treewide: remove redundant IS_ERR() before error code check
[linux/fpc-iii.git] / drivers / iio / temperature / mlx90614.c
blobb7c56ddf884fdd8043625f2b11545d93063495f4
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * mlx90614.c - Support for Melexis MLX90614 contactless IR temperature sensor
5 * Copyright (c) 2014 Peter Meerwald <pmeerw@pmeerw.net>
6 * Copyright (c) 2015 Essensium NV
7 * Copyright (c) 2015 Melexis
9 * Driver for the Melexis MLX90614 I2C 16-bit IR thermopile sensor
11 * (7-bit I2C slave address 0x5a, 100KHz bus speed only!)
13 * To wake up from sleep mode, the SDA line must be held low while SCL is high
14 * for at least 33ms. This is achieved with an extra GPIO that can be connected
15 * directly to the SDA line. In normal operation, the GPIO is set as input and
16 * will not interfere in I2C communication. While the GPIO is driven low, the
17 * i2c adapter is locked since it cannot be used by other clients. The SCL line
18 * always has a pull-up so we do not need an extra GPIO to drive it high. If
19 * the "wakeup" GPIO is not given, power management will be disabled.
22 #include <linux/err.h>
23 #include <linux/i2c.h>
24 #include <linux/module.h>
25 #include <linux/delay.h>
26 #include <linux/jiffies.h>
27 #include <linux/gpio/consumer.h>
28 #include <linux/pm_runtime.h>
30 #include <linux/iio/iio.h>
31 #include <linux/iio/sysfs.h>
33 #define MLX90614_OP_RAM 0x00
34 #define MLX90614_OP_EEPROM 0x20
35 #define MLX90614_OP_SLEEP 0xff
37 /* RAM offsets with 16-bit data, MSB first */
38 #define MLX90614_RAW1 (MLX90614_OP_RAM | 0x04) /* raw data IR channel 1 */
39 #define MLX90614_RAW2 (MLX90614_OP_RAM | 0x05) /* raw data IR channel 2 */
40 #define MLX90614_TA (MLX90614_OP_RAM | 0x06) /* ambient temperature */
41 #define MLX90614_TOBJ1 (MLX90614_OP_RAM | 0x07) /* object 1 temperature */
42 #define MLX90614_TOBJ2 (MLX90614_OP_RAM | 0x08) /* object 2 temperature */
44 /* EEPROM offsets with 16-bit data, MSB first */
45 #define MLX90614_EMISSIVITY (MLX90614_OP_EEPROM | 0x04) /* emissivity correction coefficient */
46 #define MLX90614_CONFIG (MLX90614_OP_EEPROM | 0x05) /* configuration register */
48 /* Control bits in configuration register */
49 #define MLX90614_CONFIG_IIR_SHIFT 0 /* IIR coefficient */
50 #define MLX90614_CONFIG_IIR_MASK (0x7 << MLX90614_CONFIG_IIR_SHIFT)
51 #define MLX90614_CONFIG_DUAL_SHIFT 6 /* single (0) or dual (1) IR sensor */
52 #define MLX90614_CONFIG_DUAL_MASK (1 << MLX90614_CONFIG_DUAL_SHIFT)
53 #define MLX90614_CONFIG_FIR_SHIFT 8 /* FIR coefficient */
54 #define MLX90614_CONFIG_FIR_MASK (0x7 << MLX90614_CONFIG_FIR_SHIFT)
55 #define MLX90614_CONFIG_GAIN_SHIFT 11 /* gain */
56 #define MLX90614_CONFIG_GAIN_MASK (0x7 << MLX90614_CONFIG_GAIN_SHIFT)
58 /* Timings (in ms) */
59 #define MLX90614_TIMING_EEPROM 20 /* time for EEPROM write/erase to complete */
60 #define MLX90614_TIMING_WAKEUP 34 /* time to hold SDA low for wake-up */
61 #define MLX90614_TIMING_STARTUP 250 /* time before first data after wake-up */
63 #define MLX90614_AUTOSLEEP_DELAY 5000 /* default autosleep delay */
65 /* Magic constants */
66 #define MLX90614_CONST_OFFSET_DEC -13657 /* decimal part of the Kelvin offset */
67 #define MLX90614_CONST_OFFSET_REM 500000 /* remainder of offset (273.15*50) */
68 #define MLX90614_CONST_SCALE 20 /* Scale in milliKelvin (0.02 * 1000) */
69 #define MLX90614_CONST_RAW_EMISSIVITY_MAX 65535 /* max value for emissivity */
70 #define MLX90614_CONST_EMISSIVITY_RESOLUTION 15259 /* 1/65535 ~ 0.000015259 */
71 #define MLX90614_CONST_FIR 0x7 /* Fixed value for FIR part of low pass filter */
73 struct mlx90614_data {
74 struct i2c_client *client;
75 struct mutex lock; /* for EEPROM access only */
76 struct gpio_desc *wakeup_gpio; /* NULL to disable sleep/wake-up */
77 unsigned long ready_timestamp; /* in jiffies */
80 /* Bandwidth values for IIR filtering */
81 static const int mlx90614_iir_values[] = {77, 31, 20, 15, 723, 153, 110, 86};
82 static IIO_CONST_ATTR(in_temp_object_filter_low_pass_3db_frequency_available,
83 "0.15 0.20 0.31 0.77 0.86 1.10 1.53 7.23");
85 static struct attribute *mlx90614_attributes[] = {
86 &iio_const_attr_in_temp_object_filter_low_pass_3db_frequency_available.dev_attr.attr,
87 NULL,
90 static const struct attribute_group mlx90614_attr_group = {
91 .attrs = mlx90614_attributes,
95 * Erase an address and write word.
96 * The mutex must be locked before calling.
98 static s32 mlx90614_write_word(const struct i2c_client *client, u8 command,
99 u16 value)
102 * Note: The mlx90614 requires a PEC on writing but does not send us a
103 * valid PEC on reading. Hence, we cannot set I2C_CLIENT_PEC in
104 * i2c_client.flags. As a workaround, we use i2c_smbus_xfer here.
106 union i2c_smbus_data data;
107 s32 ret;
109 dev_dbg(&client->dev, "Writing 0x%x to address 0x%x", value, command);
111 data.word = 0x0000; /* erase command */
112 ret = i2c_smbus_xfer(client->adapter, client->addr,
113 client->flags | I2C_CLIENT_PEC,
114 I2C_SMBUS_WRITE, command,
115 I2C_SMBUS_WORD_DATA, &data);
116 if (ret < 0)
117 return ret;
119 msleep(MLX90614_TIMING_EEPROM);
121 data.word = value; /* actual write */
122 ret = i2c_smbus_xfer(client->adapter, client->addr,
123 client->flags | I2C_CLIENT_PEC,
124 I2C_SMBUS_WRITE, command,
125 I2C_SMBUS_WORD_DATA, &data);
127 msleep(MLX90614_TIMING_EEPROM);
129 return ret;
133 * Find the IIR value inside mlx90614_iir_values array and return its position
134 * which is equivalent to the bit value in sensor register
136 static inline s32 mlx90614_iir_search(const struct i2c_client *client,
137 int value)
139 int i;
140 s32 ret;
142 for (i = 0; i < ARRAY_SIZE(mlx90614_iir_values); ++i) {
143 if (value == mlx90614_iir_values[i])
144 break;
147 if (i == ARRAY_SIZE(mlx90614_iir_values))
148 return -EINVAL;
151 * CONFIG register values must not be changed so
152 * we must read them before we actually write
153 * changes
155 ret = i2c_smbus_read_word_data(client, MLX90614_CONFIG);
156 if (ret < 0)
157 return ret;
159 ret &= ~MLX90614_CONFIG_FIR_MASK;
160 ret |= MLX90614_CONST_FIR << MLX90614_CONFIG_FIR_SHIFT;
161 ret &= ~MLX90614_CONFIG_IIR_MASK;
162 ret |= i << MLX90614_CONFIG_IIR_SHIFT;
164 /* Write changed values */
165 ret = mlx90614_write_word(client, MLX90614_CONFIG, ret);
166 return ret;
169 #ifdef CONFIG_PM
171 * If @startup is true, make sure MLX90614_TIMING_STARTUP ms have elapsed since
172 * the last wake-up. This is normally only needed to get a valid temperature
173 * reading. EEPROM access does not need such delay.
174 * Return 0 on success, <0 on error.
176 static int mlx90614_power_get(struct mlx90614_data *data, bool startup)
178 unsigned long now;
180 if (!data->wakeup_gpio)
181 return 0;
183 pm_runtime_get_sync(&data->client->dev);
185 if (startup) {
186 now = jiffies;
187 if (time_before(now, data->ready_timestamp) &&
188 msleep_interruptible(jiffies_to_msecs(
189 data->ready_timestamp - now)) != 0) {
190 pm_runtime_put_autosuspend(&data->client->dev);
191 return -EINTR;
195 return 0;
198 static void mlx90614_power_put(struct mlx90614_data *data)
200 if (!data->wakeup_gpio)
201 return;
203 pm_runtime_mark_last_busy(&data->client->dev);
204 pm_runtime_put_autosuspend(&data->client->dev);
206 #else
207 static inline int mlx90614_power_get(struct mlx90614_data *data, bool startup)
209 return 0;
212 static inline void mlx90614_power_put(struct mlx90614_data *data)
215 #endif
217 static int mlx90614_read_raw(struct iio_dev *indio_dev,
218 struct iio_chan_spec const *channel, int *val,
219 int *val2, long mask)
221 struct mlx90614_data *data = iio_priv(indio_dev);
222 u8 cmd;
223 s32 ret;
225 switch (mask) {
226 case IIO_CHAN_INFO_RAW: /* 0.02K / LSB */
227 switch (channel->channel2) {
228 case IIO_MOD_TEMP_AMBIENT:
229 cmd = MLX90614_TA;
230 break;
231 case IIO_MOD_TEMP_OBJECT:
232 switch (channel->channel) {
233 case 0:
234 cmd = MLX90614_TOBJ1;
235 break;
236 case 1:
237 cmd = MLX90614_TOBJ2;
238 break;
239 default:
240 return -EINVAL;
242 break;
243 default:
244 return -EINVAL;
247 ret = mlx90614_power_get(data, true);
248 if (ret < 0)
249 return ret;
250 ret = i2c_smbus_read_word_data(data->client, cmd);
251 mlx90614_power_put(data);
253 if (ret < 0)
254 return ret;
256 /* MSB is an error flag */
257 if (ret & 0x8000)
258 return -EIO;
260 *val = ret;
261 return IIO_VAL_INT;
262 case IIO_CHAN_INFO_OFFSET:
263 *val = MLX90614_CONST_OFFSET_DEC;
264 *val2 = MLX90614_CONST_OFFSET_REM;
265 return IIO_VAL_INT_PLUS_MICRO;
266 case IIO_CHAN_INFO_SCALE:
267 *val = MLX90614_CONST_SCALE;
268 return IIO_VAL_INT;
269 case IIO_CHAN_INFO_CALIBEMISSIVITY: /* 1/65535 / LSB */
270 mlx90614_power_get(data, false);
271 mutex_lock(&data->lock);
272 ret = i2c_smbus_read_word_data(data->client,
273 MLX90614_EMISSIVITY);
274 mutex_unlock(&data->lock);
275 mlx90614_power_put(data);
277 if (ret < 0)
278 return ret;
280 if (ret == MLX90614_CONST_RAW_EMISSIVITY_MAX) {
281 *val = 1;
282 *val2 = 0;
283 } else {
284 *val = 0;
285 *val2 = ret * MLX90614_CONST_EMISSIVITY_RESOLUTION;
287 return IIO_VAL_INT_PLUS_NANO;
288 case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: /* IIR setting with
289 FIR = 1024 */
290 mlx90614_power_get(data, false);
291 mutex_lock(&data->lock);
292 ret = i2c_smbus_read_word_data(data->client, MLX90614_CONFIG);
293 mutex_unlock(&data->lock);
294 mlx90614_power_put(data);
296 if (ret < 0)
297 return ret;
299 *val = mlx90614_iir_values[ret & MLX90614_CONFIG_IIR_MASK] / 100;
300 *val2 = (mlx90614_iir_values[ret & MLX90614_CONFIG_IIR_MASK] % 100) *
301 10000;
302 return IIO_VAL_INT_PLUS_MICRO;
303 default:
304 return -EINVAL;
308 static int mlx90614_write_raw(struct iio_dev *indio_dev,
309 struct iio_chan_spec const *channel, int val,
310 int val2, long mask)
312 struct mlx90614_data *data = iio_priv(indio_dev);
313 s32 ret;
315 switch (mask) {
316 case IIO_CHAN_INFO_CALIBEMISSIVITY: /* 1/65535 / LSB */
317 if (val < 0 || val2 < 0 || val > 1 || (val == 1 && val2 != 0))
318 return -EINVAL;
319 val = val * MLX90614_CONST_RAW_EMISSIVITY_MAX +
320 val2 / MLX90614_CONST_EMISSIVITY_RESOLUTION;
322 mlx90614_power_get(data, false);
323 mutex_lock(&data->lock);
324 ret = mlx90614_write_word(data->client, MLX90614_EMISSIVITY,
325 val);
326 mutex_unlock(&data->lock);
327 mlx90614_power_put(data);
329 return ret;
330 case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: /* IIR Filter setting */
331 if (val < 0 || val2 < 0)
332 return -EINVAL;
334 mlx90614_power_get(data, false);
335 mutex_lock(&data->lock);
336 ret = mlx90614_iir_search(data->client,
337 val * 100 + val2 / 10000);
338 mutex_unlock(&data->lock);
339 mlx90614_power_put(data);
341 return ret;
342 default:
343 return -EINVAL;
347 static int mlx90614_write_raw_get_fmt(struct iio_dev *indio_dev,
348 struct iio_chan_spec const *channel,
349 long mask)
351 switch (mask) {
352 case IIO_CHAN_INFO_CALIBEMISSIVITY:
353 return IIO_VAL_INT_PLUS_NANO;
354 case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
355 return IIO_VAL_INT_PLUS_MICRO;
356 default:
357 return -EINVAL;
361 static const struct iio_chan_spec mlx90614_channels[] = {
363 .type = IIO_TEMP,
364 .modified = 1,
365 .channel2 = IIO_MOD_TEMP_AMBIENT,
366 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
367 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
368 BIT(IIO_CHAN_INFO_SCALE),
371 .type = IIO_TEMP,
372 .modified = 1,
373 .channel2 = IIO_MOD_TEMP_OBJECT,
374 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
375 BIT(IIO_CHAN_INFO_CALIBEMISSIVITY) |
376 BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),
377 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
378 BIT(IIO_CHAN_INFO_SCALE),
381 .type = IIO_TEMP,
382 .indexed = 1,
383 .modified = 1,
384 .channel = 1,
385 .channel2 = IIO_MOD_TEMP_OBJECT,
386 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
387 BIT(IIO_CHAN_INFO_CALIBEMISSIVITY) |
388 BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),
389 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
390 BIT(IIO_CHAN_INFO_SCALE),
394 static const struct iio_info mlx90614_info = {
395 .read_raw = mlx90614_read_raw,
396 .write_raw = mlx90614_write_raw,
397 .write_raw_get_fmt = mlx90614_write_raw_get_fmt,
398 .attrs = &mlx90614_attr_group,
401 #ifdef CONFIG_PM
402 static int mlx90614_sleep(struct mlx90614_data *data)
404 s32 ret;
406 if (!data->wakeup_gpio) {
407 dev_dbg(&data->client->dev, "Sleep disabled");
408 return -ENOSYS;
411 dev_dbg(&data->client->dev, "Requesting sleep");
413 mutex_lock(&data->lock);
414 ret = i2c_smbus_xfer(data->client->adapter, data->client->addr,
415 data->client->flags | I2C_CLIENT_PEC,
416 I2C_SMBUS_WRITE, MLX90614_OP_SLEEP,
417 I2C_SMBUS_BYTE, NULL);
418 mutex_unlock(&data->lock);
420 return ret;
423 static int mlx90614_wakeup(struct mlx90614_data *data)
425 if (!data->wakeup_gpio) {
426 dev_dbg(&data->client->dev, "Wake-up disabled");
427 return -ENOSYS;
430 dev_dbg(&data->client->dev, "Requesting wake-up");
432 i2c_lock_bus(data->client->adapter, I2C_LOCK_ROOT_ADAPTER);
433 gpiod_direction_output(data->wakeup_gpio, 0);
434 msleep(MLX90614_TIMING_WAKEUP);
435 gpiod_direction_input(data->wakeup_gpio);
436 i2c_unlock_bus(data->client->adapter, I2C_LOCK_ROOT_ADAPTER);
438 data->ready_timestamp = jiffies +
439 msecs_to_jiffies(MLX90614_TIMING_STARTUP);
442 * Quirk: the i2c controller may get confused right after the
443 * wake-up signal has been sent. As a workaround, do a dummy read.
444 * If the read fails, the controller will probably be reset so that
445 * further reads will work.
447 i2c_smbus_read_word_data(data->client, MLX90614_CONFIG);
449 return 0;
452 /* Return wake-up GPIO or NULL if sleep functionality should be disabled. */
453 static struct gpio_desc *mlx90614_probe_wakeup(struct i2c_client *client)
455 struct gpio_desc *gpio;
457 if (!i2c_check_functionality(client->adapter,
458 I2C_FUNC_SMBUS_WRITE_BYTE)) {
459 dev_info(&client->dev,
460 "i2c adapter does not support SMBUS_WRITE_BYTE, sleep disabled");
461 return NULL;
464 gpio = devm_gpiod_get_optional(&client->dev, "wakeup", GPIOD_IN);
466 if (IS_ERR(gpio)) {
467 dev_warn(&client->dev,
468 "gpio acquisition failed with error %ld, sleep disabled",
469 PTR_ERR(gpio));
470 return NULL;
471 } else if (!gpio) {
472 dev_info(&client->dev,
473 "wakeup-gpio not found, sleep disabled");
476 return gpio;
478 #else
479 static inline int mlx90614_sleep(struct mlx90614_data *data)
481 return -ENOSYS;
483 static inline int mlx90614_wakeup(struct mlx90614_data *data)
485 return -ENOSYS;
487 static inline struct gpio_desc *mlx90614_probe_wakeup(struct i2c_client *client)
489 return NULL;
491 #endif
493 /* Return 0 for single sensor, 1 for dual sensor, <0 on error. */
494 static int mlx90614_probe_num_ir_sensors(struct i2c_client *client)
496 s32 ret;
498 ret = i2c_smbus_read_word_data(client, MLX90614_CONFIG);
500 if (ret < 0)
501 return ret;
503 return (ret & MLX90614_CONFIG_DUAL_MASK) ? 1 : 0;
506 static int mlx90614_probe(struct i2c_client *client,
507 const struct i2c_device_id *id)
509 struct iio_dev *indio_dev;
510 struct mlx90614_data *data;
511 int ret;
513 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
514 return -EOPNOTSUPP;
516 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
517 if (!indio_dev)
518 return -ENOMEM;
520 data = iio_priv(indio_dev);
521 i2c_set_clientdata(client, indio_dev);
522 data->client = client;
523 mutex_init(&data->lock);
524 data->wakeup_gpio = mlx90614_probe_wakeup(client);
526 mlx90614_wakeup(data);
528 indio_dev->dev.parent = &client->dev;
529 indio_dev->name = id->name;
530 indio_dev->modes = INDIO_DIRECT_MODE;
531 indio_dev->info = &mlx90614_info;
533 ret = mlx90614_probe_num_ir_sensors(client);
534 switch (ret) {
535 case 0:
536 dev_dbg(&client->dev, "Found single sensor");
537 indio_dev->channels = mlx90614_channels;
538 indio_dev->num_channels = 2;
539 break;
540 case 1:
541 dev_dbg(&client->dev, "Found dual sensor");
542 indio_dev->channels = mlx90614_channels;
543 indio_dev->num_channels = 3;
544 break;
545 default:
546 return ret;
549 if (data->wakeup_gpio) {
550 pm_runtime_set_autosuspend_delay(&client->dev,
551 MLX90614_AUTOSLEEP_DELAY);
552 pm_runtime_use_autosuspend(&client->dev);
553 pm_runtime_set_active(&client->dev);
554 pm_runtime_enable(&client->dev);
557 return iio_device_register(indio_dev);
560 static int mlx90614_remove(struct i2c_client *client)
562 struct iio_dev *indio_dev = i2c_get_clientdata(client);
563 struct mlx90614_data *data = iio_priv(indio_dev);
565 iio_device_unregister(indio_dev);
567 if (data->wakeup_gpio) {
568 pm_runtime_disable(&client->dev);
569 if (!pm_runtime_status_suspended(&client->dev))
570 mlx90614_sleep(data);
571 pm_runtime_set_suspended(&client->dev);
574 return 0;
577 static const struct i2c_device_id mlx90614_id[] = {
578 { "mlx90614", 0 },
581 MODULE_DEVICE_TABLE(i2c, mlx90614_id);
583 static const struct of_device_id mlx90614_of_match[] = {
584 { .compatible = "melexis,mlx90614" },
587 MODULE_DEVICE_TABLE(of, mlx90614_of_match);
589 #ifdef CONFIG_PM_SLEEP
590 static int mlx90614_pm_suspend(struct device *dev)
592 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
593 struct mlx90614_data *data = iio_priv(indio_dev);
595 if (data->wakeup_gpio && pm_runtime_active(dev))
596 return mlx90614_sleep(data);
598 return 0;
601 static int mlx90614_pm_resume(struct device *dev)
603 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
604 struct mlx90614_data *data = iio_priv(indio_dev);
605 int err;
607 if (data->wakeup_gpio) {
608 err = mlx90614_wakeup(data);
609 if (err < 0)
610 return err;
612 pm_runtime_disable(dev);
613 pm_runtime_set_active(dev);
614 pm_runtime_enable(dev);
617 return 0;
619 #endif
621 #ifdef CONFIG_PM
622 static int mlx90614_pm_runtime_suspend(struct device *dev)
624 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
625 struct mlx90614_data *data = iio_priv(indio_dev);
627 return mlx90614_sleep(data);
630 static int mlx90614_pm_runtime_resume(struct device *dev)
632 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
633 struct mlx90614_data *data = iio_priv(indio_dev);
635 return mlx90614_wakeup(data);
637 #endif
639 static const struct dev_pm_ops mlx90614_pm_ops = {
640 SET_SYSTEM_SLEEP_PM_OPS(mlx90614_pm_suspend, mlx90614_pm_resume)
641 SET_RUNTIME_PM_OPS(mlx90614_pm_runtime_suspend,
642 mlx90614_pm_runtime_resume, NULL)
645 static struct i2c_driver mlx90614_driver = {
646 .driver = {
647 .name = "mlx90614",
648 .of_match_table = mlx90614_of_match,
649 .pm = &mlx90614_pm_ops,
651 .probe = mlx90614_probe,
652 .remove = mlx90614_remove,
653 .id_table = mlx90614_id,
655 module_i2c_driver(mlx90614_driver);
657 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
658 MODULE_AUTHOR("Vianney le Clément de Saint-Marcq <vianney.leclement@essensium.com>");
659 MODULE_AUTHOR("Crt Mori <cmo@melexis.com>");
660 MODULE_DESCRIPTION("Melexis MLX90614 contactless IR temperature sensor driver");
661 MODULE_LICENSE("GPL");