aboutsummaryrefslogtreecommitdiff
path: root/drivers/iio/inkern.c
blob: 9a46ca61ef0294fc51f6181a56cb3e165cf11e8e (plain)
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
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
/* The industrial I/O core in kernel channel mapping
 *
 * 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.
 */
#include <linux/err.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/mutex.h>

#include <linux/iio/iio.h>
#include "iio_core.h"
#include <linux/iio/machine.h>
#include <linux/iio/driver.h>
#include <linux/iio/consumer.h>

struct iio_map_internal {
	struct iio_dev *indio_dev;
	struct iio_map *map;
	struct list_head l;
};

static LIST_HEAD(iio_map_list);
static DEFINE_MUTEX(iio_map_list_lock);

int iio_map_array_register(struct iio_dev *indio_dev, struct iio_map *maps)
{
	int i = 0, ret = 0;
	struct iio_map_internal *mapi;

	if (maps == NULL)
		return 0;

	mutex_lock(&iio_map_list_lock);
	while (maps[i].consumer_dev_name != NULL) {
		mapi = kzalloc(sizeof(*mapi), GFP_KERNEL);
		if (mapi == NULL) {
			ret = -ENOMEM;
			goto error_ret;
		}
		mapi->map = &maps[i];
		mapi->indio_dev = indio_dev;
		list_add(&mapi->l, &iio_map_list);
		i++;
	}
error_ret:
	mutex_unlock(&iio_map_list_lock);

	return ret;
}
EXPORT_SYMBOL_GPL(iio_map_array_register);


/* Assumes the exact same array (e.g. memory locations)
 * used at unregistration as used at registration rather than
 * more complex checking of contents.
 */
int iio_map_array_unregister(struct iio_dev *indio_dev,
			     struct iio_map *maps)
{
	int i = 0, ret = 0;
	bool found_it;
	struct iio_map_internal *mapi;

	if (maps == NULL)
		return 0;

	mutex_lock(&iio_map_list_lock);
	while (maps[i].consumer_dev_name != NULL) {
		found_it = false;
		list_for_each_entry(mapi, &iio_map_list, l)
			if (&maps[i] == mapi->map) {
				list_del(&mapi->l);
				kfree(mapi);
				found_it = true;
				break;
			}
		if (found_it == false) {
			ret = -ENODEV;
			goto error_ret;
		}
		i++;
	}
error_ret:
	mutex_unlock(&iio_map_list_lock);

	return ret;
}
EXPORT_SYMBOL_GPL(iio_map_array_unregister);

static const struct iio_chan_spec
*iio_chan_spec_from_name(const struct iio_dev *indio_dev, const char *name)
{
	int i;
	const struct iio_chan_spec *chan = NULL;

	for (i = 0; i < indio_dev->num_channels; i++)
		if (indio_dev->channels[i].datasheet_name &&
		    strcmp(name, indio_dev->channels[i].datasheet_name) == 0) {
			chan = &indio_dev->channels[i];
			break;
		}
	return chan;
}


struct iio_channel *iio_channel_get(const char *name, const char *channel_name)
{
	struct iio_map_internal *c_i = NULL, *c = NULL;
	struct iio_channel *channel;

	if (name == NULL && channel_name == NULL)
		return ERR_PTR(-ENODEV);

	/* first find matching entry the channel map */
	mutex_lock(&iio_map_list_lock);
	list_for_each_entry(c_i, &iio_map_list, l) {
		if ((name && strcmp(name, c_i->map->consumer_dev_name) != 0) ||
		    (channel_name &&
		     strcmp(channel_name, c_i->map->consumer_channel) != 0))
			continue;
		c = c_i;
		iio_device_get(c->indio_dev);
		break;
	}
	mutex_unlock(&iio_map_list_lock);
	if (c == NULL)
		return ERR_PTR(-ENODEV);

	channel = kmalloc(sizeof(*channel), GFP_KERNEL);
	if (channel == NULL)
		return ERR_PTR(-ENOMEM);

	channel->indio_dev = c->indio_dev;

	if (c->map->adc_channel_label)
		channel->channel =
			iio_chan_spec_from_name(channel->indio_dev,
						c->map->adc_channel_label);

	return channel;
}
EXPORT_SYMBOL_GPL(iio_channel_get);

void iio_channel_release(struct iio_channel *channel)
{
	iio_device_put(channel->indio_dev);
	kfree(channel);
}
EXPORT_SYMBOL_GPL(iio_channel_release);

struct iio_channel *iio_channel_get_all(const char *name)
{
	struct iio_channel *chans;
	struct iio_map_internal *c = NULL;
	int nummaps = 0;
	int mapind = 0;
	int i, ret;

	if (name == NULL)
		return ERR_PTR(-EINVAL);

	mutex_lock(&iio_map_list_lock);
	/* first count the matching maps */
	list_for_each_entry(c, &iio_map_list, l)
		if (name && strcmp(name, c->map->consumer_dev_name) != 0)
			continue;
		else
			nummaps++;

	if (nummaps == 0) {
		ret = -ENODEV;
		goto error_ret;
	}

	/* NULL terminated array to save passing size */
	chans = kzalloc(sizeof(*chans)*(nummaps + 1), GFP_KERNEL);
	if (chans == NULL) {
		ret = -ENOMEM;
		goto error_ret;
	}

	/* for each map fill in the chans element */
	list_for_each_entry(c, &iio_map_list, l) {
		if (name && strcmp(name, c->map->consumer_dev_name) != 0)
			continue;
		chans[mapind].indio_dev = c->indio_dev;
		chans[mapind].channel =
			iio_chan_spec_from_name(chans[mapind].indio_dev,
						c->map->adc_channel_label);
		if (chans[mapind].channel == NULL) {
			ret = -EINVAL;
			iio_device_put(chans[mapind].indio_dev);
			goto error_free_chans;
		}
		iio_device_get(chans[mapind].indio_dev);
		mapind++;
	}
	mutex_unlock(&iio_map_list_lock);
	if (mapind == 0) {
		ret = -ENODEV;
		goto error_free_chans;
	}
	return chans;

error_free_chans:
	for (i = 0; i < nummaps; i++)
		iio_device_put(chans[i].indio_dev);
	kfree(chans);
error_ret:
	mutex_unlock(&iio_map_list_lock);

	return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(iio_channel_get_all);

void iio_channel_release_all(struct iio_channel *channels)
{
	struct iio_channel *chan = &channels[0];

	while (chan->indio_dev) {
		iio_device_put(chan->indio_dev);
		chan++;
	}
	kfree(channels);
}
EXPORT_SYMBOL_GPL(iio_channel_release_all);

int iio_read_channel_raw(struct iio_channel *chan, int *val)
{
	int val2, ret;

	mutex_lock(&chan->indio_dev->info_exist_lock);
	if (chan->indio_dev->info == NULL) {
		ret = -ENODEV;
		goto err_unlock;
	}

	ret = chan->indio_dev->info->read_raw(chan->indio_dev, chan->channel,
					      val, &val2, 0);
err_unlock:
	mutex_unlock(&chan->indio_dev->info_exist_lock);

	return ret;
}
EXPORT_SYMBOL_GPL(iio_read_channel_raw);

int iio_read_channel_scale(struct iio_channel *chan, int *val, int *val2)
{
	int ret;

	mutex_lock(&chan->indio_dev->info_exist_lock);
	if (chan->indio_dev->info == NULL) {
		ret = -ENODEV;
		goto err_unlock;
	}

	ret = chan->indio_dev->info->read_raw(chan->indio_dev,
					      chan->channel,
					      val, val2,
					      IIO_CHAN_INFO_SCALE);
err_unlock:
	mutex_unlock(&chan->indio_dev->info_exist_lock);

	return ret;
}
EXPORT_SYMBOL_GPL(iio_read_channel_scale);

int iio_get_channel_type(struct iio_channel *chan, enum iio_chan_type *type)
{
	int ret = 0;
	/* Need to verify underlying driver has not gone away */

	mutex_lock(&chan->indio_dev->info_exist_lock);
	if (chan->indio_dev->info == NULL) {
		ret = -ENODEV;
		goto err_unlock;
	}

	*type = chan->channel->type;
err_unlock:
	mutex_unlock(&chan->indio_dev->info_exist_lock);

	return ret;
}
EXPORT_SYMBOL_GPL(iio_get_channel_type);