v4.19.13 snapshot.
diff --git a/drivers/input/mousedev.c b/drivers/input/mousedev.c
new file mode 100644
index 0000000..412fa71
--- /dev/null
+++ b/drivers/input/mousedev.c
@@ -0,0 +1,1128 @@
+/*
+ * 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 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;
+ nonseekable_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);