usb/serial/usb_debug.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * USB Debug cable driver
0004  *
0005  * Copyright (C) 2006 Greg Kroah-Hartman <greg@kroah.com>
0006  */
0007
0008 #include <linux/gfp.h>
0009 #include <linux/kernel.h>
0010 #include <linux/tty.h>
0011 #include <linux/module.h>
0012 #include <linux/usb.h>
0013 #include <linux/usb/serial.h>
0014
0015 #define USB_DEBUG_MAX_PACKET_SIZE   8
0016 #define USB_DEBUG_BRK_SIZE      8
0017 static const char USB_DEBUG_BRK[USB_DEBUG_BRK_SIZE] = {
0018     0x00,
0019     0xff,
0020     0x01,
0021     0xfe,
0022     0x00,
0023     0xfe,
0024     0x01,
0025     0xff,
0026 };
0027
0028 static const struct usb_device_id id_table[] = {
0029     { USB_DEVICE(0x0525, 0x127a) },
0030     { },
0031 };
0032
0033 static const struct usb_device_id dbc_id_table[] = {
0034     { USB_DEVICE(0x1d6b, 0x0010) },
0035     { USB_DEVICE(0x1d6b, 0x0011) },
0036     { },
0037 };
0038
0039 static const struct usb_device_id id_table_combined[] = {
0040     { USB_DEVICE(0x0525, 0x127a) },
0041     { USB_DEVICE(0x1d6b, 0x0010) },
0042     { USB_DEVICE(0x1d6b, 0x0011) },
0043     { },
0044 };
0045 MODULE_DEVICE_TABLE(usb, id_table_combined);
0046
0047 /* This HW really does not support a serial break, so one will be
0048  * emulated when ever the break state is set to true.
0049  */
0050 static void usb_debug_break_ctl(struct tty_struct *tty, int break_state)
0051 {
0052     struct usb_serial_port *port = tty->driver_data;
0053     if (!break_state)
0054         return;
0055     usb_serial_generic_write(tty, port, USB_DEBUG_BRK, USB_DEBUG_BRK_SIZE);
0056 }
0057
0058 static void usb_debug_process_read_urb(struct urb *urb)
0059 {
0060     struct usb_serial_port *port = urb->context;
0061
0062     if (urb->actual_length == USB_DEBUG_BRK_SIZE &&
0063         memcmp(urb->transfer_buffer, USB_DEBUG_BRK,
0064                         USB_DEBUG_BRK_SIZE) == 0) {
0065         usb_serial_handle_break(port);
0066         return;
0067     }
0068
0069     usb_serial_generic_process_read_urb(urb);
0070 }
0071
0072 static struct usb_serial_driver debug_device = {
0073     .driver = {
0074         .owner =    THIS_MODULE,
0075         .name =     "debug",
0076     },
0077     .id_table =     id_table,
0078     .num_ports =        1,
0079     .bulk_out_size =    USB_DEBUG_MAX_PACKET_SIZE,
0080     .break_ctl =        usb_debug_break_ctl,
0081     .process_read_urb = usb_debug_process_read_urb,
0082 };
0083
0084 static struct usb_serial_driver dbc_device = {
0085     .driver = {
0086         .owner =    THIS_MODULE,
0087         .name =     "xhci_dbc",
0088     },
0089     .id_table =     dbc_id_table,
0090     .num_ports =        1,
0091     .break_ctl =        usb_debug_break_ctl,
0092     .process_read_urb = usb_debug_process_read_urb,
0093 };
0094
0095 static struct usb_serial_driver * const serial_drivers[] = {
0096     &debug_device, &dbc_device, NULL
0097 };
0098
0099 module_usb_serial_driver(serial_drivers, id_table_combined);
0100 MODULE_LICENSE("GPL v2");