kernel/drivers/staging/iio/meter/ade7758_trigger.c

   1 /*
   2  * ADE7758 Poly Phase Multifunction Energy Metering IC driver
   3  *
   4  * Copyright 2010-2011 Analog Devices Inc.
   5  *
   6  * Licensed under the GPL-2.
   7  */
   8
   9 #include <linux/interrupt.h>
  10 #include <linux/kernel.h>
  11 #include <linux/spi/spi.h>
  12 #include <linux/export.h>
  13
  14 #include <linux/iio/iio.h>
  15 #include <linux/iio/trigger.h>
  16 #include "ade7758.h"
  17
  18 /**
  19  * ade7758_data_rdy_trig_poll() the event handler for the data rdy trig
  20  **/
  21 static irqreturn_t ade7758_data_rdy_trig_poll(int irq, void *private)
  22 {
  23         disable_irq_nosync(irq);
  24         iio_trigger_poll(private);
  25
  26         return IRQ_HANDLED;
  27 }
  28
  29 /**
  30  * ade7758_data_rdy_trigger_set_state() set datardy interrupt state
  31  **/
  32 static int ade7758_data_rdy_trigger_set_state(struct iio_trigger *trig,
  33                                                 bool state)
  34 {
  35         struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
  36
  37         dev_dbg(&indio_dev->dev, "%s (%d)\n", __func__, state);
  38         return ade7758_set_irq(&indio_dev->dev, state);
  39 }
  40
  41 /**
  42  * ade7758_trig_try_reen() try renabling irq for data rdy trigger
  43  * @trig:       the datardy trigger
  44  **/
  45 static int ade7758_trig_try_reen(struct iio_trigger *trig)
  46 {
  47         struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
  48         struct ade7758_state *st = iio_priv(indio_dev);
  49
  50         enable_irq(st->us->irq);
  51         /* irq reenabled so success! */
  52         return 0;
  53 }
  54
  55 static const struct iio_trigger_ops ade7758_trigger_ops = {
  56         .owner = THIS_MODULE,
  57         .set_trigger_state = &ade7758_data_rdy_trigger_set_state,
  58         .try_reenable = &ade7758_trig_try_reen,
  59 };
  60
  61 int ade7758_probe_trigger(struct iio_dev *indio_dev)
  62 {
  63         struct ade7758_state *st = iio_priv(indio_dev);
  64         int ret;
  65
  66         st->trig = iio_trigger_alloc("%s-dev%d",
  67                                         spi_get_device_id(st->us)->name,
  68                                         indio_dev->id);
  69         if (!st->trig) {
  70                 ret = -ENOMEM;
  71                 goto error_ret;
  72         }
  73
  74         ret = request_irq(st->us->irq,
  75                           ade7758_data_rdy_trig_poll,
  76                           IRQF_TRIGGER_LOW,
  77                           spi_get_device_id(st->us)->name,
  78                           st->trig);
  79         if (ret)
  80                 goto error_free_trig;
  81
  82         st->trig->dev.parent = &st->us->dev;
  83         st->trig->ops = &ade7758_trigger_ops;
  84         iio_trigger_set_drvdata(st->trig, indio_dev);
  85         ret = iio_trigger_register(st->trig);
  86
  87         /* select default trigger */
  88         indio_dev->trig = iio_trigger_get(st->trig);
  89         if (ret)
  90                 goto error_free_irq;
  91
  92         return 0;
  93
  94 error_free_irq:
  95         free_irq(st->us->irq, st->trig);
  96 error_free_trig:
  97         iio_trigger_free(st->trig);
  98 error_ret:
  99         return ret;
 100 }
 101
 102 void ade7758_remove_trigger(struct iio_dev *indio_dev)
 103 {
 104         struct ade7758_state *st = iio_priv(indio_dev);
 105
 106         iio_trigger_unregister(st->trig);
 107         free_irq(st->us->irq, st->trig);
 108         iio_trigger_free(st->trig);
 109 }