net/rfkill/input.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Input layer to RF Kill interface connector
   4  *
   5  * Copyright (c) 2007 Dmitry Torokhov
   6  * Copyright 2009 Johannes Berg <johannes@sipsolutions.net>
   7  *
   8  * If you ever run into a situation in which you have a SW_ type rfkill
   9  * input device, then you can revive code that was removed in the patch
  10  * "rfkill-input: remove unused code".
  11  */
  12
  13 #include <linux/input.h>
  14 #include <linux/slab.h>
  15 #include <linux/moduleparam.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.h"
  22
  23 enum rfkill_input_master_mode {
  24         RFKILL_INPUT_MASTER_UNLOCK = 0,
  25         RFKILL_INPUT_MASTER_RESTORE = 1,
  26         RFKILL_INPUT_MASTER_UNBLOCKALL = 2,
  27         NUM_RFKILL_INPUT_MASTER_MODES
  28 };
  29
  30 /* Delay (in ms) between consecutive switch ops */
  31 #define RFKILL_OPS_DELAY 200
  32
  33 static enum rfkill_input_master_mode rfkill_master_switch_mode =
  34                                         RFKILL_INPUT_MASTER_UNBLOCKALL;
  35 module_param_named(master_switch_mode, rfkill_master_switch_mode, uint, 0);
  36 MODULE_PARM_DESC(master_switch_mode,
  37         "SW_RFKILL_ALL ON should: 0=do nothing (only unlock); 1=restore; 2=unblock all");
  38
  39 static DEFINE_SPINLOCK(rfkill_op_lock);
  40 static bool rfkill_op_pending;
  41 static unsigned long rfkill_sw_pending[BITS_TO_LONGS(NUM_RFKILL_TYPES)];
  42 static unsigned long rfkill_sw_state[BITS_TO_LONGS(NUM_RFKILL_TYPES)];
  43
  44 enum rfkill_sched_op {
  45         RFKILL_GLOBAL_OP_EPO = 0,
  46         RFKILL_GLOBAL_OP_RESTORE,
  47         RFKILL_GLOBAL_OP_UNLOCK,
  48         RFKILL_GLOBAL_OP_UNBLOCK,
  49 };
  50
  51 static enum rfkill_sched_op rfkill_master_switch_op;
  52 static enum rfkill_sched_op rfkill_op;
  53
  54 static void __rfkill_handle_global_op(enum rfkill_sched_op op)
  55 {
  56         unsigned int i;
  57
  58         switch (op) {
  59         case RFKILL_GLOBAL_OP_EPO:
  60                 rfkill_epo();
  61                 break;
  62         case RFKILL_GLOBAL_OP_RESTORE:
  63                 rfkill_restore_states();
  64                 break;
  65         case RFKILL_GLOBAL_OP_UNLOCK:
  66                 rfkill_remove_epo_lock();
  67                 break;
  68         case RFKILL_GLOBAL_OP_UNBLOCK:
  69                 rfkill_remove_epo_lock();
  70                 for (i = 0; i < NUM_RFKILL_TYPES; i++)
  71                         rfkill_switch_all(i, false);
  72                 break;
  73         default:
  74                 /* memory corruption or bug, fail safely */
  75                 rfkill_epo();
  76                 WARN(1, "Unknown requested operation %d! "
  77                         "rfkill Emergency Power Off activated\n",
  78                         op);
  79         }
  80 }
  81
  82 static void __rfkill_handle_normal_op(const enum rfkill_type type,
  83                                       const bool complement)
  84 {
  85         bool blocked;
  86
  87         blocked = rfkill_get_global_sw_state(type);
  88         if (complement)
  89                 blocked = !blocked;
  90
  91         rfkill_switch_all(type, blocked);
  92 }
  93
  94 static void rfkill_op_handler(struct work_struct *work)
  95 {
  96         unsigned int i;
  97         bool c;
  98
  99         spin_lock_irq(&rfkill_op_lock);
 100         do {
 101                 if (rfkill_op_pending) {
 102                         enum rfkill_sched_op op = rfkill_op;
 103                         rfkill_op_pending = false;
 104                         memset(rfkill_sw_pending, 0,
 105                                 sizeof(rfkill_sw_pending));
 106                         spin_unlock_irq(&rfkill_op_lock);
 107
 108                         __rfkill_handle_global_op(op);
 109
 110                         spin_lock_irq(&rfkill_op_lock);
 111
 112                         /*
 113                          * handle global ops first -- during unlocked period
 114                          * we might have gotten a new global op.
 115                          */
 116                         if (rfkill_op_pending)
 117                                 continue;
 118                 }
 119
 120                 if (rfkill_is_epo_lock_active())
 121                         continue;
 122
 123                 for (i = 0; i < NUM_RFKILL_TYPES; i++) {
 124                         if (__test_and_clear_bit(i, rfkill_sw_pending)) {
 125                                 c = __test_and_clear_bit(i, rfkill_sw_state);
 126                                 spin_unlock_irq(&rfkill_op_lock);
 127
 128                                 __rfkill_handle_normal_op(i, c);
 129
 130                                 spin_lock_irq(&rfkill_op_lock);
 131                         }
 132                 }
 133         } while (rfkill_op_pending);
 134         spin_unlock_irq(&rfkill_op_lock);
 135 }
 136
 137 static DECLARE_DELAYED_WORK(rfkill_op_work, rfkill_op_handler);
 138 static unsigned long rfkill_last_scheduled;
 139
 140 static unsigned long rfkill_ratelimit(const unsigned long last)
 141 {
 142         const unsigned long delay = msecs_to_jiffies(RFKILL_OPS_DELAY);
 143         return time_after(jiffies, last + delay) ? 0 : delay;
 144 }
 145
 146 static void rfkill_schedule_ratelimited(void)
 147 {
 148         if (schedule_delayed_work(&rfkill_op_work,
 149                                   rfkill_ratelimit(rfkill_last_scheduled)))
 150                 rfkill_last_scheduled = jiffies;
 151 }
 152
 153 static void rfkill_schedule_global_op(enum rfkill_sched_op op)
 154 {
 155         unsigned long flags;
 156
 157         spin_lock_irqsave(&rfkill_op_lock, flags);
 158         rfkill_op = op;
 159         rfkill_op_pending = true;
 160         if (op == RFKILL_GLOBAL_OP_EPO && !rfkill_is_epo_lock_active()) {
 161                 /* bypass the limiter for EPO */
 162                 mod_delayed_work(system_wq, &rfkill_op_work, 0);
 163                 rfkill_last_scheduled = jiffies;
 164         } else
 165                 rfkill_schedule_ratelimited();
 166         spin_unlock_irqrestore(&rfkill_op_lock, flags);
 167 }
 168
 169 static void rfkill_schedule_toggle(enum rfkill_type type)
 170 {
 171         unsigned long flags;
 172
 173         if (rfkill_is_epo_lock_active())
 174                 return;
 175
 176         spin_lock_irqsave(&rfkill_op_lock, flags);
 177         if (!rfkill_op_pending) {
 178                 __set_bit(type, rfkill_sw_pending);
 179                 __change_bit(type, rfkill_sw_state);
 180                 rfkill_schedule_ratelimited();
 181         }
 182         spin_unlock_irqrestore(&rfkill_op_lock, flags);
 183 }
 184
 185 static void rfkill_schedule_evsw_rfkillall(int state)
 186 {
 187         if (state)
 188                 rfkill_schedule_global_op(rfkill_master_switch_op);
 189         else
 190                 rfkill_schedule_global_op(RFKILL_GLOBAL_OP_EPO);
 191 }
 192
 193 static void rfkill_event(struct input_handle *handle, unsigned int type,
 194                         unsigned int code, int data)
 195 {
 196         if (type == EV_KEY && data == 1) {
 197                 switch (code) {
 198                 case KEY_WLAN:
 199                         rfkill_schedule_toggle(RFKILL_TYPE_WLAN);
 200                         break;
 201                 case KEY_BLUETOOTH:
 202                         rfkill_schedule_toggle(RFKILL_TYPE_BLUETOOTH);
 203                         break;
 204                 case KEY_UWB:
 205                         rfkill_schedule_toggle(RFKILL_TYPE_UWB);
 206                         break;
 207                 case KEY_WIMAX:
 208                         rfkill_schedule_toggle(RFKILL_TYPE_WIMAX);
 209                         break;
 210                 case KEY_RFKILL:
 211                         rfkill_schedule_toggle(RFKILL_TYPE_ALL);
 212                         break;
 213                 }
 214         } else if (type == EV_SW && code == SW_RFKILL_ALL)
 215                 rfkill_schedule_evsw_rfkillall(data);
 216 }
 217
 218 static int rfkill_connect(struct input_handler *handler, struct input_dev *dev,
 219                           const struct input_device_id *id)
 220 {
 221         struct input_handle *handle;
 222         int error;
 223
 224         handle = kzalloc(sizeof(struct input_handle), GFP_KERNEL);
 225         if (!handle)
 226                 return -ENOMEM;
 227
 228         handle->dev = dev;
 229         handle->handler = handler;
 230         handle->name = "rfkill";
 231
 232         /* causes rfkill_start() to be called */
 233         error = input_register_handle(handle);
 234         if (error)
 235                 goto err_free_handle;
 236
 237         error = input_open_device(handle);
 238         if (error)
 239                 goto err_unregister_handle;
 240
 241         return 0;
 242
 243  err_unregister_handle:
 244         input_unregister_handle(handle);
 245  err_free_handle:
 246         kfree(handle);
 247         return error;
 248 }
 249
 250 static void rfkill_start(struct input_handle *handle)
 251 {
 252         /*
 253          * Take event_lock to guard against configuration changes, we
 254          * should be able to deal with concurrency with rfkill_event()
 255          * just fine (which event_lock will also avoid).
 256          */
 257         spin_lock_irq(&handle->dev->event_lock);
 258
 259         if (test_bit(EV_SW, handle->dev->evbit) &&
 260             test_bit(SW_RFKILL_ALL, handle->dev->swbit))
 261                 rfkill_schedule_evsw_rfkillall(test_bit(SW_RFKILL_ALL,
 262                                                         handle->dev->sw));
 263
 264         spin_unlock_irq(&handle->dev->event_lock);
 265 }
 266
 267 static void rfkill_disconnect(struct input_handle *handle)
 268 {
 269         input_close_device(handle);
 270         input_unregister_handle(handle);
 271         kfree(handle);
 272 }
 273
 274 static const struct input_device_id rfkill_ids[] = {
 275         {
 276                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 277                 .evbit = { BIT_MASK(EV_KEY) },
 278                 .keybit = { [BIT_WORD(KEY_WLAN)] = BIT_MASK(KEY_WLAN) },
 279         },
 280         {
 281                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 282                 .evbit = { BIT_MASK(EV_KEY) },
 283                 .keybit = { [BIT_WORD(KEY_BLUETOOTH)] = BIT_MASK(KEY_BLUETOOTH) },
 284         },
 285         {
 286                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 287                 .evbit = { BIT_MASK(EV_KEY) },
 288                 .keybit = { [BIT_WORD(KEY_UWB)] = BIT_MASK(KEY_UWB) },
 289         },
 290         {
 291                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 292                 .evbit = { BIT_MASK(EV_KEY) },
 293                 .keybit = { [BIT_WORD(KEY_WIMAX)] = BIT_MASK(KEY_WIMAX) },
 294         },
 295         {
 296                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 297                 .evbit = { BIT_MASK(EV_KEY) },
 298                 .keybit = { [BIT_WORD(KEY_RFKILL)] = BIT_MASK(KEY_RFKILL) },
 299         },
 300         {
 301                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_SWBIT,
 302                 .evbit = { BIT(EV_SW) },
 303                 .swbit = { [BIT_WORD(SW_RFKILL_ALL)] = BIT_MASK(SW_RFKILL_ALL) },
 304         },
 305         { }
 306 };
 307
 308 static struct input_handler rfkill_handler = {
 309         .name = "rfkill",
 310         .event = rfkill_event,
 311         .connect = rfkill_connect,
 312         .start = rfkill_start,
 313         .disconnect = rfkill_disconnect,
 314         .id_table = rfkill_ids,
 315 };
 316
 317 int __init rfkill_handler_init(void)
 318 {
 319         switch (rfkill_master_switch_mode) {
 320         case RFKILL_INPUT_MASTER_UNBLOCKALL:
 321                 rfkill_master_switch_op = RFKILL_GLOBAL_OP_UNBLOCK;
 322                 break;
 323         case RFKILL_INPUT_MASTER_RESTORE:
 324                 rfkill_master_switch_op = RFKILL_GLOBAL_OP_RESTORE;
 325                 break;
 326         case RFKILL_INPUT_MASTER_UNLOCK:
 327                 rfkill_master_switch_op = RFKILL_GLOBAL_OP_UNLOCK;
 328                 break;
 329         default:
 330                 return -EINVAL;
 331         }
 332
 333         /* Avoid delay at first schedule */
 334         rfkill_last_scheduled =
 335                         jiffies - msecs_to_jiffies(RFKILL_OPS_DELAY) - 1;
 336         return input_register_handler(&rfkill_handler);
 337 }
 338
 339 void __exit rfkill_handler_exit(void)
 340 {
 341         input_unregister_handler(&rfkill_handler);
 342         cancel_delayed_work_sync(&rfkill_op_work);
 343 }