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 };
  33
  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
  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");