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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 | // 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"); |