Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1125 insertions, 0 deletions

diff --git a/drivers/input/mousedev.c b/drivers/input/mousedev.c
new file mode 100644
index 000000000..505c562a5
--- /dev/null
+++ b/drivers/input/mousedev.c
@@ -0,0 +1,1125 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Input driver to ExplorerPS/2 device driver module.
+ *
+ * Copyright (c) 1999-2002 Vojtech Pavlik
+ * Copyright (c) 2004      Dmitry Torokhov
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#define MOUSEDEV_MINOR_BASE	32
+#define MOUSEDEV_MINORS		31
+#define MOUSEDEV_MIX		63
+
+#include <linux/bitops.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/poll.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/input.h>
+#include <linux/random.h>
+#include <linux/major.h>
+#include <linux/device.h>
+#include <linux/cdev.h>
+#include <linux/kernel.h>
+
+MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
+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 open;
+	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 cdev cdev;
+	bool exist;
+
+	struct list_head mixdev_node;
+	bool opened_by_mixdev;
+
+	struct mousedev_hw_data packet;
+	unsigned int pkt_count;
+	int old_x[4], old_y[4];
+	int frac_dx, frac_dy;
+	unsigned long touch;
+
+	int (*open_device)(struct mousedev *mousedev);
+	void (*close_device)(struct mousedev *mousedev);
+};
+
+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;
+
+	u8 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 mousedev *mousedev_mix;
+static LIST_HEAD(mousedev_mix_list);
+
+#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 = input_abs_get_max(dev, ABS_X) -
+					input_abs_get_min(dev, 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 for ABS_Y to keep the same scale */
+			size = input_abs_get_max(dev, ABS_X) -
+					input_abs_get_min(dev, 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 min, max, size;
+
+	switch (code) {
+
+	case ABS_X:
+		min = input_abs_get_min(dev, ABS_X);
+		max = input_abs_get_max(dev, ABS_X);
+
+		size = max - min;
+		if (size == 0)
+			size = xres ? : 1;
+
+		value = clamp(value, min, max);
+
+		mousedev->packet.x = ((value - min) * xres) / size;
+		mousedev->packet.abs_event = 1;
+		break;
+
+	case ABS_Y:
+		min = input_abs_get_min(dev, ABS_Y);
+		max = input_abs_get_max(dev, ABS_Y);
+
+		size = max - min;
+		if (size == 0)
+			size = yres ? : 1;
+
+		value = clamp(value, min, max);
+
+		mousedev->packet.y = yres - ((value - min) * 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 = clamp_val(client->pos_x, 0, xres);
+
+		client->pos_y += packet->dy;
+		client->pos_y = clamp_val(client->pos_y, 0, yres);
+
+		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)
+{
+	struct mousedev_client *client = file->private_data;
+
+	return fasync_helper(fd, file, on, &client->fasync);
+}
+
+static void mousedev_free(struct device *dev)
+{
+	struct mousedev *mousedev = container_of(dev, struct mousedev, dev);
+
+	input_put_device(mousedev->handle.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->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->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 int mixdev_open_devices(struct mousedev *mixdev)
+{
+	int error;
+
+	error = mutex_lock_interruptible(&mixdev->mutex);
+	if (error)
+		return error;
+
+	if (!mixdev->open++) {
+		struct mousedev *mousedev;
+
+		list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) {
+			if (!mousedev->opened_by_mixdev) {
+				if (mousedev_open_device(mousedev))
+					continue;
+
+				mousedev->opened_by_mixdev = true;
+			}
+		}
+	}
+
+	mutex_unlock(&mixdev->mutex);
+	return 0;
+}
+
+/*
+ * 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(struct mousedev *mixdev)
+{
+	mutex_lock(&mixdev->mutex);
+
+	if (!--mixdev->open) {
+		struct mousedev *mousedev;
+
+		list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) {
+			if (mousedev->opened_by_mixdev) {
+				mousedev->opened_by_mixdev = false;
+				mousedev_close_device(mousedev);
+			}
+		}
+	}
+
+	mutex_unlock(&mixdev->mutex);
+}
+
+
+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);
+}
+
+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_detach_client(mousedev, client);
+	kfree(client);
+
+	mousedev->close_device(mousedev);
+
+	return 0;
+}
+
+static int mousedev_open(struct inode *inode, struct file *file)
+{
+	struct mousedev_client *client;
+	struct mousedev *mousedev;
+	int error;
+
+#ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
+	if (imajor(inode) == MISC_MAJOR)
+		mousedev = mousedev_mix;
+	else
+#endif
+		mousedev = container_of(inode->i_cdev, struct mousedev, cdev);
+
+	client = kzalloc(sizeof(struct mousedev_client), GFP_KERNEL);
+	if (!client)
+		return -ENOMEM;
+
+	spin_lock_init(&client->packet_lock);
+	client->pos_x = xres / 2;
+	client->pos_y = yres / 2;
+	client->mousedev = mousedev;
+	mousedev_attach_client(mousedev, client);
+
+	error = mousedev->open_device(mousedev);
+	if (error)
+		goto err_free_client;
+
+	file->private_data = client;
+	stream_open(inode, file);
+
+	return 0;
+
+ err_free_client:
+	mousedev_detach_client(mousedev, client);
+	kfree(client);
+	return error;
+}
+
+static void mousedev_packet(struct mousedev_client *client, u8 *ps2_data)
+{
+	struct mousedev_motion *p = &client->packets[client->tail];
+	s8 dx, dy, dz;
+
+	dx = clamp_val(p->dx, -127, 127);
+	p->dx -= dx;
+
+	dy = clamp_val(p->dy, -127, 127);
+	p->dy -= dy;
+
+	ps2_data[0] = BIT(3);
+	ps2_data[0] |= ((dx & BIT(7)) >> 3) | ((dy & BIT(7)) >> 2);
+	ps2_data[0] |= p->buttons & 0x07;
+	ps2_data[1] = dx;
+	ps2_data[2] = dy;
+
+	switch (client->mode) {
+	case MOUSEDEV_EMUL_EXPS:
+		dz = clamp_val(p->dz, -7, 7);
+		p->dz -= dz;
+
+		ps2_data[3] = (dz & 0x0f) | ((p->buttons & 0x18) << 1);
+		client->bufsiz = 4;
+		break;
+
+	case MOUSEDEV_EMUL_IMPS:
+		dz = clamp_val(p->dz, -127, 127);
+		p->dz -= dz;
+
+		ps2_data[0] |= ((p->buttons & 0x10) >> 3) |
+			       ((p->buttons & 0x08) >> 1);
+		ps2_data[3] = dz;
+
+		client->bufsiz = 4;
+		break;
+
+	case MOUSEDEV_EMUL_PS2:
+	default:
+		p->dz = 0;
+
+		ps2_data[0] |= ((p->buttons & 0x10) >> 3) |
+			       ((p->buttons & 0x08) >> 1);
+
+		client->bufsiz = 3;
+		break;
+	}
+
+	if (!p->dx && !p->dy && !p->dz) {
+		if (client->tail == client->head) {
+			client->ready = 0;
+			client->last_buttons = p->buttons;
+		} else
+			client->tail = (client->tail + 1) % PACKET_QUEUE_LEN;
+	}
+}
+
+static void mousedev_generate_response(struct mousedev_client *client,
+					int command)
+{
+	client->ps2[0] = 0xfa; /* ACK */
+
+	switch (command) {
+
+	case 0xeb: /* Poll */
+		mousedev_packet(client, &client->ps2[1]);
+		client->bufsiz++; /* account for leading ACK */
+		break;
+
+	case 0xf2: /* Get ID */
+		switch (client->mode) {
+		case MOUSEDEV_EMUL_PS2:
+			client->ps2[1] = 0;
+			break;
+		case MOUSEDEV_EMUL_IMPS:
+			client->ps2[1] = 3;
+			break;
+		case MOUSEDEV_EMUL_EXPS:
+			client->ps2[1] = 4;
+			break;
+		}
+		client->bufsiz = 2;
+		break;
+
+	case 0xe9: /* Get info */
+		client->ps2[1] = 0x60; client->ps2[2] = 3; client->ps2[3] = 200;
+		client->bufsiz = 4;
+		break;
+
+	case 0xff: /* Reset */
+		client->impsseq = client->imexseq = 0;
+		client->mode = MOUSEDEV_EMUL_PS2;
+		client->ps2[1] = 0xaa; client->ps2[2] = 0x00;
+		client->bufsiz = 3;
+		break;
+
+	default:
+		client->bufsiz = 1;
+		break;
+	}
+	client->buffer = client->bufsiz;
+}
+
+static ssize_t mousedev_write(struct file *file, const char __user *buffer,
+				size_t count, loff_t *ppos)
+{
+	struct mousedev_client *client = file->private_data;
+	unsigned char c;
+	unsigned int i;
+
+	for (i = 0; i < count; i++) {
+
+		if (get_user(c, buffer + i))
+			return -EFAULT;
+
+		spin_lock_irq(&client->packet_lock);
+
+		if (c == mousedev_imex_seq[client->imexseq]) {
+			if (++client->imexseq == MOUSEDEV_SEQ_LEN) {
+				client->imexseq = 0;
+				client->mode = MOUSEDEV_EMUL_EXPS;
+			}
+		} else
+			client->imexseq = 0;
+
+		if (c == mousedev_imps_seq[client->impsseq]) {
+			if (++client->impsseq == MOUSEDEV_SEQ_LEN) {
+				client->impsseq = 0;
+				client->mode = MOUSEDEV_EMUL_IMPS;
+			}
+		} else
+			client->impsseq = 0;
+
+		mousedev_generate_response(client, c);
+
+		spin_unlock_irq(&client->packet_lock);
+		cond_resched();
+	}
+
+	kill_fasync(&client->fasync, SIGIO, POLL_IN);
+	wake_up_interruptible(&client->mousedev->wait);
+
+	return count;
+}
+
+static ssize_t mousedev_read(struct file *file, char __user *buffer,
+			     size_t count, loff_t *ppos)
+{
+	struct mousedev_client *client = file->private_data;
+	struct mousedev *mousedev = client->mousedev;
+	u8 data[sizeof(client->ps2)];
+	int retval = 0;
+
+	if (!client->ready && !client->buffer && mousedev->exist &&
+	    (file->f_flags & O_NONBLOCK))
+		return -EAGAIN;
+
+	retval = wait_event_interruptible(mousedev->wait,
+			!mousedev->exist || client->ready || client->buffer);
+	if (retval)
+		return retval;
+
+	if (!mousedev->exist)
+		return -ENODEV;
+
+	spin_lock_irq(&client->packet_lock);
+
+	if (!client->buffer && client->ready) {
+		mousedev_packet(client, client->ps2);
+		client->buffer = client->bufsiz;
+	}
+
+	if (count > client->buffer)
+		count = client->buffer;
+
+	memcpy(data, client->ps2 + client->bufsiz - client->buffer, count);
+	client->buffer -= count;
+
+	spin_unlock_irq(&client->packet_lock);
+
+	if (copy_to_user(buffer, data, count))
+		return -EFAULT;
+
+	return count;
+}
+
+/* No kernel lock - fine */
+static __poll_t mousedev_poll(struct file *file, poll_table *wait)
+{
+	struct mousedev_client *client = file->private_data;
+	struct mousedev *mousedev = client->mousedev;
+	__poll_t mask;
+
+	poll_wait(file, &mousedev->wait, wait);
+
+	mask = mousedev->exist ? EPOLLOUT | EPOLLWRNORM : EPOLLHUP | EPOLLERR;
+	if (client->ready || client->buffer)
+		mask |= EPOLLIN | EPOLLRDNORM;
+
+	return mask;
+}
+
+static const struct file_operations mousedev_fops = {
+	.owner		= THIS_MODULE,
+	.read		= mousedev_read,
+	.write		= mousedev_write,
+	.poll		= mousedev_poll,
+	.open		= mousedev_open,
+	.release	= mousedev_release,
+	.fasync		= mousedev_fasync,
+	.llseek		= noop_llseek,
+};
+
+/*
+ * Mark device non-existent. This disables writes, ioctls and
+ * prevents new users from opening the device. Already posted
+ * blocking reads will stay, however new ones will fail.
+ */
+static void mousedev_mark_dead(struct mousedev *mousedev)
+{
+	mutex_lock(&mousedev->mutex);
+	mousedev->exist = false;
+	mutex_unlock(&mousedev->mutex);
+}
+
+/*
+ * Wake up users waiting for IO so they can disconnect from
+ * dead device.
+ */
+static void mousedev_hangup(struct mousedev *mousedev)
+{
+	struct mousedev_client *client;
+
+	spin_lock(&mousedev->client_lock);
+	list_for_each_entry(client, &mousedev->client_list, node)
+		kill_fasync(&client->fasync, SIGIO, POLL_HUP);
+	spin_unlock(&mousedev->client_lock);
+
+	wake_up_interruptible(&mousedev->wait);
+}
+
+static void mousedev_cleanup(struct mousedev *mousedev)
+{
+	struct input_handle *handle = &mousedev->handle;
+
+	mousedev_mark_dead(mousedev);
+	mousedev_hangup(mousedev);
+
+	/* mousedev is marked dead so no one else accesses mousedev->open */
+	if (mousedev->open)
+		input_close_device(handle);
+}
+
+static int mousedev_reserve_minor(bool mixdev)
+{
+	int minor;
+
+	if (mixdev) {
+		minor = input_get_new_minor(MOUSEDEV_MIX, 1, false);
+		if (minor < 0)
+			pr_err("failed to reserve mixdev minor: %d\n", minor);
+	} else {
+		minor = input_get_new_minor(MOUSEDEV_MINOR_BASE,
+					    MOUSEDEV_MINORS, true);
+		if (minor < 0)
+			pr_err("failed to reserve new minor: %d\n", minor);
+	}
+
+	return minor;
+}
+
+static struct mousedev *mousedev_create(struct input_dev *dev,
+					struct input_handler *handler,
+					bool mixdev)
+{
+	struct mousedev *mousedev;
+	int minor;
+	int error;
+
+	minor = mousedev_reserve_minor(mixdev);
+	if (minor < 0) {
+		error = minor;
+		goto err_out;
+	}
+
+	mousedev = kzalloc(sizeof(struct mousedev), GFP_KERNEL);
+	if (!mousedev) {
+		error = -ENOMEM;
+		goto err_free_minor;
+	}
+
+	INIT_LIST_HEAD(&mousedev->client_list);
+	INIT_LIST_HEAD(&mousedev->mixdev_node);
+	spin_lock_init(&mousedev->client_lock);
+	mutex_init(&mousedev->mutex);
+	lockdep_set_subclass(&mousedev->mutex,
+			     mixdev ? SINGLE_DEPTH_NESTING : 0);
+	init_waitqueue_head(&mousedev->wait);
+
+	if (mixdev) {
+		dev_set_name(&mousedev->dev, "mice");
+
+		mousedev->open_device = mixdev_open_devices;
+		mousedev->close_device = mixdev_close_devices;
+	} else {
+		int dev_no = minor;
+		/* Normalize device number if it falls into legacy range */
+		if (dev_no < MOUSEDEV_MINOR_BASE + MOUSEDEV_MINORS)
+			dev_no -= MOUSEDEV_MINOR_BASE;
+		dev_set_name(&mousedev->dev, "mouse%d", dev_no);
+
+		mousedev->open_device = mousedev_open_device;
+		mousedev->close_device = mousedev_close_device;
+	}
+
+	mousedev->exist = true;
+	mousedev->handle.dev = input_get_device(dev);
+	mousedev->handle.name = dev_name(&mousedev->dev);
+	mousedev->handle.handler = handler;
+	mousedev->handle.private = mousedev;
+
+	mousedev->dev.class = &input_class;
+	if (dev)
+		mousedev->dev.parent = &dev->dev;
+	mousedev->dev.devt = MKDEV(INPUT_MAJOR, minor);
+	mousedev->dev.release = mousedev_free;
+	device_initialize(&mousedev->dev);
+
+	if (!mixdev) {
+		error = input_register_handle(&mousedev->handle);
+		if (error)
+			goto err_free_mousedev;
+	}
+
+	cdev_init(&mousedev->cdev, &mousedev_fops);
+
+	error = cdev_device_add(&mousedev->cdev, &mousedev->dev);
+	if (error)
+		goto err_cleanup_mousedev;
+
+	return mousedev;
+
+ err_cleanup_mousedev:
+	mousedev_cleanup(mousedev);
+	if (!mixdev)
+		input_unregister_handle(&mousedev->handle);
+ err_free_mousedev:
+	put_device(&mousedev->dev);
+ err_free_minor:
+	input_free_minor(minor);
+ err_out:
+	return ERR_PTR(error);
+}
+
+static void mousedev_destroy(struct mousedev *mousedev)
+{
+	cdev_device_del(&mousedev->cdev, &mousedev->dev);
+	mousedev_cleanup(mousedev);
+	input_free_minor(MINOR(mousedev->dev.devt));
+	if (mousedev != mousedev_mix)
+		input_unregister_handle(&mousedev->handle);
+	put_device(&mousedev->dev);
+}
+
+static int mixdev_add_device(struct mousedev *mousedev)
+{
+	int retval;
+
+	retval = mutex_lock_interruptible(&mousedev_mix->mutex);
+	if (retval)
+		return retval;
+
+	if (mousedev_mix->open) {
+		retval = mousedev_open_device(mousedev);
+		if (retval)
+			goto out;
+
+		mousedev->opened_by_mixdev = true;
+	}
+
+	get_device(&mousedev->dev);
+	list_add_tail(&mousedev->mixdev_node, &mousedev_mix_list);
+
+ out:
+	mutex_unlock(&mousedev_mix->mutex);
+	return retval;
+}
+
+static void mixdev_remove_device(struct mousedev *mousedev)
+{
+	mutex_lock(&mousedev_mix->mutex);
+
+	if (mousedev->opened_by_mixdev) {
+		mousedev->opened_by_mixdev = false;
+		mousedev_close_device(mousedev);
+	}
+
+	list_del_init(&mousedev->mixdev_node);
+	mutex_unlock(&mousedev_mix->mutex);
+
+	put_device(&mousedev->dev);
+}
+
+static int mousedev_connect(struct input_handler *handler,
+			    struct input_dev *dev,
+			    const struct input_device_id *id)
+{
+	struct mousedev *mousedev;
+	int error;
+
+	mousedev = mousedev_create(dev, handler, false);
+	if (IS_ERR(mousedev))
+		return PTR_ERR(mousedev);
+
+	error = mixdev_add_device(mousedev);
+	if (error) {
+		mousedev_destroy(mousedev);
+		return error;
+	}
+
+	return 0;
+}
+
+static void mousedev_disconnect(struct input_handle *handle)
+{
+	struct mousedev *mousedev = handle->private;
+
+	mixdev_remove_device(mousedev);
+	mousedev_destroy(mousedev);
+}
+
+static const struct input_device_id mousedev_ids[] = {
+	{
+		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
+				INPUT_DEVICE_ID_MATCH_KEYBIT |
+				INPUT_DEVICE_ID_MATCH_RELBIT,
+		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) },
+		.keybit = { [BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) },
+		.relbit = { BIT_MASK(REL_X) | BIT_MASK(REL_Y) },
+	},	/* A mouse like device, at least one button,
+		   two relative axes */
+	{
+		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
+				INPUT_DEVICE_ID_MATCH_RELBIT,
+		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) },
+		.relbit = { BIT_MASK(REL_WHEEL) },
+	},	/* A separate scrollwheel */
+	{
+		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
+				INPUT_DEVICE_ID_MATCH_KEYBIT |
+				INPUT_DEVICE_ID_MATCH_ABSBIT,
+		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
+		.keybit = { [BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH) },
+		.absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) },
+	},	/* A tablet like device, at least touch detection,
+		   two absolute axes */
+	{
+		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
+				INPUT_DEVICE_ID_MATCH_KEYBIT |
+				INPUT_DEVICE_ID_MATCH_ABSBIT,
+		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
+		.keybit = { [BIT_WORD(BTN_TOOL_FINGER)] =
+				BIT_MASK(BTN_TOOL_FINGER) },
+		.absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) |
+				BIT_MASK(ABS_PRESSURE) |
+				BIT_MASK(ABS_TOOL_WIDTH) },
+	},	/* A touchpad */
+	{
+		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
+			INPUT_DEVICE_ID_MATCH_KEYBIT |
+			INPUT_DEVICE_ID_MATCH_ABSBIT,
+		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
+		.keybit = { [BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) },
+		.absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) },
+	},	/* Mouse-like device with absolute X and Y but ordinary
+		   clicks, like hp ILO2 High Performance mouse */
+
+	{ },	/* Terminating entry */
+};
+
+MODULE_DEVICE_TABLE(input, mousedev_ids);
+
+static struct input_handler mousedev_handler = {
+	.event		= mousedev_event,
+	.connect	= mousedev_connect,
+	.disconnect	= mousedev_disconnect,
+	.legacy_minors	= true,
+	.minor		= MOUSEDEV_MINOR_BASE,
+	.name		= "mousedev",
+	.id_table	= mousedev_ids,
+};
+
+#ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
+#include <linux/miscdevice.h>
+
+static struct miscdevice psaux_mouse = {
+	.minor	= PSMOUSE_MINOR,
+	.name	= "psaux",
+	.fops	= &mousedev_fops,
+};
+
+static bool psaux_registered;
+
+static void __init mousedev_psaux_register(void)
+{
+	int error;
+
+	error = misc_register(&psaux_mouse);
+	if (error)
+		pr_warn("could not register psaux device, error: %d\n",
+			   error);
+	else
+		psaux_registered = true;
+}
+
+static void __exit mousedev_psaux_unregister(void)
+{
+	if (psaux_registered)
+		misc_deregister(&psaux_mouse);
+}
+#else
+static inline void mousedev_psaux_register(void) { }
+static inline void mousedev_psaux_unregister(void) { }
+#endif
+
+static int __init mousedev_init(void)
+{
+	int error;
+
+	mousedev_mix = mousedev_create(NULL, &mousedev_handler, true);
+	if (IS_ERR(mousedev_mix))
+		return PTR_ERR(mousedev_mix);
+
+	error = input_register_handler(&mousedev_handler);
+	if (error) {
+		mousedev_destroy(mousedev_mix);
+		return error;
+	}
+
+	mousedev_psaux_register();
+
+	pr_info("PS/2 mouse device common for all mice\n");
+
+	return 0;
+}
+
+static void __exit mousedev_exit(void)
+{
+	mousedev_psaux_unregister();
+	input_unregister_handler(&mousedev_handler);
+	mousedev_destroy(mousedev_mix);
+}
+
+module_init(mousedev_init);
+module_exit(mousedev_exit);