ANDROID: input: keychord: Add keychord driver (08a0437b) · Commits · e / devices / android_kernel_oneplus_sm8150

drivers/input/misc/Kconfig

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		@@ -367,6 +367,17 @@ config INPUT_ATI_REMOTE2
		To compile this driver as a module, choose M here: the module will be
		called ati_remote2.

		config INPUT_KEYCHORD
		tristate "Key chord input driver support"
		help
		Say Y here if you want to enable the key chord driver
		accessible at /dev/keychord. This driver can be used
		for receiving notifications when client specified key
		combinations are pressed.

		To compile this driver as a module, choose M here: the
		module will be called keychord.

		config INPUT_KEYSPAN_REMOTE
		tristate "Keyspan DMR USB remote control"
		depends on USB_ARCH_HAS_HCD

drivers/input/misc/Makefile

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Original line number	Diff line number	Diff line
		@@ -43,6 +43,7 @@ obj-$(CONFIG_INPUT_HISI_POWERKEY) += hisi_powerkey.o
		obj-$(CONFIG_HP_SDC_RTC) += hp_sdc_rtc.o
		obj-$(CONFIG_INPUT_IMS_PCU) += ims-pcu.o
		obj-$(CONFIG_INPUT_IXP4XX_BEEPER) += ixp4xx-beeper.o
		obj-$(CONFIG_INPUT_KEYCHORD) += keychord.o
		obj-$(CONFIG_INPUT_KEYSPAN_REMOTE) += keyspan_remote.o
		obj-$(CONFIG_INPUT_KXTJ9) += kxtj9.o
		obj-$(CONFIG_INPUT_M68K_BEEP) += m68kspkr.o

drivers/input/misc/keychord.c

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		/*
		* 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);

include/linux/keychord.h

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Original line number	Diff line number	Diff line
		/*
		* Key chord input driver
		*
		* 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.
		*
		*/

		#ifndef __LINUX_KEYCHORD_H_
		#define __LINUX_KEYCHORD_H_

		#include <uapi/linux/keychord.h>

		#endif /* __LINUX_KEYCHORD_H_ */

include/uapi/linux/keychord.h

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		/*
		* Key chord input driver
		*
		* 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.
		*
		*/

		#ifndef _UAPI_LINUX_KEYCHORD_H_
		#define _UAPI_LINUX_KEYCHORD_H_

		#include <linux/input.h>

		#define KEYCHORD_VERSION 1

		/*
		* One or more input_keychord structs are written to /dev/keychord
		* at once to specify the list of keychords to monitor.
		* Reading /dev/keychord returns the id of a keychord when the
		* keychord combination is pressed. A keychord is signalled when
		* all of the keys in the keycode list are in the pressed state.
		* The order in which the keys are pressed does not matter.
		* The keychord will not be signalled if keys not in the keycode
		* list are pressed.
		* Keychords will not be signalled on key release events.
		*/
		struct input_keychord {
		/* should be KEYCHORD_VERSION */
		__u16 version;
		/*
		* client specified ID, returned from read()
		* when this keychord is pressed.
		*/
		__u16 id;

		/* number of keycodes in this keychord */
		__u16 count;

		/* variable length array of keycodes */
		__u16 keycodes[];
		};

		#endif /* _UAPI_LINUX_KEYCHORD_H_ */