1 /* drivers/input/keyreset.c
3 * Copyright (C) 2008 Google, Inc.
5 * This software is licensed under the terms of the GNU General Public
6 * License version 2, as published by the Free Software Foundation, and
7 * may be copied, distributed, and modified under those terms.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
16 #include <linux/input.h>
17 #include <linux/keyreset.h>
18 #include <linux/module.h>
19 #include <linux/platform_device.h>
20 #include <linux/reboot.h>
21 #include <linux/sched.h>
22 #include <linux/slab.h>
23 #include <linux/syscalls.h>
26 struct keyreset_state {
27 struct input_handler input_handler;
28 unsigned long keybit[BITS_TO_LONGS(KEY_CNT)];
29 unsigned long upbit[BITS_TO_LONGS(KEY_CNT)];
30 unsigned long key[BITS_TO_LONGS(KEY_CNT)];
36 int (*reset_fn)(void);
39 int restart_requested;
40 static void deferred_restart(struct work_struct *dummy)
42 restart_requested = 2;
44 restart_requested = 3;
47 static DECLARE_WORK(restart_work, deferred_restart);
49 static void keyreset_event(struct input_handle *handle, unsigned int type,
50 unsigned int code, int value)
53 struct keyreset_state *state = handle->private;
61 if (!test_bit(code, state->keybit))
64 spin_lock_irqsave(&state->lock, flags);
65 if (!test_bit(code, state->key) == !value)
67 __change_bit(code, state->key);
68 if (test_bit(code, state->upbit)) {
70 state->restart_disabled = 1;
80 if (state->key_down == 0 && state->key_up == 0)
81 state->restart_disabled = 0;
83 pr_debug("reset key changed %d %d new state %d-%d-%d\n", code, value,
84 state->key_down, state->key_up, state->restart_disabled);
86 if (value && !state->restart_disabled &&
87 state->key_down == state->key_down_target) {
88 state->restart_disabled = 1;
89 if (restart_requested)
90 panic("keyboard reset failed, %d", restart_requested);
91 if (state->reset_fn) {
92 restart_requested = state->reset_fn();
94 pr_info("keyboard reset\n");
95 schedule_work(&restart_work);
96 restart_requested = 1;
100 spin_unlock_irqrestore(&state->lock, flags);
103 static int keyreset_connect(struct input_handler *handler,
104 struct input_dev *dev,
105 const struct input_device_id *id)
109 struct input_handle *handle;
110 struct keyreset_state *state =
111 container_of(handler, struct keyreset_state, input_handler);
113 for (i = 0; i < KEY_MAX; i++) {
114 if (test_bit(i, state->keybit) && test_bit(i, dev->keybit))
120 handle = kzalloc(sizeof(*handle), GFP_KERNEL);
125 handle->handler = handler;
126 handle->name = "keyreset";
127 handle->private = state;
129 ret = input_register_handle(handle);
131 goto err_input_register_handle;
133 ret = input_open_device(handle);
135 goto err_input_open_device;
137 pr_info("using input dev %s for key reset\n", dev->name);
141 err_input_open_device:
142 input_unregister_handle(handle);
143 err_input_register_handle:
148 static void keyreset_disconnect(struct input_handle *handle)
150 input_close_device(handle);
151 input_unregister_handle(handle);
155 static const struct input_device_id keyreset_ids[] = {
157 .flags = INPUT_DEVICE_ID_MATCH_EVBIT,
158 .evbit = { BIT_MASK(EV_KEY) },
162 MODULE_DEVICE_TABLE(input, keyreset_ids);
164 static int keyreset_probe(struct platform_device *pdev)
168 struct keyreset_state *state;
169 struct keyreset_platform_data *pdata = pdev->dev.platform_data;
174 state = kzalloc(sizeof(*state), GFP_KERNEL);
178 spin_lock_init(&state->lock);
179 keyp = pdata->keys_down;
180 while ((key = *keyp++)) {
183 state->key_down_target++;
184 __set_bit(key, state->keybit);
186 if (pdata->keys_up) {
187 keyp = pdata->keys_up;
188 while ((key = *keyp++)) {
191 __set_bit(key, state->keybit);
192 __set_bit(key, state->upbit);
197 state->reset_fn = pdata->reset_fn;
199 state->input_handler.event = keyreset_event;
200 state->input_handler.connect = keyreset_connect;
201 state->input_handler.disconnect = keyreset_disconnect;
202 state->input_handler.name = KEYRESET_NAME;
203 state->input_handler.id_table = keyreset_ids;
204 ret = input_register_handler(&state->input_handler);
209 platform_set_drvdata(pdev, state);
213 int keyreset_remove(struct platform_device *pdev)
215 struct keyreset_state *state = platform_get_drvdata(pdev);
216 input_unregister_handler(&state->input_handler);
222 struct platform_driver keyreset_driver = {
223 .driver.name = KEYRESET_NAME,
224 .probe = keyreset_probe,
225 .remove = keyreset_remove,
228 static int __init keyreset_init(void)
230 return platform_driver_register(&keyreset_driver);
233 static void __exit keyreset_exit(void)
235 return platform_driver_unregister(&keyreset_driver);
238 module_init(keyreset_init);
239 module_exit(keyreset_exit);