max8925_onkey.c

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#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/i2c.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/mfd/max8925.h>
#include <linux/slab.h>

#define SW_INPUT        (1 << 7)    /* 0/1 -- up/down */
#define HARDRESET_EN        (1 << 7)
#define PWREN_EN        (1 << 7)

struct max8925_onkey_info {
    struct input_dev    *idev;
    struct i2c_client   *i2c;
    struct device       *dev;
    unsigned int        irq[2];
};

/*
 * MAX8925 gives us an interrupt when ONKEY is pressed or released.
 * max8925_set_bits() operates I2C bus and may sleep. So implement
 * it in thread IRQ handler.
 */
static irqreturn_t max8925_onkey_handler(int irq, void *data)
{
    struct max8925_onkey_info *info = data;
    int state;

    state = max8925_reg_read(info->i2c, MAX8925_ON_OFF_STATUS);

    input_report_key(info->idev, KEY_POWER, state & SW_INPUT);
    input_sync(info->idev);

    dev_dbg(info->dev, "onkey state:%d\n", state);

    /* Enable hardreset to halt if system isn't shutdown on time */
    max8925_set_bits(info->i2c, MAX8925_SYSENSEL,
             HARDRESET_EN, HARDRESET_EN);

    return IRQ_HANDLED;
}

static int __devinit max8925_onkey_probe(struct platform_device *pdev)
{
    struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
    struct max8925_onkey_info *info;
    struct input_dev *input;
    int irq[2], error;

    irq[0] = platform_get_irq(pdev, 0);
    if (irq[0] < 0) {
        dev_err(&pdev->dev, "No IRQ resource!\n");
        return -EINVAL;
    }

    irq[1] = platform_get_irq(pdev, 1);
    if (irq[1] < 0) {
        dev_err(&pdev->dev, "No IRQ resource!\n");
        return -EINVAL;
    }

    info = kzalloc(sizeof(struct max8925_onkey_info), GFP_KERNEL);
    input = input_allocate_device();
    if (!info || !input) {
        error = -ENOMEM;
        goto err_free_mem;
    }

    info->idev = input;
    info->i2c = chip->i2c;
    info->dev = &pdev->dev;
    info->irq[0] = irq[0];
    info->irq[1] = irq[1];

    input->name = "max8925_on";
    input->phys = "max8925_on/input0";
    input->id.bustype = BUS_I2C;
    input->dev.parent = &pdev->dev;
    input_set_capability(input, EV_KEY, KEY_POWER);

    irq[0] += chip->irq_base;
    irq[1] += chip->irq_base;

    error = request_threaded_irq(irq[0], NULL, max8925_onkey_handler,
                     IRQF_ONESHOT, "onkey-down", info);
    if (error < 0) {
        dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
            irq[0], error);
        goto err_free_mem;
    }

    error = request_threaded_irq(irq[1], NULL, max8925_onkey_handler,
                     IRQF_ONESHOT, "onkey-up", info);
    if (error < 0) {
        dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
            irq[1], error);
        goto err_free_irq0;
    }

    error = input_register_device(info->idev);
    if (error) {
        dev_err(chip->dev, "Can't register input device: %d\n", error);
        goto err_free_irq1;
    }

    platform_set_drvdata(pdev, info);
    device_init_wakeup(&pdev->dev, 1);

    return 0;

err_free_irq1:
    free_irq(irq[1], info);
err_free_irq0:
    free_irq(irq[0], info);
err_free_mem:
    input_free_device(input);
    kfree(info);

    return error;
}

static int __devexit max8925_onkey_remove(struct platform_device *pdev)
{
    struct max8925_onkey_info *info = platform_get_drvdata(pdev);
    struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);

    free_irq(info->irq[0] + chip->irq_base, info);
    free_irq(info->irq[1] + chip->irq_base, info);
    input_unregister_device(info->idev);
    kfree(info);

    platform_set_drvdata(pdev, NULL);

    return 0;
}

#ifdef CONFIG_PM_SLEEP
static int max8925_onkey_suspend(struct device *dev)
{
    struct platform_device *pdev = to_platform_device(dev);
    struct max8925_onkey_info *info = platform_get_drvdata(pdev);
    struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);

    if (device_may_wakeup(dev)) {
        chip->wakeup_flag |= 1 << info->irq[0];
        chip->wakeup_flag |= 1 << info->irq[1];
    }

    return 0;
}

static int max8925_onkey_resume(struct device *dev)
{
    struct platform_device *pdev = to_platform_device(dev);
    struct max8925_onkey_info *info = platform_get_drvdata(pdev);
    struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);

    if (device_may_wakeup(dev)) {
        chip->wakeup_flag &= ~(1 << info->irq[0]);
        chip->wakeup_flag &= ~(1 << info->irq[1]);
    }

    return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(max8925_onkey_pm_ops, max8925_onkey_suspend, max8925_onkey_resume);

static struct platform_driver max8925_onkey_driver = {
    .driver     = {
        .name   = "max8925-onkey",
        .owner  = THIS_MODULE,
        .pm = &max8925_onkey_pm_ops,
    },
    .probe      = max8925_onkey_probe,
    .remove     = __devexit_p(max8925_onkey_remove),
};
module_platform_driver(max8925_onkey_driver);

MODULE_DESCRIPTION("Maxim MAX8925 ONKEY driver");
MODULE_AUTHOR("Haojian Zhuang <[email protected]>");
MODULE_LICENSE("GPL");