1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Industrial I/O - generic interrupt based trigger support
4  *
5  * Copyright (c) 2008-2013 Jonathan Cameron
6  */
7 
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/platform_device.h>
11 #include <linux/interrupt.h>
12 #include <linux/slab.h>
13 
14 #include <linux/iio/iio.h>
15 #include <linux/iio/trigger.h>
16 
17 
18 struct iio_interrupt_trigger_info {
19 	unsigned int irq;
20 };
21 
22 static irqreturn_t iio_interrupt_trigger_poll(int irq, void *private)
23 {
24 	iio_trigger_poll(private);
25 	return IRQ_HANDLED;
26 }
27 
28 static const struct iio_trigger_ops iio_interrupt_trigger_ops = {
29 };
30 
31 static int iio_interrupt_trigger_probe(struct platform_device *pdev)
32 {
33 	struct iio_interrupt_trigger_info *trig_info;
34 	struct iio_trigger *trig;
35 	unsigned long irqflags;
36 	struct resource *irq_res;
37 	int irq, ret = 0;
38 
39 	irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
40 
41 	if (irq_res == NULL)
42 		return -ENODEV;
43 
44 	irqflags = (irq_res->flags & IRQF_TRIGGER_MASK) | IRQF_SHARED;
45 
46 	irq = irq_res->start;
47 
48 	trig = iio_trigger_alloc(NULL, "irqtrig%d", irq);
49 	if (!trig) {
50 		ret = -ENOMEM;
51 		goto error_ret;
52 	}
53 
54 	trig_info = kzalloc(sizeof(*trig_info), GFP_KERNEL);
55 	if (!trig_info) {
56 		ret = -ENOMEM;
57 		goto error_free_trigger;
58 	}
59 	iio_trigger_set_drvdata(trig, trig_info);
60 	trig_info->irq = irq;
61 	trig->ops = &iio_interrupt_trigger_ops;
62 	ret = request_irq(irq, iio_interrupt_trigger_poll,
63 			  irqflags, trig->name, trig);
64 	if (ret) {
65 		dev_err(&pdev->dev,
66 			"request IRQ-%d failed", irq);
67 		goto error_free_trig_info;
68 	}
69 
70 	ret = iio_trigger_register(trig);
71 	if (ret)
72 		goto error_release_irq;
73 	platform_set_drvdata(pdev, trig);
74 
75 	return 0;
76 
77 /* First clean up the partly allocated trigger */
78 error_release_irq:
79 	free_irq(irq, trig);
80 error_free_trig_info:
81 	kfree(trig_info);
82 error_free_trigger:
83 	iio_trigger_free(trig);
84 error_ret:
85 	return ret;
86 }
87 
88 static int iio_interrupt_trigger_remove(struct platform_device *pdev)
89 {
90 	struct iio_trigger *trig;
91 	struct iio_interrupt_trigger_info *trig_info;
92 
93 	trig = platform_get_drvdata(pdev);
94 	trig_info = iio_trigger_get_drvdata(trig);
95 	iio_trigger_unregister(trig);
96 	free_irq(trig_info->irq, trig);
97 	kfree(trig_info);
98 	iio_trigger_free(trig);
99 
100 	return 0;
101 }
102 
103 static struct platform_driver iio_interrupt_trigger_driver = {
104 	.probe = iio_interrupt_trigger_probe,
105 	.remove = iio_interrupt_trigger_remove,
106 	.driver = {
107 		.name = "iio_interrupt_trigger",
108 	},
109 };
110 
111 module_platform_driver(iio_interrupt_trigger_driver);
112 
113 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
114 MODULE_DESCRIPTION("Interrupt trigger for the iio subsystem");
115 MODULE_LICENSE("GPL v2");
116