summaryrefslogtreecommitdiff
path: root/drivers/iio/chemical/atlas-ezo-sensor.c
blob: 761a853a4d17e5cd0eda956d91edd2ce36476e24 (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
// SPDX-License-Identifier: GPL-2.0+
/*
 * atlas-ezo-sensor.c - Support for Atlas Scientific EZO sensors
 *
 * Copyright (C) 2020 Konsulko Group
 * Author: Matt Ranostay <matt.ranostay@konsulko.com>
 */

#include <linux/init.h>
#include <linux/delay.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/property.h>
#include <linux/err.h>
#include <linux/i2c.h>

#include <linux/iio/iio.h>

#define ATLAS_EZO_DRV_NAME		"atlas-ezo-sensor"
#define ATLAS_INT_TIME_IN_MS		950
#define ATLAS_INT_HUM_TIME_IN_MS	350

enum {
	ATLAS_CO2_EZO,
	ATLAS_O2_EZO,
	ATLAS_HUM_EZO,
};

struct atlas_ezo_device {
	const struct iio_chan_spec *channels;
	int num_channels;
	int delay;
};

struct atlas_ezo_data {
	struct i2c_client *client;
	const struct atlas_ezo_device *chip;

	/* lock to avoid multiple concurrent read calls */
	struct mutex lock;

	u8 buffer[8];
};

#define ATLAS_CONCENTRATION_CHANNEL(_modifier) \
	{ \
		.type = IIO_CONCENTRATION, \
		.modified = 1,\
		.channel2 = _modifier, \
		.info_mask_separate = \
			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), \
		.scan_index = 0, \
		.scan_type =  { \
			.sign = 'u', \
			.realbits = 32, \
			.storagebits = 32, \
			.endianness = IIO_CPU, \
		}, \
	}

static const struct iio_chan_spec atlas_co2_ezo_channels[] = {
	ATLAS_CONCENTRATION_CHANNEL(IIO_MOD_CO2),
};

static const struct iio_chan_spec atlas_o2_ezo_channels[] = {
	ATLAS_CONCENTRATION_CHANNEL(IIO_MOD_O2),
};

static const struct iio_chan_spec atlas_hum_ezo_channels[] = {
	{
		.type = IIO_HUMIDITYRELATIVE,
		.info_mask_separate =
			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
		.scan_index = 0,
		.scan_type =  {
			.sign = 'u',
			.realbits = 32,
			.storagebits = 32,
			.endianness = IIO_CPU,
		},
	},
};

static struct atlas_ezo_device atlas_ezo_devices[] = {
	[ATLAS_CO2_EZO] = {
		.channels = atlas_co2_ezo_channels,
		.num_channels = 1,
		.delay = ATLAS_INT_TIME_IN_MS,
	},
	[ATLAS_O2_EZO] = {
		.channels = atlas_o2_ezo_channels,
		.num_channels = 1,
		.delay = ATLAS_INT_TIME_IN_MS,
	},
	[ATLAS_HUM_EZO] = {
		.channels = atlas_hum_ezo_channels,
		.num_channels = 1,
		.delay = ATLAS_INT_HUM_TIME_IN_MS,
	},
};

static void atlas_ezo_sanitize(char *buf)
{
	char *ptr = strchr(buf, '.');

	if (!ptr)
		return;

	memmove(ptr, ptr + 1, strlen(ptr));
}

static int atlas_ezo_read_raw(struct iio_dev *indio_dev,
			  struct iio_chan_spec const *chan,
			  int *val, int *val2, long mask)
{
	struct atlas_ezo_data *data = iio_priv(indio_dev);
	struct i2c_client *client = data->client;

	if (chan->type != IIO_CONCENTRATION)
		return -EINVAL;

	switch (mask) {
	case IIO_CHAN_INFO_RAW: {
		int ret;
		long tmp;

		mutex_lock(&data->lock);

		tmp = i2c_smbus_write_byte(client, 'R');

		if (tmp < 0) {
			mutex_unlock(&data->lock);
			return tmp;
		}

		msleep(data->chip->delay);

		tmp = i2c_master_recv(client, data->buffer, sizeof(data->buffer));

		if (tmp < 0 || data->buffer[0] != 1) {
			mutex_unlock(&data->lock);
			return -EBUSY;
		}

		/* removing floating point for fixed number representation */
		atlas_ezo_sanitize(data->buffer + 2);

		ret = kstrtol(data->buffer + 1, 10, &tmp);

		*val = tmp;

		mutex_unlock(&data->lock);

		return ret ? ret : IIO_VAL_INT;
	}
	case IIO_CHAN_INFO_SCALE:
		switch (chan->type) {
		case IIO_HUMIDITYRELATIVE:
			*val = 10;
			return IIO_VAL_INT;
		case IIO_CONCENTRATION:
			break;
		default:
			return -EINVAL;
		}

		/* IIO_CONCENTRATION modifiers */
		switch (chan->channel2) {
		case IIO_MOD_CO2:
			*val = 0;
			*val2 = 100; /* 0.0001 */
			return IIO_VAL_INT_PLUS_MICRO;
		case IIO_MOD_O2:
			*val = 100;
			return IIO_VAL_INT;
		}
		return -EINVAL;
	}

	return 0;
}

static const struct iio_info atlas_info = {
	.read_raw = atlas_ezo_read_raw,
};

static const struct i2c_device_id atlas_ezo_id[] = {
	{ "atlas-co2-ezo", (kernel_ulong_t)&atlas_ezo_devices[ATLAS_CO2_EZO] },
	{ "atlas-o2-ezo", (kernel_ulong_t)&atlas_ezo_devices[ATLAS_O2_EZO] },
	{ "atlas-hum-ezo", (kernel_ulong_t)&atlas_ezo_devices[ATLAS_HUM_EZO] },
	{}
};
MODULE_DEVICE_TABLE(i2c, atlas_ezo_id);

static const struct of_device_id atlas_ezo_dt_ids[] = {
	{ .compatible = "atlas,co2-ezo", .data = &atlas_ezo_devices[ATLAS_CO2_EZO], },
	{ .compatible = "atlas,o2-ezo", .data = &atlas_ezo_devices[ATLAS_O2_EZO], },
	{ .compatible = "atlas,hum-ezo", .data = &atlas_ezo_devices[ATLAS_HUM_EZO], },
	{}
};
MODULE_DEVICE_TABLE(of, atlas_ezo_dt_ids);

static int atlas_ezo_probe(struct i2c_client *client)
{
	const struct atlas_ezo_device *chip;
	struct atlas_ezo_data *data;
	struct iio_dev *indio_dev;

	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
	if (!indio_dev)
		return -ENOMEM;

	chip = i2c_get_match_data(client);
	if (!chip)
		return -EINVAL;

	indio_dev->info = &atlas_info;
	indio_dev->name = ATLAS_EZO_DRV_NAME;
	indio_dev->channels = chip->channels;
	indio_dev->num_channels = chip->num_channels;
	indio_dev->modes = INDIO_DIRECT_MODE;

	data = iio_priv(indio_dev);
	data->client = client;
	data->chip = chip;
	mutex_init(&data->lock);

	return devm_iio_device_register(&client->dev, indio_dev);
};

static struct i2c_driver atlas_ezo_driver = {
	.driver = {
		.name	= ATLAS_EZO_DRV_NAME,
		.of_match_table	= atlas_ezo_dt_ids,
	},
	.probe		= atlas_ezo_probe,
	.id_table	= atlas_ezo_id,
};
module_i2c_driver(atlas_ezo_driver);

MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
MODULE_DESCRIPTION("Atlas Scientific EZO sensors");
MODULE_LICENSE("GPL");