leetmouse.c

/*
 *  Copyright (c) 1999-2001 Vojtech Pavlik
 *
 *  USB HIDBP Mouse support
 */

/*
 * 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.
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * Should you need to contact me, the author, you can do so either by
 * e-mail - mail your message to <vojtech@ucw.cz>, or by paper mail:
 * Vojtech Pavlik, Simunkova 1594, Prague 8, 182 00 Czech Republic
 */

/*
 * Your mouse's polling rate.
 * If you don't know what yours is, follow this link:
 * https://wiki.archlinux.org/index.php/Mouse_polling_rate
 */
#define POLLING_RATE 125

/*
 * This should be your desired acceleration. It needs to end with an f.
 * For example, setting this to "0.1f" should be equal to
 * cl_mouseaccel 0.1 in Quake.
 */
#define ACCELERATION 0.2f

#define SENSITIVITY 1.0f
#define SENS_CAP 0.0f
#define OFFSET 0.0f
#define PRE_SCALE_X 1.0f
#define PRE_SCALE_Y 1.0f
#define POST_SCALE_X 1.0f
#define POST_SCALE_Y 1.0f
#define SPEED_CAP 0.0f


#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/usb/input.h>
#include <linux/hid.h>

/*
 * Version Information
 */
#define DRIVER_VERSION "v1.6a"
#define DRIVER_AUTHOR "Vojtech Pavlik <vojtech@ucw.cz>"
#define DRIVER_DESC "USB HID Boot Protocol mouse driver with acceleration"
#define DRIVER_LICENSE "GPL"

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE(DRIVER_LICENSE);

struct usb_mouse {
	char name[128];
	char phys[64];
	struct usb_device *usbdev;
	struct input_dev *dev;
	struct urb *irq;

	signed char *data;
	dma_addr_t data_dma;
};

static inline int Leet_round(float x)
{
	if (x >= 0) {
		return (int)(x + 0.5f);
	} else {
		return (int)(x - 0.5f);
	}
}

// What do we have here? Code from Quake 3, which is also GPL.
// https://en.wikipedia.org/wiki/Fast_inverse_square_root
// Copyright (C) 1999-2005 Id Software, Inc.
static inline float Q_sqrt(float number)
{
	long i;
	float x2, y;
	const float threehalfs = 1.5F;

	x2 = number * 0.5F;
	y  = number;
	i  = * ( long * ) &y;                       // evil floating point bit level hacking
	i  = 0x5f3759df - ( i >> 1 );               // what the fuck?
	y  = * ( float * ) &i;
	y  = y * ( threehalfs - ( x2 * y * y ) );   // 1st iteration
//	y  = y * ( threehalfs - ( x2 * y * y ) );   // 2nd iteration, this can be removed

	return 1 / y;
}

static void usb_mouse_irq(struct urb *urb)
{
	struct usb_mouse *mouse = urb->context;
	signed char *data = mouse->data;
	struct input_dev *dev = mouse->dev;
	int status;

	// acceleration happens here
	float delta_x = data[1] * PRE_SCALE_X;
	float delta_y = data[2] * PRE_SCALE_Y;
	float ms = 1000.0f / POLLING_RATE;
	float accel_sens = SENSITIVITY;
	float rate = Q_sqrt(delta_x * delta_x + delta_y * delta_y);
	static float carry_x = 0.0f;
	static float carry_y = 0.0f;

	if (SPEED_CAP != 0) {
		if (rate >= SPEED_CAP) {
			delta_x *= SPEED_CAP / rate;
			delta_y *= SPEED_CAP / rate;
		}
	}
	rate /= ms;
	rate -= OFFSET;
	if (rate > 0) {
		rate *= ACCELERATION;
		accel_sens += rate;
	}
	if (SENS_CAP > 0 && accel_sens >= SENS_CAP) {
		accel_sens = SENS_CAP;
	}
	accel_sens /= SENSITIVITY;
	delta_x *= accel_sens;
	delta_y *= accel_sens;
	delta_x *= POST_SCALE_X;
	delta_y *= POST_SCALE_Y;
	delta_x += carry_x;
	delta_y += carry_y;
	carry_x = delta_x - Leet_round(delta_x);
	carry_y = delta_y - Leet_round(delta_y);

	switch (urb->status) {
	case 0:			/* success */
		break;
	case -ECONNRESET:	/* unlink */
	case -ENOENT:
	case -ESHUTDOWN:
		return;
	/* -EPIPE:  should clear the halt */
	default:		/* error */
		goto resubmit;
	}

	input_report_key(dev, BTN_LEFT,   data[0] & 0x01);
	input_report_key(dev, BTN_RIGHT,  data[0] & 0x02);
	input_report_key(dev, BTN_MIDDLE, data[0] & 0x04);
	input_report_key(dev, BTN_SIDE,   data[0] & 0x08);
	input_report_key(dev, BTN_EXTRA,  data[0] & 0x10);

	input_report_rel(dev, REL_X,     Leet_round(delta_x));
	input_report_rel(dev, REL_Y,     Leet_round(delta_y));
	input_report_rel(dev, REL_WHEEL, data[3]);

	input_sync(dev);
resubmit:
	status = usb_submit_urb (urb, GFP_ATOMIC);
	if (status)
		dev_err(&mouse->usbdev->dev,
			"can't resubmit intr, %s-%s/input0, status %d\n",
			mouse->usbdev->bus->bus_name,
			mouse->usbdev->devpath, status);
}

static int usb_mouse_open(struct input_dev *dev)
{
	struct usb_mouse *mouse = input_get_drvdata(dev);

	mouse->irq->dev = mouse->usbdev;
	if (usb_submit_urb(mouse->irq, GFP_KERNEL))
		return -EIO;

	return 0;
}

static void usb_mouse_close(struct input_dev *dev)
{
	struct usb_mouse *mouse = input_get_drvdata(dev);

	usb_kill_urb(mouse->irq);
}

static int usb_mouse_probe(struct usb_interface *intf, const struct usb_device_id *id)
{
	struct usb_device *dev = interface_to_usbdev(intf);
	struct usb_host_interface *interface;
	struct usb_endpoint_descriptor *endpoint;
	struct usb_mouse *mouse;
	struct input_dev *input_dev;
	int pipe, maxp;
	int error = -ENOMEM;

	interface = intf->cur_altsetting;

	if (interface->desc.bNumEndpoints != 1)
		return -ENODEV;

	endpoint = &interface->endpoint[0].desc;
	if (!usb_endpoint_is_int_in(endpoint))
		return -ENODEV;

	pipe = usb_rcvintpipe(dev, endpoint->bEndpointAddress);
	maxp = usb_maxpacket(dev, pipe, usb_pipeout(pipe));

	mouse = kzalloc(sizeof(struct usb_mouse), GFP_KERNEL);
	input_dev = input_allocate_device();
	if (!mouse || !input_dev)
		goto fail1;

	mouse->data = usb_alloc_coherent(dev, 8, GFP_ATOMIC, &mouse->data_dma);
	if (!mouse->data)
		goto fail1;

	mouse->irq = usb_alloc_urb(0, GFP_KERNEL);
	if (!mouse->irq)
		goto fail2;

	mouse->usbdev = dev;
	mouse->dev = input_dev;

	if (dev->manufacturer)
		strlcpy(mouse->name, dev->manufacturer, sizeof(mouse->name));

	if (dev->product) {
		if (dev->manufacturer)
			strlcat(mouse->name, " ", sizeof(mouse->name));
		strlcat(mouse->name, dev->product, sizeof(mouse->name));
	}

	if (!strlen(mouse->name))
		snprintf(mouse->name, sizeof(mouse->name),
			 "USB HIDBP Mouse %04x:%04x",
			 le16_to_cpu(dev->descriptor.idVendor),
			 le16_to_cpu(dev->descriptor.idProduct));

	usb_make_path(dev, mouse->phys, sizeof(mouse->phys));
	strlcat(mouse->phys, "/input0", sizeof(mouse->phys));

	input_dev->name = mouse->name;
	input_dev->phys = mouse->phys;
	usb_to_input_id(dev, &input_dev->id);
	input_dev->dev.parent = &intf->dev;

	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL);
	input_dev->keybit[BIT_WORD(BTN_MOUSE)] = BIT_MASK(BTN_LEFT) |
		BIT_MASK(BTN_RIGHT) | BIT_MASK(BTN_MIDDLE);
	input_dev->relbit[0] = BIT_MASK(REL_X) | BIT_MASK(REL_Y);
	input_dev->keybit[BIT_WORD(BTN_MOUSE)] |= BIT_MASK(BTN_SIDE) |
		BIT_MASK(BTN_EXTRA);
	input_dev->relbit[0] |= BIT_MASK(REL_WHEEL);

	input_set_drvdata(input_dev, mouse);

	input_dev->open = usb_mouse_open;
	input_dev->close = usb_mouse_close;

	usb_fill_int_urb(mouse->irq, dev, pipe, mouse->data,
			 (maxp > 8 ? 8 : maxp),
			 usb_mouse_irq, mouse, endpoint->bInterval);
	mouse->irq->transfer_dma = mouse->data_dma;
	mouse->irq->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;

	error = input_register_device(mouse->dev);
	if (error)
		goto fail3;

	usb_set_intfdata(intf, mouse);
	return 0;

fail3:
	usb_free_urb(mouse->irq);
fail2:
	usb_free_coherent(dev, 8, mouse->data, mouse->data_dma);
fail1:
	input_free_device(input_dev);
	kfree(mouse);
	return error;
}

static void usb_mouse_disconnect(struct usb_interface *intf)
{
	struct usb_mouse *mouse = usb_get_intfdata (intf);

	usb_set_intfdata(intf, NULL);
	if (mouse) {
		usb_kill_urb(mouse->irq);
		input_unregister_device(mouse->dev);
		usb_free_urb(mouse->irq);
		usb_free_coherent(interface_to_usbdev(intf), 8, mouse->data, mouse->data_dma);
		kfree(mouse);
	}
}

static struct usb_device_id usb_mouse_id_table [] = {
	{ USB_INTERFACE_INFO(USB_INTERFACE_CLASS_HID, USB_INTERFACE_SUBCLASS_BOOT,
		USB_INTERFACE_PROTOCOL_MOUSE) },
	{ }	/* Terminating entry */
};

MODULE_DEVICE_TABLE (usb, usb_mouse_id_table);

static struct usb_driver usb_mouse_driver = {
	.name		= "leetmouse",
	.probe		= usb_mouse_probe,
	.disconnect	= usb_mouse_disconnect,
	.id_table	= usb_mouse_id_table,
};

module_usb_driver(usb_mouse_driver);