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