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 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 void 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
  97 static struct platform_driver iio_interrupt_trigger_driver = {
  98         .probe = iio_interrupt_trigger_probe,
  99         .remove_new = iio_interrupt_trigger_remove,
 100         .driver = {
 101                 .name = "iio_interrupt_trigger",
 102         },
 103 };
 104
 105 module_platform_driver(iio_interrupt_trigger_driver);
 106
 107 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
 108 MODULE_DESCRIPTION("Interrupt trigger for the iio subsystem");
 109 MODULE_LICENSE("GPL v2");