drivers/input/misc/pcap_keys.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  Input driver for PCAP events:
   4  *   * Power key
   5  *   * Headphone button
   6  *
   7  *  Copyright (c) 2008,2009 Ilya Petrov <ilya.muromec@gmail.com>
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/input.h>
  14 #include <linux/mfd/ezx-pcap.h>
  15 #include <linux/slab.h>
  16
  17 struct pcap_keys {
  18         struct pcap_chip *pcap;
  19         struct input_dev *input;
  20 };
  21
  22 /* PCAP2 interrupts us on keypress */
  23 static irqreturn_t pcap_keys_handler(int irq, void *_pcap_keys)
  24 {
  25         struct pcap_keys *pcap_keys = _pcap_keys;
  26         int pirq = irq_to_pcap(pcap_keys->pcap, irq);
  27         u32 pstat;
  28
  29         ezx_pcap_read(pcap_keys->pcap, PCAP_REG_PSTAT, &pstat);
  30         pstat &= 1 << pirq;
  31
  32         switch (pirq) {
  33         case PCAP_IRQ_ONOFF:
  34                 input_report_key(pcap_keys->input, KEY_POWER, !pstat);
  35                 break;
  36         case PCAP_IRQ_MIC:
  37                 input_report_key(pcap_keys->input, KEY_HP, !pstat);
  38                 break;
  39         }
  40
  41         input_sync(pcap_keys->input);
  42
  43         return IRQ_HANDLED;
  44 }
  45
  46 static int pcap_keys_probe(struct platform_device *pdev)
  47 {
  48         int err = -ENOMEM;
  49         struct pcap_keys *pcap_keys;
  50         struct input_dev *input_dev;
  51
  52         pcap_keys = kmalloc(sizeof(struct pcap_keys), GFP_KERNEL);
  53         if (!pcap_keys)
  54                 return err;
  55
  56         pcap_keys->pcap = dev_get_drvdata(pdev->dev.parent);
  57
  58         input_dev = input_allocate_device();
  59         if (!input_dev)
  60                 goto fail;
  61
  62         pcap_keys->input = input_dev;
  63
  64         platform_set_drvdata(pdev, pcap_keys);
  65         input_dev->name = pdev->name;
  66         input_dev->phys = "pcap-keys/input0";
  67         input_dev->id.bustype = BUS_HOST;
  68         input_dev->dev.parent = &pdev->dev;
  69
  70         __set_bit(EV_KEY, input_dev->evbit);
  71         __set_bit(KEY_POWER, input_dev->keybit);
  72         __set_bit(KEY_HP, input_dev->keybit);
  73
  74         err = input_register_device(input_dev);
  75         if (err)
  76                 goto fail_allocate;
  77
  78         err = request_irq(pcap_to_irq(pcap_keys->pcap, PCAP_IRQ_ONOFF),
  79                         pcap_keys_handler, 0, "Power key", pcap_keys);
  80         if (err)
  81                 goto fail_register;
  82
  83         err = request_irq(pcap_to_irq(pcap_keys->pcap, PCAP_IRQ_MIC),
  84                         pcap_keys_handler, 0, "Headphone button", pcap_keys);
  85         if (err)
  86                 goto fail_pwrkey;
  87
  88         return 0;
  89
  90 fail_pwrkey:
  91         free_irq(pcap_to_irq(pcap_keys->pcap, PCAP_IRQ_ONOFF), pcap_keys);
  92 fail_register:
  93         input_unregister_device(input_dev);
  94         goto fail;
  95 fail_allocate:
  96         input_free_device(input_dev);
  97 fail:
  98         kfree(pcap_keys);
  99         return err;
 100 }
 101
 102 static int pcap_keys_remove(struct platform_device *pdev)
 103 {
 104         struct pcap_keys *pcap_keys = platform_get_drvdata(pdev);
 105
 106         free_irq(pcap_to_irq(pcap_keys->pcap, PCAP_IRQ_ONOFF), pcap_keys);
 107         free_irq(pcap_to_irq(pcap_keys->pcap, PCAP_IRQ_MIC), pcap_keys);
 108
 109         input_unregister_device(pcap_keys->input);
 110         kfree(pcap_keys);
 111
 112         return 0;
 113 }
 114
 115 static struct platform_driver pcap_keys_device_driver = {
 116         .probe          = pcap_keys_probe,
 117         .remove         = pcap_keys_remove,
 118         .driver         = {
 119                 .name   = "pcap-keys",
 120         }
 121 };
 122 module_platform_driver(pcap_keys_device_driver);
 123
 124 MODULE_DESCRIPTION("Motorola PCAP2 input events driver");
 125 MODULE_AUTHOR("Ilya Petrov <ilya.muromec@gmail.com>");
 126 MODULE_LICENSE("GPL");
 127 MODULE_ALIAS("platform:pcap_keys");