--- /dev/null
+/*
+ * 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/input.h>
+#include <linux/usb/input.h>
+#include <linux/slab.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 usb_interface *intf;
+ 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");
+ /* fall through */
+
+ case BATTERY_NO_REPORT:
+ case BATTERY_GOOD:
+ x = le16_to_cpup((__le16 *)&data[2]);
+ y = le16_to_cpup((__le16 *)&data[4]);
+
+ /* pen-up event */
+ 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);
+ usb_mark_last_busy(pegasus->usbdev);
+ 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);
+ int retval;
+
+ retval = usb_autopm_get_interface(pegasus->intf);
+ if (retval)
+ return retval;
+
+ pegasus->irq->dev = pegasus->usbdev;
+ if (usb_submit_urb(pegasus->irq, GFP_KERNEL))
+ retval = -EIO;
+
+ pegasus_set_mode(pegasus, PEN_MODE_XY, NOTETAKER_LED_MOUSE);
+
+ usb_autopm_put_interface(pegasus->intf);
+
+ return retval;
+}
+
+static void pegasus_close(struct input_dev *dev)
+{
+ struct pegasus *pegasus = input_get_drvdata(dev);
+ int autopm_error;
+
+ autopm_error = usb_autopm_get_interface(pegasus->intf);
+ usb_kill_urb(pegasus->irq);
+ cancel_work_sync(&pegasus->init);
+
+ if (!autopm_error)
+ usb_autopm_put_interface(pegasus->intf);
+}
+
+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;
+
+ /* 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->intf = intf;
+
+ pipe = usb_rcvintpipe(dev, endpoint->bEndpointAddress);
+ pegasus->data_len = usb_maxpacket(dev, pipe, usb_pipeout(pipe));
+
+ pegasus->data = usb_alloc_coherent(dev, pegasus->data_len, 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;
+ }
+
+ usb_fill_int_urb(pegasus->irq, dev, pipe,
+ pegasus->data, pegasus->data_len,
+ 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);
+
+ 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 int pegasus_suspend(struct usb_interface *intf, pm_message_t message)
+{
+ struct pegasus *pegasus = usb_get_intfdata(intf);
+
+ mutex_lock(&pegasus->dev->mutex);
+ usb_kill_urb(pegasus->irq);
+ mutex_unlock(&pegasus->dev->mutex);
+
+ return 0;
+}
+
+static int pegasus_resume(struct usb_interface *intf)
+{
+ struct pegasus *pegasus = usb_get_intfdata(intf);
+ int retval = 0;
+
+ mutex_lock(&pegasus->dev->mutex);
+ if (pegasus->dev->users && usb_submit_urb(pegasus->irq, GFP_NOIO) < 0)
+ retval = -EIO;
+ mutex_unlock(&pegasus->dev->mutex);
+
+ return retval;
+}
+
+static int pegasus_reset_resume(struct usb_interface *intf)
+{
+ return pegasus_resume(intf);
+}
+
+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,
+ .suspend = pegasus_suspend,
+ .resume = pegasus_resume,
+ .reset_resume = pegasus_reset_resume,
+ .id_table = pegasus_ids,
+ .supports_autosuspend = 1,
+};
+
+module_usb_driver(pegasus_driver);
+
+MODULE_AUTHOR("Martin Kepplinger <martink@posteo.de>");
+MODULE_DESCRIPTION("Pegasus Mobile Notetaker Pen tablet driver");
+MODULE_LICENSE("GPL");