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");