diff options
Diffstat (limited to 'drivers/usb/serial/aircable.c')
| -rw-r--r-- | drivers/usb/serial/aircable.c | 625 |
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 00000000000..2ccd9ded52a --- /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(%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(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(%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); + 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"); |