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 */ 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 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 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