================
v6 minor cleanup (thanks Dmitry)
v5 fix various bugs (thanks Oliver and Dmitry)
v4 use normal work queue instead of a kernel thread (thanks to Oliver Neukum)
v3 fix reporting low pen battery and add USB list to CC
v2 minor cleanup (remove unnecessary variables)
v1 initial release


 drivers/input/tablet/Kconfig             |  15 ++
 drivers/input/tablet/Makefile            |   1 +
 drivers/input/tablet/pegasus_notetaker.c | 364 +++++++++++++++++++++++++++++++
 3 files changed, 380 insertions(+)
 create mode 100644 drivers/input/tablet/pegasus_notetaker.c

diff --git a/drivers/input/tablet/Kconfig b/drivers/input/tablet/Kconfig
index 623bb9e..a2b9f97 100644
--- a/drivers/input/tablet/Kconfig
+++ b/drivers/input/tablet/Kconfig
@@ -73,6 +73,21 @@ config TABLET_USB_KBTAB
 	  To compile this driver as a module, choose M here: the
 	  module will be called kbtab.
 
+config TABLET_USB_PEGASUS
+	tristate "Pegasus Mobile Notetaker Pen input tablet support"
+	depends on USB_ARCH_HAS_HCD
+	select USB
+	help
+	  Say Y here if you want to use the Pegasus Mobile Notetaker,
+	  also known as:
+	  Genie e-note The Notetaker,
+	  Staedtler Digital ballpoint pen 990 01,
+	  IRISnotes Express or
+	  NEWLink Digital Note Taker.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called pegasus_notetaker.
+
 config TABLET_SERIAL_WACOM4
 	tristate "Wacom protocol 4 serial tablet support"
 	select SERIO
diff --git a/drivers/input/tablet/Makefile b/drivers/input/tablet/Makefile
index 2e13010..200fc4e 100644
--- a/drivers/input/tablet/Makefile
+++ b/drivers/input/tablet/Makefile
@@ -8,4 +8,5 @@ obj-$(CONFIG_TABLET_USB_AIPTEK)	+= aiptek.o
 obj-$(CONFIG_TABLET_USB_GTCO)	+= gtco.o
 obj-$(CONFIG_TABLET_USB_HANWANG) += hanwang.o
 obj-$(CONFIG_TABLET_USB_KBTAB)	+= kbtab.o
+obj-$(CONFIG_TABLET_USB_PEGASUS) += pegasus_notetaker.o
 obj-$(CONFIG_TABLET_SERIAL_WACOM4) += wacom_serial4.o
diff --git a/drivers/input/tablet/pegasus_notetaker.c b/drivers/input/tablet/pegasus_notetaker.c
new file mode 100644
index 0000000..8b10f29
--- /dev/null
+++ b/drivers/input/tablet/pegasus_notetaker.c
@@ -0,0 +1,364 @@
+/*
+ * Pegasus Mobile Notetaker Pen input tablet driver
+ *
+ * Copyright (c) 2016 Martin Kepplinger <martink@posteo.de>
+ */
+
+/*
+ * request packet (control endpoint):
+ * |-------------------------------------|
+ * | Report ID | Nr of bytes | command   |
+ * | (1 byte)  | (1 byte)    | (n bytes) |
+ * |-------------------------------------|
+ * | 0x02      | n           |           |
+ * |-------------------------------------|
+ *
+ * data packet after set xy mode command, 0x80 0xb5 0x02 0x01
+ * and pen is in range:
+ *
+ * byte	byte name		value (bits)
+ * --------------------------------------------
+ * 0	status			0 1 0 0 0 0 X X
+ * 1	color			0 0 0 0 H 0 S T
+ * 2	X low
+ * 3	X high
+ * 4	Y low
+ * 5	Y high
+ *
+ * X X	battery state:
+ *	no state reported	0x00
+ *	battery low		0x01
+ *	battery good		0x02
+ *
+ * H	Hovering
+ * S	Switch 1 (pen button)
+ * T	Tip
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/hid.h>
+#include <linux/usb/input.h>
+
+/* USB HID defines */
+#define USB_REQ_GET_REPORT		0x01
+#define USB_REQ_SET_REPORT		0x09
+
+#define USB_VENDOR_ID_PEGASUSTECH	0x0e20
+#define USB_DEVICE_ID_PEGASUS_NOTETAKER_EN100	0x0101
+
+/* device specific defines */
+#define NOTETAKER_REPORT_ID		0x02
+#define NOTETAKER_SET_CMD		0x80
+#define NOTETAKER_SET_MODE		0xb5
+
+#define NOTETAKER_LED_MOUSE             0x02
+#define PEN_MODE_XY                     0x01
+
+#define SPECIAL_COMMAND			0x80
+#define BUTTON_PRESSED			0xb5
+#define COMMAND_VERSION			0xa9
+
+/* in xy data packet */
+#define BATTERY_NO_REPORT		0x40
+#define BATTERY_LOW			0x41
+#define BATTERY_GOOD			0x42
+#define PEN_BUTTON_PRESSED		BIT(1)
+#define PEN_TIP				BIT(0)
+
+struct pegasus {
+	unsigned char *data;
+	u8 data_len;
+	dma_addr_t data_dma;
+	struct input_dev *dev;
+	struct usb_device *usbdev;
+	struct urb *irq;
+	char name[128];
+	char phys[64];
+	struct work_struct init;
+};
+
+static void pegasus_control_msg(struct pegasus *pegasus, u8 *data, int len)
+{
+	const int sizeof_buf = len + 2;
+	int result;
+	u8 *cmd_buf;
+
+	cmd_buf = kmalloc(sizeof_buf, GFP_KERNEL);
+	if (!cmd_buf)
+		return;
+
+	cmd_buf[0] = NOTETAKER_REPORT_ID;
+	cmd_buf[1] = len;
+	memcpy(cmd_buf + 2, data, len);
+
+	result = usb_control_msg(pegasus->usbdev,
+				 usb_sndctrlpipe(pegasus->usbdev, 0),
+				 USB_REQ_SET_REPORT,
+				 USB_TYPE_VENDOR | USB_DIR_OUT,
+				 0, 0, cmd_buf, sizeof_buf,
+				 USB_CTRL_SET_TIMEOUT);
+
+	if (result != sizeof_buf)
+		dev_err(&pegasus->usbdev->dev, "control msg error\n");
+
+	kfree(cmd_buf);
+}
+
+static void pegasus_set_mode(struct pegasus *pegasus, u8 mode, u8 led)
+{
+	u8 cmd[] = {NOTETAKER_SET_CMD, NOTETAKER_SET_MODE, led, mode};
+
+	pegasus_control_msg(pegasus, cmd, sizeof(cmd));
+}
+
+static void pegasus_parse_packet(struct pegasus *pegasus)
+{
+	unsigned char *data = pegasus->data;
+	struct input_dev *dev = pegasus->dev;
+	u16 x, y;
+
+	switch (data[0]) {
+	case SPECIAL_COMMAND:
+		/* device button pressed */
+		if (data[1] == BUTTON_PRESSED)
+			schedule_work(&pegasus->init);
+
+		break;
+	/* xy data */
+	case BATTERY_LOW:
+		dev_warn_once(&dev->dev, "Pen battery low\n");
+	case BATTERY_NO_REPORT:
+	case BATTERY_GOOD:
+		x = le16_to_cpup((__le16 *)&data[2]);
+		y = le16_to_cpup((__le16 *)&data[4]);
+
+		/* ignore pen up events */
+		if (x == 0 && y == 0)
+			break;
+
+		input_report_key(dev, BTN_TOUCH, data[1] & PEN_TIP);
+		input_report_key(dev, BTN_RIGHT, data[1] & PEN_BUTTON_PRESSED);
+		input_report_key(dev, BTN_TOOL_PEN, 1);
+		input_report_abs(dev, ABS_X, (s16)x);
+		input_report_abs(dev, ABS_Y, y);
+
+		input_sync(dev);
+		break;
+	default:
+		dev_warn_once(&pegasus->usbdev->dev,
+			      "unknown answer from device\n");
+	}
+}
+
+static void pegasus_irq(struct urb *urb)
+{
+	struct pegasus *pegasus = urb->context;
+	struct usb_device *dev = pegasus->usbdev;
+	int retval;
+
+	switch (urb->status) {
+	case 0:
+		pegasus_parse_packet(pegasus);
+		break;
+	case -ECONNRESET:
+	case -ENOENT:
+	case -ESHUTDOWN:
+		dev_err(&dev->dev, "%s - urb shutting down with status: %d",
+			__func__, urb->status);
+		return;
+	default:
+		dev_err(&dev->dev, "%s - nonzero urb status received: %d",
+			__func__, urb->status);
+		break;
+	}
+
+	retval = usb_submit_urb(urb, GFP_ATOMIC);
+	if (retval)
+		dev_err(&dev->dev, "%s - usb_submit_urb failed with result %d",
+			__func__, retval);
+}
+
+static void pegasus_init(struct work_struct *work)
+{
+	struct pegasus *pegasus = container_of(work, struct pegasus, init);
+
+	pegasus_set_mode(pegasus, PEN_MODE_XY, NOTETAKER_LED_MOUSE);
+}
+
+static int pegasus_open(struct input_dev *dev)
+{
+	struct pegasus *pegasus = input_get_drvdata(dev);
+
+	pegasus->irq->dev = pegasus->usbdev;
+	if (usb_submit_urb(pegasus->irq, GFP_KERNEL))
+		return -EIO;
+
+	return 0;
+}
+
+static void pegasus_close(struct input_dev *dev)
+{
+	struct pegasus *pegasus = input_get_drvdata(dev);
+
+	usb_kill_urb(pegasus->irq);
+	cancel_work_sync(&pegasus->init);
+}
+
+static int pegasus_probe(struct usb_interface *intf,
+			 const struct usb_device_id *id)
+{
+	struct usb_device *dev = interface_to_usbdev(intf);
+	struct usb_endpoint_descriptor *endpoint;
+	struct pegasus *pegasus;
+	struct input_dev *input_dev;
+	int error;
+	int pipe, maxp;
+
+	/* we control interface 0 */
+	if (intf->cur_altsetting->desc.bInterfaceNumber == 1)
+		return -ENODEV;
+
+	/* Sanity check that the device has an endpoint */
+	if (intf->altsetting[0].desc.bNumEndpoints < 1) {
+		dev_err(&intf->dev, "Invalid number of endpoints\n");
+		return -EINVAL;
+	}
+	endpoint = &intf->cur_altsetting->endpoint[0].desc;
+
+	pegasus = kzalloc(sizeof(*pegasus), GFP_KERNEL);
+	input_dev = input_allocate_device();
+	if (!pegasus || !input_dev) {
+		error = -ENOMEM;
+		goto err_free_mem;
+	}
+
+	pegasus->usbdev = dev;
+	pegasus->dev = input_dev;
+
+	pegasus->data = usb_alloc_coherent(dev, endpoint->wMaxPacketSize,
+					   GFP_KERNEL, &pegasus->data_dma);
+	if (!pegasus->data) {
+		error = -ENOMEM;
+		goto err_free_mem;
+	}
+
+	pegasus->irq = usb_alloc_urb(0, GFP_KERNEL);
+	if (!pegasus->irq) {
+		error = -ENOMEM;
+		goto err_free_dma;
+	}
+
+	pipe = usb_rcvintpipe(dev, endpoint->bEndpointAddress);
+	maxp = usb_maxpacket(dev, pipe, usb_pipeout(pipe));
+	pegasus->data_len = maxp;
+
+	usb_fill_int_urb(pegasus->irq, dev, pipe, pegasus->data, maxp,
+			 pegasus_irq, pegasus, endpoint->bInterval);
+
+	pegasus->irq->transfer_dma = pegasus->data_dma;
+	pegasus->irq->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+
+	if (dev->manufacturer)
+		strlcpy(pegasus->name, dev->manufacturer,
+			sizeof(pegasus->name));
+
+	if (dev->product) {
+		if (dev->manufacturer)
+			strlcat(pegasus->name, " ", sizeof(pegasus->name));
+		strlcat(pegasus->name, dev->product, sizeof(pegasus->name));
+	}
+
+	if (!strlen(pegasus->name))
+		snprintf(pegasus->name, sizeof(pegasus->name),
+			 "USB Pegasus Device %04x:%04x",
+			 le16_to_cpu(dev->descriptor.idVendor),
+			 le16_to_cpu(dev->descriptor.idProduct));
+
+	usb_make_path(dev, pegasus->phys, sizeof(pegasus->phys));
+	strlcat(pegasus->phys, "/input0", sizeof(pegasus->phys));
+
+	INIT_WORK(&pegasus->init, pegasus_init);
+
+	usb_set_intfdata(intf, pegasus);
+
+	input_dev->name = pegasus->name;
+	input_dev->phys = pegasus->phys;
+	usb_to_input_id(dev, &input_dev->id);
+	input_dev->dev.parent = &intf->dev;
+
+	input_set_drvdata(input_dev, pegasus);
+
+	input_dev->open = pegasus_open;
+	input_dev->close = pegasus_close;
+
+	__set_bit(EV_ABS, input_dev->evbit);
+	__set_bit(EV_KEY, input_dev->evbit);
+
+	__set_bit(ABS_X, input_dev->absbit);
+	__set_bit(ABS_Y, input_dev->absbit);
+
+	__set_bit(BTN_TOUCH, input_dev->keybit);
+	__set_bit(BTN_RIGHT, input_dev->keybit);
+	__set_bit(BTN_TOOL_PEN, input_dev->keybit);
+
+	__set_bit(INPUT_PROP_DIRECT, input_dev->propbit);
+	__set_bit(INPUT_PROP_POINTER, input_dev->propbit);
+
+	input_set_abs_params(input_dev, ABS_X, -1500, 1500, 8, 0);
+	input_set_abs_params(input_dev, ABS_Y, 1600, 3000, 8, 0);
+
+	pegasus_set_mode(pegasus, PEN_MODE_XY, NOTETAKER_LED_MOUSE);
+
+	error = input_register_device(pegasus->dev);
+	if (error)
+		goto err_free_urb;
+
+	return 0;
+
+err_free_urb:
+	usb_free_urb(pegasus->irq);
+err_free_dma:
+	usb_free_coherent(dev, pegasus->data_len,
+			  pegasus->data, pegasus->data_dma);
+err_free_mem:
+	input_free_device(input_dev);
+	kfree(pegasus);
+	usb_set_intfdata(intf, NULL);
+
+	return error;
+}
+
+static void pegasus_disconnect(struct usb_interface *intf)
+{
+	struct pegasus *pegasus = usb_get_intfdata(intf);
+
+	input_unregister_device(pegasus->dev);
+
+	usb_free_urb(pegasus->irq);
+	usb_free_coherent(interface_to_usbdev(intf),
+			  pegasus->data_len, pegasus->data,
+			  pegasus->data_dma);
+	kfree(pegasus);
+	usb_set_intfdata(intf, NULL);
+}
+
+static const struct usb_device_id pegasus_ids[] = {
+	{ USB_DEVICE(USB_VENDOR_ID_PEGASUSTECH,
+		     USB_DEVICE_ID_PEGASUS_NOTETAKER_EN100) },
+	{ }
+};
+MODULE_DEVICE_TABLE(usb, pegasus_ids);
+
+static struct usb_driver pegasus_driver = {
+	.name		= "pegasus_notetaker",
+	.probe		= pegasus_probe,
+	.disconnect	= pegasus_disconnect,
+	.id_table	= pegasus_ids,
+};
+
+module_usb_driver(pegasus_driver);
+
+MODULE_AUTHOR("Martin Kepplinger <martink@posteo.de>");
+MODULE_DESCRIPTION("Pegasus Mobile Notetaker Pen tablet driver");
+MODULE_LICENSE("GPL");
