drivers/iio/trigger/iio-trig-interrupt.c

   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("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");