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