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
  20 #include "rfkill-input.h"
  21
  22 MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
  23 MODULE_DESCRIPTION("Input layer to RF switch connector");
  24 MODULE_LICENSE("GPL");
  25
  26 struct rfkill_task {
  27         struct work_struct work;
  28         enum rfkill_type type;
  29         struct mutex mutex; /* ensures that task is serialized */
  30         spinlock_t lock; /* for accessing last and desired state */
  31         unsigned long last; /* last schedule */
  32         enum rfkill_state desired_state; /* on/off */
  33 };
  34
  35 static void rfkill_task_handler(struct work_struct *work)
  36 {
  37         struct rfkill_task *task = container_of(work, struct rfkill_task, work);
  38
  39         mutex_lock(&task->mutex);
  40
  41         rfkill_switch_all(task->type, task->desired_state);
  42
  43         mutex_unlock(&task->mutex);
  44 }
  45
  46 static void rfkill_task_epo_handler(struct work_struct *work)
  47 {
  48         rfkill_epo();
  49 }
  50
  51 static DECLARE_WORK(epo_work, rfkill_task_epo_handler);
  52
  53 static void rfkill_schedule_epo(void)
  54 {
  55         schedule_work(&epo_work);
  56 }
  57
  58 static void rfkill_schedule_set(struct rfkill_task *task,
  59                                 enum rfkill_state desired_state)
  60 {
  61         unsigned long flags;
  62
  63         if (unlikely(work_pending(&epo_work)))
  64                 return;
  65
  66         spin_lock_irqsave(&task->lock, flags);
  67
  68         if (time_after(jiffies, task->last + msecs_to_jiffies(200))) {
  69                 task->desired_state = desired_state;
  70                 task->last = jiffies;
  71                 schedule_work(&task->work);
  72         }
  73
  74         spin_unlock_irqrestore(&task->lock, flags);
  75 }
  76
  77 static void rfkill_schedule_toggle(struct rfkill_task *task)
  78 {
  79         unsigned long flags;
  80
  81         if (unlikely(work_pending(&epo_work)))
  82                 return;
  83
  84         spin_lock_irqsave(&task->lock, flags);
  85
  86         if (time_after(jiffies, task->last + msecs_to_jiffies(200))) {
  87                 task->desired_state =
  88                                 rfkill_state_complement(task->desired_state);
  89                 task->last = jiffies;
  90                 schedule_work(&task->work);
  91         }
  92
  93         spin_unlock_irqrestore(&task->lock, flags);
  94 }
  95
  96 #define DEFINE_RFKILL_TASK(n, t)                                \
  97         struct rfkill_task n = {                                \
  98                 .work = __WORK_INITIALIZER(n.work,              \
  99                                 rfkill_task_handler),           \
 100                 .type = t,                                      \
 101                 .mutex = __MUTEX_INITIALIZER(n.mutex),          \
 102                 .lock = __SPIN_LOCK_UNLOCKED(n.lock),           \
 103                 .desired_state = RFKILL_STATE_UNBLOCKED,        \
 104         }
 105
 106 static DEFINE_RFKILL_TASK(rfkill_wlan, RFKILL_TYPE_WLAN);
 107 static DEFINE_RFKILL_TASK(rfkill_bt, RFKILL_TYPE_BLUETOOTH);
 108 static DEFINE_RFKILL_TASK(rfkill_uwb, RFKILL_TYPE_UWB);
 109 static DEFINE_RFKILL_TASK(rfkill_wimax, RFKILL_TYPE_WIMAX);
 110 static DEFINE_RFKILL_TASK(rfkill_wwan, RFKILL_TYPE_WWAN);
 111
 112 static void rfkill_schedule_evsw_rfkillall(int state)
 113 {
 114         /* EVERY radio type. state != 0 means radios ON */
 115         /* handle EPO (emergency power off) through shortcut */
 116         if (state) {
 117                 rfkill_schedule_set(&rfkill_wwan,
 118                                     RFKILL_STATE_UNBLOCKED);
 119                 rfkill_schedule_set(&rfkill_wimax,
 120                                     RFKILL_STATE_UNBLOCKED);
 121                 rfkill_schedule_set(&rfkill_uwb,
 122                                     RFKILL_STATE_UNBLOCKED);
 123                 rfkill_schedule_set(&rfkill_bt,
 124                                     RFKILL_STATE_UNBLOCKED);
 125                 rfkill_schedule_set(&rfkill_wlan,
 126                                     RFKILL_STATE_UNBLOCKED);
 127         } else
 128                 rfkill_schedule_epo();
 129 }
 130
 131 static void rfkill_event(struct input_handle *handle, unsigned int type,
 132                         unsigned int code, int data)
 133 {
 134         if (type == EV_KEY && data == 1) {
 135                 switch (code) {
 136                 case KEY_WLAN:
 137                         rfkill_schedule_toggle(&rfkill_wlan);
 138                         break;
 139                 case KEY_BLUETOOTH:
 140                         rfkill_schedule_toggle(&rfkill_bt);
 141                         break;
 142                 case KEY_UWB:
 143                         rfkill_schedule_toggle(&rfkill_uwb);
 144                         break;
 145                 case KEY_WIMAX:
 146                         rfkill_schedule_toggle(&rfkill_wimax);
 147                         break;
 148                 default:
 149                         break;
 150                 }
 151         } else if (type == EV_SW) {
 152                 switch (code) {
 153                 case SW_RFKILL_ALL:
 154                         rfkill_schedule_evsw_rfkillall(data);
 155                         break;
 156                 default:
 157                         break;
 158                 }
 159         }
 160 }
 161
 162 static int rfkill_connect(struct input_handler *handler, struct input_dev *dev,
 163                           const struct input_device_id *id)
 164 {
 165         struct input_handle *handle;
 166         int error;
 167
 168         handle = kzalloc(sizeof(struct input_handle), GFP_KERNEL);
 169         if (!handle)
 170                 return -ENOMEM;
 171
 172         handle->dev = dev;
 173         handle->handler = handler;
 174         handle->name = "rfkill";
 175
 176         /* causes rfkill_start() to be called */
 177         error = input_register_handle(handle);
 178         if (error)
 179                 goto err_free_handle;
 180
 181         error = input_open_device(handle);
 182         if (error)
 183                 goto err_unregister_handle;
 184
 185         return 0;
 186
 187  err_unregister_handle:
 188         input_unregister_handle(handle);
 189  err_free_handle:
 190         kfree(handle);
 191         return error;
 192 }
 193
 194 static void rfkill_start(struct input_handle *handle)
 195 {
 196         /* Take event_lock to guard against configuration changes, we
 197          * should be able to deal with concurrency with rfkill_event()
 198          * just fine (which event_lock will also avoid). */
 199         spin_lock_irq(&handle->dev->event_lock);
 200
 201         if (test_bit(EV_SW, handle->dev->evbit)) {
 202                 if (test_bit(SW_RFKILL_ALL, handle->dev->swbit))
 203                         rfkill_schedule_evsw_rfkillall(test_bit(SW_RFKILL_ALL,
 204                                                         handle->dev->sw));
 205                 /* add resync for further EV_SW events here */
 206         }
 207
 208         spin_unlock_irq(&handle->dev->event_lock);
 209 }
 210
 211 static void rfkill_disconnect(struct input_handle *handle)
 212 {
 213         input_close_device(handle);
 214         input_unregister_handle(handle);
 215         kfree(handle);
 216 }
 217
 218 static const struct input_device_id rfkill_ids[] = {
 219         {
 220                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 221                 .evbit = { BIT_MASK(EV_KEY) },
 222                 .keybit = { [BIT_WORD(KEY_WLAN)] = BIT_MASK(KEY_WLAN) },
 223         },
 224         {
 225                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 226                 .evbit = { BIT_MASK(EV_KEY) },
 227                 .keybit = { [BIT_WORD(KEY_BLUETOOTH)] = BIT_MASK(KEY_BLUETOOTH) },
 228         },
 229         {
 230                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 231                 .evbit = { BIT_MASK(EV_KEY) },
 232                 .keybit = { [BIT_WORD(KEY_UWB)] = BIT_MASK(KEY_UWB) },
 233         },
 234         {
 235                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 236                 .evbit = { BIT_MASK(EV_KEY) },
 237                 .keybit = { [BIT_WORD(KEY_WIMAX)] = BIT_MASK(KEY_WIMAX) },
 238         },
 239         {
 240                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_SWBIT,
 241                 .evbit = { BIT(EV_SW) },
 242                 .swbit = { [BIT_WORD(SW_RFKILL_ALL)] = BIT_MASK(SW_RFKILL_ALL) },
 243         },
 244         { }
 245 };
 246
 247 static struct input_handler rfkill_handler = {
 248         .event =        rfkill_event,
 249         .connect =      rfkill_connect,
 250         .disconnect =   rfkill_disconnect,
 251         .start =        rfkill_start,
 252         .name =         "rfkill",
 253         .id_table =     rfkill_ids,
 254 };
 255
 256 static int __init rfkill_handler_init(void)
 257 {
 258         return input_register_handler(&rfkill_handler);
 259 }
 260
 261 static void __exit rfkill_handler_exit(void)
 262 {
 263         input_unregister_handler(&rfkill_handler);
 264         flush_scheduled_work();
 265 }
 266
 267 module_init(rfkill_handler_init);
 268 module_exit(rfkill_handler_exit);