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/* drivers/input/keyreset.c
*
* Copyright (C) 2008 Google, Inc.
*
* 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/input.h>
#include <linux/keyreset.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/reboot.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/syscalls.h>
struct keyreset_state {
struct input_handler input_handler;
unsigned long keybit[BITS_TO_LONGS(KEY_CNT)];
unsigned long upbit[BITS_TO_LONGS(KEY_CNT)];
unsigned long key[BITS_TO_LONGS(KEY_CNT)];
spinlock_t lock;
int key_down_target;
int key_down;
int key_up;
int restart_disabled;
int (*reset_fn)(void);
};
int restart_requested;
static void deferred_restart(struct work_struct *dummy)
{
restart_requested = 2;
sys_sync();
restart_requested = 3;
kernel_restart(NULL);
}
static DECLARE_WORK(restart_work, deferred_restart);
static void keyreset_event(struct input_handle *handle, unsigned int type,
unsigned int code, int value)
{
unsigned long flags;
struct keyreset_state *state = handle->private;
if (type != EV_KEY)
return;
if (code >= KEY_MAX)
return;
if (!test_bit(code, state->keybit))
return;
spin_lock_irqsave(&state->lock, flags);
if (!test_bit(code, state->key) == !value)
goto done;
__change_bit(code, state->key);
if (test_bit(code, state->upbit)) {
if (value) {
state->restart_disabled = 1;
state->key_up++;
} else
state->key_up--;
} else {
if (value)
state->key_down++;
else
state->key_down--;
}
if (state->key_down == 0 && state->key_up == 0)
state->restart_disabled = 0;
pr_debug("reset key changed %d %d new state %d-%d-%d\n", code, value,
state->key_down, state->key_up, state->restart_disabled);
if (value && !state->restart_disabled &&
state->key_down == state->key_down_target) {
state->restart_disabled = 1;
if (restart_requested)
panic("keyboard reset failed, %d", restart_requested);
if (state->reset_fn) {
restart_requested = state->reset_fn();
} else {
pr_info("keyboard reset\n");
schedule_work(&restart_work);
restart_requested = 1;
}
}
done:
spin_unlock_irqrestore(&state->lock, flags);
}
static int keyreset_connect(struct input_handler *handler,
struct input_dev *dev,
const struct input_device_id *id)
{
int i;
int ret;
struct input_handle *handle;
struct keyreset_state *state =
container_of(handler, struct keyreset_state, input_handler);
for (i = 0; i < KEY_MAX; i++) {
if (test_bit(i, state->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 = "keyreset";
handle->private = state;
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("using input dev %s for key reset\n", dev->name);
return 0;
err_input_open_device:
input_unregister_handle(handle);
err_input_register_handle:
kfree(handle);
return ret;
}
static void keyreset_disconnect(struct input_handle *handle)
{
input_close_device(handle);
input_unregister_handle(handle);
kfree(handle);
}
static const struct input_device_id keyreset_ids[] = {
{
.flags = INPUT_DEVICE_ID_MATCH_EVBIT,
.evbit = { BIT_MASK(EV_KEY) },
},
{ },
};
MODULE_DEVICE_TABLE(input, keyreset_ids);
static int keyreset_probe(struct platform_device *pdev)
{
int ret;
int key, *keyp;
struct keyreset_state *state;
struct keyreset_platform_data *pdata = pdev->dev.platform_data;
if (!pdata)
return -EINVAL;
state = kzalloc(sizeof(*state), GFP_KERNEL);
if (!state)
return -ENOMEM;
spin_lock_init(&state->lock);
keyp = pdata->keys_down;
while ((key = *keyp++)) {
if (key >= KEY_MAX)
continue;
state->key_down_target++;
__set_bit(key, state->keybit);
}
if (pdata->keys_up) {
keyp = pdata->keys_up;
while ((key = *keyp++)) {
if (key >= KEY_MAX)
continue;
__set_bit(key, state->keybit);
__set_bit(key, state->upbit);
}
}
if (pdata->reset_fn)
state->reset_fn = pdata->reset_fn;
state->input_handler.event = keyreset_event;
state->input_handler.connect = keyreset_connect;
state->input_handler.disconnect = keyreset_disconnect;
state->input_handler.name = KEYRESET_NAME;
state->input_handler.id_table = keyreset_ids;
ret = input_register_handler(&state->input_handler);
if (ret) {
kfree(state);
return ret;
}
platform_set_drvdata(pdev, state);
return 0;
}
int keyreset_remove(struct platform_device *pdev)
{
struct keyreset_state *state = platform_get_drvdata(pdev);
input_unregister_handler(&state->input_handler);
kfree(state);
return 0;
}
struct platform_driver keyreset_driver = {
.driver.name = KEYRESET_NAME,
.probe = keyreset_probe,
.remove = keyreset_remove,
};
static int __init keyreset_init(void)
{
return platform_driver_register(&keyreset_driver);
}
static void __exit keyreset_exit(void)
{
return platform_driver_unregister(&keyreset_driver);
}
module_init(keyreset_init);
module_exit(keyreset_exit);
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