cyberjack.c

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/*
 *  REINER SCT cyberJack pinpad/e-com USB Chipcard Reader Driver
 *
 *  Copyright (C) 2001  REINER SCT
 *  Author: Matthias Bruestle
 *
 *  Contact: [email protected] (see MAINTAINERS)
 *
 *  This program is largely derived from work by the linux-usb group
 *  and associated source files.  Please see the usb/serial files for
 *  individual credits and copyrights.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  Thanks to Greg Kroah-Hartman ([email protected]) for his help and
 *  patience.
 *
 *  In case of problems, please write to the contact e-mail address
 *  mentioned above.
 *
 *  Please note that later models of the cyberjack reader family are
 *  supported by a libusb-based userspace device driver.
 *
 *  Homepage: http://www.reiner-sct.de/support/treiber_cyberjack.php#linux
 */


#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>

#define CYBERJACK_LOCAL_BUF_SIZE 32

/*
 * Version Information
 */
#define DRIVER_VERSION "v1.01"
#define DRIVER_AUTHOR "Matthias Bruestle"
#define DRIVER_DESC "REINER SCT cyberJack pinpad/e-com USB Chipcard Reader Driver"


#define CYBERJACK_VENDOR_ID 0x0C4B
#define CYBERJACK_PRODUCT_ID    0x0100

/* Function prototypes */
static void cyberjack_disconnect(struct usb_serial *serial);
static int cyberjack_port_probe(struct usb_serial_port *port);
static int cyberjack_port_remove(struct usb_serial_port *port);
static int  cyberjack_open(struct tty_struct *tty,
    struct usb_serial_port *port);
static void cyberjack_close(struct usb_serial_port *port);
static int cyberjack_write(struct tty_struct *tty,
    struct usb_serial_port *port, const unsigned char *buf, int count);
static int cyberjack_write_room(struct tty_struct *tty);
static void cyberjack_read_int_callback(struct urb *urb);
static void cyberjack_read_bulk_callback(struct urb *urb);
static void cyberjack_write_bulk_callback(struct urb *urb);

static const struct usb_device_id id_table[] = {
    { USB_DEVICE(CYBERJACK_VENDOR_ID, CYBERJACK_PRODUCT_ID) },
    { }         /* Terminating entry */
};

MODULE_DEVICE_TABLE(usb, id_table);

static struct usb_serial_driver cyberjack_device = {
    .driver = {
        .owner =    THIS_MODULE,
        .name =     "cyberjack",
    },
    .description =      "Reiner SCT Cyberjack USB card reader",
    .id_table =     id_table,
    .num_ports =        1,
    .disconnect =       cyberjack_disconnect,
    .port_probe =       cyberjack_port_probe,
    .port_remove =      cyberjack_port_remove,
    .open =         cyberjack_open,
    .close =        cyberjack_close,
    .write =        cyberjack_write,
    .write_room =       cyberjack_write_room,
    .read_int_callback =    cyberjack_read_int_callback,
    .read_bulk_callback =   cyberjack_read_bulk_callback,
    .write_bulk_callback =  cyberjack_write_bulk_callback,
};

static struct usb_serial_driver * const serial_drivers[] = {
    &cyberjack_device, NULL
};

struct cyberjack_private {
    spinlock_t  lock;       /* Lock for SMP */
    short       rdtodo;     /* Bytes still to read */
    unsigned char   wrbuf[5*64];    /* Buffer for collecting data to write */
    short       wrfilled;   /* Overall data size we already got */
    short       wrsent;     /* Data already sent */
};

static int cyberjack_port_probe(struct usb_serial_port *port)
{
    struct cyberjack_private *priv;
    int result;

    priv = kmalloc(sizeof(struct cyberjack_private), GFP_KERNEL);
    if (!priv)
        return -ENOMEM;

    spin_lock_init(&priv->lock);
    priv->rdtodo = 0;
    priv->wrfilled = 0;
    priv->wrsent = 0;

    usb_set_serial_port_data(port, priv);

    result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
    if (result)
        dev_err(&port->dev, "usb_submit_urb(read int) failed\n");

    return 0;
}

static int cyberjack_port_remove(struct usb_serial_port *port)
{
    struct cyberjack_private *priv;

    priv = usb_get_serial_port_data(port);
    kfree(priv);

    return 0;
}

static void cyberjack_disconnect(struct usb_serial *serial)
{
    int i;

    for (i = 0; i < serial->num_ports; ++i)
        usb_kill_urb(serial->port[i]->interrupt_in_urb);
}

static int  cyberjack_open(struct tty_struct *tty,
                    struct usb_serial_port *port)
{
    struct cyberjack_private *priv;
    unsigned long flags;
    int result = 0;

    dev_dbg(&port->dev, "%s - usb_clear_halt\n", __func__);
    usb_clear_halt(port->serial->dev, port->write_urb->pipe);

    priv = usb_get_serial_port_data(port);
    spin_lock_irqsave(&priv->lock, flags);
    priv->rdtodo = 0;
    priv->wrfilled = 0;
    priv->wrsent = 0;
    spin_unlock_irqrestore(&priv->lock, flags);

    return result;
}

static void cyberjack_close(struct usb_serial_port *port)
{
    if (port->serial->dev) {
        /* shutdown any bulk reads that might be going on */
        usb_kill_urb(port->write_urb);
        usb_kill_urb(port->read_urb);
    }
}

static int cyberjack_write(struct tty_struct *tty,
    struct usb_serial_port *port, const unsigned char *buf, int count)
{
    struct device *dev = &port->dev;
    struct cyberjack_private *priv = usb_get_serial_port_data(port);
    unsigned long flags;
    int result;
    int wrexpected;

    if (count == 0) {
        dev_dbg(dev, "%s - write request of 0 bytes\n", __func__);
        return 0;
    }

    if (!test_and_clear_bit(0, &port->write_urbs_free)) {
        dev_dbg(dev, "%s - already writing\n", __func__);
        return 0;
    }

    spin_lock_irqsave(&priv->lock, flags);

    if (count+priv->wrfilled > sizeof(priv->wrbuf)) {
        /* To much data for buffer. Reset buffer. */
        priv->wrfilled = 0;
        spin_unlock_irqrestore(&priv->lock, flags);
        set_bit(0, &port->write_urbs_free);
        return 0;
    }

    /* Copy data */
    memcpy(priv->wrbuf + priv->wrfilled, buf, count);

    usb_serial_debug_data(dev, __func__, count, priv->wrbuf + priv->wrfilled);
    priv->wrfilled += count;

    if (priv->wrfilled >= 3) {
        wrexpected = ((int)priv->wrbuf[2]<<8)+priv->wrbuf[1]+3;
        dev_dbg(dev, "%s - expected data: %d\n", __func__, wrexpected);
    } else
        wrexpected = sizeof(priv->wrbuf);

    if (priv->wrfilled >= wrexpected) {
        /* We have enough data to begin transmission */
        int length;

        dev_dbg(dev, "%s - transmitting data (frame 1)\n", __func__);
        length = (wrexpected > port->bulk_out_size) ?
                    port->bulk_out_size : wrexpected;

        memcpy(port->write_urb->transfer_buffer, priv->wrbuf, length);
        priv->wrsent = length;

        /* set up our urb */
        port->write_urb->transfer_buffer_length = length;

        /* send the data out the bulk port */
        result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
        if (result) {
            dev_err(&port->dev,
                "%s - failed submitting write urb, error %d",
                __func__, result);
            /* Throw away data. No better idea what to do with it. */
            priv->wrfilled = 0;
            priv->wrsent = 0;
            spin_unlock_irqrestore(&priv->lock, flags);
            set_bit(0, &port->write_urbs_free);
            return 0;
        }

        dev_dbg(dev, "%s - priv->wrsent=%d\n", __func__, priv->wrsent);
        dev_dbg(dev, "%s - priv->wrfilled=%d\n", __func__, priv->wrfilled);

        if (priv->wrsent >= priv->wrfilled) {
            dev_dbg(dev, "%s - buffer cleaned\n", __func__);
            memset(priv->wrbuf, 0, sizeof(priv->wrbuf));
            priv->wrfilled = 0;
            priv->wrsent = 0;
        }
    }

    spin_unlock_irqrestore(&priv->lock, flags);

    return count;
}

static int cyberjack_write_room(struct tty_struct *tty)
{
    /* FIXME: .... */
    return CYBERJACK_LOCAL_BUF_SIZE;
}

static void cyberjack_read_int_callback(struct urb *urb)
{
    struct usb_serial_port *port = urb->context;
    struct cyberjack_private *priv = usb_get_serial_port_data(port);
    struct device *dev = &port->dev;
    unsigned char *data = urb->transfer_buffer;
    int status = urb->status;
    int result;

    /* the urb might have been killed. */
    if (status)
        return;

    usb_serial_debug_data(dev, __func__, urb->actual_length, data);

    /* React only to interrupts signaling a bulk_in transfer */
    if (urb->actual_length == 4 && data[0] == 0x01) {
        short old_rdtodo;

        /* This is a announcement of coming bulk_ins. */
        unsigned short size = ((unsigned short)data[3]<<8)+data[2]+3;

        spin_lock(&priv->lock);

        old_rdtodo = priv->rdtodo;

        if (old_rdtodo + size < old_rdtodo) {
            dev_dbg(dev, "To many bulk_in urbs to do.\n");
            spin_unlock(&priv->lock);
            goto resubmit;
        }

        /* "+=" is probably more fault tollerant than "=" */
        priv->rdtodo += size;

        dev_dbg(dev, "%s - rdtodo: %d\n", __func__, priv->rdtodo);

        spin_unlock(&priv->lock);

        if (!old_rdtodo) {
            result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
            if (result)
                dev_err(dev, "%s - failed resubmitting read urb, error %d\n",
                    __func__, result);
            dev_dbg(dev, "%s - usb_submit_urb(read urb)\n", __func__);
        }
    }

resubmit:
    result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
    if (result)
        dev_err(&port->dev, "usb_submit_urb(read int) failed\n");
    dev_dbg(dev, "%s - usb_submit_urb(int urb)\n", __func__);
}

static void cyberjack_read_bulk_callback(struct urb *urb)
{
    struct usb_serial_port *port = urb->context;
    struct cyberjack_private *priv = usb_get_serial_port_data(port);
    struct device *dev = &port->dev;
    struct tty_struct *tty;
    unsigned char *data = urb->transfer_buffer;
    short todo;
    int result;
    int status = urb->status;

    usb_serial_debug_data(dev, __func__, urb->actual_length, data);
    if (status) {
        dev_dbg(dev, "%s - nonzero read bulk status received: %d\n",
            __func__, status);
        return;
    }

    tty = tty_port_tty_get(&port->port);
    if (!tty) {
        dev_dbg(dev, "%s - ignoring since device not open\n", __func__);
        return;
    }
    if (urb->actual_length) {
        tty_insert_flip_string(tty, data, urb->actual_length);
        tty_flip_buffer_push(tty);
    }
    tty_kref_put(tty);

    spin_lock(&priv->lock);

    /* Reduce urbs to do by one. */
    priv->rdtodo -= urb->actual_length;
    /* Just to be sure */
    if (priv->rdtodo < 0)
        priv->rdtodo = 0;
    todo = priv->rdtodo;

    spin_unlock(&priv->lock);

    dev_dbg(dev, "%s - rdtodo: %d\n", __func__, todo);

    /* Continue to read if we have still urbs to do. */
    if (todo /* || (urb->actual_length==port->bulk_in_endpointAddress)*/) {
        result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
        if (result)
            dev_err(dev, "%s - failed resubmitting read urb, error %d\n",
                __func__, result);
        dev_dbg(dev, "%s - usb_submit_urb(read urb)\n", __func__);
    }
}

static void cyberjack_write_bulk_callback(struct urb *urb)
{
    struct usb_serial_port *port = urb->context;
    struct cyberjack_private *priv = usb_get_serial_port_data(port);
    struct device *dev = &port->dev;
    int status = urb->status;

    set_bit(0, &port->write_urbs_free);
    if (status) {
        dev_dbg(dev, "%s - nonzero write bulk status received: %d\n",
            __func__, status);
        return;
    }

    spin_lock(&priv->lock);

    /* only do something if we have more data to send */
    if (priv->wrfilled) {
        int length, blksize, result;

        dev_dbg(dev, "%s - transmitting data (frame n)\n", __func__);

        length = ((priv->wrfilled - priv->wrsent) > port->bulk_out_size) ?
            port->bulk_out_size : (priv->wrfilled - priv->wrsent);

        memcpy(port->write_urb->transfer_buffer,
                    priv->wrbuf + priv->wrsent, length);
        priv->wrsent += length;

        /* set up our urb */
        port->write_urb->transfer_buffer_length = length;

        /* send the data out the bulk port */
        result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
        if (result) {
            dev_err(dev, "%s - failed submitting write urb, error %d\n",
                __func__, result);
            /* Throw away data. No better idea what to do with it. */
            priv->wrfilled = 0;
            priv->wrsent = 0;
            goto exit;
        }

        dev_dbg(dev, "%s - priv->wrsent=%d\n", __func__, priv->wrsent);
        dev_dbg(dev, "%s - priv->wrfilled=%d\n", __func__, priv->wrfilled);

        blksize = ((int)priv->wrbuf[2]<<8)+priv->wrbuf[1]+3;

        if (priv->wrsent >= priv->wrfilled ||
                    priv->wrsent >= blksize) {
            dev_dbg(dev, "%s - buffer cleaned\n", __func__);
            memset(priv->wrbuf, 0, sizeof(priv->wrbuf));
            priv->wrfilled = 0;
            priv->wrsent = 0;
        }
    }

exit:
    spin_unlock(&priv->lock);
    usb_serial_port_softint(port);
}

module_usb_serial_driver(serial_drivers, id_table);

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_VERSION(DRIVER_VERSION);
MODULE_LICENSE("GPL");