cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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wishbone-serial.c (2408B)

      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
     18static const struct usb_device_id id_table[] = {
     19	{ USB_DEVICE_AND_INTERFACE_INFO(0x1D50, 0x6062, 0xFF, 0xFF, 0xFF) },
     20	{ },
     21};
     22MODULE_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 */
     30static 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
     45static 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
     65static void wishbone_serial_close(struct usb_serial_port *port)
     66{
     67	usb_serial_generic_close(port);
     68	usb_gsi_openclose(port, 0);
     69}
     70
     71static 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
     82static struct usb_serial_driver * const serial_drivers[] = {
     83	&wishbone_serial_device, NULL
     84};
     85
     86module_usb_serial_driver(serial_drivers, id_table);
     87
     88MODULE_AUTHOR("Wesley W. Terpstra <w.terpstra@gsi.de>");
     89MODULE_DESCRIPTION("USB Wishbone-Serial adapter");
     90MODULE_LICENSE("GPL");