drivers/iio/industrialio-triggered-event.c

   1 /*
   2  * Copyright (C) 2015 Cogent Embedded, Inc.
   3  *
   4  * This program is free software; you can redistribute  it and/or modify it
   5  * under  the terms of  the GNU General  Public License as published by the
   6  * Free Software Foundation;  either version 2 of the  License, or (at your
   7  * option) any later version.
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/export.h>
  12 #include <linux/module.h>
  13 #include <linux/iio/iio.h>
  14 #include <linux/iio/triggered_event.h>
  15 #include <linux/iio/trigger_consumer.h>
  16
  17 /**
  18  * iio_triggered_event_setup() - Setup pollfunc_event for triggered event
  19  * @indio_dev:  IIO device structure
  20  * @h:          Function which will be used as pollfunc_event top half
  21  * @thread:     Function which will be used as pollfunc_event bottom half
  22  *
  23  * This function combines some common tasks which will normally be performed
  24  * when setting up a triggered event. It will allocate the pollfunc_event and
  25  * set mode to use it for triggered event.
  26  *
  27  * Before calling this function the indio_dev structure should already be
  28  * completely initialized, but not yet registered. In practice this means that
  29  * this function should be called right before iio_device_register().
  30  *
  31  * To free the resources allocated by this function call
  32  * iio_triggered_event_cleanup().
  33  */
  34 int iio_triggered_event_setup(struct iio_dev *indio_dev,
  35                               irqreturn_t (*h)(int irq, void *p),
  36                               irqreturn_t (*thread)(int irq, void *p))
  37 {
  38         indio_dev->pollfunc_event = iio_alloc_pollfunc(h,
  39                                                        thread,
  40                                                        IRQF_ONESHOT,
  41                                                        indio_dev,
  42                                                        "%s_consumer%d",
  43                                                        indio_dev->name,
  44                                                        indio_dev->id);
  45         if (indio_dev->pollfunc_event == NULL)
  46                 return -ENOMEM;
  47
  48         /* Flag that events polling is possible */
  49         indio_dev->modes |= INDIO_EVENT_TRIGGERED;
  50
  51         return 0;
  52 }
  53 EXPORT_SYMBOL(iio_triggered_event_setup);
  54
  55 /**
  56  * iio_triggered_event_cleanup() - Free resources allocated by iio_triggered_event_setup()
  57  * @indio_dev: IIO device structure
  58  */
  59 void iio_triggered_event_cleanup(struct iio_dev *indio_dev)
  60 {
  61         indio_dev->modes &= ~INDIO_EVENT_TRIGGERED;
  62         iio_dealloc_pollfunc(indio_dev->pollfunc_event);
  63 }
  64 EXPORT_SYMBOL(iio_triggered_event_cleanup);
  65
  66 MODULE_AUTHOR("Vladimir Barinov");
  67 MODULE_DESCRIPTION("IIO helper functions for setting up triggered events");
  68 MODULE_LICENSE("GPL");