V4L/DVB: staging/lirc: add lirc_imon driver

Nb: this is a very trimmed-down lirc_imon, which only supports the
oldest generation of imon devices that don't do onboard signal decoding
like the most recent generation imon devices -- those are now supported
by the ir-core imon driver.

Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 1058 insertions, 0 deletions

diff --git a/drivers/staging/lirc/lirc_imon.c b/drivers/staging/lirc/lirc_imon.c
new file mode 100644
index 000000000000..43856d6818dd
--- /dev/null
+++ b/drivers/staging/lirc/lirc_imon.c
@@ -0,0 +1,1058 @@
+/*
+ *   lirc_imon.c:  LIRC/VFD/LCD driver for SoundGraph iMON IR/VFD/LCD
+ *                 including the iMON PAD model
+ *
+ *   Copyright(C) 2004  Venky Raju(dev@venky.ws)
+ *   Copyright(C) 2009  Jarod Wilson <jarod@wilsonet.com>
+ *
+ *   lirc_imon 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.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/usb.h>
+
+#include <media/lirc.h>
+#include <media/lirc_dev.h>
+
+
+#define MOD_AUTHOR      "Venky Raju <dev@venky.ws>"
+#define MOD_DESC        "Driver for SoundGraph iMON MultiMedia IR/Display"
+#define MOD_NAME        "lirc_imon"
+#define MOD_VERSION     "0.8"
+
+#define DISPLAY_MINOR_BASE      144
+#define DEVICE_NAME     "lcd%d"
+
+#define BUF_CHUNK_SIZE  4
+#define BUF_SIZE        128
+
+#define BIT_DURATION    250     /* each bit received is 250us */
+
+/*** P R O T O T Y P E S ***/
+
+/* USB Callback prototypes */
+static int imon_probe(struct usb_interface *interface,
+                      const struct usb_device_id *id);
+static void imon_disconnect(struct usb_interface *interface);
+static void usb_rx_callback(struct urb *urb);
+static void usb_tx_callback(struct urb *urb);
+
+/* suspend/resume support */
+static int imon_resume(struct usb_interface *intf);
+static int imon_suspend(struct usb_interface *intf, pm_message_t message);
+
+/* Display file_operations function prototypes */
+static int display_open(struct inode *inode, struct file *file);
+static int display_close(struct inode *inode, struct file *file);
+
+/* VFD write operation */
+static ssize_t vfd_write(struct file *file, const char *buf,
+                         size_t n_bytes, loff_t *pos);
+
+/* LIRC driver function prototypes */
+static int ir_open(void *data);
+static void ir_close(void *data);
+
+/* Driver init/exit prototypes */
+static int __init imon_init(void);
+static void __exit imon_exit(void);
+
+/*** G L O B A L S ***/
+#define IMON_DATA_BUF_SZ        35
+
+struct imon_context {
+        struct usb_device *usbdev;
+        /* Newer devices have two interfaces */
+        int display;                    /* not all controllers do */
+        int display_isopen;             /* display port has been opened */
+        int ir_isopen;                  /* IR port open */
+        int dev_present;                /* USB device presence */
+        struct mutex ctx_lock;          /* to lock this object */
+        wait_queue_head_t remove_ok;    /* For unexpected USB disconnects */
+
+        int vfd_proto_6p;               /* some VFD require a 6th packet */
+
+        struct lirc_driver *driver;
+        struct usb_endpoint_descriptor *rx_endpoint;
+        struct usb_endpoint_descriptor *tx_endpoint;
+        struct urb *rx_urb;
+        struct urb *tx_urb;
+        unsigned char usb_rx_buf[8];
+        unsigned char usb_tx_buf[8];
+
+        struct rx_data {
+                int count;              /* length of 0 or 1 sequence */
+                int prev_bit;           /* logic level of sequence */
+                int initial_space;      /* initial space flag */
+        } rx;
+
+        struct tx_t {
+                unsigned char data_buf[IMON_DATA_BUF_SZ]; /* user data buffer */
+                struct completion finished;     /* wait for write to finish */
+                atomic_t busy;                  /* write in progress */
+                int status;                     /* status of tx completion */
+        } tx;
+};
+
+static struct file_operations display_fops = {
+        .owner          = THIS_MODULE,
+        .open           = &display_open,
+        .write          = &vfd_write,
+        .release        = &display_close
+};
+
+/*
+ * USB Device ID for iMON USB Control Boards
+ *
+ * The Windows drivers contain 6 different inf files, more or less one for
+ * each new device until the 0x0034-0x0046 devices, which all use the same
+ * driver. Some of the devices in the 34-46 range haven't been definitively
+ * identified yet. Early devices have either a TriGem Computer, Inc. or a
+ * Samsung vendor ID (0x0aa8 and 0x04e8 respectively), while all later
+ * devices use the SoundGraph vendor ID (0x15c2).
+ */
+static struct usb_device_id imon_usb_id_table[] = {
+        /* TriGem iMON (IR only) -- TG_iMON.inf */
+        { USB_DEVICE(0x0aa8, 0x8001) },
+
+        /* SoundGraph iMON (IR only) -- sg_imon.inf */
+        { USB_DEVICE(0x04e8, 0xff30) },
+
+        /* SoundGraph iMON VFD (IR & VFD) -- iMON_VFD.inf */
+        { USB_DEVICE(0x0aa8, 0xffda) },
+
+        /* SoundGraph iMON SS (IR & VFD) -- iMON_SS.inf */
+        { USB_DEVICE(0x15c2, 0xffda) },
+
+        {}
+};
+
+/* Some iMON VFD models requires a 6th packet for VFD writes */
+static struct usb_device_id vfd_proto_6p_list[] = {
+        { USB_DEVICE(0x15c2, 0xffda) },
+        {}
+};
+
+/* Some iMON devices have no lcd/vfd, don't set one up */
+static struct usb_device_id ir_only_list[] = {
+        { USB_DEVICE(0x0aa8, 0x8001) },
+        { USB_DEVICE(0x04e8, 0xff30) },
+        {}
+};
+
+/* USB Device data */
+static struct usb_driver imon_driver = {
+        .name           = MOD_NAME,
+        .probe          = imon_probe,
+        .disconnect     = imon_disconnect,
+        .suspend        = imon_suspend,
+        .resume         = imon_resume,
+        .id_table       = imon_usb_id_table,
+};
+
+static struct usb_class_driver imon_class = {
+        .name           = DEVICE_NAME,
+        .fops           = &display_fops,
+        .minor_base     = DISPLAY_MINOR_BASE,
+};
+
+/* to prevent races between open() and disconnect(), probing, etc */
+static DEFINE_MUTEX(driver_lock);
+
+static int debug;
+
+/***  M O D U L E   C O D E ***/
+
+MODULE_AUTHOR(MOD_AUTHOR);
+MODULE_DESCRIPTION(MOD_DESC);
+MODULE_VERSION(MOD_VERSION);
+MODULE_LICENSE("GPL");
+MODULE_DEVICE_TABLE(usb, imon_usb_id_table);
+module_param(debug, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(debug, "Debug messages: 0=no, 1=yes(default: no)");
+
+static void free_imon_context(struct imon_context *context)
+{
+        struct device *dev = context->driver->dev;
+        usb_free_urb(context->tx_urb);
+        usb_free_urb(context->rx_urb);
+        lirc_buffer_free(context->driver->rbuf);
+        kfree(context->driver->rbuf);
+        kfree(context->driver);
+        kfree(context);
+
+        dev_dbg(dev, "%s: iMON context freed\n", __func__);
+}
+
+static void deregister_from_lirc(struct imon_context *context)
+{
+        int retval;
+        int minor = context->driver->minor;
+
+        retval = lirc_unregister_driver(minor);
+        if (retval)
+                err("%s: unable to deregister from lirc(%d)",
+                        __func__, retval);
+        else
+                printk(KERN_INFO MOD_NAME ": Deregistered iMON driver "
+                       "(minor:%d)\n", minor);
+
+}
+
+/**
+ * Called when the Display device (e.g. /dev/lcd0)
+ * is opened by the application.
+ */
+static int display_open(struct inode *inode, struct file *file)
+{
+        struct usb_interface *interface;
+        struct imon_context *context = NULL;
+        int subminor;
+        int retval = 0;
+
+        /* prevent races with disconnect */
+        mutex_lock(&driver_lock);
+
+        subminor = iminor(inode);
+        interface = usb_find_interface(&imon_driver, subminor);
+        if (!interface) {
+                err("%s: could not find interface for minor %d",
+                    __func__, subminor);
+                retval = -ENODEV;
+                goto exit;
+        }
+        context = usb_get_intfdata(interface);
+
+        if (!context) {
+                err("%s: no context found for minor %d",
+                                        __func__, subminor);
+                retval = -ENODEV;
+                goto exit;
+        }
+
+        mutex_lock(&context->ctx_lock);
+
+        if (!context->display) {
+                err("%s: display not supported by device", __func__);
+                retval = -ENODEV;
+        } else if (context->display_isopen) {
+                err("%s: display port is already open", __func__);
+                retval = -EBUSY;
+        } else {
+                context->display_isopen = 1;
+                file->private_data = context;
+                dev_info(context->driver->dev, "display port opened\n");
+        }
+
+        mutex_unlock(&context->ctx_lock);
+
+exit:
+        mutex_unlock(&driver_lock);
+        return retval;
+}
+
+/**
+ * Called when the display device (e.g. /dev/lcd0)
+ * is closed by the application.
+ */
+static int display_close(struct inode *inode, struct file *file)
+{
+        struct imon_context *context = NULL;
+        int retval = 0;
+
+        context = (struct imon_context *)file->private_data;
+
+        if (!context) {
+                err("%s: no context for device", __func__);
+                return -ENODEV;
+        }
+
+        mutex_lock(&context->ctx_lock);
+
+        if (!context->display) {
+                err("%s: display not supported by device", __func__);
+                retval = -ENODEV;
+        } else if (!context->display_isopen) {
+                err("%s: display is not open", __func__);
+                retval = -EIO;
+        } else {
+                context->display_isopen = 0;
+                dev_info(context->driver->dev, "display port closed\n");
+                if (!context->dev_present && !context->ir_isopen) {
+                        /*
+                         * Device disconnected before close and IR port is not
+                         * open. If IR port is open, context will be deleted by
+                         * ir_close.
+                         */
+                        mutex_unlock(&context->ctx_lock);
+                        free_imon_context(context);
+                        return retval;
+                }
+        }
+
+        mutex_unlock(&context->ctx_lock);
+        return retval;
+}
+
+/**
+ * Sends a packet to the device -- this function must be called
+ * with context->ctx_lock held.
+ */
+static int send_packet(struct imon_context *context)
+{
+        unsigned int pipe;
+        int interval = 0;
+        int retval = 0;
+        struct usb_ctrlrequest *control_req = NULL;
+
+        /* Check if we need to use control or interrupt urb */
+        pipe = usb_sndintpipe(context->usbdev,
+                              context->tx_endpoint->bEndpointAddress);
+        interval = context->tx_endpoint->bInterval;
+
+        usb_fill_int_urb(context->tx_urb, context->usbdev, pipe,
+                         context->usb_tx_buf,
+                         sizeof(context->usb_tx_buf),
+                         usb_tx_callback, context, interval);
+
+        context->tx_urb->actual_length = 0;
+
+        init_completion(&context->tx.finished);
+        atomic_set(&(context->tx.busy), 1);
+
+        retval = usb_submit_urb(context->tx_urb, GFP_KERNEL);
+        if (retval) {
+                atomic_set(&(context->tx.busy), 0);
+                err("%s: error submitting urb(%d)", __func__, retval);
+        } else {
+                /* Wait for transmission to complete (or abort) */
+                mutex_unlock(&context->ctx_lock);
+                retval = wait_for_completion_interruptible(
+                                &context->tx.finished);
+                if (retval)
+                        err("%s: task interrupted", __func__);
+                mutex_lock(&context->ctx_lock);
+
+                retval = context->tx.status;
+                if (retval)
+                        err("%s: packet tx failed (%d)", __func__, retval);
+        }
+
+        kfree(control_req);
+
+        return retval;
+}
+
+/**
+ * Writes data to the VFD.  The iMON VFD is 2x16 characters
+ * and requires data in 5 consecutive USB interrupt packets,
+ * each packet but the last carrying 7 bytes.
+ *
+ * I don't know if the VFD board supports features such as
+ * scrolling, clearing rows, blanking, etc. so at
+ * the caller must provide a full screen of data.  If fewer
+ * than 32 bytes are provided spaces will be appended to
+ * generate a full screen.
+ */
+static ssize_t vfd_write(struct file *file, const char *buf,
+                         size_t n_bytes, loff_t *pos)
+{
+        int i;
+        int offset;
+        int seq;
+        int retval = 0;
+        struct imon_context *context;
+        const unsigned char vfd_packet6[] = {
+                0x01, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF };
+        int *data_buf;
+
+        context = (struct imon_context *)file->private_data;
+        if (!context) {
+                err("%s: no context for device", __func__);
+                return -ENODEV;
+        }
+
+        mutex_lock(&context->ctx_lock);
+
+        if (!context->dev_present) {
+                err("%s: no iMON device present", __func__);
+                retval = -ENODEV;
+                goto exit;
+        }
+
+        if (n_bytes <= 0 || n_bytes > IMON_DATA_BUF_SZ - 3) {
+                err("%s: invalid payload size", __func__);
+                retval = -EINVAL;
+                goto exit;
+        }
+
+        data_buf = memdup_user(buf, n_bytes);
+        if (IS_ERR(data_buf)) {
+                retval = PTR_ERR(data_buf);
+                goto exit;
+        }
+
+        memcpy(context->tx.data_buf, data_buf, n_bytes);
+
+        /* Pad with spaces */
+        for (i = n_bytes; i < IMON_DATA_BUF_SZ - 3; ++i)
+                context->tx.data_buf[i] = ' ';
+
+        for (i = IMON_DATA_BUF_SZ - 3; i < IMON_DATA_BUF_SZ; ++i)
+                context->tx.data_buf[i] = 0xFF;
+
+        offset = 0;
+        seq = 0;
+
+        do {
+                memcpy(context->usb_tx_buf, context->tx.data_buf + offset, 7);
+                context->usb_tx_buf[7] = (unsigned char) seq;
+
+                retval = send_packet(context);
+                if (retval) {
+                        err("%s: send packet failed for packet #%d",
+                                        __func__, seq/2);
+                        goto exit;
+                } else {
+                        seq += 2;
+                        offset += 7;
+                }
+
+        } while (offset < IMON_DATA_BUF_SZ);
+
+        if (context->vfd_proto_6p) {
+                /* Send packet #6 */
+                memcpy(context->usb_tx_buf, &vfd_packet6, sizeof(vfd_packet6));
+                context->usb_tx_buf[7] = (unsigned char) seq;
+                retval = send_packet(context);
+                if (retval)
+                        err("%s: send packet failed for packet #%d",
+                                        __func__, seq/2);
+        }
+
+exit:
+        mutex_unlock(&context->ctx_lock);
+
+        return (!retval) ? n_bytes : retval;
+}
+
+/**
+ * Callback function for USB core API: transmit data
+ */
+static void usb_tx_callback(struct urb *urb)
+{
+        struct imon_context *context;
+
+        if (!urb)
+                return;
+        context = (struct imon_context *)urb->context;
+        if (!context)
+                return;
+
+        context->tx.status = urb->status;
+
+        /* notify waiters that write has finished */
+        atomic_set(&context->tx.busy, 0);
+        complete(&context->tx.finished);
+
+        return;
+}
+
+/**
+ * Called by lirc_dev when the application opens /dev/lirc
+ */
+static int ir_open(void *data)
+{
+        int retval = 0;
+        struct imon_context *context;
+
+        /* prevent races with disconnect */
+        mutex_lock(&driver_lock);
+
+        context = (struct imon_context *)data;
+
+        /* initial IR protocol decode variables */
+        context->rx.count = 0;
+        context->rx.initial_space = 1;
+        context->rx.prev_bit = 0;
+
+        context->ir_isopen = 1;
+        dev_info(context->driver->dev, "IR port opened\n");
+
+        mutex_unlock(&driver_lock);
+        return retval;
+}
+
+/**
+ * Called by lirc_dev when the application closes /dev/lirc
+ */
+static void ir_close(void *data)
+{
+        struct imon_context *context;
+
+        context = (struct imon_context *)data;
+        if (!context) {
+                err("%s: no context for device", __func__);
+                return;
+        }
+
+        mutex_lock(&context->ctx_lock);
+
+        context->ir_isopen = 0;
+        dev_info(context->driver->dev, "IR port closed\n");
+
+        if (!context->dev_present) {
+                /*
+                 * Device disconnected while IR port was still open. Driver
+                 * was not deregistered at disconnect time, so do it now.
+                 */
+                deregister_from_lirc(context);
+
+                if (!context->display_isopen) {
+                        mutex_unlock(&context->ctx_lock);
+                        free_imon_context(context);
+                        return;
+                }
+                /*
+                 * If display port is open, context will be deleted by
+                 * display_close
+                 */
+        }
+
+        mutex_unlock(&context->ctx_lock);
+        return;
+}
+
+/**
+ * Convert bit count to time duration (in us) and submit
+ * the value to lirc_dev.
+ */
+static void submit_data(struct imon_context *context)
+{
+        unsigned char buf[4];
+        int value = context->rx.count;
+        int i;
+
+        dev_dbg(context->driver->dev, "submitting data to LIRC\n");
+
+        value *= BIT_DURATION;
+        value &= PULSE_MASK;
+        if (context->rx.prev_bit)
+                value |= PULSE_BIT;
+
+        for (i = 0; i < 4; ++i)
+                buf[i] = value>>(i*8);
+
+        lirc_buffer_write(context->driver->rbuf, buf);
+        wake_up(&context->driver->rbuf->wait_poll);
+        return;
+}
+
+static inline int tv2int(const struct timeval *a, const struct timeval *b)
+{
+        int usecs = 0;
+        int sec   = 0;
+
+        if (b->tv_usec > a->tv_usec) {
+                usecs = 1000000;
+                sec--;
+        }
+
+        usecs += a->tv_usec - b->tv_usec;
+
+        sec += a->tv_sec - b->tv_sec;
+        sec *= 1000;
+        usecs /= 1000;
+        sec += usecs;
+
+        if (sec < 0)
+                sec = 1000;
+
+        return sec;
+}
+
+/**
+ * Process the incoming packet
+ */
+static void imon_incoming_packet(struct imon_context *context,
+                                 struct urb *urb, int intf)
+{
+        int len = urb->actual_length;
+        unsigned char *buf = urb->transfer_buffer;
+        struct device *dev = context->driver->dev;
+        int octet, bit;
+        unsigned char mask;
+        int i, chunk_num;
+
+        /*
+         * just bail out if no listening IR client
+         */
+        if (!context->ir_isopen)
+                return;
+
+        if (len != 8) {
+                dev_warn(dev, "imon %s: invalid incoming packet "
+                         "size (len = %d, intf%d)\n", __func__, len, intf);
+                return;
+        }
+
+        if (debug) {
+                printk(KERN_INFO "raw packet: ");
+                for (i = 0; i < len; ++i)
+                        printk("%02x ", buf[i]);
+                printk("\n");
+        }
+
+        /*
+         * Translate received data to pulse and space lengths.
+         * Received data is active low, i.e. pulses are 0 and
+         * spaces are 1.
+         *
+         * My original algorithm was essentially similar to
+         * Changwoo Ryu's with the exception that he switched
+         * the incoming bits to active high and also fed an
+         * initial space to LIRC at the start of a new sequence
+         * if the previous bit was a pulse.
+         *
+         * I've decided to adopt his algorithm.
+         */
+
+        if (buf[7] == 1 && context->rx.initial_space) {
+                /* LIRC requires a leading space */
+                context->rx.prev_bit = 0;
+                context->rx.count = 4;
+                submit_data(context);
+                context->rx.count = 0;
+        }
+
+        for (octet = 0; octet < 5; ++octet) {
+                mask = 0x80;
+                for (bit = 0; bit < 8; ++bit) {
+                        int curr_bit = !(buf[octet] & mask);
+                        if (curr_bit != context->rx.prev_bit) {
+                                if (context->rx.count) {
+                                        submit_data(context);
+                                        context->rx.count = 0;
+                                }
+                                context->rx.prev_bit = curr_bit;
+                        }
+                        ++context->rx.count;
+                        mask >>= 1;
+                }
+        }
+
+        if (chunk_num == 10) {
+                if (context->rx.count) {
+                        submit_data(context);
+                        context->rx.count = 0;
+                }
+                context->rx.initial_space = context->rx.prev_bit;
+        }
+}
+
+/**
+ * Callback function for USB core API: receive data
+ */
+static void usb_rx_callback(struct urb *urb)
+{
+        struct imon_context *context;
+        unsigned char *buf;
+        int len;
+        int intfnum = 0;
+
+        if (!urb)
+                return;
+
+        context = (struct imon_context *)urb->context;
+        if (!context)
+                return;
+
+        buf = urb->transfer_buffer;
+        len = urb->actual_length;
+
+        switch (urb->status) {
+        case -ENOENT:           /* usbcore unlink successful! */
+                return;
+
+        case 0:
+                imon_incoming_packet(context, urb, intfnum);
+                break;
+
+        default:
+                dev_warn(context->driver->dev, "imon %s: status(%d): ignored\n",
+                         __func__, urb->status);
+                break;
+        }
+
+        usb_submit_urb(context->rx_urb, GFP_ATOMIC);
+
+        return;
+}
+
+/**
+ * Callback function for USB core API: Probe
+ */
+static int imon_probe(struct usb_interface *interface,
+                      const struct usb_device_id *id)
+{
+        struct usb_device *usbdev = NULL;
+        struct usb_host_interface *iface_desc = NULL;
+        struct usb_endpoint_descriptor *rx_endpoint = NULL;
+        struct usb_endpoint_descriptor *tx_endpoint = NULL;
+        struct urb *rx_urb = NULL;
+        struct urb *tx_urb = NULL;
+        struct lirc_driver *driver = NULL;
+        struct lirc_buffer *rbuf = NULL;
+        struct device *dev = &interface->dev;
+        int ifnum;
+        int lirc_minor = 0;
+        int num_endpts;
+        int retval = 0;
+        int display_ep_found = 0;
+        int ir_ep_found = 0;
+        int alloc_status = 0;
+        int vfd_proto_6p = 0;
+        int code_length;
+        struct imon_context *context = NULL;
+        int i;
+        u16 vendor, product;
+
+        context = kzalloc(sizeof(struct imon_context), GFP_KERNEL);
+        if (!context) {
+                err("%s: kzalloc failed for context", __func__);
+                alloc_status = 1;
+                goto alloc_status_switch;
+        }
+
+        /*
+         * Try to auto-detect the type of display if the user hasn't set
+         * it by hand via the display_type modparam. Default is VFD.
+         */
+        if (usb_match_id(interface, ir_only_list))
+                context->display = 0;
+        else
+                context->display = 1;
+
+        code_length = BUF_CHUNK_SIZE * 8;
+
+        usbdev     = usb_get_dev(interface_to_usbdev(interface));
+        iface_desc = interface->cur_altsetting;
+        num_endpts = iface_desc->desc.bNumEndpoints;
+        ifnum      = iface_desc->desc.bInterfaceNumber;
+        vendor     = le16_to_cpu(usbdev->descriptor.idVendor);
+        product    = le16_to_cpu(usbdev->descriptor.idProduct);
+
+        dev_dbg(dev, "%s: found iMON device (%04x:%04x, intf%d)\n",
+                __func__, vendor, product, ifnum);
+
+        /* prevent races probing devices w/multiple interfaces */
+        mutex_lock(&driver_lock);
+
+        /*
+         * Scan the endpoint list and set:
+         *      first input endpoint = IR endpoint
+         *      first output endpoint = display endpoint
+         */
+        for (i = 0; i < num_endpts && !(ir_ep_found && display_ep_found); ++i) {
+                struct usb_endpoint_descriptor *ep;
+                int ep_dir;
+                int ep_type;
+                ep = &iface_desc->endpoint[i].desc;
+                ep_dir = ep->bEndpointAddress & USB_ENDPOINT_DIR_MASK;
+                ep_type = ep->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
+
+                if (!ir_ep_found &&
+                        ep_dir == USB_DIR_IN &&
+                        ep_type == USB_ENDPOINT_XFER_INT) {
+
+                        rx_endpoint = ep;
+                        ir_ep_found = 1;
+                        dev_dbg(dev, "%s: found IR endpoint\n", __func__);
+
+                } else if (!display_ep_found && ep_dir == USB_DIR_OUT &&
+                           ep_type == USB_ENDPOINT_XFER_INT) {
+                        tx_endpoint = ep;
+                        display_ep_found = 1;
+                        dev_dbg(dev, "%s: found display endpoint\n", __func__);
+                }
+        }
+
+        /*
+         * Some iMON receivers have no display. Unfortunately, it seems
+         * that SoundGraph recycles device IDs between devices both with
+         * and without... :\
+         */
+        if (context->display == 0) {
+                display_ep_found = 0;
+                dev_dbg(dev, "%s: device has no display\n", __func__);
+        }
+
+        /* Input endpoint is mandatory */
+        if (!ir_ep_found) {
+                err("%s: no valid input (IR) endpoint found.", __func__);
+                retval = -ENODEV;
+                alloc_status = 2;
+                goto alloc_status_switch;
+        }
+
+        /* Determine if display requires 6 packets */
+        if (display_ep_found) {
+                if (usb_match_id(interface, vfd_proto_6p_list))
+                        vfd_proto_6p = 1;
+
+                dev_dbg(dev, "%s: vfd_proto_6p: %d\n",
+                        __func__, vfd_proto_6p);
+        }
+
+        driver = kzalloc(sizeof(struct lirc_driver), GFP_KERNEL);
+        if (!driver) {
+                err("%s: kzalloc failed for lirc_driver", __func__);
+                alloc_status = 2;
+                goto alloc_status_switch;
+        }
+        rbuf = kmalloc(sizeof(struct lirc_buffer), GFP_KERNEL);
+        if (!rbuf) {
+                err("%s: kmalloc failed for lirc_buffer", __func__);
+                alloc_status = 3;
+                goto alloc_status_switch;
+        }
+        if (lirc_buffer_init(rbuf, BUF_CHUNK_SIZE, BUF_SIZE)) {
+                err("%s: lirc_buffer_init failed", __func__);
+                alloc_status = 4;
+                goto alloc_status_switch;
+        }
+        rx_urb = usb_alloc_urb(0, GFP_KERNEL);
+        if (!rx_urb) {
+                err("%s: usb_alloc_urb failed for IR urb", __func__);
+                alloc_status = 5;
+                goto alloc_status_switch;
+        }
+        tx_urb = usb_alloc_urb(0, GFP_KERNEL);
+        if (!tx_urb) {
+                err("%s: usb_alloc_urb failed for display urb",
+                    __func__);
+                alloc_status = 6;
+                goto alloc_status_switch;
+        }
+
+        mutex_init(&context->ctx_lock);
+        context->vfd_proto_6p = vfd_proto_6p;
+
+        strcpy(driver->name, MOD_NAME);
+        driver->minor = -1;
+        driver->code_length = sizeof(int) * 8;
+        driver->sample_rate = 0;
+        driver->features = LIRC_CAN_REC_MODE2;
+        driver->data = context;
+        driver->rbuf = rbuf;
+        driver->set_use_inc = ir_open;
+        driver->set_use_dec = ir_close;
+        driver->dev = &interface->dev;
+        driver->owner = THIS_MODULE;
+
+        mutex_lock(&context->ctx_lock);
+
+        context->driver = driver;
+        /* start out in keyboard mode */
+
+        lirc_minor = lirc_register_driver(driver);
+        if (lirc_minor < 0) {
+                err("%s: lirc_register_driver failed", __func__);
+                alloc_status = 7;
+                goto alloc_status_switch;
+        } else
+                dev_info(dev, "Registered iMON driver "
+                         "(lirc minor: %d)\n", lirc_minor);
+
+        /* Needed while unregistering! */
+        driver->minor = lirc_minor;
+
+        context->usbdev = usbdev;
+        context->dev_present = 1;
+        context->rx_endpoint = rx_endpoint;
+        context->rx_urb = rx_urb;
+
+        /*
+         * tx is used to send characters to lcd/vfd, associate RF
+         * remotes, set IR protocol, and maybe more...
+         */
+        context->tx_endpoint = tx_endpoint;
+        context->tx_urb = tx_urb;
+
+        if (display_ep_found)
+                context->display = 1;
+
+        usb_fill_int_urb(context->rx_urb, context->usbdev,
+                usb_rcvintpipe(context->usbdev,
+                        context->rx_endpoint->bEndpointAddress),
+                context->usb_rx_buf, sizeof(context->usb_rx_buf),
+                usb_rx_callback, context,
+                context->rx_endpoint->bInterval);
+
+        retval = usb_submit_urb(context->rx_urb, GFP_KERNEL);
+
+        if (retval) {
+                err("%s: usb_submit_urb failed for intf0 (%d)",
+                    __func__, retval);
+                mutex_unlock(&context->ctx_lock);
+                goto exit;
+        }
+
+        usb_set_intfdata(interface, context);
+
+        if (context->display && ifnum == 0) {
+                dev_dbg(dev, "%s: Registering iMON display with sysfs\n",
+                        __func__);
+
+                if (usb_register_dev(interface, &imon_class)) {
+                        /* Not a fatal error, so ignore */
+                        dev_info(dev, "%s: could not get a minor number for "
+                                 "display\n", __func__);
+                }
+        }
+
+        dev_info(dev, "iMON device (%04x:%04x, intf%d) on "
+                 "usb<%d:%d> initialized\n", vendor, product, ifnum,
+                 usbdev->bus->busnum, usbdev->devnum);
+
+alloc_status_switch:
+        mutex_unlock(&context->ctx_lock);
+
+        switch (alloc_status) {
+        case 7:
+                usb_free_urb(tx_urb);
+        case 6:
+                usb_free_urb(rx_urb);
+        case 5:
+                if (rbuf)
+                        lirc_buffer_free(rbuf);
+        case 4:
+                kfree(rbuf);
+        case 3:
+                kfree(driver);
+        case 2:
+                kfree(context);
+                context = NULL;
+        case 1:
+                if (retval != -ENODEV)
+                        retval = -ENOMEM;
+                break;
+        case 0:
+                retval = 0;
+        }
+
+exit:
+        mutex_unlock(&driver_lock);
+
+        return retval;
+}
+
+/**
+ * Callback function for USB core API: disconnect
+ */
+static void imon_disconnect(struct usb_interface *interface)
+{
+        struct imon_context *context;
+        int ifnum;
+
+        /* prevent races with ir_open()/display_open() */
+        mutex_lock(&driver_lock);
+
+        context = usb_get_intfdata(interface);
+        ifnum = interface->cur_altsetting->desc.bInterfaceNumber;
+
+        mutex_lock(&context->ctx_lock);
+
+        usb_set_intfdata(interface, NULL);
+
+        /* Abort ongoing write */
+        if (atomic_read(&context->tx.busy)) {
+                usb_kill_urb(context->tx_urb);
+                complete_all(&context->tx.finished);
+        }
+
+        context->dev_present = 0;
+        usb_kill_urb(context->rx_urb);
+        if (context->display)
+                usb_deregister_dev(interface, &imon_class);
+
+        if (!context->ir_isopen && !context->dev_present) {
+                deregister_from_lirc(context);
+                mutex_unlock(&context->ctx_lock);
+                if (!context->display_isopen)
+                        free_imon_context(context);
+        } else
+                mutex_unlock(&context->ctx_lock);
+
+        mutex_unlock(&driver_lock);
+
+        printk(KERN_INFO "%s: iMON device (intf%d) disconnected\n",
+               __func__, ifnum);
+}
+
+static int imon_suspend(struct usb_interface *intf, pm_message_t message)
+{
+        struct imon_context *context = usb_get_intfdata(intf);
+
+        usb_kill_urb(context->rx_urb);
+
+        return 0;
+}
+
+static int imon_resume(struct usb_interface *intf)
+{
+        int rc = 0;
+        struct imon_context *context = usb_get_intfdata(intf);
+
+        usb_fill_int_urb(context->rx_urb, context->usbdev,
+                usb_rcvintpipe(context->usbdev,
+                        context->rx_endpoint->bEndpointAddress),
+                context->usb_rx_buf, sizeof(context->usb_rx_buf),
+                usb_rx_callback, context,
+                context->rx_endpoint->bInterval);
+
+        rc = usb_submit_urb(context->rx_urb, GFP_ATOMIC);
+
+        return rc;
+}
+
+static int __init imon_init(void)
+{
+        int rc;
+
+        printk(KERN_INFO MOD_NAME ": " MOD_DESC ", v" MOD_VERSION "\n");
+
+        rc = usb_register(&imon_driver);
+        if (rc) {
+                err("%s: usb register failed(%d)", __func__, rc);
+                return -ENODEV;
+        }
+
+        return 0;
+}
+
+static void __exit imon_exit(void)
+{
+        usb_deregister(&imon_driver);
+        printk(KERN_INFO MOD_NAME ": module removed. Goodbye!\n");
+}
+
+module_init(imon_init);
+module_exit(imon_exit);