+#define URB_TRANSFER_BUFFER_SIZE 4096
+#define NUM_READ_URBS 4
+#define NUM_WRITE_URBS 4
+#define NUM_BULK_EPS 3
+#define MAX_BULK_EPS 6
+
+/* if overridden by the user, then use their value for the size of the
+ * read and write urbs, and the number of endpoints */
+static int buffer_size = URB_TRANSFER_BUFFER_SIZE;
+static int endpoints = NUM_BULK_EPS;
+static int debug;
+struct airprime_private {
+ spinlock_t lock;
+ int outstanding_urbs;
+ int throttled;
+ struct urb *read_urbp[NUM_READ_URBS];
+};
+
+static void airprime_read_bulk_callback(struct urb *urb)
+{
+ struct usb_serial_port *port = urb->context;
+ unsigned char *data = urb->transfer_buffer;
+ struct tty_struct *tty;
+ int result;
+
+ dbg("%s - port %d", __FUNCTION__, port->number);
+
+ if (urb->status) {
+ dbg("%s - nonzero read bulk status received: %d",
+ __FUNCTION__, urb->status);
+ /* something happened, so free up the memory for this urb */
+ if (urb->transfer_buffer) {
+ kfree (urb->transfer_buffer);
+ urb->transfer_buffer = NULL;
+ }
+ return;
+ }
+ usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);
+
+ tty = port->tty;
+ if (tty && urb->actual_length) {
+ tty_insert_flip_string (tty, data, urb->actual_length);
+ tty_flip_buffer_push (tty);
+ }
+
+ result = usb_submit_urb (urb, GFP_ATOMIC);
+ if (result)
+ dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n",
+ __FUNCTION__, result);
+ return;
+}
+
+static void airprime_write_bulk_callback(struct urb *urb)
+{
+ struct usb_serial_port *port = urb->context;
+ struct airprime_private *priv = usb_get_serial_port_data(port);
+ unsigned long flags;
+
+ dbg("%s - port %d", __FUNCTION__, port->number);
+
+ /* free up the transfer buffer, as usb_free_urb() does not do this */
+ kfree (urb->transfer_buffer);
+
+ if (urb->status)
+ dbg("%s - nonzero write bulk status received: %d",
+ __FUNCTION__, urb->status);
+ spin_lock_irqsave(&priv->lock, flags);
+ --priv->outstanding_urbs;
+ spin_unlock_irqrestore(&priv->lock, flags);
+
+ usb_serial_port_softint(port);
+}
+
+static int airprime_open(struct usb_serial_port *port, struct file *filp)
+{
+ struct airprime_private *priv = usb_get_serial_port_data(port);
+ struct usb_serial *serial = port->serial;
+ struct urb *urb;
+ char *buffer = NULL;
+ int i;
+ int result = 0;
+
+ dbg("%s - port %d", __FUNCTION__, port->number);
+
+ /* initialize our private data structure if it isn't already created */
+ if (!priv) {
+ priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv) {
+ result = -ENOMEM;
+ goto out;
+ }
+ spin_lock_init(&priv->lock);
+ usb_set_serial_port_data(port, priv);
+ }
+
+ for (i = 0; i < NUM_READ_URBS; ++i) {
+ buffer = kmalloc(buffer_size, GFP_KERNEL);
+ if (!buffer) {
+ dev_err(&port->dev, "%s - out of memory.\n",
+ __FUNCTION__);
+ result = -ENOMEM;
+ goto errout;
+ }
+ urb = usb_alloc_urb(0, GFP_KERNEL);
+ if (!urb) {
+ kfree(buffer);
+ dev_err(&port->dev, "%s - no more urbs?\n",
+ __FUNCTION__);
+ result = -ENOMEM;
+ goto errout;
+ }
+ usb_fill_bulk_urb(urb, serial->dev,
+ usb_rcvbulkpipe(serial->dev,
+ port->bulk_out_endpointAddress),
+ buffer, buffer_size,
+ airprime_read_bulk_callback, port);
+ result = usb_submit_urb(urb, GFP_KERNEL);
+ if (result) {
+ dev_err(&port->dev,
+ "%s - failed submitting read urb %d for port %d, error %d\n",
+ __FUNCTION__, i, port->number, result);
+ goto errout;
+ }
+ /* remember this urb so we can kill it when the port is closed */
+ priv->read_urbp[i] = urb;
+ }
+ goto out;
+
+ errout:
+ /* some error happened, cancel any submitted urbs and clean up anything that
+ got allocated successfully */
+
+ for ( ; i >= 0; --i) {
+ urb = priv->read_urbp[i];
+ if (urb) {
+ /* This urb was submitted successfully. So we have to
+ cancel it.
+ Unlinking the urb will invoke read_bulk_callback()
+ with an error status, so its transfer buffer will
+ be freed there */
+ if (usb_unlink_urb (urb) != -EINPROGRESS) {
+ /* comments in drivers/usb/core/urb.c say this
+ can only happen if the urb was never submitted,
+ or has completed already.
+ Either way we may have to free the transfer
+ buffer here. */
+ if (urb->transfer_buffer) {
+ kfree (urb->transfer_buffer);
+ urb->transfer_buffer = NULL;
+ }
+ }
+ usb_free_urb (urb);
+ }
+ }
+
+ out:
+ return result;
+}
+
+static void airprime_close(struct usb_serial_port *port, struct file * filp)
+{
+ struct airprime_private *priv = usb_get_serial_port_data(port);
+ int i;
+
+ dbg("%s - port %d", __FUNCTION__, port->number);
+
+ /* killing the urb will invoke read_bulk_callback() with an error status,
+ so the transfer buffer will be freed there */
+ for (i = 0; i < NUM_READ_URBS; ++i) {
+ usb_kill_urb (priv->read_urbp[i]);
+ usb_free_urb (priv->read_urbp[i]);
+ }
+
+ /* free up private structure */
+ kfree (priv);
+ usb_set_serial_port_data(port, NULL);
+}
+
+static int airprime_write(struct usb_serial_port *port,
+ const unsigned char *buf, int count)
+{
+ struct airprime_private *priv = usb_get_serial_port_data(port);
+ struct usb_serial *serial = port->serial;
+ struct urb *urb;
+ unsigned char *buffer;
+ unsigned long flags;
+ int status;
+ dbg("%s - port %d", __FUNCTION__, port->number);
+
+ spin_lock_irqsave(&priv->lock, flags);
+ if (priv->outstanding_urbs > NUM_WRITE_URBS) {
+ spin_unlock_irqrestore(&priv->lock, flags);
+ dbg("%s - write limit hit\n", __FUNCTION__);
+ return 0;
+ }
+ spin_unlock_irqrestore(&priv->lock, flags);
+ buffer = kmalloc(count, GFP_ATOMIC);
+ if (!buffer) {
+ dev_err(&port->dev, "out of memory\n");
+ return -ENOMEM;
+ }
+ urb = usb_alloc_urb(0, GFP_ATOMIC);
+ if (!urb) {
+ dev_err(&port->dev, "no more free urbs\n");
+ kfree (buffer);
+ return -ENOMEM;
+ }
+ memcpy (buffer, buf, count);
+
+ usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, buffer);
+
+ usb_fill_bulk_urb(urb, serial->dev,
+ usb_sndbulkpipe(serial->dev,
+ port->bulk_out_endpointAddress),
+ buffer, count,
+ airprime_write_bulk_callback, port);
+
+ /* send it down the pipe */
+ status = usb_submit_urb(urb, GFP_ATOMIC);
+ if (status) {
+ dev_err(&port->dev,
+ "%s - usb_submit_urb(write bulk) failed with status = %d\n",
+ __FUNCTION__, status);
+ count = status;
+ kfree (buffer);
+ } else {
+ spin_lock_irqsave(&priv->lock, flags);
+ ++priv->outstanding_urbs;
+ spin_unlock_irqrestore(&priv->lock, flags);
+ }
+ /* we are done with this urb, so let the host driver
+ * really free it when it is finished with it */
+ usb_free_urb (urb);
+ return count;
+}
+