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
iio_interrupt_trigger_poll(int irq,void * private)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
iio_interrupt_trigger_probe(struct platform_device * pdev)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
iio_interrupt_trigger_remove(struct platform_device * pdev)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