iio-trig-interrupt.c
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/*
* Industrial I/O - generic interrupt based trigger support
*
* Copyright (c) 2008-2013 Jonathan Cameron
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*/
#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)
{
/* Timestamp not currently provided */
iio_trigger_poll(private, 0);
return IRQ_HANDLED;
}
static const struct iio_trigger_ops iio_interrupt_trigger_ops = {
.owner = THIS_MODULE,
};
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("irqtrig%d", irq);
if (!trig) {
ret = -ENOMEM;
goto error_ret;
}
trig_info = kzalloc(sizeof(*trig_info), GFP_KERNEL);
if (!trig_info) {
ret = -ENOMEM;
goto error_put_trigger;
}
iio_trigger_set_drvdata(trig, trig_info);
trig_info->irq = irq;
trig->ops = &iio_interrupt_trigger_ops;
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_put_trigger:
iio_trigger_put(trig);
error_ret:
return ret;
}
static int 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_put(trig);
return 0;
}
static struct platform_driver iio_interrupt_trigger_driver = {
.probe = iio_interrupt_trigger_probe,
.remove = iio_interrupt_trigger_remove,
.driver = {
.name = "iio_interrupt_trigger",
.owner = THIS_MODULE,
},
};
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");