linux/net/rfkill/input.c
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   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
  26enum 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
  36static enum rfkill_input_master_mode rfkill_master_switch_mode =
  37                                        RFKILL_INPUT_MASTER_UNBLOCKALL;
  38module_param_named(master_switch_mode, rfkill_master_switch_mode, uint, 0);
  39MODULE_PARM_DESC(master_switch_mode,
  40        "SW_RFKILL_ALL ON should: 0=do nothing (only unlock); 1=restore; 2=unblock all");
  41
  42static spinlock_t rfkill_op_lock;
  43static bool rfkill_op_pending;
  44static unsigned long rfkill_sw_pending[BITS_TO_LONGS(NUM_RFKILL_TYPES)];
  45static unsigned long rfkill_sw_state[BITS_TO_LONGS(NUM_RFKILL_TYPES)];
  46
  47enum 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
  54static enum rfkill_sched_op rfkill_master_switch_op;
  55static enum rfkill_sched_op rfkill_op;
  56
  57static 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
  85static 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
  97static 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
 140static DECLARE_DELAYED_WORK(rfkill_op_work, rfkill_op_handler);
 141static unsigned long rfkill_last_scheduled;
 142
 143static 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
 149static 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
 156static 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
 172static 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
 188static 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
 196static 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
 221static 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
 253static 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
 270static void rfkill_disconnect(struct input_handle *handle)
 271{
 272        input_close_device(handle);
 273        input_unregister_handle(handle);
 274        kfree(handle);
 275}
 276
 277static 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
 311static 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
 320int __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
 344void __exit rfkill_handler_exit(void)
 345{
 346        input_unregister_handler(&rfkill_handler);
 347        cancel_delayed_work_sync(&rfkill_op_work);
 348}
 349