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

     2

 *

     3

 *  $Id$

     4

 *

     5

 *  Copyright (C) 2006-2008  Florian Pose, Ingenieurgemeinschaft IgH

     6

 *

     7

 *  This file is part of the IgH EtherCAT Master.

     8

 *

     9

 *  The IgH EtherCAT Master is free software; you can redistribute it and/or

    10

 *  modify it under the terms of the GNU General Public License version 2, as

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 *  published by the Free Software Foundation.

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 *

    13

 *  The IgH EtherCAT Master is distributed in the hope that it will be useful,

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 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

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 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General

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 *  Public License for more details.

    17

 *

    18

 *  You should have received a copy of the GNU General Public License along

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 *  with the IgH EtherCAT Master; if not, write to the Free Software

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 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

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 *

    22

 *  ---

    23

 *

    24

 *  The license mentioned above concerns the source code only. Using the

    25

 *  EtherCAT technology and brand is only permitted in compliance with the

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 *  industrial property and similar rights of Beckhoff Automation GmbH.

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 *

    28

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

    29

    30

/** \file

    31

 * EtherCAT tty driver module.

    32

 */

    33

    34

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

    35

    36

#include <linux/module.h>

    37

#include <linux/err.h>

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#include <linux/tty.h>

    39

#include <linux/tty_driver.h>

    40

#include <linux/tty_flip.h>

    41

#include <linux/termios.h>

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#include <linux/timer.h>

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#include <linux/version.h>

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#include <linux/serial.h>

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#include <linux/uaccess.h>

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#include <linux/slab.h>

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#include "../master/globals.h"

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#include "../include/ectty.h"

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

    52

    53

#define PFX "ec_tty: "

    54

    55

#define EC_TTY_MAX_DEVICES 32

    56

#define EC_TTY_TX_BUFFER_SIZE 100

    57

#define EC_TTY_RX_BUFFER_SIZE 100

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    59

#define EC_TTY_DEBUG 0

    60

    61

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

    62

    63

char *ec_master_version_str = EC_MASTER_VERSION; /**< Version string. */

    64

unsigned int debug_level = 0;

    65

    66

static struct tty_driver *tty_driver = NULL;

    67

ec_tty_t *ttys[EC_TTY_MAX_DEVICES];

    68

struct semaphore tty_sem;

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    70

void ec_tty_wakeup(unsigned long);

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    72

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

    73

    74

/** \cond */

    75

    76

MODULE_AUTHOR("Florian Pose <fp@igh-essen.com>");

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MODULE_DESCRIPTION("EtherCAT TTY driver module");

    78

MODULE_LICENSE("GPL");

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MODULE_VERSION(EC_MASTER_VERSION);

    80

    81

module_param_named(debug_level, debug_level, uint, S_IRUGO);

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MODULE_PARM_DESC(debug_level, "Debug level");

    83

    84

/** \endcond */

    85

    86

/** Standard termios for ec_tty devices.

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 *

    88

 * Simplest possible configuration, as you would expect.

    89

 */

    90

static struct ktermios ec_tty_std_termios = {

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    .c_iflag = 0,

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    .c_oflag = 0,

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    .c_cflag = B9600 | CS8 | CREAD,

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    .c_lflag = 0,

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    .c_cc = INIT_C_CC,

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};

    97

    98

struct ec_tty {

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    int minor;

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    struct device *dev;

   101

   102

    uint8_t tx_buffer[EC_TTY_TX_BUFFER_SIZE];

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    unsigned int tx_read_idx;

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    unsigned int tx_write_idx;

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    unsigned int wakeup;

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   107

    uint8_t rx_buffer[EC_TTY_RX_BUFFER_SIZE];

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    unsigned int rx_read_idx;

   109

    unsigned int rx_write_idx;

   110

   111

    struct timer_list timer;

   112

    struct tty_struct *tty;

   113

    unsigned int open_count;

   114

    struct semaphore sem;

   115

   116

    ec_tty_operations_t ops;

   117

    void *cb_data;

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};

   119

   120

static const struct tty_operations ec_tty_ops; // see below

   121

   122

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

   123

   124

/** Module initialization.

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 *

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 * \return 0 on success, else < 0

   127

 */

   128

int __init ec_tty_init_module(void)

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{

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    int i, ret = 0;

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   132

    printk(KERN_INFO PFX "TTY driver %s\n", EC_MASTER_VERSION);

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   134

    sema_init(&tty_sem, 1);

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   136

    for (i = 0; i < EC_TTY_MAX_DEVICES; i++) {

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        ttys[i] = NULL;

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    }

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   140

    tty_driver = alloc_tty_driver(EC_TTY_MAX_DEVICES);

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    if (!tty_driver) {

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        printk(KERN_ERR PFX "Failed to allocate tty driver.\n");

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        ret = -ENOMEM;

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        goto out_return;

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    }

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    tty_driver->owner = THIS_MODULE;

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    tty_driver->driver_name = "EtherCAT TTY";

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    tty_driver->name = "ttyEC";

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    tty_driver->major = 0;

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    tty_driver->minor_start = 0;

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    tty_driver->type = TTY_DRIVER_TYPE_SERIAL;

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    tty_driver->subtype = SERIAL_TYPE_NORMAL;

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    tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;

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    tty_driver->init_termios = ec_tty_std_termios;

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    tty_set_operations(tty_driver, &ec_tty_ops);

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   158

    ret = tty_register_driver(tty_driver);

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    if (ret) {

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        printk(KERN_ERR PFX "Failed to register tty driver.\n");

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        goto out_put;

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    }

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    return ret;

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out_put:

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    put_tty_driver(tty_driver);

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out_return:

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    return ret;

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}

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   172

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

   173

   174

/** Module cleanup.

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 *

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 * Clears all master instances.

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 */

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void __exit ec_tty_cleanup_module(void)

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{

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    tty_unregister_driver(tty_driver);

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    put_tty_driver(tty_driver);

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    printk(KERN_INFO PFX "Module unloading.\n");

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}

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   185

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

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 * ec_tty_t methods.

   187

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

   188

   189

int ec_tty_init(ec_tty_t *t, int minor,

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        const ec_tty_operations_t *ops, void *cb_data)

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{

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    int ret;

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    tcflag_t cflag;

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    struct tty_struct *tty;

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    struct ktermios *termios;

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   197

    t->minor = minor;

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    t->tx_read_idx = 0;

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    t->tx_write_idx = 0;

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    t->wakeup = 0;

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    t->rx_read_idx = 0;

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    t->rx_write_idx = 0;

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    init_timer(&t->timer);

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    t->tty = NULL;

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    t->open_count = 0;

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    sema_init(&t->sem, 1);

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    t->ops = *ops;

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    t->cb_data = cb_data;

   209

   210

    t->dev = tty_register_device(tty_driver, t->minor, NULL);

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    if (IS_ERR(t->dev)) {

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        printk(KERN_ERR PFX "Failed to register tty device.\n");

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        return PTR_ERR(t->dev);

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    }

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    // Tell the device-specific implementation about the initial cflags

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    tty = tty_driver->ttys[minor];

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    termios =

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#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 7, 0)

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        &tty->termios

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#else

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        tty->termios

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#endif

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        ;

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    if (tty && termios) { // already opened before

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        cflag = termios->c_cflag;

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    } else {

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        cflag = tty_driver->init_termios.c_cflag;

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    }

   232

    ret = t->ops.cflag_changed(t->cb_data, cflag);

   233

    if (ret) {

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        printk(KERN_ERR PFX "ERROR: Initial cflag 0x%x not accepted.\n",

   235

                cflag);

   236

        tty_unregister_device(tty_driver, t->minor);

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        return ret;

   238

    }

   239

   240

    t->timer.function = ec_tty_wakeup;

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    t->timer.data = (unsigned long) t;

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    t->timer.expires = jiffies + 10;

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    add_timer(&t->timer);

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    return 0;

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}

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   247

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

   248

   249

void ec_tty_clear(ec_tty_t *tty)

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{

   251

    del_timer_sync(&tty->timer);

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    tty_unregister_device(tty_driver, tty->minor);

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}

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   255

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

   256

   257

unsigned int ec_tty_tx_size(ec_tty_t *tty)

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{

   259

    unsigned int ret;

   260

   261

    if (tty->tx_write_idx >= tty->tx_read_idx) {

   262

        ret = tty->tx_write_idx - tty->tx_read_idx;

   263

    } else {

   264

        ret = EC_TTY_TX_BUFFER_SIZE + tty->tx_write_idx - tty->tx_read_idx;

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    }

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    return ret;

   268

}

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   270

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

   271

   272

unsigned int ec_tty_tx_space(ec_tty_t *tty)

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{

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    return EC_TTY_TX_BUFFER_SIZE - 1 - ec_tty_tx_size(tty);

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}

   276

   277

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

   278

   279

unsigned int ec_tty_rx_size(ec_tty_t *tty)

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{

   281

    unsigned int ret;

   282

   283

    if (tty->rx_write_idx >= tty->rx_read_idx) {

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        ret = tty->rx_write_idx - tty->rx_read_idx;

   285

    } else {

   286

        ret = EC_TTY_RX_BUFFER_SIZE + tty->rx_write_idx - tty->rx_read_idx;

   287

    }

   288

   289

    return ret;

   290

}

   291

   292

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

   293

   294

unsigned int ec_tty_rx_space(ec_tty_t *tty)

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{

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    return EC_TTY_RX_BUFFER_SIZE - 1 - ec_tty_rx_size(tty);

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}

   298

   299

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

   300

   301

int ec_tty_get_serial_info(ec_tty_t *tty, struct serial_struct *data)

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{

   303

    struct serial_struct tmp;

   304

   305

    if (!data)

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        return -EFAULT;

   307

   308

    memset(&tmp, 0, sizeof(tmp));

   309

   310

    if (copy_to_user(data, &tmp, sizeof(*data))) {

   311

        return -EFAULT;

   312

    }

   313

    return 0;

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}

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   316

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

   317

   318

/** Timer function.

   319

 */

   320

void ec_tty_wakeup(unsigned long data)

   321

{

   322

    ec_tty_t *tty = (ec_tty_t *) data;

   323

    size_t to_recv;

   324

   325

    /* Wake up any process waiting to send data */

   326

    if (tty->wakeup) {

   327

        if (tty->tty) {

   328

#if EC_TTY_DEBUG >= 1

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            printk(KERN_INFO PFX "Waking up.\n");

   330

#endif

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            tty_wakeup(tty->tty);

   332

        }

   333

        tty->wakeup = 0;

   334

    }

   335

   336

    /* Push received data into TTY core. */

   337

    to_recv = ec_tty_rx_size(tty);

   338

    if (to_recv && tty->tty) {

   339

        unsigned char *cbuf;

   340

        int space = tty_prepare_flip_string(tty->tty, &cbuf, to_recv);

   341

   342

        if (space < to_recv) {

   343

            printk(KERN_WARNING PFX "Insufficient space to_recv=%d space=%d\n",

   344

                    to_recv, space);

   345

        }

   346

   347

        if (space < 0) {

   348

            to_recv = 0;

   349

        } else {

   350

            to_recv = space;

   351

        }

   352

   353

        if (to_recv) {

   354

            unsigned int i;

   355

   356

#if EC_TTY_DEBUG >= 1

   357

            printk(KERN_INFO PFX "Pushing %u bytes to TTY core.\n", to_recv);

   358

#endif

   359

   360

            for (i = 0; i < to_recv; i++) {

   361

                cbuf[i] = tty->rx_buffer[tty->rx_read_idx];

   362

                tty->rx_read_idx =

   363

                    (tty->rx_read_idx + 1) % EC_TTY_RX_BUFFER_SIZE;

   364

            }

   365

            tty_flip_buffer_push(tty->tty);

   366

        }

   367

    }

   368

   369

    tty->timer.expires += 1;

   370

    add_timer(&tty->timer);

   371

}

   372

   373

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

   374

 * Device callbacks

   375

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

   376

   377

static int ec_tty_open(struct tty_struct *tty, struct file *file)

   378

{

   379

    ec_tty_t *t;

   380

    int line = tty->index;

   381

   382

#if EC_TTY_DEBUG >= 1

   383

    printk(KERN_INFO PFX "%s(tty=%p, file=%p): Opening line %i.\n",

   384

            __func__, tty, file, line);

   385

#endif

   386

   387

    if (line < 0 || line >= EC_TTY_MAX_DEVICES) {

   388

        tty->driver_data = NULL;

   389

        return -ENXIO;

   390

    }

   391

   392

    t = ttys[line];

   393

    if (!t) {

   394

        tty->driver_data = NULL;

   395

        return -ENXIO;

   396

    }

   397

   398

    if (!t->tty) {

   399

        t->tty = tty;

   400

        tty->driver_data = t;

   401

    }

   402

   403

    down(&t->sem);

   404

    t->open_count++;

   405

    up(&t->sem);

   406

    return 0;

   407

}

   408

   409

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

   410

   411

static void ec_tty_close(struct tty_struct *tty, struct file *file)

   412

{

   413

    ec_tty_t *t = (ec_tty_t *) tty->driver_data;

   414

   415

#if EC_TTY_DEBUG >= 1

   416

    printk(KERN_INFO PFX "%s(tty=%p, file=%p): Closing line %i.\n",

   417

            __func__, tty, file, tty->index);

   418

#endif

   419

   420

    if (t) {

   421

        down(&t->sem);

   422

        if (--t->open_count == 0) {

   423

            t->tty = NULL;

   424

        }

   425

        up(&t->sem);

   426

    }

   427

}

   428

   429

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

   430

   431

static int ec_tty_write(

   432

        struct tty_struct *tty,

   433

        const unsigned char *buffer,

   434

        int count

   435

        )

   436

{

   437

    ec_tty_t *t = (ec_tty_t *) tty->driver_data;

   438

    unsigned int data_size, i;

   439

   440

#if EC_TTY_DEBUG >= 1

   441

    printk(KERN_INFO PFX "%s(count=%i)\n", __func__, count);

   442

#endif

   443

   444

    if (count <= 0) {

   445

        return 0;

   446

    }

   447

   448

    data_size = min(ec_tty_tx_space(t), (unsigned int) count);

   449

    for (i = 0; i < data_size; i++) {

   450

        t->tx_buffer[t->tx_write_idx] = buffer[i];

   451

        t->tx_write_idx = (t->tx_write_idx + 1) % EC_TTY_TX_BUFFER_SIZE;

   452

    }

   453

   454

#if EC_TTY_DEBUG >= 1

   455

    printk(KERN_INFO PFX "%s(): %u bytes written.\n", __func__, data_size);

   456

#endif

   457

    return data_size;

   458

}

   459

   460

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

   461

   462

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 26)

   463

static int ec_tty_put_char(struct tty_struct *tty, unsigned char ch)

   464

#else

   465

static void ec_tty_put_char(struct tty_struct *tty, unsigned char ch)

   466

#endif

   467

{

   468

    ec_tty_t *t = (ec_tty_t *) tty->driver_data;

   469

   470

#if EC_TTY_DEBUG >= 1

   471

    printk(KERN_INFO PFX "%s(): c=%02x.\n", __func__, (unsigned int) ch);

   472

#endif

   473

   474

    if (ec_tty_tx_space(t)) {

   475

        t->tx_buffer[t->tx_write_idx] = ch;

   476

        t->tx_write_idx = (t->tx_write_idx + 1) % EC_TTY_TX_BUFFER_SIZE;

   477

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 26)

   478

        return 1;

   479

#endif

   480

    } else {

   481

        printk(KERN_WARNING PFX "%s(): Dropped a byte!\n", __func__);

   482

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 26)

   483

        return 0;

   484

#endif

   485

    }

   486

}

   487

   488

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

   489

   490

static int ec_tty_write_room(struct tty_struct *tty)

   491

{

   492

    ec_tty_t *t = (ec_tty_t *) tty->driver_data;