summaryrefslogtreecommitdiff
path: root/drivers/iio/light/veml6070.c
blob: cfa4e9e7c8038395a9183c3687600deef9a9ed69 (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
// SPDX-License-Identifier: GPL-2.0-only
/*
 * veml6070.c - Support for Vishay VEML6070 UV A light sensor
 *
 * Copyright 2016 Peter Meerwald-Stadler <pmeerw@pmeerw.net>
 *
 * IIO driver for VEML6070 (7-bit I2C slave addresses 0x38 and 0x39)
 *
 * TODO: integration time, ACK signal
 */

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

#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>

#define VEML6070_DRV_NAME "veml6070"

#define VEML6070_ADDR_CONFIG_DATA_MSB 0x38 /* read: MSB data, write: config */
#define VEML6070_ADDR_DATA_LSB	0x39 /* LSB data */

#define VEML6070_COMMAND_ACK	BIT(5) /* raise interrupt when over threshold */
#define VEML6070_COMMAND_IT	GENMASK(3, 2) /* bit mask integration time */
#define VEML6070_COMMAND_RSRVD	BIT(1) /* reserved, set to 1 */
#define VEML6070_COMMAND_SD	BIT(0) /* shutdown mode when set */

#define VEML6070_IT_10	0x04 /* integration time 1x */

struct veml6070_data {
	struct i2c_client *client1;
	struct i2c_client *client2;
	u8 config;
	struct mutex lock;
};

static int veml6070_read(struct veml6070_data *data)
{
	int ret;
	u8 msb, lsb;

	mutex_lock(&data->lock);

	/* disable shutdown */
	ret = i2c_smbus_write_byte(data->client1,
	    data->config & ~VEML6070_COMMAND_SD);
	if (ret < 0)
		goto out;

	msleep(125 + 10); /* measurement takes up to 125 ms for IT 1x */

	ret = i2c_smbus_read_byte(data->client2); /* read MSB, address 0x39 */
	if (ret < 0)
		goto out;
	msb = ret;

	ret = i2c_smbus_read_byte(data->client1); /* read LSB, address 0x38 */
	if (ret < 0)
		goto out;
	lsb = ret;

	/* shutdown again */
	ret = i2c_smbus_write_byte(data->client1, data->config);
	if (ret < 0)
		goto out;

	ret = (msb << 8) | lsb;

out:
	mutex_unlock(&data->lock);
	return ret;
}

static const struct iio_chan_spec veml6070_channels[] = {
	{
		.type = IIO_INTENSITY,
		.modified = 1,
		.channel2 = IIO_MOD_LIGHT_UV,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
	},
	{
		.type = IIO_UVINDEX,
		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
	}
};

static int veml6070_to_uv_index(unsigned val)
{
	/*
	 * conversion of raw UV intensity values to UV index depends on
	 * integration time (IT) and value of the resistor connected to
	 * the RSET pin (default: 270 KOhm)
	 */
	unsigned uvi[11] = {
		187, 373, 560, /* low */
		746, 933, 1120, /* moderate */
		1308, 1494, /* high */
		1681, 1868, 2054}; /* very high */
	int i;

	for (i = 0; i < ARRAY_SIZE(uvi); i++)
		if (val <= uvi[i])
			return i;

	return 11; /* extreme */
}

static int veml6070_read_raw(struct iio_dev *indio_dev,
				struct iio_chan_spec const *chan,
				int *val, int *val2, long mask)
{
	struct veml6070_data *data = iio_priv(indio_dev);
	int ret;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
	case IIO_CHAN_INFO_PROCESSED:
		ret = veml6070_read(data);
		if (ret < 0)
			return ret;
		if (mask == IIO_CHAN_INFO_PROCESSED)
			*val = veml6070_to_uv_index(ret);
		else
			*val = ret;
		return IIO_VAL_INT;
	default:
		return -EINVAL;
	}
}

static const struct iio_info veml6070_info = {
	.read_raw = veml6070_read_raw,
};

static int veml6070_probe(struct i2c_client *client,
			  const struct i2c_device_id *id)
{
	struct veml6070_data *data;
	struct iio_dev *indio_dev;
	int ret;

	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->client1 = client;
	mutex_init(&data->lock);

	indio_dev->info = &veml6070_info;
	indio_dev->channels = veml6070_channels;
	indio_dev->num_channels = ARRAY_SIZE(veml6070_channels);
	indio_dev->name = VEML6070_DRV_NAME;
	indio_dev->modes = INDIO_DIRECT_MODE;

	data->client2 = i2c_new_dummy_device(client->adapter, VEML6070_ADDR_DATA_LSB);
	if (IS_ERR(data->client2)) {
		dev_err(&client->dev, "i2c device for second chip address failed\n");
		return PTR_ERR(data->client2);
	}

	data->config = VEML6070_IT_10 | VEML6070_COMMAND_RSRVD |
		VEML6070_COMMAND_SD;
	ret = i2c_smbus_write_byte(data->client1, data->config);
	if (ret < 0)
		goto fail;

	ret = iio_device_register(indio_dev);
	if (ret < 0)
		goto fail;

	return ret;

fail:
	i2c_unregister_device(data->client2);
	return ret;
}

static void veml6070_remove(struct i2c_client *client)
{
	struct iio_dev *indio_dev = i2c_get_clientdata(client);
	struct veml6070_data *data = iio_priv(indio_dev);

	iio_device_unregister(indio_dev);
	i2c_unregister_device(data->client2);
}

static const struct i2c_device_id veml6070_id[] = {
	{ "veml6070", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, veml6070_id);

static struct i2c_driver veml6070_driver = {
	.driver = {
		.name   = VEML6070_DRV_NAME,
	},
	.probe  = veml6070_probe,
	.remove  = veml6070_remove,
	.id_table = veml6070_id,
};

module_i2c_driver(veml6070_driver);

MODULE_AUTHOR("Peter Meerwald-Stadler <pmeerw@pmeerw.net>");
MODULE_DESCRIPTION("Vishay VEML6070 UV A light sensor driver");
MODULE_LICENSE("GPL");