1/*
  2 * tmp006.c - Support for TI TMP006 IR thermopile sensor
  3 *
  4 * Copyright (c) 2013 Peter Meerwald <pmeerw@pmeerw.net>
  5 *
  6 * This file is subject to the terms and conditions of version 2 of
  7 * the GNU General Public License.  See the file COPYING in the main
  8 * directory of this archive for more details.
  9 *
 10 * Driver for the Texas Instruments I2C 16-bit IR thermopile sensor
 11 *
 12 * (7-bit I2C slave address 0x40, changeable via ADR pins)
 13 *
 14 * TODO: data ready irq
 15 */
 16
 17#include <linux/err.h>
 18#include <linux/i2c.h>
 19#include <linux/delay.h>
 20#include <linux/module.h>
 21#include <linux/pm.h>
 22#include <linux/bitops.h>
 23
 24#include <linux/iio/iio.h>
 25#include <linux/iio/sysfs.h>
 26
 27#define TMP006_VOBJECT 0x00
 28#define TMP006_TAMBIENT 0x01
 29#define TMP006_CONFIG 0x02
 30#define TMP006_MANUFACTURER_ID 0xfe
 31#define TMP006_DEVICE_ID 0xff
 32
 33#define TMP006_TAMBIENT_SHIFT 2
 34
 35#define TMP006_CONFIG_RESET BIT(15)
 36#define TMP006_CONFIG_DRDY_EN BIT(8)
 37#define TMP006_CONFIG_DRDY BIT(7)
 38
 39#define TMP006_CONFIG_MOD_MASK GENMASK(14, 12)
 40
 41#define TMP006_CONFIG_CR_MASK GENMASK(11, 9)
 42#define TMP006_CONFIG_CR_SHIFT 9
 43
 44#define TMP006_MANUFACTURER_MAGIC 0x5449
 45#define TMP006_DEVICE_MAGIC 0x0067
 46
 47struct tmp006_data {
 48	struct i2c_client *client;
 49	u16 config;
 50};
 51
 52static int tmp006_read_measurement(struct tmp006_data *data, u8 reg)
 53{
 54	s32 ret;
 55	int tries = 50;
 56
 57	while (tries-- > 0) {
 58		ret = i2c_smbus_read_word_swapped(data->client,
 59			TMP006_CONFIG);
 60		if (ret < 0)
 61			return ret;
 62		if (ret & TMP006_CONFIG_DRDY)
 63			break;
 64		msleep(100);
 65	}
 66
 67	if (tries < 0)
 68		return -EIO;
 69
 70	return i2c_smbus_read_word_swapped(data->client, reg);
 71}
 72
 73static const int tmp006_freqs[5][2] = { {4, 0}, {2, 0}, {1, 0},
 74					{0, 500000}, {0, 250000} };
 75
 76static int tmp006_read_raw(struct iio_dev *indio_dev,
 77			    struct iio_chan_spec const *channel, int *val,
 78			    int *val2, long mask)
 79{
 80	struct tmp006_data *data = iio_priv(indio_dev);
 81	s32 ret;
 82	int cr;
 83
 84	switch (mask) {
 85	case IIO_CHAN_INFO_RAW:
 86		if (channel->type == IIO_VOLTAGE) {
 87			/* LSB is 156.25 nV */
 88			ret = tmp006_read_measurement(data, TMP006_VOBJECT);
 89			if (ret < 0)
 90				return ret;
 91			*val = sign_extend32(ret, 15);
 92		} else if (channel->type == IIO_TEMP) {
 93			/* LSB is 0.03125 degrees Celsius */
 94			ret = tmp006_read_measurement(data, TMP006_TAMBIENT);
 95			if (ret < 0)
 96				return ret;
 97			*val = sign_extend32(ret, 15) >> TMP006_TAMBIENT_SHIFT;
 98		} else {
 99			break;
100		}
101		return IIO_VAL_INT;
102	case IIO_CHAN_INFO_SCALE:
103		if (channel->type == IIO_VOLTAGE) {
104			*val = 0;
105			*val2 = 156250;
106		} else if (channel->type == IIO_TEMP) {
107			*val = 31;
108			*val2 = 250000;
109		} else {
110			break;
111		}
112		return IIO_VAL_INT_PLUS_MICRO;
113	case IIO_CHAN_INFO_SAMP_FREQ:
114		cr = (data->config & TMP006_CONFIG_CR_MASK)
115			>> TMP006_CONFIG_CR_SHIFT;
116		*val = tmp006_freqs[cr][0];
117		*val2 = tmp006_freqs[cr][1];
118		return IIO_VAL_INT_PLUS_MICRO;
119	default:
120		break;
121	}
122
123	return -EINVAL;
124}
125
126static int tmp006_write_raw(struct iio_dev *indio_dev,
127			    struct iio_chan_spec const *chan,
128			    int val,
129			    int val2,
130			    long mask)
131{
132	struct tmp006_data *data = iio_priv(indio_dev);
133	int i;
134
135	if (mask != IIO_CHAN_INFO_SAMP_FREQ)
136		return -EINVAL;
137
138	for (i = 0; i < ARRAY_SIZE(tmp006_freqs); i++)
139		if ((val == tmp006_freqs[i][0]) &&
140		    (val2 == tmp006_freqs[i][1])) {
141			data->config &= ~TMP006_CONFIG_CR_MASK;
142			data->config |= i << TMP006_CONFIG_CR_SHIFT;
143
144			return i2c_smbus_write_word_swapped(data->client,
145							    TMP006_CONFIG,
146							    data->config);
147
148		}
149	return -EINVAL;
150}
151
152static IIO_CONST_ATTR(sampling_frequency_available, "4 2 1 0.5 0.25");
153
154static struct attribute *tmp006_attributes[] = {
155	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
156	NULL
157};
158
159static const struct attribute_group tmp006_attribute_group = {
160	.attrs = tmp006_attributes,
161};
162
163static const struct iio_chan_spec tmp006_channels[] = {
164	{
165		.type = IIO_VOLTAGE,
166		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
167			BIT(IIO_CHAN_INFO_SCALE),
168		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
169	},
170	{
171		.type = IIO_TEMP,
172		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
173			BIT(IIO_CHAN_INFO_SCALE),
174		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
175	}
176};
177
178static const struct iio_info tmp006_info = {
179	.read_raw = tmp006_read_raw,
180	.write_raw = tmp006_write_raw,
181	.attrs = &tmp006_attribute_group,
182	.driver_module = THIS_MODULE,
183};
184
185static bool tmp006_check_identification(struct i2c_client *client)
186{
187	int mid, did;
188
189	mid = i2c_smbus_read_word_swapped(client, TMP006_MANUFACTURER_ID);
190	if (mid < 0)
191		return false;
192
193	did = i2c_smbus_read_word_swapped(client, TMP006_DEVICE_ID);
194	if (did < 0)
195		return false;
196
197	return mid == TMP006_MANUFACTURER_MAGIC && did == TMP006_DEVICE_MAGIC;
198}
199
200static int tmp006_probe(struct i2c_client *client,
201			 const struct i2c_device_id *id)
202{
203	struct iio_dev *indio_dev;
204	struct tmp006_data *data;
205	int ret;
206
207	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
208		return -EOPNOTSUPP;
209
210	if (!tmp006_check_identification(client)) {
211		dev_err(&client->dev, "no TMP006 sensor\n");
212		return -ENODEV;
213	}
214
215	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
216	if (!indio_dev)
217		return -ENOMEM;
218
219	data = iio_priv(indio_dev);
220	i2c_set_clientdata(client, indio_dev);
221	data->client = client;
222
223	indio_dev->dev.parent = &client->dev;
224	indio_dev->name = dev_name(&client->dev);
225	indio_dev->modes = INDIO_DIRECT_MODE;
226	indio_dev->info = &tmp006_info;
227
228	indio_dev->channels = tmp006_channels;
229	indio_dev->num_channels = ARRAY_SIZE(tmp006_channels);
230
231	ret = i2c_smbus_read_word_swapped(data->client, TMP006_CONFIG);
232	if (ret < 0)
233		return ret;
234	data->config = ret;
235
236	return iio_device_register(indio_dev);
237}
238
239static int tmp006_powerdown(struct tmp006_data *data)
240{
241	return i2c_smbus_write_word_swapped(data->client, TMP006_CONFIG,
242		data->config & ~TMP006_CONFIG_MOD_MASK);
243}
244
245static int tmp006_remove(struct i2c_client *client)
246{
247	struct iio_dev *indio_dev = i2c_get_clientdata(client);
248
249	iio_device_unregister(indio_dev);
250	tmp006_powerdown(iio_priv(indio_dev));
251
252	return 0;
253}
254
255#ifdef CONFIG_PM_SLEEP
256static int tmp006_suspend(struct device *dev)
257{
258	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
259	return tmp006_powerdown(iio_priv(indio_dev));
260}
261
262static int tmp006_resume(struct device *dev)
263{
264	struct tmp006_data *data = iio_priv(i2c_get_clientdata(
265		to_i2c_client(dev)));
266	return i2c_smbus_write_word_swapped(data->client, TMP006_CONFIG,
267		data->config | TMP006_CONFIG_MOD_MASK);
268}
269#endif
270
271static SIMPLE_DEV_PM_OPS(tmp006_pm_ops, tmp006_suspend, tmp006_resume);
272
273static const struct i2c_device_id tmp006_id[] = {
274	{ "tmp006", 0 },
275	{ }
276};
277MODULE_DEVICE_TABLE(i2c, tmp006_id);
278
279static struct i2c_driver tmp006_driver = {
280	.driver = {
281		.name	= "tmp006",
282		.pm	= &tmp006_pm_ops,
283	},
284	.probe = tmp006_probe,
285	.remove = tmp006_remove,
286	.id_table = tmp006_id,
287};
288module_i2c_driver(tmp006_driver);
289
290MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
291MODULE_DESCRIPTION("TI TMP006 IR thermopile sensor driver");
292MODULE_LICENSE("GPL");