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 	iio_trigger_poll(private);
28 	return IRQ_HANDLED;
29 }
30 
31 static const struct iio_trigger_ops iio_interrupt_trigger_ops = {
32 };
33 
34 static int iio_interrupt_trigger_probe(struct platform_device *pdev)
35 {
36 	struct iio_interrupt_trigger_info *trig_info;
37 	struct iio_trigger *trig;
38 	unsigned long irqflags;
39 	struct resource *irq_res;
40 	int irq, ret = 0;
41 
42 	irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
43 
44 	if (irq_res == NULL)
45 		return -ENODEV;
46 
47 	irqflags = (irq_res->flags & IRQF_TRIGGER_MASK) | IRQF_SHARED;
48 
49 	irq = irq_res->start;
50 
51 	trig = iio_trigger_alloc("irqtrig%d", irq);
52 	if (!trig) {
53 		ret = -ENOMEM;
54 		goto error_ret;
55 	}
56 
57 	trig_info = kzalloc(sizeof(*trig_info), GFP_KERNEL);
58 	if (!trig_info) {
59 		ret = -ENOMEM;
60 		goto error_free_trigger;
61 	}
62 	iio_trigger_set_drvdata(trig, trig_info);
63 	trig_info->irq = irq;
64 	trig->ops = &iio_interrupt_trigger_ops;
65 	ret = request_irq(irq, iio_interrupt_trigger_poll,
66 			  irqflags, trig->name, trig);
67 	if (ret) {
68 		dev_err(&pdev->dev,
69 			"request IRQ-%d failed", irq);
70 		goto error_free_trig_info;
71 	}
72 
73 	ret = iio_trigger_register(trig);
74 	if (ret)
75 		goto error_release_irq;
76 	platform_set_drvdata(pdev, trig);
77 
78 	return 0;
79 
80 /* First clean up the partly allocated trigger */
81 error_release_irq:
82 	free_irq(irq, trig);
83 error_free_trig_info:
84 	kfree(trig_info);
85 error_free_trigger:
86 	iio_trigger_free(trig);
87 error_ret:
88 	return ret;
89 }
90 
91 static int iio_interrupt_trigger_remove(struct platform_device *pdev)
92 {
93 	struct iio_trigger *trig;
94 	struct iio_interrupt_trigger_info *trig_info;
95 
96 	trig = platform_get_drvdata(pdev);
97 	trig_info = iio_trigger_get_drvdata(trig);
98 	iio_trigger_unregister(trig);
99 	free_irq(trig_info->irq, trig);
100 	kfree(trig_info);
101 	iio_trigger_free(trig);
102 
103 	return 0;
104 }
105 
106 static struct platform_driver iio_interrupt_trigger_driver = {
107 	.probe = iio_interrupt_trigger_probe,
108 	.remove = iio_interrupt_trigger_remove,
109 	.driver = {
110 		.name = "iio_interrupt_trigger",
111 	},
112 };
113 
114 module_platform_driver(iio_interrupt_trigger_driver);
115 
116 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
117 MODULE_DESCRIPTION("Interrupt trigger for the iio subsystem");
118 MODULE_LICENSE("GPL v2");
119