1 /* 2 * USB Debug cable driver 3 * 4 * Copyright (C) 2006 Greg Kroah-Hartman <greg@kroah.com> 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License version 8 * 2 as published by the Free Software Foundation. 9 */ 10 11 #include <linux/gfp.h> 12 #include <linux/kernel.h> 13 #include <linux/init.h> 14 #include <linux/tty.h> 15 #include <linux/module.h> 16 #include <linux/usb.h> 17 #include <linux/usb/serial.h> 18 19 #define URB_DEBUG_MAX_IN_FLIGHT_URBS 4000 20 #define USB_DEBUG_MAX_PACKET_SIZE 8 21 #define USB_DEBUG_BRK_SIZE 8 22 static char USB_DEBUG_BRK[USB_DEBUG_BRK_SIZE] = { 23 0x00, 24 0xff, 25 0x01, 26 0xfe, 27 0x00, 28 0xfe, 29 0x01, 30 0xff, 31 }; 32 33 static const struct usb_device_id id_table[] = { 34 { USB_DEVICE(0x0525, 0x127a) }, 35 { }, 36 }; 37 MODULE_DEVICE_TABLE(usb, id_table); 38 39 static struct usb_driver debug_driver = { 40 .name = "debug", 41 .probe = usb_serial_probe, 42 .disconnect = usb_serial_disconnect, 43 .id_table = id_table, 44 .no_dynamic_id = 1, 45 }; 46 47 static int usb_debug_open(struct tty_struct *tty, struct usb_serial_port *port) 48 { 49 port->bulk_out_size = USB_DEBUG_MAX_PACKET_SIZE; 50 return usb_serial_generic_open(tty, port); 51 } 52 53 /* This HW really does not support a serial break, so one will be 54 * emulated when ever the break state is set to true. 55 */ 56 static void usb_debug_break_ctl(struct tty_struct *tty, int break_state) 57 { 58 struct usb_serial_port *port = tty->driver_data; 59 if (!break_state) 60 return; 61 usb_serial_generic_write(tty, port, USB_DEBUG_BRK, USB_DEBUG_BRK_SIZE); 62 } 63 64 static void usb_debug_read_bulk_callback(struct urb *urb) 65 { 66 struct usb_serial_port *port = urb->context; 67 68 if (urb->actual_length == USB_DEBUG_BRK_SIZE && 69 memcmp(urb->transfer_buffer, USB_DEBUG_BRK, 70 USB_DEBUG_BRK_SIZE) == 0) { 71 usb_serial_handle_break(port); 72 usb_serial_generic_resubmit_read_urb(port, GFP_ATOMIC); 73 return; 74 } 75 76 usb_serial_generic_read_bulk_callback(urb); 77 } 78 79 static struct usb_serial_driver debug_device = { 80 .driver = { 81 .owner = THIS_MODULE, 82 .name = "debug", 83 }, 84 .id_table = id_table, 85 .num_ports = 1, 86 .open = usb_debug_open, 87 .max_in_flight_urbs = URB_DEBUG_MAX_IN_FLIGHT_URBS, 88 .break_ctl = usb_debug_break_ctl, 89 .read_bulk_callback = usb_debug_read_bulk_callback, 90 }; 91 92 static int __init debug_init(void) 93 { 94 int retval; 95 96 retval = usb_serial_register(&debug_device); 97 if (retval) 98 return retval; 99 retval = usb_register(&debug_driver); 100 if (retval) 101 usb_serial_deregister(&debug_device); 102 return retval; 103 } 104 105 static void __exit debug_exit(void) 106 { 107 usb_deregister(&debug_driver); 108 usb_serial_deregister(&debug_device); 109 } 110 111 module_init(debug_init); 112 module_exit(debug_exit); 113 MODULE_LICENSE("GPL"); 114