text: /*
   * USB ZyXEL omni.net LCD PLUS driver
   *
   *	This program 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.
   *
   * See Documentation/usb/usb-serial.txt for more information on using this
   * driver
   *
   * Please report both successes and troubles to the author at omninet@kroah.com
   *
   * (05/30/2001) gkh
   *	switched from using spinlock to a semaphore, which fixes lots of
   *	problems.
   *
   * (04/08/2001) gb
   *	Identify version on module load.
   *
   * (11/01/2000) Adam J. Richter
   *	usb_device_id table support
   *
   * (10/05/2000) gkh
   *	Fixed bug with urb->dev not being set properly, now that the usb
   *	core needs it.
   *
   * (08/28/2000) gkh
   *	Added locks for SMP safeness.
   *	Fixed MOD_INC and MOD_DEC logic and the ability to open a port more
   *	than once.
   *	Fixed potential race in omninet_write_bulk_callback
   *
   * (07/19/2000) gkh
   *	Added module_init and module_exit functions to handle the fact that this
   *	driver is a loadable module now.
   *
   */
  
  #include <linux/kernel.h>
  #include <linux/errno.h>
  #include <linux/init.h>
  #include <linux/slab.h>
  #include <linux/tty.h>
  #include <linux/tty_driver.h>
  #include <linux/tty_flip.h>
  #include <linux/module.h>
  #include <linux/spinlock.h>
  #include <linux/uaccess.h>
  #include <linux/usb.h>
  #include <linux/usb/serial.h>
  
  static int debug;
  
  /*
   * Version Information
   */
  #define DRIVER_VERSION "v1.1"
  #define DRIVER_AUTHOR "Alessandro Zummo"
  #define DRIVER_DESC "USB ZyXEL omni.net LCD PLUS Driver"
  
  #define ZYXEL_VENDOR_ID		0x0586
  #define ZYXEL_OMNINET_ID	0x1000
  /* This one seems to be a re-branded ZyXEL device */
  #define BT_IGNITIONPRO_ID	0x2000
  
  /* function prototypes */
  static int  omninet_open(struct tty_struct *tty, struct usb_serial_port *port);
  static void omninet_close(struct usb_serial_port *port);
  static void omninet_read_bulk_callback(struct urb *urb);
  static void omninet_write_bulk_callback(struct urb *urb);
  static int  omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
  				const unsigned char *buf, int count);
  static int  omninet_write_room(struct tty_struct *tty);
  static void omninet_disconnect(struct usb_serial *serial);
  static void omninet_release(struct usb_serial *serial);
  static int omninet_attach(struct usb_serial *serial);
  
  static struct usb_device_id id_table[] = {
  	{ USB_DEVICE(ZYXEL_VENDOR_ID, ZYXEL_OMNINET_ID) },
  	{ USB_DEVICE(ZYXEL_VENDOR_ID, BT_IGNITIONPRO_ID) },
  	{ }						/* Terminating entry */
  };
  
  MODULE_DEVICE_TABLE(usb, id_table);
  
  static struct usb_driver omninet_driver = {
  	.name =		"omninet",
  	.probe =	usb_serial_probe,
  	.disconnect =	usb_serial_disconnect,
  	.id_table =	id_table,
  	.no_dynamic_id = 	1,
  };
  
  
  static struct usb_serial_driver zyxel_omninet_device = {
  	.driver = {
  		.owner =	THIS_MODULE,
  		.name =		"omninet",
  	},
  	.description =		"ZyXEL - omni.net lcd plus usb",
  	.usb_driver =		&omninet_driver,
  	.id_table =		id_table,
  	.num_ports =		1,
  	.attach =		omninet_attach,
  	.open =			omninet_open,
  	.close =		omninet_close,
  	.write =		omninet_write,
  	.write_room =		omninet_write_room,
  	.read_bulk_callback =	omninet_read_bulk_callback,
  	.write_bulk_callback =	omninet_write_bulk_callback,
  	.disconnect =		omninet_disconnect,
  	.release =		omninet_release,
  };
  
  
  /* The protocol.
   *
   * The omni.net always exchange 64 bytes of data with the host. The first
   * four bytes are the control header, you can see it in the above structure.
   *
   * oh_seq is a sequence number. Don't know if/how it's used.
   * oh_len is the length of the data bytes in the packet.
   * oh_xxx Bit-mapped, related to handshaking and status info.
   *	I normally set it to 0x03 in trasmitted frames.
   *	7: Active when the TA is in a CONNECTed state.
   *	6: unknown
   *	5: handshaking, unknown
   *	4: handshaking, unknown
   *	3: unknown, usually 0
   *	2: unknown, usually 0
   *	1: handshaking, unknown, usually set to 1 in trasmitted frames
   *	0: handshaking, unknown, usually set to 1 in trasmitted frames
   * oh_pad Probably a pad byte.
   *
   * After the header you will find data bytes if oh_len was greater than zero.
   *
   */
  
  struct omninet_header {
  	__u8	oh_seq;
  	__u8	oh_len;
  	__u8	oh_xxx;
  	__u8	oh_pad;
  };
  
  struct omninet_data {
  	__u8	od_outseq;	/* Sequence number for bulk_out URBs */
  };
  
  static int omninet_attach(struct usb_serial *serial)
  {
  	struct omninet_data *od;
  	struct usb_serial_port *port = serial->port[0];
  
  	od = kmalloc(sizeof(struct omninet_data), GFP_KERNEL);
  	if (!od) {
  		dev_err(&port->dev, "%s- kmalloc(%Zd) failed.\n",
  			__func__, sizeof(struct omninet_data));
  		return -ENOMEM;
  	}
  	usb_set_serial_port_data(port, od);
  	return 0;
  }
  
  static int omninet_open(struct tty_struct *tty, struct usb_serial_port *port)
  {
  	struct usb_serial	*serial = port->serial;
  	struct usb_serial_port	*wport;
  	int			result = 0;
  
  	dbg("%s - port %d", __func__, port->number);
  
  	wport = serial->port[1];
  	tty_port_tty_set(&wport->port, tty);
  
  	/* Start reading from the device */
  	usb_fill_bulk_urb(port->read_urb, serial->dev,
  			usb_rcvbulkpipe(serial->dev,
  				port->bulk_in_endpointAddress),
  			port->read_urb->transfer_buffer,
  			port->read_urb->transfer_buffer_length,
  			omninet_read_bulk_callback, port);
  	result = usb_submit_urb(port->read_urb, GFP_KERNEL);
  	if (result)
  		dev_err(&port->dev,
  			"%s - failed submitting read urb, error %d\n",
  			__func__, result);
  	return result;
  }
  
  static void omninet_close(struct usb_serial_port *port)
  {
  	dbg("%s - port %d", __func__, port->number);
  	usb_kill_urb(port->read_urb);
  }
  
  
  #define OMNINET_DATAOFFSET	0x04
  #define OMNINET_HEADERLEN	sizeof(struct omninet_header)
  #define OMNINET_BULKOUTSIZE 	(64 - OMNINET_HEADERLEN)
  
  static void omninet_read_bulk_callback(struct urb *urb)
  {
  	struct usb_serial_port 	*port 	= urb->context;
  	unsigned char 		*data 	= urb->transfer_buffer;
  	struct omninet_header 	*header = (struct omninet_header *) &data[0];
  	int status = urb->status;
  	int result;
  	int i;
  
  	dbg("%s - port %d", __func__, port->number);
  
  	if (status) {
  		dbg("%s - nonzero read bulk status received: %d",
  		    __func__, status);
  		return;
  	}
  
  	if (debug && header->oh_xxx != 0x30) {
  		if (urb->actual_length) {
  			printk(KERN_DEBUG __FILE__
  					": omninet_read %d: ", header->oh_len);
  			for (i = 0; i < (header->oh_len +
  						OMNINET_HEADERLEN); i++)
  				printk("%.2x ", data[i]);
  			printk("\n");
  		}
  	}
  
  	if (urb->actual_length && header->oh_len) {
  		struct tty_struct *tty = tty_port_tty_get(&port->port);
  		tty_insert_flip_string(tty, data + OMNINET_DATAOFFSET,
  							header->oh_len);
  		tty_flip_buffer_push(tty);
  		tty_kref_put(tty);
  	}
  
  	/* Continue trying to always read  */
  	usb_fill_bulk_urb(urb, port->serial->dev,
  			usb_rcvbulkpipe(port->serial->dev,
  					port->bulk_in_endpointAddress),
  			urb->transfer_buffer, urb->transfer_buffer_length,
  			omninet_read_bulk_callback, port);
  	result = usb_submit_urb(urb, GFP_ATOMIC);
  	if (result)
  		dev_err(&port->dev,
  			"%s - failed resubmitting read urb, error %d\n",
  			__func__, result);
  
  	return;
  }
  
  static int omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
  					const unsigned char *buf, int count)
  {
  	struct usb_serial *serial = port->serial;
  	struct usb_serial_port *wport = serial->port[1];
  
  	struct omninet_data *od = usb_get_serial_port_data(port);
  	struct omninet_header *header = (struct omninet_header *)
  					wport->write_urb->transfer_buffer;
  
  	int			result;
  
  	dbg("%s - port %d", __func__, port->number);
  
  	if (count == 0) {
  		dbg("%s - write request of 0 bytes", __func__);
  		return 0;
  	}
  
  	spin_lock_bh(&wport->lock);
  	if (wport->write_urb_busy) {
  		spin_unlock_bh(&wport->lock);
  		dbg("%s - already writing", __func__);
  		return 0;
  	}
  	wport->write_urb_busy = 1;
  	spin_unlock_bh(&wport->lock);
  
  	count = (count > OMNINET_BULKOUTSIZE) ? OMNINET_BULKOUTSIZE : count;
  
  	memcpy(wport->write_urb->transfer_buffer + OMNINET_DATAOFFSET,
  								buf, count);
  
  	usb_serial_debug_data(debug, &port->dev, __func__, count,
  					wport->write_urb->transfer_buffer);
  
  	header->oh_seq 	= od->od_outseq++;
  	header->oh_len 	= count;
  	header->oh_xxx  = 0x03;
  	header->oh_pad 	= 0x00;
  
  	/* send the data out the bulk port, always 64 bytes */
  	wport->write_urb->transfer_buffer_length = 64;
  
  	wport->write_urb->dev = serial->dev;
  	result = usb_submit_urb(wport->write_urb, GFP_ATOMIC);
  	if (result) {
  		wport->write_urb_busy = 0;
  		dev_err(&port->dev,
  			"%s - failed submitting write urb, error %d\n",
  			__func__, result);
  	} else
  		result = count;
  
  	return result;
  }
  
  
  static int omninet_write_room(struct tty_struct *tty)
  {
  	struct usb_serial_port *port = tty->driver_data;
  	struct usb_serial 	*serial = port->serial;
  	struct usb_serial_port 	*wport 	= serial->port[1];
  
  	int room = 0; /* Default: no room */
  
  	/* FIXME: no consistent locking for write_urb_busy */
  	if (wport->write_urb_busy)
  		room = wport->bulk_out_size - OMNINET_HEADERLEN;
  
  	dbg("%s - returns %d", __func__, room);
  
  	return room;
  }
  
  static void omninet_write_bulk_callback(struct urb *urb)
  {
  /*	struct omninet_header	*header = (struct omninet_header  *)
  						urb->transfer_buffer; */
  	struct usb_serial_port 	*port   =  urb->context;
  	int status = urb->status;
  
  	dbg("%s - port %0x\n", __func__, port->number);
  
  	port->write_urb_busy = 0;
  	if (status) {
  		dbg("%s - nonzero write bulk status received: %d",
  		    __func__, status);
  		return;
  	}
  
  	usb_serial_port_softint(port);
  }
  
  
  static void omninet_disconnect(struct usb_serial *serial)
  {
  	struct usb_serial_port *wport = serial->port[1];
  
  	dbg("%s", __func__);
  
  	usb_kill_urb(wport->write_urb);
  }
  
  
  static void omninet_release(struct usb_serial *serial)
  {
  	struct usb_serial_port *port = serial->port[0];
  
  	dbg("%s", __func__);
  
  	kfree(usb_get_serial_port_data(port));
  }
  
  
  static int __init omninet_init(void)
  {
  	int retval;
  	retval = usb_serial_register(&zyxel_omninet_device);
  	if (retval)
  		goto failed_usb_serial_register;
  	retval = usb_register(&omninet_driver);
  	if (retval)
  		goto failed_usb_register;
  	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
  	       DRIVER_DESC "\n");
  	return 0;
  failed_usb_register:
  	usb_serial_deregister(&zyxel_omninet_device);
  failed_usb_serial_register:
  	return retval;
  }
  
  
  static void __exit omninet_exit(void)
  {
  	usb_deregister(&omninet_driver);
  	usb_serial_deregister(&zyxel_omninet_device);
  }
  
  
  module_init(omninet_init);
  module_exit(omninet_exit);
  
  MODULE_AUTHOR(DRIVER_AUTHOR);
  MODULE_DESCRIPTION(DRIVER_DESC);
  MODULE_LICENSE("GPL");
  
  module_param(debug, bool, S_IRUGO | S_IWUSR);
  MODULE_PARM_DESC(debug, "Debug enabled or not");
  