summaryrefslogtreecommitdiffstats
path: root/kernel/drivers/iio/temperature/mlx90614.c
blob: a112fc9abf4346ba0e53b03314fa3781aec9eeac (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
/*
 * mlx90614.c - Support for Melexis MLX90614 contactless IR temperature sensor
 *
 * Copyright (c) 2014 Peter Meerwald <pmeerw@pmeerw.net>
 * Copyright (c) 2015 Essensium NV
 *
 * This file is subject to the terms and conditions of version 2 of
 * the GNU General Public License.  See the file COPYING in the main
 * directory of this archive for more details.
 *
 * Driver for the Melexis MLX90614 I2C 16-bit IR thermopile sensor
 *
 * (7-bit I2C slave address 0x5a, 100KHz bus speed only!)
 *
 * TODO: sleep mode, configuration EEPROM
 */

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

#include <linux/iio/iio.h>

#define MLX90614_OP_RAM		0x00
#define MLX90614_OP_EEPROM	0x20
#define MLX90614_OP_SLEEP	0xff

/* RAM offsets with 16-bit data, MSB first */
#define MLX90614_RAW1	(MLX90614_OP_RAM | 0x04) /* raw data IR channel 1 */
#define MLX90614_RAW2	(MLX90614_OP_RAM | 0x05) /* raw data IR channel 2 */
#define MLX90614_TA	(MLX90614_OP_RAM | 0x06) /* ambient temperature */
#define MLX90614_TOBJ1	(MLX90614_OP_RAM | 0x07) /* object 1 temperature */
#define MLX90614_TOBJ2	(MLX90614_OP_RAM | 0x08) /* object 2 temperature */

/* EEPROM offsets with 16-bit data, MSB first */
#define MLX90614_EMISSIVITY	(MLX90614_OP_EEPROM | 0x04) /* emissivity correction coefficient */
#define MLX90614_CONFIG		(MLX90614_OP_EEPROM | 0x05) /* configuration register */

/* Control bits in configuration register */
#define MLX90614_CONFIG_IIR_SHIFT 0 /* IIR coefficient */
#define MLX90614_CONFIG_IIR_MASK (0x7 << MLX90614_CONFIG_IIR_SHIFT)
#define MLX90614_CONFIG_DUAL_SHIFT 6 /* single (0) or dual (1) IR sensor */
#define MLX90614_CONFIG_DUAL_MASK (1 << MLX90614_CONFIG_DUAL_SHIFT)
#define MLX90614_CONFIG_FIR_SHIFT 8 /* FIR coefficient */
#define MLX90614_CONFIG_FIR_MASK (0x7 << MLX90614_CONFIG_FIR_SHIFT)
#define MLX90614_CONFIG_GAIN_SHIFT 11 /* gain */
#define MLX90614_CONFIG_GAIN_MASK (0x7 << MLX90614_CONFIG_GAIN_SHIFT)

/* Timings (in ms) */
#define MLX90614_TIMING_EEPROM 20 /* time for EEPROM write/erase to complete */
#define MLX90614_TIMING_WAKEUP 34 /* time to hold SDA low for wake-up */
#define MLX90614_TIMING_STARTUP 250 /* time before first data after wake-up */

struct mlx90614_data {
	struct i2c_client *client;
};

static int mlx90614_read_raw(struct iio_dev *indio_dev,
			    struct iio_chan_spec const *channel, int *val,
			    int *val2, long mask)
{
	struct mlx90614_data *data = iio_priv(indio_dev);
	u8 cmd;
	s32 ret;

	switch (mask) {
	case IIO_CHAN_INFO_RAW: /* 0.02K / LSB */
		switch (channel->channel2) {
		case IIO_MOD_TEMP_AMBIENT:
			cmd = MLX90614_TA;
			break;
		case IIO_MOD_TEMP_OBJECT:
			switch (channel->channel) {
			case 0:
				cmd = MLX90614_TOBJ1;
				break;
			case 1:
				cmd = MLX90614_TOBJ2;
				break;
			default:
				return -EINVAL;
			}
			break;
		default:
			return -EINVAL;
		}

		ret = i2c_smbus_read_word_data(data->client, cmd);
		if (ret < 0)
			return ret;
		*val = ret;
		return IIO_VAL_INT;
	case IIO_CHAN_INFO_OFFSET:
		*val = 13657;
		*val2 = 500000;
		return IIO_VAL_INT_PLUS_MICRO;
	case IIO_CHAN_INFO_SCALE:
		*val = 20;
		return IIO_VAL_INT;
	default:
		return -EINVAL;
	}
}

static const struct iio_chan_spec mlx90614_channels[] = {
	{
		.type = IIO_TEMP,
		.modified = 1,
		.channel2 = IIO_MOD_TEMP_AMBIENT,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
		    BIT(IIO_CHAN_INFO_SCALE),
	},
	{
		.type = IIO_TEMP,
		.modified = 1,
		.channel2 = IIO_MOD_TEMP_OBJECT,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
		    BIT(IIO_CHAN_INFO_SCALE),
	},
	{
		.type = IIO_TEMP,
		.indexed = 1,
		.modified = 1,
		.channel = 1,
		.channel2 = IIO_MOD_TEMP_OBJECT,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
		    BIT(IIO_CHAN_INFO_SCALE),
	},
};

static const struct iio_info mlx90614_info = {
	.read_raw = mlx90614_read_raw,
	.driver_module = THIS_MODULE,
};

/* Return 0 for single sensor, 1 for dual sensor, <0 on error. */
static int mlx90614_probe_num_ir_sensors(struct i2c_client *client)
{
	s32 ret;

	ret = i2c_smbus_read_word_data(client, MLX90614_CONFIG);

	if (ret < 0)
		return ret;

	return (ret & MLX90614_CONFIG_DUAL_MASK) ? 1 : 0;
}

static int mlx90614_probe(struct i2c_client *client,
			 const struct i2c_device_id *id)
{
	struct iio_dev *indio_dev;
	struct mlx90614_data *data;
	int ret;

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
		return -ENODEV;

	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;

	indio_dev->dev.parent = &client->dev;
	indio_dev->name = id->name;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->info = &mlx90614_info;

	ret = mlx90614_probe_num_ir_sensors(client);
	switch (ret) {
	case 0:
		dev_dbg(&client->dev, "Found single sensor");
		indio_dev->channels = mlx90614_channels;
		indio_dev->num_channels = 2;
		break;
	case 1:
		dev_dbg(&client->dev, "Found dual sensor");
		indio_dev->channels = mlx90614_channels;
		indio_dev->num_channels = 3;
		break;
	default:
		return ret;
	}

	return iio_device_register(indio_dev);
}

static int mlx90614_remove(struct i2c_client *client)
{
	iio_device_unregister(i2c_get_clientdata(client));

	return 0;
}

static const struct i2c_device_id mlx90614_id[] = {
	{ "mlx90614", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, mlx90614_id);

static struct i2c_driver mlx90614_driver = {
	.driver = {
		.name	= "mlx90614",
		.owner	= THIS_MODULE,
	},
	.probe = mlx90614_probe,
	.remove = mlx90614_remove,
	.id_table = mlx90614_id,
};
module_i2c_driver(mlx90614_driver);

MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
MODULE_AUTHOR("Vianney le Clément de Saint-Marcq <vianney.leclement@essensium.com>");
MODULE_DESCRIPTION("Melexis MLX90614 contactless IR temperature sensor driver");
MODULE_LICENSE("GPL");