wakeup_button/wakeup_button.c

   1 /*
   2  * wakeup_button.c - Power Button which is pushed on resume from standby.
   3  *
   4  * Copyright (c) 2011 Stefan Seidel
   5  *
   6  * This file is released under the GPLv2 or later.
   7  */
   8 #include <linux/module.h>
   9 #include <linux/init.h>
  10 #include <linux/earlysuspend.h>
  11 #include <linux/input.h>
  12
  13 MODULE_LICENSE("GPL");
  14 MODULE_AUTHOR("Stefan Seidel <android@stefanseidel.info>");
  15 MODULE_DESCRIPTION("Sets up a virtual input device and sends a power key event during early resume. Needed for some to make Android on x86 wake up properly.");
  16
  17 static struct input_dev *input;
  18
  19 static void wakeup_button_early_suspend(struct early_suspend *h)
  20 {
  21         return;
  22 }
  23
  24 static void wakeup_button_early_resume(struct early_suspend *h)
  25 {
  26         printk("Early resume, push virtual power button!\n");
  27         input_report_key(input, KEY_POWER, 1);
  28         input_sync(input);
  29         input_report_key(input, KEY_POWER, 0);
  30         input_sync(input);
  31 }
  32
  33 static struct early_suspend wakeup_button_early_suspend_handlers = {
  34         .level = EARLY_SUSPEND_LEVEL_BLANK_SCREEN - 1, // very late resume
  35         .suspend = wakeup_button_early_suspend,
  36         .resume = wakeup_button_early_resume
  37 };
  38
  39 static int __init wakeup_button_init(void)
  40 {
  41         int error;
  42         printk("Registering Android Wakeup Button.\n");
  43         input = input_allocate_device();
  44         input->name = "Wakeup Button";
  45         input->id.bustype = BUS_USB; // use BUS_USB here so that Android registers this as an external key
  46         input->evbit[0] = BIT_MASK(EV_KEY);
  47         set_bit(KEY_POWER, input->keybit);
  48         error = input_register_device(input);
  49         if (error) {
  50                 input_free_device(input);
  51         } else {
  52                 register_early_suspend(&wakeup_button_early_suspend_handlers);
  53         }
  54         return error;
  55 }
  56
  57 static void __exit wakeup_button_exit(void)
  58 {
  59         printk("Unregistering Android Wakeup Button.\n");
  60         unregister_early_suspend(&wakeup_button_early_suspend_handlers);
  61         input_unregister_device(input);
  62         return;
  63 }
  64
  65 module_init(wakeup_button_init);
  66 module_exit(wakeup_button_exit);