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>

drivers/staging/lirc/lirc_imon.c

+/*
+ *   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);