/*
   * USB Synaptics device driver
   *
   *  Copyright (c) 2002 Rob Miller (rob@inpharmatica . co . uk)
   *  Copyright (c) 2003 Ron Lee (ron@debian.org)
   *	cPad driver for kernel 2.4
   *
   *  Copyright (c) 2004 Jan Steinhoff (cpad@jan-steinhoff . de)
   *  Copyright (c) 2004 Ron Lee (ron@debian.org)
   *	rewritten for kernel 2.6
   *
   *  cPad display character device part is not included. It can be found at
   *  http://jan-steinhoff.de/linux/synaptics-usb.html
   *
   * Bases on:	usb_skeleton.c v2.2 by Greg Kroah-Hartman
   *		drivers/hid/usbhid/usbmouse.c by Vojtech Pavlik
   *		drivers/input/mouse/synaptics.c by Peter Osterlund
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License as published by the Free
   * Software Foundation; either version 2 of the License, or (at your option)
   * any later version.
   *
   * Trademarks are the property of their respective owners.
   */
  
  /*
   * There are three different types of Synaptics USB devices: Touchpads,
   * touchsticks (or trackpoints), and touchscreens. Touchpads are well supported
   * by this driver, touchstick support has not been tested much yet, and
   * touchscreens have not been tested at all.
   *
   * Up to three alternate settings are possible:
   *	setting 0: one int endpoint for relative movement (used by usbhid.ko)
   *	setting 1: one int endpoint for absolute finger position
   *	setting 2 (cPad only): one int endpoint for absolute finger position and
   *		   two bulk endpoints for the display (in/out)
   * This driver uses setting 1.
   */
  
  #include <linux/kernel.h>
  #include <linux/slab.h>
  #include <linux/module.h>
  #include <linux/moduleparam.h>
  #include <linux/usb.h>
  #include <linux/input.h>
  #include <linux/usb/input.h>
  
  #define USB_VENDOR_ID_SYNAPTICS	0x06cb
  #define USB_DEVICE_ID_SYNAPTICS_TP	0x0001	/* Synaptics USB TouchPad */
  #define USB_DEVICE_ID_SYNAPTICS_INT_TP	0x0002	/* Integrated USB TouchPad */
  #define USB_DEVICE_ID_SYNAPTICS_CPAD	0x0003	/* Synaptics cPad */
  #define USB_DEVICE_ID_SYNAPTICS_TS	0x0006	/* Synaptics TouchScreen */
  #define USB_DEVICE_ID_SYNAPTICS_STICK	0x0007	/* Synaptics USB Styk */
  #define USB_DEVICE_ID_SYNAPTICS_WP	0x0008	/* Synaptics USB WheelPad */
  #define USB_DEVICE_ID_SYNAPTICS_COMP_TP	0x0009	/* Composite USB TouchPad */
  #define USB_DEVICE_ID_SYNAPTICS_WTP	0x0010	/* Wireless TouchPad */
  #define USB_DEVICE_ID_SYNAPTICS_DPAD	0x0013	/* DisplayPad */
  
  #define SYNUSB_TOUCHPAD			(1 << 0)
  #define SYNUSB_STICK			(1 << 1)
  #define SYNUSB_TOUCHSCREEN		(1 << 2)
  #define SYNUSB_AUXDISPLAY		(1 << 3) /* For cPad */
  #define SYNUSB_COMBO			(1 << 4) /* Composite device (TP + stick) */
  #define SYNUSB_IO_ALWAYS		(1 << 5)
  
  #define USB_DEVICE_SYNAPTICS(prod, kind)		\
  	USB_DEVICE(USB_VENDOR_ID_SYNAPTICS,		\
  		   USB_DEVICE_ID_SYNAPTICS_##prod),	\
  	.driver_info = (kind),
  
  #define SYNUSB_RECV_SIZE	8
  
  #define XMIN_NOMINAL		1472
  #define XMAX_NOMINAL		5472
  #define YMIN_NOMINAL		1408
  #define YMAX_NOMINAL		4448
  
  struct synusb {
  	struct usb_device *udev;
  	struct usb_interface *intf;
  	struct urb *urb;
  	unsigned char *data;
  
  	/* input device related data structures */
  	struct input_dev *input;
  	char name[128];
  	char phys[64];
  
  	/* characteristics of the device */
  	unsigned long flags;
  };
  
  static void synusb_report_buttons(struct synusb *synusb)
  {
  	struct input_dev *input_dev = synusb->input;
  
  	input_report_key(input_dev, BTN_LEFT, synusb->data[1] & 0x04);
  	input_report_key(input_dev, BTN_RIGHT, synusb->data[1] & 0x01);
  	input_report_key(input_dev, BTN_MIDDLE, synusb->data[1] & 0x02);
  }
  
  static void synusb_report_stick(struct synusb *synusb)
  {
  	struct input_dev *input_dev = synusb->input;
  	int x, y;
  	unsigned int pressure;
  
  	pressure = synusb->data[6];
  	x = (s16)(be16_to_cpup((__be16 *)&synusb->data[2]) << 3) >> 7;
  	y = (s16)(be16_to_cpup((__be16 *)&synusb->data[4]) << 3) >> 7;
  
  	if (pressure > 0) {
  		input_report_rel(input_dev, REL_X, x);
  		input_report_rel(input_dev, REL_Y, -y);
  	}
  
  	input_report_abs(input_dev, ABS_PRESSURE, pressure);
  
  	synusb_report_buttons(synusb);
  
  	input_sync(input_dev);
  }
  
  static void synusb_report_touchpad(struct synusb *synusb)
  {
  	struct input_dev *input_dev = synusb->input;
  	unsigned int num_fingers, tool_width;
  	unsigned int x, y;
  	unsigned int pressure, w;
  
  	pressure = synusb->data[6];
  	x = be16_to_cpup((__be16 *)&synusb->data[2]);
  	y = be16_to_cpup((__be16 *)&synusb->data[4]);
  	w = synusb->data[0] & 0x0f;
  
  	if (pressure > 0) {
  		num_fingers = 1;
  		tool_width = 5;
  		switch (w) {
  		case 0 ... 1:
  			num_fingers = 2 + w;
  			break;
  
  		case 2:	                /* pen, pretend its a finger */
  			break;
  
  		case 4 ... 15:
  			tool_width = w;
  			break;
  		}
  	} else {
  		num_fingers = 0;
  		tool_width = 0;
  	}
  
  	/*
  	 * Post events
  	 * BTN_TOUCH has to be first as mousedev relies on it when doing
  	 * absolute -> relative conversion
  	 */
  
  	if (pressure > 30)
  		input_report_key(input_dev, BTN_TOUCH, 1);
  	if (pressure < 25)
  		input_report_key(input_dev, BTN_TOUCH, 0);
  
  	if (num_fingers > 0) {
  		input_report_abs(input_dev, ABS_X, x);
  		input_report_abs(input_dev, ABS_Y,
  				 YMAX_NOMINAL + YMIN_NOMINAL - y);
  	}
  
  	input_report_abs(input_dev, ABS_PRESSURE, pressure);
  	input_report_abs(input_dev, ABS_TOOL_WIDTH, tool_width);
  
  	input_report_key(input_dev, BTN_TOOL_FINGER, num_fingers == 1);
  	input_report_key(input_dev, BTN_TOOL_DOUBLETAP, num_fingers == 2);
  	input_report_key(input_dev, BTN_TOOL_TRIPLETAP, num_fingers == 3);
  
  	synusb_report_buttons(synusb);
  	if (synusb->flags & SYNUSB_AUXDISPLAY)
  		input_report_key(input_dev, BTN_MIDDLE, synusb->data[1] & 0x08);
  
  	input_sync(input_dev);
  }
  
  static void synusb_irq(struct urb *urb)
  {
  	struct synusb *synusb = urb->context;
  	int error;
  
  	/* Check our status in case we need to bail out early. */
  	switch (urb->status) {
  	case 0:
  		usb_mark_last_busy(synusb->udev);
  		break;
  
  	/* Device went away so don't keep trying to read from it. */
  	case -ECONNRESET:
  	case -ENOENT:
  	case -ESHUTDOWN:
  		return;
  
  	default:
  		goto resubmit;
  		break;
  	}
  
  	if (synusb->flags & SYNUSB_STICK)
  		synusb_report_stick(synusb);
  	else
  		synusb_report_touchpad(synusb);
  
  resubmit:
  	error = usb_submit_urb(urb, GFP_ATOMIC);
  	if (error && error != -EPERM)
  		dev_err(&synusb->intf->dev,
  			"%s - usb_submit_urb failed with result: %d",
  			__func__, error);
  }
  
  static struct usb_endpoint_descriptor *
  synusb_get_in_endpoint(struct usb_host_interface *iface)
  {
  
  	struct usb_endpoint_descriptor *endpoint;
  	int i;
  
  	for (i = 0; i < iface->desc.bNumEndpoints; ++i) {
  		endpoint = &iface->endpoint[i].desc;
  
  		if (usb_endpoint_is_int_in(endpoint)) {
  			/* we found our interrupt in endpoint */
  			return endpoint;
  		}
  	}
  
  	return NULL;
  }
  
  static int synusb_open(struct input_dev *dev)
  {
  	struct synusb *synusb = input_get_drvdata(dev);
  	int retval;
  
  	retval = usb_autopm_get_interface(synusb->intf);
  	if (retval) {
  		dev_err(&synusb->intf->dev,
  			"%s - usb_autopm_get_interface failed, error: %d
  ",
  			__func__, retval);
  		return retval;
  	}
  
  	retval = usb_submit_urb(synusb->urb, GFP_KERNEL);
  	if (retval) {
  		dev_err(&synusb->intf->dev,
  			"%s - usb_submit_urb failed, error: %d
  ",
  			__func__, retval);
  		retval = -EIO;
  		goto out;
  	}
  
  	synusb->intf->needs_remote_wakeup = 1;
  
  out:
  	usb_autopm_put_interface(synusb->intf);
  	return retval;
  }
  
  static void synusb_close(struct input_dev *dev)
  {
  	struct synusb *synusb = input_get_drvdata(dev);
  	int autopm_error;
  
  	autopm_error = usb_autopm_get_interface(synusb->intf);
  
  	usb_kill_urb(synusb->urb);
  	synusb->intf->needs_remote_wakeup = 0;
  
  	if (!autopm_error)
  		usb_autopm_put_interface(synusb->intf);
  }
  
  static int synusb_probe(struct usb_interface *intf,
  			const struct usb_device_id *id)
  {
  	struct usb_device *udev = interface_to_usbdev(intf);
  	struct usb_endpoint_descriptor *ep;
  	struct synusb *synusb;
  	struct input_dev *input_dev;
  	unsigned int intf_num = intf->cur_altsetting->desc.bInterfaceNumber;
  	unsigned int altsetting = min(intf->num_altsetting, 1U);
  	int error;
  
  	error = usb_set_interface(udev, intf_num, altsetting);
  	if (error) {
  		dev_err(&udev->dev,
  			"Can not set alternate setting to %i, error: %i",
  			altsetting, error);
  		return error;
  	}
  
  	ep = synusb_get_in_endpoint(intf->cur_altsetting);
  	if (!ep)
  		return -ENODEV;
  
  	synusb = kzalloc(sizeof(*synusb), GFP_KERNEL);
  	input_dev = input_allocate_device();
  	if (!synusb || !input_dev) {
  		error = -ENOMEM;
  		goto err_free_mem;
  	}
  
  	synusb->udev = udev;
  	synusb->intf = intf;
  	synusb->input = input_dev;
  
  	synusb->flags = id->driver_info;
  	if (synusb->flags & SYNUSB_COMBO) {
  		/*
  		 * This is a combo device, we need to set proper
  		 * capability, depending on the interface.
  		 */
  		synusb->flags |= intf_num == 1 ?
  					SYNUSB_STICK : SYNUSB_TOUCHPAD;
  	}
  
  	synusb->urb = usb_alloc_urb(0, GFP_KERNEL);
  	if (!synusb->urb) {
  		error = -ENOMEM;
  		goto err_free_mem;
  	}
  
  	synusb->data = usb_alloc_coherent(udev, SYNUSB_RECV_SIZE, GFP_KERNEL,
  					  &synusb->urb->transfer_dma);
  	if (!synusb->data) {
  		error = -ENOMEM;
  		goto err_free_urb;
  	}
  
  	usb_fill_int_urb(synusb->urb, udev,
  			 usb_rcvintpipe(udev, ep->bEndpointAddress),
  			 synusb->data, SYNUSB_RECV_SIZE,
  			 synusb_irq, synusb,
  			 ep->bInterval);
  	synusb->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
  
  	if (udev->manufacturer)
  		strlcpy(synusb->name, udev->manufacturer,
  			sizeof(synusb->name));
  
  	if (udev->product) {
  		if (udev->manufacturer)
  			strlcat(synusb->name, " ", sizeof(synusb->name));
  		strlcat(synusb->name, udev->product, sizeof(synusb->name));
  	}
  
  	if (!strlen(synusb->name))
  		snprintf(synusb->name, sizeof(synusb->name),
  			 "USB Synaptics Device %04x:%04x",
  			 le16_to_cpu(udev->descriptor.idVendor),
  			 le16_to_cpu(udev->descriptor.idProduct));
  
  	if (synusb->flags & SYNUSB_STICK)
  		strlcat(synusb->name, " (Stick)", sizeof(synusb->name));
  
  	usb_make_path(udev, synusb->phys, sizeof(synusb->phys));
  	strlcat(synusb->phys, "/input0", sizeof(synusb->phys));
  
  	input_dev->name = synusb->name;
  	input_dev->phys = synusb->phys;
  	usb_to_input_id(udev, &input_dev->id);
  	input_dev->dev.parent = &synusb->intf->dev;
  
  	if (!(synusb->flags & SYNUSB_IO_ALWAYS)) {
  		input_dev->open = synusb_open;
  		input_dev->close = synusb_close;
  	}
  
  	input_set_drvdata(input_dev, synusb);
  
  	__set_bit(EV_ABS, input_dev->evbit);
  	__set_bit(EV_KEY, input_dev->evbit);
  
  	if (synusb->flags & SYNUSB_STICK) {
  		__set_bit(EV_REL, input_dev->evbit);
  		__set_bit(REL_X, input_dev->relbit);
  		__set_bit(REL_Y, input_dev->relbit);
  		__set_bit(INPUT_PROP_POINTING_STICK, input_dev->propbit);
  		input_set_abs_params(input_dev, ABS_PRESSURE, 0, 127, 0, 0);
  	} else {
  		input_set_abs_params(input_dev, ABS_X,
  				     XMIN_NOMINAL, XMAX_NOMINAL, 0, 0);
  		input_set_abs_params(input_dev, ABS_Y,
  				     YMIN_NOMINAL, YMAX_NOMINAL, 0, 0);
  		input_set_abs_params(input_dev, ABS_PRESSURE, 0, 255, 0, 0);
  		input_set_abs_params(input_dev, ABS_TOOL_WIDTH, 0, 15, 0, 0);
  		__set_bit(BTN_TOUCH, input_dev->keybit);
  		__set_bit(BTN_TOOL_FINGER, input_dev->keybit);
  		__set_bit(BTN_TOOL_DOUBLETAP, input_dev->keybit);
  		__set_bit(BTN_TOOL_TRIPLETAP, input_dev->keybit);
  	}
  
  	if (synusb->flags & SYNUSB_TOUCHSCREEN)
  		__set_bit(INPUT_PROP_DIRECT, input_dev->propbit);
  	else
  		__set_bit(INPUT_PROP_POINTER, input_dev->propbit);
  
  	__set_bit(BTN_LEFT, input_dev->keybit);
  	__set_bit(BTN_RIGHT, input_dev->keybit);
  	__set_bit(BTN_MIDDLE, input_dev->keybit);
  
  	usb_set_intfdata(intf, synusb);
  
  	if (synusb->flags & SYNUSB_IO_ALWAYS) {
  		error = synusb_open(input_dev);
  		if (error)
  			goto err_free_dma;
  	}
  
  	error = input_register_device(input_dev);
  	if (error) {
  		dev_err(&udev->dev,
  			"Failed to register input device, error %d
  ",
  			error);
  		goto err_stop_io;
  	}
  
  	return 0;
  
  err_stop_io:
  	if (synusb->flags & SYNUSB_IO_ALWAYS)
  		synusb_close(synusb->input);
  err_free_dma:
  	usb_free_coherent(udev, SYNUSB_RECV_SIZE, synusb->data,
  			  synusb->urb->transfer_dma);
  err_free_urb:
  	usb_free_urb(synusb->urb);
  err_free_mem:
  	input_free_device(input_dev);
  	kfree(synusb);
  	usb_set_intfdata(intf, NULL);
  
  	return error;
  }
  
  static void synusb_disconnect(struct usb_interface *intf)
  {
  	struct synusb *synusb = usb_get_intfdata(intf);
  	struct usb_device *udev = interface_to_usbdev(intf);
  
  	if (synusb->flags & SYNUSB_IO_ALWAYS)
  		synusb_close(synusb->input);
  
  	input_unregister_device(synusb->input);
  
  	usb_free_coherent(udev, SYNUSB_RECV_SIZE, synusb->data,
  			  synusb->urb->transfer_dma);
  	usb_free_urb(synusb->urb);
  	kfree(synusb);
  
  	usb_set_intfdata(intf, NULL);
  }
  
  static int synusb_suspend(struct usb_interface *intf, pm_message_t message)
  {
  	struct synusb *synusb = usb_get_intfdata(intf);
  	struct input_dev *input_dev = synusb->input;
  
  	mutex_lock(&input_dev->mutex);
  	usb_kill_urb(synusb->urb);
  	mutex_unlock(&input_dev->mutex);
  
  	return 0;
  }
  
  static int synusb_resume(struct usb_interface *intf)
  {
  	struct synusb *synusb = usb_get_intfdata(intf);
  	struct input_dev *input_dev = synusb->input;
  	int retval = 0;
  
  	mutex_lock(&input_dev->mutex);
  
  	if ((input_dev->users || (synusb->flags & SYNUSB_IO_ALWAYS)) &&
  	    usb_submit_urb(synusb->urb, GFP_NOIO) < 0) {
  		retval = -EIO;
  	}
  
  	mutex_unlock(&input_dev->mutex);
  
  	return retval;
  }
  
  static int synusb_pre_reset(struct usb_interface *intf)
  {
  	struct synusb *synusb = usb_get_intfdata(intf);
  	struct input_dev *input_dev = synusb->input;
  
  	mutex_lock(&input_dev->mutex);
  	usb_kill_urb(synusb->urb);
  
  	return 0;
  }
  
  static int synusb_post_reset(struct usb_interface *intf)
  {
  	struct synusb *synusb = usb_get_intfdata(intf);
  	struct input_dev *input_dev = synusb->input;
  	int retval = 0;
  
  	if ((input_dev->users || (synusb->flags & SYNUSB_IO_ALWAYS)) &&
  	    usb_submit_urb(synusb->urb, GFP_NOIO) < 0) {
  		retval = -EIO;
  	}
  
  	mutex_unlock(&input_dev->mutex);
  
  	return retval;
  }
  
  static int synusb_reset_resume(struct usb_interface *intf)
  {
  	return synusb_resume(intf);
  }
  
  static struct usb_device_id synusb_idtable[] = {
  	{ USB_DEVICE_SYNAPTICS(TP, SYNUSB_TOUCHPAD) },
  	{ USB_DEVICE_SYNAPTICS(INT_TP, SYNUSB_TOUCHPAD) },
  	{ USB_DEVICE_SYNAPTICS(CPAD,
  		SYNUSB_TOUCHPAD | SYNUSB_AUXDISPLAY | SYNUSB_IO_ALWAYS) },
  	{ USB_DEVICE_SYNAPTICS(TS, SYNUSB_TOUCHSCREEN) },
  	{ USB_DEVICE_SYNAPTICS(STICK, SYNUSB_STICK) },
  	{ USB_DEVICE_SYNAPTICS(WP, SYNUSB_TOUCHPAD) },
  	{ USB_DEVICE_SYNAPTICS(COMP_TP, SYNUSB_COMBO) },
  	{ USB_DEVICE_SYNAPTICS(WTP, SYNUSB_TOUCHPAD) },
  	{ USB_DEVICE_SYNAPTICS(DPAD, SYNUSB_TOUCHPAD) },
  	{ }
  };
  MODULE_DEVICE_TABLE(usb, synusb_idtable);
  
  static struct usb_driver synusb_driver = {
  	.name		= "synaptics_usb",
  	.probe		= synusb_probe,
  	.disconnect	= synusb_disconnect,
  	.id_table	= synusb_idtable,
  	.suspend	= synusb_suspend,
  	.resume		= synusb_resume,
  	.pre_reset	= synusb_pre_reset,
  	.post_reset	= synusb_post_reset,
  	.reset_resume	= synusb_reset_resume,
  	.supports_autosuspend = 1,
  };
  
  module_usb_driver(synusb_driver);
  
  MODULE_AUTHOR("Rob Miller <rob@inpharmatica.co.uk>, "
                "Ron Lee <ron@debian.org>, "
                "Jan Steinhoff <cpad@jan-steinhoff.de>");
  MODULE_DESCRIPTION("Synaptics USB device driver");
  MODULE_LICENSE("GPL");