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 	.owner = THIS_MODULE,
33 };
34 
35 static 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_free_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 */
82 error_release_irq:
83 	free_irq(irq, trig);
84 error_free_trig_info:
85 	kfree(trig_info);
86 error_free_trigger:
87 	iio_trigger_free(trig);
88 error_ret:
89 	return ret;
90 }
91 
92 static 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_free(trig);
103 
104 	return 0;
105 }
106 
107 static 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 
115 module_platform_driver(iio_interrupt_trigger_driver);
116 
117 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
118 MODULE_DESCRIPTION("Interrupt trigger for the iio subsystem");
119 MODULE_LICENSE("GPL v2");
120