From fdad28ad05659012850da86013f010c93a254a01 Mon Sep 17 00:00:00 2001
From: Florian Pose <fp@igh.de>
Date: Tue, 1 Dec 2009 17:35:33 +0100
Subject: [PATCH] Register a TTY driver with one device.

---
 tty/module.c | 91 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 91 insertions(+)

diff --git a/tty/module.c b/tty/module.c
index d1602dd7..ac9c73ad 100644
--- a/tty/module.c
+++ b/tty/module.c
@@ -35,6 +35,9 @@
 
 #include <linux/module.h>
 #include <linux/err.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/termios.h>
 
 #include "../master/globals.h"
 
@@ -58,6 +61,27 @@ MODULE_VERSION(EC_MASTER_VERSION);
 module_param_named(debug_level, debug_level, uint, S_IRUGO);
 MODULE_PARM_DESC(debug_level, "Debug level");
 
+struct tty_driver *tty_driver = NULL;
+struct device *tty_device = NULL;
+
+static int ec_tty_open(struct tty_struct *, struct file *);
+static void ec_tty_close(struct tty_struct *, struct file *);
+static int ec_tty_write(struct tty_struct *, const unsigned char *, int);
+
+static const struct tty_operations ec_tty_ops = {
+    .open = ec_tty_open,
+    .close = ec_tty_close,
+    .write = ec_tty_write,
+};
+
+static struct ktermios ec_tty_std_termios = {
+    .c_iflag = ICRNL | IXON,
+    .c_oflag = OPOST | ONLCR,
+    .c_cflag = B38400 | CS8 | CREAD | HUPCL,
+    .c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK | ECHOCTL | ECHOKE | IEXTEN,
+    .c_cc = INIT_C_CC,
+};
+
 /** \endcond */
 
 /*****************************************************************************/
@@ -72,6 +96,45 @@ int __init ec_tty_init_module(void)
 
     EC_INFO("TTY driver %s\n", EC_MASTER_VERSION);
 
+    tty_driver = alloc_tty_driver(1);
+    if (!tty_driver) {
+        EC_ERR("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_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
+    tty_set_operations(tty_driver, &ec_tty_ops);
+
+    ret = tty_register_driver(tty_driver);
+    if (ret) {
+        EC_ERR("Failed to register tty driver.\n");
+        goto out_put;
+    }
+
+    tty_device = tty_register_device(tty_driver, 0, NULL);
+    if (IS_ERR(tty_device)) {
+        EC_ERR("Failed to register tty device.\n");
+        ret = PTR_ERR(tty_device);
+        goto out_unreg;
+    }
+
+    return ret;
+        
+out_unreg:
+    tty_unregister_driver(tty_driver);
+out_put:
+    put_tty_driver(tty_driver);
+out_return:
     return ret;
 }
 
@@ -83,11 +146,39 @@ int __init ec_tty_init_module(void)
  */
 void __exit ec_tty_cleanup_module(void)
 {
+    tty_unregister_device(tty_driver, 0);
+    tty_unregister_driver(tty_driver);
+    put_tty_driver(tty_driver);
     EC_INFO("TTY module cleaned up.\n");
 }
 
 /*****************************************************************************/
 
+static int ec_tty_open(struct tty_struct *tty, struct file *file)
+{
+    return -EBUSY;
+}
+
+/*****************************************************************************/
+
+static void ec_tty_close(struct tty_struct *tty, struct file *file)
+{
+    return;
+}
+
+/*****************************************************************************/
+
+static int ec_tty_write(
+        struct tty_struct *tty,
+        const unsigned char *buffer,
+        int count
+        )
+{
+    return -EIO;
+}
+
+/*****************************************************************************/
+
 /** \cond */
 
 module_init(ec_tty_init_module);