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 (schedule_delayed_work(&rfkill_op_work,
 152                                   rfkill_ratelimit(rfkill_last_scheduled)))
 153                 rfkill_last_scheduled = jiffies;
 154 }
 155
 156 static void rfkill_schedule_global_op(enum rfkill_sched_op op)
 157 {
 158         unsigned long flags;
 159
 160         spin_lock_irqsave(&rfkill_op_lock, flags);
 161         rfkill_op = op;
 162         rfkill_op_pending = true;
 163         if (op == RFKILL_GLOBAL_OP_EPO && !rfkill_is_epo_lock_active()) {
 164                 /* bypass the limiter for EPO */
 165                 mod_delayed_work(system_wq, &rfkill_op_work, 0);
 166                 rfkill_last_scheduled = jiffies;
 167         } else
 168                 rfkill_schedule_ratelimited();
 169         spin_unlock_irqrestore(&rfkill_op_lock, flags);
 170 }
 171
 172 static void rfkill_schedule_toggle(enum rfkill_type type)
 173 {
 174         unsigned long flags;
 175
 176         if (rfkill_is_epo_lock_active())
 177                 return;
 178
 179         spin_lock_irqsave(&rfkill_op_lock, flags);
 180         if (!rfkill_op_pending) {
 181                 __set_bit(type, rfkill_sw_pending);
 182                 __change_bit(type, rfkill_sw_state);
 183                 rfkill_schedule_ratelimited();
 184         }
 185         spin_unlock_irqrestore(&rfkill_op_lock, flags);
 186 }
 187
 188 static void rfkill_schedule_evsw_rfkillall(int state)
 189 {
 190         if (state)
 191                 rfkill_schedule_global_op(rfkill_master_switch_op);
 192         else
 193                 rfkill_schedule_global_op(RFKILL_GLOBAL_OP_EPO);
 194 }
 195
 196 static void rfkill_event(struct input_handle *handle, unsigned int type,
 197                         unsigned int code, int data)
 198 {
 199         if (type == EV_KEY && data == 1) {
 200                 switch (code) {
 201                 case KEY_WLAN:
 202                         rfkill_schedule_toggle(RFKILL_TYPE_WLAN);
 203                         break;
 204                 case KEY_BLUETOOTH:
 205                         rfkill_schedule_toggle(RFKILL_TYPE_BLUETOOTH);
 206                         break;
 207                 case KEY_UWB:
 208                         rfkill_schedule_toggle(RFKILL_TYPE_UWB);
 209                         break;
 210                 case KEY_WIMAX:
 211                         rfkill_schedule_toggle(RFKILL_TYPE_WIMAX);
 212                         break;
 213                 case KEY_RFKILL:
 214                         rfkill_schedule_toggle(RFKILL_TYPE_ALL);
 215                         break;
 216                 }
 217         } else if (type == EV_SW && code == SW_RFKILL_ALL)
 218                 rfkill_schedule_evsw_rfkillall(data);
 219 }
 220
 221 static int rfkill_connect(struct input_handler *handler, struct input_dev *dev,
 222                           const struct input_device_id *id)
 223 {
 224         struct input_handle *handle;
 225         int error;
 226
 227         handle = kzalloc(sizeof(struct input_handle), GFP_KERNEL);
 228         if (!handle)
 229                 return -ENOMEM;
 230
 231         handle->dev = dev;
 232         handle->handler = handler;
 233         handle->name = "rfkill";
 234
 235         /* causes rfkill_start() to be called */
 236         error = input_register_handle(handle);
 237         if (error)
 238                 goto err_free_handle;
 239
 240         error = input_open_device(handle);
 241         if (error)
 242                 goto err_unregister_handle;
 243
 244         return 0;
 245
 246  err_unregister_handle:
 247         input_unregister_handle(handle);
 248  err_free_handle:
 249         kfree(handle);
 250         return error;
 251 }
 252
 253 static void rfkill_start(struct input_handle *handle)
 254 {
 255         /*
 256          * Take event_lock to guard against configuration changes, we
 257          * should be able to deal with concurrency with rfkill_event()
 258          * just fine (which event_lock will also avoid).
 259          */
 260         spin_lock_irq(&handle->dev->event_lock);
 261
 262         if (test_bit(EV_SW, handle->dev->evbit) &&
 263             test_bit(SW_RFKILL_ALL, handle->dev->swbit))
 264                 rfkill_schedule_evsw_rfkillall(test_bit(SW_RFKILL_ALL,
 265                                                         handle->dev->sw));
 266
 267         spin_unlock_irq(&handle->dev->event_lock);
 268 }
 269
 270 static void rfkill_disconnect(struct input_handle *handle)
 271 {
 272         input_close_device(handle);
 273         input_unregister_handle(handle);
 274         kfree(handle);
 275 }
 276
 277 static const struct input_device_id rfkill_ids[] = {
 278         {
 279                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 280                 .evbit = { BIT_MASK(EV_KEY) },
 281                 .keybit = { [BIT_WORD(KEY_WLAN)] = BIT_MASK(KEY_WLAN) },
 282         },
 283         {
 284                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 285                 .evbit = { BIT_MASK(EV_KEY) },
 286                 .keybit = { [BIT_WORD(KEY_BLUETOOTH)] = BIT_MASK(KEY_BLUETOOTH) },
 287         },
 288         {
 289                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 290                 .evbit = { BIT_MASK(EV_KEY) },
 291                 .keybit = { [BIT_WORD(KEY_UWB)] = BIT_MASK(KEY_UWB) },
 292         },
 293         {
 294                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 295                 .evbit = { BIT_MASK(EV_KEY) },
 296                 .keybit = { [BIT_WORD(KEY_WIMAX)] = BIT_MASK(KEY_WIMAX) },
 297         },
 298         {
 299                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 300                 .evbit = { BIT_MASK(EV_KEY) },
 301                 .keybit = { [BIT_WORD(KEY_RFKILL)] = BIT_MASK(KEY_RFKILL) },
 302         },
 303         {
 304                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_SWBIT,
 305                 .evbit = { BIT(EV_SW) },
 306                 .swbit = { [BIT_WORD(SW_RFKILL_ALL)] = BIT_MASK(SW_RFKILL_ALL) },
 307         },
 308         { }
 309 };
 310
 311 static struct input_handler rfkill_handler = {
 312         .name = "rfkill",
 313         .event = rfkill_event,
 314         .connect = rfkill_connect,
 315         .start = rfkill_start,
 316         .disconnect = rfkill_disconnect,
 317         .id_table = rfkill_ids,
 318 };
 319
 320 int __init rfkill_handler_init(void)
 321 {
 322         switch (rfkill_master_switch_mode) {
 323         case RFKILL_INPUT_MASTER_UNBLOCKALL:
 324                 rfkill_master_switch_op = RFKILL_GLOBAL_OP_UNBLOCK;
 325                 break;
 326         case RFKILL_INPUT_MASTER_RESTORE:
 327                 rfkill_master_switch_op = RFKILL_GLOBAL_OP_RESTORE;
 328                 break;
 329         case RFKILL_INPUT_MASTER_UNLOCK:
 330                 rfkill_master_switch_op = RFKILL_GLOBAL_OP_UNLOCK;
 331                 break;
 332         default:
 333                 return -EINVAL;
 334         }
 335
 336         spin_lock_init(&rfkill_op_lock);
 337
 338         /* Avoid delay at first schedule */
 339         rfkill_last_scheduled =
 340                         jiffies - msecs_to_jiffies(RFKILL_OPS_DELAY) - 1;
 341         return input_register_handler(&rfkill_handler);
 342 }
 343
 344 void __exit rfkill_handler_exit(void)
 345 {
 346         input_unregister_handler(&rfkill_handler);
 347         cancel_delayed_work_sync(&rfkill_op_work);
 348 }