/******************************************************************************
*
* $Id$
*
* 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 tty driver module.
*/
/*****************************************************************************/
#include <linux/module.h>
#include <linux/err.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/termios.h>
#include <linux/timer.h>
#include <linux/version.h>
#include <linux/serial.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include "../master/globals.h"
#include "../include/ectty.h"
/*****************************************************************************/
#define PFX "ec_tty: "
#define EC_TTY_MAX_DEVICES 32
#define EC_TTY_TX_BUFFER_SIZE 100
#define EC_TTY_RX_BUFFER_SIZE 100
#define EC_TTY_DEBUG 0
/*****************************************************************************/
char *ec_master_version_str = EC_MASTER_VERSION; /**< Version string. */
unsigned int debug_level = 0;
static struct tty_driver *tty_driver = NULL;
ec_tty_t *ttys[EC_TTY_MAX_DEVICES];
struct semaphore tty_sem;
void ec_tty_wakeup(unsigned long);
/*****************************************************************************/
/** \cond */
MODULE_AUTHOR("Florian Pose <fp@igh-essen.com>");
MODULE_DESCRIPTION("EtherCAT TTY driver module");
MODULE_LICENSE("GPL");
MODULE_VERSION(EC_MASTER_VERSION);
module_param_named(debug_level, debug_level, uint, S_IRUGO);
MODULE_PARM_DESC(debug_level, "Debug level");
/** \endcond */
/** Standard termios for ec_tty devices.
*
* Simplest possible configuration, as you would expect.
*/
static struct ktermios ec_tty_std_termios = {
.c_iflag = 0,
.c_oflag = 0,
.c_cflag = B9600 | CS8 | CREAD,
.c_lflag = 0,
.c_cc = INIT_C_CC,
};
struct ec_tty {
int minor;
struct device *dev;
uint8_t tx_buffer[EC_TTY_TX_BUFFER_SIZE];
unsigned int tx_read_idx;
unsigned int tx_write_idx;
unsigned int wakeup;
uint8_t rx_buffer[EC_TTY_RX_BUFFER_SIZE];
unsigned int rx_read_idx;
unsigned int rx_write_idx;
struct timer_list timer;
struct tty_struct *tty;
unsigned int open_count;
struct semaphore sem;
ec_tty_operations_t ops;
void *cb_data;
};
static const struct tty_operations ec_tty_ops; // see below
/*****************************************************************************/
/** Module initialization.
*
* \return 0 on success, else < 0
*/
int __init ec_tty_init_module(void)
{
int i, ret = 0;
printk(KERN_INFO PFX "TTY driver %s\n", EC_MASTER_VERSION);
sema_init(&tty_sem, 1);
for (i = 0; i < EC_TTY_MAX_DEVICES; i++) {
ttys[i] = NULL;
}
tty_driver = alloc_tty_driver(EC_TTY_MAX_DEVICES);
if (!tty_driver) {
printk(KERN_ERR PFX "Failed to allocate tty driver.\n");
ret = -ENOMEM;
goto out_return;
}
tty_driver->owner = THIS_MODULE;
tty_driver->driver_name = "EtherCAT TTY";
tty_driver->name = "ttyEC";
tty_driver->major = 0;
tty_driver->minor_start = 0;
tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
tty_driver->subtype = SERIAL_TYPE_NORMAL;
tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
tty_driver->init_termios = ec_tty_std_termios;
tty_set_operations(tty_driver, &ec_tty_ops);
ret = tty_register_driver(tty_driver);
if (ret) {
printk(KERN_ERR PFX "Failed to register tty driver.\n");
goto out_put;
}
return ret;
out_put:
put_tty_driver(tty_driver);
out_return:
return ret;
}
/*****************************************************************************/
/** Module cleanup.
*
* Clears all master instances.
*/
void __exit ec_tty_cleanup_module(void)
{
tty_unregister_driver(tty_driver);
put_tty_driver(tty_driver);
printk(KERN_INFO PFX "Module unloading.\n");
}
/******************************************************************************
* ec_tty_t methods.
*****************************************************************************/
int ec_tty_init(ec_tty_t *t, int minor,
const ec_tty_operations_t *ops, void *cb_data)
{
int ret;
tcflag_t cflag;
struct tty_struct *tty;
t->minor = minor;
t->tx_read_idx = 0;
t->tx_write_idx = 0;
t->wakeup = 0;
t->rx_read_idx = 0;
t->rx_write_idx = 0;
init_timer(&t->timer);
t->tty = NULL;
t->open_count = 0;
sema_init(&t->sem, 1);
t->ops = *ops;
t->cb_data = cb_data;
t->dev = tty_register_device(tty_driver, t->minor, NULL);
if (IS_ERR(t->dev)) {
printk(KERN_ERR PFX "Failed to register tty device.\n");
return PTR_ERR(t->dev);
}
// Tell the device-specific implementation about the initial cflags
tty = tty_driver->ttys[minor];
if (tty && tty->termios) { // already opened before
cflag = tty->termios->c_cflag;
} else {
cflag = tty_driver->init_termios.c_cflag;
}
ret = t->ops.cflag_changed(t->cb_data, cflag);
if (ret) {
printk(KERN_ERR PFX "ERROR: Initial cflag 0x%x not accepted.\n",
cflag);
tty_unregister_device(tty_driver, t->minor);
return ret;
}
t->timer.function = ec_tty_wakeup;
t->timer.data = (unsigned long) t;
t->timer.expires = jiffies + 10;
add_timer(&t->timer);
return 0;
}
/*****************************************************************************/
void ec_tty_clear(ec_tty_t *tty)
{
del_timer_sync(&tty->timer);
tty_unregister_device(tty_driver, tty->minor);
}
/*****************************************************************************/
unsigned int ec_tty_tx_size(ec_tty_t *tty)
{
unsigned int ret;
if (tty->tx_write_idx >= tty->tx_read_idx) {
ret = tty->tx_write_idx - tty->tx_read_idx;
} else {
ret = EC_TTY_TX_BUFFER_SIZE + tty->tx_write_idx - tty->tx_read_idx;
}
return ret;
}
/*****************************************************************************/
unsigned int ec_tty_tx_space(ec_tty_t *tty)
{
return EC_TTY_TX_BUFFER_SIZE - 1 - ec_tty_tx_size(tty);
}
/*****************************************************************************/
unsigned int ec_tty_rx_size(ec_tty_t *tty)
{
unsigned int ret;
if (tty->rx_write_idx >= tty->rx_read_idx) {
ret = tty->rx_write_idx - tty->rx_read_idx;
} else {
ret = EC_TTY_RX_BUFFER_SIZE + tty->rx_write_idx - tty->rx_read_idx;
}
return ret;
}
/*****************************************************************************/
unsigned int ec_tty_rx_space(ec_tty_t *tty)
{
return EC_TTY_RX_BUFFER_SIZE - 1 - ec_tty_rx_size(tty);
}
/*****************************************************************************/
int ec_tty_get_serial_info(ec_tty_t *tty, struct serial_struct *data)
{
struct serial_struct tmp;
if (!data)
return -EFAULT;
memset(&tmp, 0, sizeof(tmp));
if (copy_to_user(data, &tmp, sizeof(*data))) {
return -EFAULT;
}
return 0;
}
/*****************************************************************************/
/** Timer function.
*/
void ec_tty_wakeup(unsigned long data)
{
ec_tty_t *tty = (ec_tty_t *) data;
size_t to_recv;
/* Wake up any process waiting to send data */
if (tty->wakeup) {
if (tty->tty) {
#if EC_TTY_DEBUG >= 1
printk(KERN_INFO PFX "Waking up.\n");
#endif
tty_wakeup(tty->tty);
}
tty->wakeup = 0;
}
/* Push received data into TTY core. */
to_recv = ec_tty_rx_size(tty);
if (to_recv && tty->tty) {
unsigned char *cbuf;
int space = tty_prepare_flip_string(tty->tty, &cbuf, to_recv);
if (space < to_recv) {
printk(KERN_WARNING PFX "Insufficient space to_recv=%d space=%d\n",
to_recv, space);
}
if (space < 0) {
to_recv = 0;
} else {
to_recv = space;
}
if (to_recv) {
unsigned int i;
#if EC_TTY_DEBUG >= 1
printk(KERN_INFO PFX "Pushing %u bytes to TTY core.\n", to_recv);
#endif
for (i = 0; i < to_recv; i++) {
cbuf[i] = tty->rx_buffer[tty->rx_read_idx];
tty->rx_read_idx =
(tty->rx_read_idx + 1) % EC_TTY_RX_BUFFER_SIZE;
}
tty_flip_buffer_push(tty->tty);
}
}
tty->timer.expires += 1;
add_timer(&tty->timer);
}
/******************************************************************************
* Device callbacks
*****************************************************************************/
static int ec_tty_open(struct tty_struct *tty, struct file *file)
{
ec_tty_t *t;
int line = tty->index;
#if EC_TTY_DEBUG >= 1
printk(KERN_INFO PFX "%s(tty=%p, file=%p): Opening line %i.\n",
__func__, tty, file, line);
#endif
if (line < 0 || line >= EC_TTY_MAX_DEVICES) {
tty->driver_data = NULL;
return -ENXIO;
}
t = ttys[line];
if (!t) {
tty->driver_data = NULL;
return -ENXIO;
}
if (!t->tty) {
t->tty = tty;
tty->driver_data = t;
}
down(&t->sem);
t->open_count++;
up(&t->sem);
return 0;
}
/*****************************************************************************/
static void ec_tty_close(struct tty_struct *tty, struct file *file)
{
ec_tty_t *t = (ec_tty_t *) tty->driver_data;
#if EC_TTY_DEBUG >= 1
printk(KERN_INFO PFX "%s(tty=%p, file=%p): Closing line %i.\n",
__func__, tty, file, tty->index);
#endif
if (t) {
down(&t->sem);
if (--t->open_count == 0) {
t->tty = NULL;
}
up(&t->sem);
}
}
/*****************************************************************************/
static int ec_tty_write(
struct tty_struct *tty,
const unsigned char *buffer,
int count
)
{
ec_tty_t *t = (ec_tty_t *) tty->driver_data;
unsigned int data_size, i;
#if EC_TTY_DEBUG >= 1
printk(KERN_INFO PFX "%s(count=%i)\n", __func__, count);
#endif
if (count <= 0) {
return 0;
}
data_size = min(ec_tty_tx_space(t), (unsigned int) count);
for (i = 0; i < data_size; i++) {
t->tx_buffer[t->tx_write_idx] = buffer[i];
t->tx_write_idx = (t->tx_write_idx + 1) % EC_TTY_TX_BUFFER_SIZE;
}
#if EC_TTY_DEBUG >= 1
printk(KERN_INFO PFX "%s(): %u bytes written.\n", __func__, data_size);
#endif
return data_size;
}
/*****************************************************************************/
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 26)
static int ec_tty_put_char(struct tty_struct *tty, unsigned char ch)
#else
static void ec_tty_put_char(struct tty_struct *tty, unsigned char ch)
#endif
{
ec_tty_t *t = (ec_tty_t *) tty->driver_data;
#if EC_TTY_DEBUG >= 1
printk(KERN_INFO PFX "%s(): c=%02x.\n", __func__, (unsigned int) ch);
#endif
if (ec_tty_tx_space(t)) {
t->tx_buffer[t->tx_write_idx] = ch;
t->tx_write_idx = (t->tx_write_idx + 1) % EC_TTY_TX_BUFFER_SIZE;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 26)
return 1;
#endif
} else {
printk(KERN_WARNING PFX "%s(): Dropped a byte!\n", __func__);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 26)
return 0;
#endif
}
}
/*****************************************************************************/
static int ec_tty_write_room(struct tty_struct *tty)
{
ec_tty_t *t = (ec_tty_t *) tty->driver_data;
int ret = ec_tty_tx_space(t);
#if EC_TTY_DEBUG >= 2
printk(KERN_INFO PFX "%s() = %i.\n", __func__, ret);
#endif
return ret;
}
/*****************************************************************************/
static int ec_tty_chars_in_buffer(struct tty_struct *tty)
{
ec_tty_t *t = (ec_tty_t *) tty->driver_data;
int ret;
#if EC_TTY_DEBUG >= 2
printk(KERN_INFO PFX "%s().\n", __func__);
#endif
ret = ec_tty_tx_size(t);
#if EC_TTY_DEBUG >= 2
printk(KERN_INFO PFX "%s() = %i.\n", __func__, ret);
#endif
return ret;
}
/*****************************************************************************/
static void ec_tty_flush_buffer(struct tty_struct *tty)
{
#if EC_TTY_DEBUG >= 2
printk(KERN_INFO PFX "%s().\n", __func__);
#endif
// FIXME empty ring buffer
}
/*****************************************************************************/
static int ec_tty_ioctl(struct tty_struct *tty, struct file *file,
unsigned int cmd, unsigned long arg)
{
ec_tty_t *t = (ec_tty_t *) tty->driver_data;
int ret = -ENOTTY;
#if EC_TTY_DEBUG >= 2
printk(KERN_INFO PFX "%s(tty=%p, file=%p, cmd=%08x, arg=%08lx).\n",
__func__, tty, file, cmd, arg);
printk(KERN_INFO PFX "decoded: type=%02x nr=%u\n",
_IOC_TYPE(cmd), _IOC_NR(cmd));
#endif
switch (cmd) {
case TIOCGSERIAL:
if (access_ok(VERIFY_WRITE,
(void *) arg, sizeof(struct serial_struct))) {
ret = ec_tty_get_serial_info(t, (struct serial_struct *) arg);
} else {
ret = -EFAULT;
}
break;
default:
#if EC_TTY_DEBUG >= 2
printk(KERN_INFO PFX "no ioctl() -> handled by tty core!\n");
#endif
ret = -ENOIOCTLCMD;
break;
}
return ret;
}
/*****************************************************************************/
static void ec_tty_set_termios(struct tty_struct *tty,
struct ktermios *old_termios)
{
ec_tty_t *t = (ec_tty_t *) tty->driver_data;
int ret;
#if EC_TTY_DEBUG >= 2
printk(KERN_INFO PFX "%s().\n", __func__);
#endif
if (tty->termios->c_cflag == old_termios->c_cflag)
return;
#if EC_TTY_DEBUG >= 2
printk(KERN_INFO "cflag changed from %x to %x.\n",
old_termios->c_cflag, tty->termios->c_cflag);
#endif
ret = t->ops.cflag_changed(t->cb_data, tty->termios->c_cflag);
if (ret) {
printk(KERN_ERR PFX "ERROR: cflag 0x%x not accepted.\n",
tty->termios->c_cflag);
tty->termios->c_cflag = old_termios->c_cflag;
}
}
/*****************************************************************************/
static void ec_tty_stop(struct tty_struct *tty)
{
#if EC_TTY_DEBUG >= 2
printk(KERN_INFO PFX "%s().\n", __func__);
#endif
}
/*****************************************************************************/
static void ec_tty_start(struct tty_struct *tty)
{
#if EC_TTY_DEBUG >= 2
printk(KERN_INFO PFX "%s().\n", __func__);
#endif
}
/*****************************************************************************/
static void ec_tty_hangup(struct tty_struct *tty)
{
#if EC_TTY_DEBUG >= 2
printk(KERN_INFO PFX "%s().\n", __func__);
#endif
}
/*****************************************************************************/
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 27)
static int ec_tty_break(struct tty_struct *tty, int break_state)
#else
static void ec_tty_break(struct tty_struct *tty, int break_state)
#endif
{
#if EC_TTY_DEBUG >= 2
printk(KERN_INFO PFX "%s(break_state = %i).\n", __func__, break_state);
#endif
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 27)
return -EIO; // not implemented
#endif
}
/*****************************************************************************/
static void ec_tty_send_xchar(struct tty_struct *tty, char ch)
{
#if EC_TTY_DEBUG >= 2
printk(KERN_INFO PFX "%s(ch=%02x).\n", __func__, (unsigned int) ch);
#endif
}
/*****************************************************************************/
static void ec_tty_wait_until_sent(struct tty_struct *tty, int timeout)
{
#if EC_TTY_DEBUG >= 2
printk(KERN_INFO PFX "%s(timeout=%i).\n", __func__, timeout);
#endif
}
/*****************************************************************************/
static const struct tty_operations ec_tty_ops = {
.open = ec_tty_open,
.close = ec_tty_close,
.write = ec_tty_write,
.put_char = ec_tty_put_char,
.write_room = ec_tty_write_room,
.chars_in_buffer = ec_tty_chars_in_buffer,
.flush_buffer = ec_tty_flush_buffer,
.ioctl = ec_tty_ioctl,
.set_termios = ec_tty_set_termios,
.stop = ec_tty_stop,
.start = ec_tty_start,
.hangup = ec_tty_hangup,
.break_ctl = ec_tty_break,
.send_xchar = ec_tty_send_xchar,
.wait_until_sent = ec_tty_wait_until_sent,
};
/******************************************************************************
* Public functions and methods
*****************************************************************************/
ec_tty_t *ectty_create(const ec_tty_operations_t *ops, void *cb_data)
{
ec_tty_t *tty;
int minor, ret;
if (down_interruptible(&tty_sem)) {
return ERR_PTR(-EINTR);
}
for (minor = 0; minor < EC_TTY_MAX_DEVICES; minor++) {
if (!ttys[minor]) {
printk(KERN_INFO PFX "Creating TTY interface %i.\n", minor);
tty = kmalloc(sizeof(ec_tty_t), GFP_KERNEL);
if (!tty) {
up(&tty_sem);
printk(KERN_ERR PFX "Failed to allocate memory.\n");
return ERR_PTR(-ENOMEM);
}
ret = ec_tty_init(tty, minor, ops, cb_data);
if (ret) {
up(&tty_sem);
kfree(tty);
return ERR_PTR(ret);
}
ttys[minor] = tty;
up(&tty_sem);
return tty;
}
}
up(&tty_sem);
printk(KERN_ERR PFX "No free interfaces avaliable.\n");
return ERR_PTR(-EBUSY);
}
/*****************************************************************************/
void ectty_free(ec_tty_t *tty)
{
printk(KERN_INFO PFX "Freeing TTY interface %i.\n", tty->minor);
ec_tty_clear(tty);
ttys[tty->minor] = NULL;
kfree(tty);
}
/*****************************************************************************/
unsigned int ectty_tx_data(ec_tty_t *tty, uint8_t *buffer, size_t size)
{
unsigned int data_size = min(ec_tty_tx_size(tty), size), i;
if (data_size) {
#if EC_TTY_DEBUG >= 1
printk(KERN_INFO PFX "Fetching %u bytes to send.\n", data_size);
#endif
}
for (i = 0; i < data_size; i++) {
buffer[i] = tty->tx_buffer[tty->tx_read_idx];
tty->tx_read_idx = (tty->tx_read_idx + 1) % EC_TTY_TX_BUFFER_SIZE;
}
if (data_size) {
tty->wakeup = 1;
}
return data_size;
}
/*****************************************************************************/
void ectty_rx_data(ec_tty_t *tty, const uint8_t *buffer, size_t size)
{
size_t to_recv;
if (size) {
unsigned int i;
#if EC_TTY_DEBUG >= 1
printk(KERN_INFO PFX "Received %u bytes.\n", size);
#endif
to_recv = min(ec_tty_rx_space(tty), size);
if (to_recv < size) {
printk(KERN_WARNING PFX "Dropping %u bytes.\n", size - to_recv);
}
for (i = 0; i < size; i++) {
tty->rx_buffer[tty->rx_write_idx] = buffer[i];
tty->rx_write_idx =
(tty->rx_write_idx + 1) % EC_TTY_RX_BUFFER_SIZE;
}
}
}
/*****************************************************************************/
/** \cond */
module_init(ec_tty_init_module);
module_exit(ec_tty_cleanup_module);
EXPORT_SYMBOL(ectty_create);
EXPORT_SYMBOL(ectty_free);
EXPORT_SYMBOL(ectty_tx_data);
EXPORT_SYMBOL(ectty_rx_data);
/** \endcond */
/*****************************************************************************/