twl4030-pwrbutton.c

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#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/i2c/twl.h>

#define PWR_PWRON_IRQ (1 << 0)

#define STS_HW_CONDITIONS 0xf

static irqreturn_t powerbutton_irq(int irq, void *_pwr)
{
    struct input_dev *pwr = _pwr;
    int err;
    u8 value;

    err = twl_i2c_read_u8(TWL4030_MODULE_PM_MASTER, &value,
                STS_HW_CONDITIONS);
    if (!err)  {
        pm_wakeup_event(pwr->dev.parent, 0);
        input_report_key(pwr, KEY_POWER, value & PWR_PWRON_IRQ);
        input_sync(pwr);
    } else {
        dev_err(pwr->dev.parent, "twl4030: i2c error %d while reading"
            " TWL4030 PM_MASTER STS_HW_CONDITIONS register\n", err);
    }

    return IRQ_HANDLED;
}

static int __init twl4030_pwrbutton_probe(struct platform_device *pdev)
{
    struct input_dev *pwr;
    int irq = platform_get_irq(pdev, 0);
    int err;

    pwr = input_allocate_device();
    if (!pwr) {
        dev_dbg(&pdev->dev, "Can't allocate power button\n");
        return -ENOMEM;
    }

    pwr->evbit[0] = BIT_MASK(EV_KEY);
    pwr->keybit[BIT_WORD(KEY_POWER)] = BIT_MASK(KEY_POWER);
    pwr->name = "twl4030_pwrbutton";
    pwr->phys = "twl4030_pwrbutton/input0";
    pwr->dev.parent = &pdev->dev;

    err = request_threaded_irq(irq, NULL, powerbutton_irq,
            IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
            "twl4030_pwrbutton", pwr);
    if (err < 0) {
        dev_dbg(&pdev->dev, "Can't get IRQ for pwrbutton: %d\n", err);
        goto free_input_dev;
    }

    err = input_register_device(pwr);
    if (err) {
        dev_dbg(&pdev->dev, "Can't register power button: %d\n", err);
        goto free_irq;
    }

    platform_set_drvdata(pdev, pwr);

    return 0;

free_irq:
    free_irq(irq, pwr);
free_input_dev:
    input_free_device(pwr);
    return err;
}

static int __exit twl4030_pwrbutton_remove(struct platform_device *pdev)
{
    struct input_dev *pwr = platform_get_drvdata(pdev);
    int irq = platform_get_irq(pdev, 0);

    free_irq(irq, pwr);
    input_unregister_device(pwr);

    return 0;
}

static struct platform_driver twl4030_pwrbutton_driver = {
    .remove     = __exit_p(twl4030_pwrbutton_remove),
    .driver     = {
        .name   = "twl4030_pwrbutton",
        .owner  = THIS_MODULE,
    },
};

static int __init twl4030_pwrbutton_init(void)
{
    return platform_driver_probe(&twl4030_pwrbutton_driver,
            twl4030_pwrbutton_probe);
}
module_init(twl4030_pwrbutton_init);

static void __exit twl4030_pwrbutton_exit(void)
{
    platform_driver_unregister(&twl4030_pwrbutton_driver);
}
module_exit(twl4030_pwrbutton_exit);

MODULE_ALIAS("platform:twl4030_pwrbutton");
MODULE_DESCRIPTION("Triton2 Power Button");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Peter De Schrijver <[email protected]>");
MODULE_AUTHOR("Felipe Balbi <[email protected]>");