Staging: add mimio xi driver

This patch adds the Mimio Xi interactive whiteboard driver to the tree.

It was originally written by [e-mail], but cleaned up and
forward ported by me to the latest kernel version.


Cc: Phil Hannent <[e-mail]>
Cc: <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/Kconfig

···
 
 source "drivers/staging/rspiusb/Kconfig"
 
+source "drivers/staging/mimio/Kconfig"
+
 endif # !STAGING_EXCLUDE_BUILD
 endif # STAGING

drivers/staging/Makefile

···
 obj-$(CONFIG_ALTERA_PCIE_CHDMA)	+= altpciechdma/
 obj-$(CONFIG_RTL8187SE)		+= rtl8187se/
 obj-$(CONFIG_USB_RSPI)		+= rspiusb/
+obj-$(CONFIG_INPUT_MIMIO)	+= mimio/

drivers/staging/mimio/Kconfig

···
+config INPUT_MIMIO
+	tristate "Mimio Xi interactive whiteboard support"
+	depends on USB
+	default N
+	help
+	  Say Y here if you want to use a Mimio Xi interactive
+	  whiteboard device.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called mimio.

drivers/staging/mimio/Makefile

···
+obj-$(CONFIG_INPUT_MIMIO)	+= mimio.o

drivers/staging/mimio/mimio.c

···
+/*
+ * Hardware event => input event mapping:
+ *
+ *
+ *
+ input.h:#define BTN_TOOL_PEN            0x140 black
+ input.h:#define BTN_TOOL_RUBBER         0x141 blue
+ input.h:#define BTN_TOOL_BRUSH          0x142 green
+ input.h:#define BTN_TOOL_PENCIL         0x143 red
+ input.h:#define BTN_TOOL_AIRBRUSH       0x144 eraser
+ input.h:#define BTN_TOOL_FINGER         0x145 small eraser
+ input.h:#define BTN_TOOL_MOUSE          0x146 mimio interactive
+ input.h:#define BTN_TOOL_LENS           0x147 mimio interactive but1
+ input.h:#define LOCALBTN_TOOL_EXTRA1    0x14a mimio interactive but2 == BTN_TOUCH
+ input.h:#define LOCALBTN_TOOL_EXTRA2    0x14b mimio extra pens (orange, brown, yellow, purple) == BTN_STYLUS
+ input.h:#define LOCALBTN_TOOL_EXTRA3    0x14c unused == BTN_STYLUS2
+ input.h:#define BTN_TOOL_DOUBLETAP      0x14d unused
+ input.h:#define BTN_TOOL_TRIPLETAP      0x14e unused
+ *
+ * MIMIO_EV_PENDOWN(MIMIO_PEN_K)     => EV_KEY BIT(BTN_TOOL_PEN)
+ * MIMIO_EV_PENDOWN(MIMIO_PEN_B)     => EV_KEY BIT(BTN_TOOL_RUBBER)
+ * MIMIO_EV_PENDOWN(MIMIO_PEN_G)     => EV_KEY BIT(BTN_TOOL_BRUSH)
+ * MIMIO_EV_PENDOWN(MIMIO_PEN_R)     => EV_KEY BIT(BTN_TOOL_PENCIL)
+ * MIMIO_EV_PENDOWN(MIMIO_PEN_E)     => EV_KEY BIT(BTN_TOOL_AIRBRUSH)
+ * MIMIO_EV_PENDOWN(MIMIO_PEN_ES)    => EV_KEY BIT(BTN_TOOL_FINGER)
+ * MIMIO_EV_PENDOWN(MIMIO_PEN_I)     => EV_KEY BIT(BTN_TOOL_MOUSE)
+ * MIMIO_EV_PENDOWN(MIMIO_PEN_IL)    => EV_KEY BIT(BTN_TOOL_LENS)
+ * MIMIO_EV_PENDOWN(MIMIO_PEN_IR)    => EV_KEY BIT(BTN_TOOL_DOUBLETAP)
+ * MIMIO_EV_PENDOWN(MIMIO_PEN_EX)    => EV_KEY BIT(BTN_TOOL_TRIPLETAP)
+ * MIMIO_EV_PENDATA                 => EV_ABS BIT(ABS_X), BIT(ABS_Y)
+ * MIMIO_EV_MEMRESET              => EV_KEY BIT(BTN_0)
+ * MIMIO_EV_ACC(ACC_NEWPAGE)       => EV_KEY BIT(BTN_1)
+ * MIMIO_EV_ACC(ACC_TAGPAGE)      => EV_KEY BIT(BTN_2)
+ * MIMIO_EV_ACC(ACC_PRINTPAGE)      => EV_KEY BIT(BTN_3)
+ * MIMIO_EV_ACC(ACC_MAXIMIZE)      => EV_KEY BIT(BTN_4)
+ * MIMIO_EV_ACC(ACC_FINDCTLPNL)      => EV_KEY BIT(BTN_5)
+ *
+ *
+ * open issues:
+ *      - cold-load of data captured when mimio in standalone mode not yet
+ *         supported; need to snoop Win32 box to see datastream for this.
+ *       - mimio mouse not yet supported; need to snoop Win32 box to see the
+ *         datastream for this.
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/input.h>
+#include <linux/usb.h>
+
+#define DRIVER_VERSION		"v0.031"
+#define DRIVER_AUTHOR		"[e-mail]"
+#define DRIVER_DESC		"USB mimio-xi driver"
+
+enum {UPVALUE, DOWNVALUE, MOVEVALUE};
+
+#define MIMIO_XRANGE_MAX	9600
+#define MIMIO_YRANGE_MAX	4800
+
+#define LOCALBTN_TOOL_EXTRA1	BTN_TOUCH
+#define LOCALBTN_TOOL_EXTRA2	BTN_STYLUS
+#define LOCALBTN_TOOL_EXTRA3	BTN_STYLUS2
+
+#define MIMIO_VENDOR_ID		0x08d3
+#define MIMIO_PRODUCT_ID	0x0001
+#define MIMIO_MAXPAYLOAD	(8)
+#define MIMIO_MAXNAMELEN	(64)
+#define MIMIO_TXWAIT		(1)
+#define MIMIO_TXDONE		(2)
+
+#define MIMIO_EV_PENDOWN	(0x22)
+#define MIMIO_EV_PENDATA	(0x24)
+#define MIMIO_EV_PENUP		(0x51)
+#define MIMIO_EV_MEMRESET	(0x45)
+#define MIMIO_EV_ACC		(0xb2)
+
+#define MIMIO_PEN_K		(1)	/* black pen */
+#define MIMIO_PEN_B		(2)	/* blue pen */
+#define MIMIO_PEN_G		(3)	/* green pen */
+#define MIMIO_PEN_R		(4)	/* red pen */
+/* 5, 6, 7, 8 are extra pens */
+#define MIMIO_PEN_E		(9)	/* big eraser */
+#define MIMIO_PEN_ES		(10)	/* lil eraser */
+#define MIMIO_PENJUMP_START	(10)
+#define MIMIO_PENJUMP		(6)
+#define MIMIO_PEN_I		(17)	/* mimio interactive */
+#define MIMIO_PEN_IL		(18)	/* mimio interactive button 1 */
+#define MIMIO_PEN_IR		(19)	/* mimio interactive button 2 */
+
+#define MIMIO_PEN_MAX		(MIMIO_PEN_IR)
+
+#define ACC_DONE		(0)
+#define ACC_NEWPAGE		(1)
+#define ACC_TAGPAGE		(2)
+#define ACC_PRINTPAGE		(4)
+#define ACC_MAXIMIZE		(8)
+#define ACC_FINDCTLPNL		(16)
+
+#define isvalidtxsize(n)	((n) > 0 && (n) <= MIMIO_MAXPAYLOAD)
+
+
+struct pktbuf {
+	unsigned char instr;
+	unsigned char buf[16];
+	unsigned char *p;
+	unsigned char *q;
+};
+
+struct usbintendpt {
+	dma_addr_t dma;
+	struct urb *urb;
+	unsigned char *buf;
+	struct usb_endpoint_descriptor *desc;
+};
+
+struct mimio {
+	struct input_dev *idev;
+	struct usb_device *udev;
+	struct usb_interface *uifc;
+	int open;
+	int present;
+	int greeted;
+	int txflags;
+	char phys[MIMIO_MAXNAMELEN];
+	struct usbintendpt in;
+	struct usbintendpt out;
+	struct pktbuf pktbuf;
+	unsigned char minor;
+	wait_queue_head_t waitq;
+	spinlock_t txlock;
+	void (*rxhandler)(struct mimio *, unsigned char *, unsigned int);
+	int last_pen_down;
+};
+
+static void mimio_close(struct input_dev *);
+static void mimio_dealloc(struct mimio *);
+static void mimio_disconnect(struct usb_interface *);
+static int mimio_greet(struct mimio *);
+static void mimio_irq_in(struct urb *);
+static void mimio_irq_out(struct urb *);
+static int mimio_open(struct input_dev *);
+static int mimio_probe(struct usb_interface *, const struct usb_device_id *);
+static void mimio_rx_handler(struct mimio *, unsigned char *, unsigned int);
+static int mimio_tx(struct mimio *, const char *, int);
+
+static char mimio_name[] = "VirtualInk mimio-Xi";
+static struct usb_device_id mimio_table [] = {
+	{ USB_DEVICE(MIMIO_VENDOR_ID, MIMIO_PRODUCT_ID) },
+	{ USB_DEVICE(0x0525, 0xa4a0) }, /* gadget zero firmware */
+	{ }
+};
+
+MODULE_DEVICE_TABLE(usb, mimio_table);
+
+static struct usb_driver mimio_driver = {
+	.name = "mimio",
+	.probe = mimio_probe,
+	.disconnect = mimio_disconnect,
+	.id_table = mimio_table,
+};
+
+static DECLARE_MUTEX(disconnect_sem);
+
+static void mimio_close(struct input_dev *idev)
+{
+	struct mimio *mimio;
+
+	mimio = input_get_drvdata(idev);
+	if (!mimio) {
+		dev_err(&idev->dev, "null mimio attached to input device\n");
+		return;
+	}
+
+	if (mimio->open <= 0)
+		dev_err(&idev->dev, "mimio not open.\n");
+	else
+		mimio->open--;
+
+	if (mimio->present == 0 && mimio->open == 0)
+		mimio_dealloc(mimio);
+}
+
+static void mimio_dealloc(struct mimio *mimio)
+{
+	if (mimio == NULL)
+		return;
+
+	usb_kill_urb(mimio->in.urb);
+
+	usb_kill_urb(mimio->out.urb);
+
+	if (mimio->idev) {
+		input_unregister_device(mimio->idev);
+		if (mimio->idev->grab)
+			input_close_device(mimio->idev->grab);
+		else
+			dev_dbg(&mimio->idev->dev, "mimio->idev->grab == NULL"
+				" -- didn't call input_close_device\n");
+	}
+
+	usb_free_urb(mimio->in.urb);
+
+	usb_free_urb(mimio->out.urb);
+
+	if (mimio->in.buf) {
+		usb_buffer_free(mimio->udev, MIMIO_MAXPAYLOAD, mimio->in.buf,
+				mimio->in.dma);
+	}
+
+	if (mimio->out.buf)
+		usb_buffer_free(mimio->udev, MIMIO_MAXPAYLOAD, mimio->out.buf,
+				mimio->out.dma);
+
+	if (mimio->idev)
+		input_free_device(mimio->idev);
+
+	kfree(mimio);
+}
+
+static void mimio_disconnect(struct usb_interface *ifc)
+{
+	struct mimio *mimio;
+
+	down(&disconnect_sem);
+
+	mimio = usb_get_intfdata(ifc);
+	usb_set_intfdata(ifc, NULL);
+	dev_dbg(&mimio->idev->dev, "disconnect\n");
+
+	if (mimio) {
+		mimio->present = 0;
+
+		if (mimio->open <= 0)
+			mimio_dealloc(mimio);
+	}
+
+	up(&disconnect_sem);
+}
+
+static int mimio_greet(struct mimio *mimio)
+{
+	const struct grtpkt {
+		int nbytes;
+		unsigned delay;
+		char data[8];
+	} grtpkts[] = {
+		{ 3, 0, { 0x11, 0x55, 0x44, 0x00, 0x00, 0x00, 0x00, 0x00 } },
+		{ 5, 0, { 0x53, 0x55, 0x00, 0x00, 0x06, 0x00, 0x00, 0x00 } },
+		{ 5, 0, { 0x43, 0x55, 0x00, 0x00, 0x16, 0x00, 0x00, 0x00 } },
+		{ 5, 0, { 0x33, 0x55, 0x00, 0x00, 0x66, 0x00, 0x00, 0x00 } },
+		{ 5, 0, { 0x13, 0x00, 0x5e, 0x02, 0x4f, 0x00, 0x00, 0x00 } },
+		{ 5, 0, { 0x13, 0x00, 0x04, 0x03, 0x14, 0x00, 0x00, 0x00 } },
+		{ 5, 2, { 0x13, 0x00, 0x00, 0x04, 0x17, 0x00, 0x00, 0x00 } },
+		{ 5, 0, { 0x13, 0x00, 0x0d, 0x08, 0x16, 0x00, 0x00, 0x00 } },
+		{ 5, 0, { 0x13, 0x00, 0x4d, 0x01, 0x5f, 0x00, 0x00, 0x00 } },
+		{ 3, 0, { 0xf1, 0x55, 0xa4, 0x00, 0x00, 0x00, 0x00, 0x00 } },
+		{ 7, 2, { 0x52, 0x55, 0x00, 0x07, 0x31, 0x55, 0x64, 0x00 } },
+		{ 0, 0, { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 } },
+	};
+	int rslt;
+	const struct grtpkt *pkt;
+
+	for (pkt = grtpkts; pkt->nbytes; pkt++) {
+		rslt = mimio_tx(mimio, pkt->data, pkt->nbytes);
+		if (rslt)
+			return rslt;
+		if (pkt->delay)
+			msleep(pkt->delay);
+	}
+
+	return 0;
+}
+
+static void mimio_irq_in(struct urb *urb)
+{
+	int rslt;
+	char *data;
+	const char *reason = "going down";
+	struct mimio *mimio;
+
+	mimio = urb->context;
+
+	if (mimio == NULL)
+		/* paranoia */
+		return;
+
+	switch (urb->status) {
+	case 0:
+		/* success */
+		break;
+	case -ETIMEDOUT:
+		reason = "timeout -- unplugged?";
+	case -ECONNRESET:
+	case -ENOENT:
+	case -ESHUTDOWN:
+		dev_dbg(&mimio->idev->dev, "%s.\n", reason);
+		return;
+	default:
+		dev_dbg(&mimio->idev->dev, "unknown urb-status: %d.\n",
+			urb->status);
+		goto exit;
+	}
+	data = mimio->in.buf;
+
+	if (mimio->rxhandler)
+		mimio->rxhandler(mimio, data, urb->actual_length);
+exit:
+	/*
+	 * Keep listening to device on same urb.
+	 */
+	rslt = usb_submit_urb(urb, GFP_ATOMIC);
+	if (rslt)
+		dev_err(&mimio->idev->dev, "usb_submit_urb failure: %d.\n",
+			rslt);
+}
+
+static void mimio_irq_out(struct urb *urb)
+{
+	unsigned long flags;
+	struct mimio *mimio;
+
+	mimio = urb->context;
+
+	if (urb->status)
+		dev_dbg(&mimio->idev->dev, "urb-status: %d.\n", urb->status);
+
+	spin_lock_irqsave(&mimio->txlock, flags);
+	mimio->txflags |= MIMIO_TXDONE;
+	spin_unlock_irqrestore(&mimio->txlock, flags);
+	wmb();
+	wake_up(&mimio->waitq);
+}
+
+static int mimio_open(struct input_dev *idev)
+{
+	int rslt;
+	struct mimio *mimio;
+
+	rslt = 0;
+	down(&disconnect_sem);
+	mimio = input_get_drvdata(idev);
+	dev_dbg(&idev->dev, "mimio_open\n");
+
+	if (mimio == NULL) {
+		dev_err(&idev->dev, "null mimio.\n");
+		rslt = -ENODEV;
+		goto exit;
+	}
+
+	if (mimio->open++)
+		goto exit;
+
+	if (mimio->present && !mimio->greeted) {
+		struct urb *urb = mimio->in.urb;
+		mimio->in.urb->dev = mimio->udev;
+		rslt = usb_submit_urb(mimio->in.urb, GFP_KERNEL);
+		if (rslt) {
+			dev_err(&idev->dev, "usb_submit_urb failure "
+				"(res = %d: %s). Not greeting.\n",
+				rslt,
+				(!urb ? "urb is NULL" :
+				 (urb->hcpriv ? "urb->hcpriv is non-NULL" :
+				  (!urb->complete ? "urb is not complete" :
+				   (urb->number_of_packets <= 0 ? "urb has no packets" :
+				    (urb->interval <= 0 ? "urb interval too small" :
+				     "urb interval too large or some other error"))))));
+			rslt = -EIO;
+			goto exit;
+		}
+		rslt = mimio_greet(mimio);
+		if (rslt == 0) {
+			dev_dbg(&idev->dev, "Mimio greeted OK.\n");
+			mimio->greeted = 1;
+		} else {
+			dev_dbg(&idev->dev, "Mimio greet Failure (%d)\n",
+				rslt);
+		}
+	}
+
+exit:
+	up(&disconnect_sem);
+	return rslt;
+}
+
+static int mimio_probe(struct usb_interface *ifc,
+		       const struct usb_device_id *id)
+{
+	char path[64];
+	int pipe, maxp;
+	struct mimio *mimio;
+	struct usb_device *udev;
+	struct usb_host_interface *hostifc;
+	struct input_dev *input_dev;
+	int res = 0;
+	int i;
+
+	udev = interface_to_usbdev(ifc);
+
+	mimio = kzalloc(sizeof(struct mimio), GFP_KERNEL);
+	if (!mimio)
+		return -ENOMEM;
+
+	input_dev = input_allocate_device();
+	if (!input_dev) {
+		mimio_dealloc(mimio);
+		return -ENOMEM;
+	}
+
+	mimio->uifc = ifc;
+	mimio->udev = udev;
+	mimio->pktbuf.p = mimio->pktbuf.buf;
+	mimio->pktbuf.q = mimio->pktbuf.buf;
+	/* init_input_dev(mimio->idev); */
+	mimio->idev = input_dev;
+	init_waitqueue_head(&mimio->waitq);
+	spin_lock_init(&mimio->txlock);
+	hostifc = ifc->cur_altsetting;
+
+	if (hostifc->desc.bNumEndpoints != 2) {
+		dev_err(&udev->dev, "Unexpected endpoint count: %d.\n",
+			hostifc->desc.bNumEndpoints);
+		mimio_dealloc(mimio);
+		return -ENODEV;
+	}
+
+	mimio->in.desc = &(hostifc->endpoint[0].desc);
+	mimio->out.desc = &(hostifc->endpoint[1].desc);
+
+	mimio->in.buf = usb_buffer_alloc(udev, MIMIO_MAXPAYLOAD, GFP_KERNEL,
+					 &mimio->in.dma);
+	mimio->out.buf = usb_buffer_alloc(udev, MIMIO_MAXPAYLOAD, GFP_KERNEL,
+					  &mimio->out.dma);
+
+	if (mimio->in.buf == NULL || mimio->out.buf == NULL) {
+		dev_err(&udev->dev, "usb_buffer_alloc failure.\n");
+		mimio_dealloc(mimio);
+		return -ENOMEM;
+	}
+
+	mimio->in.urb = usb_alloc_urb(0, GFP_KERNEL);
+	mimio->out.urb = usb_alloc_urb(0, GFP_KERNEL);
+
+	if (mimio->in.urb == NULL || mimio->out.urb == NULL) {
+		dev_err(&udev->dev, "usb_alloc_urb failure.\n");
+		mimio_dealloc(mimio);
+		return -ENOMEM;
+	}
+
+	/*
+	 * Build the input urb.
+	 */
+	pipe = usb_rcvintpipe(udev, mimio->in.desc->bEndpointAddress);
+	maxp = usb_maxpacket(udev, pipe, usb_pipeout(pipe));
+	if (maxp > MIMIO_MAXPAYLOAD)
+		maxp = MIMIO_MAXPAYLOAD;
+	usb_fill_int_urb(mimio->in.urb, udev, pipe, mimio->in.buf, maxp,
+			 mimio_irq_in, mimio, mimio->in.desc->bInterval);
+	mimio->in.urb->transfer_dma = mimio->in.dma;
+	mimio->in.urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+
+	/*
+	 * Build the output urb.
+	 */
+	pipe = usb_sndintpipe(udev, mimio->out.desc->bEndpointAddress);
+	maxp = usb_maxpacket(udev, pipe, usb_pipeout(pipe));
+	if (maxp > MIMIO_MAXPAYLOAD)
+		maxp = MIMIO_MAXPAYLOAD;
+	usb_fill_int_urb(mimio->out.urb, udev, pipe, mimio->out.buf, maxp,
+			 mimio_irq_out, mimio, mimio->out.desc->bInterval);
+	mimio->out.urb->transfer_dma = mimio->out.dma;
+	mimio->out.urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+
+	/*
+	 * Build input device info
+	 */
+	usb_make_path(udev, path, 64);
+	snprintf(mimio->phys, MIMIO_MAXNAMELEN, "%s/input0", path);
+	input_set_drvdata(input_dev, mimio);
+	/* input_dev->dev = &ifc->dev; */
+	input_dev->open = mimio_open;
+	input_dev->close = mimio_close;
+	input_dev->name = mimio_name;
+	input_dev->phys = mimio->phys;
+	input_dev->dev.parent = &ifc->dev;
+
+	input_dev->id.bustype = BUS_USB;
+	input_dev->id.vendor = le16_to_cpu(udev->descriptor.idVendor);
+	input_dev->id.product = le16_to_cpu(udev->descriptor.idProduct);
+	input_dev->id.version = le16_to_cpu(udev->descriptor.bcdDevice);
+
+	input_dev->evbit[0] |= BIT(EV_KEY) | BIT(EV_ABS);
+	for (i = BTN_TOOL_PEN; i <= LOCALBTN_TOOL_EXTRA2; ++i)
+		set_bit(i, input_dev->keybit);
+
+	input_dev->keybit[BIT_WORD(BTN_MISC)] |= BIT_MASK(BTN_0) |
+						 BIT_MASK(BTN_1) |
+						 BIT_MASK(BTN_2) |
+						 BIT_MASK(BTN_3) |
+						 BIT_MASK(BTN_4) |
+						 BIT_MASK(BTN_5);
+	/*   input_dev->keybit[BTN_MOUSE] |= BIT(BTN_LEFT); */
+	input_dev->absbit[0] |= BIT_MASK(ABS_X) | BIT_MASK(ABS_Y);
+	input_set_abs_params(input_dev, ABS_X, 0, MIMIO_XRANGE_MAX, 0, 0);
+	input_set_abs_params(input_dev, ABS_Y, 0, MIMIO_YRANGE_MAX, 0, 0);
+	input_dev->absbit[BIT_WORD(ABS_MISC)] |= BIT_MASK(ABS_MISC);
+
+#if 0
+	input_dev->absmin[ABS_X] = 0;
+	input_dev->absmin[ABS_Y] = 0;
+	input_dev->absmax[ABS_X] = 9600;
+	input_dev->absmax[ABS_Y] = 4800;
+	input_dev->absfuzz[ABS_X] = 0;
+	input_dev->absfuzz[ABS_Y] = 0;
+	input_dev->absflat[ABS_X] = 0;
+	input_dev->absflat[ABS_Y] = 0;
+#endif
+
+#if 0
+	/* this will just reduce the precision */
+	input_dev->absfuzz[ABS_X] = 8; /* experimental; may need to change */
+	input_dev->absfuzz[ABS_Y] = 8; /* experimental; may need to change */
+#endif
+
+	/*
+	 * Register the input device.
+	 */
+	res = input_register_device(mimio->idev);
+	if (res) {
+		dev_err(&udev->dev, "input_register_device failure (%d)\n",
+			res);
+		mimio_dealloc(mimio);
+		return -EIO;
+	}
+	dev_dbg(&mimio->idev->dev, "input: %s on %s (res = %d).\n",
+		input_dev->name, input_dev->phys, res);
+
+	usb_set_intfdata(ifc, mimio);
+	mimio->present = 1;
+
+	/*
+	 * Submit the input urb to the usb subsystem.
+	 */
+	mimio->in.urb->dev = mimio->udev;
+	res = usb_submit_urb(mimio->in.urb, GFP_KERNEL);
+	if (res) {
+		dev_err(&mimio->idev->dev, "usb_submit_urb failure (%d)\n",
+			res);
+		mimio_dealloc(mimio);
+		return -EIO;
+	}
+
+	/*
+	 * Attempt to greet the mimio after giving
+	 * it some post-init settling time.
+	 *
+	 * note: sometimes this sleep interval isn't
+	 * long enough to permit the device to re-init
+	 * after a hot-swap; maybe need to bump it up.
+	 *
+	 * As it is, this probably breaks module unloading support!
+	 */
+	msleep(1024);
+
+	res = mimio_greet(mimio);
+	if (res == 0) {
+		dev_dbg(&mimio->idev->dev, "Mimio greeted OK.\n");
+		mimio->greeted = 1;
+		mimio->rxhandler = mimio_rx_handler;
+	} else {
+		dev_dbg(&mimio->idev->dev, "Mimio greet Failure (%d)\n", res);
+	}
+
+	return 0;
+}
+
+static int handle_mimio_rx_penupdown(struct mimio *mimio,
+				     int down,
+				     const char *const instr[],
+				     const int instr_ofst[])
+{
+	int penid, x;
+	if (mimio->pktbuf.q - mimio->pktbuf.p < (down ? 4 : 3))
+		return 1; 		/* partial pkt */
+
+	if (down) {
+		x = *mimio->pktbuf.p ^ *(mimio->pktbuf.p + 1) ^
+			*(mimio->pktbuf.p + 2);
+		if (x != *(mimio->pktbuf.p + 3)) {
+			dev_dbg(&mimio->idev->dev, "EV_PEN%s: bad xsum.\n",
+				down ? "DOWN":"UP");
+			/* skip this event data */
+			mimio->pktbuf.p += 4;
+			/* decode any remaining events */
+			return 0;
+		}
+		penid = mimio->pktbuf.instr = *(mimio->pktbuf.p + 2);
+		if (penid > MIMIO_PEN_MAX) {
+			dev_dbg(&mimio->idev->dev,
+				"Unmapped penID (not in [0, %d]): %d\n",
+				MIMIO_PEN_MAX, (int)mimio->pktbuf.instr);
+			penid = mimio->pktbuf.instr = 0;
+		}
+		mimio->last_pen_down = penid;
+	} else {
+		penid = mimio->last_pen_down;
+	}
+	dev_dbg(&mimio->idev->dev, "%s (id %d, code %d) %s.\n", instr[penid],
+		instr_ofst[penid], penid, down ? "down" : "up");
+
+	if (instr_ofst[penid] >= 0) {
+		int code = BTN_TOOL_PEN + instr_ofst[penid];
+		int value = down ? DOWNVALUE : UPVALUE;
+		if (code > KEY_MAX)
+			dev_dbg(&mimio->idev->dev, "input_event will ignore "
+				"-- code (%d) > KEY_MAX\n", code);
+		if (!test_bit(code, mimio->idev->keybit))
+			dev_dbg(&mimio->idev->dev, "input_event will ignore "
+				"-- bit for code (%d) not enabled\n", code);
+		if (!!test_bit(code, mimio->idev->key) == value)
+			dev_dbg(&mimio->idev->dev, "input_event will ignore "
+				"-- bit for code (%d) already set to %d\n",
+				code, value);
+		if (value != DOWNVALUE) {
+			/* input_regs(mimio->idev, regs); */
+			input_report_key(mimio->idev, code, value);
+			input_sync(mimio->idev);
+		} else {
+			/* wait until we get some coordinates */
+		}
+	} else {
+		dev_dbg(&mimio->idev->dev, "penID offset[%d] == %d is < 0 "
+			"- not sending\n", penid, instr_ofst[penid]);
+	}
+	mimio->pktbuf.p += down ? 4 : 3; /* 3 for up, 4 for down */
+	return 0;
+}
+
+/*
+ * Stay tuned for partial-packet excitement.
+ *
+ * This routine buffers data packets received from the mimio device
+ * in the mimio's data space.  This buffering is necessary because
+ * the mimio's in endpoint can serve us partial packets of data, and
+ * we want the driver to support the servicing of multiple mimios.
+ * Empirical evidence gathered so far suggests that the method of
+ * buffering packet data in the mimio's data space works.  Previous
+ * versions of this driver did not buffer packet data in each mimio's
+ * data-space, and were therefore not able to service multiple mimios.
+ * Note that since the caller of this routine is running in interrupt
+ * context, care needs to be taken to ensure that this routine does not
+ * become bloated, and it may be that another spinlock is needed in each
+ * mimio to guard the buffered packet data properly.
+ */
+static void mimio_rx_handler(struct mimio *mimio,
+			     unsigned char *data,
+			     unsigned int nbytes)
+{
+	struct device *dev = &mimio->idev->dev;
+	unsigned int x;
+	unsigned int y;
+	static const char * const instr[] = {
+		"?0",
+		"black pen", "blue pen", "green pen", "red pen",
+		"brown pen", "orange pen", "purple pen", "yellow pen",
+		"big eraser", "lil eraser",
+		"?11", "?12", "?13", "?14", "?15", "?16",
+		"mimio interactive", "interactive button1",
+		"interactive button2"
+	};
+
+	/* Mimio Interactive gives:
+	 * down: [0x22 0x01 0x11 0x32 0x24]
+	 * b1  : [0x22 0x01 0x12 0x31 0x24]
+	 * b2  : [0x22 0x01 0x13 0x30 0x24]
+	 */
+	static const int instr_ofst[] = {
+		-1,
+		0, 1, 2, 3,
+		9, 9, 9, 9,
+		4, 5,
+		-1, -1, -1, -1, -1, -1,
+		6, 7, 8,
+	};
+
+	memcpy(mimio->pktbuf.q, data, nbytes);
+	mimio->pktbuf.q += nbytes;
+
+	while (mimio->pktbuf.p < mimio->pktbuf.q) {
+		int t = *mimio->pktbuf.p;
+		switch (t) {
+		case MIMIO_EV_PENUP:
+		case MIMIO_EV_PENDOWN:
+			if (handle_mimio_rx_penupdown(mimio,
+						      t == MIMIO_EV_PENDOWN,
+						      instr, instr_ofst))
+				return; /* partial packet */
+			break;
+
+		case MIMIO_EV_PENDATA:
+			if (mimio->pktbuf.q - mimio->pktbuf.p < 6)
+				/* partial pkt */
+				return;
+			x = *mimio->pktbuf.p ^ *(mimio->pktbuf.p + 1) ^
+				*(mimio->pktbuf.p + 2) ^
+				*(mimio->pktbuf.p + 3) ^
+				*(mimio->pktbuf.p + 4);
+			if (x != *(mimio->pktbuf.p + 5)) {
+				dev_dbg(dev, "EV_PENDATA: bad xsum.\n");
+				mimio->pktbuf.p += 6; /* skip this event data */
+				break; /* decode any remaining events */
+			}
+			x = *(mimio->pktbuf.p + 1);
+			x <<= 8;
+			x |= *(mimio->pktbuf.p + 2);
+			y = *(mimio->pktbuf.p + 3);
+			y <<= 8;
+			y |= *(mimio->pktbuf.p + 4);
+			dev_dbg(dev, "coord: (%d, %d)\n", x, y);
+			if (instr_ofst[mimio->pktbuf.instr] >= 0) {
+				int code = BTN_TOOL_PEN +
+					   instr_ofst[mimio->last_pen_down];
+#if 0
+				/* Utter hack to ensure we get forwarded _AND_
+				 * so we can identify when a complete signal is
+				 * received */
+				mimio->idev->abs[ABS_Y] = -1;
+				mimio->idev->abs[ABS_X] = -1;
+#endif
+				/* input_regs(mimio->idev, regs); */
+				input_report_abs(mimio->idev, ABS_X, x);
+				input_report_abs(mimio->idev, ABS_Y, y);
+				/* fake a penup */
+				change_bit(code, mimio->idev->key);
+				input_report_key(mimio->idev,
+						 code,
+						 DOWNVALUE);
+				/* always sync here */
+				mimio->idev->sync = 0;
+				input_sync(mimio->idev);
+			}
+			mimio->pktbuf.p += 6;
+			break;
+		case MIMIO_EV_MEMRESET:
+			if (mimio->pktbuf.q - mimio->pktbuf.p < 7)
+				/* partial pkt */
+				return;
+			dev_dbg(dev, "mem-reset.\n");
+			/* input_regs(mimio->idev, regs); */
+			input_event(mimio->idev, EV_KEY, BTN_0, 1);
+			input_event(mimio->idev, EV_KEY, BTN_0, 0);
+			input_sync(mimio->idev);
+			mimio->pktbuf.p += 7;
+			break;
+		case MIMIO_EV_ACC:
+			if (mimio->pktbuf.q - mimio->pktbuf.p < 4)
+				/* partial pkt */
+				return;
+			x = *mimio->pktbuf.p ^ *(mimio->pktbuf.p + 1) ^
+				*(mimio->pktbuf.p + 2);
+			if (x != *(mimio->pktbuf.p + 3)) {
+				dev_dbg(dev, "EV_ACC: bad xsum.\n");
+				mimio->pktbuf.p += 4; /* skip this event data */
+				break; /* decode any remaining events */
+			}
+			switch (*(mimio->pktbuf.p + 2)) {
+			case ACC_NEWPAGE:
+				dev_dbg(&mimio->idev->dev, "new-page.\n");
+				/* input_regs(mimio->idev, regs); */
+				input_event(mimio->idev, EV_KEY, BTN_1, 1);
+				input_event(mimio->idev, EV_KEY, BTN_1, 0);
+				input_sync(mimio->idev);
+				break;
+			case ACC_TAGPAGE:
+				dev_dbg(&mimio->idev->dev, "tag-page.\n");
+				/* input_regs(mimio->idev, regs); */
+				input_event(mimio->idev, EV_KEY, BTN_2, 1);
+				input_event(mimio->idev, EV_KEY, BTN_2, 0);
+				input_sync(mimio->idev);
+				break;
+			case ACC_PRINTPAGE:
+				dev_dbg(&mimio->idev->dev, "print-page.\n");
+				/* input_regs(mimio->idev, regs);*/
+				input_event(mimio->idev, EV_KEY, BTN_3, 1);
+				input_event(mimio->idev, EV_KEY, BTN_3, 0);
+				input_sync(mimio->idev);
+				break;
+			case ACC_MAXIMIZE:
+				dev_dbg(&mimio->idev->dev,
+					"maximize-window.\n");
+				/* input_regs(mimio->idev, regs); */
+				input_event(mimio->idev, EV_KEY, BTN_4, 1);
+				input_event(mimio->idev, EV_KEY, BTN_4, 0);
+				input_sync(mimio->idev);
+				break;
+			case ACC_FINDCTLPNL:
+				dev_dbg(&mimio->idev->dev, "find-ctl-panel.\n");
+				/* input_regs(mimio->idev, regs); */
+				input_event(mimio->idev, EV_KEY, BTN_5, 1);
+				input_event(mimio->idev, EV_KEY, BTN_5, 0);
+				input_sync(mimio->idev);
+				break;
+			case ACC_DONE:
+				dev_dbg(&mimio->idev->dev, "acc-done.\n");
+				/* no event is dispatched to the input
+				 * subsystem for this device event.
+				 */
+				break;
+			default:
+				dev_dbg(dev, "unknown acc event.\n");
+				break;
+			}
+			mimio->pktbuf.p += 4;
+			break;
+		default:
+			mimio->pktbuf.p++;
+			break;
+		}
+	}
+
+	/*
+	 * No partial event was received, so reset mimio's pktbuf ptrs.
+	 */
+	mimio->pktbuf.p = mimio->pktbuf.q = mimio->pktbuf.buf;
+}
+
+static int mimio_tx(struct mimio *mimio, const char *buf, int nbytes)
+{
+	int rslt;
+	int timeout;
+	unsigned long flags;
+	DECLARE_WAITQUEUE(wait, current);
+
+	if (!(isvalidtxsize(nbytes))) {
+		dev_err(&mimio->idev->dev, "invalid arg: nbytes: %d.\n",
+			nbytes);
+		return -EINVAL;
+	}
+
+	/*
+	 * Init the out urb and copy the data to send.
+	 */
+	mimio->out.urb->dev = mimio->udev;
+	mimio->out.urb->transfer_buffer_length = nbytes;
+	memcpy(mimio->out.urb->transfer_buffer, buf, nbytes);
+
+	/*
+	 * Send the data.
+	 */
+	spin_lock_irqsave(&mimio->txlock, flags);
+	mimio->txflags = MIMIO_TXWAIT;
+	rslt = usb_submit_urb(mimio->out.urb, GFP_ATOMIC);
+	spin_unlock_irqrestore(&mimio->txlock, flags);
+	dev_dbg(&mimio->idev->dev, "rslt: %d.\n", rslt);
+
+	if (rslt) {
+		dev_err(&mimio->idev->dev, "usb_submit_urb failure: %d.\n",
+			rslt);
+		return rslt;
+	}
+
+	/*
+	 * Wait for completion to be signalled (the mimio_irq_out
+	 * completion routine will or MIMIO_TXDONE in with txflags).
+	 */
+	timeout = HZ;
+	set_current_state(TASK_INTERRUPTIBLE);
+	add_wait_queue(&mimio->waitq, &wait);
+
+	while (timeout && ((mimio->txflags & MIMIO_TXDONE) == 0)) {
+		timeout = schedule_timeout(timeout);
+		rmb();
+	}
+
+	if ((mimio->txflags & MIMIO_TXDONE) == 0)
+		dev_dbg(&mimio->idev->dev, "tx timed out.\n");
+
+	/*
+	 * Now that completion has been signalled,
+	 * unlink the urb so that it can be recycled.
+	 */
+	set_current_state(TASK_RUNNING);
+	remove_wait_queue(&mimio->waitq, &wait);
+	usb_unlink_urb(mimio->out.urb);
+
+	return rslt;
+}
+
+static int __init mimio_init(void)
+{
+	int rslt;
+
+	rslt = usb_register(&mimio_driver);
+	if (rslt != 0) {
+		err("%s: usb_register failure: %d", __func__, rslt);
+		return rslt;
+	}
+
+	printk(KERN_INFO KBUILD_MODNAME ":"
+	       DRIVER_DESC " " DRIVER_VERSION "\n");
+	return rslt;
+}
+
+static void __exit mimio_exit(void)
+{
+	usb_deregister(&mimio_driver);
+}
+
+module_init(mimio_init);
+module_exit(mimio_exit);
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");