fsm_coe.c

/******************************************************************************
 *
 *  $Id$
 *
 *  Copyright (C) 2006  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
 *  as published by the Free Software Foundation; either version 2 of the
 *  License, or (at your option) any later version.
 *
 *  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 right to use EtherCAT Technology is granted and comes free of
 *  charge under condition of compatibility of product made by
 *  Licensee. People intending to distribute/sell products based on the
 *  code, have to sign an agreement to guarantee that products using
 *  software based on IgH EtherCAT master stay compatible with the actual
 *  EtherCAT specification (which are released themselves as an open
 *  standard) as the (only) precondition to have the right to use EtherCAT
 *  Technology, IP and trade marks.
 *
 *****************************************************************************/

/**
   \file
   EtherCAT CoE state machines.
*/

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

#include "globals.h"
#include "master.h"
#include "mailbox.h"
#include "fsm_coe.h"

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

void ec_fsm_coe_dict_start(ec_fsm_coe_t *);
void ec_fsm_coe_dict_request(ec_fsm_coe_t *);
void ec_fsm_coe_dict_check(ec_fsm_coe_t *);
void ec_fsm_coe_dict_response(ec_fsm_coe_t *);
void ec_fsm_coe_dict_desc_request(ec_fsm_coe_t *);
void ec_fsm_coe_dict_desc_check(ec_fsm_coe_t *);
void ec_fsm_coe_dict_desc_response(ec_fsm_coe_t *);
void ec_fsm_coe_dict_entry_request(ec_fsm_coe_t *);
void ec_fsm_coe_dict_entry_check(ec_fsm_coe_t *);
void ec_fsm_coe_dict_entry_response(ec_fsm_coe_t *);

void ec_fsm_coe_down_start(ec_fsm_coe_t *);
void ec_fsm_coe_down_request(ec_fsm_coe_t *);
void ec_fsm_coe_down_check(ec_fsm_coe_t *);
void ec_fsm_coe_down_response(ec_fsm_coe_t *);

void ec_fsm_coe_up_start(ec_fsm_coe_t *);
void ec_fsm_coe_up_request(ec_fsm_coe_t *);
void ec_fsm_coe_up_check(ec_fsm_coe_t *);
void ec_fsm_coe_up_response(ec_fsm_coe_t *);
void ec_fsm_coe_up_seg_request(ec_fsm_coe_t *);
void ec_fsm_coe_up_seg_check(ec_fsm_coe_t *);
void ec_fsm_coe_up_seg_response(ec_fsm_coe_t *);

void ec_fsm_coe_end(ec_fsm_coe_t *);
void ec_fsm_coe_error(ec_fsm_coe_t *);

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

/**
   SDO abort messages.
   The "abort SDO transfer request" supplies an abort code,
   which can be translated to clear text. This table does
   the mapping of the codes and messages.
*/

const ec_code_msg_t sdo_abort_messages[] = {
    {0x05030000, "Toggle bit not changed"},
    {0x05040000, "SDO protocol timeout"},
    {0x05040001, "Client/Server command specifier not valid or unknown"},
    {0x05040005, "Out of memory"},
    {0x06010000, "Unsupported access to an object"},
    {0x06010001, "Attempt to read a write-only object"},
    {0x06010002, "Attempt to write a read-only object"},
    {0x06020000, "This object does not exist in the object directory"},
    {0x06040041, "The object cannot be mapped into the PDO"},
    {0x06040042, "The number and length of the objects to be mapped would"
     " exceed the PDO length"},
    {0x06040043, "General parameter incompatibility reason"},
    {0x06040047, "Gerneral internal incompatibility in device"},
    {0x06060000, "Access failure due to a hardware error"},
    {0x06070010, "Data type does not match, length of service parameter does"
     " not match"},
    {0x06070012, "Data type does not match, length of service parameter too"
     " high"},
    {0x06070013, "Data type does not match, length of service parameter too"
     " low"},
    {0x06090011, "Subindex does not exist"},
    {0x06090030, "Value range of parameter exceeded"},
    {0x06090031, "Value of parameter written too high"},
    {0x06090032, "Value of parameter written too low"},
    {0x06090036, "Maximum value is less than minimum value"},
    {0x08000000, "General error"},
    {0x08000020, "Data cannot be transferred or stored to the application"},
    {0x08000021, "Data cannot be transferred or stored to the application"
     " because of local control"},
    {0x08000022, "Data cannot be transferred or stored to the application"
     " because of the present device state"},
    {0x08000023, "Object dictionary dynamic generation fails or no object"
     " dictionary is present"},
    {}
};

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

/**
   Outputs an SDO abort message.
*/

void ec_canopen_abort_msg(uint32_t abort_code)
{
    const ec_code_msg_t *abort_msg;

    for (abort_msg = sdo_abort_messages; abort_msg->code; abort_msg++) {
        if (abort_msg->code == abort_code) {
            EC_ERR("SDO abort message 0x%08X: \"%s\".\n",
                   abort_msg->code, abort_msg->message);
            return;
        }
    }

    EC_ERR("Unknown SDO abort code 0x%08X.\n", abort_code);
}

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

/**
   Constructor.
*/

void ec_fsm_coe_init(ec_fsm_coe_t *fsm, /**< finite state machine */
                     ec_datagram_t *datagram /**< datagram */
                     )
{
    fsm->state = NULL;
    fsm->datagram = datagram;
}

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

/**
   Destructor.
*/

void ec_fsm_coe_clear(ec_fsm_coe_t *fsm /**< finite state machine */)
{
}

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

/**
   Starts reading a slaves' SDO dictionary.
*/

void ec_fsm_coe_dictionary(ec_fsm_coe_t *fsm, /**< finite state machine */
                           ec_slave_t *slave /**< EtherCAT slave */
                           )
{
    fsm->slave = slave;
    fsm->state = ec_fsm_coe_dict_start;
}

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

/**
   Starts to download an SDO to a slave.
*/

void ec_fsm_coe_download(ec_fsm_coe_t *fsm, /**< finite state machine */
                         ec_slave_t *slave, /**< EtherCAT slave */
                         ec_sdo_data_t *sdodata /**< SDO data object */
                         )
{
    fsm->slave = slave;
    fsm->sdodata = sdodata;
    fsm->state = ec_fsm_coe_down_start;
}

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

/**
   Starts to upload an SDO from a slave.
*/

void ec_fsm_coe_upload(ec_fsm_coe_t *fsm, /**< finite state machine */
                       ec_slave_t *slave, /**< EtherCAT slave */
                       ec_sdo_request_t *request /**< SDO request */
                       )
{
    fsm->slave = slave;
    fsm->request = request;
    fsm->state = ec_fsm_coe_up_start;
}

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

/**
   Executes the current state of the state machine.
   \return false, if state machine has terminated
*/

int ec_fsm_coe_exec(ec_fsm_coe_t *fsm /**< finite state machine */)
{
    fsm->state(fsm);

    return fsm->state != ec_fsm_coe_end && fsm->state != ec_fsm_coe_error;
}

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

/**
   Returns, if the state machine terminated with success.
   \return non-zero if successful.
*/

int ec_fsm_coe_success(ec_fsm_coe_t *fsm /**< Finite state machine */)
{
    return fsm->state == ec_fsm_coe_end;
}

/******************************************************************************
 *  CoE dictionary state machine
 *****************************************************************************/

/**
   CoE state: DICT START.
*/

void ec_fsm_coe_dict_start(ec_fsm_coe_t *fsm /**< finite state machine */)
{
    ec_datagram_t *datagram = fsm->datagram;
    ec_slave_t *slave = fsm->slave;
    uint8_t *data;

    if (!(data = ec_slave_mbox_prepare_send(slave, datagram, 0x03, 8))) {
        fsm->state = ec_fsm_coe_error;
        return;
    }

    EC_WRITE_U16(data, 0x8 << 12); // SDO information
    EC_WRITE_U8 (data + 2, 0x01); // Get OD List Request
    EC_WRITE_U8 (data + 3, 0x00);
    EC_WRITE_U16(data + 4, 0x0000);
    EC_WRITE_U16(data + 6, 0x0001); // deliver all SDOs!

    ec_master_queue_datagram(fsm->slave->master, datagram);
    fsm->state = ec_fsm_coe_dict_request;
}

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

/**
   CoE state: DICT REQUEST.
*/

void ec_fsm_coe_dict_request(ec_fsm_coe_t *fsm /**< finite state machine */)
{
    ec_datagram_t *datagram = fsm->datagram;
    ec_slave_t *slave = fsm->slave;

    if (datagram->state != EC_DATAGRAM_RECEIVED
        || datagram->working_counter != 1) {
        fsm->state = ec_fsm_coe_error;
        EC_ERR("Reception of CoE dictionary request failed on slave %i.\n",
               slave->ring_position);
        return;
    }

    fsm->cycles_start = datagram->cycles_sent;

    ec_slave_mbox_prepare_check(slave, datagram); // can not fail.
    ec_master_queue_datagram(fsm->slave->master, datagram);
    fsm->state = ec_fsm_coe_dict_check;
}

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

/**
   CoE state: DICT CHECK.
*/

void ec_fsm_coe_dict_check(ec_fsm_coe_t *fsm /**< finite state machine */)
{
    ec_datagram_t *datagram = fsm->datagram;
    ec_slave_t *slave = fsm->slave;

    if (datagram->state != EC_DATAGRAM_RECEIVED
        || datagram->working_counter != 1) {
        fsm->state = ec_fsm_coe_error;
        EC_ERR("Reception of CoE mailbox check datagram failed on slave %i.\n",
               slave->ring_position);
        return;
    }

    if (!ec_slave_mbox_check(datagram)) {
        if (datagram->cycles_received
            - fsm->cycles_start >= (cycles_t) 100 * cpu_khz) {
            fsm->state = ec_fsm_coe_error;
            EC_ERR("Timeout while checking SDO dictionary on slave %i.\n",
                   slave->ring_position);
            return;
        }

        ec_slave_mbox_prepare_check(slave, datagram); // can not fail.
        ec_master_queue_datagram(fsm->slave->master, datagram);
        return;
    }

    // Fetch response
    ec_slave_mbox_prepare_fetch(slave, datagram); // can not fail.
    ec_master_queue_datagram(fsm->slave->master, datagram);
    fsm->state = ec_fsm_coe_dict_response;
}

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

/**
   CoE state: DICT RESPONSE.
*/

void ec_fsm_coe_dict_response(ec_fsm_coe_t *fsm /**< finite state machine */)
{
    ec_datagram_t *datagram = fsm->datagram;
    ec_slave_t *slave = fsm->slave;
    uint8_t *data, mbox_prot;
    size_t rec_size;
    unsigned int sdo_count, i;
    uint16_t sdo_index;
    ec_sdo_t *sdo;

    if (datagram->state != EC_DATAGRAM_RECEIVED
        || datagram->working_counter != 1) {
        fsm->state = ec_fsm_coe_error;
        EC_ERR("Reception of CoE dictionary response failed on slave %i.\n",
               slave->ring_position);
        return;
    }

    if (!(data = ec_slave_mbox_fetch(slave, datagram,
				     &mbox_prot, &rec_size))) {
        fsm->state = ec_fsm_coe_error;
        return;
    }

    if (mbox_prot != 0x03) { // CoE
        EC_ERR("Received mailbox protocol 0x%02X as response.\n", mbox_prot);
        fsm->state = ec_fsm_coe_error;
	return;
    }

    if (EC_READ_U16(data) >> 12 == 0x8 && // SDO information
        (EC_READ_U8(data + 2) & 0x7F) == 0x07) { // error response
        EC_ERR("SDO information error response at slave %i!\n",
               slave->ring_position);
        ec_canopen_abort_msg(EC_READ_U32(data + 6));
        fsm->state = ec_fsm_coe_error;
	return;
    }

    if (EC_READ_U16(data) >> 12 != 0x8 || // SDO information
        (EC_READ_U8 (data + 2) & 0x7F) != 0x02) { // Get OD List response
        EC_ERR("Invalid SDO list response at slave %i!\n",
               slave->ring_position);
        ec_print_data(data, rec_size);
        fsm->state = ec_fsm_coe_error;
	return;
    }

    if (rec_size < 8) {
        EC_ERR("Invalid data size!\n");
        ec_print_data(data, rec_size);
        fsm->state = ec_fsm_coe_error;
	return;
    }

    sdo_count = (rec_size - 8) / 2;

    for (i = 0; i < sdo_count; i++) {
        sdo_index = EC_READ_U16(data + 8 + i * 2);
        if (!sdo_index) {
            EC_WARN("SDO dictionary of slave %i contains index 0x0000.\n",
                    slave->ring_position);
            continue;
        }

        if (!(sdo = (ec_sdo_t *) kmalloc(sizeof(ec_sdo_t), GFP_ATOMIC))) {
            EC_ERR("Failed to allocate memory for SDO!\n");
            fsm->state = ec_fsm_coe_error;
            return;
        }

        if (ec_sdo_init(sdo, sdo_index, slave)) {
            EC_ERR("Failed to init SDO!\n");
            fsm->state = ec_fsm_coe_error;
            return;
        }

        if (kobject_add(&sdo->kobj)) {
            EC_ERR("Failed to add kobject.\n");
            kobject_put(&sdo->kobj); // free
            fsm->state = ec_fsm_coe_error;
            return;
        }

        list_add_tail(&sdo->list, &slave->sdo_dictionary);
    }

    if (EC_READ_U8(data + 2) & 0x80) { // more messages waiting. check again.
        fsm->cycles_start = datagram->cycles_sent;
        ec_slave_mbox_prepare_check(slave, datagram); // can not fail.
        ec_master_queue_datagram(fsm->slave->master, datagram);
        fsm->state = ec_fsm_coe_dict_check;
        return;
    }

    if (list_empty(&slave->sdo_dictionary)) {
        // no SDOs in dictionary. finished.
        fsm->state = ec_fsm_coe_end; // success
        return;
    }

    // fetch SDO descriptions
    fsm->sdo = list_entry(slave->sdo_dictionary.next, ec_sdo_t, list);

    if (!(data = ec_slave_mbox_prepare_send(slave, datagram, 0x03, 8))) {
        fsm->state = ec_fsm_coe_error;
        return;
    }

    EC_WRITE_U16(data, 0x8 << 12); // SDO information
    EC_WRITE_U8 (data + 2, 0x03); // Get object description request
    EC_WRITE_U8 (data + 3, 0x00);
    EC_WRITE_U16(data + 4, 0x0000);
    EC_WRITE_U16(data + 6, fsm->sdo->index); // SDO index

    ec_master_queue_datagram(fsm->slave->master, datagram);
    fsm->state = ec_fsm_coe_dict_desc_request;
}

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

/**
   CoE state: DICT DESC REQUEST.
*/

void ec_fsm_coe_dict_desc_request(ec_fsm_coe_t *fsm /**< finite state machine */)
{
    ec_datagram_t *datagram = fsm->datagram;
    ec_slave_t *slave = fsm->slave;

    if (datagram->state != EC_DATAGRAM_RECEIVED
        || datagram->working_counter != 1) {
        fsm->state = ec_fsm_coe_error;
        EC_ERR("Reception of CoE SDO description"
               " request failed on slave %i.\n", slave->ring_position);
        return;
    }

    fsm->cycles_start = datagram->cycles_sent;

    ec_slave_mbox_prepare_check(slave, datagram); // can not fail.
    ec_master_queue_datagram(fsm->slave->master, datagram);
    fsm->state = ec_fsm_coe_dict_desc_check;
}

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

/**
   CoE state: DICT DESC CHECK.
*/

void ec_fsm_coe_dict_desc_check(ec_fsm_coe_t *fsm /**< finite state machine */)
{
    ec_datagram_t *datagram = fsm->datagram;
    ec_slave_t *slave = fsm->slave;

    if (datagram->state != EC_DATAGRAM_RECEIVED
        || datagram->working_counter != 1) {
        fsm->state = ec_fsm_coe_error;
        EC_ERR("Reception of CoE mailbox check datagram failed on slave %i.\n",
               slave->ring_position);
        return;
    }

    if (!ec_slave_mbox_check(datagram)) {
        if (datagram->cycles_received
            - fsm->cycles_start >= (cycles_t) 100 * cpu_khz) {
            fsm->state = ec_fsm_coe_error;
            EC_ERR("Timeout while checking SDO description on slave %i.\n",
                   slave->ring_position);
            return;
        }

        ec_slave_mbox_prepare_check(slave, datagram); // can not fail.
        ec_master_queue_datagram(fsm->slave->master, datagram);
        return;
    }

    // Fetch response
    ec_slave_mbox_prepare_fetch(slave, datagram); // can not fail.
    ec_master_queue_datagram(fsm->slave->master, datagram);
    fsm->state = ec_fsm_coe_dict_desc_response;
}

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

/**
   CoE state: DICT DESC RESPONSE.
*/

void ec_fsm_coe_dict_desc_response(ec_fsm_coe_t *fsm
                                   /**< finite state machine */)
{
    ec_datagram_t *datagram = fsm->datagram;
    ec_slave_t *slave = fsm->slave;
    ec_sdo_t *sdo = fsm->sdo;
    uint8_t *data, mbox_prot;
    size_t rec_size, name_size;

    if (datagram->state != EC_DATAGRAM_RECEIVED
        || datagram->working_counter != 1) {
        fsm->state = ec_fsm_coe_error;
        EC_ERR("Reception of CoE SDO description"
               "response failed on slave %i.\n", slave->ring_position);
        return;
    }

    if (!(data = ec_slave_mbox_fetch(slave, datagram,
				     &mbox_prot, &rec_size))) {
        fsm->state = ec_fsm_coe_error;
        return;
    }

    if (mbox_prot != 0x03) { // CoE
        EC_ERR("Received mailbox protocol 0x%02X as response.\n", mbox_prot);
        fsm->state = ec_fsm_coe_error;
	return;
    }

    if (EC_READ_U16(data) >> 12 == 0x8 && // SDO information
        (EC_READ_U8 (data + 2) & 0x7F) == 0x07) { // error response
        EC_ERR("SDO information error response at slave %i while"
               " fetching SDO 0x%04X!\n", slave->ring_position,
               sdo->index);
        ec_canopen_abort_msg(EC_READ_U32(data + 6));
        fsm->state = ec_fsm_coe_error;
	return;
    }

    if (EC_READ_U16(data) >> 12 != 0x8 || // SDO information
        (EC_READ_U8 (data + 2) & 0x7F) != 0x04 || // Object desc. response
        EC_READ_U16(data + 6) != sdo->index) { // SDO index
        EC_ERR("Invalid object description response at slave %i while"
               " fetching SDO 0x%04X!\n", slave->ring_position,
               sdo->index);
        ec_print_data(data, rec_size);
        fsm->state = ec_fsm_coe_error;
	return;
    }

    if (rec_size < 12) {
        EC_ERR("Invalid data size!\n");
        ec_print_data(data, rec_size);
        fsm->state = ec_fsm_coe_error;
	return;
    }

    sdo->subindices = EC_READ_U8(data + 10);
    sdo->object_code = EC_READ_U8(data + 11);

    name_size = rec_size - 12;
    if (name_size) {
        if (!(sdo->name = kmalloc(name_size + 1, GFP_ATOMIC))) {
            EC_ERR("Failed to allocate SDO name!\n");
            fsm->state = ec_fsm_coe_error;
            return;
        }

        memcpy(sdo->name, data + 12, name_size);
        sdo->name[name_size] = 0;
    }

    if (EC_READ_U8(data + 2) & 0x80) {
        EC_ERR("Fragment follows (not implemented)!\n");
        fsm->state = ec_fsm_coe_error;
	return;
    }

    // start fetching entries

    fsm->subindex = 0;

    if (!(data = ec_slave_mbox_prepare_send(slave, datagram, 0x03, 10))) {
        fsm->state = ec_fsm_coe_error;
        return;
    }

    EC_WRITE_U16(data, 0x8 << 12); // SDO information
    EC_WRITE_U8 (data + 2, 0x05); // Get entry description request
    EC_WRITE_U8 (data + 3, 0x00);
    EC_WRITE_U16(data + 4, 0x0000);
    EC_WRITE_U16(data + 6, sdo->index); // SDO index
    EC_WRITE_U8 (data + 8, fsm->subindex); // SDO subindex
    EC_WRITE_U8 (data + 9, 0x00); // value info (no values)

    ec_master_queue_datagram(fsm->slave->master, datagram);
    fsm->state = ec_fsm_coe_dict_entry_request;
}

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

/**
   CoE state: DICT ENTRY REQUEST.
*/

void ec_fsm_coe_dict_entry_request(ec_fsm_coe_t *fsm
                                   /**< finite state machine */)
{
    ec_datagram_t *datagram = fsm->datagram;
    ec_slave_t *slave = fsm->slave;

    if (datagram->state != EC_DATAGRAM_RECEIVED
        || datagram->working_counter != 1) {
        fsm->state = ec_fsm_coe_error;
        EC_ERR("Reception of CoE SDO entry request failed on slave %i.\n",
               slave->ring_position);
        return;
    }

    fsm->cycles_start = datagram->cycles_sent;

    ec_slave_mbox_prepare_check(slave, datagram); // can not fail.
    ec_master_queue_datagram(fsm->slave->master, datagram);
    fsm->state = ec_fsm_coe_dict_entry_check;
}

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

/**
   CoE state: DICT ENTRY CHECK.
*/

void ec_fsm_coe_dict_entry_check(ec_fsm_coe_t *fsm
                                 /**< finite state machine */)
{
    ec_datagram_t *datagram = fsm->datagram;
    ec_slave_t *slave = fsm->slave;

    if (datagram->state != EC_DATAGRAM_RECEIVED
        || datagram->working_counter != 1) {
        fsm->state = ec_fsm_coe_error;
        EC_ERR("Reception of CoE mailbox check datagram failed on slave %i.\n",
               slave->ring_position);
        return;
    }

    if (!ec_slave_mbox_check(datagram)) {
        if (datagram->cycles_received
            - fsm->cycles_start >= (cycles_t) 100 * cpu_khz) {
            fsm->state = ec_fsm_coe_error;
            EC_ERR("Timeout while checking SDO entry on slave %i.\n",
                   slave->ring_position);
            return;
        }

        ec_slave_mbox_prepare_check(slave, datagram); // can not fail.
        ec_master_queue_datagram(fsm->slave->master, datagram);
        return;
    }

    // Fetch response
    ec_slave_mbox_prepare_fetch(slave, datagram); // can not fail.
    ec_master_queue_datagram(fsm->slave->master, datagram);
    fsm->state = ec_fsm_coe_dict_entry_response;
}

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

/**
   CoE state: DICT ENTRY RESPONSE.
*/

void ec_fsm_coe_dict_entry_response(ec_fsm_coe_t *fsm
                                    /**< finite state machine */)
{
    ec_datagram_t *datagram = fsm->datagram;
    ec_slave_t *slave = fsm->slave;
    ec_sdo_t *sdo = fsm->sdo;
    uint8_t *data, mbox_prot;
    size_t rec_size, data_size;
    ec_sdo_entry_t *entry;

    if (datagram->state != EC_DATAGRAM_RECEIVED
        || datagram->working_counter != 1) {
        fsm->state = ec_fsm_coe_error;
        EC_ERR("Reception of CoE SDO description"
               " response failed on slave %i.\n", slave->ring_position);
        return;
    }

    if (!(data = ec_slave_mbox_fetch(slave, datagram,
				     &mbox_prot, &rec_size))) {
        fsm->state = ec_fsm_coe_error;
        return;
    }

    if (mbox_prot != 0x03) { // CoE
        EC_ERR("Received mailbox protocol 0x%02X as response.\n", mbox_prot);
        fsm->state = ec_fsm_coe_error;
	return;
    }

    if (EC_READ_U16(data) >> 12 == 0x8 && // SDO information
        (EC_READ_U8 (data + 2) & 0x7F) == 0x07) { // error response
        EC_ERR("SDO information error response at slave %i while"
               " fetching SDO entry 0x%04X:%i!\n", slave->ring_position,
               sdo->index, fsm->subindex);
        ec_canopen_abort_msg(EC_READ_U32(data + 6));
        fsm->state = ec_fsm_coe_error;
	return;
    }

    if (EC_READ_U16(data) >> 12 != 0x8 || // SDO information
        (EC_READ_U8(data + 2) & 0x7F) != 0x06 || // Entry desc. response
        EC_READ_U16(data + 6) != sdo->index || // SDO index
        EC_READ_U8(data + 8) != fsm->subindex) { // SDO subindex
        EC_ERR("Invalid entry description response at slave %i while"
               " fetching SDO entry 0x%04X:%i!\n", slave->ring_position,
               sdo->index, fsm->subindex);
        ec_print_data(data, rec_size);
        fsm->state = ec_fsm_coe_error;
	return;
    }

    if (rec_size < 16) {
        EC_ERR("Invalid data size!\n");
        ec_print_data(data, rec_size);
        fsm->state = ec_fsm_coe_error;
	return;
    }

    data_size = rec_size - 16;

    if (!(entry = (ec_sdo_entry_t *)
          kmalloc(sizeof(ec_sdo_entry_t), GFP_ATOMIC))) {
        EC_ERR("Failed to allocate entry!\n");
        fsm->state = ec_fsm_coe_error;
	return;
    }

    if (ec_sdo_entry_init(entry, fsm->subindex, sdo)) {
        EC_ERR("Failed to init entry!\n");
        fsm->state = ec_fsm_coe_error;
	return;
    }

    entry->data_type = EC_READ_U16(data + 10);
    entry->bit_length = EC_READ_U16(data + 12);

    if (data_size) {
        if (!(entry->description = kmalloc(data_size + 1, GFP_ATOMIC))) {
            EC_ERR("Failed to allocate SDO entry name!\n");
            fsm->state = ec_fsm_coe_error;
            return;
        }
        memcpy(entry->description, data + 16, data_size);
        entry->description[data_size] = 0;
    }

    if (kobject_add(&entry->kobj)) {
        EC_ERR("Failed to add kobject.\n");
        kobject_put(&entry->kobj); // free
        fsm->state = ec_fsm_coe_error;
        return;
    }

    list_add_tail(&entry->list, &sdo->entries);

    if (fsm->subindex < sdo->subindices) {
        fsm->subindex++;

        if (!(data = ec_slave_mbox_prepare_send(slave, datagram, 0x03, 10))) {
            fsm->state = ec_fsm_coe_error;
            return;
        }

        EC_WRITE_U16(data, 0x8 << 12); // SDO information
        EC_WRITE_U8 (data + 2, 0x05); // Get entry description request
        EC_WRITE_U8 (data + 3, 0x00);
        EC_WRITE_U16(data + 4, 0x0000);
        EC_WRITE_U16(data + 6, sdo->index); // SDO index
        EC_WRITE_U8 (data + 8, fsm->subindex); // SDO subindex
        EC_WRITE_U8 (data + 9, 0x00); // value info (no values)

        ec_master_queue_datagram(fsm->slave->master, datagram);
        fsm->state = ec_fsm_coe_dict_entry_request;
        return;
    }

    // another SDO description to fetch?
    if (fsm->sdo->list.next != &slave->sdo_dictionary) {
        fsm->sdo = list_entry(fsm->sdo->list.next, ec_sdo_t, list);

        if (!(data = ec_slave_mbox_prepare_send(slave, datagram, 0x03, 8))) {
            fsm->state = ec_fsm_coe_error;
            return;
        }

        EC_WRITE_U16(data, 0x8 << 12); // SDO information
        EC_WRITE_U8 (data + 2, 0x03); // Get object description request
        EC_WRITE_U8 (data + 3, 0x00);
        EC_WRITE_U16(data + 4, 0x0000);
        EC_WRITE_U16(data + 6, fsm->sdo->index); // SDO index

        ec_master_queue_datagram(fsm->slave->master, datagram);
        fsm->state = ec_fsm_coe_dict_desc_request;
        return;
    }

    fsm->state = ec_fsm_coe_end;
}

/******************************************************************************
 *  CoE state machine
 *****************************************************************************/

/**
   CoE state: DOWN START.
*/

void ec_fsm_coe_down_start(ec_fsm_coe_t *fsm /**< finite state machine */)
{
    ec_datagram_t *datagram = fsm->datagram;
    ec_slave_t *slave = fsm->slave;
    ec_sdo_data_t *sdodata = fsm->sdodata;
    uint8_t *data;

    if (fsm->slave->master->debug_level)
        EC_DBG("Downloading SDO 0x%04X:%i to slave %i.\n",
               sdodata->index, sdodata->subindex, slave->ring_position);

    if (slave->sii_rx_mailbox_size < 6 + 10 + sdodata->size) {
        EC_ERR("SDO fragmenting not supported yet!\n");
        fsm->state = ec_fsm_coe_error;
        return;
    }

    if (!(data = ec_slave_mbox_prepare_send(slave, datagram, 0x03,
                                            sdodata->size + 10))) {
        fsm->state = ec_fsm_coe_error;
        return;
    }

    EC_WRITE_U16(data, 0x2 << 12); // SDO request
    EC_WRITE_U8 (data + 2, (0x1 // size specified
                            | 0x1 << 5)); // Download request
    EC_WRITE_U16(data + 3, sdodata->index);
    EC_WRITE_U8 (data + 5, sdodata->subindex);
    EC_WRITE_U32(data + 6, sdodata->size);
    memcpy(data + 10, sdodata->data, sdodata->size);

    ec_master_queue_datagram(fsm->slave->master, datagram);
    fsm->state = ec_fsm_coe_down_request;
}

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

/**
   CoE state: DOWN REQUEST.
*/

void ec_fsm_coe_down_request(ec_fsm_coe_t *fsm /**< finite state machine */)
{
    ec_datagram_t *datagram = fsm->datagram;
    ec_slave_t *slave = fsm->slave;

    if (datagram->state != EC_DATAGRAM_RECEIVED
        || datagram->working_counter != 1) {
        fsm->state = ec_fsm_coe_error;
        EC_ERR("Reception of CoE download request failed.\n");
        return;
    }

    fsm->cycles_start = datagram->cycles_sent;

    ec_slave_mbox_prepare_check(slave, datagram); // can not fail.
    ec_master_queue_datagram(fsm->slave->master, datagram);
    fsm->state = ec_fsm_coe_down_check;
}

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

/**
   CoE state: DOWN CHECK.
*/

void ec_fsm_coe_down_check(ec_fsm_coe_t *fsm /**< finite state machine */)
{
    ec_datagram_t *datagram = fsm->datagram;
    ec_slave_t *slave = fsm->slave;

    if (datagram->state != EC_DATAGRAM_RECEIVED
        || datagram->working_counter != 1) {
        fsm->state = ec_fsm_coe_error;
        EC_ERR("Reception of CoE mailbox check datagram failed.\n");
        return;
    }

    if (!ec_slave_mbox_check(datagram)) {
        if (datagram->cycles_received
            - fsm->cycles_start >= (cycles_t) 100 * cpu_khz) {
            fsm->state = ec_fsm_coe_error;
            EC_ERR("Timeout while checking SDO configuration on slave %i.\n",
                   slave->ring_position);
            return;
        }

        ec_slave_mbox_prepare_check(slave, datagram); // can not fail.
        ec_master_queue_datagram(fsm->slave->master, datagram);
        return;
    }

    // Fetch response
    ec_slave_mbox_prepare_fetch(slave, datagram); // can not fail.
    ec_master_queue_datagram(fsm->slave->master, datagram);
    fsm->state = ec_fsm_coe_down_response;
}

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

/**
   CoE state: DOWN RESPONSE.
*/

void ec_fsm_coe_down_response(ec_fsm_coe_t *fsm /**< finite state machine */)
{
    ec_datagram_t *datagram = fsm->datagram;
    ec_slave_t *slave = fsm->slave;
    uint8_t *data, mbox_prot;
    size_t rec_size;
    ec_sdo_data_t *sdodata = fsm->sdodata;

    if (datagram->state != EC_DATAGRAM_RECEIVED
        || datagram->working_counter != 1) {
        fsm->state = ec_fsm_coe_error;
        EC_ERR("Reception of CoE download response failed.\n");
        return;
    }

    if (!(data = ec_slave_mbox_fetch(slave, datagram,
				     &mbox_prot, &rec_size))) {
        fsm->state = ec_fsm_coe_error;
        return;
    }

    if (mbox_prot != 0x03) { // CoE
        EC_ERR("Received mailbox protocol 0x%02X as response.\n", mbox_prot);
        fsm->state = ec_fsm_coe_error;
	return;
    }

    if (rec_size < 6) {
        fsm->state = ec_fsm_coe_error;
        EC_ERR("Received data is too small (%i bytes):\n", rec_size);
        ec_print_data(data, rec_size);
        return;
    }

    if (EC_READ_U16(data) >> 12 == 0x2 && // SDO request
        EC_READ_U8 (data + 2) >> 5 == 0x4) { // abort SDO transfer request
        fsm->state = ec_fsm_coe_error;
        EC_ERR("SDO download 0x%04X:%X (%i bytes) aborted on slave %i.\n",
               sdodata->index, sdodata->subindex, sdodata->size,
               slave->ring_position);
        if (rec_size < 10) {
            EC_ERR("Incomplete Abort command:\n");
            ec_print_data(data, rec_size);
        }
        else
            ec_canopen_abort_msg(EC_READ_U32(data + 6));
        return;
    }