net/rfkill/input.c

   1 /*
   2  * Input layer to RF Kill interface connector
   3  *
   4  * Copyright (c) 2007 Dmitry Torokhov
   5  * Copyright 2009 Johannes Berg <johannes@sipsolutions.net>
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License version 2 as published
   9  * by the Free Software Foundation.
  10  *
  11  * If you ever run into a situation in which you have a SW_ type rfkill
  12  * input device, then you can revive code that was removed in the patch
  13  * "rfkill-input: remove unused code".
  14  */
  15
  16 #include <linux/input.h>
  17 #include <linux/slab.h>
  18 #include <linux/moduleparam.h>
  19 #include <linux/workqueue.h>
  20 #include <linux/init.h>
  21 #include <linux/rfkill.h>
  22 #include <linux/sched.h>
  23
  24 #include "rfkill.h"
  25
  26 enum rfkill_input_master_mode {
  27         RFKILL_INPUT_MASTER_UNLOCK = 0,
  28         RFKILL_INPUT_MASTER_RESTORE = 1,
  29         RFKILL_INPUT_MASTER_UNBLOCKALL = 2,
  30         NUM_RFKILL_INPUT_MASTER_MODES
  31 };
  32
  33 /* Delay (in ms) between consecutive switch ops */
  34 #define RFKILL_OPS_DELAY 200
  35
  36 static enum rfkill_input_master_mode rfkill_master_switch_mode =
  37                                         RFKILL_INPUT_MASTER_UNBLOCKALL;
  38 module_param_named(master_switch_mode, rfkill_master_switch_mode, uint, 0);
  39 MODULE_PARM_DESC(master_switch_mode,
  40         "SW_RFKILL_ALL ON should: 0=do nothing (only unlock); 1=restore; 2=unblock all");
  41
  42 static spinlock_t rfkill_op_lock;
  43 static bool rfkill_op_pending;
  44 static unsigned long rfkill_sw_pending[BITS_TO_LONGS(NUM_RFKILL_TYPES)];
  45 static unsigned long rfkill_sw_state[BITS_TO_LONGS(NUM_RFKILL_TYPES)];
  46
  47 enum rfkill_sched_op {
  48         RFKILL_GLOBAL_OP_EPO = 0,
  49         RFKILL_GLOBAL_OP_RESTORE,
  50         RFKILL_GLOBAL_OP_UNLOCK,
  51         RFKILL_GLOBAL_OP_UNBLOCK,
  52 };
  53
  54 static enum rfkill_sched_op rfkill_master_switch_op;
  55 static enum rfkill_sched_op rfkill_op;
  56
  57 static void __rfkill_handle_global_op(enum rfkill_sched_op op)
  58 {
  59         unsigned int i;
  60
  61         switch (op) {
  62         case RFKILL_GLOBAL_OP_EPO:
  63                 rfkill_epo();
  64                 break;
  65         case RFKILL_GLOBAL_OP_RESTORE:
  66                 rfkill_restore_states();
  67                 break;
  68         case RFKILL_GLOBAL_OP_UNLOCK:
  69                 rfkill_remove_epo_lock();
  70                 break;
  71         case RFKILL_GLOBAL_OP_UNBLOCK:
  72                 rfkill_remove_epo_lock();
  73                 for (i = 0; i < NUM_RFKILL_TYPES; i++)
  74                         rfkill_switch_all(i, false);
  75                 break;
  76         default:
  77                 /* memory corruption or bug, fail safely */
  78                 rfkill_epo();
  79                 WARN(1, "Unknown requested operation %d! "
  80                         "rfkill Emergency Power Off activated\n",
  81                         op);
  82         }
  83 }
  84
  85 static void __rfkill_handle_normal_op(const enum rfkill_type type,
  86                                       const bool complement)
  87 {
  88         bool blocked;
  89
  90         blocked = rfkill_get_global_sw_state(type);
  91         if (complement)
  92                 blocked = !blocked;
  93
  94         rfkill_switch_all(type, blocked);
  95 }
  96
  97 static void rfkill_op_handler(struct work_struct *work)
  98 {
  99         unsigned int i;
 100         bool c;
 101
 102         spin_lock_irq(&rfkill_op_lock);
 103         do {
 104                 if (rfkill_op_pending) {
 105                         enum rfkill_sched_op op = rfkill_op;
 106                         rfkill_op_pending = false;
 107                         memset(rfkill_sw_pending, 0,
 108                                 sizeof(rfkill_sw_pending));
 109                         spin_unlock_irq(&rfkill_op_lock);
 110
 111                         __rfkill_handle_global_op(op);
 112
 113                         spin_lock_irq(&rfkill_op_lock);
 114
 115                         /*
 116                          * handle global ops first -- during unlocked period
 117                          * we might have gotten a new global op.
 118                          */
 119                         if (rfkill_op_pending)
 120                                 continue;
 121                 }
 122
 123                 if (rfkill_is_epo_lock_active())
 124                         continue;
 125
 126                 for (i = 0; i < NUM_RFKILL_TYPES; i++) {
 127                         if (__test_and_clear_bit(i, rfkill_sw_pending)) {
 128                                 c = __test_and_clear_bit(i, rfkill_sw_state);
 129                                 spin_unlock_irq(&rfkill_op_lock);
 130
 131                                 __rfkill_handle_normal_op(i, c);
 132
 133                                 spin_lock_irq(&rfkill_op_lock);
 134                         }
 135                 }
 136         } while (rfkill_op_pending);
 137         spin_unlock_irq(&rfkill_op_lock);
 138 }
 139
 140 static DECLARE_DELAYED_WORK(rfkill_op_work, rfkill_op_handler);
 141 static unsigned long rfkill_last_scheduled;
 142
 143 static unsigned long rfkill_ratelimit(const unsigned long last)
 144 {
 145         const unsigned long delay = msecs_to_jiffies(RFKILL_OPS_DELAY);
 146         return time_after(jiffies, last + delay) ? 0 : delay;
 147 }
 148
 149 static void rfkill_schedule_ratelimited(void)
 150 {
 151         if (delayed_work_pending(&rfkill_op_work))
 152                 return;
 153         schedule_delayed_work(&rfkill_op_work,
 154                               rfkill_ratelimit(rfkill_last_scheduled));
 155         rfkill_last_scheduled = jiffies;
 156 }
 157
 158 static void rfkill_schedule_global_op(enum rfkill_sched_op op)
 159 {
 160         unsigned long flags;
 161
 162         spin_lock_irqsave(&rfkill_op_lock, flags);
 163         rfkill_op = op;
 164         rfkill_op_pending = true;
 165         if (op == RFKILL_GLOBAL_OP_EPO && !rfkill_is_epo_lock_active()) {
 166                 /* bypass the limiter for EPO */
 167                 cancel_delayed_work(&rfkill_op_work);
 168                 schedule_delayed_work(&rfkill_op_work, 0);
 169                 rfkill_last_scheduled = jiffies;
 170         } else
 171                 rfkill_schedule_ratelimited();
 172         spin_unlock_irqrestore(&rfkill_op_lock, flags);
 173 }
 174
 175 static void rfkill_schedule_toggle(enum rfkill_type type)
 176 {
 177         unsigned long flags;
 178
 179         if (rfkill_is_epo_lock_active())
 180                 return;
 181
 182         spin_lock_irqsave(&rfkill_op_lock, flags);
 183         if (!rfkill_op_pending) {
 184                 __set_bit(type, rfkill_sw_pending);
 185                 __change_bit(type, rfkill_sw_state);
 186                 rfkill_schedule_ratelimited();
 187         }
 188         spin_unlock_irqrestore(&rfkill_op_lock, flags);
 189 }
 190
 191 static void rfkill_schedule_evsw_rfkillall(int state)
 192 {
 193         if (state)
 194                 rfkill_schedule_global_op(rfkill_master_switch_op);
 195         else
 196                 rfkill_schedule_global_op(RFKILL_GLOBAL_OP_EPO);
 197 }
 198
 199 static void rfkill_event(struct input_handle *handle, unsigned int type,
 200                         unsigned int code, int data)
 201 {
 202         if (type == EV_KEY && data == 1) {
 203                 switch (code) {
 204                 case KEY_WLAN:
 205                         rfkill_schedule_toggle(RFKILL_TYPE_WLAN);
 206                         break;
 207                 case KEY_BLUETOOTH:
 208                         rfkill_schedule_toggle(RFKILL_TYPE_BLUETOOTH);
 209                         break;
 210                 case KEY_UWB:
 211                         rfkill_schedule_toggle(RFKILL_TYPE_UWB);
 212                         break;
 213                 case KEY_WIMAX:
 214                         rfkill_schedule_toggle(RFKILL_TYPE_WIMAX);
 215                         break;
 216                 case KEY_RFKILL:
 217                         rfkill_schedule_toggle(RFKILL_TYPE_ALL);
 218                         break;
 219                 }
 220         } else if (type == EV_SW && code == SW_RFKILL_ALL)
 221                 rfkill_schedule_evsw_rfkillall(data);
 222 }
 223
 224 static int rfkill_connect(struct input_handler *handler, struct input_dev *dev,
 225                           const struct input_device_id *id)
 226 {
 227         struct input_handle *handle;
 228         int error;
 229
 230         handle = kzalloc(sizeof(struct input_handle), GFP_KERNEL);
 231         if (!handle)
 232                 return -ENOMEM;
 233
 234         handle->dev = dev;
 235         handle->handler = handler;
 236         handle->name = "rfkill";
 237
 238         /* causes rfkill_start() to be called */
 239         error = input_register_handle(handle);
 240         if (error)
 241                 goto err_free_handle;
 242
 243         error = input_open_device(handle);
 244         if (error)
 245                 goto err_unregister_handle;
 246
 247         return 0;
 248
 249  err_unregister_handle:
 250         input_unregister_handle(handle);
 251  err_free_handle:
 252         kfree(handle);
 253         return error;
 254 }
 255
 256 static void rfkill_start(struct input_handle *handle)
 257 {
 258         /*
 259          * Take event_lock to guard against configuration changes, we
 260          * should be able to deal with concurrency with rfkill_event()
 261          * just fine (which event_lock will also avoid).
 262          */
 263         spin_lock_irq(&handle->dev->event_lock);
 264
 265         if (test_bit(EV_SW, handle->dev->evbit) &&
 266             test_bit(SW_RFKILL_ALL, handle->dev->swbit))
 267                 rfkill_schedule_evsw_rfkillall(test_bit(SW_RFKILL_ALL,
 268                                                         handle->dev->sw));
 269
 270         spin_unlock_irq(&handle->dev->event_lock);
 271 }
 272
 273 static void rfkill_disconnect(struct input_handle *handle)
 274 {
 275         input_close_device(handle);
 276         input_unregister_handle(handle);
 277         kfree(handle);
 278 }
 279
 280 static const struct input_device_id rfkill_ids[] = {
 281         {
 282                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 283                 .evbit = { BIT_MASK(EV_KEY) },
 284                 .keybit = { [BIT_WORD(KEY_WLAN)] = BIT_MASK(KEY_WLAN) },
 285         },
 286         {
 287                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 288                 .evbit = { BIT_MASK(EV_KEY) },
 289                 .keybit = { [BIT_WORD(KEY_BLUETOOTH)] = BIT_MASK(KEY_BLUETOOTH) },
 290         },
 291         {
 292                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 293                 .evbit = { BIT_MASK(EV_KEY) },
 294                 .keybit = { [BIT_WORD(KEY_UWB)] = BIT_MASK(KEY_UWB) },
 295         },
 296         {
 297                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 298                 .evbit = { BIT_MASK(EV_KEY) },
 299                 .keybit = { [BIT_WORD(KEY_WIMAX)] = BIT_MASK(KEY_WIMAX) },
 300         },
 301         {
 302                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 303                 .evbit = { BIT_MASK(EV_KEY) },
 304                 .keybit = { [BIT_WORD(KEY_RFKILL)] = BIT_MASK(KEY_RFKILL) },
 305         },
 306         {
 307                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_SWBIT,
 308                 .evbit = { BIT(EV_SW) },
 309                 .swbit = { [BIT_WORD(SW_RFKILL_ALL)] = BIT_MASK(SW_RFKILL_ALL) },
 310         },
 311         { }
 312 };
 313
 314 static struct input_handler rfkill_handler = {
 315         .name = "rfkill",
 316         .event = rfkill_event,
 317         .connect = rfkill_connect,
 318         .start = rfkill_start,
 319         .disconnect = rfkill_disconnect,
 320         .id_table = rfkill_ids,
 321 };
 322
 323 int __init rfkill_handler_init(void)
 324 {
 325         switch (rfkill_master_switch_mode) {
 326         case RFKILL_INPUT_MASTER_UNBLOCKALL:
 327                 rfkill_master_switch_op = RFKILL_GLOBAL_OP_UNBLOCK;
 328                 break;
 329         case RFKILL_INPUT_MASTER_RESTORE:
 330                 rfkill_master_switch_op = RFKILL_GLOBAL_OP_RESTORE;
 331                 break;
 332         case RFKILL_INPUT_MASTER_UNLOCK:
 333                 rfkill_master_switch_op = RFKILL_GLOBAL_OP_UNLOCK;
 334                 break;
 335         default:
 336                 return -EINVAL;
 337         }
 338
 339         spin_lock_init(&rfkill_op_lock);
 340
 341         /* Avoid delay at first schedule */
 342         rfkill_last_scheduled =
 343                         jiffies - msecs_to_jiffies(RFKILL_OPS_DELAY) - 1;
 344         return input_register_handler(&rfkill_handler);
 345 }
 346
 347 void __exit rfkill_handler_exit(void)
 348 {
 349         input_unregister_handler(&rfkill_handler);
 350         cancel_delayed_work_sync(&rfkill_op_work);
 351 }