kernel/drivers/input/misc/pcap_keys.c

   1 /*
   2  *  Input driver for PCAP events:
   3  *   * Power key
   4  *   * Headphone button
   5  *
   6  *  Copyright (c) 2008,2009 Ilya Petrov <ilya.muromec@gmail.com>
   7  *
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU General Public License version 2 as
  10  *  published by the Free Software Foundation.
  11  *
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/input.h>
  18 #include <linux/mfd/ezx-pcap.h>
  19 #include <linux/slab.h>
  20
  21 struct pcap_keys {
  22         struct pcap_chip *pcap;
  23         struct input_dev *input;
  24 };
  25
  26 /* PCAP2 interrupts us on keypress */
  27 static irqreturn_t pcap_keys_handler(int irq, void *_pcap_keys)
  28 {
  29         struct pcap_keys *pcap_keys = _pcap_keys;
  30         int pirq = irq_to_pcap(pcap_keys->pcap, irq);
  31         u32 pstat;
  32
  33         ezx_pcap_read(pcap_keys->pcap, PCAP_REG_PSTAT, &pstat);
  34         pstat &= 1 << pirq;
  35
  36         switch (pirq) {
  37         case PCAP_IRQ_ONOFF:
  38                 input_report_key(pcap_keys->input, KEY_POWER, !pstat);
  39                 break;
  40         case PCAP_IRQ_MIC:
  41                 input_report_key(pcap_keys->input, KEY_HP, !pstat);
  42                 break;
  43         }
  44
  45         input_sync(pcap_keys->input);
  46
  47         return IRQ_HANDLED;
  48 }
  49
  50 static int pcap_keys_probe(struct platform_device *pdev)
  51 {
  52         int err = -ENOMEM;
  53         struct pcap_keys *pcap_keys;
  54         struct input_dev *input_dev;
  55
  56         pcap_keys = kmalloc(sizeof(struct pcap_keys), GFP_KERNEL);
  57         if (!pcap_keys)
  58                 return err;
  59
  60         pcap_keys->pcap = dev_get_drvdata(pdev->dev.parent);
  61
  62         input_dev = input_allocate_device();
  63         if (!input_dev)
  64                 goto fail;
  65
  66         pcap_keys->input = input_dev;
  67
  68         platform_set_drvdata(pdev, pcap_keys);
  69         input_dev->name = pdev->name;
  70         input_dev->phys = "pcap-keys/input0";
  71         input_dev->id.bustype = BUS_HOST;
  72         input_dev->dev.parent = &pdev->dev;
  73
  74         __set_bit(EV_KEY, input_dev->evbit);
  75         __set_bit(KEY_POWER, input_dev->keybit);
  76         __set_bit(KEY_HP, input_dev->keybit);
  77
  78         err = input_register_device(input_dev);
  79         if (err)
  80                 goto fail_allocate;
  81
  82         err = request_irq(pcap_to_irq(pcap_keys->pcap, PCAP_IRQ_ONOFF),
  83                         pcap_keys_handler, 0, "Power key", pcap_keys);
  84         if (err)
  85                 goto fail_register;
  86
  87         err = request_irq(pcap_to_irq(pcap_keys->pcap, PCAP_IRQ_MIC),
  88                         pcap_keys_handler, 0, "Headphone button", pcap_keys);
  89         if (err)
  90                 goto fail_pwrkey;
  91
  92         return 0;
  93
  94 fail_pwrkey:
  95         free_irq(pcap_to_irq(pcap_keys->pcap, PCAP_IRQ_ONOFF), pcap_keys);
  96 fail_register:
  97         input_unregister_device(input_dev);
  98         goto fail;
  99 fail_allocate:
 100         input_free_device(input_dev);
 101 fail:
 102         kfree(pcap_keys);
 103         return err;
 104 }
 105
 106 static int pcap_keys_remove(struct platform_device *pdev)
 107 {
 108         struct pcap_keys *pcap_keys = platform_get_drvdata(pdev);
 109
 110         free_irq(pcap_to_irq(pcap_keys->pcap, PCAP_IRQ_ONOFF), pcap_keys);
 111         free_irq(pcap_to_irq(pcap_keys->pcap, PCAP_IRQ_MIC), pcap_keys);
 112
 113         input_unregister_device(pcap_keys->input);
 114         kfree(pcap_keys);
 115
 116         return 0;
 117 }
 118
 119 static struct platform_driver pcap_keys_device_driver = {
 120         .probe          = pcap_keys_probe,
 121         .remove         = pcap_keys_remove,
 122         .driver         = {
 123                 .name   = "pcap-keys",
 124         }
 125 };
 126 module_platform_driver(pcap_keys_device_driver);
 127
 128 MODULE_DESCRIPTION("Motorola PCAP2 input events driver");
 129 MODULE_AUTHOR("Ilya Petrov <ilya.muromec@gmail.com>");
 130 MODULE_LICENSE("GPL");
 131 MODULE_ALIAS("platform:pcap_keys");