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