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