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 (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
 158static 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
 175static 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
 191static 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
 199static 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
 224static 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
 256static 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
 273static void rfkill_disconnect(struct input_handle *handle)
 274{
 275        input_close_device(handle);
 276        input_unregister_handle(handle);
 277        kfree(handle);
 278}
 279
 280static 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
 314static 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
 323int __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
 347void __exit rfkill_handler_exit(void)
 348{
 349        input_unregister_handler(&rfkill_handler);
 350        cancel_delayed_work_sync(&rfkill_op_work);
 351}
 352
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