drivers/iio/magnetometer/st_magn_buffer.c

   1 /*
   2  * STMicroelectronics magnetometers driver
   3  *
   4  * Copyright 2012-2013 STMicroelectronics Inc.
   5  *
   6  * Denis Ciocca <denis.ciocca@st.com>
   7  *
   8  * Licensed under the GPL-2.
   9  */
  10
  11 #include <linux/module.h>
  12 #include <linux/kernel.h>
  13 #include <linux/slab.h>
  14 #include <linux/stat.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/i2c.h>
  17 #include <linux/delay.h>
  18 #include <linux/iio/iio.h>
  19 #include <linux/iio/buffer.h>
  20 #include <linux/iio/trigger_consumer.h>
  21 #include <linux/iio/triggered_buffer.h>
  22
  23 #include <linux/iio/common/st_sensors.h>
  24 #include "st_magn.h"
  25
  26 int st_magn_trig_set_state(struct iio_trigger *trig, bool state)
  27 {
  28         struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
  29
  30         return st_sensors_set_dataready_irq(indio_dev, state);
  31 }
  32
  33 static int st_magn_buffer_postenable(struct iio_dev *indio_dev)
  34 {
  35         int err;
  36         struct st_sensor_data *mdata = iio_priv(indio_dev);
  37
  38         mdata->buffer_data = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
  39         if (mdata->buffer_data == NULL) {
  40                 err = -ENOMEM;
  41                 goto allocate_memory_error;
  42         }
  43
  44         err = iio_triggered_buffer_postenable(indio_dev);
  45         if (err < 0)
  46                 goto st_magn_buffer_postenable_error;
  47
  48         return st_sensors_set_enable(indio_dev, true);
  49
  50 st_magn_buffer_postenable_error:
  51         kfree(mdata->buffer_data);
  52 allocate_memory_error:
  53         return err;
  54 }
  55
  56 static int st_magn_buffer_predisable(struct iio_dev *indio_dev)
  57 {
  58         int err;
  59         struct st_sensor_data *mdata = iio_priv(indio_dev);
  60
  61         err = st_sensors_set_enable(indio_dev, false);
  62         if (err < 0)
  63                 goto st_magn_buffer_predisable_error;
  64
  65         err = iio_triggered_buffer_predisable(indio_dev);
  66
  67 st_magn_buffer_predisable_error:
  68         kfree(mdata->buffer_data);
  69         return err;
  70 }
  71
  72 static const struct iio_buffer_setup_ops st_magn_buffer_setup_ops = {
  73         .postenable = &st_magn_buffer_postenable,
  74         .predisable = &st_magn_buffer_predisable,
  75 };
  76
  77 int st_magn_allocate_ring(struct iio_dev *indio_dev)
  78 {
  79         return iio_triggered_buffer_setup(indio_dev, NULL,
  80                 &st_sensors_trigger_handler, &st_magn_buffer_setup_ops);
  81 }
  82
  83 void st_magn_deallocate_ring(struct iio_dev *indio_dev)
  84 {
  85         iio_triggered_buffer_cleanup(indio_dev);
  86 }
  87
  88 MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
  89 MODULE_DESCRIPTION("STMicroelectronics magnetometers buffer");
  90 MODULE_LICENSE("GPL v2");