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1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * tmp006.c - Support for TI TMP006 IR thermopile sensor
4  *
5  * Copyright (c) 2013 Peter Meerwald <pmeerw@pmeerw.net>
6  *
7  * Driver for the Texas Instruments I2C 16-bit IR thermopile sensor
8  *
9  * (7-bit I2C slave address 0x40, changeable via ADR pins)
10  *
11  * TODO: data ready irq
12  */
13 
14 #include <linux/err.h>
15 #include <linux/i2c.h>
16 #include <linux/delay.h>
17 #include <linux/module.h>
18 #include <linux/pm.h>
19 #include <linux/bitops.h>
20 
21 #include <linux/iio/iio.h>
22 #include <linux/iio/sysfs.h>
23 
24 #define TMP006_VOBJECT 0x00
25 #define TMP006_TAMBIENT 0x01
26 #define TMP006_CONFIG 0x02
27 #define TMP006_MANUFACTURER_ID 0xfe
28 #define TMP006_DEVICE_ID 0xff
29 
30 #define TMP006_TAMBIENT_SHIFT 2
31 
32 #define TMP006_CONFIG_RESET BIT(15)
33 #define TMP006_CONFIG_DRDY_EN BIT(8)
34 #define TMP006_CONFIG_DRDY BIT(7)
35 
36 #define TMP006_CONFIG_MOD_MASK GENMASK(14, 12)
37 
38 #define TMP006_CONFIG_CR_MASK GENMASK(11, 9)
39 #define TMP006_CONFIG_CR_SHIFT 9
40 
41 #define TMP006_MANUFACTURER_MAGIC 0x5449
42 #define TMP006_DEVICE_MAGIC 0x0067
43 
44 struct tmp006_data {
45 	struct i2c_client *client;
46 	u16 config;
47 };
48 
tmp006_read_measurement(struct tmp006_data * data,u8 reg)49 static int tmp006_read_measurement(struct tmp006_data *data, u8 reg)
50 {
51 	s32 ret;
52 	int tries = 50;
53 
54 	while (tries-- > 0) {
55 		ret = i2c_smbus_read_word_swapped(data->client,
56 			TMP006_CONFIG);
57 		if (ret < 0)
58 			return ret;
59 		if (ret & TMP006_CONFIG_DRDY)
60 			break;
61 		msleep(100);
62 	}
63 
64 	if (tries < 0)
65 		return -EIO;
66 
67 	return i2c_smbus_read_word_swapped(data->client, reg);
68 }
69 
70 static const int tmp006_freqs[5][2] = { {4, 0}, {2, 0}, {1, 0},
71 					{0, 500000}, {0, 250000} };
72 
tmp006_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * channel,int * val,int * val2,long mask)73 static int tmp006_read_raw(struct iio_dev *indio_dev,
74 			    struct iio_chan_spec const *channel, int *val,
75 			    int *val2, long mask)
76 {
77 	struct tmp006_data *data = iio_priv(indio_dev);
78 	s32 ret;
79 	int cr;
80 
81 	switch (mask) {
82 	case IIO_CHAN_INFO_RAW:
83 		if (channel->type == IIO_VOLTAGE) {
84 			/* LSB is 156.25 nV */
85 			ret = tmp006_read_measurement(data, TMP006_VOBJECT);
86 			if (ret < 0)
87 				return ret;
88 			*val = sign_extend32(ret, 15);
89 		} else if (channel->type == IIO_TEMP) {
90 			/* LSB is 0.03125 degrees Celsius */
91 			ret = tmp006_read_measurement(data, TMP006_TAMBIENT);
92 			if (ret < 0)
93 				return ret;
94 			*val = sign_extend32(ret, 15) >> TMP006_TAMBIENT_SHIFT;
95 		} else {
96 			break;
97 		}
98 		return IIO_VAL_INT;
99 	case IIO_CHAN_INFO_SCALE:
100 		if (channel->type == IIO_VOLTAGE) {
101 			*val = 0;
102 			*val2 = 156250;
103 		} else if (channel->type == IIO_TEMP) {
104 			*val = 31;
105 			*val2 = 250000;
106 		} else {
107 			break;
108 		}
109 		return IIO_VAL_INT_PLUS_MICRO;
110 	case IIO_CHAN_INFO_SAMP_FREQ:
111 		cr = (data->config & TMP006_CONFIG_CR_MASK)
112 			>> TMP006_CONFIG_CR_SHIFT;
113 		*val = tmp006_freqs[cr][0];
114 		*val2 = tmp006_freqs[cr][1];
115 		return IIO_VAL_INT_PLUS_MICRO;
116 	default:
117 		break;
118 	}
119 
120 	return -EINVAL;
121 }
122 
tmp006_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)123 static int tmp006_write_raw(struct iio_dev *indio_dev,
124 			    struct iio_chan_spec const *chan,
125 			    int val,
126 			    int val2,
127 			    long mask)
128 {
129 	struct tmp006_data *data = iio_priv(indio_dev);
130 	int i;
131 
132 	if (mask != IIO_CHAN_INFO_SAMP_FREQ)
133 		return -EINVAL;
134 
135 	for (i = 0; i < ARRAY_SIZE(tmp006_freqs); i++)
136 		if ((val == tmp006_freqs[i][0]) &&
137 		    (val2 == tmp006_freqs[i][1])) {
138 			data->config &= ~TMP006_CONFIG_CR_MASK;
139 			data->config |= i << TMP006_CONFIG_CR_SHIFT;
140 
141 			return i2c_smbus_write_word_swapped(data->client,
142 							    TMP006_CONFIG,
143 							    data->config);
144 
145 		}
146 	return -EINVAL;
147 }
148 
149 static IIO_CONST_ATTR(sampling_frequency_available, "4 2 1 0.5 0.25");
150 
151 static struct attribute *tmp006_attributes[] = {
152 	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
153 	NULL
154 };
155 
156 static const struct attribute_group tmp006_attribute_group = {
157 	.attrs = tmp006_attributes,
158 };
159 
160 static const struct iio_chan_spec tmp006_channels[] = {
161 	{
162 		.type = IIO_VOLTAGE,
163 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
164 			BIT(IIO_CHAN_INFO_SCALE),
165 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
166 	},
167 	{
168 		.type = IIO_TEMP,
169 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
170 			BIT(IIO_CHAN_INFO_SCALE),
171 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
172 	}
173 };
174 
175 static const struct iio_info tmp006_info = {
176 	.read_raw = tmp006_read_raw,
177 	.write_raw = tmp006_write_raw,
178 	.attrs = &tmp006_attribute_group,
179 };
180 
tmp006_check_identification(struct i2c_client * client)181 static bool tmp006_check_identification(struct i2c_client *client)
182 {
183 	int mid, did;
184 
185 	mid = i2c_smbus_read_word_swapped(client, TMP006_MANUFACTURER_ID);
186 	if (mid < 0)
187 		return false;
188 
189 	did = i2c_smbus_read_word_swapped(client, TMP006_DEVICE_ID);
190 	if (did < 0)
191 		return false;
192 
193 	return mid == TMP006_MANUFACTURER_MAGIC && did == TMP006_DEVICE_MAGIC;
194 }
195 
tmp006_probe(struct i2c_client * client,const struct i2c_device_id * id)196 static int tmp006_probe(struct i2c_client *client,
197 			 const struct i2c_device_id *id)
198 {
199 	struct iio_dev *indio_dev;
200 	struct tmp006_data *data;
201 	int ret;
202 
203 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
204 		return -EOPNOTSUPP;
205 
206 	if (!tmp006_check_identification(client)) {
207 		dev_err(&client->dev, "no TMP006 sensor\n");
208 		return -ENODEV;
209 	}
210 
211 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
212 	if (!indio_dev)
213 		return -ENOMEM;
214 
215 	data = iio_priv(indio_dev);
216 	i2c_set_clientdata(client, indio_dev);
217 	data->client = client;
218 
219 	indio_dev->name = dev_name(&client->dev);
220 	indio_dev->modes = INDIO_DIRECT_MODE;
221 	indio_dev->info = &tmp006_info;
222 
223 	indio_dev->channels = tmp006_channels;
224 	indio_dev->num_channels = ARRAY_SIZE(tmp006_channels);
225 
226 	ret = i2c_smbus_read_word_swapped(data->client, TMP006_CONFIG);
227 	if (ret < 0)
228 		return ret;
229 	data->config = ret;
230 
231 	return iio_device_register(indio_dev);
232 }
233 
tmp006_powerdown(struct tmp006_data * data)234 static int tmp006_powerdown(struct tmp006_data *data)
235 {
236 	return i2c_smbus_write_word_swapped(data->client, TMP006_CONFIG,
237 		data->config & ~TMP006_CONFIG_MOD_MASK);
238 }
239 
tmp006_remove(struct i2c_client * client)240 static int tmp006_remove(struct i2c_client *client)
241 {
242 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
243 
244 	iio_device_unregister(indio_dev);
245 	tmp006_powerdown(iio_priv(indio_dev));
246 
247 	return 0;
248 }
249 
250 #ifdef CONFIG_PM_SLEEP
tmp006_suspend(struct device * dev)251 static int tmp006_suspend(struct device *dev)
252 {
253 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
254 	return tmp006_powerdown(iio_priv(indio_dev));
255 }
256 
tmp006_resume(struct device * dev)257 static int tmp006_resume(struct device *dev)
258 {
259 	struct tmp006_data *data = iio_priv(i2c_get_clientdata(
260 		to_i2c_client(dev)));
261 	return i2c_smbus_write_word_swapped(data->client, TMP006_CONFIG,
262 		data->config | TMP006_CONFIG_MOD_MASK);
263 }
264 #endif
265 
266 static SIMPLE_DEV_PM_OPS(tmp006_pm_ops, tmp006_suspend, tmp006_resume);
267 
268 static const struct i2c_device_id tmp006_id[] = {
269 	{ "tmp006", 0 },
270 	{ }
271 };
272 MODULE_DEVICE_TABLE(i2c, tmp006_id);
273 
274 static struct i2c_driver tmp006_driver = {
275 	.driver = {
276 		.name	= "tmp006",
277 		.pm	= &tmp006_pm_ops,
278 	},
279 	.probe = tmp006_probe,
280 	.remove = tmp006_remove,
281 	.id_table = tmp006_id,
282 };
283 module_i2c_driver(tmp006_driver);
284 
285 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
286 MODULE_DESCRIPTION("TI TMP006 IR thermopile sensor driver");
287 MODULE_LICENSE("GPL");
288