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 USB_DEBUG_MAX_PACKET_SIZE 8 20 #define USB_DEBUG_BRK_SIZE 8 21 static char USB_DEBUG_BRK[USB_DEBUG_BRK_SIZE] = { 22 0x00, 23 0xff, 24 0x01, 25 0xfe, 26 0x00, 27 0xfe, 28 0x01, 29 0xff, 30 }; 31 32 static const struct usb_device_id id_table[] = { 33 { USB_DEVICE(0x0525, 0x127a) }, 34 { }, 35 }; 36 MODULE_DEVICE_TABLE(usb, id_table); 37 38 static struct usb_driver debug_driver = { 39 .name = "debug", 40 .probe = usb_serial_probe, 41 .disconnect = usb_serial_disconnect, 42 .id_table = id_table, 43 .no_dynamic_id = 1, 44 }; 45 46 /* This HW really does not support a serial break, so one will be 47 * emulated when ever the break state is set to true. 48 */ 49 static void usb_debug_break_ctl(struct tty_struct *tty, int break_state) 50 { 51 struct usb_serial_port *port = tty->driver_data; 52 if (!break_state) 53 return; 54 usb_serial_generic_write(tty, port, USB_DEBUG_BRK, USB_DEBUG_BRK_SIZE); 55 } 56 57 static void usb_debug_read_bulk_callback(struct urb *urb) 58 { 59 struct usb_serial_port *port = urb->context; 60 61 if (urb->actual_length == USB_DEBUG_BRK_SIZE && 62 memcmp(urb->transfer_buffer, USB_DEBUG_BRK, 63 USB_DEBUG_BRK_SIZE) == 0) { 64 usb_serial_handle_break(port); 65 usb_serial_generic_submit_read_urb(port, GFP_ATOMIC); 66 return; 67 } 68 69 usb_serial_generic_read_bulk_callback(urb); 70 } 71 72 static struct usb_serial_driver debug_device = { 73 .driver = { 74 .owner = THIS_MODULE, 75 .name = "debug", 76 }, 77 .id_table = id_table, 78 .usb_driver = &debug_driver, 79 .num_ports = 1, 80 .bulk_out_size = USB_DEBUG_MAX_PACKET_SIZE, 81 .break_ctl = usb_debug_break_ctl, 82 .read_bulk_callback = usb_debug_read_bulk_callback, 83 }; 84 85 static int __init debug_init(void) 86 { 87 int retval; 88 89 retval = usb_serial_register(&debug_device); 90 if (retval) 91 return retval; 92 retval = usb_register(&debug_driver); 93 if (retval) 94 usb_serial_deregister(&debug_device); 95 return retval; 96 } 97 98 static void __exit debug_exit(void) 99 { 100 usb_deregister(&debug_driver); 101 usb_serial_deregister(&debug_device); 102 } 103 104 module_init(debug_init); 105 module_exit(debug_exit); 106 MODULE_LICENSE("GPL"); 107