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 | */ |
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 | index: port->serial->interface->cur_altsetting->desc.bInterfaceNumber, |
41 | NULL, size: 0, /* There is no data stage */ |
42 | timeout: 5000); /* Timeout till operation fails */ |
43 | } |
44 | |
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, value: 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, value: 0); |
61 | |
62 | return retval; |
63 | } |
64 | |
65 | static void wishbone_serial_close(struct usb_serial_port *port) |
66 | { |
67 | usb_serial_generic_close(port); |
68 | usb_gsi_openclose(port, value: 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 | |