wishbone-serial.c
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/*
* USB Wishbone-Serial adapter driver
*
* Copyright (C) 2013 Wesley W. Terpstra <w.terpstra@gsi.de>
* Copyright (C) 2013 GSI Helmholtz Centre for Heavy Ion Research GmbH
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*/
#include <linux/kernel.h>
#include <linux/tty.h>
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
#include <linux/uaccess.h>
#define GSI_VENDOR_OPENCLOSE 0xB0
static const struct usb_device_id id_table[] = {
{ USB_DEVICE_AND_INTERFACE_INFO(0x1D50, 0x6062, 0xFF, 0xFF, 0xFF) },
{ },
};
MODULE_DEVICE_TABLE(usb, id_table);
/*
* Etherbone must be told that a new stream has begun before data arrives.
* This is necessary to restart the negotiation of Wishbone bus parameters.
* Similarly, when the stream ends, Etherbone must be told so that the cycle
* line can be driven low in the case that userspace failed to do so.
*/
static int usb_gsi_openclose(struct usb_serial_port *port, int value)
{
struct usb_device *dev = port->serial->dev;
return usb_control_msg(
dev,
usb_sndctrlpipe(dev, 0), /* Send to EP0OUT */
GSI_VENDOR_OPENCLOSE,
USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
value, /* wValue = device is open(1) or closed(0) */
port->serial->interface->cur_altsetting->desc.bInterfaceNumber,
NULL, 0, /* There is no data stage */
5000); /* Timeout till operation fails */
}
static int wishbone_serial_open(struct tty_struct *tty,
struct usb_serial_port *port)
{
int retval;
retval = usb_gsi_openclose(port, 1);
if (retval) {
dev_err(&port->serial->dev->dev,
"Could not mark device as open (%d)\n",
retval);
return retval;
}
retval = usb_serial_generic_open(tty, port);
if (retval)
usb_gsi_openclose(port, 0);
return retval;
}
static void wishbone_serial_close(struct usb_serial_port *port)
{
usb_serial_generic_close(port);
usb_gsi_openclose(port, 0);
}
static struct usb_serial_driver wishbone_serial_device = {
.driver = {
.owner = THIS_MODULE,
.name = "wishbone_serial",
},
.id_table = id_table,
.num_ports = 1,
.open = &wishbone_serial_open,
.close = &wishbone_serial_close,
};
static struct usb_serial_driver * const serial_drivers[] = {
&wishbone_serial_device, NULL
};
module_usb_serial_driver(serial_drivers, id_table);
MODULE_AUTHOR("Wesley W. Terpstra <w.terpstra@gsi.de>");
MODULE_DESCRIPTION("USB Wishbone-Serial adapter");
MODULE_LICENSE("GPL");