Add AIRcable USB Bluetooth Dongle Driver

Add driver for AIRcable USB Bluetooth dongle.

Signed-off-by: Naranjo, Manuel Francisco <naranjo.manuel@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 625 insertions, 0 deletions

diff --git a/drivers/usb/serial/aircable.c b/drivers/usb/serial/aircable.c
new file mode 100644
index 000000000000..8aaf7db93992
--- /dev/null
+++ b/drivers/usb/serial/aircable.c
@@ -0,0 +1,625 @@
+/*
+ * 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 */
+};
+
+/* 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(%Zd) 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(void *params)
+{
+	struct usb_serial_port *port = params;
+	struct aircable_private *priv = usb_get_serial_port_data(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(%Zd) 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);
+	INIT_WORK(&priv->rx_work, aircable_read, port);
+
+	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 pt_regs *regs)
+{
+	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 pt_regs *regs)
+{
+	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(port);
+	}
+
+	/* 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");