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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/char/pcmcia/cm4040_cs.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/char/pcmcia/cm4040_cs.c')
-rw-r--r--drivers/char/pcmcia/cm4040_cs.c684
1 files changed, 684 insertions, 0 deletions
diff --git a/drivers/char/pcmcia/cm4040_cs.c b/drivers/char/pcmcia/cm4040_cs.c
new file mode 100644
index 000000000..827711911
--- /dev/null
+++ b/drivers/char/pcmcia/cm4040_cs.c
@@ -0,0 +1,684 @@
+/*
+ * A driver for the Omnikey PCMCIA smartcard reader CardMan 4040
+ *
+ * (c) 2000-2004 Omnikey AG (http://www.omnikey.com/)
+ *
+ * (C) 2005-2006 Harald Welte <laforge@gnumonks.org>
+ * - add support for poll()
+ * - driver cleanup
+ * - add waitqueues
+ * - adhere to linux kernel coding style and policies
+ * - support 2.6.13 "new style" pcmcia interface
+ * - add class interface for udev device creation
+ *
+ * The device basically is a USB CCID compliant device that has been
+ * attached to an I/O-Mapped FIFO.
+ *
+ * All rights reserved, Dual BSD/GPL Licensed.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/delay.h>
+#include <linux/poll.h>
+#include <linux/mutex.h>
+#include <linux/wait.h>
+#include <linux/uaccess.h>
+#include <asm/io.h>
+
+#include <pcmcia/cistpl.h>
+#include <pcmcia/cisreg.h>
+#include <pcmcia/ciscode.h>
+#include <pcmcia/ds.h>
+
+#include "cm4040_cs.h"
+
+
+#define reader_to_dev(x) (&x->p_dev->dev)
+
+/* n (debug level) is ignored */
+/* additional debug output may be enabled by re-compiling with
+ * CM4040_DEBUG set */
+/* #define CM4040_DEBUG */
+#define DEBUGP(n, rdr, x, args...) do { \
+ dev_dbg(reader_to_dev(rdr), "%s:" x, \
+ __func__ , ## args); \
+ } while (0)
+
+static DEFINE_MUTEX(cm4040_mutex);
+
+#define CCID_DRIVER_BULK_DEFAULT_TIMEOUT (150*HZ)
+#define CCID_DRIVER_ASYNC_POWERUP_TIMEOUT (35*HZ)
+#define CCID_DRIVER_MINIMUM_TIMEOUT (3*HZ)
+#define READ_WRITE_BUFFER_SIZE 512
+#define POLL_LOOP_COUNT 1000
+
+/* how often to poll for fifo status change */
+#define POLL_PERIOD msecs_to_jiffies(10)
+
+static void reader_release(struct pcmcia_device *link);
+
+static int major;
+static struct class *cmx_class;
+
+#define BS_READABLE 0x01
+#define BS_WRITABLE 0x02
+
+struct reader_dev {
+ struct pcmcia_device *p_dev;
+ wait_queue_head_t devq;
+ wait_queue_head_t poll_wait;
+ wait_queue_head_t read_wait;
+ wait_queue_head_t write_wait;
+ unsigned long buffer_status;
+ unsigned long timeout;
+ unsigned char s_buf[READ_WRITE_BUFFER_SIZE];
+ unsigned char r_buf[READ_WRITE_BUFFER_SIZE];
+ struct timer_list poll_timer;
+};
+
+static struct pcmcia_device *dev_table[CM_MAX_DEV];
+
+#ifndef CM4040_DEBUG
+#define xoutb outb
+#define xinb inb
+#else
+static inline void xoutb(unsigned char val, unsigned short port)
+{
+ pr_debug("outb(val=%.2x,port=%.4x)\n", val, port);
+ outb(val, port);
+}
+
+static inline unsigned char xinb(unsigned short port)
+{
+ unsigned char val;
+
+ val = inb(port);
+ pr_debug("%.2x=inb(%.4x)\n", val, port);
+ return val;
+}
+#endif
+
+/* poll the device fifo status register. not to be confused with
+ * the poll syscall. */
+static void cm4040_do_poll(struct timer_list *t)
+{
+ struct reader_dev *dev = from_timer(dev, t, poll_timer);
+ unsigned int obs = xinb(dev->p_dev->resource[0]->start
+ + REG_OFFSET_BUFFER_STATUS);
+
+ if ((obs & BSR_BULK_IN_FULL)) {
+ set_bit(BS_READABLE, &dev->buffer_status);
+ DEBUGP(4, dev, "waking up read_wait\n");
+ wake_up_interruptible(&dev->read_wait);
+ } else
+ clear_bit(BS_READABLE, &dev->buffer_status);
+
+ if (!(obs & BSR_BULK_OUT_FULL)) {
+ set_bit(BS_WRITABLE, &dev->buffer_status);
+ DEBUGP(4, dev, "waking up write_wait\n");
+ wake_up_interruptible(&dev->write_wait);
+ } else
+ clear_bit(BS_WRITABLE, &dev->buffer_status);
+
+ if (dev->buffer_status)
+ wake_up_interruptible(&dev->poll_wait);
+
+ mod_timer(&dev->poll_timer, jiffies + POLL_PERIOD);
+}
+
+static void cm4040_stop_poll(struct reader_dev *dev)
+{
+ del_timer_sync(&dev->poll_timer);
+}
+
+static int wait_for_bulk_out_ready(struct reader_dev *dev)
+{
+ int i, rc;
+ int iobase = dev->p_dev->resource[0]->start;
+
+ for (i = 0; i < POLL_LOOP_COUNT; i++) {
+ if ((xinb(iobase + REG_OFFSET_BUFFER_STATUS)
+ & BSR_BULK_OUT_FULL) == 0) {
+ DEBUGP(4, dev, "BulkOut empty (i=%d)\n", i);
+ return 1;
+ }
+ }
+
+ DEBUGP(4, dev, "wait_event_interruptible_timeout(timeout=%ld\n",
+ dev->timeout);
+ rc = wait_event_interruptible_timeout(dev->write_wait,
+ test_and_clear_bit(BS_WRITABLE,
+ &dev->buffer_status),
+ dev->timeout);
+
+ if (rc > 0)
+ DEBUGP(4, dev, "woke up: BulkOut empty\n");
+ else if (rc == 0)
+ DEBUGP(4, dev, "woke up: BulkOut full, returning 0 :(\n");
+ else if (rc < 0)
+ DEBUGP(4, dev, "woke up: signal arrived\n");
+
+ return rc;
+}
+
+/* Write to Sync Control Register */
+static int write_sync_reg(unsigned char val, struct reader_dev *dev)
+{
+ int iobase = dev->p_dev->resource[0]->start;
+ int rc;
+
+ rc = wait_for_bulk_out_ready(dev);
+ if (rc <= 0)
+ return rc;
+
+ xoutb(val, iobase + REG_OFFSET_SYNC_CONTROL);
+ rc = wait_for_bulk_out_ready(dev);
+ if (rc <= 0)
+ return rc;
+
+ return 1;
+}
+
+static int wait_for_bulk_in_ready(struct reader_dev *dev)
+{
+ int i, rc;
+ int iobase = dev->p_dev->resource[0]->start;
+
+ for (i = 0; i < POLL_LOOP_COUNT; i++) {
+ if ((xinb(iobase + REG_OFFSET_BUFFER_STATUS)
+ & BSR_BULK_IN_FULL) == BSR_BULK_IN_FULL) {
+ DEBUGP(3, dev, "BulkIn full (i=%d)\n", i);
+ return 1;
+ }
+ }
+
+ DEBUGP(4, dev, "wait_event_interruptible_timeout(timeout=%ld\n",
+ dev->timeout);
+ rc = wait_event_interruptible_timeout(dev->read_wait,
+ test_and_clear_bit(BS_READABLE,
+ &dev->buffer_status),
+ dev->timeout);
+ if (rc > 0)
+ DEBUGP(4, dev, "woke up: BulkIn full\n");
+ else if (rc == 0)
+ DEBUGP(4, dev, "woke up: BulkIn not full, returning 0 :(\n");
+ else if (rc < 0)
+ DEBUGP(4, dev, "woke up: signal arrived\n");
+
+ return rc;
+}
+
+static ssize_t cm4040_read(struct file *filp, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct reader_dev *dev = filp->private_data;
+ int iobase = dev->p_dev->resource[0]->start;
+ size_t bytes_to_read;
+ unsigned long i;
+ size_t min_bytes_to_read;
+ int rc;
+
+ DEBUGP(2, dev, "-> cm4040_read(%s,%d)\n", current->comm, current->pid);
+
+ if (count == 0)
+ return 0;
+
+ if (count < 10)
+ return -EFAULT;
+
+ if (filp->f_flags & O_NONBLOCK) {
+ DEBUGP(4, dev, "filep->f_flags O_NONBLOCK set\n");
+ DEBUGP(2, dev, "<- cm4040_read (failure)\n");
+ return -EAGAIN;
+ }
+
+ if (!pcmcia_dev_present(dev->p_dev))
+ return -ENODEV;
+
+ for (i = 0; i < 5; i++) {
+ rc = wait_for_bulk_in_ready(dev);
+ if (rc <= 0) {
+ DEBUGP(5, dev, "wait_for_bulk_in_ready rc=%.2x\n", rc);
+ DEBUGP(2, dev, "<- cm4040_read (failed)\n");
+ if (rc == -ERESTARTSYS)
+ return rc;
+ return -EIO;
+ }
+ dev->r_buf[i] = xinb(iobase + REG_OFFSET_BULK_IN);
+#ifdef CM4040_DEBUG
+ pr_debug("%lu:%2x ", i, dev->r_buf[i]);
+ }
+ pr_debug("\n");
+#else
+ }
+#endif
+
+ bytes_to_read = 5 + le32_to_cpu(*(__le32 *)&dev->r_buf[1]);
+
+ DEBUGP(6, dev, "BytesToRead=%zu\n", bytes_to_read);
+
+ min_bytes_to_read = min(count, bytes_to_read + 5);
+ min_bytes_to_read = min_t(size_t, min_bytes_to_read, READ_WRITE_BUFFER_SIZE);
+
+ DEBUGP(6, dev, "Min=%zu\n", min_bytes_to_read);
+
+ for (i = 0; i < (min_bytes_to_read-5); i++) {
+ rc = wait_for_bulk_in_ready(dev);
+ if (rc <= 0) {
+ DEBUGP(5, dev, "wait_for_bulk_in_ready rc=%.2x\n", rc);
+ DEBUGP(2, dev, "<- cm4040_read (failed)\n");
+ if (rc == -ERESTARTSYS)
+ return rc;
+ return -EIO;
+ }
+ dev->r_buf[i+5] = xinb(iobase + REG_OFFSET_BULK_IN);
+#ifdef CM4040_DEBUG
+ pr_debug("%lu:%2x ", i, dev->r_buf[i]);
+ }
+ pr_debug("\n");
+#else
+ }
+#endif
+
+ *ppos = min_bytes_to_read;
+ if (copy_to_user(buf, dev->r_buf, min_bytes_to_read))
+ return -EFAULT;
+
+ rc = wait_for_bulk_in_ready(dev);
+ if (rc <= 0) {
+ DEBUGP(5, dev, "wait_for_bulk_in_ready rc=%.2x\n", rc);
+ DEBUGP(2, dev, "<- cm4040_read (failed)\n");
+ if (rc == -ERESTARTSYS)
+ return rc;
+ return -EIO;
+ }
+
+ rc = write_sync_reg(SCR_READER_TO_HOST_DONE, dev);
+ if (rc <= 0) {
+ DEBUGP(5, dev, "write_sync_reg c=%.2x\n", rc);
+ DEBUGP(2, dev, "<- cm4040_read (failed)\n");
+ if (rc == -ERESTARTSYS)
+ return rc;
+ else
+ return -EIO;
+ }
+
+ xinb(iobase + REG_OFFSET_BULK_IN);
+
+ DEBUGP(2, dev, "<- cm4040_read (successfully)\n");
+ return min_bytes_to_read;
+}
+
+static ssize_t cm4040_write(struct file *filp, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct reader_dev *dev = filp->private_data;
+ int iobase = dev->p_dev->resource[0]->start;
+ ssize_t rc;
+ int i;
+ unsigned int bytes_to_write;
+
+ DEBUGP(2, dev, "-> cm4040_write(%s,%d)\n", current->comm, current->pid);
+
+ if (count == 0) {
+ DEBUGP(2, dev, "<- cm4040_write empty read (successfully)\n");
+ return 0;
+ }
+
+ if ((count < 5) || (count > READ_WRITE_BUFFER_SIZE)) {
+ DEBUGP(2, dev, "<- cm4040_write buffersize=%zd < 5\n", count);
+ return -EIO;
+ }
+
+ if (filp->f_flags & O_NONBLOCK) {
+ DEBUGP(4, dev, "filep->f_flags O_NONBLOCK set\n");
+ DEBUGP(4, dev, "<- cm4040_write (failure)\n");
+ return -EAGAIN;
+ }
+
+ if (!pcmcia_dev_present(dev->p_dev))
+ return -ENODEV;
+
+ bytes_to_write = count;
+ if (copy_from_user(dev->s_buf, buf, bytes_to_write))
+ return -EFAULT;
+
+ switch (dev->s_buf[0]) {
+ case CMD_PC_TO_RDR_XFRBLOCK:
+ case CMD_PC_TO_RDR_SECURE:
+ case CMD_PC_TO_RDR_TEST_SECURE:
+ case CMD_PC_TO_RDR_OK_SECURE:
+ dev->timeout = CCID_DRIVER_BULK_DEFAULT_TIMEOUT;
+ break;
+
+ case CMD_PC_TO_RDR_ICCPOWERON:
+ dev->timeout = CCID_DRIVER_ASYNC_POWERUP_TIMEOUT;
+ break;
+
+ case CMD_PC_TO_RDR_GETSLOTSTATUS:
+ case CMD_PC_TO_RDR_ICCPOWEROFF:
+ case CMD_PC_TO_RDR_GETPARAMETERS:
+ case CMD_PC_TO_RDR_RESETPARAMETERS:
+ case CMD_PC_TO_RDR_SETPARAMETERS:
+ case CMD_PC_TO_RDR_ESCAPE:
+ case CMD_PC_TO_RDR_ICCCLOCK:
+ default:
+ dev->timeout = CCID_DRIVER_MINIMUM_TIMEOUT;
+ break;
+ }
+
+ rc = write_sync_reg(SCR_HOST_TO_READER_START, dev);
+ if (rc <= 0) {
+ DEBUGP(5, dev, "write_sync_reg c=%.2zx\n", rc);
+ DEBUGP(2, dev, "<- cm4040_write (failed)\n");
+ if (rc == -ERESTARTSYS)
+ return rc;
+ else
+ return -EIO;
+ }
+
+ DEBUGP(4, dev, "start \n");
+
+ for (i = 0; i < bytes_to_write; i++) {
+ rc = wait_for_bulk_out_ready(dev);
+ if (rc <= 0) {
+ DEBUGP(5, dev, "wait_for_bulk_out_ready rc=%.2zx\n",
+ rc);
+ DEBUGP(2, dev, "<- cm4040_write (failed)\n");
+ if (rc == -ERESTARTSYS)
+ return rc;
+ else
+ return -EIO;
+ }
+
+ xoutb(dev->s_buf[i],iobase + REG_OFFSET_BULK_OUT);
+ }
+ DEBUGP(4, dev, "end\n");
+
+ rc = write_sync_reg(SCR_HOST_TO_READER_DONE, dev);
+
+ if (rc <= 0) {
+ DEBUGP(5, dev, "write_sync_reg c=%.2zx\n", rc);
+ DEBUGP(2, dev, "<- cm4040_write (failed)\n");
+ if (rc == -ERESTARTSYS)
+ return rc;
+ else
+ return -EIO;
+ }
+
+ DEBUGP(2, dev, "<- cm4040_write (successfully)\n");
+ return count;
+}
+
+static __poll_t cm4040_poll(struct file *filp, poll_table *wait)
+{
+ struct reader_dev *dev = filp->private_data;
+ __poll_t mask = 0;
+
+ poll_wait(filp, &dev->poll_wait, wait);
+
+ if (test_and_clear_bit(BS_READABLE, &dev->buffer_status))
+ mask |= EPOLLIN | EPOLLRDNORM;
+ if (test_and_clear_bit(BS_WRITABLE, &dev->buffer_status))
+ mask |= EPOLLOUT | EPOLLWRNORM;
+
+ DEBUGP(2, dev, "<- cm4040_poll(%u)\n", mask);
+
+ return mask;
+}
+
+static int cm4040_open(struct inode *inode, struct file *filp)
+{
+ struct reader_dev *dev;
+ struct pcmcia_device *link;
+ int minor = iminor(inode);
+ int ret;
+
+ if (minor >= CM_MAX_DEV)
+ return -ENODEV;
+
+ mutex_lock(&cm4040_mutex);
+ link = dev_table[minor];
+ if (link == NULL || !pcmcia_dev_present(link)) {
+ ret = -ENODEV;
+ goto out;
+ }
+
+ if (link->open) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ dev = link->priv;
+ filp->private_data = dev;
+
+ if (filp->f_flags & O_NONBLOCK) {
+ DEBUGP(4, dev, "filep->f_flags O_NONBLOCK set\n");
+ ret = -EAGAIN;
+ goto out;
+ }
+
+ link->open = 1;
+
+ mod_timer(&dev->poll_timer, jiffies + POLL_PERIOD);
+
+ DEBUGP(2, dev, "<- cm4040_open (successfully)\n");
+ ret = nonseekable_open(inode, filp);
+out:
+ mutex_unlock(&cm4040_mutex);
+ return ret;
+}
+
+static int cm4040_close(struct inode *inode, struct file *filp)
+{
+ struct reader_dev *dev = filp->private_data;
+ struct pcmcia_device *link;
+ int minor = iminor(inode);
+
+ DEBUGP(2, dev, "-> cm4040_close(maj/min=%d.%d)\n", imajor(inode),
+ iminor(inode));
+
+ if (minor >= CM_MAX_DEV)
+ return -ENODEV;
+
+ link = dev_table[minor];
+ if (link == NULL)
+ return -ENODEV;
+
+ cm4040_stop_poll(dev);
+
+ link->open = 0;
+ wake_up(&dev->devq);
+
+ DEBUGP(2, dev, "<- cm4040_close\n");
+ return 0;
+}
+
+static void cm4040_reader_release(struct pcmcia_device *link)
+{
+ struct reader_dev *dev = link->priv;
+
+ DEBUGP(3, dev, "-> cm4040_reader_release\n");
+ while (link->open) {
+ DEBUGP(3, dev, MODULE_NAME ": delaying release "
+ "until process has terminated\n");
+ wait_event(dev->devq, (link->open == 0));
+ }
+ DEBUGP(3, dev, "<- cm4040_reader_release\n");
+ return;
+}
+
+static int cm4040_config_check(struct pcmcia_device *p_dev, void *priv_data)
+{
+ return pcmcia_request_io(p_dev);
+}
+
+
+static int reader_config(struct pcmcia_device *link, int devno)
+{
+ struct reader_dev *dev;
+ int fail_rc;
+
+ link->config_flags |= CONF_AUTO_SET_IO;
+
+ if (pcmcia_loop_config(link, cm4040_config_check, NULL))
+ goto cs_release;
+
+ fail_rc = pcmcia_enable_device(link);
+ if (fail_rc != 0) {
+ dev_info(&link->dev, "pcmcia_enable_device failed 0x%x\n",
+ fail_rc);
+ goto cs_release;
+ }
+
+ dev = link->priv;
+
+ DEBUGP(2, dev, "device " DEVICE_NAME "%d at %pR\n", devno,
+ link->resource[0]);
+ DEBUGP(2, dev, "<- reader_config (succ)\n");
+
+ return 0;
+
+cs_release:
+ reader_release(link);
+ return -ENODEV;
+}
+
+static void reader_release(struct pcmcia_device *link)
+{
+ cm4040_reader_release(link);
+ pcmcia_disable_device(link);
+}
+
+static int reader_probe(struct pcmcia_device *link)
+{
+ struct reader_dev *dev;
+ int i, ret;
+
+ for (i = 0; i < CM_MAX_DEV; i++) {
+ if (dev_table[i] == NULL)
+ break;
+ }
+
+ if (i == CM_MAX_DEV)
+ return -ENODEV;
+
+ dev = kzalloc(sizeof(struct reader_dev), GFP_KERNEL);
+ if (dev == NULL)
+ return -ENOMEM;
+
+ dev->timeout = CCID_DRIVER_MINIMUM_TIMEOUT;
+ dev->buffer_status = 0;
+
+ link->priv = dev;
+ dev->p_dev = link;
+
+ dev_table[i] = link;
+
+ init_waitqueue_head(&dev->devq);
+ init_waitqueue_head(&dev->poll_wait);
+ init_waitqueue_head(&dev->read_wait);
+ init_waitqueue_head(&dev->write_wait);
+ timer_setup(&dev->poll_timer, cm4040_do_poll, 0);
+
+ ret = reader_config(link, i);
+ if (ret) {
+ dev_table[i] = NULL;
+ kfree(dev);
+ return ret;
+ }
+
+ device_create(cmx_class, NULL, MKDEV(major, i), NULL, "cmx%d", i);
+
+ return 0;
+}
+
+static void reader_detach(struct pcmcia_device *link)
+{
+ struct reader_dev *dev = link->priv;
+ int devno;
+
+ /* find device */
+ for (devno = 0; devno < CM_MAX_DEV; devno++) {
+ if (dev_table[devno] == link)
+ break;
+ }
+ if (devno == CM_MAX_DEV)
+ return;
+
+ reader_release(link);
+
+ dev_table[devno] = NULL;
+ kfree(dev);
+
+ device_destroy(cmx_class, MKDEV(major, devno));
+
+ return;
+}
+
+static const struct file_operations reader_fops = {
+ .owner = THIS_MODULE,
+ .read = cm4040_read,
+ .write = cm4040_write,
+ .open = cm4040_open,
+ .release = cm4040_close,
+ .poll = cm4040_poll,
+ .llseek = no_llseek,
+};
+
+static const struct pcmcia_device_id cm4040_ids[] = {
+ PCMCIA_DEVICE_MANF_CARD(0x0223, 0x0200),
+ PCMCIA_DEVICE_PROD_ID12("OMNIKEY", "CardMan 4040",
+ 0xE32CDD8C, 0x8F23318B),
+ PCMCIA_DEVICE_NULL,
+};
+MODULE_DEVICE_TABLE(pcmcia, cm4040_ids);
+
+static struct pcmcia_driver reader_driver = {
+ .owner = THIS_MODULE,
+ .name = "cm4040_cs",
+ .probe = reader_probe,
+ .remove = reader_detach,
+ .id_table = cm4040_ids,
+};
+
+static int __init cm4040_init(void)
+{
+ int rc;
+
+ cmx_class = class_create(THIS_MODULE, "cardman_4040");
+ if (IS_ERR(cmx_class))
+ return PTR_ERR(cmx_class);
+
+ major = register_chrdev(0, DEVICE_NAME, &reader_fops);
+ if (major < 0) {
+ printk(KERN_WARNING MODULE_NAME
+ ": could not get major number\n");
+ class_destroy(cmx_class);
+ return major;
+ }
+
+ rc = pcmcia_register_driver(&reader_driver);
+ if (rc < 0) {
+ unregister_chrdev(major, DEVICE_NAME);
+ class_destroy(cmx_class);
+ return rc;
+ }
+
+ return 0;
+}
+
+static void __exit cm4040_exit(void)
+{
+ pcmcia_unregister_driver(&reader_driver);
+ unregister_chrdev(major, DEVICE_NAME);
+ class_destroy(cmx_class);
+}
+
+module_init(cm4040_init);
+module_exit(cm4040_exit);
+MODULE_LICENSE("Dual BSD/GPL");