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 /* This HW really does not support a serial break, so one will be 39 * emulated when ever the break state is set to true. 40 */ 41 static void usb_debug_break_ctl(struct tty_struct *tty, int break_state) 42 { 43 struct usb_serial_port *port = tty->driver_data; 44 if (!break_state) 45 return; 46 usb_serial_generic_write(tty, port, USB_DEBUG_BRK, USB_DEBUG_BRK_SIZE); 47 } 48 49 static void usb_debug_process_read_urb(struct urb *urb) 50 { 51 struct usb_serial_port *port = urb->context; 52 53 if (urb->actual_length == USB_DEBUG_BRK_SIZE && 54 memcmp(urb->transfer_buffer, USB_DEBUG_BRK, 55 USB_DEBUG_BRK_SIZE) == 0) { 56 usb_serial_handle_break(port); 57 return; 58 } 59 60 usb_serial_generic_process_read_urb(urb); 61 } 62 63 static struct usb_serial_driver debug_device = { 64 .driver = { 65 .owner = THIS_MODULE, 66 .name = "debug", 67 }, 68 .id_table = id_table, 69 .num_ports = 1, 70 .bulk_out_size = USB_DEBUG_MAX_PACKET_SIZE, 71 .break_ctl = usb_debug_break_ctl, 72 .process_read_urb = usb_debug_process_read_urb, 73 }; 74 75 static struct usb_serial_driver * const serial_drivers[] = { 76 &debug_device, NULL 77 }; 78 79 module_usb_serial_driver(serial_drivers, id_table); 80 MODULE_LICENSE("GPL"); 81