drivers/iio/gyro/st_gyro_buffer.c

   1 /*
   2  * STMicroelectronics gyroscopes 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_gyro.h"
  25
  26 int st_gyro_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_gyro_buffer_preenable(struct iio_dev *indio_dev)
  34 {
  35         return st_sensors_set_enable(indio_dev, true);
  36 }
  37
  38 static int st_gyro_buffer_postenable(struct iio_dev *indio_dev)
  39 {
  40         int err;
  41         struct st_sensor_data *gdata = iio_priv(indio_dev);
  42
  43         gdata->buffer_data = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
  44         if (gdata->buffer_data == NULL) {
  45                 err = -ENOMEM;
  46                 goto allocate_memory_error;
  47         }
  48
  49         err = st_sensors_set_axis_enable(indio_dev,
  50                                         (u8)indio_dev->active_scan_mask[0]);
  51         if (err < 0)
  52                 goto st_gyro_buffer_postenable_error;
  53
  54         err = iio_triggered_buffer_postenable(indio_dev);
  55         if (err < 0)
  56                 goto st_gyro_buffer_postenable_error;
  57
  58         return err;
  59
  60 st_gyro_buffer_postenable_error:
  61         kfree(gdata->buffer_data);
  62 allocate_memory_error:
  63         return err;
  64 }
  65
  66 static int st_gyro_buffer_predisable(struct iio_dev *indio_dev)
  67 {
  68         int err;
  69         struct st_sensor_data *gdata = iio_priv(indio_dev);
  70
  71         err = iio_triggered_buffer_predisable(indio_dev);
  72         if (err < 0)
  73                 goto st_gyro_buffer_predisable_error;
  74
  75         err = st_sensors_set_axis_enable(indio_dev, ST_SENSORS_ENABLE_ALL_AXIS);
  76         if (err < 0)
  77                 goto st_gyro_buffer_predisable_error;
  78
  79         err = st_sensors_set_enable(indio_dev, false);
  80
  81 st_gyro_buffer_predisable_error:
  82         kfree(gdata->buffer_data);
  83         return err;
  84 }
  85
  86 static const struct iio_buffer_setup_ops st_gyro_buffer_setup_ops = {
  87         .preenable = &st_gyro_buffer_preenable,
  88         .postenable = &st_gyro_buffer_postenable,
  89         .predisable = &st_gyro_buffer_predisable,
  90 };
  91
  92 int st_gyro_allocate_ring(struct iio_dev *indio_dev)
  93 {
  94         return iio_triggered_buffer_setup(indio_dev, NULL,
  95                 &st_sensors_trigger_handler, &st_gyro_buffer_setup_ops);
  96 }
  97
  98 void st_gyro_deallocate_ring(struct iio_dev *indio_dev)
  99 {
 100         iio_triggered_buffer_cleanup(indio_dev);
 101 }
 102
 103 MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
 104 MODULE_DESCRIPTION("STMicroelectronics gyroscopes buffer");
 105 MODULE_LICENSE("GPL v2");