[deliverable/linux.git] / drivers / usb / serial / aircable.c

/*
 * AIRcable USB Bluetooth Dongle Driver.
 *
 * Copyright (C) 2006 Manuel Francisco Naranjo (naranjo.manuel@gmail.com)
 * 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.
 *
 * The device works as an standard CDC device, it has 2 interfaces, the first
 * one is for firmware access and the second is the serial one.
 * The protocol is very simply, there are two posibilities reading or writing.
 * When writting the first urb must have a Header that starts with 0x20 0x29 the
 * next two bytes must say how much data will be sended.
 * When reading the process is almost equal except that the header starts with
 * 0x00 0x20.
 *
 * The device simply need some stuff to understand data comming from the usb
 * buffer: The First and Second byte is used for a Header, the Third and Fourth
 * tells the  device the amount of information the package holds.
 * Packages are 60 bytes long Header Stuff.
 * When writting to the device the first two bytes of the header are 0x20 0x29
 * When reading the bytes are 0x00 0x20, or 0x00 0x10, there is an strange
 * situation, when too much data arrives to the device because it sends the data
 * but with out the header. I will use a simply hack to override this situation,
 * if there is data coming that does not contain any header, then that is data
 * that must go directly to the tty, as there is no documentation about if there
 * is any other control code, I will simply check for the first
 * one.
 *
 * The driver registers himself with the USB-serial core and the USB Core. I had
 * to implement a probe function agains USB-serial, because other way, the
 * driver was attaching himself to both interfaces. I have tryed with different
 * configurations of usb_serial_driver with out exit, only the probe function
 * could handle this correctly.
 *
 * I have taken some info from a Greg Kroah-Hartman article:
 * http://www.linuxjournal.com/article/6573
 * And from Linux Device Driver Kit CD, which is a great work, the authors taken
 * the work to recompile lots of information an knowladge in drivers development
 * and made it all avaible inside a cd.
 * URL: http://kernel.org/pub/linux/kernel/people/gregkh/ddk/
 *
 */

#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/circ_buf.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>

static int debug;

/* Vendor and Product ID */
#define AIRCABLE_VID		0x16CA
#define AIRCABLE_USB_PID	0x1502

/* write buffer size defines */
#define AIRCABLE_BUF_SIZE	2048

/* Protocol Stuff */
#define HCI_HEADER_LENGTH	0x4
#define TX_HEADER_0		0x20
#define TX_HEADER_1		0x29
#define RX_HEADER_0		0x00
#define RX_HEADER_1		0x20
#define MAX_HCI_FRAMESIZE	60
#define HCI_COMPLETE_FRAME	64

/* rx_flags */
#define THROTTLED		0x01
#define ACTUALLY_THROTTLED	0x02

/*
 * Version Information
 */
#define DRIVER_VERSION "v1.0b2"
#define DRIVER_AUTHOR "Naranjo, Manuel Francisco <naranjo.manuel@gmail.com>"
#define DRIVER_DESC "AIRcable USB Driver"

/* ID table that will be registered with USB core */
static struct usb_device_id id_table [] = {
	{ USB_DEVICE(AIRCABLE_VID, AIRCABLE_USB_PID) },
	{ },
};
MODULE_DEVICE_TABLE(usb, id_table);


/* Internal Structure */
struct aircable_private {
	spinlock_t rx_lock;		/* spinlock for the receive lines */
	struct circ_buf *tx_buf;	/* write buffer */
	struct circ_buf *rx_buf;	/* read buffer */
	int rx_flags;			/* for throttilng */
	struct work_struct rx_work;	/* work cue for the receiving line */
	struct usb_serial_port *port;	/* USB port with which associated */
};

/* Private methods */

/* Circular Buffer Methods, code from ti_usb_3410_5052 used */
/*
 * serial_buf_clear
 *
 * Clear out all data in the circular buffer.
 */
static void serial_buf_clear(struct circ_buf *cb)
{
	cb->head = cb->tail = 0;
}

/*
 * serial_buf_alloc
 *
 * Allocate a circular buffer and all associated memory.
 */
static struct circ_buf *serial_buf_alloc(void)
{
	struct circ_buf *cb;
	cb = kmalloc(sizeof(struct circ_buf), GFP_KERNEL);
	if (cb == NULL)
		return NULL;
	cb->buf = kmalloc(AIRCABLE_BUF_SIZE, GFP_KERNEL);
	if (cb->buf == NULL) {
		kfree(cb);
		return NULL;
	}
	serial_buf_clear(cb);
	return cb;
}

/*
 * serial_buf_free
 *
 * Free the buffer and all associated memory.
 */
static void serial_buf_free(struct circ_buf *cb)
{
	kfree(cb->buf);
	kfree(cb);
}

/*
 * serial_buf_data_avail
 *
 * Return the number of bytes of data available in the circular
 * buffer.
 */
static int serial_buf_data_avail(struct circ_buf *cb)
{
	return CIRC_CNT(cb->head,cb->tail,AIRCABLE_BUF_SIZE);
}

/*
 * serial_buf_put
 *
 * Copy data data from a user buffer and put it into the circular buffer.
 * Restrict to the amount of space available.
 *
 * Return the number of bytes copied.
 */
static int serial_buf_put(struct circ_buf *cb, const char *buf, int count)
{
	int c, ret = 0;
	while (1) {
		c = CIRC_SPACE_TO_END(cb->head, cb->tail, AIRCABLE_BUF_SIZE);
		if (count < c)
			c = count;
		if (c <= 0)
			break;
		memcpy(cb->buf + cb->head, buf, c);
		cb->head = (cb->head + c) & (AIRCABLE_BUF_SIZE-1);
		buf += c;
		count -= c;
		ret= c;
	}
	return ret;
}

/*
 * serial_buf_get
 *
 * Get data from the circular buffer and copy to the given buffer.
 * Restrict to the amount of data available.
 *
 * Return the number of bytes copied.
 */
static int serial_buf_get(struct circ_buf *cb, char *buf, int count)
{
	int c, ret = 0;
	while (1) {
		c = CIRC_CNT_TO_END(cb->head, cb->tail, AIRCABLE_BUF_SIZE);
		if (count < c)
			c = count;
		if (c <= 0)
			break;
		memcpy(buf, cb->buf + cb->tail, c);
		cb->tail = (cb->tail + c) & (AIRCABLE_BUF_SIZE-1);
		buf += c;
		count -= c;
		ret= c;
	}
	return ret;
}

/* End of circula buffer methods */

static void aircable_send(struct usb_serial_port *port)
{
	int count, result;
	struct aircable_private *priv = usb_get_serial_port_data(port);
	unsigned char* buf;
	dbg("%s - port %d", __FUNCTION__, port->number);
	if (port->write_urb_busy)
		return;

	count = min(serial_buf_data_avail(priv->tx_buf), MAX_HCI_FRAMESIZE);
	if (count == 0)
		return;

	buf = kzalloc(count + HCI_HEADER_LENGTH, GFP_ATOMIC);
	if (!buf) {
		err("%s- kzalloc(%d) failed.", __FUNCTION__,
		    count + HCI_HEADER_LENGTH);
		return;
	}

	buf[0] = TX_HEADER_0;
	buf[1] = TX_HEADER_1;
	buf[2] = (unsigned char)count;
	buf[3] = (unsigned char)(count >> 8);
	serial_buf_get(priv->tx_buf,buf + HCI_HEADER_LENGTH, MAX_HCI_FRAMESIZE);

	memcpy(port->write_urb->transfer_buffer, buf,
	       count + HCI_HEADER_LENGTH);

	kfree(buf);
	port->write_urb_busy = 1;
	usb_serial_debug_data(debug, &port->dev, __FUNCTION__,
			      count + HCI_HEADER_LENGTH,
			      port->write_urb->transfer_buffer);
	port->write_urb->transfer_buffer_length = count + HCI_HEADER_LENGTH;
	port->write_urb->dev = port->serial->dev;
	result = usb_submit_urb(port->write_urb, GFP_ATOMIC);

	if (result) {
		dev_err(&port->dev,
			"%s - failed submitting write urb, error %d\n",
			__FUNCTION__, result);
		port->write_urb_busy = 0;
	}

	schedule_work(&port->work);
}

static void aircable_read(struct work_struct *work)
{
	struct aircable_private *priv =
		container_of(work, struct aircable_private, rx_work);
	struct usb_serial_port *port = priv->port;
	struct tty_struct *tty;
	unsigned char *data;
	int count;
	if (priv->rx_flags & THROTTLED){
		if (priv->rx_flags & ACTUALLY_THROTTLED)
			schedule_work(&priv->rx_work);
		return;
	}

	/* By now I will flush data to the tty in packages of no more than
	 * 64 bytes, to ensure I do not get throttled.
	 * Ask USB mailing list for better aproach.
	 */
	tty = port->tty;

	if (!tty)
		schedule_work(&priv->rx_work);

	count = min(64, serial_buf_data_avail(priv->rx_buf));

	if (count <= 0)
		return; //We have finished sending everything.

	tty_prepare_flip_string(tty, &data, count);
	if (!data){
		err("%s- kzalloc(%d) failed.", __FUNCTION__, count);
		return;
	}

	serial_buf_get(priv->rx_buf, data, count);

	tty_flip_buffer_push(tty);

	if (serial_buf_data_avail(priv->rx_buf))
		schedule_work(&priv->rx_work);

	return;
}
/* End of private methods */

static int aircable_probe(struct usb_serial *serial,
			  const struct usb_device_id *id)
{
	struct usb_host_interface *iface_desc = serial->interface->cur_altsetting;
	struct usb_endpoint_descriptor *endpoint;
	int num_bulk_out=0;
	int i;

	for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
		endpoint = &iface_desc->endpoint[i].desc;
		if (((endpoint->bEndpointAddress & 0x80) == 0x00) &&
			((endpoint->bmAttributes & 3) == 0x02)) {
			/* we found our bulk out endpoint */
			dbg("found bulk out on endpoint %d", i);
			++num_bulk_out;
		}
	}

	if (num_bulk_out == 0) {
		dbg("Invalid interface, discarding");
		return -ENODEV;
	}

	return 0;
}

static int aircable_attach (struct usb_serial *serial)
{
	struct usb_serial_port *port = serial->port[0];
	struct aircable_private *priv;

	priv = kzalloc(sizeof(struct aircable_private), GFP_KERNEL);
	if (!priv){
		err("%s- kmalloc(%Zd) failed.", __FUNCTION__,
			sizeof(struct aircable_private));
		return -ENOMEM;
	}

	/* Allocation of Circular Buffers */
	priv->tx_buf = serial_buf_alloc();
	if (priv->tx_buf == NULL) {
		kfree(priv);
		return -ENOMEM;
	}

	priv->rx_buf = serial_buf_alloc();
	if (priv->rx_buf == NULL) {
		kfree(priv->tx_buf);
		kfree(priv);
		return -ENOMEM;
	}

	priv->rx_flags &= ~(THROTTLED | ACTUALLY_THROTTLED);
	priv->port = port;
	INIT_WORK(&priv->rx_work, aircable_read);

	usb_set_serial_port_data(serial->port[0], priv);

	return 0;
}

static void aircable_shutdown(struct usb_serial *serial)
{

	struct usb_serial_port *port = serial->port[0];
	struct aircable_private *priv = usb_get_serial_port_data(port);

	dbg("%s", __FUNCTION__);

	if (priv) {
		serial_buf_free(priv->tx_buf);
		serial_buf_free(priv->rx_buf);
		usb_set_serial_port_data(port, NULL);
		kfree(priv);
	}
}

static int aircable_write_room(struct usb_serial_port *port)
{
	struct aircable_private *priv = usb_get_serial_port_data(port);
	return serial_buf_data_avail(priv->tx_buf);
}

static int aircable_write(struct usb_serial_port *port,
			  const unsigned char *source, int count)
{
	struct aircable_private *priv = usb_get_serial_port_data(port);
	int temp;

	dbg("%s - port %d, %d bytes", __FUNCTION__, port->number, count);

	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, source);

	if (!count){
		dbg("%s - write request of 0 bytes", __FUNCTION__);
		return count;
	}

	temp = serial_buf_put(priv->tx_buf, source, count);

	aircable_send(port);

	if (count > AIRCABLE_BUF_SIZE)
		count = AIRCABLE_BUF_SIZE;

	return count;

}

static void aircable_write_bulk_callback(struct urb *urb)
{
	struct usb_serial_port *port = urb->context;
	int result;

	dbg("%s - urb->status: %d", __FUNCTION__ , urb->status);

	/* This has been taken from cypress_m8.c cypress_write_int_callback */
	switch (urb->status) {
		case 0:
			/* success */
			break;
		case -ECONNRESET:
		case -ENOENT:
		case -ESHUTDOWN:
			/* this urb is terminated, clean up */
			dbg("%s - urb shutting down with status: %d",
			    __FUNCTION__, urb->status);
			port->write_urb_busy = 0;
			return;
		default:
			/* error in the urb, so we have to resubmit it */
			dbg("%s - Overflow in write", __FUNCTION__);
			dbg("%s - nonzero write bulk status received: %d",
			    __FUNCTION__, urb->status);
			port->write_urb->transfer_buffer_length = 1;
			port->write_urb->dev = port->serial->dev;
			result = usb_submit_urb(port->write_urb, GFP_KERNEL);
			if (result)
				dev_err(&urb->dev->dev,
					"%s - failed resubmitting write urb, error %d\n",
					__FUNCTION__, result);
			else
				return;
	}

	port->write_urb_busy = 0;

	aircable_send(port);
}

static void aircable_read_bulk_callback(struct urb *urb)
{
	struct usb_serial_port *port = urb->context;
	struct aircable_private *priv = usb_get_serial_port_data(port);
	struct tty_struct *tty;
	unsigned long no_packages, remaining, package_length, i;
	int result, shift = 0;
	unsigned char *temp;

	dbg("%s - port %d", __FUNCTION__, port->number);

	if (urb->status) {
		dbg("%s - urb->status = %d", __FUNCTION__, urb->status);
		if (!port->open_count) {
			dbg("%s - port is closed, exiting.", __FUNCTION__);
			return;
		}
		if (urb->status == -EPROTO) {
			dbg("%s - caught -EPROTO, resubmitting the urb",
			    __FUNCTION__);
			usb_fill_bulk_urb(port->read_urb, port->serial->dev,
					  usb_rcvbulkpipe(port->serial->dev,
					  		  port->bulk_in_endpointAddress),
					  port->read_urb->transfer_buffer,
					  port->read_urb->transfer_buffer_length,
					  aircable_read_bulk_callback, port);

			result = usb_submit_urb(urb, GFP_ATOMIC);
			if (result)
				dev_err(&urb->dev->dev,
					"%s - failed resubmitting read urb, error %d\n",
					__FUNCTION__, result);
			return;
		}
		dbg("%s - unable to handle the error, exiting.", __FUNCTION__);
		return;
	}

	usb_serial_debug_data(debug, &port->dev, __FUNCTION__,
				urb->actual_length,urb->transfer_buffer);

	tty = port->tty;
	if (tty && urb->actual_length) {
		if (urb->actual_length <= 2) {
			/* This is an incomplete package */
			serial_buf_put(priv->rx_buf, urb->transfer_buffer,
				       urb->actual_length);
		} else {
			temp = urb->transfer_buffer;
			if (temp[0] == RX_HEADER_0)
				shift = HCI_HEADER_LENGTH;

			remaining = urb->actual_length;
			no_packages = urb->actual_length / (HCI_COMPLETE_FRAME);

			if (urb->actual_length % HCI_COMPLETE_FRAME != 0)
				no_packages+=1;

			for (i = 0; i < no_packages ;i++) {
				if (remaining > (HCI_COMPLETE_FRAME))
					package_length = HCI_COMPLETE_FRAME;
				else
					package_length = remaining;
				remaining -= package_length;

				serial_buf_put(priv->rx_buf,
					urb->transfer_buffer + shift +
					(HCI_COMPLETE_FRAME) * (i),
					package_length - shift);
			}
		}
		aircable_read(&priv->rx_work);
	}

	/* Schedule the next read _if_ we are still open */
	if (port->open_count) {
		usb_fill_bulk_urb(port->read_urb, port->serial->dev,
				  usb_rcvbulkpipe(port->serial->dev,
				  		  port->bulk_in_endpointAddress),
				  port->read_urb->transfer_buffer,
				  port->read_urb->transfer_buffer_length,
				  aircable_read_bulk_callback, port);

		result = usb_submit_urb(urb, GFP_ATOMIC);
		if (result)
			dev_err(&urb->dev->dev,
				"%s - failed resubmitting read urb, error %d\n",
				__FUNCTION__, result);
	}

	return;
}

/* Based on ftdi_sio.c throttle */
static void aircable_throttle(struct usb_serial_port *port)
{
	struct aircable_private *priv = usb_get_serial_port_data(port);
	unsigned long flags;

	dbg("%s - port %d", __FUNCTION__, port->number);

	spin_lock_irqsave(&priv->rx_lock, flags);
	priv->rx_flags |= THROTTLED;
	spin_unlock_irqrestore(&priv->rx_lock, flags);
}

/* Based on ftdi_sio.c unthrottle */
static void aircable_unthrottle(struct usb_serial_port *port)
{
	struct aircable_private *priv = usb_get_serial_port_data(port);
	int actually_throttled;
	unsigned long flags;

	dbg("%s - port %d", __FUNCTION__, port->number);

	spin_lock_irqsave(&priv->rx_lock, flags);
	actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
	priv->rx_flags &= ~(THROTTLED | ACTUALLY_THROTTLED);
	spin_unlock_irqrestore(&priv->rx_lock, flags);

	if (actually_throttled)
		schedule_work(&priv->rx_work);
}

static struct usb_serial_driver aircable_device = {
	.description =		"aircable",
	.id_table = 		id_table,
	.num_ports =		1,
	.attach =		aircable_attach,
	.probe =		aircable_probe,
	.shutdown =		aircable_shutdown,
	.write =		aircable_write,
	.write_room =		aircable_write_room,
	.write_bulk_callback =	aircable_write_bulk_callback,
	.read_bulk_callback =	aircable_read_bulk_callback,
	.throttle =		aircable_throttle,
	.unthrottle =		aircable_unthrottle,
};

static struct usb_driver aircable_driver = {
	.name =		"aircable",
	.probe =	usb_serial_probe,
	.disconnect =	usb_serial_disconnect,
	.id_table =	id_table,
};

static int __init aircable_init (void)
{
	int retval;
	retval = usb_serial_register(&aircable_device);
	if (retval)
		goto failed_serial_register;
	retval = usb_register(&aircable_driver);
	if (retval)
		goto failed_usb_register;
	return 0;

failed_serial_register:
	usb_serial_deregister(&aircable_device);
failed_usb_register:
	return retval;
}

static void __exit aircable_exit (void)
{
	usb_deregister(&aircable_driver);
	usb_serial_deregister(&aircable_device);
}

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_VERSION(DRIVER_VERSION);
MODULE_LICENSE("GPL");

module_init(aircable_init);
module_exit(aircable_exit);

module_param(debug, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Debug enabled or not");
Commit	Line	Data
3fe70ba2 MFN	1	/*
	2	* AIRcable USB Bluetooth Dongle Driver.
	3	*
	4	* Copyright (C) 2006 Manuel Francisco Naranjo (naranjo.manuel@gmail.com)
	5	* This program is free software; you can redistribute it and/or modify it under
	6	* the terms of the GNU General Public License version 2 as published by the
	7	* Free Software Foundation.
	8	*
	9	* The device works as an standard CDC device, it has 2 interfaces, the first
	10	* one is for firmware access and the second is the serial one.
	11	* The protocol is very simply, there are two posibilities reading or writing.
	12	* When writting the first urb must have a Header that starts with 0x20 0x29 the
	13	* next two bytes must say how much data will be sended.
	14	* When reading the process is almost equal except that the header starts with
	15	* 0x00 0x20.
	16	*
	17	* The device simply need some stuff to understand data comming from the usb
	18	* buffer: The First and Second byte is used for a Header, the Third and Fourth
	19	* tells the device the amount of information the package holds.
	20	* Packages are 60 bytes long Header Stuff.
	21	* When writting to the device the first two bytes of the header are 0x20 0x29
	22	* When reading the bytes are 0x00 0x20, or 0x00 0x10, there is an strange
	23	* situation, when too much data arrives to the device because it sends the data
	24	* but with out the header. I will use a simply hack to override this situation,
	25	* if there is data coming that does not contain any header, then that is data
	26	* that must go directly to the tty, as there is no documentation about if there
	27	* is any other control code, I will simply check for the first
	28	* one.
	29	*
	30	* The driver registers himself with the USB-serial core and the USB Core. I had
	31	* to implement a probe function agains USB-serial, because other way, the
	32	* driver was attaching himself to both interfaces. I have tryed with different
	33	* configurations of usb_serial_driver with out exit, only the probe function
	34	* could handle this correctly.
	35	*
	36	* I have taken some info from a Greg Kroah-Hartman article:
	37	* http://www.linuxjournal.com/article/6573
	38	* And from Linux Device Driver Kit CD, which is a great work, the authors taken
	39	* the work to recompile lots of information an knowladge in drivers development
	40	* and made it all avaible inside a cd.
	41	* URL: http://kernel.org/pub/linux/kernel/people/gregkh/ddk/
	42	*
	43	*/
	44
	45	#include <linux/tty.h>
	46	#include <linux/tty_flip.h>
	47	#include <linux/circ_buf.h>
	48	#include <linux/usb.h>
	49	#include <linux/usb/serial.h>
	50
	51	static int debug;
	52
	53	/* Vendor and Product ID */
	54	#define AIRCABLE_VID 0x16CA
	55	#define AIRCABLE_USB_PID 0x1502
	56
	57	/* write buffer size defines */
	58	#define AIRCABLE_BUF_SIZE 2048
	59
	60	/* Protocol Stuff */
	61	#define HCI_HEADER_LENGTH 0x4
	62	#define TX_HEADER_0 0x20
	63	#define TX_HEADER_1 0x29
	64	#define RX_HEADER_0 0x00
65	#define RX_HEADER_1 0x20
66	#define MAX_HCI_FRAMESIZE 60
67	#define HCI_COMPLETE_FRAME 64
68
69	/* rx_flags */
70	#define THROTTLED 0x01
71	#define ACTUALLY_THROTTLED 0x02
72
73	/*
74	* Version Information
75	*/
76	#define DRIVER_VERSION "v1.0b2"
77	#define DRIVER_AUTHOR "Naranjo, Manuel Francisco <naranjo.manuel@gmail.com>"
78	#define DRIVER_DESC "AIRcable USB Driver"
79
80	/* ID table that will be registered with USB core */
81	static struct usb_device_id id_table [] = {
82	{ USB_DEVICE(AIRCABLE_VID, AIRCABLE_USB_PID) },
83	{ },
84	};
85	MODULE_DEVICE_TABLE(usb, id_table);
86
87
88	/* Internal Structure */
89	struct aircable_private {
90	spinlock_t rx_lock; /* spinlock for the receive lines */
91	struct circ_buf tx_buf; / write buffer */
92	struct circ_buf rx_buf; / read buffer */
93	int rx_flags; /* for throttilng */
94	struct work_struct rx_work; /* work cue for the receiving line */
c4028958	95	struct usb_serial_port port; / USB port with which associated */
3fe70ba2 MFN	96	};
	97
	98	/* Private methods */
	99
	100	/* Circular Buffer Methods, code from ti_usb_3410_5052 used */
	101	/*
	102	* serial_buf_clear
	103	*
	104	* Clear out all data in the circular buffer.
	105	*/
	106	static void serial_buf_clear(struct circ_buf *cb)
	107	{
	108	cb->head = cb->tail = 0;
	109	}
	110
	111	/*
	112	* serial_buf_alloc
	113	*
	114	* Allocate a circular buffer and all associated memory.
	115	*/
	116	static struct circ_buf *serial_buf_alloc(void)
	117	{
	118	struct circ_buf *cb;
	119	cb = kmalloc(sizeof(struct circ_buf), GFP_KERNEL);
	120	if (cb == NULL)
	121	return NULL;
	122	cb->buf = kmalloc(AIRCABLE_BUF_SIZE, GFP_KERNEL);
	123	if (cb->buf == NULL) {
	124	kfree(cb);
	125	return NULL;
	126	}
	127	serial_buf_clear(cb);
	128	return cb;
	129	}
	130
	131	/*
	132	* serial_buf_free
	133	*
	134	* Free the buffer and all associated memory.
	135	*/
	136	static void serial_buf_free(struct circ_buf *cb)
	137	{
	138	kfree(cb->buf);
	139	kfree(cb);
	140	}
	141
	142	/*
	143	* serial_buf_data_avail
	144	*
	145	* Return the number of bytes of data available in the circular
	146	* buffer.
	147	*/
	148	static int serial_buf_data_avail(struct circ_buf *cb)
	149	{
	150	return CIRC_CNT(cb->head,cb->tail,AIRCABLE_BUF_SIZE);
	151	}
	152
	153	/*
	154	* serial_buf_put
	155	*
	156	* Copy data data from a user buffer and put it into the circular buffer.
	157	* Restrict to the amount of space available.
	158	*
	159	* Return the number of bytes copied.
160	*/
161	static int serial_buf_put(struct circ_buf cb, const char buf, int count)
162	{
163	int c, ret = 0;
164	while (1) {
165	c = CIRC_SPACE_TO_END(cb->head, cb->tail, AIRCABLE_BUF_SIZE);
166	if (count < c)
167	c = count;
168	if (c <= 0)
169	break;
170	memcpy(cb->buf + cb->head, buf, c);
171	cb->head = (cb->head + c) & (AIRCABLE_BUF_SIZE-1);
172	buf += c;
173	count -= c;
174	ret= c;
175	}
176	return ret;
177	}
178
179	/*
180	* serial_buf_get
181	*
182	* Get data from the circular buffer and copy to the given buffer.
183	* Restrict to the amount of data available.
184	*
185	* Return the number of bytes copied.
186	*/
187	static int serial_buf_get(struct circ_buf cb, char buf, int count)
188	{
189	int c, ret = 0;
190	while (1) {
191	c = CIRC_CNT_TO_END(cb->head, cb->tail, AIRCABLE_BUF_SIZE);
192	if (count < c)
193	c = count;
194	if (c <= 0)
195	break;
196	memcpy(buf, cb->buf + cb->tail, c);
197	cb->tail = (cb->tail + c) & (AIRCABLE_BUF_SIZE-1);
198	buf += c;
199	count -= c;
200	ret= c;
201	}
202	return ret;
203	}
204
205	/* End of circula buffer methods */
206
207	static void aircable_send(struct usb_serial_port *port)
208	{
209	int count, result;
210	struct aircable_private *priv = usb_get_serial_port_data(port);
211	unsigned char* buf;
212	dbg("%s - port %d", __FUNCTION__, port->number);
213	if (port->write_urb_busy)
214	return;
215
216	count = min(serial_buf_data_avail(priv->tx_buf), MAX_HCI_FRAMESIZE);
217	if (count == 0)
218	return;
219
220	buf = kzalloc(count + HCI_HEADER_LENGTH, GFP_ATOMIC);
221	if (!buf) {
8ac283ad	222	err("%s- kzalloc(%d) failed.", __FUNCTION__,
3fe70ba2 MFN	223	count + HCI_HEADER_LENGTH);
	224	return;
	225	}
	226
	227	buf[0] = TX_HEADER_0;
	228	buf[1] = TX_HEADER_1;
	229	buf[2] = (unsigned char)count;
	230	buf[3] = (unsigned char)(count >> 8);
	231	serial_buf_get(priv->tx_buf,buf + HCI_HEADER_LENGTH, MAX_HCI_FRAMESIZE);
	232
	233	memcpy(port->write_urb->transfer_buffer, buf,
	234	count + HCI_HEADER_LENGTH);
	235
	236	kfree(buf);
	237	port->write_urb_busy = 1;
	238	usb_serial_debug_data(debug, &port->dev, __FUNCTION__,
	239	count + HCI_HEADER_LENGTH,
	240	port->write_urb->transfer_buffer);
	241	port->write_urb->transfer_buffer_length = count + HCI_HEADER_LENGTH;
	242	port->write_urb->dev = port->serial->dev;
	243	result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
	244
	245	if (result) {
	246	dev_err(&port->dev,
	247	"%s - failed submitting write urb, error %d\n",
	248	__FUNCTION__, result);
	249	port->write_urb_busy = 0;
	250	}
	251
	252	schedule_work(&port->work);
	253	}
	254
c4028958	255	static void aircable_read(struct work_struct *work)
3fe70ba2	256	{
c4028958 DH	257	struct aircable_private *priv =
	258	container_of(work, struct aircable_private, rx_work);
	259	struct usb_serial_port *port = priv->port;
3fe70ba2 MFN	260	struct tty_struct *tty;
	261	unsigned char *data;
	262	int count;
	263	if (priv->rx_flags & THROTTLED){
	264	if (priv->rx_flags & ACTUALLY_THROTTLED)
	265	schedule_work(&priv->rx_work);
	266	return;
	267	}
	268
	269	/* By now I will flush data to the tty in packages of no more than
	270	* 64 bytes, to ensure I do not get throttled.
	271	* Ask USB mailing list for better aproach.
	272	*/
	273	tty = port->tty;
	274
	275	if (!tty)
	276	schedule_work(&priv->rx_work);
	277
	278	count = min(64, serial_buf_data_avail(priv->rx_buf));
	279
	280	if (count <= 0)
	281	return; //We have finished sending everything.
	282
	283	tty_prepare_flip_string(tty, &data, count);
	284	if (!data){
8ac283ad	285	err("%s- kzalloc(%d) failed.", __FUNCTION__, count);
3fe70ba2 MFN	286	return;
	287	}
	288
	289	serial_buf_get(priv->rx_buf, data, count);
	290
	291	tty_flip_buffer_push(tty);
	292
	293	if (serial_buf_data_avail(priv->rx_buf))
	294	schedule_work(&priv->rx_work);
	295
	296	return;
	297	}
	298	/* End of private methods */
	299
	300	static int aircable_probe(struct usb_serial *serial,
	301	const struct usb_device_id *id)
	302	{
	303	struct usb_host_interface *iface_desc = serial->interface->cur_altsetting;
	304	struct usb_endpoint_descriptor *endpoint;
	305	int num_bulk_out=0;
	306	int i;
	307
	308	for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
	309	endpoint = &iface_desc->endpoint[i].desc;
	310	if (((endpoint->bEndpointAddress & 0x80) == 0x00) &&
	311	((endpoint->bmAttributes & 3) == 0x02)) {
	312	/* we found our bulk out endpoint */
	313	dbg("found bulk out on endpoint %d", i);
	314	++num_bulk_out;
	315	}
	316	}
	317
	318	if (num_bulk_out == 0) {
	319	dbg("Invalid interface, discarding");
	320	return -ENODEV;
	321	}
	322
	323	return 0;
	324	}
	325
	326	static int aircable_attach (struct usb_serial *serial)
	327	{
	328	struct usb_serial_port *port = serial->port[0];
	329	struct aircable_private *priv;
	330
	331	priv = kzalloc(sizeof(struct aircable_private), GFP_KERNEL);
	332	if (!priv){
	333	err("%s- kmalloc(%Zd) failed.", __FUNCTION__,
	334	sizeof(struct aircable_private));
	335	return -ENOMEM;
	336	}
	337
	338	/* Allocation of Circular Buffers */
	339	priv->tx_buf = serial_buf_alloc();
	340	if (priv->tx_buf == NULL) {
	341	kfree(priv);
	342	return -ENOMEM;
	343	}
	344
	345	priv->rx_buf = serial_buf_alloc();
	346	if (priv->rx_buf == NULL) {
	347	kfree(priv->tx_buf);
	348	kfree(priv);
	349	return -ENOMEM;
350	}
351
352	priv->rx_flags &= ~(THROTTLED \| ACTUALLY_THROTTLED);
c4028958 DH	353	priv->port = port;
c4028958 DH	354	INIT_WORK(&priv->rx_work, aircable_read);
3fe70ba2 MFN	355
	356	usb_set_serial_port_data(serial->port[0], priv);
	357
	358	return 0;
	359	}
	360
	361	static void aircable_shutdown(struct usb_serial *serial)
	362	{
	363
	364	struct usb_serial_port *port = serial->port[0];
	365	struct aircable_private *priv = usb_get_serial_port_data(port);
	366
	367	dbg("%s", __FUNCTION__);
	368
	369	if (priv) {
	370	serial_buf_free(priv->tx_buf);
	371	serial_buf_free(priv->rx_buf);
	372	usb_set_serial_port_data(port, NULL);
	373	kfree(priv);
	374	}
	375	}
	376
	377	static int aircable_write_room(struct usb_serial_port *port)
	378	{
	379	struct aircable_private *priv = usb_get_serial_port_data(port);
	380	return serial_buf_data_avail(priv->tx_buf);
	381	}
	382
	383	static int aircable_write(struct usb_serial_port *port,
	384	const unsigned char *source, int count)
	385	{
	386	struct aircable_private *priv = usb_get_serial_port_data(port);
	387	int temp;
	388
	389	dbg("%s - port %d, %d bytes", __FUNCTION__, port->number, count);
	390
	391	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, source);
	392
	393	if (!count){
	394	dbg("%s - write request of 0 bytes", __FUNCTION__);
	395	return count;
	396	}
	397
	398	temp = serial_buf_put(priv->tx_buf, source, count);
	399
	400	aircable_send(port);
	401
	402	if (count > AIRCABLE_BUF_SIZE)
	403	count = AIRCABLE_BUF_SIZE;
	404
	405	return count;
	406
	407	}
	408
7d12e780	409	static void aircable_write_bulk_callback(struct urb *urb)
3fe70ba2 MFN	410	{
	411	struct usb_serial_port *port = urb->context;
	412	int result;
	413
	414	dbg("%s - urb->status: %d", __FUNCTION__ , urb->status);
	415
	416	/* This has been taken from cypress_m8.c cypress_write_int_callback */
	417	switch (urb->status) {
	418	case 0:
	419	/* success */
	420	break;
	421	case -ECONNRESET:
	422	case -ENOENT:
	423	case -ESHUTDOWN:
	424	/* this urb is terminated, clean up */
	425	dbg("%s - urb shutting down with status: %d",
	426	__FUNCTION__, urb->status);
	427	port->write_urb_busy = 0;
	428	return;
	429	default:
	430	/* error in the urb, so we have to resubmit it */
	431	dbg("%s - Overflow in write", __FUNCTION__);
	432	dbg("%s - nonzero write bulk status received: %d",
	433	__FUNCTION__, urb->status);
	434	port->write_urb->transfer_buffer_length = 1;
	435	port->write_urb->dev = port->serial->dev;
	436	result = usb_submit_urb(port->write_urb, GFP_KERNEL);
	437	if (result)
	438	dev_err(&urb->dev->dev,
	439	"%s - failed resubmitting write urb, error %d\n",
	440	__FUNCTION__, result);
	441	else
	442	return;
	443	}
	444
	445	port->write_urb_busy = 0;
	446
	447	aircable_send(port);
	448	}
	449
7d12e780	450	static void aircable_read_bulk_callback(struct urb *urb)
3fe70ba2 MFN	451	{
	452	struct usb_serial_port *port = urb->context;
	453	struct aircable_private *priv = usb_get_serial_port_data(port);
	454	struct tty_struct *tty;
	455	unsigned long no_packages, remaining, package_length, i;
	456	int result, shift = 0;
	457	unsigned char *temp;
	458
	459	dbg("%s - port %d", __FUNCTION__, port->number);
	460
	461	if (urb->status) {
	462	dbg("%s - urb->status = %d", __FUNCTION__, urb->status);
	463	if (!port->open_count) {
	464	dbg("%s - port is closed, exiting.", __FUNCTION__);
	465	return;
	466	}
	467	if (urb->status == -EPROTO) {
	468	dbg("%s - caught -EPROTO, resubmitting the urb",
	469	__FUNCTION__);
	470	usb_fill_bulk_urb(port->read_urb, port->serial->dev,
	471	usb_rcvbulkpipe(port->serial->dev,
	472	port->bulk_in_endpointAddress),
	473	port->read_urb->transfer_buffer,
	474	port->read_urb->transfer_buffer_length,
	475	aircable_read_bulk_callback, port);
	476
	477	result = usb_submit_urb(urb, GFP_ATOMIC);
	478	if (result)
	479	dev_err(&urb->dev->dev,
	480	"%s - failed resubmitting read urb, error %d\n",
	481	__FUNCTION__, result);
	482	return;
	483	}
	484	dbg("%s - unable to handle the error, exiting.", __FUNCTION__);
	485	return;
	486	}
	487
	488	usb_serial_debug_data(debug, &port->dev, __FUNCTION__,
	489	urb->actual_length,urb->transfer_buffer);
	490
	491	tty = port->tty;
	492	if (tty && urb->actual_length) {
	493	if (urb->actual_length <= 2) {
	494	/* This is an incomplete package */
	495	serial_buf_put(priv->rx_buf, urb->transfer_buffer,
	496	urb->actual_length);
	497	} else {
	498	temp = urb->transfer_buffer;
	499	if (temp[0] == RX_HEADER_0)
	500	shift = HCI_HEADER_LENGTH;
	501
	502	remaining = urb->actual_length;
	503	no_packages = urb->actual_length / (HCI_COMPLETE_FRAME);
	504
	505	if (urb->actual_length % HCI_COMPLETE_FRAME != 0)
	506	no_packages+=1;
	507
	508	for (i = 0; i < no_packages ;i++) {
	509	if (remaining > (HCI_COMPLETE_FRAME))
	510	package_length = HCI_COMPLETE_FRAME;
	511	else
	512	package_length = remaining;
	513	remaining -= package_length;
	514
515	serial_buf_put(priv->rx_buf,
516	urb->transfer_buffer + shift +
517	(HCI_COMPLETE_FRAME) * (i),
518	package_length - shift);
519	}
520	}
c4028958	521	aircable_read(&priv->rx_work);
3fe70ba2 MFN	522	}
	523
	524	/* Schedule the next read _if_ we are still open */
	525	if (port->open_count) {
	526	usb_fill_bulk_urb(port->read_urb, port->serial->dev,
	527	usb_rcvbulkpipe(port->serial->dev,
	528	port->bulk_in_endpointAddress),
	529	port->read_urb->transfer_buffer,
	530	port->read_urb->transfer_buffer_length,
	531	aircable_read_bulk_callback, port);
	532
	533	result = usb_submit_urb(urb, GFP_ATOMIC);
	534	if (result)
	535	dev_err(&urb->dev->dev,
	536	"%s - failed resubmitting read urb, error %d\n",
	537	__FUNCTION__, result);
	538	}
	539
	540	return;
	541	}
	542
	543	/* Based on ftdi_sio.c throttle */
	544	static void aircable_throttle(struct usb_serial_port *port)
	545	{
	546	struct aircable_private *priv = usb_get_serial_port_data(port);
	547	unsigned long flags;
	548
	549	dbg("%s - port %d", __FUNCTION__, port->number);
	550
	551	spin_lock_irqsave(&priv->rx_lock, flags);
	552	priv->rx_flags \|= THROTTLED;
	553	spin_unlock_irqrestore(&priv->rx_lock, flags);
	554	}
	555
	556	/* Based on ftdi_sio.c unthrottle */
	557	static void aircable_unthrottle(struct usb_serial_port *port)
	558	{
	559	struct aircable_private *priv = usb_get_serial_port_data(port);
	560	int actually_throttled;
	561	unsigned long flags;
	562
	563	dbg("%s - port %d", __FUNCTION__, port->number);
	564
	565	spin_lock_irqsave(&priv->rx_lock, flags);
	566	actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
	567	priv->rx_flags &= ~(THROTTLED \| ACTUALLY_THROTTLED);
	568	spin_unlock_irqrestore(&priv->rx_lock, flags);
	569
	570	if (actually_throttled)
	571	schedule_work(&priv->rx_work);
	572	}
	573
	574	static struct usb_serial_driver aircable_device = {
	575	.description = "aircable",
	576	.id_table = id_table,
	577	.num_ports = 1,
	578	.attach = aircable_attach,
	579	.probe = aircable_probe,
	580	.shutdown = aircable_shutdown,
	581	.write = aircable_write,
	582	.write_room = aircable_write_room,
	583	.write_bulk_callback = aircable_write_bulk_callback,
	584	.read_bulk_callback = aircable_read_bulk_callback,
	585	.throttle = aircable_throttle,
586	.unthrottle = aircable_unthrottle,
587	};
588
589	static struct usb_driver aircable_driver = {
590	.name = "aircable",
591	.probe = usb_serial_probe,
592	.disconnect = usb_serial_disconnect,
593	.id_table = id_table,
594	};
595
596	static int __init aircable_init (void)
597	{
598	int retval;
599	retval = usb_serial_register(&aircable_device);
600	if (retval)
601	goto failed_serial_register;
602	retval = usb_register(&aircable_driver);
603	if (retval)
604	goto failed_usb_register;
605	return 0;
606
607	failed_serial_register:
608	usb_serial_deregister(&aircable_device);
609	failed_usb_register:
610	return retval;
611	}
612
613	static void __exit aircable_exit (void)
614	{
615	usb_deregister(&aircable_driver);
616	usb_serial_deregister(&aircable_device);
617	}
618
619	MODULE_AUTHOR(DRIVER_AUTHOR);
620	MODULE_DESCRIPTION(DRIVER_DESC);
621	MODULE_VERSION(DRIVER_VERSION);
622	MODULE_LICENSE("GPL");
623
624	module_init(aircable_init);
625	module_exit(aircable_exit);
626
627	module_param(debug, bool, S_IRUGO \| S_IWUSR);
628	MODULE_PARM_DESC(debug, "Debug enabled or not");