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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cm4040_cs.c (15786B)


      1/*
      2 * A driver for the Omnikey PCMCIA smartcard reader CardMan 4040
      3 *
      4 * (c) 2000-2004 Omnikey AG (http://www.omnikey.com/)
      5 *
      6 * (C) 2005-2006 Harald Welte <laforge@gnumonks.org>
      7 * 	- add support for poll()
      8 * 	- driver cleanup
      9 * 	- add waitqueues
     10 * 	- adhere to linux kernel coding style and policies
     11 * 	- support 2.6.13 "new style" pcmcia interface
     12 * 	- add class interface for udev device creation
     13 *
     14 * The device basically is a USB CCID compliant device that has been
     15 * attached to an I/O-Mapped FIFO.
     16 *
     17 * All rights reserved, Dual BSD/GPL Licensed.
     18 */
     19
     20#include <linux/kernel.h>
     21#include <linux/module.h>
     22#include <linux/slab.h>
     23#include <linux/init.h>
     24#include <linux/fs.h>
     25#include <linux/delay.h>
     26#include <linux/poll.h>
     27#include <linux/mutex.h>
     28#include <linux/wait.h>
     29#include <linux/uaccess.h>
     30#include <asm/io.h>
     31
     32#include <pcmcia/cistpl.h>
     33#include <pcmcia/cisreg.h>
     34#include <pcmcia/ciscode.h>
     35#include <pcmcia/ds.h>
     36
     37#include "cm4040_cs.h"
     38
     39
     40#define reader_to_dev(x)	(&x->p_dev->dev)
     41
     42/* n (debug level) is ignored */
     43/* additional debug output may be enabled by re-compiling with
     44 * CM4040_DEBUG set */
     45/* #define CM4040_DEBUG */
     46#define DEBUGP(n, rdr, x, args...) do { 		\
     47		dev_dbg(reader_to_dev(rdr), "%s:" x, 	\
     48			   __func__ , ## args);		\
     49	} while (0)
     50
     51static DEFINE_MUTEX(cm4040_mutex);
     52
     53#define	CCID_DRIVER_BULK_DEFAULT_TIMEOUT  	(150*HZ)
     54#define	CCID_DRIVER_ASYNC_POWERUP_TIMEOUT 	(35*HZ)
     55#define	CCID_DRIVER_MINIMUM_TIMEOUT 		(3*HZ)
     56#define READ_WRITE_BUFFER_SIZE 512
     57#define POLL_LOOP_COUNT				1000
     58
     59/* how often to poll for fifo status change */
     60#define POLL_PERIOD 				msecs_to_jiffies(10)
     61
     62static void reader_release(struct pcmcia_device *link);
     63
     64static int major;
     65static struct class *cmx_class;
     66
     67#define		BS_READABLE	0x01
     68#define		BS_WRITABLE	0x02
     69
     70struct reader_dev {
     71	struct pcmcia_device	*p_dev;
     72	wait_queue_head_t	devq;
     73	wait_queue_head_t	poll_wait;
     74	wait_queue_head_t	read_wait;
     75	wait_queue_head_t	write_wait;
     76	unsigned long 	  	buffer_status;
     77	unsigned long     	timeout;
     78	unsigned char     	s_buf[READ_WRITE_BUFFER_SIZE];
     79	unsigned char     	r_buf[READ_WRITE_BUFFER_SIZE];
     80	struct timer_list 	poll_timer;
     81};
     82
     83static struct pcmcia_device *dev_table[CM_MAX_DEV];
     84
     85#ifndef CM4040_DEBUG
     86#define	xoutb	outb
     87#define	xinb	inb
     88#else
     89static inline void xoutb(unsigned char val, unsigned short port)
     90{
     91	pr_debug("outb(val=%.2x,port=%.4x)\n", val, port);
     92	outb(val, port);
     93}
     94
     95static inline unsigned char xinb(unsigned short port)
     96{
     97	unsigned char val;
     98
     99	val = inb(port);
    100	pr_debug("%.2x=inb(%.4x)\n", val, port);
    101	return val;
    102}
    103#endif
    104
    105/* poll the device fifo status register.  not to be confused with
    106 * the poll syscall. */
    107static void cm4040_do_poll(struct timer_list *t)
    108{
    109	struct reader_dev *dev = from_timer(dev, t, poll_timer);
    110	unsigned int obs = xinb(dev->p_dev->resource[0]->start
    111				+ REG_OFFSET_BUFFER_STATUS);
    112
    113	if ((obs & BSR_BULK_IN_FULL)) {
    114		set_bit(BS_READABLE, &dev->buffer_status);
    115		DEBUGP(4, dev, "waking up read_wait\n");
    116		wake_up_interruptible(&dev->read_wait);
    117	} else
    118		clear_bit(BS_READABLE, &dev->buffer_status);
    119
    120	if (!(obs & BSR_BULK_OUT_FULL)) {
    121		set_bit(BS_WRITABLE, &dev->buffer_status);
    122		DEBUGP(4, dev, "waking up write_wait\n");
    123		wake_up_interruptible(&dev->write_wait);
    124	} else
    125		clear_bit(BS_WRITABLE, &dev->buffer_status);
    126
    127	if (dev->buffer_status)
    128		wake_up_interruptible(&dev->poll_wait);
    129
    130	mod_timer(&dev->poll_timer, jiffies + POLL_PERIOD);
    131}
    132
    133static void cm4040_stop_poll(struct reader_dev *dev)
    134{
    135	del_timer_sync(&dev->poll_timer);
    136}
    137
    138static int wait_for_bulk_out_ready(struct reader_dev *dev)
    139{
    140	int i, rc;
    141	int iobase = dev->p_dev->resource[0]->start;
    142
    143	for (i = 0; i < POLL_LOOP_COUNT; i++) {
    144		if ((xinb(iobase + REG_OFFSET_BUFFER_STATUS)
    145		    & BSR_BULK_OUT_FULL) == 0) {
    146			DEBUGP(4, dev, "BulkOut empty (i=%d)\n", i);
    147			return 1;
    148		}
    149	}
    150
    151	DEBUGP(4, dev, "wait_event_interruptible_timeout(timeout=%ld\n",
    152		dev->timeout);
    153	rc = wait_event_interruptible_timeout(dev->write_wait,
    154					      test_and_clear_bit(BS_WRITABLE,
    155						       &dev->buffer_status),
    156					      dev->timeout);
    157
    158	if (rc > 0)
    159		DEBUGP(4, dev, "woke up: BulkOut empty\n");
    160	else if (rc == 0)
    161		DEBUGP(4, dev, "woke up: BulkOut full, returning 0 :(\n");
    162	else if (rc < 0)
    163		DEBUGP(4, dev, "woke up: signal arrived\n");
    164
    165	return rc;
    166}
    167
    168/* Write to Sync Control Register */
    169static int write_sync_reg(unsigned char val, struct reader_dev *dev)
    170{
    171	int iobase = dev->p_dev->resource[0]->start;
    172	int rc;
    173
    174	rc = wait_for_bulk_out_ready(dev);
    175	if (rc <= 0)
    176		return rc;
    177
    178	xoutb(val, iobase + REG_OFFSET_SYNC_CONTROL);
    179	rc = wait_for_bulk_out_ready(dev);
    180	if (rc <= 0)
    181		return rc;
    182
    183	return 1;
    184}
    185
    186static int wait_for_bulk_in_ready(struct reader_dev *dev)
    187{
    188	int i, rc;
    189	int iobase = dev->p_dev->resource[0]->start;
    190
    191	for (i = 0; i < POLL_LOOP_COUNT; i++) {
    192		if ((xinb(iobase + REG_OFFSET_BUFFER_STATUS)
    193		    & BSR_BULK_IN_FULL) == BSR_BULK_IN_FULL) {
    194			DEBUGP(3, dev, "BulkIn full (i=%d)\n", i);
    195			return 1;
    196		}
    197	}
    198
    199	DEBUGP(4, dev, "wait_event_interruptible_timeout(timeout=%ld\n",
    200		dev->timeout);
    201	rc = wait_event_interruptible_timeout(dev->read_wait,
    202					      test_and_clear_bit(BS_READABLE,
    203						 	&dev->buffer_status),
    204					      dev->timeout);
    205	if (rc > 0)
    206		DEBUGP(4, dev, "woke up: BulkIn full\n");
    207	else if (rc == 0)
    208		DEBUGP(4, dev, "woke up: BulkIn not full, returning 0 :(\n");
    209	else if (rc < 0)
    210		DEBUGP(4, dev, "woke up: signal arrived\n");
    211
    212	return rc;
    213}
    214
    215static ssize_t cm4040_read(struct file *filp, char __user *buf,
    216			size_t count, loff_t *ppos)
    217{
    218	struct reader_dev *dev = filp->private_data;
    219	int iobase = dev->p_dev->resource[0]->start;
    220	size_t bytes_to_read;
    221	unsigned long i;
    222	size_t min_bytes_to_read;
    223	int rc;
    224
    225	DEBUGP(2, dev, "-> cm4040_read(%s,%d)\n", current->comm, current->pid);
    226
    227	if (count == 0)
    228		return 0;
    229
    230	if (count < 10)
    231		return -EFAULT;
    232
    233	if (filp->f_flags & O_NONBLOCK) {
    234		DEBUGP(4, dev, "filep->f_flags O_NONBLOCK set\n");
    235		DEBUGP(2, dev, "<- cm4040_read (failure)\n");
    236		return -EAGAIN;
    237	}
    238
    239	if (!pcmcia_dev_present(dev->p_dev))
    240		return -ENODEV;
    241
    242	for (i = 0; i < 5; i++) {
    243		rc = wait_for_bulk_in_ready(dev);
    244		if (rc <= 0) {
    245			DEBUGP(5, dev, "wait_for_bulk_in_ready rc=%.2x\n", rc);
    246			DEBUGP(2, dev, "<- cm4040_read (failed)\n");
    247			if (rc == -ERESTARTSYS)
    248				return rc;
    249			return -EIO;
    250		}
    251	  	dev->r_buf[i] = xinb(iobase + REG_OFFSET_BULK_IN);
    252#ifdef CM4040_DEBUG
    253		pr_debug("%lu:%2x ", i, dev->r_buf[i]);
    254	}
    255	pr_debug("\n");
    256#else
    257	}
    258#endif
    259
    260	bytes_to_read = 5 + le32_to_cpu(*(__le32 *)&dev->r_buf[1]);
    261
    262	DEBUGP(6, dev, "BytesToRead=%zu\n", bytes_to_read);
    263
    264	min_bytes_to_read = min(count, bytes_to_read + 5);
    265	min_bytes_to_read = min_t(size_t, min_bytes_to_read, READ_WRITE_BUFFER_SIZE);
    266
    267	DEBUGP(6, dev, "Min=%zu\n", min_bytes_to_read);
    268
    269	for (i = 0; i < (min_bytes_to_read-5); i++) {
    270		rc = wait_for_bulk_in_ready(dev);
    271		if (rc <= 0) {
    272			DEBUGP(5, dev, "wait_for_bulk_in_ready rc=%.2x\n", rc);
    273			DEBUGP(2, dev, "<- cm4040_read (failed)\n");
    274			if (rc == -ERESTARTSYS)
    275				return rc;
    276			return -EIO;
    277		}
    278		dev->r_buf[i+5] = xinb(iobase + REG_OFFSET_BULK_IN);
    279#ifdef CM4040_DEBUG
    280		pr_debug("%lu:%2x ", i, dev->r_buf[i]);
    281	}
    282	pr_debug("\n");
    283#else
    284	}
    285#endif
    286
    287	*ppos = min_bytes_to_read;
    288	if (copy_to_user(buf, dev->r_buf, min_bytes_to_read))
    289		return -EFAULT;
    290
    291	rc = wait_for_bulk_in_ready(dev);
    292	if (rc <= 0) {
    293		DEBUGP(5, dev, "wait_for_bulk_in_ready rc=%.2x\n", rc);
    294		DEBUGP(2, dev, "<- cm4040_read (failed)\n");
    295		if (rc == -ERESTARTSYS)
    296			return rc;
    297		return -EIO;
    298	}
    299
    300	rc = write_sync_reg(SCR_READER_TO_HOST_DONE, dev);
    301	if (rc <= 0) {
    302		DEBUGP(5, dev, "write_sync_reg c=%.2x\n", rc);
    303		DEBUGP(2, dev, "<- cm4040_read (failed)\n");
    304		if (rc == -ERESTARTSYS)
    305			return rc;
    306		else
    307			return -EIO;
    308	}
    309
    310	xinb(iobase + REG_OFFSET_BULK_IN);
    311
    312	DEBUGP(2, dev, "<- cm4040_read (successfully)\n");
    313	return min_bytes_to_read;
    314}
    315
    316static ssize_t cm4040_write(struct file *filp, const char __user *buf,
    317			 size_t count, loff_t *ppos)
    318{
    319	struct reader_dev *dev = filp->private_data;
    320	int iobase = dev->p_dev->resource[0]->start;
    321	ssize_t rc;
    322	int i;
    323	unsigned int bytes_to_write;
    324
    325	DEBUGP(2, dev, "-> cm4040_write(%s,%d)\n", current->comm, current->pid);
    326
    327	if (count == 0) {
    328		DEBUGP(2, dev, "<- cm4040_write empty read (successfully)\n");
    329		return 0;
    330	}
    331
    332	if ((count < 5) || (count > READ_WRITE_BUFFER_SIZE)) {
    333		DEBUGP(2, dev, "<- cm4040_write buffersize=%zd < 5\n", count);
    334		return -EIO;
    335	}
    336
    337	if (filp->f_flags & O_NONBLOCK) {
    338		DEBUGP(4, dev, "filep->f_flags O_NONBLOCK set\n");
    339		DEBUGP(4, dev, "<- cm4040_write (failure)\n");
    340		return -EAGAIN;
    341	}
    342
    343	if (!pcmcia_dev_present(dev->p_dev))
    344		return -ENODEV;
    345
    346	bytes_to_write = count;
    347	if (copy_from_user(dev->s_buf, buf, bytes_to_write))
    348		return -EFAULT;
    349
    350	switch (dev->s_buf[0]) {
    351		case CMD_PC_TO_RDR_XFRBLOCK:
    352		case CMD_PC_TO_RDR_SECURE:
    353		case CMD_PC_TO_RDR_TEST_SECURE:
    354		case CMD_PC_TO_RDR_OK_SECURE:
    355			dev->timeout = CCID_DRIVER_BULK_DEFAULT_TIMEOUT;
    356			break;
    357
    358		case CMD_PC_TO_RDR_ICCPOWERON:
    359			dev->timeout = CCID_DRIVER_ASYNC_POWERUP_TIMEOUT;
    360			break;
    361
    362		case CMD_PC_TO_RDR_GETSLOTSTATUS:
    363		case CMD_PC_TO_RDR_ICCPOWEROFF:
    364		case CMD_PC_TO_RDR_GETPARAMETERS:
    365		case CMD_PC_TO_RDR_RESETPARAMETERS:
    366		case CMD_PC_TO_RDR_SETPARAMETERS:
    367		case CMD_PC_TO_RDR_ESCAPE:
    368		case CMD_PC_TO_RDR_ICCCLOCK:
    369		default:
    370			dev->timeout = CCID_DRIVER_MINIMUM_TIMEOUT;
    371			break;
    372	}
    373
    374	rc = write_sync_reg(SCR_HOST_TO_READER_START, dev);
    375	if (rc <= 0) {
    376		DEBUGP(5, dev, "write_sync_reg c=%.2zx\n", rc);
    377		DEBUGP(2, dev, "<- cm4040_write (failed)\n");
    378		if (rc == -ERESTARTSYS)
    379			return rc;
    380		else
    381			return -EIO;
    382	}
    383
    384	DEBUGP(4, dev, "start \n");
    385
    386	for (i = 0; i < bytes_to_write; i++) {
    387		rc = wait_for_bulk_out_ready(dev);
    388		if (rc <= 0) {
    389			DEBUGP(5, dev, "wait_for_bulk_out_ready rc=%.2zx\n",
    390			       rc);
    391			DEBUGP(2, dev, "<- cm4040_write (failed)\n");
    392			if (rc == -ERESTARTSYS)
    393				return rc;
    394			else
    395				return -EIO;
    396		}
    397
    398		xoutb(dev->s_buf[i],iobase + REG_OFFSET_BULK_OUT);
    399	}
    400	DEBUGP(4, dev, "end\n");
    401
    402	rc = write_sync_reg(SCR_HOST_TO_READER_DONE, dev);
    403
    404	if (rc <= 0) {
    405		DEBUGP(5, dev, "write_sync_reg c=%.2zx\n", rc);
    406		DEBUGP(2, dev, "<- cm4040_write (failed)\n");
    407		if (rc == -ERESTARTSYS)
    408			return rc;
    409		else
    410			return -EIO;
    411	}
    412
    413	DEBUGP(2, dev, "<- cm4040_write (successfully)\n");
    414	return count;
    415}
    416
    417static __poll_t cm4040_poll(struct file *filp, poll_table *wait)
    418{
    419	struct reader_dev *dev = filp->private_data;
    420	__poll_t mask = 0;
    421
    422	poll_wait(filp, &dev->poll_wait, wait);
    423
    424	if (test_and_clear_bit(BS_READABLE, &dev->buffer_status))
    425		mask |= EPOLLIN | EPOLLRDNORM;
    426	if (test_and_clear_bit(BS_WRITABLE, &dev->buffer_status))
    427		mask |= EPOLLOUT | EPOLLWRNORM;
    428
    429	DEBUGP(2, dev, "<- cm4040_poll(%u)\n", mask);
    430
    431	return mask;
    432}
    433
    434static int cm4040_open(struct inode *inode, struct file *filp)
    435{
    436	struct reader_dev *dev;
    437	struct pcmcia_device *link;
    438	int minor = iminor(inode);
    439	int ret;
    440
    441	if (minor >= CM_MAX_DEV)
    442		return -ENODEV;
    443
    444	mutex_lock(&cm4040_mutex);
    445	link = dev_table[minor];
    446	if (link == NULL || !pcmcia_dev_present(link)) {
    447		ret = -ENODEV;
    448		goto out;
    449	}
    450
    451	if (link->open) {
    452		ret = -EBUSY;
    453		goto out;
    454	}
    455
    456	dev = link->priv;
    457	filp->private_data = dev;
    458
    459	if (filp->f_flags & O_NONBLOCK) {
    460		DEBUGP(4, dev, "filep->f_flags O_NONBLOCK set\n");
    461		ret = -EAGAIN;
    462		goto out;
    463	}
    464
    465	link->open = 1;
    466
    467	mod_timer(&dev->poll_timer, jiffies + POLL_PERIOD);
    468
    469	DEBUGP(2, dev, "<- cm4040_open (successfully)\n");
    470	ret = nonseekable_open(inode, filp);
    471out:
    472	mutex_unlock(&cm4040_mutex);
    473	return ret;
    474}
    475
    476static int cm4040_close(struct inode *inode, struct file *filp)
    477{
    478	struct reader_dev *dev = filp->private_data;
    479	struct pcmcia_device *link;
    480	int minor = iminor(inode);
    481
    482	DEBUGP(2, dev, "-> cm4040_close(maj/min=%d.%d)\n", imajor(inode),
    483	      iminor(inode));
    484
    485	if (minor >= CM_MAX_DEV)
    486		return -ENODEV;
    487
    488	link = dev_table[minor];
    489	if (link == NULL)
    490		return -ENODEV;
    491
    492	cm4040_stop_poll(dev);
    493
    494	link->open = 0;
    495	wake_up(&dev->devq);
    496
    497	DEBUGP(2, dev, "<- cm4040_close\n");
    498	return 0;
    499}
    500
    501static void cm4040_reader_release(struct pcmcia_device *link)
    502{
    503	struct reader_dev *dev = link->priv;
    504
    505	DEBUGP(3, dev, "-> cm4040_reader_release\n");
    506	while (link->open) {
    507		DEBUGP(3, dev, MODULE_NAME ": delaying release "
    508		       "until process has terminated\n");
    509 		wait_event(dev->devq, (link->open == 0));
    510	}
    511	DEBUGP(3, dev, "<- cm4040_reader_release\n");
    512	return;
    513}
    514
    515static int cm4040_config_check(struct pcmcia_device *p_dev, void *priv_data)
    516{
    517	return pcmcia_request_io(p_dev);
    518}
    519
    520
    521static int reader_config(struct pcmcia_device *link, int devno)
    522{
    523	struct reader_dev *dev;
    524	int fail_rc;
    525
    526	link->config_flags |= CONF_AUTO_SET_IO;
    527
    528	if (pcmcia_loop_config(link, cm4040_config_check, NULL))
    529		goto cs_release;
    530
    531	fail_rc = pcmcia_enable_device(link);
    532	if (fail_rc != 0) {
    533		dev_info(&link->dev, "pcmcia_enable_device failed 0x%x\n",
    534			 fail_rc);
    535		goto cs_release;
    536	}
    537
    538	dev = link->priv;
    539
    540	DEBUGP(2, dev, "device " DEVICE_NAME "%d at %pR\n", devno,
    541	      link->resource[0]);
    542	DEBUGP(2, dev, "<- reader_config (succ)\n");
    543
    544	return 0;
    545
    546cs_release:
    547	reader_release(link);
    548	return -ENODEV;
    549}
    550
    551static void reader_release(struct pcmcia_device *link)
    552{
    553	cm4040_reader_release(link);
    554	pcmcia_disable_device(link);
    555}
    556
    557static int reader_probe(struct pcmcia_device *link)
    558{
    559	struct reader_dev *dev;
    560	int i, ret;
    561
    562	for (i = 0; i < CM_MAX_DEV; i++) {
    563		if (dev_table[i] == NULL)
    564			break;
    565	}
    566
    567	if (i == CM_MAX_DEV)
    568		return -ENODEV;
    569
    570	dev = kzalloc(sizeof(struct reader_dev), GFP_KERNEL);
    571	if (dev == NULL)
    572		return -ENOMEM;
    573
    574	dev->timeout = CCID_DRIVER_MINIMUM_TIMEOUT;
    575	dev->buffer_status = 0;
    576
    577	link->priv = dev;
    578	dev->p_dev = link;
    579
    580	dev_table[i] = link;
    581
    582	init_waitqueue_head(&dev->devq);
    583	init_waitqueue_head(&dev->poll_wait);
    584	init_waitqueue_head(&dev->read_wait);
    585	init_waitqueue_head(&dev->write_wait);
    586	timer_setup(&dev->poll_timer, cm4040_do_poll, 0);
    587
    588	ret = reader_config(link, i);
    589	if (ret) {
    590		dev_table[i] = NULL;
    591		kfree(dev);
    592		return ret;
    593	}
    594
    595	device_create(cmx_class, NULL, MKDEV(major, i), NULL, "cmx%d", i);
    596
    597	return 0;
    598}
    599
    600static void reader_detach(struct pcmcia_device *link)
    601{
    602	struct reader_dev *dev = link->priv;
    603	int devno;
    604
    605	/* find device */
    606	for (devno = 0; devno < CM_MAX_DEV; devno++) {
    607		if (dev_table[devno] == link)
    608			break;
    609	}
    610	if (devno == CM_MAX_DEV)
    611		return;
    612
    613	reader_release(link);
    614
    615	dev_table[devno] = NULL;
    616	kfree(dev);
    617
    618	device_destroy(cmx_class, MKDEV(major, devno));
    619
    620	return;
    621}
    622
    623static const struct file_operations reader_fops = {
    624	.owner		= THIS_MODULE,
    625	.read		= cm4040_read,
    626	.write		= cm4040_write,
    627	.open		= cm4040_open,
    628	.release	= cm4040_close,
    629	.poll		= cm4040_poll,
    630	.llseek		= no_llseek,
    631};
    632
    633static const struct pcmcia_device_id cm4040_ids[] = {
    634	PCMCIA_DEVICE_MANF_CARD(0x0223, 0x0200),
    635	PCMCIA_DEVICE_PROD_ID12("OMNIKEY", "CardMan 4040",
    636				0xE32CDD8C, 0x8F23318B),
    637	PCMCIA_DEVICE_NULL,
    638};
    639MODULE_DEVICE_TABLE(pcmcia, cm4040_ids);
    640
    641static struct pcmcia_driver reader_driver = {
    642  	.owner		= THIS_MODULE,
    643	.name		= "cm4040_cs",
    644	.probe		= reader_probe,
    645	.remove		= reader_detach,
    646	.id_table	= cm4040_ids,
    647};
    648
    649static int __init cm4040_init(void)
    650{
    651	int rc;
    652
    653	cmx_class = class_create(THIS_MODULE, "cardman_4040");
    654	if (IS_ERR(cmx_class))
    655		return PTR_ERR(cmx_class);
    656
    657	major = register_chrdev(0, DEVICE_NAME, &reader_fops);
    658	if (major < 0) {
    659		printk(KERN_WARNING MODULE_NAME
    660			": could not get major number\n");
    661		class_destroy(cmx_class);
    662		return major;
    663	}
    664
    665	rc = pcmcia_register_driver(&reader_driver);
    666	if (rc < 0) {
    667		unregister_chrdev(major, DEVICE_NAME);
    668		class_destroy(cmx_class);
    669		return rc;
    670	}
    671
    672	return 0;
    673}
    674
    675static void __exit cm4040_exit(void)
    676{
    677	pcmcia_unregister_driver(&reader_driver);
    678	unregister_chrdev(major, DEVICE_NAME);
    679	class_destroy(cmx_class);
    680}
    681
    682module_init(cm4040_init);
    683module_exit(cm4040_exit);
    684MODULE_LICENSE("Dual BSD/GPL");