1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * USB Debug cable driver 4 * 5 * Copyright (C) 2006 Greg Kroah-Hartman <greg@kroah.com> 6 */ 7 8 #include <linux/gfp.h> 9 #include <linux/kernel.h> 10 #include <linux/tty.h> 11 #include <linux/module.h> 12 #include <linux/usb.h> 13 #include <linux/usb/serial.h> 14 15 #define USB_DEBUG_MAX_PACKET_SIZE 8 16 #define USB_DEBUG_BRK_SIZE 8 17 static const char USB_DEBUG_BRK[USB_DEBUG_BRK_SIZE] = { 18 0x00, 19 0xff, 20 0x01, 21 0xfe, 22 0x00, 23 0xfe, 24 0x01, 25 0xff, 26 }; 27 28 static const struct usb_device_id id_table[] = { 29 { USB_DEVICE(0x0525, 0x127a) }, 30 { }, 31 }; 32 33 static const struct usb_device_id dbc_id_table[] = { 34 { USB_DEVICE(0x1d6b, 0x0010) }, 35 { USB_DEVICE(0x1d6b, 0x0011) }, 36 { }, 37 }; 38 39 static const struct usb_device_id id_table_combined[] = { 40 { USB_DEVICE(0x0525, 0x127a) }, 41 { USB_DEVICE(0x1d6b, 0x0010) }, 42 { USB_DEVICE(0x1d6b, 0x0011) }, 43 { }, 44 }; 45 MODULE_DEVICE_TABLE(usb, id_table_combined); 46 47 /* This HW really does not support a serial break, so one will be 48 * emulated when ever the break state is set to true. 49 */ 50 static void usb_debug_break_ctl(struct tty_struct *tty, int break_state) 51 { 52 struct usb_serial_port *port = tty->driver_data; 53 if (!break_state) 54 return; 55 usb_serial_generic_write(tty, port, USB_DEBUG_BRK, USB_DEBUG_BRK_SIZE); 56 } 57 58 static void usb_debug_process_read_urb(struct urb *urb) 59 { 60 struct usb_serial_port *port = urb->context; 61 62 if (urb->actual_length == USB_DEBUG_BRK_SIZE && 63 memcmp(urb->transfer_buffer, USB_DEBUG_BRK, 64 USB_DEBUG_BRK_SIZE) == 0) { 65 usb_serial_handle_break(port); 66 return; 67 } 68 69 usb_serial_generic_process_read_urb(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 .num_ports = 1, 79 .bulk_out_size = USB_DEBUG_MAX_PACKET_SIZE, 80 .break_ctl = usb_debug_break_ctl, 81 .process_read_urb = usb_debug_process_read_urb, 82 }; 83 84 static struct usb_serial_driver dbc_device = { 85 .driver = { 86 .owner = THIS_MODULE, 87 .name = "xhci_dbc", 88 }, 89 .id_table = dbc_id_table, 90 .num_ports = 1, 91 .break_ctl = usb_debug_break_ctl, 92 .process_read_urb = usb_debug_process_read_urb, 93 }; 94 95 static struct usb_serial_driver * const serial_drivers[] = { 96 &debug_device, &dbc_device, NULL 97 }; 98 99 module_usb_serial_driver(serial_drivers, id_table_combined); 100 MODULE_LICENSE("GPL v2"); 101