1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18#include <linux/module.h>
19#include <linux/mutex.h>
20#include <linux/init.h>
21#include <linux/i2c.h>
22#include <linux/iio/iio.h>
23
24#define AMS_IAQCORE_DATA_SIZE 9
25
26#define AMS_IAQCORE_VOC_CO2_IDX 0
27#define AMS_IAQCORE_VOC_RESISTANCE_IDX 1
28#define AMS_IAQCORE_VOC_TVOC_IDX 2
29
30struct ams_iaqcore_reading {
31 __be16 co2_ppm;
32 u8 status;
33 __be32 resistance;
34 __be16 voc_ppb;
35} __attribute__((__packed__));
36
37struct ams_iaqcore_data {
38 struct i2c_client *client;
39 struct mutex lock;
40 unsigned long last_update;
41
42 struct ams_iaqcore_reading buffer;
43};
44
45static const struct iio_chan_spec ams_iaqcore_channels[] = {
46 {
47 .type = IIO_CONCENTRATION,
48 .channel2 = IIO_MOD_CO2,
49 .modified = 1,
50 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
51 .address = AMS_IAQCORE_VOC_CO2_IDX,
52 },
53 {
54 .type = IIO_RESISTANCE,
55 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
56 .address = AMS_IAQCORE_VOC_RESISTANCE_IDX,
57 },
58 {
59 .type = IIO_CONCENTRATION,
60 .channel2 = IIO_MOD_VOC,
61 .modified = 1,
62 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
63 .address = AMS_IAQCORE_VOC_TVOC_IDX,
64 },
65};
66
67static int ams_iaqcore_read_measurement(struct ams_iaqcore_data *data)
68{
69 struct i2c_client *client = data->client;
70 int ret;
71
72 struct i2c_msg msg = {
73 .addr = client->addr,
74 .flags = client->flags | I2C_M_RD,
75 .len = AMS_IAQCORE_DATA_SIZE,
76 .buf = (char *) &data->buffer,
77 };
78
79 ret = i2c_transfer(client->adapter, &msg, 1);
80
81 return (ret == AMS_IAQCORE_DATA_SIZE) ? 0 : ret;
82}
83
84static int ams_iaqcore_get_measurement(struct ams_iaqcore_data *data)
85{
86 int ret;
87
88
89 if (!time_after(jiffies, data->last_update + HZ))
90 return 0;
91
92 ret = ams_iaqcore_read_measurement(data);
93 if (ret < 0)
94 return ret;
95
96 data->last_update = jiffies;
97
98 return 0;
99}
100
101static int ams_iaqcore_read_raw(struct iio_dev *indio_dev,
102 struct iio_chan_spec const *chan, int *val,
103 int *val2, long mask)
104{
105 struct ams_iaqcore_data *data = iio_priv(indio_dev);
106 int ret;
107
108 if (mask != IIO_CHAN_INFO_PROCESSED)
109 return -EINVAL;
110
111 mutex_lock(&data->lock);
112 ret = ams_iaqcore_get_measurement(data);
113
114 if (ret)
115 goto err_out;
116
117 switch (chan->address) {
118 case AMS_IAQCORE_VOC_CO2_IDX:
119 *val = 0;
120 *val2 = be16_to_cpu(data->buffer.co2_ppm);
121 ret = IIO_VAL_INT_PLUS_MICRO;
122 break;
123 case AMS_IAQCORE_VOC_RESISTANCE_IDX:
124 *val = be32_to_cpu(data->buffer.resistance);
125 ret = IIO_VAL_INT;
126 break;
127 case AMS_IAQCORE_VOC_TVOC_IDX:
128 *val = 0;
129 *val2 = be16_to_cpu(data->buffer.voc_ppb);
130 ret = IIO_VAL_INT_PLUS_NANO;
131 break;
132 default:
133 ret = -EINVAL;
134 }
135
136err_out:
137 mutex_unlock(&data->lock);
138
139 return ret;
140}
141
142static const struct iio_info ams_iaqcore_info = {
143 .read_raw = ams_iaqcore_read_raw,
144 .driver_module = THIS_MODULE,
145};
146
147static int ams_iaqcore_probe(struct i2c_client *client,
148 const struct i2c_device_id *id)
149{
150 struct iio_dev *indio_dev;
151 struct ams_iaqcore_data *data;
152
153 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
154 if (!indio_dev)
155 return -ENOMEM;
156
157 data = iio_priv(indio_dev);
158 i2c_set_clientdata(client, indio_dev);
159 data->client = client;
160
161
162 data->last_update = jiffies - HZ;
163 mutex_init(&data->lock);
164
165 indio_dev->dev.parent = &client->dev;
166 indio_dev->info = &ams_iaqcore_info;
167 indio_dev->name = dev_name(&client->dev);
168 indio_dev->modes = INDIO_DIRECT_MODE;
169
170 indio_dev->channels = ams_iaqcore_channels;
171 indio_dev->num_channels = ARRAY_SIZE(ams_iaqcore_channels);
172
173 return devm_iio_device_register(&client->dev, indio_dev);
174}
175
176static const struct i2c_device_id ams_iaqcore_id[] = {
177 { "ams-iaq-core", 0 },
178 { }
179};
180MODULE_DEVICE_TABLE(i2c, ams_iaqcore_id);
181
182static const struct of_device_id ams_iaqcore_dt_ids[] = {
183 { .compatible = "ams,iaq-core" },
184 { }
185};
186MODULE_DEVICE_TABLE(of, ams_iaqcore_dt_ids);
187
188static struct i2c_driver ams_iaqcore_driver = {
189 .driver = {
190 .name = "ams-iaq-core",
191 .of_match_table = of_match_ptr(ams_iaqcore_dt_ids),
192 },
193 .probe = ams_iaqcore_probe,
194 .id_table = ams_iaqcore_id,
195};
196module_i2c_driver(ams_iaqcore_driver);
197
198MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
199MODULE_DESCRIPTION("AMS iAQ-Core VOC sensors");
200MODULE_LICENSE("GPL v2");
201
