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Matt Ranostayd6ad8052018-02-17 21:36:46 -08001// SPDX-License-Identifier: GPL-2.0+
Matt Ranostay466df4d02015-12-05 22:58:22 -08002/*
3 * ams-iaq-core.c - Support for AMS iAQ-Core VOC sensors
4 *
Matt Ranostayd6ad8052018-02-17 21:36:46 -08005 * Copyright (C) 2015, 2018
6 * Author: Matt Ranostay <matt.ranostay@konsulko.com>
Matt Ranostay466df4d02015-12-05 22:58:22 -08007 */
8
9#include <linux/module.h>
10#include <linux/mutex.h>
11#include <linux/init.h>
12#include <linux/i2c.h>
13#include <linux/iio/iio.h>
14
15#define AMS_IAQCORE_DATA_SIZE 9
16
17#define AMS_IAQCORE_VOC_CO2_IDX 0
18#define AMS_IAQCORE_VOC_RESISTANCE_IDX 1
19#define AMS_IAQCORE_VOC_TVOC_IDX 2
20
21struct ams_iaqcore_reading {
22 __be16 co2_ppm;
23 u8 status;
24 __be32 resistance;
25 __be16 voc_ppb;
26} __attribute__((__packed__));
27
28struct ams_iaqcore_data {
29 struct i2c_client *client;
30 struct mutex lock;
31 unsigned long last_update;
32
33 struct ams_iaqcore_reading buffer;
34};
35
36static const struct iio_chan_spec ams_iaqcore_channels[] = {
37 {
38 .type = IIO_CONCENTRATION,
39 .channel2 = IIO_MOD_CO2,
40 .modified = 1,
41 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
42 .address = AMS_IAQCORE_VOC_CO2_IDX,
43 },
44 {
45 .type = IIO_RESISTANCE,
46 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
47 .address = AMS_IAQCORE_VOC_RESISTANCE_IDX,
48 },
49 {
50 .type = IIO_CONCENTRATION,
51 .channel2 = IIO_MOD_VOC,
52 .modified = 1,
53 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
54 .address = AMS_IAQCORE_VOC_TVOC_IDX,
55 },
56};
57
58static int ams_iaqcore_read_measurement(struct ams_iaqcore_data *data)
59{
60 struct i2c_client *client = data->client;
61 int ret;
62
63 struct i2c_msg msg = {
64 .addr = client->addr,
65 .flags = client->flags | I2C_M_RD,
66 .len = AMS_IAQCORE_DATA_SIZE,
67 .buf = (char *) &data->buffer,
68 };
69
70 ret = i2c_transfer(client->adapter, &msg, 1);
71
72 return (ret == AMS_IAQCORE_DATA_SIZE) ? 0 : ret;
73}
74
75static int ams_iaqcore_get_measurement(struct ams_iaqcore_data *data)
76{
77 int ret;
78
79 /* sensor can only be polled once a second max per datasheet */
80 if (!time_after(jiffies, data->last_update + HZ))
81 return 0;
82
83 ret = ams_iaqcore_read_measurement(data);
84 if (ret < 0)
85 return ret;
86
87 data->last_update = jiffies;
88
89 return 0;
90}
91
92static int ams_iaqcore_read_raw(struct iio_dev *indio_dev,
93 struct iio_chan_spec const *chan, int *val,
94 int *val2, long mask)
95{
96 struct ams_iaqcore_data *data = iio_priv(indio_dev);
97 int ret;
98
99 if (mask != IIO_CHAN_INFO_PROCESSED)
100 return -EINVAL;
101
102 mutex_lock(&data->lock);
103 ret = ams_iaqcore_get_measurement(data);
104
105 if (ret)
106 goto err_out;
107
108 switch (chan->address) {
109 case AMS_IAQCORE_VOC_CO2_IDX:
110 *val = 0;
111 *val2 = be16_to_cpu(data->buffer.co2_ppm);
112 ret = IIO_VAL_INT_PLUS_MICRO;
113 break;
114 case AMS_IAQCORE_VOC_RESISTANCE_IDX:
115 *val = be32_to_cpu(data->buffer.resistance);
116 ret = IIO_VAL_INT;
117 break;
118 case AMS_IAQCORE_VOC_TVOC_IDX:
119 *val = 0;
120 *val2 = be16_to_cpu(data->buffer.voc_ppb);
121 ret = IIO_VAL_INT_PLUS_NANO;
122 break;
123 default:
124 ret = -EINVAL;
125 }
126
127err_out:
128 mutex_unlock(&data->lock);
129
130 return ret;
131}
132
133static const struct iio_info ams_iaqcore_info = {
134 .read_raw = ams_iaqcore_read_raw,
Matt Ranostay466df4d02015-12-05 22:58:22 -0800135};
136
137static int ams_iaqcore_probe(struct i2c_client *client,
138 const struct i2c_device_id *id)
139{
140 struct iio_dev *indio_dev;
141 struct ams_iaqcore_data *data;
142
143 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
144 if (!indio_dev)
145 return -ENOMEM;
146
147 data = iio_priv(indio_dev);
148 i2c_set_clientdata(client, indio_dev);
149 data->client = client;
150
151 /* so initial reading will complete */
152 data->last_update = jiffies - HZ;
153 mutex_init(&data->lock);
154
155 indio_dev->dev.parent = &client->dev;
Arushi Singhal5e13b6f2017-03-30 18:11:22 +0530156 indio_dev->info = &ams_iaqcore_info;
Matt Ranostay466df4d02015-12-05 22:58:22 -0800157 indio_dev->name = dev_name(&client->dev);
158 indio_dev->modes = INDIO_DIRECT_MODE;
159
160 indio_dev->channels = ams_iaqcore_channels;
161 indio_dev->num_channels = ARRAY_SIZE(ams_iaqcore_channels);
162
163 return devm_iio_device_register(&client->dev, indio_dev);
164}
165
166static const struct i2c_device_id ams_iaqcore_id[] = {
167 { "ams-iaq-core", 0 },
168 { }
169};
170MODULE_DEVICE_TABLE(i2c, ams_iaqcore_id);
171
172static const struct of_device_id ams_iaqcore_dt_ids[] = {
173 { .compatible = "ams,iaq-core" },
174 { }
175};
176MODULE_DEVICE_TABLE(of, ams_iaqcore_dt_ids);
177
178static struct i2c_driver ams_iaqcore_driver = {
179 .driver = {
180 .name = "ams-iaq-core",
181 .of_match_table = of_match_ptr(ams_iaqcore_dt_ids),
182 },
183 .probe = ams_iaqcore_probe,
184 .id_table = ams_iaqcore_id,
185};
186module_i2c_driver(ams_iaqcore_driver);
187
Matt Ranostayd6ad8052018-02-17 21:36:46 -0800188MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
Matt Ranostay466df4d02015-12-05 22:58:22 -0800189MODULE_DESCRIPTION("AMS iAQ-Core VOC sensors");
190MODULE_LICENSE("GPL v2");