r8152: fix tx packets accounting
[linux/fpc-iii.git] / drivers / iio / temperature / mlx90614.c
blob4b645fc672aad8b85d02ebaede8e244bb17c8d32
1 /*
2 * mlx90614.c - Support for Melexis MLX90614 contactless IR temperature sensor
4 * Copyright (c) 2014 Peter Meerwald <pmeerw@pmeerw.net>
5 * Copyright (c) 2015 Essensium NV
6 * Copyright (c) 2015 Melexis
8 * This file is subject to the terms and conditions of version 2 of
9 * the GNU General Public License. See the file COPYING in the main
10 * directory of this archive for more details.
12 * Driver for the Melexis MLX90614 I2C 16-bit IR thermopile sensor
14 * (7-bit I2C slave address 0x5a, 100KHz bus speed only!)
16 * To wake up from sleep mode, the SDA line must be held low while SCL is high
17 * for at least 33ms. This is achieved with an extra GPIO that can be connected
18 * directly to the SDA line. In normal operation, the GPIO is set as input and
19 * will not interfere in I2C communication. While the GPIO is driven low, the
20 * i2c adapter is locked since it cannot be used by other clients. The SCL line
21 * always has a pull-up so we do not need an extra GPIO to drive it high. If
22 * the "wakeup" GPIO is not given, power management will be disabled.
26 #include <linux/err.h>
27 #include <linux/i2c.h>
28 #include <linux/module.h>
29 #include <linux/delay.h>
30 #include <linux/jiffies.h>
31 #include <linux/gpio/consumer.h>
32 #include <linux/pm_runtime.h>
34 #include <linux/iio/iio.h>
35 #include <linux/iio/sysfs.h>
37 #define MLX90614_OP_RAM 0x00
38 #define MLX90614_OP_EEPROM 0x20
39 #define MLX90614_OP_SLEEP 0xff
41 /* RAM offsets with 16-bit data, MSB first */
42 #define MLX90614_RAW1 (MLX90614_OP_RAM | 0x04) /* raw data IR channel 1 */
43 #define MLX90614_RAW2 (MLX90614_OP_RAM | 0x05) /* raw data IR channel 2 */
44 #define MLX90614_TA (MLX90614_OP_RAM | 0x06) /* ambient temperature */
45 #define MLX90614_TOBJ1 (MLX90614_OP_RAM | 0x07) /* object 1 temperature */
46 #define MLX90614_TOBJ2 (MLX90614_OP_RAM | 0x08) /* object 2 temperature */
48 /* EEPROM offsets with 16-bit data, MSB first */
49 #define MLX90614_EMISSIVITY (MLX90614_OP_EEPROM | 0x04) /* emissivity correction coefficient */
50 #define MLX90614_CONFIG (MLX90614_OP_EEPROM | 0x05) /* configuration register */
52 /* Control bits in configuration register */
53 #define MLX90614_CONFIG_IIR_SHIFT 0 /* IIR coefficient */
54 #define MLX90614_CONFIG_IIR_MASK (0x7 << MLX90614_CONFIG_IIR_SHIFT)
55 #define MLX90614_CONFIG_DUAL_SHIFT 6 /* single (0) or dual (1) IR sensor */
56 #define MLX90614_CONFIG_DUAL_MASK (1 << MLX90614_CONFIG_DUAL_SHIFT)
57 #define MLX90614_CONFIG_FIR_SHIFT 8 /* FIR coefficient */
58 #define MLX90614_CONFIG_FIR_MASK (0x7 << MLX90614_CONFIG_FIR_SHIFT)
59 #define MLX90614_CONFIG_GAIN_SHIFT 11 /* gain */
60 #define MLX90614_CONFIG_GAIN_MASK (0x7 << MLX90614_CONFIG_GAIN_SHIFT)
62 /* Timings (in ms) */
63 #define MLX90614_TIMING_EEPROM 20 /* time for EEPROM write/erase to complete */
64 #define MLX90614_TIMING_WAKEUP 34 /* time to hold SDA low for wake-up */
65 #define MLX90614_TIMING_STARTUP 250 /* time before first data after wake-up */
67 #define MLX90614_AUTOSLEEP_DELAY 5000 /* default autosleep delay */
69 /* Magic constants */
70 #define MLX90614_CONST_OFFSET_DEC -13657 /* decimal part of the Kelvin offset */
71 #define MLX90614_CONST_OFFSET_REM 500000 /* remainder of offset (273.15*50) */
72 #define MLX90614_CONST_SCALE 20 /* Scale in milliKelvin (0.02 * 1000) */
73 #define MLX90614_CONST_RAW_EMISSIVITY_MAX 65535 /* max value for emissivity */
74 #define MLX90614_CONST_EMISSIVITY_RESOLUTION 15259 /* 1/65535 ~ 0.000015259 */
75 #define MLX90614_CONST_FIR 0x7 /* Fixed value for FIR part of low pass filter */
77 struct mlx90614_data {
78 struct i2c_client *client;
79 struct mutex lock; /* for EEPROM access only */
80 struct gpio_desc *wakeup_gpio; /* NULL to disable sleep/wake-up */
81 unsigned long ready_timestamp; /* in jiffies */
84 /* Bandwidth values for IIR filtering */
85 static const int mlx90614_iir_values[] = {77, 31, 20, 15, 723, 153, 110, 86};
86 static IIO_CONST_ATTR(in_temp_object_filter_low_pass_3db_frequency_available,
87 "0.15 0.20 0.31 0.77 0.86 1.10 1.53 7.23");
89 static struct attribute *mlx90614_attributes[] = {
90 &iio_const_attr_in_temp_object_filter_low_pass_3db_frequency_available.dev_attr.attr,
91 NULL,
94 static const struct attribute_group mlx90614_attr_group = {
95 .attrs = mlx90614_attributes,
99 * Erase an address and write word.
100 * The mutex must be locked before calling.
102 static s32 mlx90614_write_word(const struct i2c_client *client, u8 command,
103 u16 value)
106 * Note: The mlx90614 requires a PEC on writing but does not send us a
107 * valid PEC on reading. Hence, we cannot set I2C_CLIENT_PEC in
108 * i2c_client.flags. As a workaround, we use i2c_smbus_xfer here.
110 union i2c_smbus_data data;
111 s32 ret;
113 dev_dbg(&client->dev, "Writing 0x%x to address 0x%x", value, command);
115 data.word = 0x0000; /* erase command */
116 ret = i2c_smbus_xfer(client->adapter, client->addr,
117 client->flags | I2C_CLIENT_PEC,
118 I2C_SMBUS_WRITE, command,
119 I2C_SMBUS_WORD_DATA, &data);
120 if (ret < 0)
121 return ret;
123 msleep(MLX90614_TIMING_EEPROM);
125 data.word = value; /* actual write */
126 ret = i2c_smbus_xfer(client->adapter, client->addr,
127 client->flags | I2C_CLIENT_PEC,
128 I2C_SMBUS_WRITE, command,
129 I2C_SMBUS_WORD_DATA, &data);
131 msleep(MLX90614_TIMING_EEPROM);
133 return ret;
137 * Find the IIR value inside mlx90614_iir_values array and return its position
138 * which is equivalent to the bit value in sensor register
140 static inline s32 mlx90614_iir_search(const struct i2c_client *client,
141 int value)
143 int i;
144 s32 ret;
146 for (i = 0; i < ARRAY_SIZE(mlx90614_iir_values); ++i) {
147 if (value == mlx90614_iir_values[i])
148 break;
151 if (i == ARRAY_SIZE(mlx90614_iir_values))
152 return -EINVAL;
155 * CONFIG register values must not be changed so
156 * we must read them before we actually write
157 * changes
159 ret = i2c_smbus_read_word_data(client, MLX90614_CONFIG);
160 if (ret < 0)
161 return ret;
163 ret &= ~MLX90614_CONFIG_FIR_MASK;
164 ret |= MLX90614_CONST_FIR << MLX90614_CONFIG_FIR_SHIFT;
165 ret &= ~MLX90614_CONFIG_IIR_MASK;
166 ret |= i << MLX90614_CONFIG_IIR_SHIFT;
168 /* Write changed values */
169 ret = mlx90614_write_word(client, MLX90614_CONFIG, ret);
170 return ret;
173 #ifdef CONFIG_PM
175 * If @startup is true, make sure MLX90614_TIMING_STARTUP ms have elapsed since
176 * the last wake-up. This is normally only needed to get a valid temperature
177 * reading. EEPROM access does not need such delay.
178 * Return 0 on success, <0 on error.
180 static int mlx90614_power_get(struct mlx90614_data *data, bool startup)
182 unsigned long now;
184 if (!data->wakeup_gpio)
185 return 0;
187 pm_runtime_get_sync(&data->client->dev);
189 if (startup) {
190 now = jiffies;
191 if (time_before(now, data->ready_timestamp) &&
192 msleep_interruptible(jiffies_to_msecs(
193 data->ready_timestamp - now)) != 0) {
194 pm_runtime_put_autosuspend(&data->client->dev);
195 return -EINTR;
199 return 0;
202 static void mlx90614_power_put(struct mlx90614_data *data)
204 if (!data->wakeup_gpio)
205 return;
207 pm_runtime_mark_last_busy(&data->client->dev);
208 pm_runtime_put_autosuspend(&data->client->dev);
210 #else
211 static inline int mlx90614_power_get(struct mlx90614_data *data, bool startup)
213 return 0;
216 static inline void mlx90614_power_put(struct mlx90614_data *data)
219 #endif
221 static int mlx90614_read_raw(struct iio_dev *indio_dev,
222 struct iio_chan_spec const *channel, int *val,
223 int *val2, long mask)
225 struct mlx90614_data *data = iio_priv(indio_dev);
226 u8 cmd;
227 s32 ret;
229 switch (mask) {
230 case IIO_CHAN_INFO_RAW: /* 0.02K / LSB */
231 switch (channel->channel2) {
232 case IIO_MOD_TEMP_AMBIENT:
233 cmd = MLX90614_TA;
234 break;
235 case IIO_MOD_TEMP_OBJECT:
236 switch (channel->channel) {
237 case 0:
238 cmd = MLX90614_TOBJ1;
239 break;
240 case 1:
241 cmd = MLX90614_TOBJ2;
242 break;
243 default:
244 return -EINVAL;
246 break;
247 default:
248 return -EINVAL;
251 ret = mlx90614_power_get(data, true);
252 if (ret < 0)
253 return ret;
254 ret = i2c_smbus_read_word_data(data->client, cmd);
255 mlx90614_power_put(data);
257 if (ret < 0)
258 return ret;
260 /* MSB is an error flag */
261 if (ret & 0x8000)
262 return -EIO;
264 *val = ret;
265 return IIO_VAL_INT;
266 case IIO_CHAN_INFO_OFFSET:
267 *val = MLX90614_CONST_OFFSET_DEC;
268 *val2 = MLX90614_CONST_OFFSET_REM;
269 return IIO_VAL_INT_PLUS_MICRO;
270 case IIO_CHAN_INFO_SCALE:
271 *val = MLX90614_CONST_SCALE;
272 return IIO_VAL_INT;
273 case IIO_CHAN_INFO_CALIBEMISSIVITY: /* 1/65535 / LSB */
274 mlx90614_power_get(data, false);
275 mutex_lock(&data->lock);
276 ret = i2c_smbus_read_word_data(data->client,
277 MLX90614_EMISSIVITY);
278 mutex_unlock(&data->lock);
279 mlx90614_power_put(data);
281 if (ret < 0)
282 return ret;
284 if (ret == MLX90614_CONST_RAW_EMISSIVITY_MAX) {
285 *val = 1;
286 *val2 = 0;
287 } else {
288 *val = 0;
289 *val2 = ret * MLX90614_CONST_EMISSIVITY_RESOLUTION;
291 return IIO_VAL_INT_PLUS_NANO;
292 case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: /* IIR setting with
293 FIR = 1024 */
294 mlx90614_power_get(data, false);
295 mutex_lock(&data->lock);
296 ret = i2c_smbus_read_word_data(data->client, MLX90614_CONFIG);
297 mutex_unlock(&data->lock);
298 mlx90614_power_put(data);
300 if (ret < 0)
301 return ret;
303 *val = mlx90614_iir_values[ret & MLX90614_CONFIG_IIR_MASK] / 100;
304 *val2 = (mlx90614_iir_values[ret & MLX90614_CONFIG_IIR_MASK] % 100) *
305 10000;
306 return IIO_VAL_INT_PLUS_MICRO;
307 default:
308 return -EINVAL;
312 static int mlx90614_write_raw(struct iio_dev *indio_dev,
313 struct iio_chan_spec const *channel, int val,
314 int val2, long mask)
316 struct mlx90614_data *data = iio_priv(indio_dev);
317 s32 ret;
319 switch (mask) {
320 case IIO_CHAN_INFO_CALIBEMISSIVITY: /* 1/65535 / LSB */
321 if (val < 0 || val2 < 0 || val > 1 || (val == 1 && val2 != 0))
322 return -EINVAL;
323 val = val * MLX90614_CONST_RAW_EMISSIVITY_MAX +
324 val2 / MLX90614_CONST_EMISSIVITY_RESOLUTION;
326 mlx90614_power_get(data, false);
327 mutex_lock(&data->lock);
328 ret = mlx90614_write_word(data->client, MLX90614_EMISSIVITY,
329 val);
330 mutex_unlock(&data->lock);
331 mlx90614_power_put(data);
333 return ret;
334 case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: /* IIR Filter setting */
335 if (val < 0 || val2 < 0)
336 return -EINVAL;
338 mlx90614_power_get(data, false);
339 mutex_lock(&data->lock);
340 ret = mlx90614_iir_search(data->client,
341 val * 100 + val2 / 10000);
342 mutex_unlock(&data->lock);
343 mlx90614_power_put(data);
345 return ret;
346 default:
347 return -EINVAL;
351 static int mlx90614_write_raw_get_fmt(struct iio_dev *indio_dev,
352 struct iio_chan_spec const *channel,
353 long mask)
355 switch (mask) {
356 case IIO_CHAN_INFO_CALIBEMISSIVITY:
357 return IIO_VAL_INT_PLUS_NANO;
358 case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
359 return IIO_VAL_INT_PLUS_MICRO;
360 default:
361 return -EINVAL;
365 static const struct iio_chan_spec mlx90614_channels[] = {
367 .type = IIO_TEMP,
368 .modified = 1,
369 .channel2 = IIO_MOD_TEMP_AMBIENT,
370 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
371 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
372 BIT(IIO_CHAN_INFO_SCALE),
375 .type = IIO_TEMP,
376 .modified = 1,
377 .channel2 = IIO_MOD_TEMP_OBJECT,
378 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
379 BIT(IIO_CHAN_INFO_CALIBEMISSIVITY) |
380 BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),
381 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
382 BIT(IIO_CHAN_INFO_SCALE),
385 .type = IIO_TEMP,
386 .indexed = 1,
387 .modified = 1,
388 .channel = 1,
389 .channel2 = IIO_MOD_TEMP_OBJECT,
390 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
391 BIT(IIO_CHAN_INFO_CALIBEMISSIVITY) |
392 BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),
393 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
394 BIT(IIO_CHAN_INFO_SCALE),
398 static const struct iio_info mlx90614_info = {
399 .read_raw = mlx90614_read_raw,
400 .write_raw = mlx90614_write_raw,
401 .write_raw_get_fmt = mlx90614_write_raw_get_fmt,
402 .attrs = &mlx90614_attr_group,
403 .driver_module = THIS_MODULE,
406 #ifdef CONFIG_PM
407 static int mlx90614_sleep(struct mlx90614_data *data)
409 s32 ret;
411 if (!data->wakeup_gpio) {
412 dev_dbg(&data->client->dev, "Sleep disabled");
413 return -ENOSYS;
416 dev_dbg(&data->client->dev, "Requesting sleep");
418 mutex_lock(&data->lock);
419 ret = i2c_smbus_xfer(data->client->adapter, data->client->addr,
420 data->client->flags | I2C_CLIENT_PEC,
421 I2C_SMBUS_WRITE, MLX90614_OP_SLEEP,
422 I2C_SMBUS_BYTE, NULL);
423 mutex_unlock(&data->lock);
425 return ret;
428 static int mlx90614_wakeup(struct mlx90614_data *data)
430 if (!data->wakeup_gpio) {
431 dev_dbg(&data->client->dev, "Wake-up disabled");
432 return -ENOSYS;
435 dev_dbg(&data->client->dev, "Requesting wake-up");
437 i2c_lock_adapter(data->client->adapter);
438 gpiod_direction_output(data->wakeup_gpio, 0);
439 msleep(MLX90614_TIMING_WAKEUP);
440 gpiod_direction_input(data->wakeup_gpio);
441 i2c_unlock_adapter(data->client->adapter);
443 data->ready_timestamp = jiffies +
444 msecs_to_jiffies(MLX90614_TIMING_STARTUP);
447 * Quirk: the i2c controller may get confused right after the
448 * wake-up signal has been sent. As a workaround, do a dummy read.
449 * If the read fails, the controller will probably be reset so that
450 * further reads will work.
452 i2c_smbus_read_word_data(data->client, MLX90614_CONFIG);
454 return 0;
457 /* Return wake-up GPIO or NULL if sleep functionality should be disabled. */
458 static struct gpio_desc *mlx90614_probe_wakeup(struct i2c_client *client)
460 struct gpio_desc *gpio;
462 if (!i2c_check_functionality(client->adapter,
463 I2C_FUNC_SMBUS_WRITE_BYTE)) {
464 dev_info(&client->dev,
465 "i2c adapter does not support SMBUS_WRITE_BYTE, sleep disabled");
466 return NULL;
469 gpio = devm_gpiod_get_optional(&client->dev, "wakeup", GPIOD_IN);
471 if (IS_ERR(gpio)) {
472 dev_warn(&client->dev,
473 "gpio acquisition failed with error %ld, sleep disabled",
474 PTR_ERR(gpio));
475 return NULL;
476 } else if (!gpio) {
477 dev_info(&client->dev,
478 "wakeup-gpio not found, sleep disabled");
481 return gpio;
483 #else
484 static inline int mlx90614_sleep(struct mlx90614_data *data)
486 return -ENOSYS;
488 static inline int mlx90614_wakeup(struct mlx90614_data *data)
490 return -ENOSYS;
492 static inline struct gpio_desc *mlx90614_probe_wakeup(struct i2c_client *client)
494 return NULL;
496 #endif
498 /* Return 0 for single sensor, 1 for dual sensor, <0 on error. */
499 static int mlx90614_probe_num_ir_sensors(struct i2c_client *client)
501 s32 ret;
503 ret = i2c_smbus_read_word_data(client, MLX90614_CONFIG);
505 if (ret < 0)
506 return ret;
508 return (ret & MLX90614_CONFIG_DUAL_MASK) ? 1 : 0;
511 static int mlx90614_probe(struct i2c_client *client,
512 const struct i2c_device_id *id)
514 struct iio_dev *indio_dev;
515 struct mlx90614_data *data;
516 int ret;
518 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
519 return -EOPNOTSUPP;
521 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
522 if (!indio_dev)
523 return -ENOMEM;
525 data = iio_priv(indio_dev);
526 i2c_set_clientdata(client, indio_dev);
527 data->client = client;
528 mutex_init(&data->lock);
529 data->wakeup_gpio = mlx90614_probe_wakeup(client);
531 mlx90614_wakeup(data);
533 indio_dev->dev.parent = &client->dev;
534 indio_dev->name = id->name;
535 indio_dev->modes = INDIO_DIRECT_MODE;
536 indio_dev->info = &mlx90614_info;
538 ret = mlx90614_probe_num_ir_sensors(client);
539 switch (ret) {
540 case 0:
541 dev_dbg(&client->dev, "Found single sensor");
542 indio_dev->channels = mlx90614_channels;
543 indio_dev->num_channels = 2;
544 break;
545 case 1:
546 dev_dbg(&client->dev, "Found dual sensor");
547 indio_dev->channels = mlx90614_channels;
548 indio_dev->num_channels = 3;
549 break;
550 default:
551 return ret;
554 if (data->wakeup_gpio) {
555 pm_runtime_set_autosuspend_delay(&client->dev,
556 MLX90614_AUTOSLEEP_DELAY);
557 pm_runtime_use_autosuspend(&client->dev);
558 pm_runtime_set_active(&client->dev);
559 pm_runtime_enable(&client->dev);
562 return iio_device_register(indio_dev);
565 static int mlx90614_remove(struct i2c_client *client)
567 struct iio_dev *indio_dev = i2c_get_clientdata(client);
568 struct mlx90614_data *data = iio_priv(indio_dev);
570 iio_device_unregister(indio_dev);
572 if (data->wakeup_gpio) {
573 pm_runtime_disable(&client->dev);
574 if (!pm_runtime_status_suspended(&client->dev))
575 mlx90614_sleep(data);
576 pm_runtime_set_suspended(&client->dev);
579 return 0;
582 static const struct i2c_device_id mlx90614_id[] = {
583 { "mlx90614", 0 },
586 MODULE_DEVICE_TABLE(i2c, mlx90614_id);
588 #ifdef CONFIG_PM_SLEEP
589 static int mlx90614_pm_suspend(struct device *dev)
591 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
592 struct mlx90614_data *data = iio_priv(indio_dev);
594 if (data->wakeup_gpio && pm_runtime_active(dev))
595 return mlx90614_sleep(data);
597 return 0;
600 static int mlx90614_pm_resume(struct device *dev)
602 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
603 struct mlx90614_data *data = iio_priv(indio_dev);
604 int err;
606 if (data->wakeup_gpio) {
607 err = mlx90614_wakeup(data);
608 if (err < 0)
609 return err;
611 pm_runtime_disable(dev);
612 pm_runtime_set_active(dev);
613 pm_runtime_enable(dev);
616 return 0;
618 #endif
620 #ifdef CONFIG_PM
621 static int mlx90614_pm_runtime_suspend(struct device *dev)
623 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
624 struct mlx90614_data *data = iio_priv(indio_dev);
626 return mlx90614_sleep(data);
629 static int mlx90614_pm_runtime_resume(struct device *dev)
631 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
632 struct mlx90614_data *data = iio_priv(indio_dev);
634 return mlx90614_wakeup(data);
636 #endif
638 static const struct dev_pm_ops mlx90614_pm_ops = {
639 SET_SYSTEM_SLEEP_PM_OPS(mlx90614_pm_suspend, mlx90614_pm_resume)
640 SET_RUNTIME_PM_OPS(mlx90614_pm_runtime_suspend,
641 mlx90614_pm_runtime_resume, NULL)
644 static struct i2c_driver mlx90614_driver = {
645 .driver = {
646 .name = "mlx90614",
647 .pm = &mlx90614_pm_ops,
649 .probe = mlx90614_probe,
650 .remove = mlx90614_remove,
651 .id_table = mlx90614_id,
653 module_i2c_driver(mlx90614_driver);
655 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
656 MODULE_AUTHOR("Vianney le Clément de Saint-Marcq <vianney.leclement@essensium.com>");
657 MODULE_AUTHOR("Crt Mori <cmo@melexis.com>");
658 MODULE_DESCRIPTION("Melexis MLX90614 contactless IR temperature sensor driver");
659 MODULE_LICENSE("GPL");