]> git.karo-electronics.de Git - linux-beck.git/commitdiff
V4L/DVB: staging/lirc: add lirc_sasem driver
authorJarod Wilson <jarod@redhat.com>
Mon, 26 Jul 2010 23:31:11 +0000 (20:31 -0300)
committerMauro Carvalho Chehab <mchehab@redhat.com>
Mon, 2 Aug 2010 19:43:28 +0000 (16:43 -0300)
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
drivers/staging/lirc/lirc_sasem.c [new file with mode: 0644]

diff --git a/drivers/staging/lirc/lirc_sasem.c b/drivers/staging/lirc/lirc_sasem.c
new file mode 100644 (file)
index 0000000..9e516a1
--- /dev/null
@@ -0,0 +1,933 @@
+/*
+ * 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);