1/*
2 * Industrial I/O - generic interrupt based trigger support
3 *
4 * Copyright (c) 2008-2013 Jonathan Cameron
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 as published by
8 * the Free Software Foundation.
9 */
10
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/platform_device.h>
14#include <linux/interrupt.h>
15#include <linux/slab.h>
16
17#include <linux/iio/iio.h>
18#include <linux/iio/trigger.h>
19
20
21struct iio_interrupt_trigger_info {
22	unsigned int irq;
23};
24
25static irqreturn_t iio_interrupt_trigger_poll(int irq, void *private)
26{
27	iio_trigger_poll(private);
28	return IRQ_HANDLED;
29}
30
31static const struct iio_trigger_ops iio_interrupt_trigger_ops = {
32	.owner = THIS_MODULE,
33};
34
35static int iio_interrupt_trigger_probe(struct platform_device *pdev)
36{
37	struct iio_interrupt_trigger_info *trig_info;
38	struct iio_trigger *trig;
39	unsigned long irqflags;
40	struct resource *irq_res;
41	int irq, ret = 0;
42
43	irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
44
45	if (irq_res == NULL)
46		return -ENODEV;
47
48	irqflags = (irq_res->flags & IRQF_TRIGGER_MASK) | IRQF_SHARED;
49
50	irq = irq_res->start;
51
52	trig = iio_trigger_alloc("irqtrig%d", irq);
53	if (!trig) {
54		ret = -ENOMEM;
55		goto error_ret;
56	}
57
58	trig_info = kzalloc(sizeof(*trig_info), GFP_KERNEL);
59	if (!trig_info) {
60		ret = -ENOMEM;
61		goto error_put_trigger;
62	}
63	iio_trigger_set_drvdata(trig, trig_info);
64	trig_info->irq = irq;
65	trig->ops = &iio_interrupt_trigger_ops;
66	ret = request_irq(irq, iio_interrupt_trigger_poll,
67			  irqflags, trig->name, trig);
68	if (ret) {
69		dev_err(&pdev->dev,
70			"request IRQ-%d failed", irq);
71		goto error_free_trig_info;
72	}
73
74	ret = iio_trigger_register(trig);
75	if (ret)
76		goto error_release_irq;
77	platform_set_drvdata(pdev, trig);
78
79	return 0;
80
81/* First clean up the partly allocated trigger */
82error_release_irq:
83	free_irq(irq, trig);
84error_free_trig_info:
85	kfree(trig_info);
86error_put_trigger:
87	iio_trigger_put(trig);
88error_ret:
89	return ret;
90}
91
92static int iio_interrupt_trigger_remove(struct platform_device *pdev)
93{
94	struct iio_trigger *trig;
95	struct iio_interrupt_trigger_info *trig_info;
96
97	trig = platform_get_drvdata(pdev);
98	trig_info = iio_trigger_get_drvdata(trig);
99	iio_trigger_unregister(trig);
100	free_irq(trig_info->irq, trig);
101	kfree(trig_info);
102	iio_trigger_put(trig);
103
104	return 0;
105}
106
107static struct platform_driver iio_interrupt_trigger_driver = {
108	.probe = iio_interrupt_trigger_probe,
109	.remove = iio_interrupt_trigger_remove,
110	.driver = {
111		.name = "iio_interrupt_trigger",
112	},
113};
114
115module_platform_driver(iio_interrupt_trigger_driver);
116
117MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
118MODULE_DESCRIPTION("Interrupt trigger for the iio subsystem");
119MODULE_LICENSE("GPL v2");
120