1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * USB Wishbone-Serial adapter driver
4 *
5 * Copyright (C) 2013 Wesley W. Terpstra <w.terpstra@gsi.de>
6 * Copyright (C) 2013 GSI Helmholtz Centre for Heavy Ion Research GmbH
7 */
8
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 #include <linux/uaccess.h>
15
16 #define GSI_VENDOR_OPENCLOSE 0xB0
17
18 static const struct usb_device_id id_table[] = {
19 { USB_DEVICE_AND_INTERFACE_INFO(0x1D50, 0x6062, 0xFF, 0xFF, 0xFF) },
20 { },
21 };
22 MODULE_DEVICE_TABLE(usb, id_table);
23
24 /*
25 * Etherbone must be told that a new stream has begun before data arrives.
26 * This is necessary to restart the negotiation of Wishbone bus parameters.
27 * Similarly, when the stream ends, Etherbone must be told so that the cycle
28 * line can be driven low in the case that userspace failed to do so.
29 */
usb_gsi_openclose(struct usb_serial_port * port,int value)30 static int usb_gsi_openclose(struct usb_serial_port *port, int value)
31 {
32 struct usb_device *dev = port->serial->dev;
33
34 return usb_control_msg(
35 dev,
36 usb_sndctrlpipe(dev, 0), /* Send to EP0OUT */
37 GSI_VENDOR_OPENCLOSE,
38 USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
39 value, /* wValue = device is open(1) or closed(0) */
40 port->serial->interface->cur_altsetting->desc.bInterfaceNumber,
41 NULL, 0, /* There is no data stage */
42 5000); /* Timeout till operation fails */
43 }
44
wishbone_serial_open(struct tty_struct * tty,struct usb_serial_port * port)45 static int wishbone_serial_open(struct tty_struct *tty,
46 struct usb_serial_port *port)
47 {
48 int retval;
49
50 retval = usb_gsi_openclose(port, 1);
51 if (retval) {
52 dev_err(&port->serial->dev->dev,
53 "Could not mark device as open (%d)\n",
54 retval);
55 return retval;
56 }
57
58 retval = usb_serial_generic_open(tty, port);
59 if (retval)
60 usb_gsi_openclose(port, 0);
61
62 return retval;
63 }
64
wishbone_serial_close(struct usb_serial_port * port)65 static void wishbone_serial_close(struct usb_serial_port *port)
66 {
67 usb_serial_generic_close(port);
68 usb_gsi_openclose(port, 0);
69 }
70
71 static struct usb_serial_driver wishbone_serial_device = {
72 .driver = {
73 .owner = THIS_MODULE,
74 .name = "wishbone_serial",
75 },
76 .id_table = id_table,
77 .num_ports = 1,
78 .open = &wishbone_serial_open,
79 .close = &wishbone_serial_close,
80 };
81
82 static struct usb_serial_driver * const serial_drivers[] = {
83 &wishbone_serial_device, NULL
84 };
85
86 module_usb_serial_driver(serial_drivers, id_table);
87
88 MODULE_AUTHOR("Wesley W. Terpstra <w.terpstra@gsi.de>");
89 MODULE_DESCRIPTION("USB Wishbone-Serial adapter");
90 MODULE_LICENSE("GPL");
91
