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         enum rfkill_state current_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         enum rfkill_state state;
  40
  41         mutex_lock(&task->mutex);
  42
  43         /*
  44          * Use temp variable to fetch desired state to keep it
  45          * consistent even if rfkill_schedule_toggle() runs in
  46          * another thread or interrupts us.
  47          */
  48         state = task->desired_state;
  49
  50         if (state != task->current_state) {
  51                 rfkill_switch_all(task->type, state);
  52                 task->current_state = state;
  53         }
  54
  55         mutex_unlock(&task->mutex);
  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         spin_lock_irqsave(&task->lock, flags);
  64
  65         if (time_after(jiffies, task->last + msecs_to_jiffies(200))) {
  66                 task->desired_state = desired_state;
  67                 task->last = jiffies;
  68                 schedule_work(&task->work);
  69         }
  70
  71         spin_unlock_irqrestore(&task->lock, flags);
  72 }
  73
  74 static void rfkill_schedule_toggle(struct rfkill_task *task)
  75 {
  76         unsigned long flags;
  77
  78         spin_lock_irqsave(&task->lock, flags);
  79
  80         if (time_after(jiffies, task->last + msecs_to_jiffies(200))) {
  81                 task->desired_state = !task->desired_state;
  82                 task->last = jiffies;
  83                 schedule_work(&task->work);
  84         }
  85
  86         spin_unlock_irqrestore(&task->lock, flags);
  87 }
  88
  89 #define DEFINE_RFKILL_TASK(n, t)                        \
  90         struct rfkill_task n = {                        \
  91                 .work = __WORK_INITIALIZER(n.work,      \
  92                                 rfkill_task_handler),   \
  93                 .type = t,                              \
  94                 .mutex = __MUTEX_INITIALIZER(n.mutex),  \
  95                 .lock = __SPIN_LOCK_UNLOCKED(n.lock),   \
  96                 .desired_state = RFKILL_STATE_ON,       \
  97                 .current_state = RFKILL_STATE_ON,       \
  98         }
  99
 100 static DEFINE_RFKILL_TASK(rfkill_wlan, RFKILL_TYPE_WLAN);
 101 static DEFINE_RFKILL_TASK(rfkill_bt, RFKILL_TYPE_BLUETOOTH);
 102 static DEFINE_RFKILL_TASK(rfkill_uwb, RFKILL_TYPE_UWB);
 103 static DEFINE_RFKILL_TASK(rfkill_wimax, RFKILL_TYPE_WIMAX);
 104
 105 static void rfkill_event(struct input_handle *handle, unsigned int type,
 106                         unsigned int code, int data)
 107 {
 108         if (type == EV_KEY && data == 1) {
 109                 switch (code) {
 110                 case KEY_WLAN:
 111                         rfkill_schedule_toggle(&rfkill_wlan);
 112                         break;
 113                 case KEY_BLUETOOTH:
 114                         rfkill_schedule_toggle(&rfkill_bt);
 115                         break;
 116                 case KEY_UWB:
 117                         rfkill_schedule_toggle(&rfkill_uwb);
 118                         break;
 119                 case KEY_WIMAX:
 120                         rfkill_schedule_toggle(&rfkill_wimax);
 121                         break;
 122                 default:
 123                         break;
 124                 }
 125         } else if (type == EV_SW) {
 126                 switch (code) {
 127                 case SW_RFKILL_ALL:
 128                         /* EVERY radio type. data != 0 means radios ON */
 129                         rfkill_schedule_set(&rfkill_wimax,
 130                                             (data)? RFKILL_STATE_ON:
 131                                                     RFKILL_STATE_OFF);
 132                         rfkill_schedule_set(&rfkill_uwb,
 133                                             (data)? RFKILL_STATE_ON:
 134                                                     RFKILL_STATE_OFF);
 135                         rfkill_schedule_set(&rfkill_bt,
 136                                             (data)? RFKILL_STATE_ON:
 137                                                     RFKILL_STATE_OFF);
 138                         rfkill_schedule_set(&rfkill_wlan,
 139                                             (data)? RFKILL_STATE_ON:
 140                                                     RFKILL_STATE_OFF);
 141                         break;
 142                 default:
 143                         break;
 144                 }
 145         }
 146 }
 147
 148 static int rfkill_connect(struct input_handler *handler, struct input_dev *dev,
 149                           const struct input_device_id *id)
 150 {
 151         struct input_handle *handle;
 152         int error;
 153
 154         handle = kzalloc(sizeof(struct input_handle), GFP_KERNEL);
 155         if (!handle)
 156                 return -ENOMEM;
 157
 158         handle->dev = dev;
 159         handle->handler = handler;
 160         handle->name = "rfkill";
 161
 162         error = input_register_handle(handle);
 163         if (error)
 164                 goto err_free_handle;
 165
 166         error = input_open_device(handle);
 167         if (error)
 168                 goto err_unregister_handle;
 169
 170         return 0;
 171
 172  err_unregister_handle:
 173         input_unregister_handle(handle);
 174  err_free_handle:
 175         kfree(handle);
 176         return error;
 177 }
 178
 179 static void rfkill_disconnect(struct input_handle *handle)
 180 {
 181         input_close_device(handle);
 182         input_unregister_handle(handle);
 183         kfree(handle);
 184 }
 185
 186 static const struct input_device_id rfkill_ids[] = {
 187         {
 188                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 189                 .evbit = { BIT_MASK(EV_KEY) },
 190                 .keybit = { [BIT_WORD(KEY_WLAN)] = BIT_MASK(KEY_WLAN) },
 191         },
 192         {
 193                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 194                 .evbit = { BIT_MASK(EV_KEY) },
 195                 .keybit = { [BIT_WORD(KEY_BLUETOOTH)] = BIT_MASK(KEY_BLUETOOTH) },
 196         },
 197         {
 198                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 199                 .evbit = { BIT_MASK(EV_KEY) },
 200                 .keybit = { [BIT_WORD(KEY_UWB)] = BIT_MASK(KEY_UWB) },
 201         },
 202         {
 203                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 204                 .evbit = { BIT_MASK(EV_KEY) },
 205                 .keybit = { [BIT_WORD(KEY_WIMAX)] = BIT_MASK(KEY_WIMAX) },
 206         },
 207         {
 208                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_SWBIT,
 209                 .evbit = { BIT(EV_SW) },
 210                 .swbit = { [BIT_WORD(SW_RFKILL_ALL)] = BIT_MASK(SW_RFKILL_ALL) },
 211         },
 212         { }
 213 };
 214
 215 static struct input_handler rfkill_handler = {
 216         .event =        rfkill_event,
 217         .connect =      rfkill_connect,
 218         .disconnect =   rfkill_disconnect,
 219         .name =         "rfkill",
 220         .id_table =     rfkill_ids,
 221 };
 222
 223 static int __init rfkill_handler_init(void)
 224 {
 225         return input_register_handler(&rfkill_handler);
 226 }
 227
 228 static void __exit rfkill_handler_exit(void)
 229 {
 230         input_unregister_handler(&rfkill_handler);
 231         flush_scheduled_work();
 232 }
 233
 234 module_init(rfkill_handler_init);
 235 module_exit(rfkill_handler_exit);