Daniel Rosenberg | e6b39a8 | 2014-05-07 16:52:10 -0700 | [diff] [blame] | 1 | /* drivers/input/keycombo.c |
| 2 | * |
| 3 | * Copyright (C) 2014 Google, Inc. |
| 4 | * |
| 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. |
| 8 | * |
| 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. |
| 13 | * |
| 14 | */ |
| 15 | |
| 16 | #include <linux/input.h> |
| 17 | #include <linux/keycombo.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 | |
| 24 | struct keycombo_state { |
| 25 | struct input_handler input_handler; |
| 26 | unsigned long keybit[BITS_TO_LONGS(KEY_CNT)]; |
| 27 | unsigned long upbit[BITS_TO_LONGS(KEY_CNT)]; |
| 28 | unsigned long key[BITS_TO_LONGS(KEY_CNT)]; |
| 29 | spinlock_t lock; |
| 30 | struct workqueue_struct *wq; |
| 31 | int key_down_target; |
| 32 | int key_down; |
| 33 | int key_up; |
| 34 | struct delayed_work key_down_work; |
| 35 | int delay; |
| 36 | struct work_struct key_up_work; |
| 37 | void (*key_up_fn)(void *); |
| 38 | void (*key_down_fn)(void *); |
| 39 | void *priv; |
| 40 | int key_is_down; |
| 41 | struct wakeup_source combo_held_wake_source; |
| 42 | struct wakeup_source combo_up_wake_source; |
| 43 | }; |
| 44 | |
| 45 | static void do_key_down(struct work_struct *work) |
| 46 | { |
| 47 | struct delayed_work *dwork = container_of(work, struct delayed_work, |
| 48 | work); |
| 49 | struct keycombo_state *state = container_of(dwork, |
| 50 | struct keycombo_state, key_down_work); |
| 51 | if (state->key_down_fn) |
| 52 | state->key_down_fn(state->priv); |
| 53 | } |
| 54 | |
| 55 | static void do_key_up(struct work_struct *work) |
| 56 | { |
| 57 | struct keycombo_state *state = container_of(work, struct keycombo_state, |
| 58 | key_up_work); |
| 59 | if (state->key_up_fn) |
| 60 | state->key_up_fn(state->priv); |
| 61 | __pm_relax(&state->combo_up_wake_source); |
| 62 | } |
| 63 | |
| 64 | static void keycombo_event(struct input_handle *handle, unsigned int type, |
| 65 | unsigned int code, int value) |
| 66 | { |
| 67 | unsigned long flags; |
| 68 | struct keycombo_state *state = handle->private; |
| 69 | |
| 70 | if (type != EV_KEY) |
| 71 | return; |
| 72 | |
| 73 | if (code >= KEY_MAX) |
| 74 | return; |
| 75 | |
| 76 | if (!test_bit(code, state->keybit)) |
| 77 | return; |
| 78 | |
| 79 | spin_lock_irqsave(&state->lock, flags); |
| 80 | if (!test_bit(code, state->key) == !value) |
| 81 | goto done; |
| 82 | __change_bit(code, state->key); |
| 83 | if (test_bit(code, state->upbit)) { |
| 84 | if (value) |
| 85 | state->key_up++; |
| 86 | else |
| 87 | state->key_up--; |
| 88 | } else { |
| 89 | if (value) |
| 90 | state->key_down++; |
| 91 | else |
| 92 | state->key_down--; |
| 93 | } |
| 94 | if (state->key_down == state->key_down_target && state->key_up == 0) { |
| 95 | __pm_stay_awake(&state->combo_held_wake_source); |
| 96 | state->key_is_down = 1; |
| 97 | if (queue_delayed_work(state->wq, &state->key_down_work, |
| 98 | state->delay)) |
| 99 | pr_debug("Key down work already queued!"); |
| 100 | } else if (state->key_is_down) { |
| 101 | if (!cancel_delayed_work(&state->key_down_work)) { |
| 102 | __pm_stay_awake(&state->combo_up_wake_source); |
| 103 | queue_work(state->wq, &state->key_up_work); |
| 104 | } |
| 105 | __pm_relax(&state->combo_held_wake_source); |
| 106 | state->key_is_down = 0; |
| 107 | } |
| 108 | done: |
| 109 | spin_unlock_irqrestore(&state->lock, flags); |
| 110 | } |
| 111 | |
| 112 | static int keycombo_connect(struct input_handler *handler, |
| 113 | struct input_dev *dev, |
| 114 | const struct input_device_id *id) |
| 115 | { |
| 116 | int i; |
| 117 | int ret; |
| 118 | struct input_handle *handle; |
| 119 | struct keycombo_state *state = |
| 120 | container_of(handler, struct keycombo_state, input_handler); |
| 121 | for (i = 0; i < KEY_MAX; i++) { |
| 122 | if (test_bit(i, state->keybit) && test_bit(i, dev->keybit)) |
| 123 | break; |
| 124 | } |
| 125 | if (i == KEY_MAX) |
| 126 | return -ENODEV; |
| 127 | |
| 128 | handle = kzalloc(sizeof(*handle), GFP_KERNEL); |
| 129 | if (!handle) |
| 130 | return -ENOMEM; |
| 131 | |
| 132 | handle->dev = dev; |
| 133 | handle->handler = handler; |
| 134 | handle->name = KEYCOMBO_NAME; |
| 135 | handle->private = state; |
| 136 | |
| 137 | ret = input_register_handle(handle); |
| 138 | if (ret) |
| 139 | goto err_input_register_handle; |
| 140 | |
| 141 | ret = input_open_device(handle); |
| 142 | if (ret) |
| 143 | goto err_input_open_device; |
| 144 | |
| 145 | return 0; |
| 146 | |
| 147 | err_input_open_device: |
| 148 | input_unregister_handle(handle); |
| 149 | err_input_register_handle: |
| 150 | kfree(handle); |
| 151 | return ret; |
| 152 | } |
| 153 | |
| 154 | static void keycombo_disconnect(struct input_handle *handle) |
| 155 | { |
| 156 | input_close_device(handle); |
| 157 | input_unregister_handle(handle); |
| 158 | kfree(handle); |
| 159 | } |
| 160 | |
| 161 | static const struct input_device_id keycombo_ids[] = { |
| 162 | { |
| 163 | .flags = INPUT_DEVICE_ID_MATCH_EVBIT, |
| 164 | .evbit = { BIT_MASK(EV_KEY) }, |
| 165 | }, |
| 166 | { }, |
| 167 | }; |
| 168 | MODULE_DEVICE_TABLE(input, keycombo_ids); |
| 169 | |
| 170 | static int keycombo_probe(struct platform_device *pdev) |
| 171 | { |
| 172 | int ret; |
| 173 | int key, *keyp; |
| 174 | struct keycombo_state *state; |
| 175 | struct keycombo_platform_data *pdata = pdev->dev.platform_data; |
| 176 | |
| 177 | if (!pdata) |
| 178 | return -EINVAL; |
| 179 | |
| 180 | state = kzalloc(sizeof(*state), GFP_KERNEL); |
| 181 | if (!state) |
| 182 | return -ENOMEM; |
| 183 | |
| 184 | spin_lock_init(&state->lock); |
| 185 | keyp = pdata->keys_down; |
| 186 | while ((key = *keyp++)) { |
| 187 | if (key >= KEY_MAX) |
| 188 | continue; |
| 189 | state->key_down_target++; |
| 190 | __set_bit(key, state->keybit); |
| 191 | } |
| 192 | if (pdata->keys_up) { |
| 193 | keyp = pdata->keys_up; |
| 194 | while ((key = *keyp++)) { |
| 195 | if (key >= KEY_MAX) |
| 196 | continue; |
| 197 | __set_bit(key, state->keybit); |
| 198 | __set_bit(key, state->upbit); |
| 199 | } |
| 200 | } |
| 201 | |
| 202 | state->wq = alloc_ordered_workqueue("keycombo", 0); |
| 203 | if (!state->wq) |
| 204 | return -ENOMEM; |
| 205 | |
| 206 | state->priv = pdata->priv; |
| 207 | |
| 208 | if (pdata->key_down_fn) |
| 209 | state->key_down_fn = pdata->key_down_fn; |
| 210 | INIT_DELAYED_WORK(&state->key_down_work, do_key_down); |
| 211 | |
| 212 | if (pdata->key_up_fn) |
| 213 | state->key_up_fn = pdata->key_up_fn; |
| 214 | INIT_WORK(&state->key_up_work, do_key_up); |
| 215 | |
| 216 | wakeup_source_init(&state->combo_held_wake_source, "key combo"); |
| 217 | wakeup_source_init(&state->combo_up_wake_source, "key combo up"); |
| 218 | state->delay = msecs_to_jiffies(pdata->key_down_delay); |
| 219 | |
| 220 | state->input_handler.event = keycombo_event; |
| 221 | state->input_handler.connect = keycombo_connect; |
| 222 | state->input_handler.disconnect = keycombo_disconnect; |
| 223 | state->input_handler.name = KEYCOMBO_NAME; |
| 224 | state->input_handler.id_table = keycombo_ids; |
| 225 | ret = input_register_handler(&state->input_handler); |
| 226 | if (ret) { |
| 227 | kfree(state); |
| 228 | return ret; |
| 229 | } |
| 230 | platform_set_drvdata(pdev, state); |
| 231 | return 0; |
| 232 | } |
| 233 | |
| 234 | int keycombo_remove(struct platform_device *pdev) |
| 235 | { |
| 236 | struct keycombo_state *state = platform_get_drvdata(pdev); |
| 237 | input_unregister_handler(&state->input_handler); |
| 238 | destroy_workqueue(state->wq); |
| 239 | kfree(state); |
| 240 | return 0; |
| 241 | } |
| 242 | |
| 243 | |
| 244 | struct platform_driver keycombo_driver = { |
| 245 | .driver.name = KEYCOMBO_NAME, |
| 246 | .probe = keycombo_probe, |
| 247 | .remove = keycombo_remove, |
| 248 | }; |
| 249 | |
| 250 | static int __init keycombo_init(void) |
| 251 | { |
| 252 | return platform_driver_register(&keycombo_driver); |
| 253 | } |
| 254 | |
| 255 | static void __exit keycombo_exit(void) |
| 256 | { |
| 257 | return platform_driver_unregister(&keycombo_driver); |
| 258 | } |
| 259 | |
| 260 | module_init(keycombo_init); |
| 261 | module_exit(keycombo_exit); |