From 2494f399ad1b920667dc59c58612f8ede34641d3 Mon Sep 17 00:00:00 2001 From: Mike Lockwood Date: Mon, 15 Dec 2008 14:51:56 -0500 Subject: input: keychord: Add keychord driver This driver allows userspace to receive notification when client specified key combinations are pressed. The client opens /dev/keychord and writes a list of keychords for the driver to monitor. The client then reads or polls /dev/keychord for notifications. A client specified ID for the keychord is returned from read() when a keychord press is detected. Signed-off-by: Mike Lockwood keychord: fix to build without CONFIG_PREEMPT Change-Id: I911f13aeda4224b6fa57863bc7e8972fec8837fb --- drivers/input/misc/Kconfig | 11 ++ drivers/input/misc/Makefile | 1 + drivers/input/misc/keychord.c | 387 ++++++++++++++++++++++++++++++++++++++++++ include/linux/keychord.h | 52 ++++++ 4 files changed, 451 insertions(+) create mode 100644 drivers/input/misc/keychord.c create mode 100644 include/linux/keychord.h diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig index efb0ca8..625413c 100644 --- a/drivers/input/misc/Kconfig +++ b/drivers/input/misc/Kconfig @@ -355,6 +355,17 @@ 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 diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile index 6a1e5e2..576b52a 100644 --- a/drivers/input/misc/Makefile +++ b/drivers/input/misc/Makefile @@ -39,6 +39,7 @@ 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 diff --git a/drivers/input/misc/keychord.c b/drivers/input/misc/keychord.c new file mode 100644 index 0000000..3ffab6d --- /dev/null +++ b/drivers/input/misc/keychord.c @@ -0,0 +1,387 @@ +/* + * drivers/input/misc/keychord.c + * + * Copyright (C) 2008 Google, Inc. + * Author: Mike Lockwood + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include + +#define KEYCHORD_NAME "keychord" +#define BUFFER_SIZE 16 + +MODULE_AUTHOR("Mike Lockwood "); +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); diff --git a/include/linux/keychord.h b/include/linux/keychord.h new file mode 100644 index 0000000..856a585 --- /dev/null +++ b/include/linux/keychord.h @@ -0,0 +1,52 @@ +/* + * Key chord input driver + * + * Copyright (C) 2008 Google, Inc. + * Author: Mike Lockwood + * + * 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 + +#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 /* __LINUX_KEYCHORD_H_ */ -- cgit v1.1