diff options
Diffstat (limited to 'drivers/usb/serial/aircable.c')
| -rw-r--r-- | drivers/usb/serial/aircable.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/drivers/usb/serial/aircable.c b/drivers/usb/serial/aircable.c new file mode 100644 index 000000000..a1df686c3 --- /dev/null +++ b/drivers/usb/serial/aircable.c @@ -0,0 +1,161 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * AIRcable USB Bluetooth Dongle Driver. + * + * Copyright (C) 2010 Johan Hovold <jhovold@gmail.com> + * Copyright (C) 2006 Manuel Francisco Naranjo (naranjo.manuel@gmail.com) + * + * 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 possibilities reading or writing. + * When writing the first urb must have a Header that starts with 0x20 0x29 the + * next two bytes must say how much data will be sent. + * When reading the process is almost equal except that the header starts with + * 0x00 0x20. + * + * The device simply need some stuff to understand data coming 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 writing 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. + * + * 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 knowledge in drivers development + * and made it all available inside a cd. + * URL: http://kernel.org/pub/linux/kernel/people/gregkh/ddk/ + * + */ + +#include <asm/unaligned.h> +#include <linux/tty.h> +#include <linux/slab.h> +#include <linux/module.h> +#include <linux/tty_flip.h> +#include <linux/usb.h> +#include <linux/usb/serial.h> + +/* Vendor and Product ID */ +#define AIRCABLE_VID 0x16CA +#define AIRCABLE_USB_PID 0x1502 + +/* 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 HCI_COMPLETE_FRAME 64 + +/* rx_flags */ +#define THROTTLED 0x01 +#define ACTUALLY_THROTTLED 0x02 + +#define DRIVER_AUTHOR "Naranjo, Manuel Francisco <naranjo.manuel@gmail.com>, Johan Hovold <jhovold@gmail.com>" +#define DRIVER_DESC "AIRcable USB Driver" + +/* ID table that will be registered with USB core */ +static const struct usb_device_id id_table[] = { + { USB_DEVICE(AIRCABLE_VID, AIRCABLE_USB_PID) }, + { }, +}; +MODULE_DEVICE_TABLE(usb, id_table); + +static int aircable_prepare_write_buffer(struct usb_serial_port *port, + void *dest, size_t size) +{ + int count; + unsigned char *buf = dest; + + count = kfifo_out_locked(&port->write_fifo, buf + HCI_HEADER_LENGTH, + size - HCI_HEADER_LENGTH, &port->lock); + buf[0] = TX_HEADER_0; + buf[1] = TX_HEADER_1; + put_unaligned_le16(count, &buf[2]); + + return count + HCI_HEADER_LENGTH; +} + +static int aircable_calc_num_ports(struct usb_serial *serial, + struct usb_serial_endpoints *epds) +{ + /* Ignore the first interface, which has no bulk endpoints. */ + if (epds->num_bulk_out == 0) { + dev_dbg(&serial->interface->dev, + "ignoring interface with no bulk-out endpoints\n"); + return -ENODEV; + } + + return 1; +} + +static int aircable_process_packet(struct usb_serial_port *port, + int has_headers, char *packet, int len) +{ + if (has_headers) { + len -= HCI_HEADER_LENGTH; + packet += HCI_HEADER_LENGTH; + } + if (len <= 0) { + dev_dbg(&port->dev, "%s - malformed packet\n", __func__); + return 0; + } + + tty_insert_flip_string(&port->port, packet, len); + + return len; +} + +static void aircable_process_read_urb(struct urb *urb) +{ + struct usb_serial_port *port = urb->context; + char *data = urb->transfer_buffer; + int has_headers; + int count; + int len; + int i; + + has_headers = (urb->actual_length > 2 && data[0] == RX_HEADER_0); + + count = 0; + for (i = 0; i < urb->actual_length; i += HCI_COMPLETE_FRAME) { + len = min_t(int, urb->actual_length - i, HCI_COMPLETE_FRAME); + count += aircable_process_packet(port, has_headers, + &data[i], len); + } + + if (count) + tty_flip_buffer_push(&port->port); +} + +static struct usb_serial_driver aircable_device = { + .driver = { + .owner = THIS_MODULE, + .name = "aircable", + }, + .id_table = id_table, + .bulk_out_size = HCI_COMPLETE_FRAME, + .calc_num_ports = aircable_calc_num_ports, + .process_read_urb = aircable_process_read_urb, + .prepare_write_buffer = aircable_prepare_write_buffer, + .throttle = usb_serial_generic_throttle, + .unthrottle = usb_serial_generic_unthrottle, +}; + +static struct usb_serial_driver * const serial_drivers[] = { + &aircable_device, NULL +}; + +module_usb_serial_driver(serial_drivers, id_table); + +MODULE_AUTHOR(DRIVER_AUTHOR); +MODULE_DESCRIPTION(DRIVER_DESC); +MODULE_LICENSE("GPL v2"); |