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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cypress_cy7c63.c (6463B)


      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3* cypress_cy7c63.c
      4*
      5* Copyright (c) 2006-2007 Oliver Bock (bock@tfh-berlin.de)
      6*
      7*	This driver is based on the Cypress USB Driver by Marcus Maul
      8*	(cyport) and the 2.0 version of Greg Kroah-Hartman's
      9*	USB Skeleton driver.
     10*
     11*	This is a generic driver for the Cypress CY7C63xxx family.
     12*	For the time being it enables you to read from and write to
     13*	the single I/O ports of the device.
     14*
     15*	Supported vendors:	AK Modul-Bus Computer GmbH
     16*				(Firmware "Port-Chip")
     17*
     18*	Supported devices:	CY7C63001A-PC
     19*				CY7C63001C-PXC
     20*				CY7C63001C-SXC
     21*
     22*	Supported functions:	Read/Write Ports
     23*
     24*
     25*	For up-to-date information please visit:
     26*	http://www.obock.de/kernel/cypress
     27*/
     28
     29#include <linux/module.h>
     30#include <linux/kernel.h>
     31#include <linux/slab.h>
     32#include <linux/usb.h>
     33
     34#define DRIVER_AUTHOR		"Oliver Bock (bock@tfh-berlin.de)"
     35#define DRIVER_DESC		"Cypress CY7C63xxx USB driver"
     36
     37#define CYPRESS_VENDOR_ID	0xa2c
     38#define CYPRESS_PRODUCT_ID	0x8
     39
     40#define CYPRESS_READ_PORT	0x4
     41#define CYPRESS_WRITE_PORT	0x5
     42
     43#define CYPRESS_READ_RAM	0x2
     44#define CYPRESS_WRITE_RAM	0x3
     45#define CYPRESS_READ_ROM	0x1
     46
     47#define CYPRESS_READ_PORT_ID0	0
     48#define CYPRESS_WRITE_PORT_ID0	0
     49#define CYPRESS_READ_PORT_ID1	0x2
     50#define CYPRESS_WRITE_PORT_ID1	1
     51
     52#define CYPRESS_MAX_REQSIZE	8
     53
     54
     55/* table of devices that work with this driver */
     56static const struct usb_device_id cypress_table[] = {
     57	{ USB_DEVICE(CYPRESS_VENDOR_ID, CYPRESS_PRODUCT_ID) },
     58	{ }
     59};
     60MODULE_DEVICE_TABLE(usb, cypress_table);
     61
     62/* structure to hold all of our device specific stuff */
     63struct cypress {
     64	struct usb_device *	udev;
     65	unsigned char		port[2];
     66};
     67
     68/* used to send usb control messages to device */
     69static int vendor_command(struct cypress *dev, unsigned char request,
     70			  unsigned char address, unsigned char data)
     71{
     72	int retval = 0;
     73	unsigned int pipe;
     74	unsigned char *iobuf;
     75
     76	/* allocate some memory for the i/o buffer*/
     77	iobuf = kzalloc(CYPRESS_MAX_REQSIZE, GFP_KERNEL);
     78	if (!iobuf) {
     79		retval = -ENOMEM;
     80		goto error;
     81	}
     82
     83	dev_dbg(&dev->udev->dev, "Sending usb_control_msg (data: %d)\n", data);
     84
     85	/* prepare usb control message and send it upstream */
     86	pipe = usb_rcvctrlpipe(dev->udev, 0);
     87	retval = usb_control_msg(dev->udev, pipe, request,
     88				 USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_OTHER,
     89				 address, data, iobuf, CYPRESS_MAX_REQSIZE,
     90				 USB_CTRL_GET_TIMEOUT);
     91
     92	/* store returned data (more READs to be added) */
     93	switch (request) {
     94		case CYPRESS_READ_PORT:
     95			if (address == CYPRESS_READ_PORT_ID0) {
     96				dev->port[0] = iobuf[1];
     97				dev_dbg(&dev->udev->dev,
     98					"READ_PORT0 returned: %d\n",
     99					dev->port[0]);
    100			}
    101			else if (address == CYPRESS_READ_PORT_ID1) {
    102				dev->port[1] = iobuf[1];
    103				dev_dbg(&dev->udev->dev,
    104					"READ_PORT1 returned: %d\n",
    105					dev->port[1]);
    106			}
    107			break;
    108	}
    109
    110	kfree(iobuf);
    111error:
    112	return retval;
    113}
    114
    115/* write port value */
    116static ssize_t write_port(struct device *dev, struct device_attribute *attr,
    117			  const char *buf, size_t count,
    118			  int port_num, int write_id)
    119{
    120	int value = -1;
    121	int result = 0;
    122
    123	struct usb_interface *intf = to_usb_interface(dev);
    124	struct cypress *cyp = usb_get_intfdata(intf);
    125
    126	dev_dbg(&cyp->udev->dev, "WRITE_PORT%d called\n", port_num);
    127
    128	/* validate input data */
    129	if (sscanf(buf, "%d", &value) < 1) {
    130		result = -EINVAL;
    131		goto error;
    132	}
    133	if (value < 0 || value > 255) {
    134		result = -EINVAL;
    135		goto error;
    136	}
    137
    138	result = vendor_command(cyp, CYPRESS_WRITE_PORT, write_id,
    139				(unsigned char)value);
    140
    141	dev_dbg(&cyp->udev->dev, "Result of vendor_command: %d\n\n", result);
    142error:
    143	return result < 0 ? result : count;
    144}
    145
    146/* attribute callback handler (write) */
    147static ssize_t port0_store(struct device *dev,
    148				 struct device_attribute *attr,
    149				 const char *buf, size_t count)
    150{
    151	return write_port(dev, attr, buf, count, 0, CYPRESS_WRITE_PORT_ID0);
    152}
    153
    154/* attribute callback handler (write) */
    155static ssize_t port1_store(struct device *dev,
    156				 struct device_attribute *attr,
    157				 const char *buf, size_t count)
    158{
    159	return write_port(dev, attr, buf, count, 1, CYPRESS_WRITE_PORT_ID1);
    160}
    161
    162/* read port value */
    163static ssize_t read_port(struct device *dev, struct device_attribute *attr,
    164			 char *buf, int port_num, int read_id)
    165{
    166	int result = 0;
    167
    168	struct usb_interface *intf = to_usb_interface(dev);
    169	struct cypress *cyp = usb_get_intfdata(intf);
    170
    171	dev_dbg(&cyp->udev->dev, "READ_PORT%d called\n", port_num);
    172
    173	result = vendor_command(cyp, CYPRESS_READ_PORT, read_id, 0);
    174
    175	dev_dbg(&cyp->udev->dev, "Result of vendor_command: %d\n\n", result);
    176
    177	return sprintf(buf, "%d", cyp->port[port_num]);
    178}
    179
    180/* attribute callback handler (read) */
    181static ssize_t port0_show(struct device *dev,
    182				 struct device_attribute *attr, char *buf)
    183{
    184	return read_port(dev, attr, buf, 0, CYPRESS_READ_PORT_ID0);
    185}
    186static DEVICE_ATTR_RW(port0);
    187
    188/* attribute callback handler (read) */
    189static ssize_t port1_show(struct device *dev,
    190				 struct device_attribute *attr, char *buf)
    191{
    192	return read_port(dev, attr, buf, 1, CYPRESS_READ_PORT_ID1);
    193}
    194static DEVICE_ATTR_RW(port1);
    195
    196static struct attribute *cypress_attrs[] = {
    197	&dev_attr_port0.attr,
    198	&dev_attr_port1.attr,
    199	NULL,
    200};
    201ATTRIBUTE_GROUPS(cypress);
    202
    203static int cypress_probe(struct usb_interface *interface,
    204			 const struct usb_device_id *id)
    205{
    206	struct cypress *dev = NULL;
    207	int retval = -ENOMEM;
    208
    209	/* allocate memory for our device state and initialize it */
    210	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
    211	if (!dev)
    212		goto error_mem;
    213
    214	dev->udev = usb_get_dev(interface_to_usbdev(interface));
    215
    216	/* save our data pointer in this interface device */
    217	usb_set_intfdata(interface, dev);
    218
    219	/* let the user know that the device is now attached */
    220	dev_info(&interface->dev,
    221		 "Cypress CY7C63xxx device now attached\n");
    222	return 0;
    223
    224error_mem:
    225	return retval;
    226}
    227
    228static void cypress_disconnect(struct usb_interface *interface)
    229{
    230	struct cypress *dev;
    231
    232	dev = usb_get_intfdata(interface);
    233
    234	/* the intfdata can be set to NULL only after the
    235	 * device files have been removed */
    236	usb_set_intfdata(interface, NULL);
    237
    238	usb_put_dev(dev->udev);
    239
    240	dev_info(&interface->dev,
    241		 "Cypress CY7C63xxx device now disconnected\n");
    242
    243	kfree(dev);
    244}
    245
    246static struct usb_driver cypress_driver = {
    247	.name = "cypress_cy7c63",
    248	.probe = cypress_probe,
    249	.disconnect = cypress_disconnect,
    250	.id_table = cypress_table,
    251	.dev_groups = cypress_groups,
    252};
    253
    254module_usb_driver(cypress_driver);
    255
    256MODULE_AUTHOR(DRIVER_AUTHOR);
    257MODULE_DESCRIPTION(DRIVER_DESC);
    258
    259MODULE_LICENSE("GPL");