net/rfkill/rfkill-input.c

   1 /*
   2  * Input layer to RF Kill interface connector
   3  *
   4  * Copyright (c) 2007 Dmitry Torokhov
   5  */
   6
   7 /*
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License version 2 as published
  10  * by the Free Software Foundation.
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/input.h>
  15 #include <linux/slab.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-input.h"
  22
  23 MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
  24 MODULE_DESCRIPTION("Input layer to RF switch connector");
  25 MODULE_LICENSE("GPL");
  26
  27 struct rfkill_task {
  28         struct work_struct work;
  29         enum rfkill_type type;
  30         struct mutex mutex; /* ensures that task is serialized */
  31         spinlock_t lock; /* for accessing last and desired state */
  32         unsigned long last; /* last schedule */
  33         enum rfkill_state desired_state; /* on/off */
  34 };
  35
  36 static void rfkill_task_handler(struct work_struct *work)
  37 {
  38         struct rfkill_task *task = container_of(work, struct rfkill_task, work);
  39
  40         mutex_lock(&task->mutex);
  41
  42         rfkill_switch_all(task->type, task->desired_state);
  43
  44         mutex_unlock(&task->mutex);
  45 }
  46
  47 static void rfkill_task_epo_handler(struct work_struct *work)
  48 {
  49         rfkill_epo();
  50 }
  51
  52 static DECLARE_WORK(epo_work, rfkill_task_epo_handler);
  53
  54 static void rfkill_schedule_epo(void)
  55 {
  56         schedule_work(&epo_work);
  57 }
  58
  59 static void rfkill_schedule_set(struct rfkill_task *task,
  60                                 enum rfkill_state desired_state)
  61 {
  62         unsigned long flags;
  63
  64         if (unlikely(work_pending(&epo_work)))
  65                 return;
  66
  67         spin_lock_irqsave(&task->lock, flags);
  68
  69         if (time_after(jiffies, task->last + msecs_to_jiffies(200))) {
  70                 task->desired_state = desired_state;
  71                 task->last = jiffies;
  72                 schedule_work(&task->work);
  73         }
  74
  75         spin_unlock_irqrestore(&task->lock, flags);
  76 }
  77
  78 static void rfkill_schedule_toggle(struct rfkill_task *task)
  79 {
  80         unsigned long flags;
  81
  82         if (unlikely(work_pending(&epo_work)))
  83                 return;
  84
  85         spin_lock_irqsave(&task->lock, flags);
  86
  87         if (time_after(jiffies, task->last + msecs_to_jiffies(200))) {
  88                 task->desired_state =
  89                                 rfkill_state_complement(task->desired_state);
  90                 task->last = jiffies;
  91                 schedule_work(&task->work);
  92         }
  93
  94         spin_unlock_irqrestore(&task->lock, flags);
  95 }
  96
  97 #define DEFINE_RFKILL_TASK(n, t)                                \
  98         struct rfkill_task n = {                                \
  99                 .work = __WORK_INITIALIZER(n.work,              \
 100                                 rfkill_task_handler),           \
 101                 .type = t,                                      \
 102                 .mutex = __MUTEX_INITIALIZER(n.mutex),          \
 103                 .lock = __SPIN_LOCK_UNLOCKED(n.lock),           \
 104                 .desired_state = RFKILL_STATE_UNBLOCKED,        \
 105         }
 106
 107 static DEFINE_RFKILL_TASK(rfkill_wlan, RFKILL_TYPE_WLAN);
 108 static DEFINE_RFKILL_TASK(rfkill_bt, RFKILL_TYPE_BLUETOOTH);
 109 static DEFINE_RFKILL_TASK(rfkill_uwb, RFKILL_TYPE_UWB);
 110 static DEFINE_RFKILL_TASK(rfkill_wimax, RFKILL_TYPE_WIMAX);
 111 static DEFINE_RFKILL_TASK(rfkill_wwan, RFKILL_TYPE_WWAN);
 112
 113 static void rfkill_schedule_evsw_rfkillall(int state)
 114 {
 115         /* EVERY radio type. state != 0 means radios ON */
 116         /* handle EPO (emergency power off) through shortcut */
 117         if (state) {
 118                 rfkill_schedule_set(&rfkill_wwan,
 119                                     RFKILL_STATE_UNBLOCKED);
 120                 rfkill_schedule_set(&rfkill_wimax,
 121                                     RFKILL_STATE_UNBLOCKED);
 122                 rfkill_schedule_set(&rfkill_uwb,
 123                                     RFKILL_STATE_UNBLOCKED);
 124                 rfkill_schedule_set(&rfkill_bt,
 125                                     RFKILL_STATE_UNBLOCKED);
 126                 rfkill_schedule_set(&rfkill_wlan,
 127                                     RFKILL_STATE_UNBLOCKED);
 128         } else
 129                 rfkill_schedule_epo();
 130 }
 131
 132 static void rfkill_event(struct input_handle *handle, unsigned int type,
 133                         unsigned int code, int data)
 134 {
 135         if (type == EV_KEY && data == 1) {
 136                 switch (code) {
 137                 case KEY_WLAN:
 138                         rfkill_schedule_toggle(&rfkill_wlan);
 139                         break;
 140                 case KEY_BLUETOOTH:
 141                         rfkill_schedule_toggle(&rfkill_bt);
 142                         break;
 143                 case KEY_UWB:
 144                         rfkill_schedule_toggle(&rfkill_uwb);
 145                         break;
 146                 case KEY_WIMAX:
 147                         rfkill_schedule_toggle(&rfkill_wimax);
 148                         break;
 149                 default:
 150                         break;
 151                 }
 152         } else if (type == EV_SW) {
 153                 switch (code) {
 154                 case SW_RFKILL_ALL:
 155                         rfkill_schedule_evsw_rfkillall(data);
 156                         break;
 157                 default:
 158                         break;
 159                 }
 160         }
 161 }
 162
 163 static int rfkill_connect(struct input_handler *handler, struct input_dev *dev,
 164                           const struct input_device_id *id)
 165 {
 166         struct input_handle *handle;
 167         int error;
 168
 169         handle = kzalloc(sizeof(struct input_handle), GFP_KERNEL);
 170         if (!handle)
 171                 return -ENOMEM;
 172
 173         handle->dev = dev;
 174         handle->handler = handler;
 175         handle->name = "rfkill";
 176
 177         /* causes rfkill_start() to be called */
 178         error = input_register_handle(handle);
 179         if (error)
 180                 goto err_free_handle;
 181
 182         error = input_open_device(handle);
 183         if (error)
 184                 goto err_unregister_handle;
 185
 186         return 0;
 187
 188  err_unregister_handle:
 189         input_unregister_handle(handle);
 190  err_free_handle:
 191         kfree(handle);
 192         return error;
 193 }
 194
 195 static void rfkill_start(struct input_handle *handle)
 196 {
 197         /* Take event_lock to guard against configuration changes, we
 198          * should be able to deal with concurrency with rfkill_event()
 199          * just fine (which event_lock will also avoid). */
 200         spin_lock_irq(&handle->dev->event_lock);
 201
 202         if (test_bit(EV_SW, handle->dev->evbit)) {
 203                 if (test_bit(SW_RFKILL_ALL, handle->dev->swbit))
 204                         rfkill_schedule_evsw_rfkillall(test_bit(SW_RFKILL_ALL,
 205                                                         handle->dev->sw));
 206                 /* add resync for further EV_SW events here */
 207         }
 208
 209         spin_unlock_irq(&handle->dev->event_lock);
 210 }
 211
 212 static void rfkill_disconnect(struct input_handle *handle)
 213 {
 214         input_close_device(handle);
 215         input_unregister_handle(handle);
 216         kfree(handle);
 217 }
 218
 219 static const struct input_device_id rfkill_ids[] = {
 220         {
 221                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 222                 .evbit = { BIT_MASK(EV_KEY) },
 223                 .keybit = { [BIT_WORD(KEY_WLAN)] = BIT_MASK(KEY_WLAN) },
 224         },
 225         {
 226                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 227                 .evbit = { BIT_MASK(EV_KEY) },
 228                 .keybit = { [BIT_WORD(KEY_BLUETOOTH)] = BIT_MASK(KEY_BLUETOOTH) },
 229         },
 230         {
 231                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 232                 .evbit = { BIT_MASK(EV_KEY) },
 233                 .keybit = { [BIT_WORD(KEY_UWB)] = BIT_MASK(KEY_UWB) },
 234         },
 235         {
 236                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 237                 .evbit = { BIT_MASK(EV_KEY) },
 238                 .keybit = { [BIT_WORD(KEY_WIMAX)] = BIT_MASK(KEY_WIMAX) },
 239         },
 240         {
 241                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_SWBIT,
 242                 .evbit = { BIT(EV_SW) },
 243                 .swbit = { [BIT_WORD(SW_RFKILL_ALL)] = BIT_MASK(SW_RFKILL_ALL) },
 244         },
 245         { }
 246 };
 247
 248 static struct input_handler rfkill_handler = {
 249         .event =        rfkill_event,
 250         .connect =      rfkill_connect,
 251         .disconnect =   rfkill_disconnect,
 252         .start =        rfkill_start,
 253         .name =         "rfkill",
 254         .id_table =     rfkill_ids,
 255 };
 256
 257 static int __init rfkill_handler_init(void)
 258 {
 259         return input_register_handler(&rfkill_handler);
 260 }
 261
 262 static void __exit rfkill_handler_exit(void)
 263 {
 264         input_unregister_handler(&rfkill_handler);
 265         flush_scheduled_work();
 266 }
 267
 268 module_init(rfkill_handler_init);
 269 module_exit(rfkill_handler_exit);