1 /*
2 * USB Wishbone-Serial adapter driver
3 *
4 * Copyright (C) 2013 Wesley W. Terpstra <w.terpstra@gsi.de>
5 * Copyright (C) 2013 GSI Helmholtz Centre for Heavy Ion Research GmbH
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version 2
10 * of the License, or (at your option) any later version.
11 */
12
13 #include <linux/kernel.h>
14 #include <linux/tty.h>
15 #include <linux/module.h>
16 #include <linux/usb.h>
17 #include <linux/usb/serial.h>
18 #include <linux/uaccess.h>
19
20 #define GSI_VENDOR_OPENCLOSE 0xB0
21
22 static const struct usb_device_id id_table[] = {
23 { USB_DEVICE_AND_INTERFACE_INFO(0x1D50, 0x6062, 0xFF, 0xFF, 0xFF) },
24 { },
25 };
26 MODULE_DEVICE_TABLE(usb, id_table);
27
28 /*
29 * Etherbone must be told that a new stream has begun before data arrives.
30 * This is necessary to restart the negotiation of Wishbone bus parameters.
31 * Similarly, when the stream ends, Etherbone must be told so that the cycle
32 * line can be driven low in the case that userspace failed to do so.
33 */
usb_gsi_openclose(struct usb_serial_port * port,int value)34 static int usb_gsi_openclose(struct usb_serial_port *port, int value)
35 {
36 struct usb_device *dev = port->serial->dev;
37
38 return usb_control_msg(
39 dev,
40 usb_sndctrlpipe(dev, 0), /* Send to EP0OUT */
41 GSI_VENDOR_OPENCLOSE,
42 USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
43 value, /* wValue = device is open(1) or closed(0) */
44 port->serial->interface->cur_altsetting->desc.bInterfaceNumber,
45 NULL, 0, /* There is no data stage */
46 5000); /* Timeout till operation fails */
47 }
48
wishbone_serial_open(struct tty_struct * tty,struct usb_serial_port * port)49 static int wishbone_serial_open(struct tty_struct *tty,
50 struct usb_serial_port *port)
51 {
52 int retval;
53
54 retval = usb_gsi_openclose(port, 1);
55 if (retval) {
56 dev_err(&port->serial->dev->dev,
57 "Could not mark device as open (%d)\n",
58 retval);
59 return retval;
60 }
61
62 retval = usb_serial_generic_open(tty, port);
63 if (retval)
64 usb_gsi_openclose(port, 0);
65
66 return retval;
67 }
68
wishbone_serial_close(struct usb_serial_port * port)69 static void wishbone_serial_close(struct usb_serial_port *port)
70 {
71 usb_serial_generic_close(port);
72 usb_gsi_openclose(port, 0);
73 }
74
75 static struct usb_serial_driver wishbone_serial_device = {
76 .driver = {
77 .owner = THIS_MODULE,
78 .name = "wishbone_serial",
79 },
80 .id_table = id_table,
81 .num_ports = 1,
82 .open = &wishbone_serial_open,
83 .close = &wishbone_serial_close,
84 };
85
86 static struct usb_serial_driver * const serial_drivers[] = {
87 &wishbone_serial_device, NULL
88 };
89
90 module_usb_serial_driver(serial_drivers, id_table);
91
92 MODULE_AUTHOR("Wesley W. Terpstra <w.terpstra@gsi.de>");
93 MODULE_DESCRIPTION("USB Wishbone-Serial adapter");
94 MODULE_LICENSE("GPL");
95