net/rfkill/rfkill-input.c

   1 /*
   2  * Input layer to RF Kill interface connector
   3  *
   4  * Copyright (c) 2007 Dmitry Torokhov
   5  */
   6
   7 /*
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License version 2 as published
  10  * by the Free Software Foundation.
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/input.h>
  15 #include <linux/slab.h>
  16 #include <linux/workqueue.h>
  17 #include <linux/init.h>
  18 #include <linux/rfkill.h>
  19 #include <linux/sched.h>
  20
  21 #include "rfkill-input.h"
  22
  23 MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
  24 MODULE_DESCRIPTION("Input layer to RF switch connector");
  25 MODULE_LICENSE("GPL");
  26
  27 enum rfkill_input_master_mode {
  28         RFKILL_INPUT_MASTER_DONOTHING = 0,
  29         RFKILL_INPUT_MASTER_RESTORE = 1,
  30         RFKILL_INPUT_MASTER_UNBLOCKALL = 2,
  31         RFKILL_INPUT_MASTER_MAX,        /* marker */
  32 };
  33
  34 /* Delay (in ms) between consecutive switch ops */
  35 #define RFKILL_OPS_DELAY 200
  36
  37 static enum rfkill_input_master_mode rfkill_master_switch_mode =
  38                                         RFKILL_INPUT_MASTER_UNBLOCKALL;
  39 module_param_named(master_switch_mode, rfkill_master_switch_mode, uint, 0);
  40 MODULE_PARM_DESC(master_switch_mode,
  41         "SW_RFKILL_ALL ON should: 0=do nothing; 1=restore; 2=unblock all");
  42
  43 enum rfkill_global_sched_op {
  44         RFKILL_GLOBAL_OP_EPO = 0,
  45         RFKILL_GLOBAL_OP_RESTORE,
  46         RFKILL_GLOBAL_OP_UNLOCK,
  47         RFKILL_GLOBAL_OP_UNBLOCK,
  48 };
  49
  50 /*
  51  * Currently, the code marked with RFKILL_NEED_SWSET is inactive.
  52  * If handling of EV_SW SW_WLAN/WWAN/BLUETOOTH/etc is needed in the
  53  * future, when such events are added, that code will be necessary.
  54  */
  55
  56 struct rfkill_task {
  57         struct delayed_work dwork;
  58
  59         /* ensures that task is serialized */
  60         struct mutex mutex;
  61
  62         /* protects everything below */
  63         spinlock_t lock;
  64
  65         /* pending regular switch operations (1=pending) */
  66         unsigned long sw_pending[BITS_TO_LONGS(RFKILL_TYPE_MAX)];
  67
  68 #ifdef RFKILL_NEED_SWSET
  69         /* set operation pending (1=pending) */
  70         unsigned long sw_setpending[BITS_TO_LONGS(RFKILL_TYPE_MAX)];
  71
  72         /* desired state for pending set operation (1=unblock) */
  73         unsigned long sw_newstate[BITS_TO_LONGS(RFKILL_TYPE_MAX)];
  74 #endif
  75
  76         /* should the state be complemented (1=yes) */
  77         unsigned long sw_togglestate[BITS_TO_LONGS(RFKILL_TYPE_MAX)];
  78
  79         bool global_op_pending;
  80         enum rfkill_global_sched_op op;
  81
  82         /* last time it was scheduled */
  83         unsigned long last_scheduled;
  84 };
  85
  86 static void __rfkill_handle_global_op(enum rfkill_global_sched_op op)
  87 {
  88         unsigned int i;
  89
  90         switch (op) {
  91         case RFKILL_GLOBAL_OP_EPO:
  92                 rfkill_epo();
  93                 break;
  94         case RFKILL_GLOBAL_OP_RESTORE:
  95                 rfkill_restore_states();
  96                 break;
  97         case RFKILL_GLOBAL_OP_UNLOCK:
  98                 rfkill_remove_epo_lock();
  99                 break;
 100         case RFKILL_GLOBAL_OP_UNBLOCK:
 101                 rfkill_remove_epo_lock();
 102                 for (i = 0; i < RFKILL_TYPE_MAX; i++)
 103                         rfkill_switch_all(i, RFKILL_STATE_UNBLOCKED);
 104                 break;
 105         default:
 106                 /* memory corruption or bug, fail safely */
 107                 rfkill_epo();
 108                 WARN(1, "Unknown requested operation %d! "
 109                         "rfkill Emergency Power Off activated\n",
 110                         op);
 111         }
 112 }
 113
 114 #ifdef RFKILL_NEED_SWSET
 115 static void __rfkill_handle_normal_op(const enum rfkill_type type,
 116                         const bool sp, const bool s, const bool c)
 117 {
 118         enum rfkill_state state;
 119
 120         if (sp)
 121                 state = (s) ? RFKILL_STATE_UNBLOCKED :
 122                               RFKILL_STATE_SOFT_BLOCKED;
 123         else
 124                 state = rfkill_get_global_state(type);
 125
 126         if (c)
 127                 state = rfkill_state_complement(state);
 128
 129         rfkill_switch_all(type, state);
 130 }
 131 #else
 132 static void __rfkill_handle_normal_op(const enum rfkill_type type,
 133                         const bool c)
 134 {
 135         enum rfkill_state state;
 136
 137         state = rfkill_get_global_state(type);
 138         if (c)
 139                 state = rfkill_state_complement(state);
 140
 141         rfkill_switch_all(type, state);
 142 }
 143 #endif
 144
 145 static void rfkill_task_handler(struct work_struct *work)
 146 {
 147         struct rfkill_task *task = container_of(work,
 148                                         struct rfkill_task, dwork.work);
 149         bool doit = true;
 150
 151         mutex_lock(&task->mutex);
 152
 153         spin_lock_irq(&task->lock);
 154         while (doit) {
 155                 if (task->global_op_pending) {
 156                         enum rfkill_global_sched_op op = task->op;
 157                         task->global_op_pending = false;
 158                         memset(task->sw_pending, 0, sizeof(task->sw_pending));
 159                         spin_unlock_irq(&task->lock);
 160
 161                         __rfkill_handle_global_op(op);
 162
 163                         /* make sure we do at least one pass with
 164                          * !task->global_op_pending */
 165                         spin_lock_irq(&task->lock);
 166                         continue;
 167                 } else if (!rfkill_is_epo_lock_active()) {
 168                         unsigned int i = 0;
 169
 170                         while (!task->global_op_pending &&
 171                                                 i < RFKILL_TYPE_MAX) {
 172                                 if (test_and_clear_bit(i, task->sw_pending)) {
 173                                         bool c;
 174 #ifdef RFKILL_NEED_SWSET
 175                                         bool sp, s;
 176                                         sp = test_and_clear_bit(i,
 177                                                         task->sw_setpending);
 178                                         s = test_bit(i, task->sw_newstate);
 179 #endif
 180                                         c = test_and_clear_bit(i,
 181                                                         task->sw_togglestate);
 182                                         spin_unlock_irq(&task->lock);
 183
 184 #ifdef RFKILL_NEED_SWSET
 185                                         __rfkill_handle_normal_op(i, sp, s, c);
 186 #else
 187                                         __rfkill_handle_normal_op(i, c);
 188 #endif
 189
 190                                         spin_lock_irq(&task->lock);
 191                                 }
 192                                 i++;
 193                         }
 194                 }
 195                 doit = task->global_op_pending;
 196         }
 197         spin_unlock_irq(&task->lock);
 198
 199         mutex_unlock(&task->mutex);
 200 }
 201
 202 static struct rfkill_task rfkill_task = {
 203         .dwork = __DELAYED_WORK_INITIALIZER(rfkill_task.dwork,
 204                                 rfkill_task_handler),
 205         .mutex = __MUTEX_INITIALIZER(rfkill_task.mutex),
 206         .lock = __SPIN_LOCK_UNLOCKED(rfkill_task.lock),
 207 };
 208
 209 static unsigned long rfkill_ratelimit(const unsigned long last)
 210 {
 211         const unsigned long delay = msecs_to_jiffies(RFKILL_OPS_DELAY);
 212         return (time_after(jiffies, last + delay)) ? 0 : delay;
 213 }
 214
 215 static void rfkill_schedule_ratelimited(void)
 216 {
 217         if (!delayed_work_pending(&rfkill_task.dwork)) {
 218                 schedule_delayed_work(&rfkill_task.dwork,
 219                                 rfkill_ratelimit(rfkill_task.last_scheduled));
 220                 rfkill_task.last_scheduled = jiffies;
 221         }
 222 }
 223
 224 static void rfkill_schedule_global_op(enum rfkill_global_sched_op op)
 225 {
 226         unsigned long flags;
 227
 228         spin_lock_irqsave(&rfkill_task.lock, flags);
 229         rfkill_task.op = op;
 230         rfkill_task.global_op_pending = true;
 231         if (op == RFKILL_GLOBAL_OP_EPO && !rfkill_is_epo_lock_active()) {
 232                 /* bypass the limiter for EPO */
 233                 cancel_delayed_work(&rfkill_task.dwork);
 234                 schedule_delayed_work(&rfkill_task.dwork, 0);
 235                 rfkill_task.last_scheduled = jiffies;
 236         } else
 237                 rfkill_schedule_ratelimited();
 238         spin_unlock_irqrestore(&rfkill_task.lock, flags);
 239 }
 240
 241 #ifdef RFKILL_NEED_SWSET
 242 /* Use this if you need to add EV_SW SW_WLAN/WWAN/BLUETOOTH/etc handling */
 243
 244 static void rfkill_schedule_set(enum rfkill_type type,
 245                                 enum rfkill_state desired_state)
 246 {
 247         unsigned long flags;
 248
 249         if (rfkill_is_epo_lock_active())
 250                 return;
 251
 252         spin_lock_irqsave(&rfkill_task.lock, flags);
 253         if (!rfkill_task.global_op_pending) {
 254                 set_bit(type, rfkill_task.sw_pending);
 255                 set_bit(type, rfkill_task.sw_setpending);
 256                 clear_bit(type, rfkill_task.sw_togglestate);
 257                 if (desired_state)
 258                         set_bit(type,  rfkill_task.sw_newstate);
 259                 else
 260                         clear_bit(type, rfkill_task.sw_newstate);
 261                 rfkill_schedule_ratelimited();
 262         }
 263         spin_unlock_irqrestore(&rfkill_task.lock, flags);
 264 }
 265 #endif
 266
 267 static void rfkill_schedule_toggle(enum rfkill_type type)
 268 {
 269         unsigned long flags;
 270
 271         if (rfkill_is_epo_lock_active())
 272                 return;
 273
 274         spin_lock_irqsave(&rfkill_task.lock, flags);
 275         if (!rfkill_task.global_op_pending) {
 276                 set_bit(type, rfkill_task.sw_pending);
 277                 change_bit(type, rfkill_task.sw_togglestate);
 278                 rfkill_schedule_ratelimited();
 279         }
 280         spin_unlock_irqrestore(&rfkill_task.lock, flags);
 281 }
 282
 283 static void rfkill_schedule_evsw_rfkillall(int state)
 284 {
 285         if (state) {
 286                 switch (rfkill_master_switch_mode) {
 287                 case RFKILL_INPUT_MASTER_UNBLOCKALL:
 288                         rfkill_schedule_global_op(RFKILL_GLOBAL_OP_UNBLOCK);
 289                         break;
 290                 case RFKILL_INPUT_MASTER_RESTORE:
 291                         rfkill_schedule_global_op(RFKILL_GLOBAL_OP_RESTORE);
 292                         break;
 293                 case RFKILL_INPUT_MASTER_DONOTHING:
 294                         rfkill_schedule_global_op(RFKILL_GLOBAL_OP_UNLOCK);
 295                         break;
 296                 default:
 297                         /* memory corruption or driver bug! fail safely */
 298                         rfkill_schedule_global_op(RFKILL_GLOBAL_OP_EPO);
 299                         WARN(1, "Unknown rfkill_master_switch_mode (%d), "
 300                                 "driver bug or memory corruption detected!\n",
 301                                 rfkill_master_switch_mode);
 302                         break;
 303                 }
 304         } else
 305                 rfkill_schedule_global_op(RFKILL_GLOBAL_OP_EPO);
 306 }
 307
 308 static void rfkill_event(struct input_handle *handle, unsigned int type,
 309                         unsigned int code, int data)
 310 {
 311         if (type == EV_KEY && data == 1) {
 312                 enum rfkill_type t;
 313
 314                 switch (code) {
 315                 case KEY_WLAN:
 316                         t = RFKILL_TYPE_WLAN;
 317                         break;
 318                 case KEY_BLUETOOTH:
 319                         t = RFKILL_TYPE_BLUETOOTH;
 320                         break;
 321                 case KEY_UWB:
 322                         t = RFKILL_TYPE_UWB;
 323                         break;
 324                 case KEY_WIMAX:
 325                         t = RFKILL_TYPE_WIMAX;
 326                         break;
 327                 default:
 328                         return;
 329                 }
 330                 rfkill_schedule_toggle(t);
 331                 return;
 332         } else if (type == EV_SW) {
 333                 switch (code) {
 334                 case SW_RFKILL_ALL:
 335                         rfkill_schedule_evsw_rfkillall(data);
 336                         return;
 337                 default:
 338                         return;
 339                 }
 340         }
 341 }
 342
 343 static int rfkill_connect(struct input_handler *handler, struct input_dev *dev,
 344                           const struct input_device_id *id)
 345 {
 346         struct input_handle *handle;
 347         int error;
 348
 349         handle = kzalloc(sizeof(struct input_handle), GFP_KERNEL);
 350         if (!handle)
 351                 return -ENOMEM;
 352
 353         handle->dev = dev;
 354         handle->handler = handler;
 355         handle->name = "rfkill";
 356
 357         /* causes rfkill_start() to be called */
 358         error = input_register_handle(handle);
 359         if (error)
 360                 goto err_free_handle;
 361
 362         error = input_open_device(handle);
 363         if (error)
 364                 goto err_unregister_handle;
 365
 366         return 0;
 367
 368  err_unregister_handle:
 369         input_unregister_handle(handle);
 370  err_free_handle:
 371         kfree(handle);
 372         return error;
 373 }
 374
 375 static void rfkill_start(struct input_handle *handle)
 376 {
 377         /* Take event_lock to guard against configuration changes, we
 378          * should be able to deal with concurrency with rfkill_event()
 379          * just fine (which event_lock will also avoid). */
 380         spin_lock_irq(&handle->dev->event_lock);
 381
 382         if (test_bit(EV_SW, handle->dev->evbit)) {
 383                 if (test_bit(SW_RFKILL_ALL, handle->dev->swbit))
 384                         rfkill_schedule_evsw_rfkillall(test_bit(SW_RFKILL_ALL,
 385                                                         handle->dev->sw));
 386                 /* add resync for further EV_SW events here */
 387         }
 388
 389         spin_unlock_irq(&handle->dev->event_lock);
 390 }
 391
 392 static void rfkill_disconnect(struct input_handle *handle)
 393 {
 394         input_close_device(handle);
 395         input_unregister_handle(handle);
 396         kfree(handle);
 397 }
 398
 399 static const struct input_device_id rfkill_ids[] = {
 400         {
 401                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 402                 .evbit = { BIT_MASK(EV_KEY) },
 403                 .keybit = { [BIT_WORD(KEY_WLAN)] = BIT_MASK(KEY_WLAN) },
 404         },
 405         {
 406                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 407                 .evbit = { BIT_MASK(EV_KEY) },
 408                 .keybit = { [BIT_WORD(KEY_BLUETOOTH)] = BIT_MASK(KEY_BLUETOOTH) },
 409         },
 410         {
 411                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 412                 .evbit = { BIT_MASK(EV_KEY) },
 413                 .keybit = { [BIT_WORD(KEY_UWB)] = BIT_MASK(KEY_UWB) },
 414         },
 415         {
 416                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 417                 .evbit = { BIT_MASK(EV_KEY) },
 418                 .keybit = { [BIT_WORD(KEY_WIMAX)] = BIT_MASK(KEY_WIMAX) },
 419         },
 420         {
 421                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_SWBIT,
 422                 .evbit = { BIT(EV_SW) },
 423                 .swbit = { [BIT_WORD(SW_RFKILL_ALL)] = BIT_MASK(SW_RFKILL_ALL) },
 424         },
 425         { }
 426 };
 427
 428 static struct input_handler rfkill_handler = {
 429         .event =        rfkill_event,
 430         .connect =      rfkill_connect,
 431         .disconnect =   rfkill_disconnect,
 432         .start =        rfkill_start,
 433         .name =         "rfkill",
 434         .id_table =     rfkill_ids,
 435 };
 436
 437 static int __init rfkill_handler_init(void)
 438 {
 439         if (rfkill_master_switch_mode >= RFKILL_INPUT_MASTER_MAX)
 440                 return -EINVAL;
 441
 442         /*
 443          * The penalty to not doing this is a possible RFKILL_OPS_DELAY delay
 444          * at the first use.  Acceptable, but if we can avoid it, why not?
 445          */
 446         rfkill_task.last_scheduled =
 447                         jiffies - msecs_to_jiffies(RFKILL_OPS_DELAY) - 1;
 448         return input_register_handler(&rfkill_handler);
 449 }
 450
 451 static void __exit rfkill_handler_exit(void)
 452 {
 453         input_unregister_handler(&rfkill_handler);
 454         cancel_delayed_work_sync(&rfkill_task.dwork);
 455         rfkill_remove_epo_lock();
 456 }
 457
 458 module_init(rfkill_handler_init);
 459 module_exit(rfkill_handler_exit);