mousedev.c

来自「linux 内核源代码」· C语言 代码 · 共 1,104 行 · 第 1/2 页

/*
 * Input driver to ExplorerPS/2 device driver module.
 *
 * Copyright (c) 1999-2002 Vojtech Pavlik
 * Copyright (c) 2004      Dmitry Torokhov
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 */

#define MOUSEDEV_MINOR_BASE	32
#define MOUSEDEV_MINORS		32
#define MOUSEDEV_MIX		31

#include <linux/slab.h>
#include <linux/poll.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/input.h>
#include <linux/random.h>
#include <linux/major.h>
#include <linux/device.h>
#ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
#include <linux/miscdevice.h>
#endif

MODULE_AUTHOR("Vojtech Pavlik <[e-mail]>");
MODULE_DESCRIPTION("Mouse (ExplorerPS/2) device interfaces");
MODULE_LICENSE("GPL");

#ifndef CONFIG_INPUT_MOUSEDEV_SCREEN_X
#define CONFIG_INPUT_MOUSEDEV_SCREEN_X	1024
#endif
#ifndef CONFIG_INPUT_MOUSEDEV_SCREEN_Y
#define CONFIG_INPUT_MOUSEDEV_SCREEN_Y	768
#endif

static int xres = CONFIG_INPUT_MOUSEDEV_SCREEN_X;
module_param(xres, uint, 0644);
MODULE_PARM_DESC(xres, "Horizontal screen resolution");

static int yres = CONFIG_INPUT_MOUSEDEV_SCREEN_Y;
module_param(yres, uint, 0644);
MODULE_PARM_DESC(yres, "Vertical screen resolution");

static unsigned tap_time = 200;
module_param(tap_time, uint, 0644);
MODULE_PARM_DESC(tap_time, "Tap time for touchpads in absolute mode (msecs)");

struct mousedev_hw_data {
	int dx, dy, dz;
	int x, y;
	int abs_event;
	unsigned long buttons;
};

struct mousedev {
	int exist;
	int open;
	int minor;
	char name[16];
	struct input_handle handle;
	wait_queue_head_t wait;
	struct list_head client_list;
	spinlock_t client_lock; /* protects client_list */
	struct mutex mutex;
	struct device dev;

	struct list_head mixdev_node;
	int mixdev_open;

	struct mousedev_hw_data packet;
	unsigned int pkt_count;
	int old_x[4], old_y[4];
	int frac_dx, frac_dy;
	unsigned long touch;
};

enum mousedev_emul {
	MOUSEDEV_EMUL_PS2,
	MOUSEDEV_EMUL_IMPS,
	MOUSEDEV_EMUL_EXPS
};

struct mousedev_motion {
	int dx, dy, dz;
	unsigned long buttons;
};

#define PACKET_QUEUE_LEN	16
struct mousedev_client {
	struct fasync_struct *fasync;
	struct mousedev *mousedev;
	struct list_head node;

	struct mousedev_motion packets[PACKET_QUEUE_LEN];
	unsigned int head, tail;
	spinlock_t packet_lock;
	int pos_x, pos_y;

	signed char ps2[6];
	unsigned char ready, buffer, bufsiz;
	unsigned char imexseq, impsseq;
	enum mousedev_emul mode;
	unsigned long last_buttons;
};

#define MOUSEDEV_SEQ_LEN	6

static unsigned char mousedev_imps_seq[] = { 0xf3, 200, 0xf3, 100, 0xf3, 80 };
static unsigned char mousedev_imex_seq[] = { 0xf3, 200, 0xf3, 200, 0xf3, 80 };

static struct input_handler mousedev_handler;

static struct mousedev *mousedev_table[MOUSEDEV_MINORS];
static DEFINE_MUTEX(mousedev_table_mutex);
static struct mousedev *mousedev_mix;
static LIST_HEAD(mousedev_mix_list);

static void mixdev_open_devices(void);
static void mixdev_close_devices(void);

#define fx(i)  (mousedev->old_x[(mousedev->pkt_count - (i)) & 03])
#define fy(i)  (mousedev->old_y[(mousedev->pkt_count - (i)) & 03])

static void mousedev_touchpad_event(struct input_dev *dev,
				    struct mousedev *mousedev,
				    unsigned int code, int value)
{
	int size, tmp;
	enum { FRACTION_DENOM = 128 };

	switch (code) {

	case ABS_X:
		fx(0) = value;
		if (mousedev->touch && mousedev->pkt_count >= 2) {
			size = dev->absmax[ABS_X] - dev->absmin[ABS_X];
			if (size == 0)
				size = 256 * 2;
			tmp = ((value - fx(2)) * 256 * FRACTION_DENOM) / size;
			tmp += mousedev->frac_dx;
			mousedev->packet.dx = tmp / FRACTION_DENOM;
			mousedev->frac_dx =
				tmp - mousedev->packet.dx * FRACTION_DENOM;
		}
		break;

	case ABS_Y:
		fy(0) = value;
		if (mousedev->touch && mousedev->pkt_count >= 2) {
			/* use X size to keep the same scale */
			size = dev->absmax[ABS_X] - dev->absmin[ABS_X];
			if (size == 0)
				size = 256 * 2;
			tmp = -((value - fy(2)) * 256 * FRACTION_DENOM) / size;
			tmp += mousedev->frac_dy;
			mousedev->packet.dy = tmp / FRACTION_DENOM;
			mousedev->frac_dy = tmp -
				mousedev->packet.dy * FRACTION_DENOM;
		}
		break;
	}
}

static void mousedev_abs_event(struct input_dev *dev, struct mousedev *mousedev,
				unsigned int code, int value)
{
	int size;

	switch (code) {

	case ABS_X:
		size = dev->absmax[ABS_X] - dev->absmin[ABS_X];
		if (size == 0)
			size = xres ? : 1;
		if (value > dev->absmax[ABS_X])
			value = dev->absmax[ABS_X];
		if (value < dev->absmin[ABS_X])
			value = dev->absmin[ABS_X];
		mousedev->packet.x =
			((value - dev->absmin[ABS_X]) * xres) / size;
		mousedev->packet.abs_event = 1;
		break;

	case ABS_Y:
		size = dev->absmax[ABS_Y] - dev->absmin[ABS_Y];
		if (size == 0)
			size = yres ? : 1;
		if (value > dev->absmax[ABS_Y])
			value = dev->absmax[ABS_Y];
		if (value < dev->absmin[ABS_Y])
			value = dev->absmin[ABS_Y];
		mousedev->packet.y = yres -
			((value - dev->absmin[ABS_Y]) * yres) / size;
		mousedev->packet.abs_event = 1;
		break;
	}
}

static void mousedev_rel_event(struct mousedev *mousedev,
				unsigned int code, int value)
{
	switch (code) {
	case REL_X:
		mousedev->packet.dx += value;
		break;

	case REL_Y:
		mousedev->packet.dy -= value;
		break;

	case REL_WHEEL:
		mousedev->packet.dz -= value;
		break;
	}
}

static void mousedev_key_event(struct mousedev *mousedev,
				unsigned int code, int value)
{
	int index;

	switch (code) {

	case BTN_TOUCH:
	case BTN_0:
	case BTN_LEFT:		index = 0; break;

	case BTN_STYLUS:
	case BTN_1:
	case BTN_RIGHT:		index = 1; break;

	case BTN_2:
	case BTN_FORWARD:
	case BTN_STYLUS2:
	case BTN_MIDDLE:	index = 2; break;

	case BTN_3:
	case BTN_BACK:
	case BTN_SIDE:		index = 3; break;

	case BTN_4:
	case BTN_EXTRA:		index = 4; break;

	default:		return;
	}

	if (value) {
		set_bit(index, &mousedev->packet.buttons);
		set_bit(index, &mousedev_mix->packet.buttons);
	} else {
		clear_bit(index, &mousedev->packet.buttons);
		clear_bit(index, &mousedev_mix->packet.buttons);
	}
}

static void mousedev_notify_readers(struct mousedev *mousedev,
				    struct mousedev_hw_data *packet)
{
	struct mousedev_client *client;
	struct mousedev_motion *p;
	unsigned int new_head;
	int wake_readers = 0;

	rcu_read_lock();
	list_for_each_entry_rcu(client, &mousedev->client_list, node) {

		/* Just acquire the lock, interrupts already disabled */
		spin_lock(&client->packet_lock);

		p = &client->packets[client->head];
		if (client->ready && p->buttons != mousedev->packet.buttons) {
			new_head = (client->head + 1) % PACKET_QUEUE_LEN;
			if (new_head != client->tail) {
				p = &client->packets[client->head = new_head];
				memset(p, 0, sizeof(struct mousedev_motion));
			}
		}

		if (packet->abs_event) {
			p->dx += packet->x - client->pos_x;
			p->dy += packet->y - client->pos_y;
			client->pos_x = packet->x;
			client->pos_y = packet->y;
		}

		client->pos_x += packet->dx;
		client->pos_x = client->pos_x < 0 ?
			0 : (client->pos_x >= xres ? xres : client->pos_x);
		client->pos_y += packet->dy;
		client->pos_y = client->pos_y < 0 ?
			0 : (client->pos_y >= yres ? yres : client->pos_y);

		p->dx += packet->dx;
		p->dy += packet->dy;
		p->dz += packet->dz;
		p->buttons = mousedev->packet.buttons;

		if (p->dx || p->dy || p->dz ||
		    p->buttons != client->last_buttons)
			client->ready = 1;

		spin_unlock(&client->packet_lock);

		if (client->ready) {
			kill_fasync(&client->fasync, SIGIO, POLL_IN);
			wake_readers = 1;
		}
	}
	rcu_read_unlock();

	if (wake_readers)
		wake_up_interruptible(&mousedev->wait);
}

static void mousedev_touchpad_touch(struct mousedev *mousedev, int value)
{
	if (!value) {
		if (mousedev->touch &&
		    time_before(jiffies,
				mousedev->touch + msecs_to_jiffies(tap_time))) {
			/*
			 * Toggle left button to emulate tap.
			 * We rely on the fact that mousedev_mix always has 0
			 * motion packet so we won't mess current position.
			 */
			set_bit(0, &mousedev->packet.buttons);
			set_bit(0, &mousedev_mix->packet.buttons);
			mousedev_notify_readers(mousedev, &mousedev_mix->packet);
			mousedev_notify_readers(mousedev_mix,
						&mousedev_mix->packet);
			clear_bit(0, &mousedev->packet.buttons);
			clear_bit(0, &mousedev_mix->packet.buttons);
		}
		mousedev->touch = mousedev->pkt_count = 0;
		mousedev->frac_dx = 0;
		mousedev->frac_dy = 0;

	} else if (!mousedev->touch)
		mousedev->touch = jiffies;
}

static void mousedev_event(struct input_handle *handle,
			   unsigned int type, unsigned int code, int value)
{
	struct mousedev *mousedev = handle->private;

	switch (type) {

	case EV_ABS:
		/* Ignore joysticks */
		if (test_bit(BTN_TRIGGER, handle->dev->keybit))
			return;

		if (test_bit(BTN_TOOL_FINGER, handle->dev->keybit))
			mousedev_touchpad_event(handle->dev,
						mousedev, code, value);
		else
			mousedev_abs_event(handle->dev, mousedev, code, value);

		break;

	case EV_REL:
		mousedev_rel_event(mousedev, code, value);
		break;

	case EV_KEY:
		if (value != 2) {
			if (code == BTN_TOUCH &&
			    test_bit(BTN_TOOL_FINGER, handle->dev->keybit))
				mousedev_touchpad_touch(mousedev, value);
			else
				mousedev_key_event(mousedev, code, value);
		}
		break;

	case EV_SYN:
		if (code == SYN_REPORT) {
			if (mousedev->touch) {
				mousedev->pkt_count++;
				/*
				 * Input system eats duplicate events,
				 * but we need all of them to do correct
				 * averaging so apply present one forward
				 */
				fx(0) = fx(1);
				fy(0) = fy(1);
			}

			mousedev_notify_readers(mousedev, &mousedev->packet);
			mousedev_notify_readers(mousedev_mix, &mousedev->packet);

			mousedev->packet.dx = mousedev->packet.dy =
				mousedev->packet.dz = 0;
			mousedev->packet.abs_event = 0;
		}
		break;
	}
}

static int mousedev_fasync(int fd, struct file *file, int on)
{
	int retval;
	struct mousedev_client *client = file->private_data;

	retval = fasync_helper(fd, file, on, &client->fasync);

	return retval < 0 ? retval : 0;
}

static void mousedev_free(struct device *dev)
{
	struct mousedev *mousedev = container_of(dev, struct mousedev, dev);

	kfree(mousedev);
}

static int mousedev_open_device(struct mousedev *mousedev)
{
	int retval;

	retval = mutex_lock_interruptible(&mousedev->mutex);
	if (retval)
		return retval;

	if (mousedev->minor == MOUSEDEV_MIX)
		mixdev_open_devices();
	else if (!mousedev->exist)
		retval = -ENODEV;
	else if (!mousedev->open++) {
		retval = input_open_device(&mousedev->handle);
		if (retval)
			mousedev->open--;
	}

	mutex_unlock(&mousedev->mutex);
	return retval;
}

static void mousedev_close_device(struct mousedev *mousedev)
{
	mutex_lock(&mousedev->mutex);

	if (mousedev->minor == MOUSEDEV_MIX)
		mixdev_close_devices();
	else if (mousedev->exist && !--mousedev->open)
		input_close_device(&mousedev->handle);

	mutex_unlock(&mousedev->mutex);
}

/*
 * Open all available devices so they can all be multiplexed in one.
 * stream. Note that this function is called with mousedev_mix->mutex
 * held.
 */
static void mixdev_open_devices(void)
{
	struct mousedev *mousedev;

	if (mousedev_mix->open++)
		return;

	list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) {
		if (!mousedev->mixdev_open) {
			if (mousedev_open_device(mousedev))
				continue;

			mousedev->mixdev_open = 1;
		}
	}
}

/*
 * Close all devices that were opened as part of multiplexed
 * device. Note that this function is called with mousedev_mix->mutex
 * held.
 */
static void mixdev_close_devices(void)
{
	struct mousedev *mousedev;

	if (--mousedev_mix->open)
		return;

	list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) {
		if (mousedev->mixdev_open) {
			mousedev->mixdev_open = 0;
			mousedev_close_device(mousedev);
		}
	}
}


static void mousedev_attach_client(struct mousedev *mousedev,
				   struct mousedev_client *client)
{
	spin_lock(&mousedev->client_lock);
	list_add_tail_rcu(&client->node, &mousedev->client_list);
	spin_unlock(&mousedev->client_lock);
	synchronize_rcu();
}

static void mousedev_detach_client(struct mousedev *mousedev,
				   struct mousedev_client *client)
{
	spin_lock(&mousedev->client_lock);
	list_del_rcu(&client->node);
	spin_unlock(&mousedev->client_lock);
	synchronize_rcu();
}

static int mousedev_release(struct inode *inode, struct file *file)
{
	struct mousedev_client *client = file->private_data;
	struct mousedev *mousedev = client->mousedev;

	mousedev_fasync(-1, file, 0);
	mousedev_detach_client(mousedev, client);
	kfree(client);

	mousedev_close_device(mousedev);
	put_device(&mousedev->dev);

	return 0;
}

static int mousedev_open(struct inode *inode, struct file *file)
{
	struct mousedev_client *client;
	struct mousedev *mousedev;
	int error;
	int i;

#ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
	if (imajor(inode) == MISC_MAJOR)
		i = MOUSEDEV_MIX;
	else
#endif
		i = iminor(inode) - MOUSEDEV_MINOR_BASE;

	if (i >= MOUSEDEV_MINORS)
		return -ENODEV;

	error = mutex_lock_interruptible(&mousedev_table_mutex);
	if (error)
		return error;
	mousedev = mousedev_table[i];
	if (mousedev)