module.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 master driver module.
*/

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

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>

#include "globals.h"
#include "master.h"
#include "device.h"

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

int __init ec_init_module(void);
void __exit ec_cleanup_module(void);

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

static int ec_master_count = 1; /**< parameter value, number of masters */
static int ec_eoeif_count = 0; /**< parameter value, number of EoE interf. */
static struct list_head ec_masters; /**< list of masters */
static dev_t device_number;

char *ec_master_version_str = EC_MASTER_VERSION;

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

/** \cond */

module_param(ec_master_count, int, S_IRUGO);
module_param(ec_eoeif_count, int, S_IRUGO);

MODULE_AUTHOR("Florian Pose <fp@igh-essen.com>");
MODULE_DESCRIPTION("EtherCAT master driver module");
MODULE_LICENSE("GPL");
MODULE_VERSION(EC_MASTER_VERSION);
MODULE_PARM_DESC(ec_master_count, "number of EtherCAT masters to initialize");
MODULE_PARM_DESC(ec_eoeif_count, "number of EoE interfaces per master");

/** \endcond */

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

/**
   Module initialization.
   Initializes \a ec_master_count masters.
   \return 0 on success, else < 0
*/

int __init ec_init_module(void)
{
    unsigned int i;
    ec_master_t *master, *next;

    EC_INFO("Master driver %s\n", EC_MASTER_VERSION);

    if (ec_master_count < 1) {
        EC_ERR("Invalid ec_master_count: %i\n", ec_master_count);
        goto out_return;
    }

    if (alloc_chrdev_region(&device_number, 0, ec_master_count, "EtherCAT")) {
        EC_ERR("Failed to allocate device number!\n");
        goto out_return;
    }

    EC_INFO("Initializing %i EtherCAT master(s)...\n", ec_master_count);

    INIT_LIST_HEAD(&ec_masters);

    for (i = 0; i < ec_master_count; i++) {
        if (!(master =
              (ec_master_t *) kmalloc(sizeof(ec_master_t), GFP_KERNEL))) {
            EC_ERR("Failed to allocate memory for EtherCAT master %i.\n", i);
            goto out_free;
        }

        if (ec_master_init(master, i, ec_eoeif_count, device_number))
            goto out_free;

        list_add_tail(&master->list, &ec_masters);
    }

    EC_INFO("Master driver initialized.\n");
    return 0;

 out_free:
    list_for_each_entry_safe(master, next, &ec_masters, list) {
        list_del(&master->list);
        kobject_del(&master->kobj);
        kobject_put(&master->kobj);
    }
 out_return:
    return -1;
}

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

/**
   Module cleanup.
   Clears all master instances.
*/

void __exit ec_cleanup_module(void)
{
    ec_master_t *master, *next;

    EC_INFO("Cleaning up master driver...\n");

    list_for_each_entry_safe(master, next, &ec_masters, list) {
        list_del(&master->list);
        ec_master_destroy(master);
    }

    unregister_chrdev_region(device_number, ec_master_count);

    EC_INFO("Master driver cleaned up.\n");
}

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

/**
   Gets a handle to a certain master.
   \returns pointer to master
*/

ec_master_t *ec_find_master(unsigned int master_index /**< master index */)
{
    ec_master_t *master;

    list_for_each_entry(master, &ec_masters, list) {
        if (master->index == master_index) return master;
    }

    EC_ERR("Master %i does not exist!\n", master_index);
    return NULL;
}

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

/**
   Outputs frame contents for debugging purposes.
*/

void ec_print_data(const uint8_t *data, /**< pointer to data */
                   size_t size /**< number of bytes to output */
                   )
{
    unsigned int i;

    EC_DBG("");
    for (i = 0; i < size; i++) {
        printk("%02X ", data[i]);
        if ((i + 1) % 16 == 0) {
            printk("\n");
            EC_DBG("");
        }
    }
    printk("\n");
}

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

/**
   Outputs frame contents and differences for debugging purposes.
*/

void ec_print_data_diff(const uint8_t *d1, /**< first data */
                        const uint8_t *d2, /**< second data */
                        size_t size /** number of bytes to output */
                        )
{
    unsigned int i;

    EC_DBG("");
    for (i = 0; i < size; i++) {
        if (d1[i] == d2[i]) printk(".. ");
        else printk("%02X ", d2[i]);
        if ((i + 1) % 16 == 0) {
            printk("\n");
            EC_DBG("");
        }
    }
    printk("\n");
}

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

/**
   Prints slave states in clear text.
*/

size_t ec_state_string(uint8_t states, /**< slave states */
                       char *buffer /**< target buffer
                                       (min. EC_STATE_STRING_SIZE bytes) */
                       )
{
    off_t off = 0;
    unsigned int first = 1;

    if (!states) {
        off += sprintf(buffer + off, "(unknown)");
        return off;
    }

    if (states & EC_SLAVE_STATE_INIT) {
        off += sprintf(buffer + off, "INIT");
        first = 0;
    }
    if (states & EC_SLAVE_STATE_PREOP) {
        if (!first) off += sprintf(buffer + off, ", ");
        off += sprintf(buffer + off, "PREOP");
        first = 0;
    }
    if (states & EC_SLAVE_STATE_SAVEOP) {
        if (!first) off += sprintf(buffer + off, ", ");
        off += sprintf(buffer + off, "SAVEOP");
        first = 0;
    }
    if (states & EC_SLAVE_STATE_OP) {
        if (!first) off += sprintf(buffer + off, ", ");
        off += sprintf(buffer + off, "OP");
    }
    if (states & EC_SLAVE_STATE_ACK_ERR) {
        if (!first) off += sprintf(buffer + off, " + ");
        off += sprintf(buffer + off, "ERROR");
    }

    return off;
}

/******************************************************************************
 *  Device interface
 *****************************************************************************/

/**
   Connects an EtherCAT device to a certain master.
   The master will use the device for sending and receiving frames. It is
   required that no other instance (for example the kernel IP stack) uses
   the device.
   \return 0 on success, else < 0
   \ingroup DeviceInterface
*/

ec_device_t *ecdev_register(unsigned int master_index, /**< master index */
                            struct net_device *net_dev, /**< net_device of
                                                           the device */
                            ec_pollfunc_t poll, /**< device poll function */
                            struct module *module /**< pointer to the module */
                            )
{
    ec_master_t *master;

    if (!(master = ec_find_master(master_index))) return NULL;

    if (down_interruptible(&master->device_sem)) {
        EC_ERR("Interrupted while waiting for device!\n");
        goto out_return;
    }

    if (master->device) {
        EC_ERR("Master %i already has a device!\n", master_index);
        goto out_up;
    }

    if (!(master->device =
          (ec_device_t *) kmalloc(sizeof(ec_device_t), GFP_KERNEL))) {
        EC_ERR("Failed to allocate device!\n");
        goto out_up;
    }

    if (ec_device_init(master->device, master, net_dev, poll, module)) {
        EC_ERR("Failed to init device!\n");
        goto out_free;
    }

    up(&master->device_sem);
    return master->device;

 out_free:
    kfree(master->device);
    master->device = NULL;
 out_up:
    up(&master->device_sem);
 out_return:
    return NULL;
}

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

/**
   Disconnect an EtherCAT device from the master.
   The device is disconnected from the master and all device ressources
   are freed.
   \attention Before calling this function, the ecdev_stop() function has
   to be called, to be sure that the master does not use the device any more.
   \ingroup DeviceInterface
*/

void ecdev_unregister(unsigned int master_index, /**< master index */
                      ec_device_t *device /**< EtherCAT device */
                      )
{
    ec_master_t *master;

    if (!(master = ec_find_master(master_index))) return;

    down(&master->device_sem);

    if (!master->device || master->device != device) {
        up(&master->device_sem);
        EC_WARN("Unable to unregister device!\n");
        return;
    }

    ec_device_clear(master->device);
    kfree(master->device);
    master->device = NULL;

    up(&master->device_sem);
}

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

/**
   Opens the network device and makes the master enter IDLE mode.
   \return 0 on success, else < 0
   \ingroup DeviceInterface
*/

int ecdev_open(ec_device_t *device /**< EtherCAT device */)
{
    if (ec_device_open(device)) {
        EC_ERR("Failed to open device!\n");
        return -1;
    }

    if (ec_master_enter_idle_mode(device->master)) {
        EC_ERR("Failed to enter idle mode!\n");
        return -1;
    }

    return 0;
}

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

/**
   Makes the master leave IDLE mode and closes the network device.
   \return 0 on success, else < 0
   \ingroup DeviceInterface
*/

void ecdev_close(ec_device_t *device /**< EtherCAT device */)
{
    ec_master_leave_idle_mode(device->master);

    if (ec_device_close(device))
        EC_WARN("Failed to close device!\n");
}

/******************************************************************************
 *  Realtime interface
 *****************************************************************************/

/**
   Reserves an EtherCAT master for realtime operation.
   \return pointer to reserved master, or NULL on error
   \ingroup RealtimeInterface
*/

ec_master_t *ecrt_request_master(unsigned int master_index
                                 /**< master index */
                                 )
{
    ec_master_t *master;

    EC_INFO("Requesting master %i...\n", master_index);

    if (!(master = ec_find_master(master_index))) goto out_return;

    if (!atomic_dec_and_test(&master->available)) {
        atomic_inc(&master->available);
        EC_ERR("Master %i is already in use!\n", master_index);
        goto out_return;
    }

    if (down_interruptible(&master->device_sem)) {
        EC_ERR("Interrupted while waiting for device!\n");
        goto out_release;
    }

    if (!master->device) {
        up(&master->device_sem);
        EC_ERR("Master %i has no assigned device!\n", master_index);
        goto out_release;
    }

    if (!try_module_get(master->device->module)) {
        up(&master->device_sem);
        EC_ERR("Device module is unloading!\n");
        goto out_release;
    }

    up(&master->device_sem);

    if (!master->device->link_state) {
        EC_ERR("Link is DOWN.\n");
        goto out_module_put;
    }

    if (ec_master_enter_operation_mode(master)) {
        EC_ERR("Failed to enter OPERATION mode!\n");
        goto out_module_put;
    }

    EC_INFO("Successfully requested master %i.\n", master_index);
    return master;

 out_module_put:
    module_put(master->device->module);
 out_release:
    atomic_inc(&master->available);
 out_return:
    return NULL;
}

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

/**
   Releases a reserved EtherCAT master.
   \ingroup RealtimeInterface
*/

void ecrt_release_master(ec_master_t *master /**< EtherCAT master */)
{
    EC_INFO("Releasing master %i...\n", master->index);

    if (master->mode != EC_MASTER_MODE_OPERATION) {
        EC_WARN("Master %i was was not requested!\n", master->index);
        return;
    }

    ec_master_leave_operation_mode(master);

    module_put(master->device->module);
    atomic_inc(&master->available);

    EC_INFO("Released master %i.\n", master->index);
}

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

/** \cond */

module_init(ec_init_module);
module_exit(ec_cleanup_module);

EXPORT_SYMBOL(ecdev_register);
EXPORT_SYMBOL(ecdev_unregister);
EXPORT_SYMBOL(ecdev_open);
EXPORT_SYMBOL(ecdev_close);
EXPORT_SYMBOL(ecrt_request_master);
EXPORT_SYMBOL(ecrt_release_master);

/** \endcond */

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