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");