GNU Linux-libre 4.9.282-gnu1
[releases.git] / drivers / iio / trigger / iio-trig-interrupt.c
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");