da9052_onkey.c

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/*
 * ON pin driver for Dialog DA9052 PMICs
 *
 * Copyright(c) 2012 Dialog Semiconductor Ltd.
 *
 * Author: David Dajun Chen <[email protected]>
 *
 * This program is free software; you can redistribute  it and/or modify it
 * under  the terms of  the GNU General  Public License as published by the
 * Free Software Foundation;  either version 2 of the  License, or (at your
 * option) any later version.
 */

#include <linux/init.h>
#include <linux/input.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/workqueue.h>

#include <linux/mfd/da9052/da9052.h>
#include <linux/mfd/da9052/reg.h>

struct da9052_onkey {
    struct da9052 *da9052;
    struct input_dev *input;
    struct delayed_work work;
    unsigned int irq;
};

static void da9052_onkey_query(struct da9052_onkey *onkey)
{
    int key_stat;

    key_stat = da9052_reg_read(onkey->da9052, DA9052_EVENT_B_REG);
    if (key_stat < 0) {
        dev_err(onkey->da9052->dev,
            "Failed to read onkey event %d\n", key_stat);
    } else {
        /*
         * Since interrupt for deassertion of ONKEY pin is not
         * generated, onkey event state determines the onkey
         * button state.
         */
        key_stat &= DA9052_EVENTB_ENONKEY;
        input_report_key(onkey->input, KEY_POWER, key_stat);
        input_sync(onkey->input);
    }

    /*
     * Interrupt is generated only when the ONKEY pin is asserted.
     * Hence the deassertion of the pin is simulated through work queue.
     */
    if (key_stat)
        schedule_delayed_work(&onkey->work, msecs_to_jiffies(50));
}

static void da9052_onkey_work(struct work_struct *work)
{
    struct da9052_onkey *onkey = container_of(work, struct da9052_onkey,
                          work.work);

    da9052_onkey_query(onkey);
}

static irqreturn_t da9052_onkey_irq(int irq, void *data)
{
    struct da9052_onkey *onkey = data;

    da9052_onkey_query(onkey);

    return IRQ_HANDLED;
}

static int __devinit da9052_onkey_probe(struct platform_device *pdev)
{
    struct da9052 *da9052 = dev_get_drvdata(pdev->dev.parent);
    struct da9052_onkey *onkey;
    struct input_dev *input_dev;
    int irq;
    int error;

    if (!da9052) {
        dev_err(&pdev->dev, "Failed to get the driver's data\n");
        return -EINVAL;
    }

    irq = platform_get_irq_byname(pdev, "ONKEY");
    if (irq < 0) {
        dev_err(&pdev->dev,
            "Failed to get an IRQ for input device, %d\n", irq);
        return -EINVAL;
    }

    onkey = kzalloc(sizeof(*onkey), GFP_KERNEL);
    input_dev = input_allocate_device();
    if (!onkey || !input_dev) {
        dev_err(&pdev->dev, "Failed to allocate memory\n");
        error = -ENOMEM;
        goto err_free_mem;
    }

    onkey->input = input_dev;
    onkey->da9052 = da9052;
    onkey->irq = irq;
    INIT_DELAYED_WORK(&onkey->work, da9052_onkey_work);

    input_dev->name = "da9052-onkey";
    input_dev->phys = "da9052-onkey/input0";
    input_dev->dev.parent = &pdev->dev;

    input_dev->evbit[0] = BIT_MASK(EV_KEY);
    __set_bit(KEY_POWER, input_dev->keybit);

    error = request_threaded_irq(onkey->irq, NULL, da9052_onkey_irq,
                     IRQF_TRIGGER_LOW | IRQF_ONESHOT,
                     "ONKEY", onkey);
    if (error < 0) {
        dev_err(onkey->da9052->dev,
            "Failed to register ONKEY IRQ %d, error = %d\n",
            onkey->irq, error);
        goto err_free_mem;
    }

    error = input_register_device(onkey->input);
    if (error) {
        dev_err(&pdev->dev, "Unable to register input device, %d\n",
            error);
        goto err_free_irq;
    }

    platform_set_drvdata(pdev, onkey);
    return 0;

err_free_irq:
    free_irq(onkey->irq, onkey);
    cancel_delayed_work_sync(&onkey->work);
err_free_mem:
    input_free_device(input_dev);
    kfree(onkey);

    return error;
}

static int __devexit da9052_onkey_remove(struct platform_device *pdev)
{
    struct da9052_onkey *onkey = platform_get_drvdata(pdev);

    free_irq(onkey->irq, onkey);
    cancel_delayed_work_sync(&onkey->work);

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

    return 0;
}

static struct platform_driver da9052_onkey_driver = {
    .probe  = da9052_onkey_probe,
    .remove = __devexit_p(da9052_onkey_remove),
    .driver = {
        .name   = "da9052-onkey",
        .owner  = THIS_MODULE,
    },
};
module_platform_driver(da9052_onkey_driver);

MODULE_AUTHOR("David Dajun Chen <[email protected]>");
MODULE_DESCRIPTION("Onkey driver for DA9052");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:da9052-onkey");