// SPDX-License-Identifier: GPL-2.0-only
/*
 *  Input driver for PCAP events:
 *   * Power key
 *   * Headphone button
 *
 *  Copyright (c) 2008,2009 Ilya Petrov <ilya.muromec@gmail.com>
 */

#include <linux/module.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 pcap_keys_probe(struct platform_device *pdev)
{
        int err = -ENOMEM;
        struct pcap_keys *pcap_keys;
        struct input_dev *input_dev;

        pcap_keys = kmalloc_obj(*pcap_keys);
        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 void 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);
}

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

MODULE_DESCRIPTION("Motorola PCAP2 input events driver");
MODULE_AUTHOR("Ilya Petrov <ilya.muromec@gmail.com>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:pcap_keys");