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/tty.h> 14 #include <linux/module.h> 15 #include <linux/usb.h> 16 #include <linux/usb/serial.h> 17 18 #define USB_DEBUG_MAX_PACKET_SIZE 8 19 #define USB_DEBUG_BRK_SIZE 8 20 static char USB_DEBUG_BRK[USB_DEBUG_BRK_SIZE] = { 21 0x00, 22 0xff, 23 0x01, 24 0xfe, 25 0x00, 26 0xfe, 27 0x01, 28 0xff, 29 }; 30 31 static const struct usb_device_id id_table[] = { 32 { USB_DEVICE(0x0525, 0x127a) }, 33 { }, 34 }; 35 MODULE_DEVICE_TABLE(usb, id_table); 36 37 /* This HW really does not support a serial break, so one will be 38 * emulated when ever the break state is set to true. 39 */ 40 static void usb_debug_break_ctl(struct tty_struct *tty, int break_state) 41 { 42 struct usb_serial_port *port = tty->driver_data; 43 if (!break_state) 44 return; 45 usb_serial_generic_write(tty, port, USB_DEBUG_BRK, USB_DEBUG_BRK_SIZE); 46 } 47 48 static void usb_debug_process_read_urb(struct urb *urb) 49 { 50 struct usb_serial_port *port = urb->context; 51 52 if (urb->actual_length == USB_DEBUG_BRK_SIZE && 53 memcmp(urb->transfer_buffer, USB_DEBUG_BRK, 54 USB_DEBUG_BRK_SIZE) == 0) { 55 usb_serial_handle_break(port); 56 return; 57 } 58 59 usb_serial_generic_process_read_urb(urb); 60 } 61 62 static struct usb_serial_driver debug_device = { 63 .driver = { 64 .owner = THIS_MODULE, 65 .name = "debug", 66 }, 67 .id_table = id_table, 68 .num_ports = 1, 69 .bulk_out_size = USB_DEBUG_MAX_PACKET_SIZE, 70 .break_ctl = usb_debug_break_ctl, 71 .process_read_urb = usb_debug_process_read_urb, 72 }; 73 74 static struct usb_serial_driver * const serial_drivers[] = { 75 &debug_device, NULL 76 }; 77 78 module_usb_serial_driver(serial_drivers, id_table); 79 MODULE_LICENSE("GPL"); 80