/******************************************************************************
 *
 *  m o d u l e . c
 *
 *  EtherCAT-Master-Treiber
 *
 *  Autoren: Wilhelm Hagemeister, Florian Pose
 *
 *  $Id$
 *
 *  (C) Copyright IgH 2005
 *  Ingenieurgemeinschaft IgH
 *  Heinz-Bäcker Str. 34
 *  D-45356 Essen
 *  Tel.: +49 201/61 99 31
 *  Fax.: +49 201/61 98 36
 *  E-mail: sp@igh-essen.com
 *
 *****************************************************************************/

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

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

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

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

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

#define EC_LIT(X) #X
#define EC_STR(X) EC_LIT(X)

#define COMPILE_INFO "Revision " EC_STR(SVNREV) \
                     ", compiled by " EC_STR(USER) \
                     " at " __DATE__ " " __TIME__

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

int ec_master_count = 1;
ec_master_t *ec_masters = NULL;
unsigned int *ec_masters_reserved = NULL;

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

MODULE_AUTHOR ("Florian Pose <fp@igh-essen.com>");
MODULE_DESCRIPTION ("EtherCAT master driver module");
MODULE_LICENSE("GPL");
MODULE_VERSION(COMPILE_INFO);

module_param(ec_master_count, int, 1);
MODULE_PARM_DESC(ec_master_count, "Number of EtherCAT master to initialize.");

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

/**
   Init-Funktion des EtherCAT-Master-Treibermodules

   Initialisiert soviele Master, wie im Parameter ec_master_count
   angegeben wurde (Default ist 1).

   \return 0 wenn alles ok, < 0 bei ungültiger Anzahl Master
           oder zu wenig Speicher.
*/

int __init ec_init_module(void)
{
    unsigned int i;

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

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

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

    if (!(ec_masters = (ec_master_t *)
          kmalloc(sizeof(ec_master_t) * ec_master_count, GFP_KERNEL))) {
        EC_ERR("Failed to allocate master(s)!\n");
        goto out_return;
    }

    if (!(ec_masters_reserved = (unsigned int *)
          kmalloc(sizeof(int) * ec_master_count, GFP_KERNEL))) {
        EC_ERR("Failed to allocate reservation flags!\n");
        goto out_free_masters;
    }

    for (i = 0; i < ec_master_count; i++) {
        ec_master_init(ec_masters + i);
        ec_masters_reserved[i] = 0;
    }

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

 out_free_masters:
    kfree(ec_masters);
 out_return:
    return -1;
}

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

/**
   Cleanup-Funktion des EtherCAT-Master-Treibermoduls

   Entfernt alle Master-Instanzen.
*/

void __exit ec_cleanup_module(void)
{
    unsigned int i;

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

    for (i = 0; i < ec_master_count; i++) {
        if (ec_masters_reserved[i])
            EC_WARN("Master %i is still in use!\n", i);
        ec_master_clear(&ec_masters[i]);
    }

    kfree(ec_masters);
    kfree(ec_masters_reserved);

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

/******************************************************************************
 *
 * Treiberschnittstelle
 *
 *****************************************************************************/

/**
   Registeriert das EtherCAT-Geraet fuer einen EtherCAT-Master.

   \return 0 wenn alles ok, oder < 0 wenn bereits ein Gerät registriert
           oder das Geraet nicht geöffnet werden konnte.
*/

ec_device_t *ecdev_register(unsigned int master_index,
                            /**< Index des EtherCAT-Masters */
                            struct net_device *net_dev,
                            /**< net_device des EtherCAT-Gerätes */
                            ec_isr_t isr,
                            /**< Interrupt-Service-Routine */
                            struct module *module
                            /**< Zeiger auf das Modul */
                            )
{
    ec_master_t *master;

    if (!net_dev) {
        EC_WARN("Device is NULL!\n");
        return NULL;
    }

    if (master_index >= ec_master_count) {
        EC_ERR("Master %i does not exist!\n", master_index);
        return NULL;
    }

    master = ec_masters + master_index;

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

    if (!(master->device = (ec_device_t *)
          kmalloc(sizeof(ec_device_t), GFP_KERNEL))) {
        EC_ERR("Failed allocating device!\n");
        return NULL;
    }

    if (ec_device_init(master->device, master, net_dev, isr, module)) {
        kfree(master->device);
        master->device = NULL;
        return NULL;
    }

    return master->device;
}

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

/**
   Hebt die Registrierung eines EtherCAT-Gerätes auf.
*/

void ecdev_unregister(unsigned int master_index,
                      /**< Index des EtherCAT-Masters */
                      ec_device_t *device
                      /**< EtherCAT-Geraet */
                      )
{
    ec_master_t *master;

    if (master_index >= ec_master_count) {
        EC_WARN("Master %i does not exist!\n", master_index);
        return;
    }

    master = ec_masters + master_index;

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

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

/******************************************************************************
 *
 * Echtzeitschnittstelle
 *
 *****************************************************************************/

/**
   Reserviert einen bestimmten EtherCAT-Master und das zugehörige Gerät.

   Gibt einen Zeiger auf den reservierten EtherCAT-Master zurueck.

   \return Zeiger auf EtherCAT-Master oder NULL, wenn Parameter ungueltig.
*/

ec_master_t *ecrt_request_master(unsigned int index
                                 /**< EtherCAT-Master-Index */
                                 )
{
    ec_master_t *master;

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

    if (index < 0 || index >= ec_master_count) {
        EC_ERR("Master %i does not exist!\n", index);
        goto req_return;
    }

    if (ec_masters_reserved[index]) {
        EC_ERR("Master %i is already in use!\n", index);
        goto req_return;
    }

    ec_masters_reserved[index] = 1;
    master = &ec_masters[index];

    if (!master->device) {
        EC_ERR("Master %i has no assigned device!\n", index);
        goto req_release;
    }

    if (!try_module_get(master->device->module)) {
        EC_ERR("Failed to reserve device module!\n");
        goto req_release;
    }

    if (ec_device_open(master->device)) {
        EC_ERR("Failed to open device!\n");
        goto req_module_put;
    }

    if (!master->device->link_state)
        EC_WARN("Link is DOWN.\n");

    if (ec_master_bus_scan(master) != 0) {
        EC_ERR("Bus scan failed!\n");
        goto req_close;
    }

    EC_INFO("Master %i is ready.\n", index);
    return master;

 req_close:
    if (ec_device_close(master->device))
        EC_WARN("Warning - Failed to close device!\n");
 req_module_put:
    module_put(master->device->module);
    ec_master_reset(master);
 req_release:
    ec_masters_reserved[index] = 0;
 req_return:
    EC_ERR("Failed requesting master %i.\n", index);
    return NULL;
}

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

/**
   Gibt einen zuvor angeforderten EtherCAT-Master wieder frei.
*/

void ecrt_release_master(ec_master_t *master /**< EtherCAT-Master */)
{
    unsigned int i, found;

    found = 0;
    for (i = 0; i < ec_master_count; i++) {
        if (&ec_masters[i] == master) {
            found = 1;
            break;
        }
    }

    if (!found) {
        EC_WARN("Master 0x%08X was never requested!\n", (u32) master);
        return;
    }

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

    ec_master_reset(master);

    if (ec_device_close(master->device))
        EC_WARN("Warning - Failed to close device!\n");

    module_put(master->device->module);
    ec_masters_reserved[i] = 0;

    EC_INFO("Released master %i.\n", i);
    return;
}

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

module_init(ec_init_module);
module_exit(ec_cleanup_module);

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

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

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