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
|
/*
* ams-iaq-core.c - Support for AMS iAQ-Core VOC sensors
*
* Copyright (C) 2015 Matt Ranostay <mranostay@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/iio/iio.h>
#define AMS_IAQCORE_DATA_SIZE 9
#define AMS_IAQCORE_VOC_CO2_IDX 0
#define AMS_IAQCORE_VOC_RESISTANCE_IDX 1
#define AMS_IAQCORE_VOC_TVOC_IDX 2
struct ams_iaqcore_reading {
__be16 co2_ppm;
u8 status;
__be32 resistance;
__be16 voc_ppb;
} __attribute__((__packed__));
struct ams_iaqcore_data {
struct i2c_client *client;
struct mutex lock;
unsigned long last_update;
struct ams_iaqcore_reading buffer;
};
static const struct iio_chan_spec ams_iaqcore_channels[] = {
{
.type = IIO_CONCENTRATION,
.channel2 = IIO_MOD_CO2,
.modified = 1,
.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
.address = AMS_IAQCORE_VOC_CO2_IDX,
},
{
.type = IIO_RESISTANCE,
.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
.address = AMS_IAQCORE_VOC_RESISTANCE_IDX,
},
{
.type = IIO_CONCENTRATION,
.channel2 = IIO_MOD_VOC,
.modified = 1,
.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
.address = AMS_IAQCORE_VOC_TVOC_IDX,
},
};
static int ams_iaqcore_read_measurement(struct ams_iaqcore_data *data)
{
struct i2c_client *client = data->client;
int ret;
struct i2c_msg msg = {
.addr = client->addr,
.flags = client->flags | I2C_M_RD,
.len = AMS_IAQCORE_DATA_SIZE,
.buf = (char *) &data->buffer,
};
ret = i2c_transfer(client->adapter, &msg, 1);
return (ret == AMS_IAQCORE_DATA_SIZE) ? 0 : ret;
}
static int ams_iaqcore_get_measurement(struct ams_iaqcore_data *data)
{
int ret;
/* sensor can only be polled once a second max per datasheet */
if (!time_after(jiffies, data->last_update + HZ))
return 0;
ret = ams_iaqcore_read_measurement(data);
if (ret < 0)
return ret;
data->last_update = jiffies;
return 0;
}
static int ams_iaqcore_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int *val,
int *val2, long mask)
{
struct ams_iaqcore_data *data = iio_priv(indio_dev);
int ret;
if (mask != IIO_CHAN_INFO_PROCESSED)
return -EINVAL;
mutex_lock(&data->lock);
ret = ams_iaqcore_get_measurement(data);
if (ret)
goto err_out;
switch (chan->address) {
case AMS_IAQCORE_VOC_CO2_IDX:
*val = 0;
*val2 = be16_to_cpu(data->buffer.co2_ppm);
ret = IIO_VAL_INT_PLUS_MICRO;
break;
case AMS_IAQCORE_VOC_RESISTANCE_IDX:
*val = be32_to_cpu(data->buffer.resistance);
ret = IIO_VAL_INT;
break;
case AMS_IAQCORE_VOC_TVOC_IDX:
*val = 0;
*val2 = be16_to_cpu(data->buffer.voc_ppb);
ret = IIO_VAL_INT_PLUS_NANO;
break;
default:
ret = -EINVAL;
}
err_out:
mutex_unlock(&data->lock);
return ret;
}
static const struct iio_info ams_iaqcore_info = {
.read_raw = ams_iaqcore_read_raw,
.driver_module = THIS_MODULE,
};
static int ams_iaqcore_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct iio_dev *indio_dev;
struct ams_iaqcore_data *data;
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
if (!indio_dev)
return -ENOMEM;
data = iio_priv(indio_dev);
i2c_set_clientdata(client, indio_dev);
data->client = client;
/* so initial reading will complete */
data->last_update = jiffies - HZ;
mutex_init(&data->lock);
indio_dev->dev.parent = &client->dev;
indio_dev->info = &ams_iaqcore_info;
indio_dev->name = dev_name(&client->dev);
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = ams_iaqcore_channels;
indio_dev->num_channels = ARRAY_SIZE(ams_iaqcore_channels);
return devm_iio_device_register(&client->dev, indio_dev);
}
static const struct i2c_device_id ams_iaqcore_id[] = {
{ "ams-iaq-core", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, ams_iaqcore_id);
static const struct of_device_id ams_iaqcore_dt_ids[] = {
{ .compatible = "ams,iaq-core" },
{ }
};
MODULE_DEVICE_TABLE(of, ams_iaqcore_dt_ids);
static struct i2c_driver ams_iaqcore_driver = {
.driver = {
.name = "ams-iaq-core",
.of_match_table = of_match_ptr(ams_iaqcore_dt_ids),
},
.probe = ams_iaqcore_probe,
.id_table = ams_iaqcore_id,
};
module_i2c_driver(ams_iaqcore_driver);
MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
MODULE_DESCRIPTION("AMS iAQ-Core VOC sensors");
MODULE_LICENSE("GPL v2");
|
