linux/net/rfkill/input.c
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   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
  23enum 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
  33static enum rfkill_input_master_mode rfkill_master_switch_mode =
  34                                        RFKILL_INPUT_MASTER_UNBLOCKALL;
  35module_param_named(master_switch_mode, rfkill_master_switch_mode, uint, 0);
  36MODULE_PARM_DESC(master_switch_mode,
  37        "SW_RFKILL_ALL ON should: 0=do nothing (only unlock); 1=restore; 2=unblock all");
  38
  39static DEFINE_SPINLOCK(rfkill_op_lock);
  40static bool rfkill_op_pending;
  41static unsigned long rfkill_sw_pending[BITS_TO_LONGS(NUM_RFKILL_TYPES)];
  42static unsigned long rfkill_sw_state[BITS_TO_LONGS(NUM_RFKILL_TYPES)];
  43
  44enum 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
  51static enum rfkill_sched_op rfkill_master_switch_op;
  52static enum rfkill_sched_op rfkill_op;
  53
  54static 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
  82static 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
  94static 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
 137static DECLARE_DELAYED_WORK(rfkill_op_work, rfkill_op_handler);
 138static unsigned long rfkill_last_scheduled;
 139
 140static 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
 146static 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
 153static 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
 169static 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
 185static 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
 193static 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
 218static 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
 250static 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
 267static void rfkill_disconnect(struct input_handle *handle)
 268{
 269        input_close_device(handle);
 270        input_unregister_handle(handle);
 271        kfree(handle);
 272}
 273
 274static 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
 308static 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
 317int __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
 339void __exit rfkill_handler_exit(void)
 340{
 341        input_unregister_handler(&rfkill_handler);
 342        cancel_delayed_work_sync(&rfkill_op_work);
 343}
 344