--- /dev/null
+/*
+ * drivers/input/misc/keychord.c
+ *
+ * Copyright (C) 2008 Google, Inc.
+ * Author: Mike Lockwood <lockwood@android.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+*/
+
+#include <linux/poll.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/keychord.h>
+#include <linux/sched.h>
+
+#define KEYCHORD_NAME "keychord"
+#define BUFFER_SIZE 16
+
+MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
+MODULE_DESCRIPTION("Key chord input driver");
+MODULE_SUPPORTED_DEVICE("keychord");
+MODULE_LICENSE("GPL");
+
+#define NEXT_KEYCHORD(kc) ((struct input_keychord *) \
+ ((char *)kc + sizeof(struct input_keychord) + \
+ kc->count * sizeof(kc->keycodes[0])))
+
+struct keychord_device {
+ struct input_handler input_handler;
+ int registered;
+
+ /* list of keychords to monitor */
+ struct input_keychord *keychords;
+ int keychord_count;
+
+ /* bitmask of keys contained in our keychords */
+ unsigned long keybit[BITS_TO_LONGS(KEY_CNT)];
+ /* current state of the keys */
+ unsigned long keystate[BITS_TO_LONGS(KEY_CNT)];
+ /* number of keys that are currently pressed */
+ int key_down;
+
+ /* second input_device_id is needed for null termination */
+ struct input_device_id device_ids[2];
+
+ spinlock_t lock;
+ wait_queue_head_t waitq;
+ unsigned char head;
+ unsigned char tail;
+ __u16 buff[BUFFER_SIZE];
+};
+
+static int check_keychord(struct keychord_device *kdev,
+ struct input_keychord *keychord)
+{
+ int i;
+
+ if (keychord->count != kdev->key_down)
+ return 0;
+
+ for (i = 0; i < keychord->count; i++) {
+ if (!test_bit(keychord->keycodes[i], kdev->keystate))
+ return 0;
+ }
+
+ /* we have a match */
+ return 1;
+}
+
+static void keychord_event(struct input_handle *handle, unsigned int type,
+ unsigned int code, int value)
+{
+ struct keychord_device *kdev = handle->private;
+ struct input_keychord *keychord;
+ unsigned long flags;
+ int i, got_chord = 0;
+
+ if (type != EV_KEY || code >= KEY_MAX)
+ return;
+
+ spin_lock_irqsave(&kdev->lock, flags);
+ /* do nothing if key state did not change */
+ if (!test_bit(code, kdev->keystate) == !value)
+ goto done;
+ __change_bit(code, kdev->keystate);
+ if (value)
+ kdev->key_down++;
+ else
+ kdev->key_down--;
+
+ /* don't notify on key up */
+ if (!value)
+ goto done;
+ /* ignore this event if it is not one of the keys we are monitoring */
+ if (!test_bit(code, kdev->keybit))
+ goto done;
+
+ keychord = kdev->keychords;
+ if (!keychord)
+ goto done;
+
+ /* check to see if the keyboard state matches any keychords */
+ for (i = 0; i < kdev->keychord_count; i++) {
+ if (check_keychord(kdev, keychord)) {
+ kdev->buff[kdev->head] = keychord->id;
+ kdev->head = (kdev->head + 1) % BUFFER_SIZE;
+ got_chord = 1;
+ break;
+ }
+ /* skip to next keychord */
+ keychord = NEXT_KEYCHORD(keychord);
+ }
+
+done:
+ spin_unlock_irqrestore(&kdev->lock, flags);
+
+ if (got_chord)
+ wake_up_interruptible(&kdev->waitq);
+}
+
+static int keychord_connect(struct input_handler *handler,
+ struct input_dev *dev,
+ const struct input_device_id *id)
+{
+ int i, ret;
+ struct input_handle *handle;
+ struct keychord_device *kdev =
+ container_of(handler, struct keychord_device, input_handler);
+
+ /*
+ * ignore this input device if it does not contain any keycodes
+ * that we are monitoring
+ */
+ for (i = 0; i < KEY_MAX; i++) {
+ if (test_bit(i, kdev->keybit) && test_bit(i, dev->keybit))
+ break;
+ }
+ if (i == KEY_MAX)
+ return -ENODEV;
+
+ handle = kzalloc(sizeof(*handle), GFP_KERNEL);
+ if (!handle)
+ return -ENOMEM;
+
+ handle->dev = dev;
+ handle->handler = handler;
+ handle->name = KEYCHORD_NAME;
+ handle->private = kdev;
+
+ ret = input_register_handle(handle);
+ if (ret)
+ goto err_input_register_handle;
+
+ ret = input_open_device(handle);
+ if (ret)
+ goto err_input_open_device;
+
+ pr_info("keychord: using input dev %s for fevent\n", dev->name);
+
+ return 0;
+
+err_input_open_device:
+ input_unregister_handle(handle);
+err_input_register_handle:
+ kfree(handle);
+ return ret;
+}
+
+static void keychord_disconnect(struct input_handle *handle)
+{
+ input_close_device(handle);
+ input_unregister_handle(handle);
+ kfree(handle);
+}
+
+/*
+ * keychord_read is used to read keychord events from the driver
+ */
+static ssize_t keychord_read(struct file *file, char __user *buffer,
+ size_t count, loff_t *ppos)
+{
+ struct keychord_device *kdev = file->private_data;
+ __u16 id;
+ int retval;
+ unsigned long flags;
+
+ if (count < sizeof(id))
+ return -EINVAL;
+ count = sizeof(id);
+
+ if (kdev->head == kdev->tail && (file->f_flags & O_NONBLOCK))
+ return -EAGAIN;
+
+ retval = wait_event_interruptible(kdev->waitq,
+ kdev->head != kdev->tail);
+ if (retval)
+ return retval;
+
+ spin_lock_irqsave(&kdev->lock, flags);
+ /* pop a keychord ID off the queue */
+ id = kdev->buff[kdev->tail];
+ kdev->tail = (kdev->tail + 1) % BUFFER_SIZE;
+ spin_unlock_irqrestore(&kdev->lock, flags);
+
+ if (copy_to_user(buffer, &id, count))
+ return -EFAULT;
+
+ return count;
+}
+
+/*
+ * keychord_write is used to configure the driver
+ */
+static ssize_t keychord_write(struct file *file, const char __user *buffer,
+ size_t count, loff_t *ppos)
+{
+ struct keychord_device *kdev = file->private_data;
+ struct input_keychord *keychords = 0;
+ struct input_keychord *keychord, *next, *end;
+ int ret, i, key;
+ unsigned long flags;
+
+ if (count < sizeof(struct input_keychord))
+ return -EINVAL;
+ keychords = kzalloc(count, GFP_KERNEL);
+ if (!keychords)
+ return -ENOMEM;
+
+ /* read list of keychords from userspace */
+ if (copy_from_user(keychords, buffer, count)) {
+ kfree(keychords);
+ return -EFAULT;
+ }
+
+ /* unregister handler before changing configuration */
+ if (kdev->registered) {
+ input_unregister_handler(&kdev->input_handler);
+ kdev->registered = 0;
+ }
+
+ spin_lock_irqsave(&kdev->lock, flags);
+ /* clear any existing configuration */
+ kfree(kdev->keychords);
+ kdev->keychords = 0;
+ kdev->keychord_count = 0;
+ kdev->key_down = 0;
+ memset(kdev->keybit, 0, sizeof(kdev->keybit));
+ memset(kdev->keystate, 0, sizeof(kdev->keystate));
+ kdev->head = kdev->tail = 0;
+
+ keychord = keychords;
+ end = (struct input_keychord *)((char *)keychord + count);
+
+ while (keychord < end) {
+ next = NEXT_KEYCHORD(keychord);
+ if (keychord->count <= 0 || next > end) {
+ pr_err("keychord: invalid keycode count %d\n",
+ keychord->count);
+ goto err_unlock_return;
+ }
+ if (keychord->version != KEYCHORD_VERSION) {
+ pr_err("keychord: unsupported version %d\n",
+ keychord->version);
+ goto err_unlock_return;
+ }
+
+ /* keep track of the keys we are monitoring in keybit */
+ for (i = 0; i < keychord->count; i++) {
+ key = keychord->keycodes[i];
+ if (key < 0 || key >= KEY_CNT) {
+ pr_err("keychord: keycode %d out of range\n",
+ key);
+ goto err_unlock_return;
+ }
+ __set_bit(key, kdev->keybit);
+ }
+
+ kdev->keychord_count++;
+ keychord = next;
+ }
+
+ kdev->keychords = keychords;
+ spin_unlock_irqrestore(&kdev->lock, flags);
+
+ ret = input_register_handler(&kdev->input_handler);
+ if (ret) {
+ kfree(keychords);
+ kdev->keychords = 0;
+ return ret;
+ }
+ kdev->registered = 1;
+
+ return count;
+
+err_unlock_return:
+ spin_unlock_irqrestore(&kdev->lock, flags);
+ kfree(keychords);
+ return -EINVAL;
+}
+
+static unsigned int keychord_poll(struct file *file, poll_table *wait)
+{
+ struct keychord_device *kdev = file->private_data;
+
+ poll_wait(file, &kdev->waitq, wait);
+
+ if (kdev->head != kdev->tail)
+ return POLLIN | POLLRDNORM;
+
+ return 0;
+}
+
+static int keychord_open(struct inode *inode, struct file *file)
+{
+ struct keychord_device *kdev;
+
+ kdev = kzalloc(sizeof(struct keychord_device), GFP_KERNEL);
+ if (!kdev)
+ return -ENOMEM;
+
+ spin_lock_init(&kdev->lock);
+ init_waitqueue_head(&kdev->waitq);
+
+ kdev->input_handler.event = keychord_event;
+ kdev->input_handler.connect = keychord_connect;
+ kdev->input_handler.disconnect = keychord_disconnect;
+ kdev->input_handler.name = KEYCHORD_NAME;
+ kdev->input_handler.id_table = kdev->device_ids;
+
+ kdev->device_ids[0].flags = INPUT_DEVICE_ID_MATCH_EVBIT;
+ __set_bit(EV_KEY, kdev->device_ids[0].evbit);
+
+ file->private_data = kdev;
+
+ return 0;
+}
+
+static int keychord_release(struct inode *inode, struct file *file)
+{
+ struct keychord_device *kdev = file->private_data;
+
+ if (kdev->registered)
+ input_unregister_handler(&kdev->input_handler);
+ kfree(kdev);
+
+ return 0;
+}
+
+static const struct file_operations keychord_fops = {
+ .owner = THIS_MODULE,
+ .open = keychord_open,
+ .release = keychord_release,
+ .read = keychord_read,
+ .write = keychord_write,
+ .poll = keychord_poll,
+};
+
+static struct miscdevice keychord_misc = {
+ .fops = &keychord_fops,
+ .name = KEYCHORD_NAME,
+ .minor = MISC_DYNAMIC_MINOR,
+};
+
+static int __init keychord_init(void)
+{
+ return misc_register(&keychord_misc);
+}
+
+static void __exit keychord_exit(void)
+{
+ misc_deregister(&keychord_misc);
+}
+
+module_init(keychord_init);
+module_exit(keychord_exit);
projects / GitHub / exynos8895 / android_kernel_samsung_universal8895.git / commitdiff