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![Johan Hovold](/assets/img/avatar_default.png)
Drop redundant URB transfer-buffer casts. Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Johan Hovold <johan@kernel.org>
161 lines
4.9 KiB
C
161 lines
4.9 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* AIRcable USB Bluetooth Dongle Driver.
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*
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* Copyright (C) 2010 Johan Hovold <jhovold@gmail.com>
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* Copyright (C) 2006 Manuel Francisco Naranjo (naranjo.manuel@gmail.com)
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*
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* The device works as an standard CDC device, it has 2 interfaces, the first
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* one is for firmware access and the second is the serial one.
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* The protocol is very simply, there are two possibilities reading or writing.
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* When writing the first urb must have a Header that starts with 0x20 0x29 the
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* next two bytes must say how much data will be sent.
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* When reading the process is almost equal except that the header starts with
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* 0x00 0x20.
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*
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* The device simply need some stuff to understand data coming from the usb
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* buffer: The First and Second byte is used for a Header, the Third and Fourth
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* tells the device the amount of information the package holds.
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* Packages are 60 bytes long Header Stuff.
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* When writing to the device the first two bytes of the header are 0x20 0x29
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* When reading the bytes are 0x00 0x20, or 0x00 0x10, there is an strange
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* situation, when too much data arrives to the device because it sends the data
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* but with out the header. I will use a simply hack to override this situation,
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* if there is data coming that does not contain any header, then that is data
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* that must go directly to the tty, as there is no documentation about if there
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* is any other control code, I will simply check for the first
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* one.
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*
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* I have taken some info from a Greg Kroah-Hartman article:
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* http://www.linuxjournal.com/article/6573
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* And from Linux Device Driver Kit CD, which is a great work, the authors taken
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* the work to recompile lots of information an knowledge in drivers development
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* and made it all available inside a cd.
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* URL: http://kernel.org/pub/linux/kernel/people/gregkh/ddk/
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*
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*/
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#include <asm/unaligned.h>
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#include <linux/tty.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <linux/tty_flip.h>
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#include <linux/usb.h>
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#include <linux/usb/serial.h>
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/* Vendor and Product ID */
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#define AIRCABLE_VID 0x16CA
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#define AIRCABLE_USB_PID 0x1502
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/* Protocol Stuff */
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#define HCI_HEADER_LENGTH 0x4
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#define TX_HEADER_0 0x20
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#define TX_HEADER_1 0x29
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#define RX_HEADER_0 0x00
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#define RX_HEADER_1 0x20
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#define HCI_COMPLETE_FRAME 64
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/* rx_flags */
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#define THROTTLED 0x01
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#define ACTUALLY_THROTTLED 0x02
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#define DRIVER_AUTHOR "Naranjo, Manuel Francisco <naranjo.manuel@gmail.com>, Johan Hovold <jhovold@gmail.com>"
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#define DRIVER_DESC "AIRcable USB Driver"
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/* ID table that will be registered with USB core */
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static const struct usb_device_id id_table[] = {
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{ USB_DEVICE(AIRCABLE_VID, AIRCABLE_USB_PID) },
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{ },
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};
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MODULE_DEVICE_TABLE(usb, id_table);
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static int aircable_prepare_write_buffer(struct usb_serial_port *port,
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void *dest, size_t size)
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{
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int count;
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unsigned char *buf = dest;
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count = kfifo_out_locked(&port->write_fifo, buf + HCI_HEADER_LENGTH,
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size - HCI_HEADER_LENGTH, &port->lock);
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buf[0] = TX_HEADER_0;
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buf[1] = TX_HEADER_1;
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put_unaligned_le16(count, &buf[2]);
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return count + HCI_HEADER_LENGTH;
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}
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static int aircable_calc_num_ports(struct usb_serial *serial,
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struct usb_serial_endpoints *epds)
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{
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/* Ignore the first interface, which has no bulk endpoints. */
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if (epds->num_bulk_out == 0) {
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dev_dbg(&serial->interface->dev,
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"ignoring interface with no bulk-out endpoints\n");
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return -ENODEV;
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}
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return 1;
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}
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static int aircable_process_packet(struct usb_serial_port *port,
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int has_headers, char *packet, int len)
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{
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if (has_headers) {
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len -= HCI_HEADER_LENGTH;
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packet += HCI_HEADER_LENGTH;
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}
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if (len <= 0) {
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dev_dbg(&port->dev, "%s - malformed packet\n", __func__);
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return 0;
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}
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tty_insert_flip_string(&port->port, packet, len);
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return len;
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}
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static void aircable_process_read_urb(struct urb *urb)
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{
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struct usb_serial_port *port = urb->context;
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char *data = urb->transfer_buffer;
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int has_headers;
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int count;
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int len;
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int i;
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has_headers = (urb->actual_length > 2 && data[0] == RX_HEADER_0);
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count = 0;
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for (i = 0; i < urb->actual_length; i += HCI_COMPLETE_FRAME) {
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len = min_t(int, urb->actual_length - i, HCI_COMPLETE_FRAME);
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count += aircable_process_packet(port, has_headers,
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&data[i], len);
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}
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if (count)
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tty_flip_buffer_push(&port->port);
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}
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static struct usb_serial_driver aircable_device = {
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.driver = {
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.owner = THIS_MODULE,
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.name = "aircable",
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},
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.id_table = id_table,
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.bulk_out_size = HCI_COMPLETE_FRAME,
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.calc_num_ports = aircable_calc_num_ports,
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.process_read_urb = aircable_process_read_urb,
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.prepare_write_buffer = aircable_prepare_write_buffer,
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.throttle = usb_serial_generic_throttle,
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.unthrottle = usb_serial_generic_unthrottle,
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};
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static struct usb_serial_driver * const serial_drivers[] = {
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&aircable_device, NULL
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};
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module_usb_serial_driver(serial_drivers, id_table);
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MODULE_AUTHOR(DRIVER_AUTHOR);
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MODULE_DESCRIPTION(DRIVER_DESC);
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MODULE_LICENSE("GPL v2");
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