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 = trig->private_data;
  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         int err;
  36
  37         err = st_sensors_set_enable(indio_dev, true);
  38         if (err < 0)
  39                 goto st_gyro_set_enable_error;
  40
  41         err = iio_sw_buffer_preenable(indio_dev);
  42
  43 st_gyro_set_enable_error:
  44         return err;
  45 }
  46
  47 static int st_gyro_buffer_postenable(struct iio_dev *indio_dev)
  48 {
  49         int err;
  50         struct st_sensor_data *gdata = iio_priv(indio_dev);
  51
  52         gdata->buffer_data = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
  53         if (gdata->buffer_data == NULL) {
  54                 err = -ENOMEM;
  55                 goto allocate_memory_error;
  56         }
  57
  58         err = st_sensors_set_axis_enable(indio_dev,
  59                                         (u8)indio_dev->active_scan_mask[0]);
  60         if (err < 0)
  61                 goto st_gyro_buffer_postenable_error;
  62
  63         err = iio_triggered_buffer_postenable(indio_dev);
  64         if (err < 0)
  65                 goto st_gyro_buffer_postenable_error;
  66
  67         return err;
  68
  69 st_gyro_buffer_postenable_error:
  70         kfree(gdata->buffer_data);
  71 allocate_memory_error:
  72         return err;
  73 }
  74
  75 static int st_gyro_buffer_predisable(struct iio_dev *indio_dev)
  76 {
  77         int err;
  78         struct st_sensor_data *gdata = iio_priv(indio_dev);
  79
  80         err = iio_triggered_buffer_predisable(indio_dev);
  81         if (err < 0)
  82                 goto st_gyro_buffer_predisable_error;
  83
  84         err = st_sensors_set_axis_enable(indio_dev, ST_SENSORS_ENABLE_ALL_AXIS);
  85         if (err < 0)
  86                 goto st_gyro_buffer_predisable_error;
  87
  88         err = st_sensors_set_enable(indio_dev, false);
  89
  90 st_gyro_buffer_predisable_error:
  91         kfree(gdata->buffer_data);
  92         return err;
  93 }
  94
  95 static const struct iio_buffer_setup_ops st_gyro_buffer_setup_ops = {
  96         .preenable = &st_gyro_buffer_preenable,
  97         .postenable = &st_gyro_buffer_postenable,
  98         .predisable = &st_gyro_buffer_predisable,
  99 };
 100
 101 int st_gyro_allocate_ring(struct iio_dev *indio_dev)
 102 {
 103         return iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
 104                 &st_sensors_trigger_handler, &st_gyro_buffer_setup_ops);
 105 }
 106
 107 void st_gyro_deallocate_ring(struct iio_dev *indio_dev)
 108 {
 109         iio_triggered_buffer_cleanup(indio_dev);
 110 }
 111
 112 MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
 113 MODULE_DESCRIPTION("STMicroelectronics gyroscopes buffer");
 114 MODULE_LICENSE("GPL v2");