// SPDX-License-Identifier: GPL-2.0-only
/*
 * Industrial I/O - generic interrupt based trigger support
 *
 * Copyright (c) 2008-2013 Jonathan Cameron
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/slab.h>

#include <linux/iio/iio.h>
#include <linux/iio/trigger.h>


struct iio_interrupt_trigger_info {
        unsigned int irq;
};

static irqreturn_t iio_interrupt_trigger_poll(int irq, void *private)
{
        iio_trigger_poll(private);
        return IRQ_HANDLED;
}

static int iio_interrupt_trigger_probe(struct platform_device *pdev)
{
        struct iio_interrupt_trigger_info *trig_info;
        struct iio_trigger *trig;
        unsigned long irqflags;
        struct resource *irq_res;
        int irq, ret = 0;

        irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);

        if (irq_res == NULL)
                return -ENODEV;

        irqflags = (irq_res->flags & IRQF_TRIGGER_MASK) | IRQF_SHARED;

        irq = irq_res->start;

        trig = iio_trigger_alloc(NULL, "irqtrig%d", irq);
        if (!trig) {
                ret = -ENOMEM;
                goto error_ret;
        }

        trig_info = kzalloc_obj(*trig_info);
        if (!trig_info) {
                ret = -ENOMEM;
                goto error_free_trigger;
        }
        iio_trigger_set_drvdata(trig, trig_info);
        trig_info->irq = irq;
        ret = request_irq(irq, iio_interrupt_trigger_poll,
                          irqflags, trig->name, trig);
        if (ret) {
                dev_err(&pdev->dev,
                        "request IRQ-%d failed", irq);
                goto error_free_trig_info;
        }

        ret = iio_trigger_register(trig);
        if (ret)
                goto error_release_irq;
        platform_set_drvdata(pdev, trig);

        return 0;

/* First clean up the partly allocated trigger */
error_release_irq:
        free_irq(irq, trig);
error_free_trig_info:
        kfree(trig_info);
error_free_trigger:
        iio_trigger_free(trig);
error_ret:
        return ret;
}

static void iio_interrupt_trigger_remove(struct platform_device *pdev)
{
        struct iio_trigger *trig;
        struct iio_interrupt_trigger_info *trig_info;

        trig = platform_get_drvdata(pdev);
        trig_info = iio_trigger_get_drvdata(trig);
        iio_trigger_unregister(trig);
        free_irq(trig_info->irq, trig);
        kfree(trig_info);
        iio_trigger_free(trig);
}

static struct platform_driver iio_interrupt_trigger_driver = {
        .probe = iio_interrupt_trigger_probe,
        .remove = iio_interrupt_trigger_remove,
        .driver = {
                .name = "iio_interrupt_trigger",
        },
};

module_platform_driver(iio_interrupt_trigger_driver);

MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
MODULE_DESCRIPTION("Interrupt trigger for the iio subsystem");
MODULE_LICENSE("GPL v2");