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 
21 struct iio_interrupt_trigger_info {
22 	unsigned int irq;
23 };
24 
25 static irqreturn_t iio_interrupt_trigger_poll(int irq, void *private)
26 {
27 	/* Timestamp not currently provided */
28 	iio_trigger_poll(private, 0);
29 	return IRQ_HANDLED;
30 }
31 
32 static const struct iio_trigger_ops iio_interrupt_trigger_ops = {
33 	.owner = THIS_MODULE,
34 };
35 
36 static int iio_interrupt_trigger_probe(struct platform_device *pdev)
37 {
38 	struct iio_interrupt_trigger_info *trig_info;
39 	struct iio_trigger *trig;
40 	unsigned long irqflags;
41 	struct resource *irq_res;
42 	int irq, ret = 0;
43 
44 	irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
45 
46 	if (irq_res == NULL)
47 		return -ENODEV;
48 
49 	irqflags = (irq_res->flags & IRQF_TRIGGER_MASK) | IRQF_SHARED;
50 
51 	irq = irq_res->start;
52 
53 	trig = iio_trigger_alloc("irqtrig%d", irq_res->start);
54 	if (!trig) {
55 		ret = -ENOMEM;
56 		goto error_ret;
57 	}
58 
59 	trig_info = kzalloc(sizeof(*trig_info), GFP_KERNEL);
60 	if (!trig_info) {
61 		ret = -ENOMEM;
62 		goto error_put_trigger;
63 	}
64 	iio_trigger_set_drvdata(trig, trig_info);
65 	trig_info->irq = irq;
66 	trig->ops = &iio_interrupt_trigger_ops;
67 	ret = request_irq(irq, iio_interrupt_trigger_poll,
68 			  irqflags, trig->name, trig);
69 	if (ret) {
70 		dev_err(&pdev->dev,
71 			"request IRQ-%d failed", irq);
72 		goto error_free_trig_info;
73 	}
74 
75 	ret = iio_trigger_register(trig);
76 	if (ret)
77 		goto error_release_irq;
78 	platform_set_drvdata(pdev, trig);
79 
80 	return 0;
81 
82 /* First clean up the partly allocated trigger */
83 error_release_irq:
84 	free_irq(irq, trig);
85 error_free_trig_info:
86 	kfree(trig_info);
87 error_put_trigger:
88 	iio_trigger_put(trig);
89 error_ret:
90 	return ret;
91 }
92 
93 static int iio_interrupt_trigger_remove(struct platform_device *pdev)
94 {
95 	struct iio_trigger *trig;
96 	struct iio_interrupt_trigger_info *trig_info;
97 
98 	trig = platform_get_drvdata(pdev);
99 	trig_info = iio_trigger_get_drvdata(trig);
100 	iio_trigger_unregister(trig);
101 	free_irq(trig_info->irq, trig);
102 	kfree(trig_info);
103 	iio_trigger_put(trig);
104 
105 	return 0;
106 }
107 
108 static struct platform_driver iio_interrupt_trigger_driver = {
109 	.probe = iio_interrupt_trigger_probe,
110 	.remove = iio_interrupt_trigger_remove,
111 	.driver = {
112 		.name = "iio_interrupt_trigger",
113 		.owner = THIS_MODULE,
114 	},
115 };
116 
117 module_platform_driver(iio_interrupt_trigger_driver);
118 
119 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
120 MODULE_DESCRIPTION("Interrupt trigger for the iio subsystem");
121 MODULE_LICENSE("GPL v2");
122