cm4040_cs.c

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/*
 * A driver for the Omnikey PCMCIA smartcard reader CardMan 4040
 *
 * (c) 2000-2004 Omnikey AG (http://www.omnikey.com/)
 *
 * (C) 2005-2006 Harald Welte <[email protected]>
 *  - 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 <asm/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(unsigned long dummy)
{
    struct reader_dev *dev = (struct reader_dev *) dummy;
    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;
    unsigned char uc;

    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;
    }

    uc = 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 unsigned int cm4040_poll(struct file *filp, poll_table *wait)
{
    struct reader_dev *dev = filp->private_data;
    unsigned int mask = 0;

    poll_wait(filp, &dev->poll_wait, wait);

    if (test_and_clear_bit(BS_READABLE, &dev->buffer_status))
        mask |= POLLIN | POLLRDNORM;
    if (test_and_clear_bit(BS_WRITABLE, &dev->buffer_status))
        mask |= POLLOUT | POLLWRNORM;

    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;

    dev->poll_timer.data = (unsigned long) dev;
    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, KERN_INFO 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_printk(KERN_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);
    setup_timer(&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");