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_toggle(struct rfkill_task *task)
  59 {
  60         unsigned long flags;
  61
  62         spin_lock_irqsave(&task->lock, flags);
  63
  64         if (time_after(jiffies, task->last + msecs_to_jiffies(200))) {
  65                 task->desired_state = !task->desired_state;
  66                 task->last = jiffies;
  67                 schedule_work(&task->work);
  68         }
  69
  70         spin_unlock_irqrestore(&task->lock, flags);
  71 }
  72
  73 #define DEFINE_RFKILL_TASK(n, t)                        \
  74         struct rfkill_task n = {                        \
  75                 .work = __WORK_INITIALIZER(n.work,      \
  76                                 rfkill_task_handler),   \
  77                 .type = t,                              \
  78                 .mutex = __MUTEX_INITIALIZER(n.mutex),  \
  79                 .lock = __SPIN_LOCK_UNLOCKED(n.lock),   \
  80                 .desired_state = RFKILL_STATE_ON,       \
  81                 .current_state = RFKILL_STATE_ON,       \
  82         }
  83
  84 static DEFINE_RFKILL_TASK(rfkill_wlan, RFKILL_TYPE_WLAN);
  85 static DEFINE_RFKILL_TASK(rfkill_bt, RFKILL_TYPE_BLUETOOTH);
  86 static DEFINE_RFKILL_TASK(rfkill_uwb, RFKILL_TYPE_UWB);
  87
  88 static void rfkill_event(struct input_handle *handle, unsigned int type,
  89                         unsigned int code, int down)
  90 {
  91         if (type == EV_KEY && down == 1) {
  92                 switch (code) {
  93                 case KEY_WLAN:
  94                         rfkill_schedule_toggle(&rfkill_wlan);
  95                         break;
  96                 case KEY_BLUETOOTH:
  97                         rfkill_schedule_toggle(&rfkill_bt);
  98                         break;
  99                 case KEY_UWB:
 100                         rfkill_schedule_toggle(&rfkill_uwb);
 101                         break;
 102                 default:
 103                         break;
 104                 }
 105         }
 106 }
 107
 108 static int rfkill_connect(struct input_handler *handler, struct input_dev *dev,
 109                           const struct input_device_id *id)
 110 {
 111         struct input_handle *handle;
 112         int error;
 113
 114         handle = kzalloc(sizeof(struct input_handle), GFP_KERNEL);
 115         if (!handle)
 116                 return -ENOMEM;
 117
 118         handle->dev = dev;
 119         handle->handler = handler;
 120         handle->name = "rfkill";
 121
 122         error = input_register_handle(handle);
 123         if (error)
 124                 goto err_free_handle;
 125
 126         error = input_open_device(handle);
 127         if (error)
 128                 goto err_unregister_handle;
 129
 130         return 0;
 131
 132  err_unregister_handle:
 133         input_unregister_handle(handle);
 134  err_free_handle:
 135         kfree(handle);
 136         return error;
 137 }
 138
 139 static void rfkill_disconnect(struct input_handle *handle)
 140 {
 141         input_close_device(handle);
 142         input_unregister_handle(handle);
 143         kfree(handle);
 144 }
 145
 146 static const struct input_device_id rfkill_ids[] = {
 147         {
 148                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 149                 .evbit = { BIT_MASK(EV_KEY) },
 150                 .keybit = { [BIT_WORD(KEY_WLAN)] = BIT_MASK(KEY_WLAN) },
 151         },
 152         {
 153                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 154                 .evbit = { BIT_MASK(EV_KEY) },
 155                 .keybit = { [BIT_WORD(KEY_BLUETOOTH)] = BIT_MASK(KEY_BLUETOOTH) },
 156         },
 157         {
 158                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 159                 .evbit = { BIT_MASK(EV_KEY) },
 160                 .keybit = { [BIT_WORD(KEY_UWB)] = BIT_MASK(KEY_UWB) },
 161         },
 162         { }
 163 };
 164
 165 static struct input_handler rfkill_handler = {
 166         .event =        rfkill_event,
 167         .connect =      rfkill_connect,
 168         .disconnect =   rfkill_disconnect,
 169         .name =         "rfkill",
 170         .id_table =     rfkill_ids,
 171 };
 172
 173 static int __init rfkill_handler_init(void)
 174 {
 175         return input_register_handler(&rfkill_handler);
 176 }
 177
 178 static void __exit rfkill_handler_exit(void)
 179 {
 180         input_unregister_handler(&rfkill_handler);
 181         flush_scheduled_work();
 182 }
 183
 184 module_init(rfkill_handler_init);
 185 module_exit(rfkill_handler_exit);