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 static int st_magn_buffer_preenable(struct iio_dev *indio_dev)
  27 {
  28         int err;
  29
  30         err = st_sensors_set_enable(indio_dev, true);
  31         if (err < 0)
  32                 goto st_magn_set_enable_error;
  33
  34         err = iio_sw_buffer_preenable(indio_dev);
  35
  36 st_magn_set_enable_error:
  37         return err;
  38 }
  39
  40 static int st_magn_buffer_postenable(struct iio_dev *indio_dev)
  41 {
  42         int err;
  43         struct st_sensor_data *mdata = iio_priv(indio_dev);
  44
  45         mdata->buffer_data = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
  46         if (mdata->buffer_data == NULL) {
  47                 err = -ENOMEM;
  48                 goto allocate_memory_error;
  49         }
  50
  51         err = iio_triggered_buffer_postenable(indio_dev);
  52         if (err < 0)
  53                 goto st_magn_buffer_postenable_error;
  54
  55         return err;
  56
  57 st_magn_buffer_postenable_error:
  58         kfree(mdata->buffer_data);
  59 allocate_memory_error:
  60         return err;
  61 }
  62
  63 static int st_magn_buffer_predisable(struct iio_dev *indio_dev)
  64 {
  65         int err;
  66         struct st_sensor_data *mdata = iio_priv(indio_dev);
  67
  68         err = iio_triggered_buffer_predisable(indio_dev);
  69         if (err < 0)
  70                 goto st_magn_buffer_predisable_error;
  71
  72         err = st_sensors_set_enable(indio_dev, false);
  73
  74 st_magn_buffer_predisable_error:
  75         kfree(mdata->buffer_data);
  76         return err;
  77 }
  78
  79 static const struct iio_buffer_setup_ops st_magn_buffer_setup_ops = {
  80         .preenable = &st_magn_buffer_preenable,
  81         .postenable = &st_magn_buffer_postenable,
  82         .predisable = &st_magn_buffer_predisable,
  83 };
  84
  85 int st_magn_allocate_ring(struct iio_dev *indio_dev)
  86 {
  87         return iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
  88                 &st_sensors_trigger_handler, &st_magn_buffer_setup_ops);
  89 }
  90
  91 void st_magn_deallocate_ring(struct iio_dev *indio_dev)
  92 {
  93         iio_triggered_buffer_cleanup(indio_dev);
  94 }
  95
  96 MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
  97 MODULE_DESCRIPTION("STMicroelectronics magnetometers buffer");
  98 MODULE_LICENSE("GPL v2");