#include <linux/ioctl.h>
 #include <linux/serial.h>
 #include <linux/circ_buf.h>
+#include <linux/mutex.h>
 #include <asm/uaccess.h>
 #include <asm/semaphore.h>
 #include <linux/usb.h>
 };
 
 struct ti_device {
-       struct semaphore        td_open_close_sem;
+       struct mutex            td_open_close_lock;
        int                     td_open_port_count;
        struct usb_serial       *td_serial;
        int                     td_is_3410;
                dev_err(&dev->dev, "%s - out of memory\n", __FUNCTION__);
                return -ENOMEM;
        }
-       sema_init(&tdev->td_open_close_sem, 1);
+       mutex_init(&tdev->td_open_close_lock);
        tdev->td_serial = serial;
        usb_set_serial_data(serial, tdev);
 
        tdev = tport->tp_tdev;
 
        /* only one open on any port on a device at a time */
-       if (down_interruptible(&tdev->td_open_close_sem))
+       if (mutex_lock_interruptible(&tdev->td_open_close_lock))
                return -ERESTARTSYS;
 
        if (port->tty)
                if (!urb) {
                        dev_err(&port->dev, "%s - no interrupt urb\n", __FUNCTION__);
                        status = -EINVAL;
-                       goto up_sem;
+                       goto release_lock;
                }
                urb->complete = ti_interrupt_callback;
                urb->context = tdev;
                status = usb_submit_urb(urb, GFP_KERNEL);
                if (status) {
                        dev_err(&port->dev, "%s - submit interrupt urb failed, %d\n", __FUNCTION__, status);
-                       goto up_sem;
+                       goto release_lock;
                }
        }
 
        tport->tp_is_open = 1;
        ++tdev->td_open_port_count;
 
-       goto up_sem;
+       goto release_lock;
 
 unlink_int_urb:
        if (tdev->td_open_port_count == 0)
                usb_kill_urb(port->serial->port[0]->interrupt_in_urb);
-up_sem:
-       up(&tdev->td_open_close_sem);
+release_lock:
+       mutex_unlock(&tdev->td_open_close_lock);
        dbg("%s - exit %d", __FUNCTION__, status);
        return status;
 }
        struct ti_port *tport;
        int port_number;
        int status;
-       int do_up;
+       int do_unlock;
 
        dbg("%s - port %d", __FUNCTION__, port->number);
                         
        if (status)
                dev_err(&port->dev, "%s - cannot send close port command, %d\n" , __FUNCTION__, status);
 
-       /* if down is interrupted, continue anyway */
-       do_up = !down_interruptible(&tdev->td_open_close_sem);
+       /* if mutex_lock is interrupted, continue anyway */
+       do_unlock = !mutex_lock_interruptible(&tdev->td_open_close_lock);
        --tport->tp_tdev->td_open_port_count;
        if (tport->tp_tdev->td_open_port_count <= 0) {
                /* last port is closed, shut down interrupt urb */
                usb_kill_urb(port->serial->port[0]->interrupt_in_urb);
                tport->tp_tdev->td_open_port_count = 0;
        }
-       if (do_up)
-               up(&tdev->td_open_close_sem);
+       if (do_unlock)
+               mutex_unlock(&tdev->td_open_close_lock);
 
        dbg("%s - exit", __FUNCTION__);
 }