cdev.c

/******************************************************************************
 *
 *  $Id$
 *
 *  Copyright (C) 2006-2008  Florian Pose, Ingenieurgemeinschaft IgH
 *
 *  This file is part of the IgH EtherCAT Master.
 *
 *  The IgH EtherCAT Master is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License version 2, as
 *  published by the Free Software Foundation.
 *
 *  The IgH EtherCAT Master 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 the IgH EtherCAT Master; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 *  ---
 *
 *  The license mentioned above concerns the source code only. Using the
 *  EtherCAT technology and brand is only permitted in compliance with the
 *  industrial property and similar rights of Beckhoff Automation GmbH.
 *
 *****************************************************************************/

/**
   \file
   EtherCAT master character device.
*/

/*****************************************************************************/

#include <linux/module.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>

#include "cdev.h"
#include "master.h"
#include "slave_config.h"
#include "voe_handler.h"
#include "ethernet.h"
#include "ioctl.h"

/** Set to 1 to enable ioctl() command debugging.
 */
#define DEBUG_IOCTL 0

/** Set to 1 to enable ioctl() latency warnings.
 *
 * Requires CPU timestamp counter!
 */
#define DEBUG_LATENCY 0

/*****************************************************************************/

static int eccdev_open(struct inode *, struct file *);
static int eccdev_release(struct inode *, struct file *);
static long eccdev_ioctl(struct file *, unsigned int, unsigned long);
static int eccdev_mmap(struct file *, struct vm_area_struct *);

/** This is the kernel version from which the .fault member of the
 * vm_operations_struct is usable.
 */
#define PAGE_FAULT_VERSION KERNEL_VERSION(2, 6, 23)

#if LINUX_VERSION_CODE >= PAGE_FAULT_VERSION
static int eccdev_vma_fault(struct vm_area_struct *, struct vm_fault *);
#else
static struct page *eccdev_vma_nopage(
        struct vm_area_struct *, unsigned long, int *);
#endif

/*****************************************************************************/

/** File operation callbacks for the EtherCAT character device.
 */
static struct file_operations eccdev_fops = {
    .owner          = THIS_MODULE,
    .open           = eccdev_open,
    .release        = eccdev_release,
    .unlocked_ioctl = eccdev_ioctl,
    .mmap           = eccdev_mmap
};

/** Callbacks for a virtual memory area retrieved with ecdevc_mmap().
 */
struct vm_operations_struct eccdev_vm_ops = {
#if LINUX_VERSION_CODE >= PAGE_FAULT_VERSION
    .fault = eccdev_vma_fault
#else
    .nopage = eccdev_vma_nopage
#endif
};

/*****************************************************************************/

/** Private data structure for file handles.
 */
typedef struct {
    ec_cdev_t *cdev; /**< Character device. */
    unsigned int requested; /**< Master wac requested via this file handle. */
    uint8_t *process_data; /**< Total process data area. */
    size_t process_data_size; /**< Size of the \a process_data. */
} ec_cdev_priv_t;

/*****************************************************************************/

/** Constructor.
 * 
 * \return 0 in case of success, else < 0
 */
int ec_cdev_init(
        ec_cdev_t *cdev, /**< EtherCAT master character device. */
        ec_master_t *master, /**< Parent master. */
        dev_t dev_num /**< Device number. */
        )
{
    int ret;

    cdev->master = master;

    cdev_init(&cdev->cdev, &eccdev_fops);
    cdev->cdev.owner = THIS_MODULE;

    ret = cdev_add(&cdev->cdev,
            MKDEV(MAJOR(dev_num), master->index), 1);
    if (ret) {
        EC_MASTER_ERR(master, "Failed to add character device!\n");
    }

    return ret;
}

/*****************************************************************************/

/** Destructor.
 */
void ec_cdev_clear(ec_cdev_t *cdev /**< EtherCAT XML device */)
{
    cdev_del(&cdev->cdev);
}

/*****************************************************************************/

/** Copies a string to an ioctl structure.
 */
void ec_cdev_strcpy(
        char *target, /**< Target. */
        const char *source /**< Source. */
        )
{
    if (source) {
        strncpy(target, source, EC_IOCTL_STRING_SIZE);
        target[EC_IOCTL_STRING_SIZE - 1] = 0;
    } else {
        target[0] = 0;
    }
}

/*****************************************************************************/

/** Get module information.
 */
int ec_cdev_ioctl_module(
        unsigned long arg /**< Userspace address to store the results. */
        )
{
    ec_ioctl_module_t data;

    data.ioctl_version_magic = EC_IOCTL_VERSION_MAGIC;
    data.master_count = ec_master_count();

    if (copy_to_user((void __user *) arg, &data, sizeof(data)))
        return -EFAULT;

    return 0;
}

/*****************************************************************************/

/** Get master information.
 */
int ec_cdev_ioctl_master(
        ec_master_t *master, /**< EtherCAT master. */
        unsigned long arg /**< Userspace address to store the results. */
        )
{
    ec_ioctl_master_t data;
    unsigned int i;

    if (down_interruptible(&master->master_sem))
        return -EINTR;
    data.slave_count = master->slave_count;
    data.config_count = ec_master_config_count(master);
    data.domain_count = ec_master_domain_count(master);
#ifdef EC_EOE
    data.eoe_handler_count = ec_master_eoe_handler_count(master);
#endif
    data.phase = (uint8_t) master->phase;
    data.active = (uint8_t) master->active;
    data.scan_busy = master->scan_busy;
    up(&master->master_sem);

    if (down_interruptible(&master->device_sem))
        return -EINTR;

    if (master->main_device.dev) {
        memcpy(data.devices[0].address,
                master->main_device.dev->dev_addr, ETH_ALEN);
    } else {
        memcpy(data.devices[0].address, master->main_mac, ETH_ALEN); 
    }
    data.devices[0].attached = master->main_device.dev ? 1 : 0;
    data.devices[0].link_state = master->main_device.link_state ? 1 : 0;
    data.devices[0].tx_count = master->main_device.tx_count;
    data.devices[0].rx_count = master->main_device.rx_count;
    data.devices[0].tx_bytes = master->main_device.tx_bytes;
    data.devices[0].tx_errors = master->main_device.tx_errors;
    for (i = 0; i < EC_RATE_COUNT; i++) {
        data.devices[0].tx_frame_rates[i] =
            master->main_device.tx_frame_rates[i];
        data.devices[0].tx_byte_rates[i] =
            master->main_device.tx_byte_rates[i];
        data.devices[0].loss_rates[i] = master->main_device.loss_rates[i];
    }

    if (master->backup_device.dev) {
        memcpy(data.devices[1].address,
                master->backup_device.dev->dev_addr, ETH_ALEN); 
    } else {
        memcpy(data.devices[1].address, master->backup_mac, ETH_ALEN); 
    }
    data.devices[1].attached = master->backup_device.dev ? 1 : 0;
    data.devices[1].link_state = master->backup_device.link_state ? 1 : 0;
    data.devices[1].tx_count = master->backup_device.tx_count;
    data.devices[1].rx_count = master->backup_device.rx_count;
    data.devices[1].tx_bytes = master->backup_device.tx_bytes;
    data.devices[1].tx_errors = master->backup_device.tx_errors;
    for (i = 0; i < EC_RATE_COUNT; i++) {
        data.devices[1].tx_frame_rates[i] =
            master->backup_device.tx_frame_rates[i];
        data.devices[1].tx_byte_rates[i] =
            master->backup_device.tx_byte_rates[i];
        data.devices[1].loss_rates[i] = master->backup_device.loss_rates[i];
    }

    up(&master->device_sem);

    data.app_time = master->app_time;
    data.ref_clock =
        master->dc_ref_clock ? master->dc_ref_clock->ring_position : 0xffff;

    if (copy_to_user((void __user *) arg, &data, sizeof(data)))
        return -EFAULT;

    return 0;
}

/*****************************************************************************/

/** Get slave information.
 */
int ec_cdev_ioctl_slave(
        ec_master_t *master, /**< EtherCAT master. */
        unsigned long arg /**< Userspace address to store the results. */
        )
{
    ec_ioctl_slave_t data;
    const ec_slave_t *slave;
    int i;

    if (copy_from_user(&data, (void __user *) arg, sizeof(data))) {
        return -EFAULT;
    }

    if (down_interruptible(&master->master_sem))
        return -EINTR;

    if (!(slave = ec_master_find_slave_const(
                    master, 0, data.position))) {
        up(&master->master_sem);
        EC_MASTER_ERR(master, "Slave %u does not exist!\n", data.position);
        return -EINVAL;
    }

    data.vendor_id = slave->sii.vendor_id;
    data.product_code = slave->sii.product_code;
    data.revision_number = slave->sii.revision_number;
    data.serial_number = slave->sii.serial_number;
    data.alias = slave->effective_alias;
    data.boot_rx_mailbox_offset = slave->sii.boot_rx_mailbox_offset;
    data.boot_rx_mailbox_size = slave->sii.boot_rx_mailbox_size;
    data.boot_tx_mailbox_offset = slave->sii.boot_tx_mailbox_offset;
    data.boot_tx_mailbox_size = slave->sii.boot_tx_mailbox_size;
    data.std_rx_mailbox_offset = slave->sii.std_rx_mailbox_offset;
    data.std_rx_mailbox_size = slave->sii.std_rx_mailbox_size;
    data.std_tx_mailbox_offset = slave->sii.std_tx_mailbox_offset;
    data.std_tx_mailbox_size = slave->sii.std_tx_mailbox_size;
    data.mailbox_protocols = slave->sii.mailbox_protocols;
    data.has_general_category = slave->sii.has_general;
    data.coe_details = slave->sii.coe_details;
    data.general_flags = slave->sii.general_flags;
    data.current_on_ebus = slave->sii.current_on_ebus;
    for (i = 0; i < EC_MAX_PORTS; i++) {
        data.ports[i].desc = slave->ports[i].desc;
        data.ports[i].link.link_up = slave->ports[i].link.link_up;
        data.ports[i].link.loop_closed = slave->ports[i].link.loop_closed;
        data.ports[i].link.signal_detected =
            slave->ports[i].link.signal_detected;
        data.ports[i].receive_time = slave->ports[i].receive_time;
        if (slave->ports[i].next_slave) {
            data.ports[i].next_slave =
                slave->ports[i].next_slave->ring_position;
        } else {
            data.ports[i].next_slave = 0xffff;
        }
        data.ports[i].delay_to_next_dc = slave->ports[i].delay_to_next_dc;
    }
    data.fmmu_bit = slave->base_fmmu_bit_operation;
    data.dc_supported = slave->base_dc_supported;
    data.dc_range = slave->base_dc_range;
    data.has_dc_system_time = slave->has_dc_system_time;
    data.transmission_delay = slave->transmission_delay;
    data.al_state = slave->current_state;
    data.error_flag = slave->error_flag;

    data.sync_count = slave->sii.sync_count;
    data.sdo_count = ec_slave_sdo_count(slave);
    data.sii_nwords = slave->sii_nwords;
    ec_cdev_strcpy(data.group, slave->sii.group);
    ec_cdev_strcpy(data.image, slave->sii.image);
    ec_cdev_strcpy(data.order, slave->sii.order);
    ec_cdev_strcpy(data.name, slave->sii.name);

    up(&master->master_sem);

    if (copy_to_user((void __user *) arg, &data, sizeof(data)))
        return -EFAULT;

    return 0;
}

/*****************************************************************************/

/** Get slave sync manager information.
 */
int ec_cdev_ioctl_slave_sync(
        ec_master_t *master, /**< EtherCAT master. */
        unsigned long arg /**< Userspace address to store the results. */
        )
{
    ec_ioctl_slave_sync_t data;
    const ec_slave_t *slave;
    const ec_sync_t *sync;

    if (copy_from_user(&data, (void __user *) arg, sizeof(data))) {
        return -EFAULT;
    }

    if (down_interruptible(&master->master_sem))
        return -EINTR;

    if (!(slave = ec_master_find_slave_const(
                    master, 0, data.slave_position))) {
        up(&master->master_sem);
        EC_MASTER_ERR(master, "Slave %u does not exist!\n",
                data.slave_position);
        return -EINVAL;
    }

    if (data.sync_index >= slave->sii.sync_count) {
        up(&master->master_sem);
        EC_SLAVE_ERR(slave, "Sync manager %u does not exist!\n",
                data.sync_index);
        return -EINVAL;
    }

    sync = &slave->sii.syncs[data.sync_index];

    data.physical_start_address = sync->physical_start_address;
    data.default_size = sync->default_length;
    data.control_register = sync->control_register;
    data.enable = sync->enable;
    data.pdo_count = ec_pdo_list_count(&sync->pdos);

    up(&master->master_sem);

    if (copy_to_user((void __user *) arg, &data, sizeof(data)))
        return -EFAULT;

    return 0;
}

/*****************************************************************************/

/** Get slave sync manager PDO information.
 */
int ec_cdev_ioctl_slave_sync_pdo(
        ec_master_t *master, /**< EtherCAT master. */
        unsigned long arg /**< Userspace address to store the results. */
        )
{
    ec_ioctl_slave_sync_pdo_t data;
    const ec_slave_t *slave;
    const ec_sync_t *sync;
    const ec_pdo_t *pdo;

    if (copy_from_user(&data, (void __user *) arg, sizeof(data))) {
        return -EFAULT;
    }

    if (down_interruptible(&master->master_sem))
        return -EINTR;

    if (!(slave = ec_master_find_slave_const(
                    master, 0, data.slave_position))) {
        up(&master->master_sem);
        EC_MASTER_ERR(master, "Slave %u does not exist!\n",
                data.slave_position);
        return -EINVAL;
    }

    if (data.sync_index >= slave->sii.sync_count) {
        up(&master->master_sem);
        EC_SLAVE_ERR(slave, "Sync manager %u does not exist!\n",
                data.sync_index);
        return -EINVAL;
    }

    sync = &slave->sii.syncs[data.sync_index];
    if (!(pdo = ec_pdo_list_find_pdo_by_pos_const(
                    &sync->pdos, data.pdo_pos))) {
        up(&master->master_sem);
        EC_SLAVE_ERR(slave, "Sync manager %u does not contain a PDO with "
                "position %u!\n", data.sync_index, data.pdo_pos);
        return -EINVAL;
    }

    data.index = pdo->index;
    data.entry_count = ec_pdo_entry_count(pdo);
    ec_cdev_strcpy(data.name, pdo->name);

    up(&master->master_sem);

    if (copy_to_user((void __user *) arg, &data, sizeof(data)))
        return -EFAULT;

    return 0;
}

/*****************************************************************************/

/** Get slave sync manager PDO entry information.
 */
int ec_cdev_ioctl_slave_sync_pdo_entry(
        ec_master_t *master, /**< EtherCAT master. */
        unsigned long arg /**< Userspace address to store the results. */
        )
{
    ec_ioctl_slave_sync_pdo_entry_t data;
    const ec_slave_t *slave;
    const ec_sync_t *sync;
    const ec_pdo_t *pdo;
    const ec_pdo_entry_t *entry;

    if (copy_from_user(&data, (void __user *) arg, sizeof(data))) {
        return -EFAULT;
    }

    if (down_interruptible(&master->master_sem))
        return -EINTR;

    if (!(slave = ec_master_find_slave_const(
                    master, 0, data.slave_position))) {
        up(&master->master_sem);
        EC_MASTER_ERR(master, "Slave %u does not exist!\n",
                data.slave_position);
        return -EINVAL;
    }

    if (data.sync_index >= slave->sii.sync_count) {
        up(&master->master_sem);
        EC_SLAVE_ERR(slave, "Sync manager %u does not exist!\n",
                data.sync_index);
        return -EINVAL;
    }

    sync = &slave->sii.syncs[data.sync_index];
    if (!(pdo = ec_pdo_list_find_pdo_by_pos_const(
                    &sync->pdos, data.pdo_pos))) {
        up(&master->master_sem);
        EC_SLAVE_ERR(slave, "Sync manager %u does not contain a PDO with "
                "position %u!\n", data.sync_index, data.pdo_pos);
        return -EINVAL;
    }

    if (!(entry = ec_pdo_find_entry_by_pos_const(
                    pdo, data.entry_pos))) {
        up(&master->master_sem);
        EC_SLAVE_ERR(slave, "PDO 0x%04X does not contain an entry with "
                "position %u!\n", data.pdo_pos, data.entry_pos);
        return -EINVAL;
    }

    data.index = entry->index;
    data.subindex = entry->subindex;
    data.bit_length = entry->bit_length;
    ec_cdev_strcpy(data.name, entry->name);

    up(&master->master_sem);

    if (copy_to_user((void __user *) arg, &data, sizeof(data)))
        return -EFAULT;

    return 0;
}

/*****************************************************************************/

/** Get domain information.
 */
int ec_cdev_ioctl_domain(
        ec_master_t *master, /**< EtherCAT master. */
        unsigned long arg /**< Userspace address to store the results. */
        )
{
    ec_ioctl_domain_t data;
    const ec_domain_t *domain;

    if (copy_from_user(&data, (void __user *) arg, sizeof(data))) {
        return -EFAULT;
    }

    if (down_interruptible(&master->master_sem))
        return -EINTR;

    if (!(domain = ec_master_find_domain_const(master, data.index))) {
        up(&master->master_sem);
        EC_MASTER_ERR(master, "Domain %u does not exist!\n", data.index);
        return -EINVAL;
    }

    data.data_size = domain->data_size;
    data.logical_base_address = domain->logical_base_address;
    data.working_counter = domain->working_counter;
    data.expected_working_counter = domain->expected_working_counter;
    data.fmmu_count = ec_domain_fmmu_count(domain);

    up(&master->master_sem);

    if (copy_to_user((void __user *) arg, &data, sizeof(data)))
        return -EFAULT;

    return 0;
}

/*****************************************************************************/

/** Get domain FMMU information.
 */
int ec_cdev_ioctl_domain_fmmu(
        ec_master_t *master, /**< EtherCAT master. */
        unsigned long arg /**< Userspace address to store the results. */
        )
{
    ec_ioctl_domain_fmmu_t data;
    const ec_domain_t *domain;
    const ec_fmmu_config_t *fmmu;

    if (copy_from_user(&data, (void __user *) arg, sizeof(data))) {
        return -EFAULT;
    }

    if (down_interruptible(&master->master_sem))
        return -EINTR;

    if (!(domain = ec_master_find_domain_const(master, data.domain_index))) {
        up(&master->master_sem);
        EC_MASTER_ERR(master, "Domain %u does not exist!\n",
                data.domain_index);
        return -EINVAL;
    }

    if (!(fmmu = ec_domain_find_fmmu(domain, data.fmmu_index))) {
        up(&master->master_sem);
        EC_MASTER_ERR(master, "Domain %u has less than %u"
                " fmmu configurations.\n",
                data.domain_index, data.fmmu_index + 1);
        return -EINVAL;
    }

    data.slave_config_alias = fmmu->sc->alias;
    data.slave_config_position = fmmu->sc->position;
    data.sync_index = fmmu->sync_index;
    data.dir = fmmu->dir;
    data.logical_address = fmmu->logical_start_address;
    data.data_size = fmmu->data_size;

    up(&master->master_sem);

    if (copy_to_user((void __user *) arg, &data, sizeof(data)))
        return -EFAULT;

    return 0;
}

/*****************************************************************************/

/** Get domain data.
 */
int ec_cdev_ioctl_domain_data(
        ec_master_t *master, /**< EtherCAT master. */
        unsigned long arg /**< Userspace address to store the results. */
        )
{
    ec_ioctl_domain_data_t data;
    const ec_domain_t *domain;

    if (copy_from_user(&data, (void __user *) arg, sizeof(data))) {
        return -EFAULT;
    }

    if (down_interruptible(&master->master_sem))
        return -EINTR;

    if (!(domain = ec_master_find_domain_const(master, data.domain_index))) {
        up(&master->master_sem);
        EC_MASTER_ERR(master, "Domain %u does not exist!\n",
                data.domain_index);
        return -EINVAL;
    }

    if (domain->data_size != data.data_size) {
        up(&master->master_sem);
        EC_MASTER_ERR(master, "Data size mismatch %u/%zu!\n",
                data.data_size, domain->data_size);
        return -EFAULT;
    }

    if (copy_to_user((void __user *) data.target, domain->data,
                domain->data_size)) {
        up(&master->master_sem);
        return -EFAULT;
    }

    up(&master->master_sem);
    return 0;
}

/*****************************************************************************/

/** Set master debug level.
 */
int ec_cdev_ioctl_master_debug(
        ec_master_t *master, /**< EtherCAT master. */
        unsigned long arg /**< ioctl() argument. */
        )
{
    return ec_master_debug_level(master, (unsigned int) arg);
}

/*****************************************************************************/

/** Issue a bus scan.
 */
int ec_cdev_ioctl_master_rescan(
        ec_master_t *master, /**< EtherCAT master. */
        unsigned long arg /**< ioctl() argument. */
        )
{
    master->fsm.rescan_required = 1;
    return 0;
}

/*****************************************************************************/

/** Set slave state.
 */
int ec_cdev_ioctl_slave_state(
        ec_master_t *master, /**< EtherCAT master. */
        unsigned long arg /**< ioctl() argument. */
        )
{
    ec_ioctl_slave_state_t data;
    ec_slave_t *slave;

    if (copy_from_user(&data, (void __user *) arg, sizeof(data))) {
        return -EFAULT;
    }

    if (down_interruptible(&master->master_sem))
        return -EINTR;

    if (!(slave = ec_master_find_slave(
                    master, 0, data.slave_position))) {
        up(&master->master_sem);
        EC_MASTER_ERR(master, "Slave %u does not exist!\n",
                data.slave_position);
        return -EINVAL;
    }

    ec_slave_request_state(slave, data.al_state);

    up(&master->master_sem);
    return 0;
}

/*****************************************************************************/

/** Get slave SDO information.
 */
int ec_cdev_ioctl_slave_sdo(
        ec_master_t *master, /**< EtherCAT master. */
        unsigned long arg /**< ioctl() argument. */
        )
{
    ec_ioctl_slave_sdo_t data;
    const ec_slave_t *slave;
    const ec_sdo_t *sdo;

    if (copy_from_user(&data, (void __user *) arg, sizeof(data))) {
        return -EFAULT;
    }

    if (down_interruptible(&master->master_sem))
        return -EINTR;

    if (!(slave = ec_master_find_slave_const(
                    master, 0, data.slave_position))) {
        up(&master->master_sem);
        EC_MASTER_ERR(master, "Slave %u does not exist!\n",
                data.slave_position);
        return -EINVAL;
    }

    if (!(sdo = ec_slave_get_sdo_by_pos_const(
                    slave, data.sdo_position))) {
        up(&master->master_sem);
        EC_SLAVE_ERR(slave, "SDO %u does not exist!\n", data.sdo_position);
        return -EINVAL;
    }

    data.sdo_index = sdo->index;
    data.max_subindex = sdo->max_subindex;
    ec_cdev_strcpy(data.name, sdo->name);

    up(&master->master_sem);

    if (copy_to_user((void __user *) arg, &data, sizeof(data)))
        return -EFAULT;

    return 0;
}

/*****************************************************************************/

/** Get slave SDO entry information.
 */
int ec_cdev_ioctl_slave_sdo_entry(
        ec_master_t *master, /**< EtherCAT master. */
        unsigned long arg /**< ioctl() argument. */
        )
{
    ec_ioctl_slave_sdo_entry_t data;
    const ec_slave_t *slave;
    const ec_sdo_t *sdo;
    const ec_sdo_entry_t *entry;

    if (copy_from_user(&data, (void __user *) arg, sizeof(data))) {
        return -EFAULT;
    }

    if (down_interruptible(&master->master_sem))
        return -EINTR;

    if (!(slave = ec_master_find_slave_const(
                    master, 0, data.slave_position))) {
        up(&master->master_sem);
        EC_MASTER_ERR(master, "Slave %u does not exist!\n",
                data.slave_position);
        return -EINVAL;
    }

    if (data.sdo_spec <= 0) {
        if (!(sdo = ec_slave_get_sdo_by_pos_const(
                        slave, -data.sdo_spec))) {
            up(&master->master_sem);
            EC_SLAVE_ERR(slave, "SDO %u does not exist!\n", -data.sdo_spec);
            return -EINVAL;
        }
    } else {
        if (!(sdo = ec_slave_get_sdo_const(
                        slave, data.sdo_spec))) {
            up(&master->master_sem);
            EC_SLAVE_ERR(slave, "SDO 0x%04X does not exist!\n",
                    data.sdo_spec);
            return -EINVAL;
        }
    }

    if (!(entry = ec_sdo_get_entry_const(
                    sdo, data.sdo_entry_subindex))) {
        up(&master->master_sem);
        EC_SLAVE_ERR(slave, "SDO entry 0x%04X:%02X does not exist!\n",
                sdo->index, data.sdo_entry_subindex);
        return -EINVAL;
    }

    data.data_type = entry->data_type;
    data.bit_length = entry->bit_length;
    data.read_access[EC_SDO_ENTRY_ACCESS_PREOP] =
        entry->read_access[EC_SDO_ENTRY_ACCESS_PREOP];
    data.read_access[EC_SDO_ENTRY_ACCESS_SAFEOP] =
        entry->read_access[EC_SDO_ENTRY_ACCESS_SAFEOP];
    data.read_access[EC_SDO_ENTRY_ACCESS_OP] =
        entry->read_access[EC_SDO_ENTRY_ACCESS_OP];
    data.write_access[EC_SDO_ENTRY_ACCESS_PREOP] =
        entry->write_access[EC_SDO_ENTRY_ACCESS_PREOP];
    data.write_access[EC_SDO_ENTRY_ACCESS_SAFEOP] =
        entry->write_access[EC_SDO_ENTRY_ACCESS_SAFEOP];
    data.write_access[EC_SDO_ENTRY_ACCESS_OP] =
        entry->write_access[EC_SDO_ENTRY_ACCESS_OP];
    ec_cdev_strcpy(data.description, entry->description);

    up(&master->master_sem);

    if (copy_to_user((void __user *) arg, &data, sizeof(data)))
        return -EFAULT;

    return 0;
}

/*****************************************************************************/

/** Upload SDO.
 */
int ec_cdev_ioctl_slave_sdo_upload(
        ec_master_t *master, /**< EtherCAT master. */
        unsigned long arg /**< ioctl() argument. */
        )
{
    ec_ioctl_slave_sdo_upload_t data;
    uint8_t *target;
    int ret;

    if (copy_from_user(&data, (void __user *) arg, sizeof(data))) {
        return -EFAULT;
    }

    if (!(target = kmalloc(data.target_size, GFP_KERNEL))) {
        EC_MASTER_ERR(master, "Failed to allocate %u bytes"
                " for SDO upload.\n", data.target_size);
        return -ENOMEM;
    }

    ret = ecrt_master_sdo_upload(master, data.slave_position,
            data.sdo_index, data.sdo_entry_subindex, target,
            data.target_size, &data.data_size, &data.abort_code);

    if (!ret) {
        if (copy_to_user((void __user *) data.target,
                    target, data.data_size)) {
            kfree(target);
            return -EFAULT;
        }
    }

    kfree(target);

    if (__copy_to_user((void __user *) arg, &data, sizeof(data))) {
        return -EFAULT;
    }

    return 0;
}

/*****************************************************************************/

/** Download SDO.
 */
int ec_cdev_ioctl_slave_sdo_download(
        ec_master_t *master, /**< EtherCAT master. */
        unsigned long arg /**< ioctl() argument. */
        )
{
    ec_ioctl_slave_sdo_download_t data;
    uint8_t *sdo_data;
    int retval;

    if (copy_from_user(&data, (void __user *) arg, sizeof(data))) {
        return -EFAULT;
    }

    if (!(sdo_data = kmalloc(data.data_size, GFP_KERNEL))) {
        EC_MASTER_ERR(master, "Failed to allocate %u bytes"
                " for SDO download.\n", data.data_size);
        return -ENOMEM;
    }

    if (copy_from_user(sdo_data, (void __user *) data.data, data.data_size)) {
        kfree(sdo_data);
        return -EFAULT;
    }

    if (data.complete_access) {
        retval = ecrt_master_sdo_download_complete(master, data.slave_position,
                data.sdo_index, sdo_data, data.data_size, &data.abort_code);
    } else {
        retval = ecrt_master_sdo_download(master, data.slave_position,
                data.sdo_index, data.sdo_entry_subindex, sdo_data,
                data.data_size, &data.abort_code);
    }

    kfree(sdo_data);

    if (__copy_to_user((void __user *) arg, &data, sizeof(data))) {
        retval = -EFAULT;
    }

    return retval;
}

/*****************************************************************************/

/** Read a slave's SII.
 */
int ec_cdev_ioctl_slave_sii_read(
        ec_master_t *master, /**< EtherCAT master. */
        unsigned long arg /**< ioctl() argument. */
        )
{
    ec_ioctl_slave_sii_t data;
    const ec_slave_t *slave;
    int retval;

    if (copy_from_user(&data, (void __user *) arg, sizeof(data))) {
        return -EFAULT;
    }

    if (down_interruptible(&master->master_sem))
        return -EINTR;

    if (!(slave = ec_master_find_slave_const(
                    master, 0, data.slave_position))) {
        up(&master->master_sem);
        EC_MASTER_ERR(master, "Slave %u does not exist!\n",
                data.slave_position);
        return -EINVAL;
    }

    if (!data.nwords
            || data.offset + data.nwords > slave->sii_nwords) {
        up(&master->master_sem);
        EC_SLAVE_ERR(slave, "Invalid SII read offset/size %u/%u for slave SII"
                " size %zu!\n", data.offset, data.nwords, slave->sii_nwords);
        return -EINVAL;
    }

    if (copy_to_user((void __user *) data.words,
                slave->sii_words + data.offset, data.nwords * 2))
        retval = -EFAULT;
    else
        retval = 0;

    up(&master->master_sem);
    return retval;
}

/*****************************************************************************/

/** Write a slave's SII.
 */
int ec_cdev_ioctl_slave_sii_write(
        ec_master_t *master, /**< EtherCAT master. */
        unsigned long arg /**< ioctl() argument. */
        )
{
    ec_ioctl_slave_sii_t data;
    ec_slave_t *slave;
    unsigned int byte_size;
    uint16_t *words;
    ec_sii_write_request_t request;

    if (copy_from_user(&data, (void __user *) arg, sizeof(data))) {
        return -EFAULT;
    }

    if (!data.nwords)
        return 0;

    byte_size = sizeof(uint16_t) * data.nwords;
    if (!(words = kmalloc(byte_size, GFP_KERNEL))) {
        EC_MASTER_ERR(master, "Failed to allocate %u bytes"
                " for SII contents.\n", byte_size);
        return -ENOMEM;
    }