1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
|
/*
* Industrial I/O in kernel consumer interface
*
* Copyright (c) 2011 Jonathan Cameron
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*/
#ifndef _IIO_INKERN_CONSUMER_H_
#define _IIO_INKERN_CONSUMER_H_
#include <linux/types.h>
#include <linux/iio/types.h>
struct iio_dev;
struct iio_chan_spec;
struct device;
/**
* struct iio_channel - everything needed for a consumer to use a channel
* @indio_dev: Device on which the channel exists.
* @channel: Full description of the channel.
* @data: Data about the channel used by consumer.
*/
struct iio_channel {
struct iio_dev *indio_dev;
const struct iio_chan_spec *channel;
void *data;
};
/**
* iio_channel_get() - get description of all that is needed to access channel.
* @dev: Pointer to consumer device. Device name must match
* the name of the device as provided in the iio_map
* with which the desired provider to consumer mapping
* was registered.
* @consumer_channel: Unique name to identify the channel on the consumer
* side. This typically describes the channels use within
* the consumer. E.g. 'battery_voltage'
*/
struct iio_channel *iio_channel_get(struct device *dev,
const char *consumer_channel);
/**
* iio_channel_release() - release channels obtained via iio_channel_get
* @chan: The channel to be released.
*/
void iio_channel_release(struct iio_channel *chan);
/**
* iio_channel_get_all() - get all channels associated with a client
* @dev: Pointer to consumer device.
*
* Returns an array of iio_channel structures terminated with one with
* null iio_dev pointer.
* This function is used by fairly generic consumers to get all the
* channels registered as having this consumer.
*/
struct iio_channel *iio_channel_get_all(struct device *dev);
/**
* iio_channel_release_all() - reverse iio_channel_get_all
* @chan: Array of channels to be released.
*/
void iio_channel_release_all(struct iio_channel *chan);
struct iio_cb_buffer;
/**
* iio_channel_get_all_cb() - register callback for triggered capture
* @dev: Pointer to client device.
* @cb: Callback function.
* @private: Private data passed to callback.
*
* NB right now we have no ability to mux data from multiple devices.
* So if the channels requested come from different devices this will
* fail.
*/
struct iio_cb_buffer *iio_channel_get_all_cb(struct device *dev,
int (*cb)(const void *data,
void *private),
void *private);
/**
* iio_channel_release_all_cb() - release and unregister the callback.
* @cb_buffer: The callback buffer that was allocated.
*/
void iio_channel_release_all_cb(struct iio_cb_buffer *cb_buffer);
/**
* iio_channel_start_all_cb() - start the flow of data through callback.
* @cb_buff: The callback buffer we are starting.
*/
int iio_channel_start_all_cb(struct iio_cb_buffer *cb_buff);
/**
* iio_channel_stop_all_cb() - stop the flow of data through the callback.
* @cb_buff: The callback buffer we are stopping.
*/
void iio_channel_stop_all_cb(struct iio_cb_buffer *cb_buff);
/**
* iio_channel_cb_get_channels() - get access to the underlying channels.
* @cb_buff: The callback buffer from whom we want the channel
* information.
*
* This function allows one to obtain information about the channels.
* Whilst this may allow direct reading if all buffers are disabled, the
* primary aim is to allow drivers that are consuming a channel to query
* things like scaling of the channel.
*/
struct iio_channel
*iio_channel_cb_get_channels(const struct iio_cb_buffer *cb_buffer);
/**
* iio_read_channel_raw() - read from a given channel
* @chan: The channel being queried.
* @val: Value read back.
*
* Note raw reads from iio channels are in adc counts and hence
* scale will need to be applied if standard units required.
*/
int iio_read_channel_raw(struct iio_channel *chan,
int *val);
/**
* iio_read_channel_average_raw() - read from a given channel
* @chan: The channel being queried.
* @val: Value read back.
*
* Note raw reads from iio channels are in adc counts and hence
* scale will need to be applied if standard units required.
*
* In opposit to the normal iio_read_channel_raw this function
* returns the average of multiple reads.
*/
int iio_read_channel_average_raw(struct iio_channel *chan, int *val);
/**
* iio_read_channel_processed() - read processed value from a given channel
* @chan: The channel being queried.
* @val: Value read back.
*
* Returns an error code or 0.
*
* This function will read a processed value from a channel. A processed value
* means that this value will have the correct unit and not some device internal
* representation. If the device does not support reporting a processed value
* the function will query the raw value and the channels scale and offset and
* do the appropriate transformation.
*/
int iio_read_channel_processed(struct iio_channel *chan, int *val);
/**
* iio_write_channel_raw() - write to a given channel
* @chan: The channel being queried.
* @val: Value being written.
*
* Note raw writes to iio channels are in dac counts and hence
* scale will need to be applied if standard units required.
*/
int iio_write_channel_raw(struct iio_channel *chan, int val);
/**
* iio_get_channel_type() - get the type of a channel
* @channel: The channel being queried.
* @type: The type of the channel.
*
* returns the enum iio_chan_type of the channel
*/
int iio_get_channel_type(struct iio_channel *channel,
enum iio_chan_type *type);
/**
* iio_read_channel_scale() - read the scale value for a channel
* @chan: The channel being queried.
* @val: First part of value read back.
* @val2: Second part of value read back.
*
* Note returns a description of what is in val and val2, such
* as IIO_VAL_INT_PLUS_MICRO telling us we have a value of val
* + val2/1e6
*/
int iio_read_channel_scale(struct iio_channel *chan, int *val,
int *val2);
/**
* iio_convert_raw_to_processed() - Converts a raw value to a processed value
* @chan: The channel being queried
* @raw: The raw IIO to convert
* @processed: The result of the conversion
* @scale: Scale factor to apply during the conversion
*
* Returns an error code or 0.
*
* This function converts a raw value to processed value for a specific channel.
* A raw value is the device internal representation of a sample and the value
* returned by iio_read_channel_raw, so the unit of that value is device
* depended. A processed value on the other hand is value has a normed unit
* according with the IIO specification.
*
* The scale factor allows to increase the precession of the returned value. For
* a scale factor of 1 the function will return the result in the normal IIO
* unit for the channel type. E.g. millivolt for voltage channels, if you want
* nanovolts instead pass 1000 as the scale factor.
*/
int iio_convert_raw_to_processed(struct iio_channel *chan, int raw,
int *processed, unsigned int scale);
#endif
|
