V4L/DVB: staging/lirc: add lirc_sasem driver

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

drivers/staging/lirc/lirc_sasem.c

+/*
+ * lirc_sasem.c - USB remote support for LIRC
+ * Version 0.5
+ *
+ * Copyright (C) 2004-2005 Oliver Stabel <oliver.stabel@gmx.de>
+ *			 Tim Davies <tim@opensystems.net.au>
+ *
+ * This driver was derived from:
+ *   Venky Raju <dev@venky.ws>
+ *      "lirc_imon - "LIRC/VFD driver for Ahanix/Soundgraph IMON IR/VFD"
+ *   Paul Miller <pmiller9@users.sourceforge.net>'s 2003-2004
+ *      "lirc_atiusb - USB remote support for LIRC"
+ *   Culver Consulting Services <henry@culcon.com>'s 2003
+ *      "Sasem OnAir VFD/IR USB driver"
+ *
+ *
+ * NOTE - The LCDproc iMon driver should work with this module.  More info at
+ *	http://www.frogstorm.info/sasem
+ */
+
+/*
+ *  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.
+ *
+ *  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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  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	"Oliver Stabel <oliver.stabel@gmx.de>, " \
+			"Tim Davies <tim@opensystems.net.au>"
+#define MOD_DESC	"USB Driver for Sasem Remote Controller V1.1"
+#define MOD_NAME	"lirc_sasem"
+#define MOD_VERSION	"0.5"
+
+#define VFD_MINOR_BASE	144	/* Same as LCD */
+#define DEVICE_NAME	"lcd%d"
+
+#define BUF_CHUNK_SIZE	8
+#define BUF_SIZE	128
+
+#define IOCTL_LCD_CONTRAST 1
+
+/*** P R O T O T Y P E S ***/
+
+/* USB Callback prototypes */
+static int sasem_probe(struct usb_interface *interface,
+			const struct usb_device_id *id);
+static void sasem_disconnect(struct usb_interface *interface);
+static void usb_rx_callback(struct urb *urb);
+static void usb_tx_callback(struct urb *urb);
+
+/* VFD file_operations function prototypes */
+static int vfd_open(struct inode *inode, struct file *file);
+static long vfd_ioctl(struct file *file, unsigned cmd, unsigned long arg);
+static int vfd_close(struct inode *inode, struct file *file);
+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 sasem_init(void);
+static void __exit sasem_exit(void);
+
+/*** G L O B A L S ***/
+#define SASEM_DATA_BUF_SZ	32
+
+struct sasem_context {
+
+	struct usb_device *dev;
+	int vfd_isopen;			/* VFD port has been opened       */
+	unsigned int vfd_contrast;	/* VFD contrast		   */
+	int ir_isopen;			/* IR port has been opened	*/
+	int dev_present;		/* USB device presence	    */
+	struct mutex ctx_lock;		/* to lock this object	    */
+	wait_queue_head_t remove_ok;	/* For unexpected USB disconnects */
+
+	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 tx_t {
+		unsigned char data_buf[SASEM_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;
+
+	/* for dealing with repeat codes (wish there was a toggle bit!) */
+	struct timeval presstime;
+	char lastcode[8];
+	int codesaved;
+};
+
+/* VFD file operations */
+static struct file_operations vfd_fops = {
+	.owner		= THIS_MODULE,
+	.open		= &vfd_open,
+	.write		= &vfd_write,
+	.unlocked_ioctl	= &vfd_ioctl,
+	.release	= &vfd_close,
+};
+
+/* USB Device ID for Sasem USB Control Board */
+static struct usb_device_id sasem_usb_id_table[] = {
+	/* Sasem USB Control Board */
+	{ USB_DEVICE(0x11ba, 0x0101) },
+	/* Terminating entry */
+	{}
+};
+
+/* USB Device data */
+static struct usb_driver sasem_driver = {
+	.name		= MOD_NAME,
+	.probe		= sasem_probe,
+	.disconnect	= sasem_disconnect,
+	.id_table	= sasem_usb_id_table,
+};
+
+static struct usb_class_driver sasem_class = {
+	.name		= DEVICE_NAME,
+	.fops		= &vfd_fops,
+	.minor_base	= VFD_MINOR_BASE,
+};
+
+/* to prevent races between open() and disconnect() */
+static DEFINE_MUTEX(disconnect_lock);
+
+static int debug;
+
+
+/*** M O D U L E   C O D E ***/
+
+MODULE_AUTHOR(MOD_AUTHOR);
+MODULE_DESCRIPTION(MOD_DESC);
+MODULE_LICENSE("GPL");
+module_param(debug, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(debug, "Debug messages: 0=no, 1=yes (default: no)");
+
+static void delete_context(struct sasem_context *context)
+{
+	usb_free_urb(context->tx_urb);  /* VFD */
+	usb_free_urb(context->rx_urb);  /* IR */
+	lirc_buffer_free(context->driver->rbuf);
+	kfree(context->driver->rbuf);
+	kfree(context->driver);
+	kfree(context);
+
+	if (debug)
+		printk(KERN_INFO "%s: context deleted\n", __func__);
+}
+
+static void deregister_from_lirc(struct sasem_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 "Deregistered Sasem driver (minor:%d)\n",
+		       minor);
+
+}
+
+/**
+ * Called when the VFD device (e.g. /dev/usb/lcd)
+ * is opened by the application.
+ */
+static int vfd_open(struct inode *inode, struct file *file)
+{
+	struct usb_interface *interface;
+	struct sasem_context *context = NULL;
+	int subminor;
+	int retval = 0;
+
+	/* prevent races with disconnect */
+	mutex_lock(&disconnect_lock);
+
+	subminor = iminor(inode);
+	interface = usb_find_interface(&sasem_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->vfd_isopen) {
+		err("%s: VFD port is already open", __func__);
+		retval = -EBUSY;
+	} else {
+		context->vfd_isopen = 1;
+		file->private_data = context;
+		printk(KERN_INFO "VFD port opened\n");
+	}
+
+	mutex_unlock(&context->ctx_lock);
+
+exit:
+	mutex_unlock(&disconnect_lock);
+	return retval;
+}
+
+/**
+ * Called when the VFD device (e.g. /dev/usb/lcd)
+ * is closed by the application.
+ */
+static long vfd_ioctl(struct file *file, unsigned cmd, unsigned long arg)
+{
+	struct sasem_context *context = NULL;
+
+	context = (struct sasem_context *) file->private_data;
+
+	if (!context) {
+		err("%s: no context for device", __func__);
+		return -ENODEV;
+	}
+
+	mutex_lock(&context->ctx_lock);
+
+	switch (cmd) {
+	case IOCTL_LCD_CONTRAST:
+		if (arg > 1000)
+			arg = 1000;
+		context->vfd_contrast = (unsigned int)arg;
+		break;
+	default:
+		printk(KERN_INFO "Unknown IOCTL command\n");
+		mutex_unlock(&context->ctx_lock);
+		return -ENOIOCTLCMD;  /* not supported */
+	}
+
+	mutex_unlock(&context->ctx_lock);
+	return 0;
+}
+
+/**
+ * Called when the VFD device (e.g. /dev/usb/lcd)
+ * is closed by the application.
+ */
+static int vfd_close(struct inode *inode, struct file *file)
+{
+	struct sasem_context *context = NULL;
+	int retval = 0;
+
+	context = (struct sasem_context *) file->private_data;
+
+	if (!context) {
+		err("%s: no context for device", __func__);
+		return -ENODEV;
+	}
+
+	mutex_lock(&context->ctx_lock);
+
+	if (!context->vfd_isopen) {
+		err("%s: VFD is not open", __func__);
+		retval = -EIO;
+	} else {
+		context->vfd_isopen = 0;
+		printk(KERN_INFO "VFD 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);
+			delete_context(context);
+			return retval;
+		}
+	}
+
+	mutex_unlock(&context->ctx_lock);
+	return retval;
+}
+
+/**
+ * Sends a packet to the VFD.
+ */
+static int send_packet(struct sasem_context *context)
+{
+	unsigned int pipe;
+	int interval = 0;
+	int retval = 0;
+
+	pipe = usb_sndintpipe(context->dev,
+			context->tx_endpoint->bEndpointAddress);
+	interval = context->tx_endpoint->bInterval;
+
+	usb_fill_int_urb(context->tx_urb, context->dev, 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);
+		wait_for_completion(&context->tx.finished);
+		mutex_lock(&context->ctx_lock);
+
+		retval = context->tx.status;
+		if (retval)
+			err("%s: packet tx failed (%d)", __func__, retval);
+	}
+
+	return retval;
+}
+
+/**
+ * Writes data to the VFD.  The Sasem VFD is 2x16 characters
+ * and requires data in 9 consecutive USB interrupt packets,
+ * each packet carrying 8 bytes.
+ */
+static ssize_t vfd_write(struct file *file, const char *buf,
+				size_t n_bytes, loff_t *pos)
+{
+	int i;
+	int retval = 0;
+	struct sasem_context *context;
+	int *data_buf;
+
+	context = (struct sasem_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 Sasem device present", __func__);
+		retval = -ENODEV;
+		goto exit;
+	}
+
+	if (n_bytes <= 0 || n_bytes > SASEM_DATA_BUF_SZ) {
+		err("%s: invalid payload size", __func__);
+		retval = -EINVAL;
+		goto exit;
+	}
+
+	data_buf = memdup_user(buf, n_bytes);
+	if (PTR_ERR(data_buf))
+		return PTR_ERR(data_buf);
+
+	memcpy(context->tx.data_buf, data_buf, n_bytes);
+
+	/* Pad with spaces */
+	for (i = n_bytes; i < SASEM_DATA_BUF_SZ; ++i)
+		context->tx.data_buf[i] = ' ';
+
+	/* Nine 8 byte packets to be sent */
+	/* NOTE: "\x07\x01\0\0\0\0\0\0" or "\x0c\0\0\0\0\0\0\0"
+	 *       will clear the VFD */
+	for (i = 0; i < 9; i++) {
+		switch (i) {
+		case 0:
+			memcpy(context->usb_tx_buf, "\x07\0\0\0\0\0\0\0", 8);
+			context->usb_tx_buf[1] = (context->vfd_contrast) ?
+				(0x2B - (context->vfd_contrast - 1) / 250)
+				: 0x2B;
+			break;
+		case 1:
+			memcpy(context->usb_tx_buf, "\x09\x01\0\0\0\0\0\0", 8);
+			break;
+		case 2:
+			memcpy(context->usb_tx_buf, "\x0b\x01\0\0\0\0\0\0", 8);
+			break;
+		case 3:
+			memcpy(context->usb_tx_buf, context->tx.data_buf, 8);
+			break;
+		case 4:
+			memcpy(context->usb_tx_buf,
+			       context->tx.data_buf + 8, 8);
+			break;
+		case 5:
+			memcpy(context->usb_tx_buf, "\x09\x01\0\0\0\0\0\0", 8);
+			break;
+		case 6:
+			memcpy(context->usb_tx_buf, "\x0b\x02\0\0\0\0\0\0", 8);
+			break;
+		case 7:
+			memcpy(context->usb_tx_buf,
+			       context->tx.data_buf + 16, 8);
+			break;
+		case 8:
+			memcpy(context->usb_tx_buf,
+			       context->tx.data_buf + 24, 8);
+			break;
+		}
+		retval = send_packet(context);
+		if (retval) {
+
+			err("%s: send packet failed for packet #%d",
+					__func__, i);
+			goto exit;
+		}
+	}
+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 sasem_context *context;
+
+	if (!urb)
+		return;
+	context = (struct sasem_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 sasem_context *context;
+
+	/* prevent races with disconnect */
+	mutex_lock(&disconnect_lock);
+
+	context = (struct sasem_context *) data;
+
+	mutex_lock(&context->ctx_lock);
+
+	if (context->ir_isopen) {
+		err("%s: IR port is already open", __func__);
+		retval = -EBUSY;
+		goto exit;
+	}
+
+	usb_fill_int_urb(context->rx_urb, context->dev,
+		usb_rcvintpipe(context->dev,
+				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 ir_open (%d)",
+		    __func__, retval);
+	else {
+		context->ir_isopen = 1;
+		printk(KERN_INFO "IR port opened\n");
+	}
+
+exit:
+	mutex_unlock(&context->ctx_lock);
+
+	mutex_unlock(&disconnect_lock);
+	return 0;
+}
+
+/**
+ * Called by lirc_dev when the application closes /dev/lirc
+ */
+static void ir_close(void *data)
+{
+	struct sasem_context *context;
+
+	context = (struct sasem_context *)data;
+	if (!context) {
+		err("%s: no context for device", __func__);
+		return;
+	}
+
+	mutex_lock(&context->ctx_lock);
+
+	usb_kill_urb(context->rx_urb);
+	context->ir_isopen = 0;
+	printk(KERN_INFO "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->vfd_isopen) {
+
+			mutex_unlock(&context->ctx_lock);
+			delete_context(context);
+			return;
+		}
+		/* If VFD port is open, context will be deleted by vfd_close */
+	}
+
+	mutex_unlock(&context->ctx_lock);
+	return;
+}
+
+/**
+ * Process the incoming packet
+ */
+static void incoming_packet(struct sasem_context *context,
+				   struct urb *urb)
+{
+	int len = urb->actual_length;
+	unsigned char *buf = urb->transfer_buffer;
+	long ms;
+	struct timeval tv;
+
+	if (len != 8) {
+		printk(KERN_WARNING "%s: invalid incoming packet size (%d)\n",
+		     __func__, len);
+		return;
+	}
+
+#ifdef DEBUG
+	int i;
+	for (i = 0; i < 8; ++i)
+		printk(KERN_INFO "%02x ", buf[i]);
+	printk(KERN_INFO "\n");
+#endif
+
+	/*
+	 * Lirc could deal with the repeat code, but we really need to block it
+	 * if it arrives too late.  Otherwise we could repeat the wrong code.
+	 */
+
+	/* get the time since the last button press */
+	do_gettimeofday(&tv);
+	ms = (tv.tv_sec - context->presstime.tv_sec) * 1000 +
+	     (tv.tv_usec - context->presstime.tv_usec) / 1000;
+
+	if (memcmp(buf, "\x08\0\0\0\0\0\0\0", 8) == 0) {
+		/*
+		 * the repeat code is being sent, so we copy
+		 * the old code to LIRC
+		 */
+
+		/*
+		 * NOTE: Only if the last code was less than 250ms ago
+		 * - no one should be able to push another (undetected) button
+		 *   in that time and then get a false repeat of the previous
+		 *   press but it is long enough for a genuine repeat
+		 */
+		if ((ms < 250) && (context->codesaved != 0)) {
+			memcpy(buf, &context->lastcode, 8);
+			context->presstime.tv_sec = tv.tv_sec;
+			context->presstime.tv_usec = tv.tv_usec;
+		}
+	} else {
+		/* save the current valid code for repeats */
+		memcpy(&context->lastcode, buf, 8);
+		/*
+		 * set flag to signal a valid code was save;
+		 * just for safety reasons
+		 */
+		context->codesaved = 1;
+		context->presstime.tv_sec = tv.tv_sec;
+		context->presstime.tv_usec = tv.tv_usec;
+	}
+
+	lirc_buffer_write(context->driver->rbuf, buf);
+	wake_up(&context->driver->rbuf->wait_poll);
+}
+
+/**
+ * Callback function for USB core API: receive data
+ */
+static void usb_rx_callback(struct urb *urb)
+{
+	struct sasem_context *context;
+
+	if (!urb)
+		return;
+	context = (struct sasem_context *) urb->context;
+	if (!context)
+		return;
+
+	switch (urb->status) {
+
+	case -ENOENT:		/* usbcore unlink successful! */
+		return;
+
+	case 0:
+		if (context->ir_isopen)
+			incoming_packet(context, urb);
+		break;
+
+	default:
+		printk(KERN_WARNING "%s: status (%d): ignored",
+			 __func__, urb->status);
+		break;
+	}
+
+	usb_submit_urb(context->rx_urb, GFP_ATOMIC);
+	return;
+}
+
+
+
+/**
+ * Callback function for USB core API: Probe
+ */
+static int sasem_probe(struct usb_interface *interface,
+			const struct usb_device_id *id)
+{
+	struct usb_device *dev = 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;
+	int lirc_minor = 0;
+	int num_endpoints;
+	int retval = 0;
+	int vfd_ep_found;
+	int ir_ep_found;
+	int alloc_status;
+	struct sasem_context *context = NULL;
+	int i;
+
+	printk(KERN_INFO "%s: found Sasem device\n", __func__);
+
+
+	dev = usb_get_dev(interface_to_usbdev(interface));
+	iface_desc = interface->cur_altsetting;
+	num_endpoints = iface_desc->desc.bNumEndpoints;
+
+	/*
+	 * Scan the endpoint list and set:
+	 *	first input endpoint = IR endpoint
+	 *	first output endpoint = VFD endpoint
+	 */
+
+	ir_ep_found = 0;
+	vfd_ep_found = 0;
+
+	for (i = 0; i < num_endpoints && !(ir_ep_found && vfd_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;
+			if (debug)
+				printk(KERN_INFO "%s: found IR endpoint\n",
+				       __func__);
+
+		} else if (!vfd_ep_found &&
+			ep_dir == USB_DIR_OUT &&
+			ep_type == USB_ENDPOINT_XFER_INT) {
+
+			tx_endpoint = ep;
+			vfd_ep_found = 1;
+			if (debug)
+				printk(KERN_INFO "%s: found VFD endpoint\n",
+				       __func__);
+		}
+	}
+
+	/* Input endpoint is mandatory */
+	if (!ir_ep_found) {
+
+		err("%s: no valid input (IR) endpoint found.", __func__);
+		retval = -ENODEV;
+		goto exit;
+	}
+
+	if (!vfd_ep_found)
+		printk(KERN_INFO "%s: no valid output (VFD) endpoint found.\n",
+		       __func__);
+
+
+	/* Allocate memory */
+	alloc_status = 0;
+
+	context = kzalloc(sizeof(struct sasem_context), GFP_KERNEL);
+	if (!context) {
+		err("%s: kzalloc failed for context", __func__);
+		alloc_status = 1;
+		goto alloc_status_switch;
+	}
+	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;
+	}
+	if (vfd_ep_found) {
+		tx_urb = usb_alloc_urb(0, GFP_KERNEL);
+		if (!tx_urb) {
+			err("%s: usb_alloc_urb failed for VFD urb",
+			    __func__);
+			alloc_status = 6;
+			goto alloc_status_switch;
+		}
+	}
+
+	mutex_init(&context->ctx_lock);
+
+	strcpy(driver->name, MOD_NAME);
+	driver->minor = -1;
+	driver->code_length = 64;
+	driver->sample_rate = 0;
+	driver->features = LIRC_CAN_REC_LIRCCODE;
+	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);
+
+	lirc_minor = lirc_register_driver(driver);
+	if (lirc_minor < 0) {
+		err("%s: lirc_register_driver failed", __func__);
+		alloc_status = 7;
+		mutex_unlock(&context->ctx_lock);
+	} else
+		printk(KERN_INFO "%s: Registered Sasem driver (minor:%d)\n",
+			__func__, lirc_minor);
+
+alloc_status_switch:
+
+	switch (alloc_status) {
+
+	case 7:
+		if (vfd_ep_found)
+			usb_free_urb(tx_urb);
+	case 6:
+		usb_free_urb(rx_urb);
+	case 5:
+		lirc_buffer_free(rbuf);
+	case 4:
+		kfree(rbuf);
+	case 3:
+		kfree(driver);
+	case 2:
+		kfree(context);
+		context = NULL;
+	case 1:
+		retval = -ENOMEM;
+		goto exit;
+	}
+
+	/* Needed while unregistering! */
+	driver->minor = lirc_minor;
+
+	context->dev = dev;
+	context->dev_present = 1;
+	context->rx_endpoint = rx_endpoint;
+	context->rx_urb = rx_urb;
+	if (vfd_ep_found) {
+		context->tx_endpoint = tx_endpoint;
+		context->tx_urb = tx_urb;
+		context->vfd_contrast = 1000;   /* range 0 - 1000 */
+	}
+	context->driver = driver;
+
+	usb_set_intfdata(interface, context);
+
+	if (vfd_ep_found) {
+
+		if (debug)
+			printk(KERN_INFO "Registering VFD with sysfs\n");
+		if (usb_register_dev(interface, &sasem_class))
+			/* Not a fatal error, so ignore */
+			printk(KERN_INFO "%s: could not get a minor number "
+			       "for VFD\n", __func__);
+	}
+
+	printk(KERN_INFO "%s: Sasem device on usb<%d:%d> initialized\n",
+			__func__, dev->bus->busnum, dev->devnum);
+
+	mutex_unlock(&context->ctx_lock);
+exit:
+	return retval;
+}
+
+/**
+ * Callback function for USB core API: disonnect
+ */
+static void sasem_disconnect(struct usb_interface *interface)
+{
+	struct sasem_context *context;
+
+	/* prevent races with ir_open()/vfd_open() */
+	mutex_lock(&disconnect_lock);
+
+	context = usb_get_intfdata(interface);
+	mutex_lock(&context->ctx_lock);
+
+	printk(KERN_INFO "%s: Sasem device disconnected\n", __func__);
+
+	usb_set_intfdata(interface, NULL);
+	context->dev_present = 0;
+
+	/* Stop reception */
+	usb_kill_urb(context->rx_urb);
+
+	/* Abort ongoing write */
+	if (atomic_read(&context->tx.busy)) {
+
+		usb_kill_urb(context->tx_urb);
+		wait_for_completion(&context->tx.finished);
+	}
+
+	/* De-register from lirc_dev if IR port is not open */
+	if (!context->ir_isopen)
+		deregister_from_lirc(context);
+
+	usb_deregister_dev(interface, &sasem_class);
+
+	mutex_unlock(&context->ctx_lock);
+
+	if (!context->ir_isopen && !context->vfd_isopen)
+		delete_context(context);
+
+	mutex_unlock(&disconnect_lock);
+}
+
+static int __init sasem_init(void)
+{
+	int rc;
+
+	printk(KERN_INFO MOD_DESC ", v" MOD_VERSION "\n");
+	printk(KERN_INFO MOD_AUTHOR "\n");
+
+	rc = usb_register(&sasem_driver);
+	if (rc < 0) {
+		err("%s: usb register failed (%d)", __func__, rc);
+		return -ENODEV;
+	}
+	return 0;
+}
+
+static void __exit sasem_exit(void)
+{
+	usb_deregister(&sasem_driver);
+	printk(KERN_INFO "module removed. Goodbye!\n");
+}
+
+
+module_init(sasem_init);
+module_exit(sasem_exit);