_count > 3)
            usbc_hcchar.s.ec = 3;
        else
            usbc_hcchar.s.ec = pipe->multi_count;

        /* Set the rest of the endpoint specific settings */
        usbc_hcchar.s.devaddr = pipe->device_addr;
        usbc_hcchar.s.eptype = transaction->type;
        usbc_hcchar.s.lspddev = (pipe->device_speed == CVMX_USB_SPEED_LOW);
        usbc_hcchar.s.epdir = pipe->transfer_dir;
        usbc_hcchar.s.epnum = pipe->endpoint_num;
        usbc_hcchar.s.mps = pipe->max_packet;
        __cvmx_usb_write_csr32(usb, CVMX_USBCX_HCCHARX(channel, usb->index), usbc_hcchar.u32);
    }

    /* Do transaction type specific fixups as needed */
    switch (transaction->type)
    {
        case CVMX_USB_TRANSFER_CONTROL:
            __cvmx_usb_start_channel_control(usb, channel, pipe);
            break;
        case CVMX_USB_TRANSFER_BULK:
        case CVMX_USB_TRANSFER_INTERRUPT:
            break;
        case CVMX_USB_TRANSFER_ISOCHRONOUS:
            if (!__cvmx_usb_pipe_needs_split(usb, pipe))
            {
                /* ISO transactions require differnet PIDs depending on direction
                    and how many packets are needed */
                if (pipe->transfer_dir == CVMX_USB_DIRECTION_OUT)
                {
                    if (pipe->multi_count < 2) /* Need DATA0 */
                        USB_SET_FIELD32(CVMX_USBCX_HCTSIZX(channel, usb->index), cvmx_usbcx_hctsizx_t, pid, 0);
                    else /* Need MDATA */
                        USB_SET_FIELD32(CVMX_USBCX_HCTSIZX(channel, usb->index), cvmx_usbcx_hctsizx_t, pid, 3);
                }
            }
            break;
    }
    {
        cvmx_usbcx_hctsizx_t usbc_hctsiz = {.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_HCTSIZX(channel, usb->index))};
        transaction->xfersize = usbc_hctsiz.s.xfersize;
        transaction->pktcnt = usbc_hctsiz.s.pktcnt;
    }
    USB_SET_FIELD32(CVMX_USBCX_HCCHARX(channel, usb->index), cvmx_usbcx_hccharx_t, chena, 1);
    CVMX_USB_RETURN_NOTHING();
}


/**
 * @INTERNAL
 * Find a pipe that is ready to be scheduled to hardware.
 *
 * @param list       Pipe list to search
 * @param usbc_hfnum Current USB frame number
 * @param current_cycle
 *                   Cycle counter to use as a time reference.
 *
 * @return Pipe or NULL if none are ready
 */
static cvmx_usb_pipe_t *__cvmx_usb_find_ready_pipe(cvmx_usb_pipe_list_t *list, cvmx_usbcx_hfnum_t usbc_hfnum, uint64_t current_cycle)
{
    cvmx_usb_pipe_t *pipe = list->head;
    while (pipe)
    {
        if (!(pipe->flags & __CVMX_USB_PIPE_FLAGS_SCHEDULED) && pipe->head &&
            (pipe->next_tx_cycle <= current_cycle) &&
            ((pipe->split_sc_frame == -1) || ((((int)usbc_hfnum.s.frnum - (int)pipe->split_sc_frame) & 0x7f) < 0x40)))
        {
            CVMX_PREFETCH(pipe, 128);
            CVMX_PREFETCH(pipe->head, 0);
            return pipe;
        }
        pipe = pipe->next;
    }
    return NULL;
}


/**
 * @INTERNAL
 * Called whenever a pipe might need to be scheduled to the
 * hardware.
 *
 * @param usb    USB device state populated by
 *               cvmx_usb_initialize().
 * @param is_sof True if this schedule was called on a SOF interrupt.
 */
static void __cvmx_usb_schedule(cvmx_usb_internal_state_t *usb, int is_sof)
{
    int channel;
    cvmx_usb_pipe_t *pipe;
    cvmx_usbcx_hfnum_t usbc_hfnum;
    uint64_t current_cycle = cvmx_read64_uint64(CVMX_IPD_CLK_COUNT);

    CVMX_USB_LOG_CALLED();
    CVMX_USB_LOG_PARAM("%p", usb);

    usbc_hfnum.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_HFNUM(usb->index));

    while (usb->idle_hardware_channels)
    {
        /* Find an idle channel */
        CVMX_CLZ(channel, usb->idle_hardware_channels);
        channel = 31 - channel;
        if (cvmx_unlikely(channel > 7))
        {
            if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEBUG_INFO))
                cvmx_dprintf("%s: Idle hardware channels has a channel higher than 7. This is wrong\n", __FUNCTION__);
            break;
        }

        /* Find a pipe needing service */
        pipe = NULL;
        if (is_sof)
        {
            /* Only process periodic pipes on SOF interrupts. This way we are
                sure that the periodic data is sent in the beginning of the
                frame */
            pipe = __cvmx_usb_find_ready_pipe(usb->active_pipes + CVMX_USB_TRANSFER_ISOCHRONOUS, usbc_hfnum, current_cycle);
            if (cvmx_likely(!pipe))
                pipe = __cvmx_usb_find_ready_pipe(usb->active_pipes + CVMX_USB_TRANSFER_INTERRUPT, usbc_hfnum, current_cycle);
        }
        if (cvmx_likely(!pipe))
        {
            pipe = __cvmx_usb_find_ready_pipe(usb->active_pipes + CVMX_USB_TRANSFER_CONTROL, usbc_hfnum, current_cycle);
            if (cvmx_likely(!pipe))
                pipe = __cvmx_usb_find_ready_pipe(usb->active_pipes + CVMX_USB_TRANSFER_BULK, usbc_hfnum, current_cycle);
        }
        if (!pipe)
            break;

        CVMX_USB_LOG_PARAM("%d", channel);
        CVMX_USB_LOG_PARAM("%p", pipe);

        if (cvmx_unlikely((usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEBUG_TRANSFERS) ||
            (pipe->flags & CVMX_USB_PIPE_FLAGS_DEBUG_TRANSFERS)))
        {
            cvmx_usb_transaction_t *transaction = pipe->head;
            const cvmx_usb_control_header_t *header = (transaction->control_header) ? cvmx_phys_to_ptr(transaction->control_header) : NULL;
            const char *dir = (pipe->transfer_dir == CVMX_USB_DIRECTION_IN) ? "IN" : "OUT";
            const char *type;
            switch (pipe->transfer_type)
            {
                case CVMX_USB_TRANSFER_CONTROL:
                    type = "SETUP";
                    dir = (header->s.request_type & 0x80) ? "IN" : "OUT";
                    break;
                case CVMX_USB_TRANSFER_ISOCHRONOUS:
                    type = "ISOCHRONOUS";
                    break;
                case CVMX_USB_TRANSFER_BULK:
                    type = "BULK";
                    break;
                default: /* CVMX_USB_TRANSFER_INTERRUPT */
                    type = "INTERRUPT";
                    break;
            }
            cvmx_dprintf("%s: Starting pipe %d, transaction %d on channel %d. %s %s len=%d header=0x%llx\n",
                         __FUNCTION__, __cvmx_usb_get_pipe_handle(usb, pipe),
                         __cvmx_usb_get_submit_handle(usb, transaction),
                         channel, type, dir,
                         transaction->buffer_length,
                         (header) ? (unsigned long long)header->u64 : 0ull);
        }
        __cvmx_usb_start_channel(usb, channel, pipe);
    }
    CVMX_USB_RETURN_NOTHING();
}


/**
 * @INTERNAL
 * Call a user's callback for a specific reason.
 *
 * @param usb    USB device state populated by
 *               cvmx_usb_initialize().
 * @param pipe   Pipe the callback is for or NULL
 * @param transaction
 *               Transaction the callback is for or NULL
 * @param reason Reason this callback is being called
 * @param complete_code
 *               Completion code for the transaction, if any
 */
static void __cvmx_usb_perform_callback(cvmx_usb_internal_state_t *usb,
                                        cvmx_usb_pipe_t *pipe,
                                        cvmx_usb_transaction_t *transaction,
                                        cvmx_usb_callback_t reason,
                                        cvmx_usb_complete_t complete_code)
{
    cvmx_usb_callback_func_t callback = usb->callback[reason];
    void *user_data = usb->callback_data[reason];
    int submit_handle = -1;
    int pipe_handle = -1;
    int bytes_transferred = 0;

    if (pipe)
        pipe_handle = __cvmx_usb_get_pipe_handle(usb, pipe);

    if (transaction)
    {
        submit_handle = __cvmx_usb_get_submit_handle(usb, transaction);
        bytes_transferred = transaction->actual_bytes;
        /* Transactions are allowed to override the default callback */
        if ((reason == CVMX_USB_CALLBACK_TRANSFER_COMPLETE) && transaction->callback)
        {
            callback = transaction->callback;
            user_data = transaction->callback_data;
        }
    }

    if (!callback)
        return;

    if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEBUG_CALLBACKS))
        cvmx_dprintf("%*s%s: calling callback %p(usb=%p, complete_code=%s, "
                     "pipe_handle=%d, submit_handle=%d, bytes_transferred=%d, user_data=%p);\n",
                     2*usb->indent, "", __FUNCTION__, callback, usb,
                     __cvmx_usb_complete_to_string(complete_code),
                     pipe_handle, submit_handle, bytes_transferred, user_data);

    callback((cvmx_usb_state_t *)usb, reason, complete_code, pipe_handle, submit_handle,
             bytes_transferred, user_data);

    if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEBUG_CALLBACKS))
        cvmx_dprintf("%*s%s: callback %p complete\n", 2*usb->indent, "",
                      __FUNCTION__, callback);
}


/**
 * @INTERNAL
 * Signal the completion of a transaction and free it. The
 * transaction will be removed from the pipe transaction list.
 *
 * @param usb    USB device state populated by
 *               cvmx_usb_initialize().
 * @param pipe   Pipe the transaction is on
 * @param transaction
 *               Transaction that completed
 * @param complete_code
 *               Completion code
 */
static void __cvmx_usb_perform_complete(cvmx_usb_internal_state_t * usb,
                                        cvmx_usb_pipe_t *pipe,
                                        cvmx_usb_transaction_t *transaction,
                                        cvmx_usb_complete_t complete_code)
{
    CVMX_USB_LOG_CALLED();
    CVMX_USB_LOG_PARAM("%p", usb);
    CVMX_USB_LOG_PARAM("%p", pipe);
    CVMX_USB_LOG_PARAM("%p", transaction);
    CVMX_USB_LOG_PARAM("%d", complete_code);

    /* Isochronous transactions need extra processing as they might not be done
        after a single data transfer */
    if (cvmx_unlikely(transaction->type == CVMX_USB_TRANSFER_ISOCHRONOUS))
    {
        /* Update the number of bytes transfered in this ISO packet */
        transaction->iso_packets[0].length = transaction->actual_bytes;
        transaction->iso_packets[0].status = complete_code;

        /* If there are more ISOs pending and we suceeded, schedule the next
            one */
        if ((transaction->iso_number_packets > 1) && (complete_code == CVMX_USB_COMPLETE_SUCCESS))
        {
            transaction->actual_bytes = 0;      /* No bytes transfered for this packet as of yet */
            transaction->iso_number_packets--;  /* One less ISO waiting to transfer */
            transaction->iso_packets++;         /* Increment to the next location in our packet array */
            transaction->stage = CVMX_USB_STAGE_NON_CONTROL;
            goto done;
        }
    }

    /* Remove the transaction from the pipe list */
    if (transaction->next)
        transaction->next->prev = transaction->prev;
    else
        pipe->tail = transaction->prev;
    if (transaction->prev)
        transaction->prev->next = transaction->next;
    else
        pipe->head = transaction->next;
    if (!pipe->head)
    {
        __cvmx_usb_remove_pipe(usb->active_pipes + pipe->transfer_type, pipe);
        __cvmx_usb_append_pipe(&usb->idle_pipes, pipe);

    }
    __cvmx_usb_perform_callback(usb, pipe, transaction,
                                CVMX_USB_CALLBACK_TRANSFER_COMPLETE,
                                complete_code);
    __cvmx_usb_free_transaction(usb, transaction);
    /* Disable SOF interrupts if we don't have any pending transactions */
    usb->active_transactions--;
    if (usb->active_transactions == 0)
        USB_SET_FIELD32(CVMX_USBCX_GINTMSK(usb->index), cvmx_usbcx_gintmsk_t, sofmsk, 0);
done:
    CVMX_USB_RETURN_NOTHING();
}


/**
 * @INTERNAL
 * Submit a usb transaction to a pipe. Called for all types
 * of transactions.
 *
 * @param usb
 * @param pipe_handle
 *                  Which pipe to submit to. Will be validated in this function.
 * @param type      Transaction type
 * @param flags     Flags for the transaction
 * @param buffer    User buffer for the transaction
 * @param buffer_length
 *                  User buffer's length in bytes
 * @param control_header
 *                  For control transactions, the 8 byte standard header
 * @param iso_start_frame
 *                  For ISO transactiosn, the start frame
 * @param iso_number_packets
 *                  For ISO, the number of packet in the transaction.
 * @param iso_packets
 *                  A description of each ISO packet
 * @param callback  User callback to call when the transaction completes
 * @param user_data User's data for the callback
 *
 * @return Submit handle or negative on failure. Matches the result
 *         in the external API.
 */
static int __cvmx_usb_submit_transaction(cvmx_usb_internal_state_t *usb,
                                         int pipe_handle,
                                         cvmx_usb_transfer_t type,
                                         int flags,
                                         uint64_t buffer,
                                         int buffer_length,
                                         uint64_t control_header,
                                         int iso_start_frame,
                                         int iso_number_packets,
                                         cvmx_usb_iso_packet_t *iso_packets,
                                         cvmx_usb_callback_func_t callback,
                                         void *user_data)
{
    int submit_handle;
    cvmx_usb_transaction_t *transaction;
    cvmx_usb_pipe_t *pipe = usb->pipe + pipe_handle;

    CVMX_USB_LOG_CALLED();
    if (cvmx_unlikely((pipe_handle < 0) || (pipe_handle >= MAX_PIPES)))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    /* Fail if the pipe isn't open */
    if (cvmx_unlikely((pipe->flags & __CVMX_USB_PIPE_FLAGS_OPEN) == 0))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely(pipe->transfer_type != type))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);

    transaction = __cvmx_usb_alloc_transaction(usb);
    if (cvmx_unlikely(!transaction))
        CVMX_USB_RETURN(CVMX_USB_NO_MEMORY);

    /* Enable SOF interrupts now that we have pending transactions */
    if (usb->active_transactions == 0)
        USB_SET_FIELD32(CVMX_USBCX_GINTMSK(usb->index), cvmx_usbcx_gintmsk_t, sofmsk, 1);
    usb->active_transactions++;

    transaction->type = type;
    transaction->flags |= flags;
    transaction->buffer = buffer;
    transaction->buffer_length = buffer_length;
    transaction->control_header = control_header;
    transaction->iso_start_frame = iso_start_frame; // FIXME: This is not used, implement it
    transaction->iso_number_packets = iso_number_packets;
    transaction->iso_packets = iso_packets;
    transaction->callback = callback;
    transaction->callback_data = user_data;
    if (transaction->type == CVMX_USB_TRANSFER_CONTROL)
        transaction->stage = CVMX_USB_STAGE_SETUP;
    else
        transaction->stage = CVMX_USB_STAGE_NON_CONTROL;

    transaction->next = NULL;
    if (pipe->tail)
    {
        transaction->prev = pipe->tail;
        transaction->prev->next = transaction;
    }
    else
    {
        transaction->prev = NULL;
        pipe->head = transaction;
        __cvmx_usb_remove_pipe(&usb->idle_pipes, pipe);
        __cvmx_usb_append_pipe(usb->active_pipes + pipe->transfer_type, pipe);
    }
    pipe->tail = transaction;

    submit_handle = __cvmx_usb_get_submit_handle(usb, transaction);

    /* We may need to schedule the pipe if this was the head of the pipe */
    if (!transaction->prev)
        __cvmx_usb_schedule(usb, 0);

    CVMX_USB_RETURN(submit_handle);
}


/**
 * Call to submit a USB Bulk transfer to a pipe.
 *
 * @param state     USB device state populated by
 *                  cvmx_usb_initialize().
 * @param pipe_handle
 *                  Handle to the pipe for the transfer.
 * @param buffer    Physical address of the data buffer in
 *                  memory. Note that this is NOT A POINTER, but
 *                  the full 64bit physical address of the
 *                  buffer. This may be zero if buffer_length is
 *                  zero.
 * @param buffer_length
 *                  Length of buffer in bytes.
 * @param callback  Function to call when this transaction
 *                  completes. If the return value of this
 *                  function isn't an error, then this function
 *                  is guaranteed to be called when the
 *                  transaction completes. If this parameter is
 *                  NULL, then the generic callback registered
 *                  through cvmx_usb_register_callback is
 *                  called. If both are NULL, then there is no
 *                  way to know when a transaction completes.
 * @param user_data User supplied data returned when the
 *                  callback is called. This is only used if
 *                  callback in not NULL.
 *
 * @return A submitted transaction handle or negative on
 *         failure. Negative values are failure codes from
 *         cvmx_usb_status_t.
 */
int cvmx_usb_submit_bulk(cvmx_usb_state_t *state, int pipe_handle,
                                uint64_t buffer, int buffer_length,
                                cvmx_usb_callback_func_t callback,
                                void *user_data)
{
    int submit_handle;
    cvmx_usb_internal_state_t *usb = (cvmx_usb_internal_state_t*)state;

    CVMX_USB_LOG_CALLED();
    CVMX_USB_LOG_PARAM("%p", state);
    CVMX_USB_LOG_PARAM("%d", pipe_handle);
    CVMX_USB_LOG_PARAM("0x%llx", (unsigned long long)buffer);
    CVMX_USB_LOG_PARAM("%d", buffer_length);

    /* Pipe handle checking is done later in a common place */
    if (cvmx_unlikely(!buffer))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely(buffer_length < 0))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEVICE_MODE))
        CVMX_USB_RETURN(CVMX_USB_INCORRECT_MODE);

    submit_handle = __cvmx_usb_submit_transaction(usb, pipe_handle,
                                         CVMX_USB_TRANSFER_BULK,
                                         0, /* flags */
                                         buffer,
                                         buffer_length,
                                         0, /* control_header */
                                         0, /* iso_start_frame */
                                         0, /* iso_number_packets */
                                         NULL, /* iso_packets */
                                         callback,
                                         user_data);
    CVMX_USB_RETURN(submit_handle);
}


/**
 * Call to submit a USB Interrupt transfer to a pipe.
 *
 * @param state     USB device state populated by
 *                  cvmx_usb_initialize().
 * @param pipe_handle
 *                  Handle to the pipe for the transfer.
 * @param buffer    Physical address of the data buffer in
 *                  memory. Note that this is NOT A POINTER, but
 *                  the full 64bit physical address of the
 *                  buffer. This may be zero if buffer_length is
 *                  zero.
 * @param buffer_length
 *                  Length of buffer in bytes.
 * @param callback  Function to call when this transaction
 *                  completes. If the return value of this
 *                  function isn't an error, then this function
 *                  is guaranteed to be called when the
 *                  transaction completes. If this parameter is
 *                  NULL, then the generic callback registered
 *                  through cvmx_usb_register_callback is
 *                  called. If both are NULL, then there is no
 *                  way to know when a transaction completes.
 * @param user_data User supplied data returned when the
 *                  callback is called. This is only used if
 *                  callback in not NULL.
 *
 * @return A submitted transaction handle or negative on
 *         failure. Negative values are failure codes from
 *         cvmx_usb_status_t.
 */
int cvmx_usb_submit_interrupt(cvmx_usb_state_t *state, int pipe_handle,
                              uint64_t buffer, int buffer_length,
                              cvmx_usb_callback_func_t callback,
                              void *user_data)
{
    int submit_handle;
    cvmx_usb_internal_state_t *usb = (cvmx_usb_internal_state_t*)state;

    CVMX_USB_LOG_CALLED();
    CVMX_USB_LOG_PARAM("%p", state);
    CVMX_USB_LOG_PARAM("%d", pipe_handle);
    CVMX_USB_LOG_PARAM("0x%llx", (unsigned long long)buffer);
    CVMX_USB_LOG_PARAM("%d", buffer_length);

    /* Pipe handle checking is done later in a common place */
    if (cvmx_unlikely(!buffer))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely(buffer_length < 0))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEVICE_MODE))
        CVMX_USB_RETURN(CVMX_USB_INCORRECT_MODE);

    submit_handle = __cvmx_usb_submit_transaction(usb, pipe_handle,
                                         CVMX_USB_TRANSFER_INTERRUPT,
                                         0, /* flags */
                                         buffer,
                                         buffer_length,
                                         0, /* control_header */
                                         0, /* iso_start_frame */
                                         0, /* iso_number_packets */
                                         NULL, /* iso_packets */
                                         callback,
                                         user_data);
    CVMX_USB_RETURN(submit_handle);
}


/**
 * Call to submit a USB Control transfer to a pipe.
 *
 * @param state     USB device state populated by
 *                  cvmx_usb_initialize().
 * @param pipe_handle
 *                  Handle to the pipe for the transfer.
 * @param control_header
 *                  USB 8 byte control header physical address.
 *                  Note that this is NOT A POINTER, but the
 *                  full 64bit physical address of the buffer.
 * @param buffer    Physical address of the data buffer in
 *                  memory. Note that this is NOT A POINTER, but
 *                  the full 64bit physical address of the
 *                  buffer. This may be zero if buffer_length is
 *                  zero.
 * @param buffer_length
 *                  Length of buffer in bytes.
 * @param callback  Function to call when this transaction
 *                  completes. If the return value of this
 *                  function isn't an error, then this function
 *                  is guaranteed to be called when the
 *                  transaction completes. If this parameter is
 *                  NULL, then the generic callback registered
 *                  through cvmx_usb_register_callback is
 *                  called. If both are NULL, then there is no
 *                  way to know when a transaction completes.
 * @param user_data User supplied data returned when the
 *                  callback is called. This is only used if
 *                  callback in not NULL.
 *
 * @return A submitted transaction handle or negative on
 *         failure. Negative values are failure codes from
 *         cvmx_usb_status_t.
 */
int cvmx_usb_submit_control(cvmx_usb_state_t *state, int pipe_handle,
                            uint64_t control_header,
                            uint64_t buffer, int buffer_length,
                            cvmx_usb_callback_func_t callback,
                            void *user_data)
{
    int submit_handle;
    cvmx_usb_internal_state_t *usb = (cvmx_usb_internal_state_t*)state;
    cvmx_usb_control_header_t *header = cvmx_phys_to_ptr(control_header);

    CVMX_USB_LOG_CALLED();
    CVMX_USB_LOG_PARAM("%p", state);
    CVMX_USB_LOG_PARAM("%d", pipe_handle);
    CVMX_USB_LOG_PARAM("0x%llx", (unsigned long long)control_header);
    CVMX_USB_LOG_PARAM("0x%llx", (unsigned long long)buffer);
    CVMX_USB_LOG_PARAM("%d", buffer_length);

    /* Pipe handle checking is done later in a common place */
    if (cvmx_unlikely(!control_header))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    /* Some drivers send a buffer with a zero length. God only knows why */
    if (cvmx_unlikely(buffer && (buffer_length < 0)))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely(!buffer && (buffer_length != 0)))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEVICE_MODE))
        CVMX_USB_RETURN(CVMX_USB_INCORRECT_MODE);
    if ((header->s.request_type & 0x80) == 0)
        buffer_length = cvmx_le16_to_cpu(header->s.length);

    submit_handle = __cvmx_usb_submit_transaction(usb, pipe_handle,
                                         CVMX_USB_TRANSFER_CONTROL,
                                         0, /* flags */
                                         buffer,
                                         buffer_length,
                                         control_header,
                                         0, /* iso_start_frame */
                                         0, /* iso_number_packets */
                                         NULL, /* iso_packets */
                                         callback,
                                         user_data);
    CVMX_USB_RETURN(submit_handle);
}


/**
 * Call to submit a USB Isochronous transfer to a pipe.
 *
 * @param state     USB device state populated by
 *                  cvmx_usb_initialize().
 * @param pipe_handle
 *                  Handle to the pipe for the transfer.
 * @param start_frame
 *                  Number of frames into the future to schedule
 *                  this transaction.
 * @param flags     Flags to control the transfer. See
 *                  cvmx_usb_isochronous_flags_t for the flag
 *                  definitions.
 * @param number_packets
 *                  Number of sequential packets to transfer.
 *                  "packets" is a pointer to an array of this
 *                  many packet structures.
 * @param packets   Description of each transfer packet as
 *                  defined by cvmx_usb_iso_packet_t. The array
 *                  pointed to here must stay valid until the
 *                  complete callback is called.
 * @param buffer    Physical address of the data buffer in
 *                  memory. Note that this is NOT A POINTER, but
 *                  the full 64bit physical address of the
 *                  buffer. This may be zero if buffer_length is
 *                  zero.
 * @param buffer_length
 *                  Length of buffer in bytes.
 * @param callback  Function to call when this transaction
 *                  completes. If the return value of this
 *                  function isn't an error, then this function
 *                  is guaranteed to be called when the
 *                  transaction completes. If this parameter is
 *                  NULL, then the generic callback registered
 *                  through cvmx_usb_register_callback is
 *                  called. If both are NULL, then there is no
 *                  way to know when a transaction completes.
 * @param user_data User supplied data returned when the
 *                  callback is called. This is only used if
 *                  callback in not NULL.
 *
 * @return A submitted transaction handle or negative on
 *         failure. Negative values are failure codes from
 *         cvmx_usb_status_t.
 */
int cvmx_usb_submit_isochronous(cvmx_usb_state_t *state, int pipe_handle,
                                int start_frame, int flags,
                                int number_packets,
                                cvmx_usb_iso_packet_t packets[],
                                uint64_t buffer, int buffer_length,
                                cvmx_usb_callback_func_t callback,
                                void *user_data)
{
    int submit_handle;
    cvmx_usb_internal_state_t *usb = (cvmx_usb_internal_state_t*)state;

    CVMX_USB_LOG_CALLED();
    CVMX_USB_LOG_PARAM("%p", state);
    CVMX_USB_LOG_PARAM("%d", pipe_handle);
    CVMX_USB_LOG_PARAM("%d", start_frame);
    CVMX_USB_LOG_PARAM("0x%x", flags);
    CVMX_USB_LOG_PARAM("%d", number_packets);
    CVMX_USB_LOG_PARAM("%p", packets);
    CVMX_USB_LOG_PARAM("0x%llx", (unsigned long long)buffer);
    CVMX_USB_LOG_PARAM("%d", buffer_length);

    /* Pipe handle checking is done later in a common place */
    if (cvmx_unlikely(start_frame < 0))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely(flags & ~(CVMX_USB_ISOCHRONOUS_FLAGS_ALLOW_SHORT | CVMX_USB_ISOCHRONOUS_FLAGS_ASAP)))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely(number_packets < 1))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely(!packets))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely(!buffer))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely(buffer_length < 0))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEVICE_MODE))
        CVMX_USB_RETURN(CVMX_USB_INCORRECT_MODE);

    submit_handle = __cvmx_usb_submit_transaction(usb, pipe_handle,
                                         CVMX_USB_TRANSFER_ISOCHRONOUS,
                                         flags,
                                         buffer,
                                         buffer_length,
                                         0, /* control_header */
                                         start_frame,
                                         number_packets,
                                         packets,
                                         callback,
                                         user_data);
    CVMX_USB_RETURN(submit_handle);
}


/**
 * Cancel one outstanding request in a pipe. Canceling a request
 * can fail if the transaction has already completed before cancel
 * is called. Even after a successful cancel call, it may take
 * a frame or two for the cvmx_usb_poll() function to call the
 * associated callback.
 *
 * @param state  USB device state populated by
 *               cvmx_usb_initialize().
 * @param pipe_handle
 *               Pipe handle to cancel requests in.
 * @param submit_handle
 *               Handle to transaction to cancel, returned by the submit function.
 *
 * @return CVMX_USB_SUCCESS or a negative error code defined in
 *         cvmx_usb_status_t.
 */
cvmx_usb_status_t cvmx_usb_cancel(cvmx_usb_state_t *state, int pipe_handle,
                                  int submit_handle)
{
    cvmx_usb_transaction_t *transaction;
    cvmx_usb_internal_state_t *usb = (cvmx_usb_internal_state_t*)state;
    cvmx_usb_pipe_t *pipe = usb->pipe + pipe_handle;

    CVMX_USB_LOG_CALLED();
    CVMX_USB_LOG_PARAM("%p", state);
    CVMX_USB_LOG_PARAM("%d", pipe_handle);
    CVMX_USB_LOG_PARAM("%d", submit_handle);

    if (cvmx_unlikely((pipe_handle < 0) || (pipe_handle >= MAX_PIPES)))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely((submit_handle < 0) || (submit_handle >= MAX_TRANSACTIONS)))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEVICE_MODE))
        CVMX_USB_RETURN(CVMX_USB_INCORRECT_MODE);

    /* Fail if the pipe isn't open */
    if (cvmx_unlikely((pipe->flags & __CVMX_USB_PIPE_FLAGS_OPEN) == 0))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);

    transaction = usb->transaction + submit_handle;

    /* Fail if this transaction already completed */
    if (cvmx_unlikely((transaction->flags & __CVMX_USB_TRANSACTION_FLAGS_IN_USE) == 0))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);

    /* If the transaction is the HEAD of the queue and scheduled. We need to
        treat it special */
    if ((pipe->head == transaction) &&
        (pipe->flags & __CVMX_USB_PIPE_FLAGS_SCHEDULED))
    {
        cvmx_usbcx_hccharx_t usbc_hcchar;

        usb->pipe_for_channel[pipe->channel] = NULL;
        pipe->flags &= ~__CVMX_USB_PIPE_FLAGS_SCHEDULED;

        CVMX_SYNCW;

        usbc_hcchar.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_HCCHARX(pipe->channel, usb->index));
        /* If the channel isn't enabled then the transaction already completed */
        if (usbc_hcchar.s.chena)
        {
            usbc_hcchar.s.chdis = 1;
            __cvmx_usb_write_csr32(usb, CVMX_USBCX_HCCHARX(pipe->channel, usb->index), usbc_hcchar.u32);
        }
    }
    __cvmx_usb_perform_complete(usb, pipe, transaction, CVMX_USB_COMPLETE_CANCEL);
    CVMX_USB_RETURN(CVMX_USB_SUCCESS);
}


/**
 * Cancel all outstanding requests in a pipe. Logically all this
 * does is call cvmx_usb_cancel() in a loop.
 *
 * @param state  USB device state populated by
 *               cvmx_usb_initialize().
 * @param pipe_handle
 *               Pipe handle to cancel requests in.
 *
 * @return CVMX_USB_SUCCESS or a negative error code defined in
 *         cvmx_usb_status_t.
 */
cvmx_usb_status_t cvmx_usb_cancel_all(cvmx_usb_state_t *state, int pipe_handle)
{
    cvmx_usb_internal_state_t *usb = (cvmx_usb_internal_state_t*)state;
    cvmx_usb_pipe_t *pipe = usb->pipe + pipe_handle;

    CVMX_USB_LOG_CALLED();
    CVMX_USB_LOG_PARAM("%p", state);
    CVMX_USB_LOG_PARAM("%d", pipe_handle);
    if (cvmx_unlikely((pipe_handle < 0) || (pipe_handle >= MAX_PIPES)))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEVICE_MODE))
        CVMX_USB_RETURN(CVMX_USB_INCORRECT_MODE);

    /* Fail if the pipe isn't open */
    if (cvmx_unlikely((pipe->flags & __CVMX_USB_PIPE_FLAGS_OPEN) == 0))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);

    /* Simply loop through and attempt to cancel each transaction */
    while (pipe->head)
    {
        cvmx_usb_status_t result = cvmx_usb_cancel(state, pipe_handle,
            __cvmx_usb_get_submit_handle(usb, pipe->head));
        if (cvmx_unlikely(result != CVMX_USB_SUCCESS))
            CVMX_USB_RETURN(result);
    }
    CVMX_USB_RETURN(CVMX_USB_SUCCESS);
}


/**
 * Close a pipe created with cvmx_usb_open_pipe().
 *
 * @param state  USB device state populated by
 *               cvmx_usb_initialize().
 * @param pipe_handle
 *               Pipe handle to close.
 *
 * @return CVMX_USB_SUCCESS or a negative error code defined in
 *         cvmx_usb_status_t. CVMX_USB_BUSY is returned if the
 *         pipe has outstanding transfers.
 */
cvmx_usb_status_t cvmx_usb_close_pipe(cvmx_usb_state_t *state, int pipe_handle)
{
    cvmx_usb_internal_state_t *usb = (cvmx_usb_internal_state_t*)state;
    cvmx_usb_pipe_t *pipe = usb->pipe + pipe_handle;

    CVMX_USB_LOG_CALLED();
    CVMX_USB_LOG_PARAM("%p", state);
    CVMX_USB_LOG_PARAM("%d", pipe_handle);
    if (cvmx_unlikely((pipe_handle < 0) || (pipe_handle >= MAX_PIPES)))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEVICE_MODE))
        CVMX_USB_RETURN(CVMX_USB_INCORRECT_MODE);

    /* Fail if the pipe isn't open */
    if (cvmx_unlikely((pipe->flags & __CVMX_USB_PIPE_FLAGS_OPEN) == 0))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);

    /* Fail if the pipe has pending transactions */
    if (cvmx_unlikely(pipe->head))
        CVMX_USB_RETURN(CVMX_USB_BUSY);

    pipe->flags = 0;
    __cvmx_usb_remove_pipe(&usb->idle_pipes, pipe);
    __cvmx_usb_append_pipe(&usb->free_pipes, pipe);

    CVMX_USB_RETURN(CVMX_USB_SUCCESS);
}


/**
 * Register a function to be called when various USB events occur.
 *
 * @param state     USB device state populated by
 *                  cvmx_usb_initialize().
 * @param reason    Which event to register for.
 * @param callback  Function to call when the event occurs.
 * @param user_data User data parameter to the function.
 *
 * @return CVMX_USB_SUCCESS or a negative error code defined in
 *         cvmx_usb_status_t.
 */
cvmx_usb_status_t cvmx_usb_register_callback(cvmx_usb_state_t *state,
                                             cvmx_usb_callback_t reason,
                                             cvmx_usb_callback_func_t callback,
                                             void *user_data)
{
    cvmx_usb_internal_state_t *usb = (cvmx_usb_internal_state_t*)state;

    CVMX_USB_LOG_CALLED();
    CVMX_USB_LOG_PARAM("%p", state);
    CVMX_USB_LOG_PARAM("%d", reason);
    CVMX_USB_LOG_PARAM("%p", callback);
    CVMX_USB_LOG_PARAM("%p", user_data);
    if (cvmx_unlikely(reason >= __CVMX_USB_CALLBACK_END))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely(!callback))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);

    usb->callback[reason] = callback;
    usb->callback_data[reason] = user_data;

    CVMX_USB_RETURN(CVMX_USB_SUCCESS);
}


/**
 * Get the current USB protocol level frame number. The frame
 * number is always in the range of 0-0x7ff.
 *
 * @param state  USB device state populated by
 *               cvmx_usb_initialize().
 *
 * @return USB frame number
 */
int cvmx_usb_get_frame_number(cvmx_usb_state_t *state)
{
    int frame_number;
    cvmx_usb_internal_state_t *usb = (cvmx_usb_internal_state_t*)state;

    CVMX_USB_LOG_CALLED();
    CVMX_USB_LOG_PARAM("%p", state);

    if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEVICE_MODE))
    {
        cvmx_usbcx_dsts_t usbc_dsts;
        usbc_dsts.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_DSTS(usb->index));
        frame_number = usbc_dsts.s.soffn;
    }
    else
    {
        cvmx_usbcx_hfnum_t usbc_hfnum;
        usbc_hfnum.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_HFNUM(usb->index));
        frame_number = usbc_hfnum.s.frnum;
    }

    CVMX_USB_RETURN(frame_number);
}


/**
 * @INTERNAL
 * Poll a channel for status
 *
 * @param usb     USB device
 * @param channel Channel to poll
 *
 * @return Zero on success
 */
static int __cvmx_usb_poll_channel(cvmx_usb_internal_state_t *usb, int channel)
{
    cvmx_usbcx_hcintx_t usbc_hcint;
    cvmx_usbcx_hctsizx_t usbc_hctsiz;
    cvmx_usbcx_hccharx_t usbc_hcchar;
    cvmx_usb_pipe_t *pipe;
    cvmx_usb_transaction_t *transaction;
    int bytes_this_transfer;
    int bytes_in_last_packet;
    int packets_processed;
    int buffer_space_left;
    CVMX_USB_LOG_CALLED();
    CVMX_USB_LOG_PARAM("%p", usb);
    CVMX_USB_LOG_PARAM("%d", channel);

    /* Read the interrupt status bits for the channel */
    usbc_hcint.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_HCINTX(channel, usb->index));

    /* We ignore any interrupts where the channel hasn't halted yet. These
        should be impossible since we don't enable any interrupts except for
        channel halted */
    if (!usbc_hcint.s.chhltd)
        CVMX_USB_RETURN(0);

    /* Now that the channel has halted, clear all status bits before
        processing. This way we don't have any race conditions caused by the
        channel starting up and finishing before we clear the bits */
    __cvmx_usb_write_csr32(usb, CVMX_USBCX_HCINTX(channel, usb->index), usbc_hcint.u32);
    //cvmx_csr_db_decode(cvmx_get_proc_id(), CVMX_USBCX_HCINTX(channel, usb->index), usbc_hcint.u32);

    usb->idle_hardware_channels |= (1<<channel);

    /* Make sure this channel is tied to a valid pipe */
    pipe = usb->pipe_for_channel[channel];
    CVMX_PREFETCH(pipe, 0);
    CVMX_PREFETCH(pipe, 128);
    if (!pipe)
        CVMX_USB_RETURN(0);
    transaction = pipe->head;
    CVMX_PREFETCH0(transaction);

    /* Disconnect this pipe from the HW channel. Later the schedule function will
        figure out which pipe needs to go */
    usb->pipe_for_channel[channel] = NULL;
    pipe->flags &= ~__CVMX_USB_PIPE_FLAGS_SCHEDULED;

    /* Read the channel config info so we can figure out how much data
        transfered */
    usbc_hcchar.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_HCCHARX(channel, usb->index));
    usbc_hctsiz.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_HCTSIZX(channel, usb->index));

    /* Calculating the number of bytes successfully transfered is dependent on
        the transfer direction */
    packets_processed = transaction->pktcnt - usbc_hctsiz.s.pktcnt;
    if (usbc_hcchar.s.epdir)
    {
        /* IN transactions are easy. For every byte received the hardware
            decrements xfersize. All we need to do is subtract the current
            value of xfersize from its starting value and we know how many
            bytes were written to the buffer */
        bytes_this_transfer = transaction->xfersize - usbc_hctsiz.s.xfersize;
    }
    else
    {
        /* OUT transaction don't decrement xfersize. Instead pktcnt is
            decremented on every successful packet send. The hardware does
            this when it receives an ACK, or NYET. If it doesn't
            receive one of these responses pktcnt doesn't change */
        bytes_this_transfer = packets_processed * usbc_hcchar.s.mps;
        /* The last packet may not be a full transfer if we didn't have
            enough data */
        if (bytes_this_transfer > transaction->xfersize)
            bytes_this_transfer = transaction->xfersize;
    }
    /* Figure out how many bytes were in the last packet of the transfer */
    if (packets_processed)
        bytes_in_last_packet = bytes_this_transfer - (packets_processed-1) * usbc_hcchar.s.mps;
    else
        bytes_in_last_packet = bytes_this_transfer;

    /* As a special case, setup transactions output the setup header, not
        the user's data. For this reason we don't count setup data as bytes
        transfered */
    if ((transaction->stage == CVMX_USB_STAGE_SETUP) ||
        (transaction->stage == CVMX_USB_STAGE_SETUP_SPLIT_COMPLETE))
        bytes_this_transfer = 0;

    /* Optional debug output */
    if (cvmx_unlikely((usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEBUG_TRANSFERS) ||
        (pipe->flags & CVMX_USB_PIPE_FLAGS_DEBUG_TRANSFERS)))
        cvmx_dprintf("%s: Channel %d halted. Pipe %d transaction %d stage %d bytes=%d\n",
                     __FUNCTION__, channel,
                     __cvmx_usb_get_pipe_handle(usb, pipe),
                     __cvmx_usb_get_submit_handle(usb, transaction),
                     transaction->stage, bytes_this_transfer);

    /* Add the bytes transfered to the running total. It is important that
        bytes_this_transfer doesn't count any data that needs to be
        retransmitted */
    transaction->actual_bytes += bytes_this_transfer;
    if (transaction->type == CVMX_USB_TRANSFER_ISOCHRONOUS)
        buffer_space_left = transaction->iso_packets[0].length - transaction->actual_bytes;
    else
        buffer_space_left = transaction->buffer_length - transaction->actual_bytes;

    /* We need to remember the PID toggle state for the next transaction. The
        hardware already updated it for the next transaction */
    pipe->pid_toggle = !(usbc_hctsiz.s.pid == 0);

    /* For high speed bulk out, assume the next transaction will need to do a
        ping before proceeding. If this isn't true the ACK processing below
        will clear this flag */
    if ((pipe->device_speed == CVMX_USB_SPEED_HIGH) &&
        (pipe->transfer_type == CVMX_USB_TRANSFER_BULK) &&
        (pipe->transfer_dir == CVMX_USB_DIRECTION_OUT))
        pipe->flags |= __CVMX_USB_PIPE_FLAGS_NEED_PING;

    if (usbc_hcint.s.stall)
    {
        /* STALL as a response means this transaction cannot be completed
            because the device can't process transactions. Tell the user. Any
            data that was transfered will be counted on the actual bytes
            transfered */
        pipe->pid_toggle = 0;
        __cvmx_usb_perform_complete(usb, pipe, transaction, CVMX_USB_COMPLETE_STALL);
    }
    else if (0 && usbc_hcint.s.xfercompl)
    {
        /* XferCompl is only useful in non DMA mode */
    }
    else if (usbc_hcint.s.xacterr)
    {
        /* We know at least one packet worked if we get a ACK or NAK. Reset the retry counter */
        if (usbc_hcint.s.nak || usbc_hcint.s.ack)
            transaction->retries = 0;
        transaction->retries++;
        if (transaction->retries > MAX_RETRIES)
        {
            /* XactErr as a response means the device signaled something wrong with
                the transfer. For example, PID toggle errors cause these */
            __cvmx_usb_perform_complete(usb, pipe, transaction, CVMX_USB_COMPLETE_XACTERR);
        }
        else
        {
            /* Rewind to the beginning of the transaction by anding off the
                split complete bit */
            transaction->stage &= ~1;
            pipe->split_sc_frame = -1;
            pipe->next_tx_cycle = cvmx_read64_uint64(CVMX_IPD_CLK_COUNT) + pipe->interval;
        }
    }
    else if (0 && usbc_hcint.s.datatglerr)
    {
        /* The hardware automatically handles Data Toggle Errors for us */
    }
    else if (usbc_hcint.s.bblerr)
    {
        /* Babble Error (BblErr) */
        __cvmx_usb_perform_complete(usb, pipe, transaction, CVMX_USB_COMPLETE_BABBLEERR);
    }
    else if (usbc_hcint.s.frmovrun)
    {
        /* Frame Overrun (FrmOvrun) */
        /* Rewind to the beginning of the transaction by anding off the
            split complete bit */
        transaction->stage &= ~1;
        pipe->split_sc_frame = -1;
    }
    else if (usbc_hcint.s.nyet)
    {
        /* NYET as a response is only allowed in three cases: as a response to
            a ping, as a response to a split transaction, and as a response to
            a bulk out. The ping case is handled by hardware, so we only have
            splits and bulk out */
        if (!__cvmx_usb_pipe_needs_split(usb, pipe))
        {
            transaction->retries = 0;
            /* If there is more data to go then we need to try again. Otherwise
                this transaction is complete */
            if ((buffer_space_left == 0) || (bytes_in_last_packet < pipe->max_packet))
                __cvmx_usb_perform_complete(usb, pipe, transaction, CVMX_USB_COMPLETE_SUCCESS);
        }
        else
        {
            /* Split transactions retry the split complete 4 times then rewind
                to the start split and do the entire transactions again */
            transaction->retries++;
            if ((transaction->retries & 0x3) == 0)
            {
                /* Rewind to the beginning of the transaction by anding off the
                    split complete bit */
                transaction->stage &= ~1;
                pipe->split_sc_frame = -1;
            }
        }
    }
    else if (usbc_hcint.s.ack)
    {
        transaction->retries = 0;
        /* The ACK bit can only be checked after the other error bits. This is
            because a multi packet transfer may succeed in a number of packets
            and then get a different response on the last packet. In this case
            both ACK and the last response bit will be set. If none of the
            other response bits is set, then the last packet must have been an
            ACK */

        /* Since we got an ACK, we know we don't need to do a ping on this
            pipe */
        pipe->flags &= ~__CVMX_USB_PIPE_FLAGS_NEED_PING;

        switch (transaction->type)
        {
            case CVMX_USB_TRANSFER_CONTROL:
                switch (transaction->stage)
                {
                    case CVMX_USB_STAGE_NON_CONTROL:
                    case CVMX_USB_STAGE_NON_CONTROL_SPLIT_COMPLETE:
                        /* This should be impossible */
                        __cvmx_usb_perform_complete(usb, pipe, transaction, CVMX_USB_COMPLETE_ERROR);
                        break;
                    case CVMX_USB_STAGE_SETUP:
                        pipe->pid_toggle = 1;
                        if (__cvmx_usb_pipe_needs_split(usb, pipe))
                            transaction->stage = CVMX_USB_STAGE_SETUP_SPLIT_COMPLETE;
                        else
                        {
                            cvmx_usb_control_header_t *header = cvmx_phys_to_ptr(transaction->control_header);
                            if (header->s.length)
                                transaction->stage = CVMX_USB_STAGE_DATA;
                            else
                                transaction->stage = CVMX_USB_STAGE_STATUS;
                        }
                        break;
                    case CVMX_USB_STAGE_SETUP_SPLIT_COMPLETE:
                        {
                            cvmx_usb_control_header_t *header = cvmx_phys_to_ptr(transaction->control_header);
                            if (header->s.length)
                                transaction->stage = CVMX_USB_STAGE_DATA;
                            else
                                transaction->stage = CVMX_USB_STAGE_STATUS;
                        }
                        break;
                    case CVMX_USB_STAGE_DATA:
                        if (__cvmx_usb_pipe_needs_split(usb, pipe))
                            transaction->stage = CVMX_USB_STAGE_DATA_SPLIT_COMPLETE;
                        else if ((buffer_space_left == 0) || (bytes_in_last_packet < pipe->max_packet))
                        {
                            pipe->pid_toggle = 1;
                            transaction->stage = CVMX_USB_STAGE_STATUS;
                        }
                        break;
                    case CVMX_USB_STAGE_DATA_SPLIT_COMPLETE:
                        if ((buffer_space_left == 0) || (bytes_in_last_packet < pipe->max_packet))
                        {
                            pipe->pid_toggle = 1;
                            transaction->stage = CVMX_USB_STAGE_STATUS;
                        }
                        else
                        {
                            transaction->stage = CVMX_USB_STAGE_DATA;
                        }
                        break;
                    case CVMX_USB_STAGE_STATUS:
                        if (__cvmx_usb_pipe_needs_split(usb, pipe))
                            transaction->stage = CVMX_USB_STAGE_STATUS_SPLIT_COMPLETE;
                        else
                            __cvmx_usb_perform_complete(usb, pipe, transaction, CVMX_USB_COMPLETE_SUCCESS);
                        break;
                    case CVMX_USB_STAGE_STATUS_SPLIT_COMPLETE:
                        __cvmx_usb_perform_complete(usb, pipe, transaction, CVMX_USB_COMPLETE_SUCCESS);
                        break;
                }
                break;
            case CVMX_USB_TRANSFER_BULK:
            case CVMX_USB_TRANSFER_INTERRUPT:
                /* The only time a bulk transfer isn't complete when
                    it finishes with an ACK is during a split transaction. For
                    splits we need to continue the transfer if more data is
                    needed */
                if (__cvmx_usb_pipe_needs_split(usb, pipe))
                {
                    if (transaction->stage == CVMX_USB_STAGE_NON_CONTROL)
                        transaction->stage = CVMX_USB_STAGE_NON_CONTROL_SPLIT_COMPLETE;
                    else
                    {
                        if (buffer_space_left && (bytes_in_last_packet == pipe->max_packet))
                            transaction->stage = CVMX_USB_STAGE_NON_CONTROL;
                        else
                        {
                            if (transaction->type == CVMX_USB_TRANSFER_INTERRUPT)
                                pipe->next_tx_cycle += pipe->interval;
                            __cvmx_usb_perform_complete(usb, pipe, transaction, CVMX_USB_COMPLETE_SUCCESS);
                        }
                    }
                }
                else
                {
                    if ((pipe->device_speed == CVMX_USB_SPEED_HIGH) &&
                        (pipe->transfer_type == CVMX_USB_TRANSFER_BULK) &&
                        (pipe->transfer_dir == CVMX_USB_DIRECTION_OUT) &&
                        (usbc_hcint.s.nak))
                        pipe->flags |= __CVMX_USB_PIPE_FLAGS_NEED_PING;
                    if (!buffer_space_left || (bytes_in_last_packet < pipe->max_packet))
                    {
                        if (transaction->type == CVMX_USB_TRANSFER_INTERRUPT)
                            pipe->next_tx_cycle += pipe->interval;
                        __cvmx_usb_perform_complete(usb, pipe, transaction, CVMX_USB_COMPLETE_SUCCESS);
                    }
                }
                break;
            case CVMX_USB_TRANSFER_ISOCHRONOUS:
                if (__cvmx_usb_pipe_needs_split(usb, pipe))
                {
                    /* ISOCHRONOUS OUT splits don't require a complete split stage.
                        Instead they use a sequence of begin OUT splits to transfer
                        the data 188 bytes at a time. Once the transfer is complete,
                        the pipe sleeps until the next schedule interval */
                    if (pipe->transfer_dir == CVMX_USB_DIRECTION_OUT)
                    {
                        pipe->next_tx_cycle += pipe->interval;
                        /* If no space left or this wasn't a max size packet then
                            this transfer is complete. Otherwise start it again
                            to send the next 188 bytes */
                        if (!buffer_space_left || (bytes_this_transfer < 188))
                            __cvmx_usb_perform_complete(usb, pipe, transaction, CVMX_USB_COMPLETE_SUCCESS);
                    }
                    else
                    {
                        if (transaction->stage == CVMX_USB_STAGE_NON_CONTROL_SPLIT_COMPLETE)
                        {
                            /* We are in the incomming data phase. Keep getting
                                data until we run out of space or get a small
                                packet */
                            if ((buffer_space_left == 0) || (bytes_in_last_packet < pipe->max_packet))
                            {
                                pipe->next_tx_cycle += pipe->interval;
                                __cvmx_usb_perform_complete(usb, pipe, transaction, CVMX_USB_COMPLETE_SUCCESS);
                            }
                        }
                        else
                            transaction->stage = CVMX_USB_STAGE_NON_CONTROL_SPLIT_COMPLETE;
                    }
                }
                else
                {
                    pipe->next_tx_cycle += pipe->interval;
                    __cvmx_usb_perform_complete(usb, pipe, transaction, CVMX_USB_COMPLETE_SUCCESS);
                }
                break;
        }
    }
    else if (usbc_hcint.s.nak)
    {
        uint64_t ipd_clk_count;
        /* NAK as a response means the device couldn't accept the transaction,
            but it should be retried in the future. Rewind to the beginning of
            the transaction by anding off the split complete bit. Retry in the
            next interval */
        transaction->retries = 0;
        transaction->stage &= ~1;
        pipe->next_tx_cycle += pipe->interval;
        ipd_clk_count = cvmx_read64_uint64(CVMX_IPD_CLK_COUNT);
        if (pipe->next_tx_cycle < ipd_clk_count)
            pipe->next_tx_cycle = ipd_clk_count + pipe->interval;
    }
    else
    {
        /* We get channel halted interrupts with no result bits sets when the
            cable is unplugged */
        __cvmx_usb_perform_complete(usb, pipe, transaction, CVMX_USB_COMPLETE_ERROR);
    }
    CVMX_USB_RETURN(0);
}


/**
 * Poll a device mode endpoint for status
 *
 * @param usb    USB device state populated by
 *               cvmx_usb_initialize().
 * @param endpoint_num
 *               Endpoint to poll
 *
 * @return Zero on success
 */
static int __cvmx_usb_poll_endpoint(cvmx_usb_internal_state_t *usb, int endpoint_num)
{
    cvmx_usbcx_diepintx_t usbc_diepint;
    cvmx_usbcx_doepintx_t usbc_doepint;

    CVMX_USB_LOG_CALLED();
    CVMX_USB_LOG_PARAM("%p", usb);
    CVMX_USB_LOG_PARAM("%d", endpoint_num);

    usbc_diepint.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_DIEPINTX(endpoint_num, usb->index));
    __cvmx_usb_write_csr32(usb, CVMX_USBCX_DIEPINTX(endpoint_num, usb->index), usbc_diepint.u32);
    //cvmx_csr_db_decode(cvmx_get_proc_id(), CVMX_USBCX_DIEPINTX(endpoint_num, usb->index), usbc_diepint.u32);
    if (usbc_diepint.s.inepnakeff)
    {
        /* IN Endpoint NAK Effective (INEPNakEff)
            Applies to periodic IN endpoints only.
            Indicates that the IN endpoint NAK bit set by the application has
            taken effect in the core. This bit can be cleared when the
            application clears the IN endpoint NAK by writing to
            DIEPCTLn.CNAK.
            This interrupt indicates that the core has sampled the NAK bit
            set (either by the application or by the core).
            This interrupt does not necessarily mean that a NAK handshake
            is sent on the USB. A STALL bit takes priority over a NAK bit. */
        /* Nothing to do */
    }
    if (usbc_diepint.s.intknepmis)
    {
        /* IN Token Received with EP Mismatch (INTknEPMis)
            Applies to non-periodic IN endpoints only.
            Indicates that the data in the top of the non-periodic TxFIFO
            belongs to an endpoint other than the one for which the IN
            token was received. This interrupt is asserted on the endpoint
            for which the IN token was received. */
        if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEBUG_INFO))
            cvmx_dprintf("%s: Endpoint %d mismatch\n", __FUNCTION__, endpoint_num);
    }
    if (usbc_diepint.s.intkntxfemp)
    {
        /* IN Token Received When TxFIFO is Empty (INTknTXFEmp)
            Applies only to non-periodic IN endpoints.
            Indicates that an IN token was received when the associated
            TxFIFO (periodic/non-periodic) was empty. This interrupt is
            asserted on the endpoint for which the IN token was received. */
        if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEBUG_INFO))
            cvmx_dprintf("%s: Received IN token on endpoint %d without data\n", __FUNCTION__, endpoint_num);
    }
    if (usbc_diepint.s.timeout)
    {
        /* Timeout Condition (TimeOUT)
            Applies to non-isochronous IN endpoints only.
            Indicates that the core has detected a timeout condition on the
            USB for the last IN token on this endpoint. */
        if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEBUG_INFO))
            cvmx_dprintf("%s: Received timeout on endpoint %d\n", __FUNCTION__, endpoint_num);
    }
    if (usbc_diepint.s.ahberr)
    {
        /* AHB Error (AHBErr)
            This is generated only in Internal DMA mode when there is an
            AHB error during an AHB read/write. The application can read
            the corresponding endpoint DMA address register to get the
            error address. */
        if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEBUG_INFO))
            cvmx_dprintf("%s: AHB error on endpoint %d\n", __FUNCTION__, endpoint_num);
    }
    if (usbc_diepint.s.epdisbld)
    {
        /* Endpoint Disabled Interrupt (EPDisbld)
            This bit indicates that the endpoint is disabled per the
            application's request. */
        /* Nothing to do */
    }
    if (usbc_diepint.s.xfercompl)
    {
        /* Transfer Completed Interrupt (XferCompl)
            Indicates that the programmed transfer is complete on the AHB
            as well as on the USB, for this endpoint. */
        __cvmx_usb_perform_callback(usb, usb->pipe + endpoint_num, NULL,
                                    CVMX_USB_CALLBACK_TRANSFER_COMPLETE,
                                    CVMX_USB_COMPLETE_SUCCESS);
    }

    usbc_doepint.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_DOEPINTX(endpoint_num, usb->index));
    __cvmx_usb_write_csr32(usb, CVMX_USBCX_DOEPINTX(endpoint_num, usb->index), usbc_doepint.u32);
    //cvmx_csr_db_decode(cvmx_get_proc_id(), CVMX_USBCX_DOEPINTX(endpoint_num, usb->index), usbc_doepint.u32);
    if (usbc_doepint.s.outtknepdis)
    {
        /* OUT Token Received When Endpoint Disabled (OUTTknEPdis)
            Applies only to control OUT endpoints.
            Indicates that an OUT token was received when the endpoint
            was not yet enabled. This interrupt is asserted on the endpoint
            for which the OUT token was received. */
        if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEBUG_INFO))
            cvmx_dprintf("%s: Received OUT token on disabled endpoint %d\n", __FUNCTION__, endpoint_num);
    }
    if (usbc_doepint.s.setup)
    {
        /* SETUP Phase Done (SetUp)
            Applies to control OUT endpoints only.
            Indicates that the SETUP phase for the control endpoint is
            complete and no more back-to-back SETUP packets were
            received for the current control transfer. On this interrupt, the
            application can decode the received SETUP data packet. */
        __cvmx_usb_perform_callback(usb, usb->pipe + endpoint_num, NULL,
                                    CVMX_USB_CALLBACK_DEVICE_SETUP,
                                    CVMX_USB_COMPLETE_SUCCESS);
    }
    if (usbc_doepint.s.ahberr)
    {
        /* AHB Error (AHBErr)
            This is generated only in Internal DMA mode when there is an
            AHB error during an AHB read/write. The application can read
            the corresponding endpoint DMA address register to get the
            error address. */
        if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEBUG_INFO))
            cvmx_dprintf("%s: AHB error on endpoint %d\n", __FUNCTION__, endpoint_num);
    }
    if (usbc_doepint.s.epdisbld)
    {
        /* Endpoint Disabled Interrupt (EPDisbld)
            This bit indicates that the endpoint is disabled per the
            application's request. */
        /* Nothing to do */
    }
    if (usbc_doepint.s.xfercompl)
    {
        /* Transfer Completed Interrupt (XferCompl)
            Indicates that the programmed transfer is complete on the AHB
            as well as on the USB, for this endpoint. */
        __cvmx_usb_perform_callback(usb, usb->pipe + endpoint_num, NULL,
                                    CVMX_USB_CALLBACK_TRANSFER_COMPLETE,
                                    CVMX_USB_COMPLETE_SUCCESS);
    }

    CVMX_USB_RETURN(0);
}


/**
 * Poll the device mode endpoints for status
 *
 * @param usb  USB device state populated by
 *               cvmx_usb_initialize().
 *
 * @return Zero on success
 */
static int __cvmx_usb_poll_endpoints(cvmx_usb_internal_state_t *usb)
{
    cvmx_usbcx_daint_t usbc_daint;
    int active_endpoints;

    CVMX_USB_LOG_CALLED();
    CVMX_USB_LOG_PARAM("%p", usb);

    usbc_daint.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_DAINT(usb->index));
    active_endpoints = usbc_daint.s.inepint | usbc_daint.s.outepint;

    while (active_endpoints)
    {
        int endpoint;
        CVMX_CLZ(endpoint, active_endpoints);
        endpoint = 31 - endpoint;
        __cvmx_usb_poll_endpoint(usb, endpoint);
        active_endpoints ^= 1<<endpoint;
    }

    CVMX_USB_RETURN(0);
}


/**
 * Poll the USB block for status and call all needed callback
 * handlers. This function is meant to be called in the interrupt
 * handler for the USB controller. It can also be called
 * periodically in a loop for non-interrupt based operation.
 *
 * @param state  USB device state populated by
 *               cvmx_usb_initialize().
 *
 * @return CVMX_USB_SUCCESS or a negative error code defined in
 *         cvmx_usb_status_t.
 */
cvmx_usb_status_t cvmx_usb_poll(cvmx_usb_state_t *state)
{
    cvmx_usbcx_gintsts_t usbc_gintsts;
    cvmx_usb_internal_state_t *usb = (cvmx_usb_internal_state_t*)state;

    CVMX_PREFETCH(usb, 0);
    CVMX_PREFETCH(usb, 1*128);
    CVMX_PREFETCH(usb, 2*128);
    CVMX_PREFETCH(usb, 3*128);
    CVMX_PREFETCH(usb, 4*128);

    CVMX_USB_LOG_CALLED();
    CVMX_USB_LOG_PARAM("%p", state);

    /* Read the pending interrupts */
    usbc_gintsts.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_GINTSTS(usb->index));

    if (usbc_gintsts.s.wkupint)
    {
        /* Resume/Remote Wakeup Detected Interrupt (WkUpInt)
            In Device mode, this interrupt is asserted when a resume is
            detected on the USB. In Host mode, this interrupt is asserted
            when a remote wakeup is detected on the USB. */
        /* Octeon doesn't support suspend / resume */
    }
    if (usbc_gintsts.s.sessreqint)
    {
        /* Session Request/New Session Detected Interrupt (SessReqInt)
            In Host mode, this interrupt is asserted when a session request
            is detected from the device. In Device mode, this interrupt is
            asserted when the utmiotg_bvalid signal goes high. */
        /* Octeon doesn't support OTG */
    }
    if (usbc_gintsts.s.disconnint || usbc_gintsts.s.prtint)
    {
        cvmx_usbcx_hprt_t usbc_hprt;
        /* Disconnect Detected Interrupt (DisconnInt)
            Asserted when a device disconnect is detected. */

        /* Host Port Interrupt (PrtInt)
            The core sets this bit to indicate a change in port status of one
            of the O2P USB core ports in Host mode. The application must
            read the Host Port Control and Status (HPRT) register to
            determine the exact event that caused this interrupt. The
            application must clear the appropriate status bit in the Host Port
            Control and Status register to clear this bit. */

        /* Call the user's port callback */
        __cvmx_usb_perform_callback(usb, NULL, NULL,
                                    CVMX_USB_CALLBACK_PORT_CHANGED,
                                    CVMX_USB_COMPLETE_SUCCESS);
        /* Clear the port change bits */
        usbc_hprt.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_HPRT(usb->index));
        usbc_hprt.s.prtena = 0;
        __cvmx_usb_write_csr32(usb, CVMX_USBCX_HPRT(usb->index), usbc_hprt.u32);
    }
    if (usbc_gintsts.s.conidstschng)
    {
        /* Connector ID Status Change (ConIDStsChng)
            The core sets this bit when there is a change in connector ID
            status. */
        /* The USB core currently doesn't support dynamically changing from
            host to device mode */
    }
    if (usbc_gintsts.s.ptxfemp)
    {
        /* Periodic TxFIFO Empty (PTxFEmp)
            Asserted when the Periodic Transmit FIFO is either half or
            completely empty and there is space for at least one entry to be
            written in the Periodic Request Queue. The half or completely
            empty status is determined by the Periodic TxFIFO Empty Level
            bit in the Core AHB Configuration register
            (GAHBCFG.PTxFEmpLvl). */
        /* In DMA mode we don't care */
    }
    if (usbc_gintsts.s.hchint)
    {
        /* Host Channels Interrupt (HChInt)
            The core sets this bit to indicate that an interrupt is pending on
            one of the channels of the core (in Host mode). The application
            must read the Host All Channels Interrupt (HAINT) register to
            determine the exact number of the channel on which the
            interrupt occurred, and then read the corresponding Host
            Channel-n Interrupt (HCINTn) register to determine the exact
            cause of the interrupt. The application must clear the
            appropriate status bit in the HCINTn register to clear this bit. */
        cvmx_usbcx_haint_t usbc_haint;
        usbc_haint.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_HAINT(usb->index));
        while (usbc_haint.u32)
        {
            int channel;
            CVMX_CLZ(channel, usbc_haint.u32);
            channel = 31 - channel;
            __cvmx_usb_poll_channel(usb, channel);
            usbc_haint.u32 ^= 1<<channel;
        }
    }
    if (usbc_gintsts.s.fetsusp)
    {
        /* Data Fetch Suspended (FetSusp)
            This interrupt is valid only in DMA mode. This interrupt indicates
            that the core has stopped fetching data for IN endpoints due to
            the unavailability of TxFIFO space or Request Queue space.
            This interrupt is used by the application for an endpoint
            mismatch algorithm. */
        // FIXME
    }
    if (usbc_gintsts.s.incomplp)
    {
        /* Incomplete Periodic Transfer (incomplP)
            In Host mode, the core sets this interrupt bit when there are
            incomplete periodic transactions still pending which are
            scheduled for the current microframe.
            Incomplete Isochronous OUT Transfer (incompISOOUT)
            The Device mode, the core sets this interrupt to indicate that
            there is at least one isochronous OUT endpoint on which the
            transfer is not completed in the current microframe. This
            interrupt is asserted along with the End of Periodic Frame
            Interrupt (EOPF) bit in this register. */
        // FIXME
    }
    if (usbc_gintsts.s.incompisoin)
    {
        /* Incomplete Isochronous IN Transfer (incompISOIN)
            The core sets this interrupt to indicate that there is at least one
            isochronous IN endpoint on which the transfer is not completed
            in the current microframe. This interrupt is asserted along with
            the End of Periodic Frame Interrupt (EOPF) bit in this register. */
        // FIXME
    }
    if (usbc_gintsts.s.oepint)
    {
        /* OUT Endpoints Interrupt (OEPInt)
            The core sets this bit to indicate that an interrupt is pending on
            one of the OUT endpoints of the core (in Device mode). The
            application must read the Device All Endpoints Interrupt
            (DAINT) register to determine the exact number of the OUT
            endpoint on which the interrupt occurred, and then read the
            corresponding Device OUT Endpoint-n Interrupt (DOEPINTn)
            register to determine the exact cause of the interrupt. The
            application must clear the appropriate status bit in the
            corresponding DOEPINTn register to clear this bit. */
        __cvmx_usb_poll_endpoints(usb);
    }
    if (usbc_gintsts.s.iepint)
    {
        /* IN Endpoints Interrupt (IEPInt)
            The core sets this bit to indicate that an interrupt is pending on
            one of the IN endpoints of the core (in Device mode). The
            application must read the Device All Endpoints Interrupt
            (DAINT) register to determine the exact number of the IN
            endpoint on which the interrupt occurred, and then read the
            corresponding Device IN Endpoint-n Interrupt (DIEPINTn)
            register to determine the exact cause of the interrupt. The
            application must clear the appropriate status bit in the
            corresponding DIEPINTn register to clear this bit. */
        __cvmx_usb_poll_endpoints(usb);
    }
    if (usbc_gintsts.s.epmis)
    {
        /* Endpoint Mismatch Interrupt (EPMis)
            Indicates that an IN token has been received for a non-periodic
            endpoint, but the data for another endpoint is present in the top
            of the Non-Periodic Transmit FIFO and the IN endpoint
            mismatch count programmed by the application has expired. */
        // FIXME
    }
    if (usbc_gintsts.s.eopf)
    {
        /* End of Periodic Frame Interrupt (EOPF)
            Indicates that the period specified in the Periodic Frame Interval
            field of the Device Configuration register (DCFG.PerFrInt) has
            been reached in the current microframe. */
        // FIXME
    }
    if (usbc_gintsts.s.isooutdrop)
    {
        /* Isochronous OUT Packet Dropped Interrupt (ISOOutDrop)
            The core sets this bit when it fails to write an isochronous OUT
            packet into the RxFIFO because the RxFIFO doesn't have
            enough space to accommodate a maximum packet size packet
            for the isochronous OUT endpoint. */
        // FIXME
    }
    if (usbc_gintsts.s.enumdone)
    {
        /* Enumeration Done (EnumDone)
            The core sets this bit to indicate that speed enumeration is
            complete. The application must read the Device Status (DSTS)
            register to obtain the enumerated speed. */
        if (usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEVICE_MODE)
        {
            cvmx_usbcx_dsts_t usbc_dsts;
            usbc_dsts.u32 = __cvmx_usb_read_csr32(usb, CVMX_USBCX_DSTS(usb->index));
            if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEBUG_INFO))
                cvmx_dprintf("%s: USB%d Enumeration complete with %s speed\n",
                             __FUNCTION__, usb->index,
                             (usbc_dsts.s.enumspd == CVMX_USB_SPEED_HIGH) ? "high" :
                             (usbc_dsts.s.enumspd == CVMX_USB_SPEED_FULL) ? "full" :
                             "low");
            USB_SET_FIELD32(CVMX_USBCX_DIEPCTLX(0, usb->index),
                            cvmx_usbcx_diepctlx_t, mps,
                            (usbc_dsts.s.enumspd == CVMX_USB_SPEED_LOW) ? 3 : 0);
            USB_SET_FIELD32(CVMX_USBCX_DOEPCTLX(0, usb->index),
                            cvmx_usbcx_doepctlx_t, epena, 1);
        }
    }
    if (usbc_gintsts.s.usbrst)
    {
        /* USB Reset (USBRst)
            The core sets this bit to indicate that a reset is
            detected on the USB. */
        if (usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEVICE_MODE)
        {
            if (cvmx_unlikely(usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEBUG_INFO))
                cvmx_dprintf("%s: USB%d Reset complete\n", __FUNCTION__, usb->index);
            __cvmx_usb_device_reset_complete(usb);
        }
    }
    if (usbc_gintsts.s.nptxfemp)
    {
        /* Non-Periodic TxFIFO Empty (NPTxFEmp)
            This interrupt is asserted when the Non-Periodic TxFIFO is
            either half or completely empty, and there is space for at least
            one entry to be written to the Non-Periodic Transmit Request
            Queue. The half or completely empty status is determined by
            the Non-Periodic TxFIFO Empty Level bit in the Core AHB
            Configuration register (GAHBCFG.NPTxFEmpLvl). */
        /* In DMA mode this is handled by hardware */
    }
    if (usbc_gintsts.s.rxflvl)
    {
        /* RxFIFO Non-Empty (RxFLvl)
            Indicates that there is at least one packet pending to be read
            from the RxFIFO. */
        /* In DMA mode this is handled by hardware */
    }
    if (usbc_gintsts.s.sof)
    {
        /* Start of (micro)Frame (Sof)
            In Host mode, the core sets this bit to indicate that an SOF
            (FS), micro-SOF (HS), or Keep-Alive (LS) is transmitted on the
            USB. The application must write a 1 to this bit to clear the
            interrupt.
            In Device mode, in the core sets this bit to indicate that an SOF
            token has been received on the USB. The application can read
            the Device Status register to get the current (micro)frame
            number. This interrupt is seen only when the core is operating
            at either HS or FS. */
    }
    if (usbc_gintsts.s.otgint)
    {
        /* OTG Interrupt (OTGInt)
            The core sets this bit to indicate an OTG protocol event. The
            application must read the OTG Interrupt Status (GOTGINT)
            register to determine the exact event that caused this interrupt.
            The application must clear the appropriate status bit in the
            GOTGINT register to clear this bit. */
        /* Octeon doesn't support OTG, so ignore */
    }
    if (usbc_gintsts.s.modemis)
    {
        /* Mode Mismatch Interrupt (ModeMis)
            The core sets this bit when the application is trying to access:
            * A Host mode register, when the core is operating in Device
            mode
            * A Device mode register, when the core is operating in Host
            mode
            The register access is completed on the AHB with an OKAY
            response, but is ignored by the core internally and doesn't
            affect the operation of the core. */
        /* Ignored for now */
    }

    __cvmx_usb_schedule(usb, usbc_gintsts.s.sof);

    /* Clear the interrupts now that we know about them */
    __cvmx_usb_write_csr32(usb, CVMX_USBCX_GINTSTS(usb->index), usbc_gintsts.u32);

    CVMX_USB_RETURN(CVMX_USB_SUCCESS);
}


/**
 * Enable an endpoint for use in device mode. After this call
 * transactions will be allowed over the endpoint. This must be
 * called after every usb reset.
 *
 * @param state  USB device state populated by
 *               cvmx_usb_initialize().
 * @param endpoint_num
 *               The endpoint number to enable (0-4)
 * @param transfer_type
 *               USB transfer type of this endpoint
 * @param transfer_dir
 *               Direction of transfer relative to Octeon
 * @param max_packet_size
 *               Maximum packet size support by this endpoint
 * @param buffer Buffer to send/receive
 * @param buffer_length
 *               Length of the buffer in bytes
 *
 * @return CVMX_USB_SUCCESS or a negative error code defined in
 *         cvmx_usb_status_t.
 */
cvmx_usb_status_t cvmx_usb_device_enable_endpoint(cvmx_usb_state_t *state,
                                                  int endpoint_num,
                                                  cvmx_usb_transfer_t transfer_type,
                                                  cvmx_usb_direction_t transfer_dir,
                                                  int max_packet_size,
                                                  uint64_t buffer,
                                                  int buffer_length)
{
    cvmx_usb_internal_state_t *usb = (cvmx_usb_internal_state_t*)state;

    CVMX_USB_LOG_CALLED();
    CVMX_USB_LOG_PARAM("%p", state);
    CVMX_USB_LOG_PARAM("%d", endpoint_num);
    CVMX_USB_LOG_PARAM("%d", transfer_type);
    CVMX_USB_LOG_PARAM("%d", transfer_dir);
    CVMX_USB_LOG_PARAM("%d", max_packet_size);
    CVMX_USB_LOG_PARAM("0x%llx", (unsigned long long)buffer);
    CVMX_USB_LOG_PARAM("%d", buffer_length);

    if (cvmx_unlikely((endpoint_num < 0) || (endpoint_num > 4)))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely(transfer_type > CVMX_USB_TRANSFER_INTERRUPT))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely((transfer_dir != CVMX_USB_DIRECTION_OUT) &&
        (transfer_dir != CVMX_USB_DIRECTION_IN)))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely((max_packet_size < 0) || (max_packet_size > 512)))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely(!buffer))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely(buffer_length < 0))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely((usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEVICE_MODE) == 0))
        CVMX_USB_RETURN(CVMX_USB_INCORRECT_MODE);

    if (transfer_dir == CVMX_USB_DIRECTION_IN)
    {
        cvmx_usbcx_doepctlx_t usbc_doepctl;
        cvmx_usbcx_doeptsizx_t usbc_doeptsiz;

        /* Setup the locations the DMA engines use  */
        __cvmx_usb_write_csr64(usb, CVMX_USBNX_DMA0_INB_CHN0(usb->index) + endpoint_num*8, buffer);
        usbc_doeptsiz.u32 = 0;
        usbc_doeptsiz.s.mc = 1; // FIXME
        usbc_doeptsiz.s.pktcnt = (buffer_length + max_packet_size - 1) / max_packet_size;
        if (usbc_doeptsiz.s.pktcnt == 0)
            usbc_doeptsiz.s.pktcnt = 1;
        usbc_doeptsiz.s.xfersize = buffer_length;
        __cvmx_usb_write_csr32(usb, CVMX_USBCX_DOEPTSIZX(endpoint_num, usb->index), usbc_doeptsiz.u32);

        usbc_doepctl.u32 = 0;
        usbc_doepctl.s.epena = 1;
        usbc_doepctl.s.setd1pid = 0; // FIXME
        usbc_doepctl.s.setd0pid = 0; // FIXME
        usbc_doepctl.s.cnak = 1;
        usbc_doepctl.s.eptype = transfer_type;
        usbc_doepctl.s.usbactep = 1;
        usbc_doepctl.s.mps = max_packet_size;
        __cvmx_usb_write_csr32(usb, CVMX_USBCX_DOEPCTLX(endpoint_num, usb->index), usbc_doepctl.u32);
    }
    else
    {
        cvmx_usbcx_diepctlx_t usbc_diepctl;
        cvmx_usbcx_dieptsizx_t usbc_dieptsiz;

        /* Setup the locations the DMA engines use  */
        __cvmx_usb_write_csr64(usb, CVMX_USBNX_DMA0_OUTB_CHN0(usb->index) + endpoint_num*8, buffer);
        usbc_dieptsiz.u32 = 0;
        usbc_dieptsiz.s.mc = 1; // FIXME
        usbc_dieptsiz.s.pktcnt = (buffer_length + max_packet_size - 1) / max_packet_size;
        if (usbc_dieptsiz.s.pktcnt == 0)
            usbc_dieptsiz.s.pktcnt = 1;
        usbc_dieptsiz.s.xfersize = buffer_length;
        __cvmx_usb_write_csr32(usb, CVMX_USBCX_DIEPTSIZX(endpoint_num, usb->index), usbc_dieptsiz.u32);

        usbc_diepctl.u32 = 0;
        usbc_diepctl.s.epena = 1;
        usbc_diepctl.s.setd1pid = 0; // FIXME
        usbc_diepctl.s.setd0pid = 0; // FIXME
        usbc_diepctl.s.cnak = 1;
        if ((transfer_type == CVMX_USB_TRANSFER_INTERRUPT) ||
            (transfer_type == CVMX_USB_TRANSFER_ISOCHRONOUS))
            usbc_diepctl.s.txfnum = endpoint_num; // FIXME
        else
            usbc_diepctl.s.txfnum = 0;
        usbc_diepctl.s.eptype = transfer_type;
        usbc_diepctl.s.usbactep = 1;
        usbc_diepctl.s.nextep = endpoint_num - 1; // FIXME
        usbc_diepctl.s.mps = max_packet_size;
        __cvmx_usb_write_csr32(usb, CVMX_USBCX_DIEPCTLX(endpoint_num, usb->index), usbc_diepctl.u32);
    }

    CVMX_USB_RETURN(CVMX_USB_SUCCESS);
}


/**
 * Disable an endpoint in device mode.
 *
 * @param state  USB device state populated by
 *               cvmx_usb_initialize().
 * @param endpoint_num
 *               The endpoint number to disable (0-4)
 *
 * @return CVMX_USB_SUCCESS or a negative error code defined in
 *         cvmx_usb_status_t.
 */
cvmx_usb_status_t cvmx_usb_device_disable_endpoint(cvmx_usb_state_t *state,
                                                   int endpoint_num)
{
    cvmx_usb_internal_state_t *usb = (cvmx_usb_internal_state_t*)state;

    CVMX_USB_LOG_CALLED();
    CVMX_USB_LOG_PARAM("%p", state);
    CVMX_USB_LOG_PARAM("%d", endpoint_num);

    if (cvmx_unlikely((endpoint_num < 0) || (endpoint_num > 4)))
        CVMX_USB_RETURN(CVMX_USB_INVALID_PARAM);
    if (cvmx_unlikely((usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_DEVICE_MODE) == 0))
        CVMX_USB_RETURN(CVMX_USB_INCORRECT_MODE);

    USB_SET_FIELD32(CVMX_USBCX_DOEPCTLX(endpoint_num, usb->index),
                    cvmx_usbcx_doepctlx_t, epdis, 1);
    USB_SET_FIELD32(CVMX_USBCX_DIEPCTLX(endpoint_num, usb->index),
                    cvmx_usbcx_diepctlx_t, epdis, 1);

    CVMX_USB_RETURN(CVMX_USB_SUCCESS);
}

extern void cvmx_usb_set_toggle(cvmx_usb_state_t *state, int endpoint_num, int toggle)
{
    cvmx_usb_internal_state_t *usb = (cvmx_usb_internal_state_t*)state;
    cvmx_usb_pipe_t *pipe = usb->pipe + endpoint_num;

    pipe->pid_toggle = !!toggle;
}

extern int cvmx_usb_get_toggle(cvmx_usb_state_t *state, int endpoint_num)
{
    cvmx_usb_internal_state_t *usb = (cvmx_usb_internal_state_t*)state;
    cvmx_usb_pipe_t *pipe = usb->pipe + endpoint_num;

    if (pipe->pid_toggle)
	    return (1);
    return (0);
}