pcap_keys.c

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/*
 *  Input driver for PCAP events:
 *   * Power key
 *   * Headphone button
 *
 *  Copyright (c) 2008,2009 Ilya Petrov <[email protected]>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 *
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/input.h>
#include <linux/mfd/ezx-pcap.h>
#include <linux/slab.h>

struct pcap_keys {
    struct pcap_chip *pcap;
    struct input_dev *input;
};

/* PCAP2 interrupts us on keypress */
static irqreturn_t pcap_keys_handler(int irq, void *_pcap_keys)
{
    struct pcap_keys *pcap_keys = _pcap_keys;
    int pirq = irq_to_pcap(pcap_keys->pcap, irq);
    u32 pstat;

    ezx_pcap_read(pcap_keys->pcap, PCAP_REG_PSTAT, &pstat);
    pstat &= 1 << pirq;

    switch (pirq) {
    case PCAP_IRQ_ONOFF:
        input_report_key(pcap_keys->input, KEY_POWER, !pstat);
        break;
    case PCAP_IRQ_MIC:
        input_report_key(pcap_keys->input, KEY_HP, !pstat);
        break;
    }

    input_sync(pcap_keys->input);

    return IRQ_HANDLED;
}

static int __devinit pcap_keys_probe(struct platform_device *pdev)
{
    int err = -ENOMEM;
    struct pcap_keys *pcap_keys;
    struct input_dev *input_dev;

    pcap_keys = kmalloc(sizeof(struct pcap_keys), GFP_KERNEL);
    if (!pcap_keys)
        return err;

    pcap_keys->pcap = dev_get_drvdata(pdev->dev.parent);

    input_dev = input_allocate_device();
    if (!input_dev)
        goto fail;

    pcap_keys->input = input_dev;

    platform_set_drvdata(pdev, pcap_keys);
    input_dev->name = pdev->name;
    input_dev->phys = "pcap-keys/input0";
    input_dev->id.bustype = BUS_HOST;
    input_dev->dev.parent = &pdev->dev;

    __set_bit(EV_KEY, input_dev->evbit);
    __set_bit(KEY_POWER, input_dev->keybit);
    __set_bit(KEY_HP, input_dev->keybit);

    err = input_register_device(input_dev);
    if (err)
        goto fail_allocate;

    err = request_irq(pcap_to_irq(pcap_keys->pcap, PCAP_IRQ_ONOFF),
            pcap_keys_handler, 0, "Power key", pcap_keys);
    if (err)
        goto fail_register;

    err = request_irq(pcap_to_irq(pcap_keys->pcap, PCAP_IRQ_MIC),
            pcap_keys_handler, 0, "Headphone button", pcap_keys);
    if (err)
        goto fail_pwrkey;

    return 0;

fail_pwrkey:
    free_irq(pcap_to_irq(pcap_keys->pcap, PCAP_IRQ_ONOFF), pcap_keys);
fail_register:
    input_unregister_device(input_dev);
    goto fail;
fail_allocate:
    input_free_device(input_dev);
fail:
    kfree(pcap_keys);
    return err;
}

static int __devexit pcap_keys_remove(struct platform_device *pdev)
{
    struct pcap_keys *pcap_keys = platform_get_drvdata(pdev);

    free_irq(pcap_to_irq(pcap_keys->pcap, PCAP_IRQ_ONOFF), pcap_keys);
    free_irq(pcap_to_irq(pcap_keys->pcap, PCAP_IRQ_MIC), pcap_keys);

    input_unregister_device(pcap_keys->input);
    kfree(pcap_keys);

    return 0;
}

static struct platform_driver pcap_keys_device_driver = {
    .probe      = pcap_keys_probe,
    .remove     = __devexit_p(pcap_keys_remove),
    .driver     = {
        .name   = "pcap-keys",
        .owner  = THIS_MODULE,
    }
};
module_platform_driver(pcap_keys_device_driver);

MODULE_DESCRIPTION("Motorola PCAP2 input events driver");
MODULE_AUTHOR("Ilya Petrov <[email protected]>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:pcap_keys");