smscusb.c

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/*
 * Copyright (C) 2017 Michael Brown <mbrown@fensystems.co.uk>.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 *
 * You can also choose to distribute this program under the terms of
 * the Unmodified Binary Distribution Licence (as given in the file
 * COPYING.UBDL), provided that you have satisfied its requirements.
 */

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
FILE_SECBOOT ( PERMITTED );

#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <ipxe/usb.h>
#include <ipxe/usbnet.h>
#include <ipxe/ethernet.h>
#include <ipxe/profile.h>
#include <ipxe/fdt.h>
#include "smscusb.h"

/** @file
 *
 * SMSC USB Ethernet drivers
 *
 */

/** Interrupt completion profiler */
static struct profiler smscusb_intr_profiler __profiler =
        { .name = "smscusb.intr" };

/******************************************************************************
 *
 * Register access
 *
 ******************************************************************************
 */

/**
 * Write register (without byte-swapping)
 *
 * @v smscusb           Smscusb device
 * @v address           Register address
 * @v value             Register value
 * @ret rc              Return status code
 */
int smscusb_raw_writel ( struct smscusb_device *smscusb, unsigned int address,
                         uint32_t value ) {
        int rc;

        /* Write register */
        DBGCIO ( smscusb, "SMSCUSB %p [%03x] <= %08x\n",
                 smscusb, address, le32_to_cpu ( value ) );
        if ( ( rc = usb_control ( smscusb->usb, SMSCUSB_REGISTER_WRITE, 0,
                                  address, &value, sizeof ( value ) ) ) != 0 ) {
                DBGC ( smscusb, "SMSCUSB %p could not write %03x: %s\n",
                       smscusb, address, strerror ( rc ) );
                return rc;
        }

        return 0;
}

/**
 * Read register (without byte-swapping)
 *
 * @v smscusb           SMSC USB device
 * @v address           Register address
 * @ret value           Register value
 * @ret rc              Return status code
 */
int smscusb_raw_readl ( struct smscusb_device *smscusb, unsigned int address,
                        uint32_t *value ) {
        int rc;

        /* Read register */
        if ( ( rc = usb_control ( smscusb->usb, SMSCUSB_REGISTER_READ, 0,
                                  address, value, sizeof ( *value ) ) ) != 0 ) {
                DBGC ( smscusb, "SMSCUSB %p could not read %03x: %s\n",
                       smscusb, address, strerror ( rc ) );
                return rc;
        }
        DBGCIO ( smscusb, "SMSCUSB %p [%03x] => %08x\n",
                 smscusb, address, le32_to_cpu ( *value ) );

        return 0;
}

/******************************************************************************
 *
 * EEPROM access
 *
 ******************************************************************************
 */

/**
 * Wait for EEPROM to become idle
 *
 * @v smscusb           SMSC USB device
 * @v e2p_base          E2P register base
 * @ret rc              Return status code
 */
static int smscusb_eeprom_wait ( struct smscusb_device *smscusb,
                                 unsigned int e2p_base ) {
        uint32_t e2p_cmd;
        unsigned int i;
        int rc;

        /* Wait for EPC_BSY to become clear */
        for ( i = 0 ; i < SMSCUSB_EEPROM_MAX_WAIT_MS ; i++ ) {

                /* Read E2P_CMD and check EPC_BSY */
                if ( ( rc = smscusb_readl ( smscusb,
                                            ( e2p_base + SMSCUSB_E2P_CMD ),
                                            &e2p_cmd ) ) != 0 )
                        return rc;
                if ( ! ( e2p_cmd & SMSCUSB_E2P_CMD_EPC_BSY ) )
                        return 0;

                /* Delay */
                mdelay ( 1 );
        }

        DBGC ( smscusb, "SMSCUSB %p timed out waiting for EEPROM\n",
               smscusb );
        return -ETIMEDOUT;
}

/**
 * Read byte from EEPROM
 *
 * @v smscusb           SMSC USB device
 * @v e2p_base          E2P register base
 * @v address           EEPROM address
 * @ret byte            Byte read, or negative error
 */
static int smscusb_eeprom_read_byte ( struct smscusb_device *smscusb,
                                      unsigned int e2p_base,
                                      unsigned int address ) {
        uint32_t e2p_cmd;
        uint32_t e2p_data;
        int rc;

        /* Wait for EEPROM to become idle */
        if ( ( rc = smscusb_eeprom_wait ( smscusb, e2p_base ) ) != 0 )
                return rc;

        /* Initiate read command */
        e2p_cmd = ( SMSCUSB_E2P_CMD_EPC_BSY | SMSCUSB_E2P_CMD_EPC_CMD_READ |
                    SMSCUSB_E2P_CMD_EPC_ADDR ( address ) );
        if ( ( rc = smscusb_writel ( smscusb, ( e2p_base + SMSCUSB_E2P_CMD ),
                                     e2p_cmd ) ) != 0 )
                return rc;

        /* Wait for command to complete */
        if ( ( rc = smscusb_eeprom_wait ( smscusb, e2p_base ) ) != 0 )
                return rc;

        /* Read EEPROM data */
        if ( ( rc = smscusb_readl ( smscusb, ( e2p_base + SMSCUSB_E2P_DATA ),
                                    &e2p_data ) ) != 0 )
                return rc;

        return SMSCUSB_E2P_DATA_GET ( e2p_data );
}

/**
 * Read data from EEPROM
 *
 * @v smscusb           SMSC USB device
 * @v e2p_base          E2P register base
 * @v address           EEPROM address
 * @v data              Data buffer
 * @v len               Length of data
 * @ret rc              Return status code
 */
static int smscusb_eeprom_read ( struct smscusb_device *smscusb,
                                 unsigned int e2p_base, unsigned int address,
                                 void *data, size_t len ) {
        uint8_t *bytes;
        int byte;

        /* Read bytes */
        for ( bytes = data ; len-- ; address++, bytes++ ) {
                byte = smscusb_eeprom_read_byte ( smscusb, e2p_base, address );
                if ( byte < 0 )
                        return byte;
                *bytes = byte;
        }

        return 0;
}

/**
 * Fetch MAC address from EEPROM
 *
 * @v smscusb           SMSC USB device
 * @v e2p_base          E2P register base
 * @ret rc              Return status code
 */
int smscusb_eeprom_fetch_mac ( struct smscusb_device *smscusb,
                               unsigned int e2p_base ) {
        struct net_device *netdev = smscusb->netdev;
        int rc;

        /* Read MAC address from EEPROM */
        if ( ( rc = smscusb_eeprom_read ( smscusb, e2p_base, SMSCUSB_EEPROM_MAC,
                                          netdev->hw_addr, ETH_ALEN ) ) != 0 )
                return rc;

        /* Check that EEPROM is physically present */
        if ( ! is_valid_ether_addr ( netdev->hw_addr ) ) {
                DBGC ( smscusb, "SMSCUSB %p has no EEPROM MAC (%s)\n",
                       smscusb, eth_ntoa ( netdev->hw_addr ) );
                return -ENODEV;
        }

        DBGC ( smscusb, "SMSCUSB %p using EEPROM MAC %s\n",
               smscusb, eth_ntoa ( netdev->hw_addr ) );
        return 0;
}

/******************************************************************************
 *
 * OTP access
 *
 ******************************************************************************
 */

/**
 * Power up OTP
 *
 * @v smscusb           SMSC USB device
 * @v otp_base          OTP register base
 * @ret rc              Return status code
 */
static int smscusb_otp_power_up ( struct smscusb_device *smscusb,
                                  unsigned int otp_base ) {
        uint32_t otp_power;
        unsigned int i;
        int rc;

        /* Power up OTP */
        if ( ( rc = smscusb_writel ( smscusb, ( otp_base + SMSCUSB_OTP_POWER ),
                                     0 ) ) != 0 )
                return rc;

        /* Wait for OTP_POWER_DOWN to become clear */
        for ( i = 0 ; i < SMSCUSB_OTP_MAX_WAIT_MS ; i++ ) {

                /* Read OTP_POWER and check OTP_POWER_DOWN */
                if ( ( rc = smscusb_readl ( smscusb,
                                            ( otp_base + SMSCUSB_OTP_POWER ),
                                            &otp_power ) ) != 0 )
                        return rc;
                if ( ! ( otp_power & SMSCUSB_OTP_POWER_DOWN ) )
                        return 0;

                /* Delay */
                mdelay ( 1 );
        }

        DBGC ( smscusb, "SMSCUSB %p timed out waiting for OTP power up\n",
               smscusb );
        return -ETIMEDOUT;
}

/**
 * Wait for OTP to become idle
 *
 * @v smscusb           SMSC USB device
 * @v otp_base          OTP register base
 * @ret rc              Return status code
 */
static int smscusb_otp_wait ( struct smscusb_device *smscusb,
                              unsigned int otp_base ) {
        uint32_t otp_status;
        unsigned int i;
        int rc;

        /* Wait for OTP_STATUS_BUSY to become clear */
        for ( i = 0 ; i < SMSCUSB_OTP_MAX_WAIT_MS ; i++ ) {

                /* Read OTP_STATUS and check OTP_STATUS_BUSY */
                if ( ( rc = smscusb_readl ( smscusb,
                                            ( otp_base + SMSCUSB_OTP_STATUS ),
                                            &otp_status ) ) != 0 )
                        return rc;
                if ( ! ( otp_status & SMSCUSB_OTP_STATUS_BUSY ) )
                        return 0;

                /* Delay */
                mdelay ( 1 );
        }

        DBGC ( smscusb, "SMSCUSB %p timed out waiting for OTP\n",
               smscusb );
        return -ETIMEDOUT;
}

/**
 * Read byte from OTP
 *
 * @v smscusb           SMSC USB device
 * @v otp_base          OTP register base
 * @v address           OTP address
 * @ret byte            Byte read, or negative error
 */
static int smscusb_otp_read_byte ( struct smscusb_device *smscusb,
                                   unsigned int otp_base,
                                   unsigned int address ) {
        uint8_t addrh = ( address >> 8 );
        uint8_t addrl = ( address >> 0 );
        uint32_t otp_data;
        int rc;

        /* Wait for OTP to become idle */
        if ( ( rc = smscusb_otp_wait ( smscusb, otp_base ) ) != 0 )
                return rc;

        /* Initiate read command */
        if ( ( rc = smscusb_writel ( smscusb, ( otp_base + SMSCUSB_OTP_ADDRH ),
                                     addrh ) ) != 0 )
                return rc;
        if ( ( rc = smscusb_writel ( smscusb, ( otp_base + SMSCUSB_OTP_ADDRL ),
                                     addrl ) ) != 0 )
                return rc;
        if ( ( rc = smscusb_writel ( smscusb, ( otp_base + SMSCUSB_OTP_CMD ),
                                     SMSCUSB_OTP_CMD_READ ) ) != 0 )
                return rc;
        if ( ( rc = smscusb_writel ( smscusb, ( otp_base + SMSCUSB_OTP_GO ),
                                     SMSCUSB_OTP_GO_GO ) ) != 0 )
                return rc;

        /* Wait for command to complete */
        if ( ( rc = smscusb_otp_wait ( smscusb, otp_base ) ) != 0 )
                return rc;

        /* Read OTP data */
        if ( ( rc = smscusb_readl ( smscusb, ( otp_base + SMSCUSB_OTP_DATA ),
                                    &otp_data ) ) != 0 )
                return rc;

        return SMSCUSB_OTP_DATA_GET ( otp_data );
}

/**
 * Read data from OTP
 *
 * @v smscusb           SMSC USB device
 * @v otp_base          OTP register base
 * @v address           OTP address
 * @v data              Data buffer
 * @v len               Length of data
 * @ret rc              Return status code
 */
static int smscusb_otp_read ( struct smscusb_device *smscusb,
                              unsigned int otp_base, unsigned int address,
                              void *data, size_t len ) {
        uint8_t *bytes;
        int byte;
        int rc;

        /* Power up OTP */
        if ( ( rc = smscusb_otp_power_up ( smscusb, otp_base ) ) != 0 )
                return rc;

        /* Read bytes */
        for ( bytes = data ; len-- ; address++, bytes++ ) {
                byte = smscusb_otp_read_byte ( smscusb, otp_base, address );
                if ( byte < 0 )
                        return byte;
                *bytes = byte;
        }

        return 0;
}

/**
 * Fetch MAC address from OTP
 *
 * @v smscusb           SMSC USB device
 * @v otp_base          OTP register base
 * @ret rc              Return status code
 */
int smscusb_otp_fetch_mac ( struct smscusb_device *smscusb,
                            unsigned int otp_base ) {
        struct net_device *netdev = smscusb->netdev;
        uint8_t signature;
        unsigned int address;
        int rc;

        /* Read OTP signature byte */
        if ( ( rc = smscusb_otp_read ( smscusb, otp_base, 0, &signature,
                                       sizeof ( signature ) ) ) != 0 )
                return rc;

        /* Determine location of MAC address */
        switch ( signature ) {
        case SMSCUSB_OTP_1_SIG:
                address = SMSCUSB_OTP_1_MAC;
                break;
        case SMSCUSB_OTP_2_SIG:
                address = SMSCUSB_OTP_2_MAC;
                break;
        default:
                DBGC ( smscusb, "SMSCUSB %p unknown OTP signature %#02x\n",
                       smscusb, signature );
                return -ENOTSUP;
        }

        /* Read MAC address from OTP */
        if ( ( rc = smscusb_otp_read ( smscusb, otp_base, address,
                                       netdev->hw_addr, ETH_ALEN ) ) != 0 )
                return rc;

        /* Check that OTP is valid */
        if ( ! is_valid_ether_addr ( netdev->hw_addr ) ) {
                DBGC ( smscusb, "SMSCUSB %p has no layout %#02x OTP MAC (%s)\n",
                       smscusb, signature, eth_ntoa ( netdev->hw_addr ) );
                return -ENODEV;
        }

        DBGC ( smscusb, "SMSCUSB %p using layout %#02x OTP MAC %s\n",
               smscusb, signature, eth_ntoa ( netdev->hw_addr ) );
        return 0;
}

/******************************************************************************
 *
 * Device tree
 *
 ******************************************************************************
 */

/**
 * Fetch MAC address from device tree
 *
 * @v smscusb           SMSC USB device
 * @ret rc              Return status code
 */
int smscusb_fdt_fetch_mac ( struct smscusb_device *smscusb ) {
        struct net_device *netdev = smscusb->netdev;
        unsigned int offset;
        int rc;

        /* Look for "ethernet[0]" alias */
        if ( ( rc = fdt_alias ( &sysfdt, "ethernet", &offset ) != 0 ) &&
             ( rc = fdt_alias ( &sysfdt, "ethernet0", &offset ) != 0 ) ) {
                return rc;
        }

        /* Fetch MAC address */
        if ( ( rc = fdt_mac ( &sysfdt, offset, netdev ) ) != 0 )
                return rc;

        DBGC ( smscusb, "SMSCUSB %p using FDT MAC %s\n",
               smscusb, eth_ntoa ( netdev->hw_addr ) );
        return 0;
}

/******************************************************************************
 *
 * MII access
 *
 ******************************************************************************
 */

/**
 * Wait for MII to become idle
 *
 * @v smscusb           SMSC USB device
 * @ret rc              Return status code
 */
static int smscusb_mii_wait ( struct smscusb_device *smscusb ) {
        unsigned int base = smscusb->mii_base;
        uint32_t mii_access;
        unsigned int i;
        int rc;

        /* Wait for MIIBZY to become clear */
        for ( i = 0 ; i < SMSCUSB_MII_MAX_WAIT_MS ; i++ ) {

                /* Read MII_ACCESS and check MIIBZY */
                if ( ( rc = smscusb_readl ( smscusb,
                                            ( base + SMSCUSB_MII_ACCESS ),
                                            &mii_access ) ) != 0 )
                        return rc;
                if ( ! ( mii_access & SMSCUSB_MII_ACCESS_MIIBZY ) )
                        return 0;

                /* Delay */
                mdelay ( 1 );
        }

        DBGC ( smscusb, "SMSCUSB %p timed out waiting for MII\n",
               smscusb );
        return -ETIMEDOUT;
}

/**
 * Read from MII register
 *
 * @v mdio              MII interface
 * @v phy               PHY address
 * @v reg               Register address
 * @ret value           Data read, or negative error
 */
static int smscusb_mii_read ( struct mii_interface *mdio,
                              unsigned int phy __unused, unsigned int reg ) {
        struct smscusb_device *smscusb =
                container_of ( mdio, struct smscusb_device, mdio );
        unsigned int base = smscusb->mii_base;
        uint32_t mii_access;
        uint32_t mii_data;
        int rc;

        /* Wait for MII to become idle */
        if ( ( rc = smscusb_mii_wait ( smscusb ) ) != 0 )
                return rc;

        /* Initiate read command */
        mii_access = ( SMSCUSB_MII_ACCESS_PHY_ADDRESS |
                       SMSCUSB_MII_ACCESS_MIIRINDA ( reg ) |
                       SMSCUSB_MII_ACCESS_MIIBZY );
        if ( ( rc = smscusb_writel ( smscusb, ( base + SMSCUSB_MII_ACCESS ),
                                     mii_access ) ) != 0 )
                return rc;

        /* Wait for command to complete */
        if ( ( rc = smscusb_mii_wait ( smscusb ) ) != 0 )
                return rc;

        /* Read MII data */
        if ( ( rc = smscusb_readl ( smscusb, ( base + SMSCUSB_MII_DATA ),
                                    &mii_data ) ) != 0 )
                return rc;

        return SMSCUSB_MII_DATA_GET ( mii_data );
}

/**
 * Write to MII register
 *
 * @v mdio              MII interface
 * @v phy               PHY address
 * @v reg               Register address
 * @v data              Data to write
 * @ret rc              Return status code
 */
static int smscusb_mii_write ( struct mii_interface *mdio,
                               unsigned int phy __unused, unsigned int reg,
                               unsigned int data ) {
        struct smscusb_device *smscusb =
                container_of ( mdio, struct smscusb_device, mdio );
        unsigned int base = smscusb->mii_base;
        uint32_t mii_access;
        uint32_t mii_data;
        int rc;

        /* Wait for MII to become idle */
        if ( ( rc = smscusb_mii_wait ( smscusb ) ) != 0 )
                return rc;

        /* Write MII data */
        mii_data = SMSCUSB_MII_DATA_SET ( data );
        if ( ( rc = smscusb_writel ( smscusb, ( base + SMSCUSB_MII_DATA ),
                                     mii_data ) ) != 0 )
                return rc;

        /* Initiate write command */
        mii_access = ( SMSCUSB_MII_ACCESS_PHY_ADDRESS |
                       SMSCUSB_MII_ACCESS_MIIRINDA ( reg ) |
                       SMSCUSB_MII_ACCESS_MIIWNR |
                       SMSCUSB_MII_ACCESS_MIIBZY );
        if ( ( rc = smscusb_writel ( smscusb, ( base + SMSCUSB_MII_ACCESS ),
                                     mii_access ) ) != 0 )
                return rc;

        /* Wait for command to complete */
        if ( ( rc = smscusb_mii_wait ( smscusb ) ) != 0 )
                return rc;

        return 0;
}

/** MII operations */
struct mii_operations smscusb_mii_operations = {
        .read = smscusb_mii_read,
        .write = smscusb_mii_write,
};

/**
 * Check link status
 *
 * @v smscusb           SMSC USB device
 * @ret rc              Return status code
 */
int smscusb_mii_check_link ( struct smscusb_device *smscusb ) {
        struct net_device *netdev = smscusb->netdev;
        int intr;
        int rc;

        /* Read PHY interrupt source */
        intr = mii_read ( &smscusb->mii, smscusb->phy_source );
        if ( intr < 0 ) {
                rc = intr;
                DBGC ( smscusb, "SMSCUSB %p could not get PHY interrupt "
                       "source: %s\n", smscusb, strerror ( rc ) );
                return rc;
        }

        /* Acknowledge PHY interrupt */
        if ( ( rc = mii_write ( &smscusb->mii, smscusb->phy_source,
                                intr ) ) != 0 ) {
                DBGC ( smscusb, "SMSCUSB %p could not acknowledge PHY "
                       "interrupt: %s\n", smscusb, strerror ( rc ) );
                return rc;
        }

        /* Check link status */
        if ( ( rc = mii_check_link ( &smscusb->mii, netdev ) ) != 0 ) {
                DBGC ( smscusb, "SMSCUSB %p could not check link: %s\n",
                       smscusb, strerror ( rc ) );
                return rc;
        }

        DBGC ( smscusb, "SMSCUSB %p link %s (intr %#04x)\n",
               smscusb, ( netdev_link_ok ( netdev ) ? "up" : "down" ), intr );
        return 0;
}

/**
 * Enable PHY interrupts and update link status
 *
 * @v smscusb           SMSC USB device
 * @v phy_mask          PHY interrupt mask register
 * @v intrs             PHY interrupts to enable
 * @ret rc              Return status code
 */
int smscusb_mii_open ( struct smscusb_device *smscusb,
                       unsigned int phy_mask, unsigned int intrs ) {
        int rc;

        /* Enable PHY interrupts */
        if ( ( rc = mii_write ( &smscusb->mii, phy_mask, intrs ) ) != 0 ) {
                DBGC ( smscusb, "SMSCUSB %p could not set PHY interrupt "
                       "mask: %s\n", smscusb, strerror ( rc ) );
                return rc;
        }

        /* Update link status */
        smscusb_mii_check_link ( smscusb );

        return 0;
}

/******************************************************************************
 *
 * Receive filtering
 *
 ******************************************************************************
 */

/**
 * Set receive address
 *
 * @v smscusb           SMSC USB device
 * @v addr_base         Receive address register base
 * @ret rc              Return status code
 */
int smscusb_set_address ( struct smscusb_device *smscusb,
                          unsigned int addr_base ) {
        struct net_device *netdev = smscusb->netdev;
        union smscusb_mac mac;
        int rc;

        /* Copy MAC address */
        memset ( &mac, 0, sizeof ( mac ) );
        memcpy ( mac.raw, netdev->ll_addr, ETH_ALEN );

        /* Write MAC address high register */
        if ( ( rc = smscusb_raw_writel ( smscusb,
                                         ( addr_base + SMSCUSB_RX_ADDRH ),
                                         mac.addr.h ) ) != 0 )
                return rc;

        /* Write MAC address low register */
        if ( ( rc = smscusb_raw_writel ( smscusb,
                                         ( addr_base + SMSCUSB_RX_ADDRL ),
                                         mac.addr.l ) ) != 0 )
                return rc;

        return 0;
}

/**
 * Set receive filter
 *
 * @v smscusb           SMSC USB device
 * @v filt_base         Receive filter register base
 * @ret rc              Return status code
 */
int smscusb_set_filter ( struct smscusb_device *smscusb,
                         unsigned int filt_base ) {
        struct net_device *netdev = smscusb->netdev;
        union smscusb_mac mac;
        int rc;

        /* Copy MAC address */
        memset ( &mac, 0, sizeof ( mac ) );
        memcpy ( mac.raw, netdev->ll_addr, ETH_ALEN );
        mac.addr.h |= cpu_to_le32 ( SMSCUSB_ADDR_FILTH_VALID );

        /* Write MAC address perfect filter high register */
        if ( ( rc = smscusb_raw_writel ( smscusb,
                                         ( filt_base + SMSCUSB_ADDR_FILTH(0) ),
                                         mac.addr.h ) ) != 0 )
                return rc;

        /* Write MAC address perfect filter low register */
        if ( ( rc = smscusb_raw_writel ( smscusb,
                                         ( filt_base + SMSCUSB_ADDR_FILTL(0) ),
                                         mac.addr.l ) ) != 0 )
                return rc;

        return 0;
}

/******************************************************************************
 *
 * Endpoint operations
 *
 ******************************************************************************
 */

/**
 * Complete interrupt transfer
 *
 * @v ep                USB endpoint
 * @v iobuf             I/O buffer
 * @v rc                Completion status code
 */
static void smscusb_intr_complete ( struct usb_endpoint *ep,
                                    struct io_buffer *iobuf, int rc ) {
        struct smscusb_device *smscusb =
                container_of ( ep, struct smscusb_device, usbnet.intr );
        struct net_device *netdev = smscusb->netdev;
        struct smscusb_interrupt *intr;

        /* Profile completions */
        profile_start ( &smscusb_intr_profiler );

        /* Ignore packets cancelled when the endpoint closes */
        if ( ! ep->open )
                goto done;

        /* Record USB errors against the network device */
        if ( rc != 0 ) {
                DBGC ( smscusb, "SMSCUSB %p interrupt failed: %s\n",
                       smscusb, strerror ( rc ) );
                DBGC_HDA ( smscusb, 0, iobuf->data, iob_len ( iobuf ) );
                netdev_rx_err ( netdev, NULL, rc );
                goto done;
        }

        /* Extract interrupt data */
        if ( iob_len ( iobuf ) != sizeof ( *intr ) ) {
                DBGC ( smscusb, "SMSCUSB %p malformed interrupt\n",
                       smscusb );
                DBGC_HDA ( smscusb, 0, iobuf->data, iob_len ( iobuf ) );
                netdev_rx_err ( netdev, NULL, rc );
                goto done;
        }
        intr = iobuf->data;

        /* Record interrupt status */
        smscusb->int_sts = le32_to_cpu ( intr->int_sts );
        profile_stop ( &smscusb_intr_profiler );

 done:
        /* Free I/O buffer */
        free_iob ( iobuf );
}

/** Interrupt endpoint operations */
struct usb_endpoint_driver_operations smscusb_intr_operations = {
        .complete = smscusb_intr_complete,
};

/**
 * Complete bulk OUT transfer
 *
 * @v ep                USB endpoint
 * @v iobuf             I/O buffer
 * @v rc                Completion status code
 */
static void smscusb_out_complete ( struct usb_endpoint *ep,
                                   struct io_buffer *iobuf, int rc ) {
        struct smscusb_device *smscusb =
                container_of ( ep, struct smscusb_device, usbnet.out );
        struct net_device *netdev = smscusb->netdev;

        /* Report TX completion */
        netdev_tx_complete_err ( netdev, iobuf, rc );
}

/** Bulk OUT endpoint operations */
struct usb_endpoint_driver_operations smscusb_out_operations = {
        .complete = smscusb_out_complete,
};