/* * AIRcable USB Bluetooth Dongle Driver. * * Copyright (C) 2010 Johan Hovold <jhovold@gmail.com> * 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 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. * * The driver registers himself with the USB-serial core and the USB Core. I had * to implement a probe function against USB-serial, because other way, the * driver was attaching himself to both interfaces. I have tried 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 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_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 (usb_endpoint_is_bulk_out(endpoint)) { dev_dbg(&serial->dev->dev, "found bulk out on endpoint %d\n", i); ++num_bulk_out; } } if (num_bulk_out == 0) { dev_dbg(&serial->dev->dev, "Invalid interface, discarding\n"); return -ENODEV; } return 0; } 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 = (char *)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, .num_ports = 1, .bulk_out_size = HCI_COMPLETE_FRAME, .probe = aircable_probe, .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");