V4L/DVB: ir-core: add imon driver

This is a new driver for the SoundGraph iMON and Antec Veris IR/display
devices commonly found in many home theater pc cases and as after-market
case additions.

[mchehab@redhat.com: add KERN_CONT on line 2098 to shutup checkpatc.pl]
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/IR/Kconfig

@@ -36,3 +36,15 @@ config IR_RC6_DECODER
 	---help---
 	   Enable this option if you have an infrared remote control which
 	   uses the RC6 protocol, and you need software decoding support.
+
+config IR_IMON
+	tristate "SoundGraph iMON Receiver and Display"
+	depends on USB_ARCH_HAS_HCD
+	depends on IR_CORE
+	select USB
+	---help---
+	   Say Y here if you want to use a SoundGraph iMON (aka Antec Veris)
+	   IR Receiver and/or LCD/VFD/VGA display.
+
+	   To compile this driver as a module, choose M here: the
+	   module will be called imon.

drivers/media/IR/Makefile

@@ -8,3 +8,6 @@ obj-$(CONFIG_VIDEO_IR) += ir-common.o
 obj-$(CONFIG_IR_NEC_DECODER) += ir-nec-decoder.o
 obj-$(CONFIG_IR_RC5_DECODER) += ir-rc5-decoder.o
 obj-$(CONFIG_IR_RC6_DECODER) += ir-rc6-decoder.o
+
+# stand-alone IR receivers/transmitters
+obj-$(CONFIG_IR_IMON) += imon.o

drivers/media/IR/imon.c

+/*
+ *   imon.c:	input and display driver for SoundGraph iMON IR/VFD/LCD
+ *
+ *   Copyright(C) 2009  Jarod Wilson <jarod@wilsonet.com>
+ *   Portions based on the original lirc_imon driver,
+ *	Copyright(C) 2004  Venky Raju(dev@venky.ws)
+ *
+ *   Huge thanks to R. Geoff Newbury for invaluable debugging on the
+ *   0xffdc iMON devices, and for sending me one to hack on, without
+ *   which the support for them wouldn't be nearly as good. Thanks
+ *   also to the numerous 0xffdc device owners that tested auto-config
+ *   support for me and provided debug dumps from their devices.
+ *
+ *   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/input.h>
+#include <linux/usb.h>
+#include <linux/usb/input.h>
+#include <media/ir-core.h>
+
+#include <linux/time.h>
+#include <linux/timer.h>
+
+#define MOD_AUTHOR	"Jarod Wilson <jarod@wilsonet.com>"
+#define MOD_DESC	"Driver for SoundGraph iMON MultiMedia IR/Display"
+#define MOD_NAME	"imon"
+#define MOD_VERSION	"0.9.1"
+
+#define DISPLAY_MINOR_BASE	144
+#define DEVICE_NAME	"lcd%d"
+
+#define BUF_CHUNK_SIZE	8
+#define BUF_SIZE	128
+
+#define BIT_DURATION	250	/* each bit received is 250us */
+
+#define IMON_CLOCK_ENABLE_PACKETS	2
+#define IMON_KEY_RELEASE_OFFSET		1000
+
+/*** 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_intf0(struct urb *urb);
+static void usb_rx_callback_intf1(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);
+
+/* LCD file_operations override function prototypes */
+static ssize_t lcd_write(struct file *file, const char *buf,
+			 size_t n_bytes, loff_t *pos);
+
+/*** G L O B A L S ***/
+
+struct imon_context {
+	struct device *dev;
+	struct ir_dev_props *props;
+	struct ir_input_dev *ir;
+	/* Newer devices have two interfaces */
+	struct usb_device *usbdev_intf0;
+	struct usb_device *usbdev_intf1;
+
+	bool display_supported;		/* not all controllers do */
+	bool display_isopen;		/* display port has been opened */
+	bool rf_isassociating;		/* RF remote associating */
+	bool dev_present_intf0;		/* USB device presence, interface 0 */
+	bool dev_present_intf1;		/* USB device presence, interface 1 */
+
+	struct mutex lock;		/* to lock this object */
+	wait_queue_head_t remove_ok;	/* For unexpected USB disconnects */
+
+	struct usb_endpoint_descriptor *rx_endpoint_intf0;
+	struct usb_endpoint_descriptor *rx_endpoint_intf1;
+	struct usb_endpoint_descriptor *tx_endpoint;
+	struct urb *rx_urb_intf0;
+	struct urb *rx_urb_intf1;
+	struct urb *tx_urb;
+	bool tx_control;
+	unsigned char usb_rx_buf[8];
+	unsigned char usb_tx_buf[8];
+
+	struct tx_t {
+		unsigned char data_buf[35];	/* user data buffer */
+		struct completion finished;	/* wait for write to finish */
+		bool busy;			/* write in progress */
+		int status;			/* status of tx completion */
+	} tx;
+
+	u16 vendor;			/* usb vendor ID */
+	u16 product;			/* usb product ID */
+
+	struct input_dev *idev;		/* input device for remote */
+	struct input_dev *touch;	/* input device for touchscreen */
+
+	u32 kc;				/* current input keycode */
+	u32 last_keycode;		/* last reported input keycode */
+	u8 ir_protocol;			/* iMON or MCE (RC6) IR protocol? */
+	u8 ir_proto_mask;		/* supported IR protocol mask */
+	u8 mce_toggle_bit;		/* last mce toggle bit */
+	bool release_code;		/* some keys send a release code */
+
+	u8 display_type;		/* store the display type */
+	bool pad_mouse;			/* toggle kbd(0)/mouse(1) mode */
+
+	char name_idev[128];		/* input device name */
+	char phys_idev[64];		/* input device phys path */
+	struct timer_list itimer;	/* input device timer, need for rc6 */
+
+	char name_touch[128];		/* touch screen name */
+	char phys_touch[64];		/* touch screen phys path */
+	struct timer_list ttimer;	/* touch screen timer */
+	int touch_x;			/* x coordinate on touchscreen */
+	int touch_y;			/* y coordinate on touchscreen */
+};
+
+#define TOUCH_TIMEOUT	(HZ/30)
+#define MCE_TIMEOUT_MS	200
+
+/* vfd character device file operations */
+static const struct file_operations vfd_fops = {
+	.owner		= THIS_MODULE,
+	.open		= &display_open,
+	.write		= &vfd_write,
+	.release	= &display_close
+};
+
+/* lcd character device file operations */
+static const struct file_operations lcd_fops = {
+	.owner		= THIS_MODULE,
+	.open		= &display_open,
+	.write		= &lcd_write,
+	.release	= &display_close
+};
+
+enum {
+	IMON_DISPLAY_TYPE_AUTO = 0,
+	IMON_DISPLAY_TYPE_VFD  = 1,
+	IMON_DISPLAY_TYPE_LCD  = 2,
+	IMON_DISPLAY_TYPE_VGA  = 3,
+	IMON_DISPLAY_TYPE_NONE = 4,
+};
+
+enum {
+	IMON_IR_PROTOCOL_AUTO       = 0x0,
+	IMON_IR_PROTOCOL_MCE        = 0x1,
+	IMON_IR_PROTOCOL_IMON       = 0x2,
+	IMON_IR_PROTOCOL_IMON_NOPAD = 0x4,
+};
+
+enum {
+	IMON_IR_PROTO_MASK_NONE = 0x0,
+	IMON_IR_PROTO_MASK_MCE  = IMON_IR_PROTOCOL_MCE,
+	IMON_IR_PROTO_MASK_IMON = IMON_IR_PROTOCOL_IMON |
+				  IMON_IR_PROTOCOL_IMON_NOPAD,
+};
+
+enum {
+	IMON_KEY_IMON	= 0,
+	IMON_KEY_MCE	= 1,
+	IMON_KEY_PANEL	= 2,
+};
+
+/*
+ * 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). This driver only supports
+ * the ffdc and later devices, which do onboard decoding.
+ */
+static struct usb_device_id imon_usb_id_table[] = {
+	/*
+	 * Several devices with this same device ID, all use iMON_PAD.inf
+	 * SoundGraph iMON PAD (IR & VFD)
+	 * SoundGraph iMON PAD (IR & LCD)
+	 * SoundGraph iMON Knob (IR only)
+	 */
+	{ USB_DEVICE(0x15c2, 0xffdc) },
+
+	/*
+	 * Newer devices, all driven by the latest iMON Windows driver, full
+	 * list of device IDs extracted via 'strings Setup/data1.hdr |grep 15c2'
+	 * Need user input to fill in details on unknown devices.
+	 */
+	/* SoundGraph iMON OEM Touch LCD (IR & 7" VGA LCD) */
+	{ USB_DEVICE(0x15c2, 0x0034) },
+	/* SoundGraph iMON OEM Touch LCD (IR & 4.3" VGA LCD) */
+	{ USB_DEVICE(0x15c2, 0x0035) },
+	/* SoundGraph iMON OEM VFD (IR & VFD) */
+	{ USB_DEVICE(0x15c2, 0x0036) },
+	/* device specifics unknown */
+	{ USB_DEVICE(0x15c2, 0x0037) },
+	/* SoundGraph iMON OEM LCD (IR & LCD) */
+	{ USB_DEVICE(0x15c2, 0x0038) },
+	/* SoundGraph iMON UltraBay (IR & LCD) */
+	{ USB_DEVICE(0x15c2, 0x0039) },
+	/* device specifics unknown */
+	{ USB_DEVICE(0x15c2, 0x003a) },
+	/* device specifics unknown */
+	{ USB_DEVICE(0x15c2, 0x003b) },
+	/* SoundGraph iMON OEM Inside (IR only) */
+	{ USB_DEVICE(0x15c2, 0x003c) },
+	/* device specifics unknown */
+	{ USB_DEVICE(0x15c2, 0x003d) },
+	/* device specifics unknown */
+	{ USB_DEVICE(0x15c2, 0x003e) },
+	/* device specifics unknown */
+	{ USB_DEVICE(0x15c2, 0x003f) },
+	/* device specifics unknown */
+	{ USB_DEVICE(0x15c2, 0x0040) },
+	/* SoundGraph iMON MINI (IR only) */
+	{ USB_DEVICE(0x15c2, 0x0041) },
+	/* Antec Veris Multimedia Station EZ External (IR only) */
+	{ USB_DEVICE(0x15c2, 0x0042) },
+	/* Antec Veris Multimedia Station Basic Internal (IR only) */
+	{ USB_DEVICE(0x15c2, 0x0043) },
+	/* Antec Veris Multimedia Station Elite (IR & VFD) */
+	{ USB_DEVICE(0x15c2, 0x0044) },
+	/* Antec Veris Multimedia Station Premiere (IR & LCD) */
+	{ USB_DEVICE(0x15c2, 0x0045) },
+	/* device specifics unknown */
+	{ USB_DEVICE(0x15c2, 0x0046) },
+	{}
+};
+
+/* 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_vfd_class = {
+	.name		= DEVICE_NAME,
+	.fops		= &vfd_fops,
+	.minor_base	= DISPLAY_MINOR_BASE,
+};
+
+static struct usb_class_driver imon_lcd_class = {
+	.name		= DEVICE_NAME,
+	.fops		= &lcd_fops,
+	.minor_base	= DISPLAY_MINOR_BASE,
+};
+
+/* imon receiver front panel/knob key table */
+static const struct {
+	u64 hw_code;
+	u32 keycode;
+} imon_panel_key_table[] = {
+	{ 0x000000000f00ffee, KEY_PROG1 }, /* Go */
+	{ 0x000000001f00ffee, KEY_AUDIO },
+	{ 0x000000002000ffee, KEY_VIDEO },
+	{ 0x000000002100ffee, KEY_CAMERA },
+	{ 0x000000002700ffee, KEY_DVD },
+	{ 0x000000002300ffee, KEY_TV },
+	{ 0x000000000500ffee, KEY_PREVIOUS },
+	{ 0x000000000700ffee, KEY_REWIND },
+	{ 0x000000000400ffee, KEY_STOP },
+	{ 0x000000003c00ffee, KEY_PLAYPAUSE },
+	{ 0x000000000800ffee, KEY_FASTFORWARD },
+	{ 0x000000000600ffee, KEY_NEXT },
+	{ 0x000000010000ffee, KEY_RIGHT },
+	{ 0x000001000000ffee, KEY_LEFT },
+	{ 0x000000003d00ffee, KEY_SELECT },
+	{ 0x000100000000ffee, KEY_VOLUMEUP },
+	{ 0x010000000000ffee, KEY_VOLUMEDOWN },
+	{ 0x000000000100ffee, KEY_MUTE },
+	/* iMON Knob values */
+	{ 0x000100ffffffffee, KEY_VOLUMEUP },
+	{ 0x010000ffffffffee, KEY_VOLUMEDOWN },
+	{ 0x000008ffffffffee, KEY_MUTE },
+};
+
+/* to prevent races between open() and disconnect(), probing, etc */
+static DEFINE_MUTEX(driver_lock);
+
+/* Module bookkeeping bits */
+MODULE_AUTHOR(MOD_AUTHOR);
+MODULE_DESCRIPTION(MOD_DESC);
+MODULE_VERSION(MOD_VERSION);
+MODULE_LICENSE("GPL");
+MODULE_DEVICE_TABLE(usb, imon_usb_id_table);
+
+static bool debug;
+module_param(debug, bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(debug, "Debug messages: 0=no, 1=yes(default: no)");
+
+/* lcd, vfd, vga or none? should be auto-detected, but can be overridden... */
+static int display_type;
+module_param(display_type, int, S_IRUGO);
+MODULE_PARM_DESC(display_type, "Type of attached display. 0=autodetect, "
+		 "1=vfd, 2=lcd, 3=vga, 4=none (default: autodetect)");
+
+/* IR protocol: native iMON, Windows MCE (RC-6), or iMON w/o PAD stabilize */
+static int ir_protocol;
+module_param(ir_protocol, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(ir_protocol, "Which IR protocol to use. 0=auto-detect, "
+		 "1=Windows Media Center Ed. (RC-6), 2=iMON native, "
+		 "4=iMON w/o PAD stabilize (default: auto-detect)");
+
+/*
+ * In certain use cases, mouse mode isn't really helpful, and could actually
+ * cause confusion, so allow disabling it when the IR device is open.
+ */
+static bool nomouse;
+module_param(nomouse, bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(nomouse, "Disable mouse input device mode when IR device is "
+		 "open. 0=don't disable, 1=disable. (default: don't disable)");
+
+/* threshold at which a pad push registers as an arrow key in kbd mode */
+static int pad_thresh;
+module_param(pad_thresh, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(pad_thresh, "Threshold at which a pad push registers as an "
+		 "arrow key in kbd mode (default: 28)");
+
+
+static void free_imon_context(struct imon_context *ictx)
+{
+	struct device *dev = ictx->dev;
+
+	usb_free_urb(ictx->tx_urb);
+	usb_free_urb(ictx->rx_urb_intf0);
+	usb_free_urb(ictx->rx_urb_intf1);
+	kfree(ictx);
+
+	dev_dbg(dev, "%s: iMON context freed\n", __func__);
+}
+
+/**
+ * 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 *ictx = 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;
+	}
+	ictx = usb_get_intfdata(interface);
+
+	if (!ictx) {
+		err("%s: no context found for minor %d", __func__, subminor);
+		retval = -ENODEV;
+		goto exit;
+	}
+
+	mutex_lock(&ictx->lock);
+
+	if (!ictx->display_supported) {
+		err("%s: display not supported by device", __func__);
+		retval = -ENODEV;
+	} else if (ictx->display_isopen) {
+		err("%s: display port is already open", __func__);
+		retval = -EBUSY;
+	} else {
+		ictx->display_isopen = 1;
+		file->private_data = ictx;
+		dev_dbg(ictx->dev, "display port opened\n");
+	}
+
+	mutex_unlock(&ictx->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 *ictx = NULL;
+	int retval = 0;
+
+	ictx = (struct imon_context *)file->private_data;
+
+	if (!ictx) {
+		err("%s: no context for device", __func__);
+		return -ENODEV;
+	}
+
+	mutex_lock(&ictx->lock);
+
+	if (!ictx->display_supported) {
+		err("%s: display not supported by device", __func__);
+		retval = -ENODEV;
+	} else if (!ictx->display_isopen) {
+		err("%s: display is not open", __func__);
+		retval = -EIO;
+	} else {
+		ictx->display_isopen = 0;
+		dev_dbg(ictx->dev, "display port closed\n");
+		if (!ictx->dev_present_intf0) {
+			/*
+			 * Device disconnected before close and IR port is not
+			 * open. If IR port is open, context will be deleted by
+			 * ir_close.
+			 */
+			mutex_unlock(&ictx->lock);
+			free_imon_context(ictx);
+			return retval;
+		}
+	}
+
+	mutex_unlock(&ictx->lock);
+	return retval;
+}
+
+/**
+ * Sends a packet to the device -- this function must be called
+ * with ictx->lock held.
+ */
+static int send_packet(struct imon_context *ictx)
+{
+	unsigned int pipe;
+	unsigned long timeout;
+	int interval = 0;
+	int retval = 0;
+	struct usb_ctrlrequest *control_req = NULL;
+
+	/* Check if we need to use control or interrupt urb */
+	if (!ictx->tx_control) {
+		pipe = usb_sndintpipe(ictx->usbdev_intf0,
+				      ictx->tx_endpoint->bEndpointAddress);
+		interval = ictx->tx_endpoint->bInterval;
+
+		usb_fill_int_urb(ictx->tx_urb, ictx->usbdev_intf0, pipe,
+				 ictx->usb_tx_buf,
+				 sizeof(ictx->usb_tx_buf),
+				 usb_tx_callback, ictx, interval);
+
+		ictx->tx_urb->actual_length = 0;
+	} else {
+		/* fill request into kmalloc'ed space: */
+		control_req = kmalloc(sizeof(struct usb_ctrlrequest),
+				      GFP_KERNEL);
+		if (control_req == NULL)
+			return -ENOMEM;
+
+		/* setup packet is '21 09 0200 0001 0008' */
+		control_req->bRequestType = 0x21;
+		control_req->bRequest = 0x09;
+		control_req->wValue = cpu_to_le16(0x0200);
+		control_req->wIndex = cpu_to_le16(0x0001);
+		control_req->wLength = cpu_to_le16(0x0008);
+
+		/* control pipe is endpoint 0x00 */
+		pipe = usb_sndctrlpipe(ictx->usbdev_intf0, 0);
+
+		/* build the control urb */
+		usb_fill_control_urb(ictx->tx_urb, ictx->usbdev_intf0,
+				     pipe, (unsigned char *)control_req,
+				     ictx->usb_tx_buf,
+				     sizeof(ictx->usb_tx_buf),
+				     usb_tx_callback, ictx);
+		ictx->tx_urb->actual_length = 0;
+	}
+
+	init_completion(&ictx->tx.finished);
+	ictx->tx.busy = 1;
+	smp_rmb(); /* ensure later readers know we're busy */
+
+	retval = usb_submit_urb(ictx->tx_urb, GFP_KERNEL);
+	if (retval) {
+		ictx->tx.busy = 0;
+		smp_rmb(); /* ensure later readers know we're not busy */
+		err("%s: error submitting urb(%d)", __func__, retval);
+	} else {
+		/* Wait for transmission to complete (or abort) */
+		mutex_unlock(&ictx->lock);
+		retval = wait_for_completion_interruptible(
+				&ictx->tx.finished);
+		if (retval)
+			err("%s: task interrupted", __func__);
+		mutex_lock(&ictx->lock);
+
+		retval = ictx->tx.status;
+		if (retval)
+			err("%s: packet tx failed (%d)", __func__, retval);
+	}
+
+	kfree(control_req);
+
+	/*
+	 * Induce a mandatory 5ms delay before returning, as otherwise,
+	 * send_packet can get called so rapidly as to overwhelm the device,
+	 * particularly on faster systems and/or those with quirky usb.
+	 */
+	timeout = msecs_to_jiffies(5);
+	set_current_state(TASK_UNINTERRUPTIBLE);
+	schedule_timeout(timeout);
+
+	return retval;
+}
+
+/**
+ * Sends an associate packet to the iMON 2.4G.
+ *
+ * This might not be such a good idea, since it has an id collision with
+ * some versions of the "IR & VFD" combo. The only way to determine if it
+ * is an RF version is to look at the product description string. (Which
+ * we currently do not fetch).
+ */
+static int send_associate_24g(struct imon_context *ictx)
+{
+	int retval;
+	const unsigned char packet[8] = { 0x01, 0x00, 0x00, 0x00,
+					  0x00, 0x00, 0x00, 0x20 };
+
+	if (!ictx) {
+		err("%s: no context for device", __func__);
+		return -ENODEV;
+	}
+
+	if (!ictx->dev_present_intf0) {
+		err("%s: no iMON device present", __func__);
+		return -ENODEV;
+	}
+
+	memcpy(ictx->usb_tx_buf, packet, sizeof(packet));
+	retval = send_packet(ictx);
+
+	return retval;
+}
+
+/**
+ * Sends packets to setup and show clock on iMON display
+ *
+ * Arguments: year - last 2 digits of year, month - 1..12,
+ * day - 1..31, dow - day of the week (0-Sun...6-Sat),
+ * hour - 0..23, minute - 0..59, second - 0..59
+ */
+static int send_set_imon_clock(struct imon_context *ictx,
+			       unsigned int year, unsigned int month,
+			       unsigned int day, unsigned int dow,
+			       unsigned int hour, unsigned int minute,
+			       unsigned int second)
+{
+	unsigned char clock_enable_pkt[IMON_CLOCK_ENABLE_PACKETS][8];
+	int retval = 0;
+	int i;
+
+	if (!ictx) {
+		err("%s: no context for device", __func__);
+		return -ENODEV;
+	}
+
+	switch (ictx->display_type) {
+	case IMON_DISPLAY_TYPE_LCD:
+		clock_enable_pkt[0][0] = 0x80;
+		clock_enable_pkt[0][1] = year;
+		clock_enable_pkt[0][2] = month-1;
+		clock_enable_pkt[0][3] = day;
+		clock_enable_pkt[0][4] = hour;
+		clock_enable_pkt[0][5] = minute;
+		clock_enable_pkt[0][6] = second;
+
+		clock_enable_pkt[1][0] = 0x80;
+		clock_enable_pkt[1][1] = 0;
+		clock_enable_pkt[1][2] = 0;
+		clock_enable_pkt[1][3] = 0;
+		clock_enable_pkt[1][4] = 0;
+		clock_enable_pkt[1][5] = 0;
+		clock_enable_pkt[1][6] = 0;
+
+		if (ictx->product == 0xffdc) {
+			clock_enable_pkt[0][7] = 0x50;
+			clock_enable_pkt[1][7] = 0x51;
+		} else {
+			clock_enable_pkt[0][7] = 0x88;
+			clock_enable_pkt[1][7] = 0x8a;
+		}
+
+		break;
+
+	case IMON_DISPLAY_TYPE_VFD:
+		clock_enable_pkt[0][0] = year;
+		clock_enable_pkt[0][1] = month-1;
+		clock_enable_pkt[0][2] = day;
+		clock_enable_pkt[0][3] = dow;
+		clock_enable_pkt[0][4] = hour;
+		clock_enable_pkt[0][5] = minute;
+		clock_enable_pkt[0][6] = second;
+		clock_enable_pkt[0][7] = 0x40;
+
+		clock_enable_pkt[1][0] = 0;
+		clock_enable_pkt[1][1] = 0;
+		clock_enable_pkt[1][2] = 1;
+		clock_enable_pkt[1][3] = 0;
+		clock_enable_pkt[1][4] = 0;
+		clock_enable_pkt[1][5] = 0;
+		clock_enable_pkt[1][6] = 0;
+		clock_enable_pkt[1][7] = 0x42;
+
+		break;
+
+	default:
+		return -ENODEV;
+	}
+
+	for (i = 0; i < IMON_CLOCK_ENABLE_PACKETS; i++) {
+		memcpy(ictx->usb_tx_buf, clock_enable_pkt[i], 8);
+		retval = send_packet(ictx);
+		if (retval) {
+			err("%s: send_packet failed for packet %d",
+			    __func__, i);
+			break;
+		}
+	}
+
+	return retval;
+}
+
+/**
+ * These are the sysfs functions to handle the association on the iMON 2.4G LT.
+ */
+static ssize_t show_associate_remote(struct device *d,
+				     struct device_attribute *attr,
+				     char *buf)
+{
+	struct imon_context *ictx = dev_get_drvdata(d);
+
+	if (!ictx)
+		return -ENODEV;
+
+	mutex_lock(&ictx->lock);
+	if (ictx->rf_isassociating)
+		strcpy(buf, "associating\n");
+	else
+		strcpy(buf, "closed\n");
+
+	dev_info(d, "Visit http://www.lirc.org/html/imon-24g.html for "
+		 "instructions on how to associate your iMON 2.4G DT/LT "
+		 "remote\n");
+	mutex_unlock(&ictx->lock);
+	return strlen(buf);
+}
+
+static ssize_t store_associate_remote(struct device *d,
+				      struct device_attribute *attr,
+				      const char *buf, size_t count)
+{
+	struct imon_context *ictx;
+
+	ictx = dev_get_drvdata(d);
+
+	if (!ictx)
+		return -ENODEV;
+
+	mutex_lock(&ictx->lock);
+	ictx->rf_isassociating = 1;
+	send_associate_24g(ictx);
+	mutex_unlock(&ictx->lock);
+
+	return count;
+}
+
+/**
+ * sysfs functions to control internal imon clock
+ */
+static ssize_t show_imon_clock(struct device *d,
+			       struct device_attribute *attr, char *buf)
+{
+	struct imon_context *ictx = dev_get_drvdata(d);
+	size_t len;
+
+	if (!ictx)
+		return -ENODEV;
+
+	mutex_lock(&ictx->lock);
+
+	if (!ictx->display_supported) {
+		len = snprintf(buf, PAGE_SIZE, "Not supported.");
+	} else {
+		len = snprintf(buf, PAGE_SIZE,
+			"To set the clock on your iMON display:\n"
+			"# date \"+%%y %%m %%d %%w %%H %%M %%S\" > imon_clock\n"
+			"%s", ictx->display_isopen ?
+			"\nNOTE: imon device must be closed\n" : "");
+	}
+
+	mutex_unlock(&ictx->lock);
+
+	return len;
+}
+
+static ssize_t store_imon_clock(struct device *d,
+				struct device_attribute *attr,
+				const char *buf, size_t count)
+{
+	struct imon_context *ictx = dev_get_drvdata(d);
+	ssize_t retval;
+	unsigned int year, month, day, dow, hour, minute, second;
+
+	if (!ictx)
+		return -ENODEV;
+
+	mutex_lock(&ictx->lock);
+
+	if (!ictx->display_supported) {
+		retval = -ENODEV;
+		goto exit;
+	} else if (ictx->display_isopen) {
+		retval = -EBUSY;
+		goto exit;
+	}
+
+	if (sscanf(buf, "%u %u %u %u %u %u %u",	&year, &month, &day, &dow,
+		   &hour, &minute, &second) != 7) {
+		retval = -EINVAL;
+		goto exit;
+	}
+
+	if ((month < 1 || month > 12) ||
+	    (day < 1 || day > 31) || (dow > 6) ||
+	    (hour > 23) || (minute > 59) || (second > 59)) {
+		retval = -EINVAL;
+		goto exit;
+	}
+
+	retval = send_set_imon_clock(ictx, year, month, day, dow,
+				     hour, minute, second);
+	if (retval)
+		goto exit;
+
+	retval = count;
+exit:
+	mutex_unlock(&ictx->lock);
+
+	return retval;
+}
+
+
+static DEVICE_ATTR(imon_clock, S_IWUSR | S_IRUGO, show_imon_clock,
+		   store_imon_clock);
+
+static DEVICE_ATTR(associate_remote, S_IWUSR | S_IRUGO, show_associate_remote,
+		   store_associate_remote);
+
+static struct attribute *imon_display_sysfs_entries[] = {
+	&dev_attr_imon_clock.attr,
+	NULL
+};
+
+static struct attribute_group imon_display_attribute_group = {
+	.attrs = imon_display_sysfs_entries
+};
+
+static struct attribute *imon_rf_sysfs_entries[] = {
+	&dev_attr_associate_remote.attr,
+	NULL
+};
+
+static struct attribute_group imon_rf_attribute_group = {
+	.attrs = imon_rf_sysfs_entries
+};
+
+/**
+ * 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 *ictx;
+	const unsigned char vfd_packet6[] = {
+		0x01, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF };
+
+	ictx = (struct imon_context *)file->private_data;
+	if (!ictx) {
+		err("%s: no context for device", __func__);
+		return -ENODEV;
+	}
+
+	mutex_lock(&ictx->lock);
+
+	if (!ictx->dev_present_intf0) {
+		err("%s: no iMON device present", __func__);
+		retval = -ENODEV;
+		goto exit;
+	}
+
+	if (n_bytes <= 0 || n_bytes > 32) {
+		err("%s: invalid payload size", __func__);
+		retval = -EINVAL;
+		goto exit;
+	}
+
+	if (copy_from_user(ictx->tx.data_buf, buf, n_bytes)) {
+		retval = -EFAULT;
+		goto exit;
+	}
+
+	/* Pad with spaces */
+	for (i = n_bytes; i < 32; ++i)
+		ictx->tx.data_buf[i] = ' ';
+
+	for (i = 32; i < 35; ++i)
+		ictx->tx.data_buf[i] = 0xFF;
+
+	offset = 0;
+	seq = 0;
+
+	do {
+		memcpy(ictx->usb_tx_buf, ictx->tx.data_buf + offset, 7);
+		ictx->usb_tx_buf[7] = (unsigned char) seq;
+
+		retval = send_packet(ictx);
+		if (retval) {
+			err("%s: send packet failed for packet #%d",
+					__func__, seq/2);
+			goto exit;
+		} else {
+			seq += 2;
+			offset += 7;
+		}
+
+	} while (offset < 35);
+
+	/* Send packet #6 */
+	memcpy(ictx->usb_tx_buf, &vfd_packet6, sizeof(vfd_packet6));
+	ictx->usb_tx_buf[7] = (unsigned char) seq;
+	retval = send_packet(ictx);
+	if (retval)
+		err("%s: send packet failed for packet #%d",
+		    __func__, seq / 2);
+
+exit:
+	mutex_unlock(&ictx->lock);
+
+	return (!retval) ? n_bytes : retval;
+}
+
+/**
+ * Writes data to the LCD.  The iMON OEM LCD screen expects 8-byte
+ * packets. We accept data as 16 hexadecimal digits, followed by a
+ * newline (to make it easy to drive the device from a command-line
+ * -- even though the actual binary data is a bit complicated).
+ *
+ * The device itself is not a "traditional" text-mode display. It's
+ * actually a 16x96 pixel bitmap display. That means if you want to
+ * display text, you've got to have your own "font" and translate the
+ * text into bitmaps for display. This is really flexible (you can
+ * display whatever diacritics you need, and so on), but it's also
+ * a lot more complicated than most LCDs...
+ */
+static ssize_t lcd_write(struct file *file, const char *buf,
+			 size_t n_bytes, loff_t *pos)
+{
+	int retval = 0;
+	struct imon_context *ictx;
+
+	ictx = (struct imon_context *)file->private_data;
+	if (!ictx) {
+		err("%s: no context for device", __func__);
+		return -ENODEV;
+	}
+
+	mutex_lock(&ictx->lock);
+
+	if (!ictx->display_supported) {
+		err("%s: no iMON display present", __func__);
+		retval = -ENODEV;
+		goto exit;
+	}
+
+	if (n_bytes != 8) {
+		err("%s: invalid payload size: %d (expecting 8)",
+		    __func__, (int) n_bytes);
+		retval = -EINVAL;
+		goto exit;
+	}
+
+	if (copy_from_user(ictx->usb_tx_buf, buf, 8)) {
+		retval = -EFAULT;
+		goto exit;
+	}
+
+	retval = send_packet(ictx);
+	if (retval) {
+		err("%s: send packet failed!", __func__);
+		goto exit;
+	} else {
+		dev_dbg(ictx->dev, "%s: write %d bytes to LCD\n",
+			__func__, (int) n_bytes);
+	}
+exit:
+	mutex_unlock(&ictx->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 *ictx;
+
+	if (!urb)
+		return;
+	ictx = (struct imon_context *)urb->context;
+	if (!ictx)
+		return;
+
+	ictx->tx.status = urb->status;
+
+	/* notify waiters that write has finished */
+	ictx->tx.busy = 0;
+	smp_rmb(); /* ensure later readers know we're not busy */
+	complete(&ictx->tx.finished);
+}
+
+/**
+ * mce/rc6 keypresses have no distinct release code, use timer
+ */
+static void imon_mce_timeout(unsigned long data)
+{
+	struct imon_context *ictx = (struct imon_context *)data;
+
+	input_report_key(ictx->idev, ictx->last_keycode, 0);
+	input_sync(ictx->idev);
+}
+
+/**
+ * report touchscreen input
+ */
+static void imon_touch_display_timeout(unsigned long data)
+{
+	struct imon_context *ictx = (struct imon_context *)data;
+
+	if (!ictx->display_type == IMON_DISPLAY_TYPE_VGA)
+		return;
+
+	input_report_abs(ictx->touch, ABS_X, ictx->touch_x);
+	input_report_abs(ictx->touch, ABS_Y, ictx->touch_y);
+	input_report_key(ictx->touch, BTN_TOUCH, 0x00);
+	input_sync(ictx->touch);
+}
+
+/**
+ * iMON IR receivers support two different signal sets -- those used by
+ * the iMON remotes, and those used by the Windows MCE remotes (which is
+ * really just RC-6), but only one or the other at a time, as the signals
+ * are decoded onboard the receiver.
+ */
+static void imon_set_ir_protocol(struct imon_context *ictx)
+{
+	int retval;
+	struct device *dev = ictx->dev;
+	unsigned char ir_proto_packet[] = {
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x86 };
+
+	if (ir_protocol && !(ir_protocol & ictx->ir_proto_mask))
+		dev_warn(dev, "Looks like you're trying to use an IR protocol "
+			 "this device does not support\n");
+
+	switch (ir_protocol) {
+	case IMON_IR_PROTOCOL_AUTO:
+		if (ictx->product == 0xffdc) {
+			if (ictx->ir_proto_mask & IMON_IR_PROTO_MASK_MCE) {
+				ir_proto_packet[0] = 0x01;
+				ictx->ir_protocol = IMON_IR_PROTOCOL_MCE;
+				ictx->pad_mouse = 0;
+				init_timer(&ictx->itimer);
+				ictx->itimer.data = (unsigned long)ictx;
+				ictx->itimer.function = imon_mce_timeout;
+			} else {
+				ictx->ir_protocol = IMON_IR_PROTOCOL_IMON;
+				ictx->pad_mouse = 1;
+			}
+		}
+		break;
+	case IMON_IR_PROTOCOL_MCE:
+		dev_dbg(dev, "Configuring IR receiver for MCE protocol\n");
+		ir_proto_packet[0] = 0x01;
+		ictx->ir_protocol = IMON_IR_PROTOCOL_MCE;
+		ictx->pad_mouse = 0;
+		init_timer(&ictx->itimer);
+		ictx->itimer.data = (unsigned long)ictx;
+		ictx->itimer.function = imon_mce_timeout;
+		break;
+	case IMON_IR_PROTOCOL_IMON:
+		dev_dbg(dev, "Configuring IR receiver for iMON protocol\n");
+		/* ir_proto_packet[0] = 0x00; // already the default */
+		ictx->ir_protocol = IMON_IR_PROTOCOL_IMON;
+		ictx->pad_mouse = 1;
+		break;
+	case IMON_IR_PROTOCOL_IMON_NOPAD:
+		dev_dbg(dev, "Configuring IR receiver for iMON protocol "
+			"without PAD stabilize function enabled\n");
+		/* ir_proto_packet[0] = 0x00; // already the default */
+		ictx->ir_protocol = IMON_IR_PROTOCOL_IMON_NOPAD;
+		ictx->pad_mouse = 0;
+		break;
+	default:
+		dev_info(dev, "%s: unknown IR protocol specified, will "
+			 "just default to iMON protocol\n", __func__);
+		ictx->ir_protocol = IMON_IR_PROTOCOL_IMON;
+		ictx->pad_mouse = 1;
+		break;
+	}
+
+	memcpy(ictx->usb_tx_buf, &ir_proto_packet, sizeof(ir_proto_packet));
+
+	retval = send_packet(ictx);
+	if (retval) {
+		dev_info(dev, "%s: failed to set IR protocol, falling back "
+			 "to standard iMON protocol mode\n", __func__);
+		ir_protocol = IMON_IR_PROTOCOL_IMON;
+		ictx->ir_protocol = IMON_IR_PROTOCOL_IMON;
+	}
+}
+
+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;
+}
+
+/**
+ * The directional pad behaves a bit differently, depending on whether this is
+ * one of the older ffdc devices or a newer device. Newer devices appear to
+ * have a higher resolution matrix for more precise mouse movement, but it
+ * makes things overly sensitive in keyboard mode, so we do some interesting
+ * contortions to make it less touchy. Older devices run through the same
+ * routine with shorter timeout and a smaller threshold.
+ */
+static int stabilize(int a, int b, u16 timeout, u16 threshold)
+{
+	struct timeval ct;
+	static struct timeval prev_time = {0, 0};
+	static struct timeval hit_time  = {0, 0};
+	static int x, y, prev_result, hits;
+	int result = 0;
+	int msec, msec_hit;
+
+	do_gettimeofday(&ct);
+	msec = tv2int(&ct, &prev_time);
+	msec_hit = tv2int(&ct, &hit_time);
+
+	if (msec > 100) {
+		x = 0;
+		y = 0;
+		hits = 0;
+	}
+
+	x += a;
+	y += b;
+
+	prev_time = ct;
+
+	if (abs(x) > threshold || abs(y) > threshold) {
+		if (abs(y) > abs(x))
+			result = (y > 0) ? 0x7F : 0x80;
+		else
+			result = (x > 0) ? 0x7F00 : 0x8000;
+
+		x = 0;
+		y = 0;
+
+		if (result == prev_result) {
+			hits++;
+
+			if (hits > 3) {
+				switch (result) {
+				case 0x7F:
+					y = 17 * threshold / 30;
+					break;
+				case 0x80:
+					y -= 17 * threshold / 30;
+					break;
+				case 0x7F00:
+					x = 17 * threshold / 30;
+					break;
+				case 0x8000:
+					x -= 17 * threshold / 30;
+					break;
+				}
+			}
+
+			if (hits == 2 && msec_hit < timeout) {
+				result = 0;
+				hits = 1;
+			}
+		} else {
+			prev_result = result;
+			hits = 1;
+			hit_time = ct;
+		}
+	}
+
+	return result;
+}
+
+static u32 imon_remote_key_lookup(struct imon_context *ictx, u32 hw_code)
+{
+	u32 scancode = be32_to_cpu(hw_code);
+	u32 keycode;
+	u32 release;
+	bool is_release_code = false;
+
+	/* Look for the initial press of a button */
+	keycode = ir_g_keycode_from_table(ictx->idev, scancode);
+
+	/* Look for the release of a button */
+	if (keycode == KEY_RESERVED) {
+		release = scancode & ~0x4000;
+		keycode = ir_g_keycode_from_table(ictx->idev, release);
+		if (keycode != KEY_RESERVED)
+			is_release_code = true;
+	}
+
+	ictx->release_code = is_release_code;
+
+	return keycode;
+}
+
+static u32 imon_mce_key_lookup(struct imon_context *ictx, u32 hw_code)
+{
+	u32 scancode = be32_to_cpu(hw_code);
+	u32 keycode;
+
+#define MCE_KEY_MASK 0x7000
+#define MCE_TOGGLE_BIT 0x8000
+
+	/*
+	 * On some receivers, mce keys decode to 0x8000f04xx and 0x8000f84xx
+	 * (the toggle bit flipping between alternating key presses), while
+	 * on other receivers, we see 0x8000f74xx and 0x8000ff4xx. To keep
+	 * the table trim, we always or in the bits to look up 0x8000ff4xx,
+	 * but we can't or them into all codes, as some keys are decoded in
+	 * a different way w/o the same use of the toggle bit...
+	 */
+	if ((scancode >> 24) & 0x80)
+		scancode = scancode | MCE_KEY_MASK | MCE_TOGGLE_BIT;
+
+	keycode = ir_g_keycode_from_table(ictx->idev, scancode);
+
+	return keycode;
+}
+
+static u32 imon_panel_key_lookup(u64 hw_code)
+{
+	int i;
+	u64 code = be64_to_cpu(hw_code);
+	u32 keycode;
+
+	for (i = 0; i < ARRAY_SIZE(imon_panel_key_table); i++)
+		if (imon_panel_key_table[i].hw_code == (code | 0xffee))
+			break;
+
+	keycode = imon_panel_key_table[i % IMON_KEY_RELEASE_OFFSET].keycode;
+
+	return keycode;
+}
+
+static bool imon_mouse_event(struct imon_context *ictx,
+			     unsigned char *buf, int len)
+{
+	char rel_x = 0x00, rel_y = 0x00;
+	u8 right_shift = 1;
+	bool mouse_input = 1;
+	int dir = 0;
+
+	/* newer iMON device PAD or mouse button */
+	if (ictx->product != 0xffdc && (buf[0] & 0x01) && len == 5) {
+		rel_x = buf[2];
+		rel_y = buf[3];
+		right_shift = 1;
+	/* 0xffdc iMON PAD or mouse button input */
+	} else if (ictx->product == 0xffdc && (buf[0] & 0x40) &&
+			!((buf[1] & 0x01) || ((buf[1] >> 2) & 0x01))) {
+		rel_x = (buf[1] & 0x08) | (buf[1] & 0x10) >> 2 |
+			(buf[1] & 0x20) >> 4 | (buf[1] & 0x40) >> 6;
+		if (buf[0] & 0x02)
+			rel_x |= ~0x0f;
+		rel_x = rel_x + rel_x / 2;
+		rel_y = (buf[2] & 0x08) | (buf[2] & 0x10) >> 2 |
+			(buf[2] & 0x20) >> 4 | (buf[2] & 0x40) >> 6;
+		if (buf[0] & 0x01)
+			rel_y |= ~0x0f;
+		rel_y = rel_y + rel_y / 2;
+		right_shift = 2;
+	/* some ffdc devices decode mouse buttons differently... */
+	} else if (ictx->product == 0xffdc && (buf[0] == 0x68)) {
+		right_shift = 2;
+	/* ch+/- buttons, which we use for an emulated scroll wheel */
+	} else if (ictx->kc == KEY_CHANNELUP && (buf[2] & 0x40) != 0x40) {
+		dir = 1;
+	} else if (ictx->kc == KEY_CHANNELDOWN && (buf[2] & 0x40) != 0x40) {
+		dir = -1;
+	} else
+		mouse_input = 0;
+
+	if (mouse_input) {
+		dev_dbg(ictx->dev, "sending mouse data via input subsystem\n");
+
+		if (dir) {
+			input_report_rel(ictx->idev, REL_WHEEL, dir);
+		} else if (rel_x || rel_y) {
+			input_report_rel(ictx->idev, REL_X, rel_x);
+			input_report_rel(ictx->idev, REL_Y, rel_y);
+		} else {
+			input_report_key(ictx->idev, BTN_LEFT, buf[1] & 0x1);
+			input_report_key(ictx->idev, BTN_RIGHT,
+					 buf[1] >> right_shift & 0x1);
+		}
+		input_sync(ictx->idev);
+		ictx->last_keycode = ictx->kc;
+	}
+
+	return mouse_input;
+}
+
+static void imon_touch_event(struct imon_context *ictx, unsigned char *buf)
+{
+	mod_timer(&ictx->ttimer, jiffies + TOUCH_TIMEOUT);
+	ictx->touch_x = (buf[0] << 4) | (buf[1] >> 4);
+	ictx->touch_y = 0xfff - ((buf[2] << 4) | (buf[1] & 0xf));
+	input_report_abs(ictx->touch, ABS_X, ictx->touch_x);
+	input_report_abs(ictx->touch, ABS_Y, ictx->touch_y);
+	input_report_key(ictx->touch, BTN_TOUCH, 0x01);
+	input_sync(ictx->touch);
+}
+
+static void imon_pad_to_keys(struct imon_context *ictx, unsigned char *buf)
+{
+	int dir = 0;
+	char rel_x = 0x00, rel_y = 0x00;
+	u16 timeout, threshold;
+	u64 temp_key;
+	u32 remote_key;
+
+	/*
+	 * The imon directional pad functions more like a touchpad. Bytes 3 & 4
+	 * contain a position coordinate (x,y), with each component ranging
+	 * from -14 to 14. We want to down-sample this to only 4 discrete values
+	 * for up/down/left/right arrow keys. Also, when you get too close to
+	 * diagonals, it has a tendancy to jump back and forth, so lets try to
+	 * ignore when they get too close.
+	 */
+	if (ictx->product != 0xffdc) {
+		/* first, pad to 8 bytes so it conforms with everything else */
+		buf[5] = buf[6] = buf[7] = 0;
+		timeout = 500;	/* in msecs */
+		/* (2*threshold) x (2*threshold) square */
+		threshold = pad_thresh ? pad_thresh : 28;
+		rel_x = buf[2];
+		rel_y = buf[3];
+
+		if (ictx->ir_protocol == IMON_IR_PROTOCOL_IMON) {
+			if ((buf[1] == 0) && ((rel_x != 0) || (rel_y != 0))) {
+				dir = stabilize((int)rel_x, (int)rel_y,
+						timeout, threshold);
+				if (!dir) {
+					ictx->kc = KEY_UNKNOWN;
+					return;
+				}
+				buf[2] = dir & 0xFF;
+				buf[3] = (dir >> 8) & 0xFF;
+				memcpy(&temp_key, buf, sizeof(temp_key));
+				remote_key = (u32) (le64_to_cpu(temp_key)
+						    & 0xffffffff);
+				ictx->kc = imon_remote_key_lookup(ictx,
+								  remote_key);
+			}
+		} else {
+			if (abs(rel_y) > abs(rel_x)) {
+				buf[2] = (rel_y > 0) ? 0x7F : 0x80;
+				buf[3] = 0;
+				ictx->kc = (rel_y > 0) ? KEY_DOWN : KEY_UP;
+			} else {
+				buf[2] = 0;
+				buf[3] = (rel_x > 0) ? 0x7F : 0x80;
+				ictx->kc = (rel_x > 0) ? KEY_RIGHT : KEY_LEFT;
+			}
+		}
+
+	/*
+	 * Handle on-board decoded pad events for e.g. older VFD/iMON-Pad
+	 * device (15c2:ffdc). The remote generates various codes from
+	 * 0x68nnnnB7 to 0x6AnnnnB7, the left mouse button generates
+	 * 0x688301b7 and the right one 0x688481b7. All other keys generate
+	 * 0x2nnnnnnn. Position coordinate is encoded in buf[1] and buf[2] with
+	 * reversed endianess. Extract direction from buffer, rotate endianess,
+	 * adjust sign and feed the values into stabilize(). The resulting codes
+	 * will be 0x01008000, 0x01007F00, which match the newer devices.
+	 */
+	} else {
+		timeout = 10;	/* in msecs */
+		/* (2*threshold) x (2*threshold) square */
+		threshold = pad_thresh ? pad_thresh : 15;
+
+		/* buf[1] is x */
+		rel_x = (buf[1] & 0x08) | (buf[1] & 0x10) >> 2 |
+			(buf[1] & 0x20) >> 4 | (buf[1] & 0x40) >> 6;
+		if (buf[0] & 0x02)
+			rel_x |= ~0x10+1;
+		/* buf[2] is y */
+		rel_y = (buf[2] & 0x08) | (buf[2] & 0x10) >> 2 |
+			(buf[2] & 0x20) >> 4 | (buf[2] & 0x40) >> 6;
+		if (buf[0] & 0x01)
+			rel_y |= ~0x10+1;
+
+		buf[0] = 0x01;
+		buf[1] = buf[4] = buf[5] = buf[6] = buf[7] = 0;
+
+		if (ictx->ir_protocol == IMON_IR_PROTOCOL_IMON) {
+			dir = stabilize((int)rel_x, (int)rel_y,
+					timeout, threshold);
+			if (!dir) {
+				ictx->kc = KEY_UNKNOWN;
+				return;
+			}
+			buf[2] = dir & 0xFF;
+			buf[3] = (dir >> 8) & 0xFF;
+			memcpy(&temp_key, buf, sizeof(temp_key));
+			remote_key = (u32) (le64_to_cpu(temp_key) & 0xffffffff);
+			ictx->kc = imon_remote_key_lookup(ictx, remote_key);
+		} else {
+			if (abs(rel_y) > abs(rel_x)) {
+				buf[2] = (rel_y > 0) ? 0x7F : 0x80;
+				buf[3] = 0;
+				ictx->kc = (rel_y > 0) ? KEY_DOWN : KEY_UP;
+			} else {
+				buf[2] = 0;
+				buf[3] = (rel_x > 0) ? 0x7F : 0x80;
+				ictx->kc = (rel_x > 0) ? KEY_RIGHT : KEY_LEFT;
+			}
+		}
+	}
+}
+
+static int imon_parse_press_type(struct imon_context *ictx,
+				 unsigned char *buf, u8 ktype)
+{
+	int press_type = 0;
+
+	/* key release of 0x02XXXXXX key */
+	if (ictx->kc == KEY_RESERVED && buf[0] == 0x02 && buf[3] == 0x00)
+		ictx->kc = ictx->last_keycode;
+
+	/* mouse button release on (some) 0xffdc devices */
+	else if (ictx->kc == KEY_RESERVED && buf[0] == 0x68 && buf[1] == 0x82 &&
+		 buf[2] == 0x81 && buf[3] == 0xb7)
+		ictx->kc = ictx->last_keycode;
+
+	/* mouse button release on (some other) 0xffdc devices */
+	else if (ictx->kc == KEY_RESERVED && buf[0] == 0x01 && buf[1] == 0x00 &&
+		 buf[2] == 0x81 && buf[3] == 0xb7)
+		ictx->kc = ictx->last_keycode;
+
+	/* mce-specific button handling */
+	else if (ktype == IMON_KEY_MCE) {
+		/* initial press */
+		if (ictx->kc != ictx->last_keycode
+		    || buf[2] != ictx->mce_toggle_bit) {
+			ictx->last_keycode = ictx->kc;
+			ictx->mce_toggle_bit = buf[2];
+			press_type = 1;
+			mod_timer(&ictx->itimer,
+				  jiffies + msecs_to_jiffies(MCE_TIMEOUT_MS));
+		/* repeat */
+		} else {
+			press_type = 2;
+			mod_timer(&ictx->itimer,
+				  jiffies + msecs_to_jiffies(MCE_TIMEOUT_MS));
+		}
+
+	/* incoherent or irrelevant data */
+	} else if (ictx->kc == KEY_RESERVED)
+		press_type = -EINVAL;
+
+	/* key release of 0xXXXXXXb7 key */
+	else if (ictx->release_code)
+		press_type = 0;
+
+	/* this is a button press */
+	else
+		press_type = 1;
+
+	return press_type;
+}
+
+/**
+ * Process the incoming packet
+ */
+static void imon_incoming_packet(struct imon_context *ictx,
+				 struct urb *urb, int intf)
+{
+	int len = urb->actual_length;
+	unsigned char *buf = urb->transfer_buffer;
+	struct device *dev = ictx->dev;
+	u32 kc;
+	bool norelease = 0;
+	int i;
+	u64 temp_key;
+	u64 panel_key = 0;
+	u32 remote_key = 0;
+	struct input_dev *idev = NULL;
+	int press_type = 0;
+	int msec;
+	struct timeval t;
+	static struct timeval prev_time = { 0, 0 };
+	u8 ktype = IMON_KEY_IMON;
+
+	idev = ictx->idev;
+
+	/* filter out junk data on the older 0xffdc imon devices */
+	if ((buf[0] == 0xff) && (buf[7] == 0xff))
+		return;
+
+	/* Figure out what key was pressed */
+	memcpy(&temp_key, buf, sizeof(temp_key));
+	if (len == 8 && buf[7] == 0xee) {
+		ktype = IMON_KEY_PANEL;
+		panel_key = le64_to_cpu(temp_key);
+		kc = imon_panel_key_lookup(panel_key);
+	} else {
+		remote_key = (u32) (le64_to_cpu(temp_key) & 0xffffffff);
+		if (ictx->ir_protocol == IMON_IR_PROTOCOL_MCE) {
+			if (buf[0] == 0x80)
+				ktype = IMON_KEY_MCE;
+			kc = imon_mce_key_lookup(ictx, remote_key);
+		} else
+			kc = imon_remote_key_lookup(ictx, remote_key);
+	}
+
+	/* keyboard/mouse mode toggle button */
+	if (kc == KEY_KEYBOARD && !ictx->release_code) {
+		ictx->last_keycode = kc;
+		if (!nomouse) {
+			ictx->pad_mouse = ~(ictx->pad_mouse) & 0x1;
+			dev_dbg(dev, "toggling to %s mode\n",
+				ictx->pad_mouse ? "mouse" : "keyboard");
+			return;
+		} else {
+			ictx->pad_mouse = 0;
+			dev_dbg(dev, "mouse mode disabled, passing key value\n");
+		}
+	}
+
+	ictx->kc = kc;
+
+	/* send touchscreen events through input subsystem if touchpad data */
+	if (ictx->display_type == IMON_DISPLAY_TYPE_VGA && len == 8 &&
+	    buf[7] == 0x86) {
+		imon_touch_event(ictx, buf);
+
+	/* look for mouse events with pad in mouse mode */
+	} else if (ictx->pad_mouse) {
+		if (imon_mouse_event(ictx, buf, len))
+			return;
+	}
+
+	/* Now for some special handling to convert pad input to arrow keys */
+	if (((len == 5) && (buf[0] == 0x01) && (buf[4] == 0x00)) ||
+	    ((len == 8) && (buf[0] & 0x40) &&
+	     !(buf[1] & 0x1 || buf[1] >> 2 & 0x1))) {
+		len = 8;
+		imon_pad_to_keys(ictx, buf);
+		norelease = 1;
+	}
+
+	if (debug) {
+		printk(KERN_INFO "intf%d decoded packet: ", intf);
+		for (i = 0; i < len; ++i)
+			printk("%02x ", buf[i]);
+		printk("\n");
+	}
+
+	press_type = imon_parse_press_type(ictx, buf, ktype);
+	if (press_type < 0)
+		goto not_input_data;
+
+	if (ictx->kc == KEY_UNKNOWN)
+		goto unknown_key;
+
+	/* KEY_MUTE repeats from MCE and knob need to be suppressed */
+	if ((ictx->kc == KEY_MUTE && ictx->kc == ictx->last_keycode)
+	    && (buf[7] == 0xee || ktype == IMON_KEY_MCE)) {
+		do_gettimeofday(&t);
+		msec = tv2int(&t, &prev_time);
+		prev_time = t;
+		if (msec < 200)
+			return;
+	}
+
+	input_report_key(idev, ictx->kc, press_type);
+	input_sync(idev);
+
+	/* panel keys and some remote keys don't generate a release */
+	if (panel_key || norelease) {
+		input_report_key(idev, ictx->kc, 0);
+		input_sync(idev);
+	}
+
+	ictx->last_keycode = ictx->kc;
+
+	return;
+
+unknown_key:
+	dev_info(dev, "%s: unknown keypress, code 0x%llx\n", __func__,
+		 (panel_key ? be64_to_cpu(panel_key) :
+			      be32_to_cpu(remote_key)));
+	return;
+
+not_input_data:
+	if (len != 8) {
+		dev_warn(dev, "imon %s: invalid incoming packet "
+			 "size (len = %d, intf%d)\n", __func__, len, intf);
+		return;
+	}
+
+	/* iMON 2.4G associate frame */
+	if (buf[0] == 0x00 &&
+	    buf[2] == 0xFF &&				/* REFID */
+	    buf[3] == 0xFF &&
+	    buf[4] == 0xFF &&
+	    buf[5] == 0xFF &&				/* iMON 2.4G */
+	   ((buf[6] == 0x4E && buf[7] == 0xDF) ||	/* LT */
+	    (buf[6] == 0x5E && buf[7] == 0xDF))) {	/* DT */
+		dev_warn(dev, "%s: remote associated refid=%02X\n",
+			 __func__, buf[1]);
+		ictx->rf_isassociating = 0;
+	}
+}
+
+/**
+ * Callback function for USB core API: receive data
+ */
+static void usb_rx_callback_intf0(struct urb *urb)
+{
+	struct imon_context *ictx;
+	int intfnum = 0;
+
+	if (!urb)
+		return;
+
+	ictx = (struct imon_context *)urb->context;
+	if (!ictx)
+		return;
+
+	switch (urb->status) {
+	case -ENOENT:		/* usbcore unlink successful! */
+		return;
+
+	case -ESHUTDOWN:	/* transport endpoint was shut down */
+		break;
+
+	case 0:
+		imon_incoming_packet(ictx, urb, intfnum);
+		break;
+
+	default:
+		dev_warn(ictx->dev, "imon %s: status(%d): ignored\n",
+			 __func__, urb->status);
+		break;
+	}
+
+	usb_submit_urb(ictx->rx_urb_intf0, GFP_ATOMIC);
+}
+
+static void usb_rx_callback_intf1(struct urb *urb)
+{
+	struct imon_context *ictx;
+	int intfnum = 1;
+
+	if (!urb)
+		return;
+
+	ictx = (struct imon_context *)urb->context;
+	if (!ictx)
+		return;
+
+	switch (urb->status) {
+	case -ENOENT:		/* usbcore unlink successful! */
+		return;
+
+	case -ESHUTDOWN:	/* transport endpoint was shut down */
+		break;
+
+	case 0:
+		imon_incoming_packet(ictx, urb, intfnum);
+		break;
+
+	default:
+		dev_warn(ictx->dev, "imon %s: status(%d): ignored\n",
+			 __func__, urb->status);
+		break;
+	}
+
+	usb_submit_urb(ictx->rx_urb_intf1, GFP_ATOMIC);
+}
+
+static struct input_dev *imon_init_idev(struct imon_context *ictx)
+{
+	struct input_dev *idev;
+	struct ir_dev_props *props;
+	struct ir_input_dev *ir;
+	int ret, i;
+	char *ir_codes = NULL;
+
+	if (ir_protocol == IMON_IR_PROTOCOL_MCE)
+		ir_codes = RC_MAP_IMON_MCE;
+	else
+		ir_codes = RC_MAP_IMON_PAD;
+
+	idev = input_allocate_device();
+	if (!idev) {
+		dev_err(ictx->dev, "remote input dev allocation failed\n");
+		goto idev_alloc_failed;
+	}
+
+	props = kzalloc(sizeof(struct ir_dev_props), GFP_KERNEL);
+	if (!props) {
+		dev_err(ictx->dev, "remote ir dev props allocation failed\n");
+		goto props_alloc_failed;
+	}
+
+	ir = kzalloc(sizeof(struct ir_input_dev), GFP_KERNEL);
+	if (!props) {
+		dev_err(ictx->dev, "remote ir input dev allocation failed\n");
+		goto ir_dev_alloc_failed;
+	}
+
+	snprintf(ictx->name_idev, sizeof(ictx->name_idev),
+		 "iMON Remote (%04x:%04x)", ictx->vendor, ictx->product);
+	idev->name = ictx->name_idev;
+
+	usb_make_path(ictx->usbdev_intf0, ictx->phys_idev,
+		      sizeof(ictx->phys_idev));
+	strlcat(ictx->phys_idev, "/input0", sizeof(ictx->phys_idev));
+	idev->phys = ictx->phys_idev;
+
+	idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL);
+
+	idev->keybit[BIT_WORD(BTN_MOUSE)] =
+		BIT_MASK(BTN_LEFT) | BIT_MASK(BTN_RIGHT);
+	idev->relbit[0] = BIT_MASK(REL_X) | BIT_MASK(REL_Y) |
+		BIT_MASK(REL_WHEEL);
+
+	/* panel and/or knob code support */
+	for (i = 0; i < ARRAY_SIZE(imon_panel_key_table); i++) {
+		u32 kc = imon_panel_key_table[i].keycode;
+		__set_bit(kc, idev->keybit);
+	}
+
+	props->driver_type = RC_DRIVER_SCANCODE;
+	props->allowed_protos = IR_TYPE_UNKNOWN;
+
+	ictx->ir = ir;
+	memcpy(&ir->dev, ictx->dev, sizeof(struct device));
+
+	usb_to_input_id(ictx->usbdev_intf0, &idev->id);
+	idev->dev.parent = ictx->dev;
+
+	input_set_drvdata(idev, ir);
+
+	ret = ir_input_register(idev, ir_codes, props, MOD_NAME);
+	if (ret < 0) {
+		dev_err(ictx->dev, "remote input dev register failed\n");
+		goto idev_register_failed;
+	}
+
+	return idev;
+
+idev_register_failed:
+	kfree(ir);
+ir_dev_alloc_failed:
+	kfree(props);
+props_alloc_failed:
+	input_free_device(idev);
+idev_alloc_failed:
+
+	return NULL;
+}
+
+static struct input_dev *imon_init_touch(struct imon_context *ictx)
+{
+	struct input_dev *touch;
+	int ret;
+
+	touch = input_allocate_device();
+	if (!touch) {
+		dev_err(ictx->dev, "touchscreen input dev allocation failed\n");
+		goto touch_alloc_failed;
+	}
+
+	snprintf(ictx->name_touch, sizeof(ictx->name_touch),
+		 "iMON USB Touchscreen (%04x:%04x)",
+		 ictx->vendor, ictx->product);
+	touch->name = ictx->name_touch;
+
+	usb_make_path(ictx->usbdev_intf1, ictx->phys_touch,
+		      sizeof(ictx->phys_touch));
+	strlcat(ictx->phys_touch, "/input1", sizeof(ictx->phys_touch));
+	touch->phys = ictx->phys_touch;
+
+	touch->evbit[0] =
+		BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+	touch->keybit[BIT_WORD(BTN_TOUCH)] =
+		BIT_MASK(BTN_TOUCH);
+	input_set_abs_params(touch, ABS_X,
+			     0x00, 0xfff, 0, 0);
+	input_set_abs_params(touch, ABS_Y,
+			     0x00, 0xfff, 0, 0);
+
+	input_set_drvdata(touch, ictx);
+
+	usb_to_input_id(ictx->usbdev_intf1, &touch->id);
+	touch->dev.parent = ictx->dev;
+	ret = input_register_device(touch);
+	if (ret <  0) {
+		dev_info(ictx->dev, "touchscreen input dev register failed\n");
+		goto touch_register_failed;
+	}
+
+	return touch;
+
+touch_register_failed:
+	input_free_device(ictx->touch);
+	mutex_unlock(&ictx->lock);
+
+touch_alloc_failed:
+	return NULL;
+}
+
+static bool imon_find_endpoints(struct imon_context *ictx,
+				struct usb_host_interface *iface_desc)
+{
+	struct usb_endpoint_descriptor *ep;
+	struct usb_endpoint_descriptor *rx_endpoint = NULL;
+	struct usb_endpoint_descriptor *tx_endpoint = NULL;
+	int ifnum = iface_desc->desc.bInterfaceNumber;
+	int num_endpts = iface_desc->desc.bNumEndpoints;
+	int i, ep_dir, ep_type;
+	bool ir_ep_found = 0;
+	bool display_ep_found = 0;
+	bool tx_control = 0;
+
+	/*
+	 * 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) {
+		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(ictx->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(ictx->dev, "%s: found display endpoint\n", __func__);
+		}
+	}
+
+	if (ifnum == 0) {
+		ictx->rx_endpoint_intf0 = rx_endpoint;
+		/*
+		 * tx is used to send characters to lcd/vfd, associate RF
+		 * remotes, set IR protocol, and maybe more...
+		 */
+		ictx->tx_endpoint = tx_endpoint;
+	} else {
+		ictx->rx_endpoint_intf1 = rx_endpoint;
+	}
+
+	/*
+	 * If we didn't find a display endpoint, this is probably one of the
+	 * newer iMON devices that use control urb instead of interrupt
+	 */
+	if (!display_ep_found) {
+		tx_control = 1;
+		display_ep_found = 1;
+		dev_dbg(ictx->dev, "%s: device uses control endpoint, not "
+			"interface OUT endpoint\n", __func__);
+	}
+
+	/*
+	 * Some iMON receivers have no display. Unfortunately, it seems
+	 * that SoundGraph recycles device IDs between devices both with
+	 * and without... :\
+	 */
+	if (ictx->display_type == IMON_DISPLAY_TYPE_NONE) {
+		display_ep_found = 0;
+		dev_dbg(ictx->dev, "%s: device has no display\n", __func__);
+	}
+
+	/*
+	 * iMON Touch devices have a VGA touchscreen, but no "display", as
+	 * that refers to e.g. /dev/lcd0 (a character device LCD or VFD).
+	 */
+	if (ictx->display_type == IMON_DISPLAY_TYPE_VGA) {
+		display_ep_found = 0;
+		dev_dbg(ictx->dev, "%s: iMON Touch device found\n", __func__);
+	}
+
+	/* Input endpoint is mandatory */
+	if (!ir_ep_found)
+		err("%s: no valid input (IR) endpoint found.", __func__);
+
+	ictx->tx_control = tx_control;
+
+	if (display_ep_found)
+		ictx->display_supported = true;
+
+	return ir_ep_found;
+
+}
+
+static struct imon_context *imon_init_intf0(struct usb_interface *intf)
+{
+	struct imon_context *ictx;
+	struct urb *rx_urb;
+	struct urb *tx_urb;
+	struct device *dev = &intf->dev;
+	struct usb_host_interface *iface_desc;
+	int ret;
+
+	ictx = kzalloc(sizeof(struct imon_context), GFP_KERNEL);
+	if (!ictx) {
+		dev_err(dev, "%s: kzalloc failed for context", __func__);
+		goto exit;
+	}
+	rx_urb = usb_alloc_urb(0, GFP_KERNEL);
+	if (!rx_urb) {
+		dev_err(dev, "%s: usb_alloc_urb failed for IR urb", __func__);
+		goto rx_urb_alloc_failed;
+	}
+	tx_urb = usb_alloc_urb(0, GFP_KERNEL);
+	if (!tx_urb) {
+		dev_err(dev, "%s: usb_alloc_urb failed for display urb",
+			__func__);
+		goto tx_urb_alloc_failed;
+	}
+
+	mutex_init(&ictx->lock);
+
+	mutex_lock(&ictx->lock);
+
+	ictx->dev = dev;
+	ictx->usbdev_intf0 = usb_get_dev(interface_to_usbdev(intf));
+	ictx->dev_present_intf0 = 1;
+	ictx->rx_urb_intf0 = rx_urb;
+	ictx->tx_urb = tx_urb;
+
+	ictx->vendor  = le16_to_cpu(ictx->usbdev_intf0->descriptor.idVendor);
+	ictx->product = le16_to_cpu(ictx->usbdev_intf0->descriptor.idProduct);
+
+	iface_desc = intf->cur_altsetting;
+	if (!imon_find_endpoints(ictx, iface_desc))
+		goto find_endpoint_failed;
+
+	ictx->idev = imon_init_idev(ictx);
+	if (!ictx->idev) {
+		dev_err(dev, "%s: input device setup failed\n", __func__);
+		goto idev_setup_failed;
+	}
+
+	usb_fill_int_urb(ictx->rx_urb_intf0, ictx->usbdev_intf0,
+		usb_rcvintpipe(ictx->usbdev_intf0,
+			ictx->rx_endpoint_intf0->bEndpointAddress),
+		ictx->usb_rx_buf, sizeof(ictx->usb_rx_buf),
+		usb_rx_callback_intf0, ictx,
+		ictx->rx_endpoint_intf0->bInterval);
+
+	ret = usb_submit_urb(ictx->rx_urb_intf0, GFP_KERNEL);
+	if (ret) {
+		err("%s: usb_submit_urb failed for intf0 (%d)",
+		    __func__, ret);
+		goto urb_submit_failed;
+	}
+
+	return ictx;
+
+urb_submit_failed:
+	input_unregister_device(ictx->idev);
+	input_free_device(ictx->idev);
+idev_setup_failed:
+find_endpoint_failed:
+	mutex_unlock(&ictx->lock);
+	usb_free_urb(tx_urb);
+tx_urb_alloc_failed:
+	usb_free_urb(rx_urb);
+rx_urb_alloc_failed:
+	kfree(ictx);
+exit:
+	dev_err(dev, "unable to initialize intf0, err %d\n", ret);
+
+	return NULL;
+}
+
+static struct imon_context *imon_init_intf1(struct usb_interface *intf,
+					    struct imon_context *ictx)
+{
+	struct urb *rx_urb;
+	struct usb_host_interface *iface_desc;
+	int ret;
+
+	rx_urb = usb_alloc_urb(0, GFP_KERNEL);
+	if (!rx_urb) {
+		err("%s: usb_alloc_urb failed for IR urb", __func__);
+		ret = -ENOMEM;
+		goto rx_urb_alloc_failed;
+	}
+
+	mutex_lock(&ictx->lock);
+
+	if (ictx->display_type == IMON_DISPLAY_TYPE_VGA) {
+		init_timer(&ictx->ttimer);
+		ictx->ttimer.data = (unsigned long)ictx;
+		ictx->ttimer.function = imon_touch_display_timeout;
+	}
+
+	ictx->usbdev_intf1 = usb_get_dev(interface_to_usbdev(intf));
+	ictx->dev_present_intf1 = 1;
+	ictx->rx_urb_intf1 = rx_urb;
+
+	iface_desc = intf->cur_altsetting;
+	if (!imon_find_endpoints(ictx, iface_desc))
+		goto find_endpoint_failed;
+
+	if (ictx->display_type == IMON_DISPLAY_TYPE_VGA) {
+		ictx->touch = imon_init_touch(ictx);
+		if (!ictx->touch)
+			goto touch_setup_failed;
+	} else
+		ictx->touch = NULL;
+
+	usb_fill_int_urb(ictx->rx_urb_intf1, ictx->usbdev_intf1,
+		usb_rcvintpipe(ictx->usbdev_intf1,
+			ictx->rx_endpoint_intf1->bEndpointAddress),
+		ictx->usb_rx_buf, sizeof(ictx->usb_rx_buf),
+		usb_rx_callback_intf1, ictx,
+		ictx->rx_endpoint_intf1->bInterval);
+
+	ret = usb_submit_urb(ictx->rx_urb_intf1, GFP_KERNEL);
+
+	if (ret) {
+		err("%s: usb_submit_urb failed for intf1 (%d)",
+		    __func__, ret);
+		goto urb_submit_failed;
+	}
+
+	return ictx;
+
+urb_submit_failed:
+	if (ictx->touch) {
+		input_unregister_device(ictx->touch);
+		input_free_device(ictx->touch);
+	}
+touch_setup_failed:
+find_endpoint_failed:
+	mutex_unlock(&ictx->lock);
+	usb_free_urb(rx_urb);
+rx_urb_alloc_failed:
+	dev_err(ictx->dev, "unable to initialize intf0, err %d\n", ret);
+
+	return NULL;
+}
+
+/*
+ * The 0x15c2:0xffdc device ID was used for umpteen different imon
+ * devices, and all of them constantly spew interrupts, even when there
+ * is no actual data to report. However, byte 6 of this buffer looks like
+ * its unique across device variants, so we're trying to key off that to
+ * figure out which display type (if any) and what IR protocol the device
+ * actually supports.
+ */
+static void imon_get_ffdc_type(struct imon_context *ictx)
+{
+	u8 ffdc_cfg_byte = ictx->usb_rx_buf[6];
+	u8 detected_display_type = IMON_DISPLAY_TYPE_NONE;
+	u8 ir_proto_mask = IMON_IR_PROTO_MASK_IMON;
+
+	switch (ffdc_cfg_byte) {
+	/* iMON Knob, no display, iMON IR + vol knob */
+	case 0x21:
+		dev_info(ictx->dev, "0xffdc iMON Knob, iMON IR");
+		ictx->display_supported = false;
+		break;
+	/* iMON VFD, no IR (does have vol knob tho) */
+	case 0x35:
+		dev_info(ictx->dev, "0xffdc iMON VFD + knob, no IR");
+		detected_display_type = IMON_DISPLAY_TYPE_VFD;
+		ir_proto_mask = IMON_IR_PROTO_MASK_NONE;
+		break;
+	/* iMON VFD, iMON IR */
+	case 0x24:
+	case 0x85:
+		dev_info(ictx->dev, "0xffdc iMON VFD, iMON IR");
+		detected_display_type = IMON_DISPLAY_TYPE_VFD;
+		break;
+	/* iMON LCD, MCE IR */
+	case 0x9f:
+		dev_info(ictx->dev, "0xffdc iMON LCD, MCE IR");
+		detected_display_type = IMON_DISPLAY_TYPE_LCD;
+		ir_proto_mask = IMON_IR_PROTO_MASK_MCE;
+		break;
+	default:
+		dev_info(ictx->dev, "Unknown 0xffdc device, "
+			 "defaulting to VFD and iMON IR");
+		detected_display_type = IMON_DISPLAY_TYPE_VFD;
+		break;
+	}
+
+	printk(" (id 0x%02x)\n", ffdc_cfg_byte);
+
+	ictx->display_type = detected_display_type;
+	ictx->ir_proto_mask = ir_proto_mask;
+}
+
+static void imon_set_display_type(struct imon_context *ictx,
+				  struct usb_interface *intf)
+{
+	u8 configured_display_type = IMON_DISPLAY_TYPE_VFD;
+
+	/*
+	 * 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 (display_type == IMON_DISPLAY_TYPE_AUTO) {
+		switch (ictx->product) {
+		case 0xffdc:
+			/* set in imon_get_ffdc_type() */
+			configured_display_type = ictx->display_type;
+			break;
+		case 0x0034:
+		case 0x0035:
+			configured_display_type = IMON_DISPLAY_TYPE_VGA;
+			break;
+		case 0x0038:
+		case 0x0039:
+		case 0x0045:
+			configured_display_type = IMON_DISPLAY_TYPE_LCD;
+			break;
+		case 0x003c:
+		case 0x0041:
+		case 0x0042:
+		case 0x0043:
+			configured_display_type = IMON_DISPLAY_TYPE_NONE;
+			ictx->display_supported = false;
+			break;
+		case 0x0036:
+		case 0x0044:
+		default:
+			configured_display_type = IMON_DISPLAY_TYPE_VFD;
+			break;
+		}
+	} else {
+		configured_display_type = display_type;
+		if (display_type == IMON_DISPLAY_TYPE_NONE)
+			ictx->display_supported = false;
+		else
+			ictx->display_supported = true;
+		dev_info(ictx->dev, "%s: overriding display type to %d via "
+			 "modparam\n", __func__, display_type);
+	}
+
+	ictx->display_type = configured_display_type;
+}
+
+static void imon_init_display(struct imon_context *ictx,
+			      struct usb_interface *intf)
+{
+	int ret;
+
+	dev_dbg(ictx->dev, "Registering iMON display with sysfs\n");
+
+	/* set up sysfs entry for built-in clock */
+	ret = sysfs_create_group(&intf->dev.kobj,
+				 &imon_display_attribute_group);
+	if (ret)
+		dev_err(ictx->dev, "Could not create display sysfs "
+			"entries(%d)", ret);
+
+	if (ictx->display_type == IMON_DISPLAY_TYPE_LCD)
+		ret = usb_register_dev(intf, &imon_lcd_class);
+	else
+		ret = usb_register_dev(intf, &imon_vfd_class);
+	if (ret)
+		/* Not a fatal error, so ignore */
+		dev_info(ictx->dev, "could not get a minor number for "
+			 "display\n");
+
+}
+
+/**
+ * Callback function for USB core API: Probe
+ */
+static int __devinit 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_interface *first_if;
+	struct device *dev = &interface->dev;
+	int ifnum, code_length, sysfs_err;
+	int ret = 0;
+	struct imon_context *ictx = NULL;
+	struct imon_context *first_if_ctx = NULL;
+	u16 vendor, product;
+	const unsigned char fp_packet[] = { 0x40, 0x00, 0x00, 0x00,
+					    0x00, 0x00, 0x00, 0x88 };
+
+	code_length = BUF_CHUNK_SIZE * 8;
+
+	usbdev     = usb_get_dev(interface_to_usbdev(interface));
+	iface_desc = interface->cur_altsetting;
+	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);
+
+	first_if = usb_ifnum_to_if(usbdev, 0);
+	first_if_ctx = (struct imon_context *)usb_get_intfdata(first_if);
+
+	if (ifnum == 0) {
+		ictx = imon_init_intf0(interface);
+		if (!ictx) {
+			err("%s: failed to initialize context!\n", __func__);
+			ret = -ENODEV;
+			goto fail;
+		}
+
+		if (product == 0xffdc) {
+			/* RF products *also* use 0xffdc... sigh... */
+			sysfs_err = sysfs_create_group(&interface->dev.kobj,
+						       &imon_rf_attribute_group);
+			if (sysfs_err)
+				err("%s: Could not create RF sysfs entries(%d)",
+				    __func__, sysfs_err);
+		}
+
+	} else {
+	/* this is the secondary interface on the device */
+		ictx = imon_init_intf1(interface, first_if_ctx);
+		if (!ictx) {
+			err("%s: failed to attach to context!\n", __func__);
+			ret = -ENODEV;
+			goto fail;
+		}
+
+	}
+
+	usb_set_intfdata(interface, ictx);
+
+	if (ifnum == 0) {
+		/* Enable front-panel buttons and/or knobs */
+		memcpy(ictx->usb_tx_buf, &fp_packet, sizeof(fp_packet));
+		ret = send_packet(ictx);
+		/* Not fatal, but warn about it */
+		if (ret)
+			dev_info(dev, "failed to enable panel buttons "
+				 "and/or knobs\n");
+
+		if (product == 0xffdc)
+			imon_get_ffdc_type(ictx);
+		else
+			ictx->ir_proto_mask = IMON_IR_PROTO_MASK_MCE |
+					      IMON_IR_PROTO_MASK_IMON;
+
+		imon_set_display_type(ictx, interface);
+
+		if (ictx->display_supported)
+			imon_init_display(ictx, interface);
+	}
+
+	/* set IR protocol/remote type */
+	imon_set_ir_protocol(ictx);
+
+	dev_info(dev, "iMON device (%04x:%04x, intf%d) on "
+		 "usb<%d:%d> initialized\n", vendor, product, ifnum,
+		 usbdev->bus->busnum, usbdev->devnum);
+
+	mutex_unlock(&ictx->lock);
+	mutex_unlock(&driver_lock);
+
+	return 0;
+
+fail:
+	mutex_unlock(&driver_lock);
+	dev_err(dev, "unable to register, err %d\n", ret);
+
+	return ret;
+}
+
+/**
+ * Callback function for USB core API: disconnect
+ */
+static void __devexit imon_disconnect(struct usb_interface *interface)
+{
+	struct imon_context *ictx;
+	struct device *dev;
+	int ifnum;
+
+	/* prevent races with multi-interface device probing and display_open */
+	mutex_lock(&driver_lock);
+
+	ictx = usb_get_intfdata(interface);
+	dev = ictx->dev;
+	ifnum = interface->cur_altsetting->desc.bInterfaceNumber;
+
+	mutex_lock(&ictx->lock);
+
+	/*
+	 * sysfs_remove_group is safe to call even if sysfs_create_group
+	 * hasn't been called
+	 */
+	sysfs_remove_group(&interface->dev.kobj,
+			   &imon_display_attribute_group);
+	sysfs_remove_group(&interface->dev.kobj,
+			   &imon_rf_attribute_group);
+
+	usb_set_intfdata(interface, NULL);
+
+	/* Abort ongoing write */
+	if (ictx->tx.busy) {
+		usb_kill_urb(ictx->tx_urb);
+		complete_all(&ictx->tx.finished);
+	}
+
+	if (ifnum == 0) {
+		ictx->dev_present_intf0 = 0;
+		usb_kill_urb(ictx->rx_urb_intf0);
+		input_unregister_device(ictx->idev);
+		if (ictx->display_supported) {
+			if (ictx->display_type == IMON_DISPLAY_TYPE_LCD)
+				usb_deregister_dev(interface, &imon_lcd_class);
+			else
+				usb_deregister_dev(interface, &imon_vfd_class);
+		}
+	} else {
+		ictx->dev_present_intf1 = 0;
+		usb_kill_urb(ictx->rx_urb_intf1);
+		if (ictx->display_type == IMON_DISPLAY_TYPE_VGA)
+			input_unregister_device(ictx->touch);
+	}
+
+	if (!ictx->dev_present_intf0 && !ictx->dev_present_intf1) {
+		if (ictx->display_type == IMON_DISPLAY_TYPE_VGA)
+			del_timer_sync(&ictx->ttimer);
+		mutex_unlock(&ictx->lock);
+		if (!ictx->display_isopen)
+			free_imon_context(ictx);
+	} else {
+		if (ictx->ir_protocol == IMON_IR_PROTOCOL_MCE)
+			del_timer_sync(&ictx->itimer);
+		mutex_unlock(&ictx->lock);
+	}
+
+	mutex_unlock(&driver_lock);
+
+	dev_dbg(dev, "%s: iMON device (intf%d) disconnected\n",
+		__func__, ifnum);
+}
+
+static int imon_suspend(struct usb_interface *intf, pm_message_t message)
+{
+	struct imon_context *ictx = usb_get_intfdata(intf);
+	int ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
+
+	if (ifnum == 0)
+		usb_kill_urb(ictx->rx_urb_intf0);
+	else
+		usb_kill_urb(ictx->rx_urb_intf1);
+
+	return 0;
+}
+
+static int imon_resume(struct usb_interface *intf)
+{
+	int rc = 0;
+	struct imon_context *ictx = usb_get_intfdata(intf);
+	int ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
+
+	if (ifnum == 0) {
+		usb_fill_int_urb(ictx->rx_urb_intf0, ictx->usbdev_intf0,
+			usb_rcvintpipe(ictx->usbdev_intf0,
+				ictx->rx_endpoint_intf0->bEndpointAddress),
+			ictx->usb_rx_buf, sizeof(ictx->usb_rx_buf),
+			usb_rx_callback_intf0, ictx,
+			ictx->rx_endpoint_intf0->bInterval);
+
+		rc = usb_submit_urb(ictx->rx_urb_intf0, GFP_ATOMIC);
+
+	} else {
+		usb_fill_int_urb(ictx->rx_urb_intf1, ictx->usbdev_intf1,
+			usb_rcvintpipe(ictx->usbdev_intf1,
+				ictx->rx_endpoint_intf1->bEndpointAddress),
+			ictx->usb_rx_buf, sizeof(ictx->usb_rx_buf),
+			usb_rx_callback_intf1, ictx,
+			ictx->rx_endpoint_intf1->bInterval);
+
+		rc = usb_submit_urb(ictx->rx_urb_intf1, GFP_ATOMIC);
+	}
+
+	return rc;
+}
+
+static int __init imon_init(void)
+{
+	int rc;
+
+	rc = usb_register(&imon_driver);
+	if (rc) {
+		err("%s: usb register failed(%d)", __func__, rc);
+		rc = -ENODEV;
+	}
+
+	return rc;
+}
+
+static void __exit imon_exit(void)
+{
+	usb_deregister(&imon_driver);
+}
+
+module_init(imon_init);
+module_exit(imon_exit);