xref: /openbmc/linux/drivers/iio/light/tsl2583.c (revision 726bd223)
1 /*
2  * Device driver for monitoring ambient light intensity (lux)
3  * within the TAOS tsl258x family of devices (tsl2580, tsl2581, tsl2583).
4  *
5  * Copyright (c) 2011, TAOS Corporation.
6  * Copyright (c) 2016 Brian Masney <masneyb@onstation.org>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful, but WITHOUT
14  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
15  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
16  * more details.
17  */
18 
19 #include <linux/kernel.h>
20 #include <linux/i2c.h>
21 #include <linux/errno.h>
22 #include <linux/delay.h>
23 #include <linux/string.h>
24 #include <linux/mutex.h>
25 #include <linux/unistd.h>
26 #include <linux/slab.h>
27 #include <linux/module.h>
28 #include <linux/iio/iio.h>
29 #include <linux/iio/sysfs.h>
30 
31 /* Device Registers and Masks */
32 #define TSL2583_CNTRL			0x00
33 #define TSL2583_ALS_TIME		0X01
34 #define TSL2583_INTERRUPT		0x02
35 #define TSL2583_GAIN			0x07
36 #define TSL2583_REVID			0x11
37 #define TSL2583_CHIPID			0x12
38 #define TSL2583_ALS_CHAN0LO		0x14
39 #define TSL2583_ALS_CHAN0HI		0x15
40 #define TSL2583_ALS_CHAN1LO		0x16
41 #define TSL2583_ALS_CHAN1HI		0x17
42 #define TSL2583_TMR_LO			0x18
43 #define TSL2583_TMR_HI			0x19
44 
45 /* tsl2583 cmd reg masks */
46 #define TSL2583_CMD_REG			0x80
47 #define TSL2583_CMD_SPL_FN		0x60
48 #define TSL2583_CMD_ALS_INT_CLR		0x01
49 
50 /* tsl2583 cntrl reg masks */
51 #define TSL2583_CNTL_ADC_ENBL		0x02
52 #define TSL2583_CNTL_PWR_OFF		0x00
53 #define TSL2583_CNTL_PWR_ON		0x01
54 
55 /* tsl2583 status reg masks */
56 #define TSL2583_STA_ADC_VALID		0x01
57 #define TSL2583_STA_ADC_INTR		0x10
58 
59 /* Lux calculation constants */
60 #define TSL2583_LUX_CALC_OVER_FLOW	65535
61 
62 #define TSL2583_INTERRUPT_DISABLED	0x00
63 
64 #define TSL2583_CHIP_ID			0x90
65 #define TSL2583_CHIP_ID_MASK		0xf0
66 
67 /* Per-device data */
68 struct tsl2583_als_info {
69 	u16 als_ch0;
70 	u16 als_ch1;
71 	u16 lux;
72 };
73 
74 struct tsl2583_lux {
75 	unsigned int ratio;
76 	unsigned int ch0;
77 	unsigned int ch1;
78 };
79 
80 static const struct tsl2583_lux tsl2583_default_lux[] = {
81 	{  9830,  8520, 15729 },
82 	{ 12452, 10807, 23344 },
83 	{ 14746,  6383, 11705 },
84 	{ 17695,  4063,  6554 },
85 	{     0,     0,     0 }  /* Termination segment */
86 };
87 
88 #define TSL2583_MAX_LUX_TABLE_ENTRIES 11
89 
90 struct tsl2583_settings {
91 	int als_time;
92 	int als_gain;
93 	int als_gain_trim;
94 	int als_cal_target;
95 
96 	/*
97 	 * This structure is intentionally large to accommodate updates via
98 	 * sysfs. Sized to 11 = max 10 segments + 1 termination segment.
99 	 * Assumption is that one and only one type of glass used.
100 	 */
101 	struct tsl2583_lux als_device_lux[TSL2583_MAX_LUX_TABLE_ENTRIES];
102 };
103 
104 struct tsl2583_chip {
105 	struct mutex als_mutex;
106 	struct i2c_client *client;
107 	struct tsl2583_als_info als_cur_info;
108 	struct tsl2583_settings als_settings;
109 	int als_time_scale;
110 	int als_saturation;
111 	bool suspended;
112 };
113 
114 struct gainadj {
115 	s16 ch0;
116 	s16 ch1;
117 	s16 mean;
118 };
119 
120 /* Index = (0 - 3) Used to validate the gain selection index */
121 static const struct gainadj gainadj[] = {
122 	{ 1, 1, 1 },
123 	{ 8, 8, 8 },
124 	{ 16, 16, 16 },
125 	{ 107, 115, 111 }
126 };
127 
128 /*
129  * Provides initial operational parameter defaults.
130  * These defaults may be changed through the device's sysfs files.
131  */
132 static void tsl2583_defaults(struct tsl2583_chip *chip)
133 {
134 	/*
135 	 * The integration time must be a multiple of 50ms and within the
136 	 * range [50, 600] ms.
137 	 */
138 	chip->als_settings.als_time = 100;
139 
140 	/*
141 	 * This is an index into the gainadj table. Assume clear glass as the
142 	 * default.
143 	 */
144 	chip->als_settings.als_gain = 0;
145 
146 	/* Default gain trim to account for aperture effects */
147 	chip->als_settings.als_gain_trim = 1000;
148 
149 	/* Known external ALS reading used for calibration */
150 	chip->als_settings.als_cal_target = 130;
151 
152 	/* Default lux table. */
153 	memcpy(chip->als_settings.als_device_lux, tsl2583_default_lux,
154 	       sizeof(tsl2583_default_lux));
155 }
156 
157 /*
158  * Reads and calculates current lux value.
159  * The raw ch0 and ch1 values of the ambient light sensed in the last
160  * integration cycle are read from the device.
161  * Time scale factor array values are adjusted based on the integration time.
162  * The raw values are multiplied by a scale factor, and device gain is obtained
163  * using gain index. Limit checks are done next, then the ratio of a multiple
164  * of ch1 value, to the ch0 value, is calculated. The array als_device_lux[]
165  * declared above is then scanned to find the first ratio value that is just
166  * above the ratio we just calculated. The ch0 and ch1 multiplier constants in
167  * the array are then used along with the time scale factor array values, to
168  * calculate the lux.
169  */
170 static int tsl2583_get_lux(struct iio_dev *indio_dev)
171 {
172 	u16 ch0, ch1; /* separated ch0/ch1 data from device */
173 	u32 lux; /* raw lux calculated from device data */
174 	u64 lux64;
175 	u32 ratio;
176 	u8 buf[5];
177 	struct tsl2583_lux *p;
178 	struct tsl2583_chip *chip = iio_priv(indio_dev);
179 	int i, ret;
180 
181 	ret = i2c_smbus_read_byte_data(chip->client, TSL2583_CMD_REG);
182 	if (ret < 0) {
183 		dev_err(&chip->client->dev, "%s: failed to read CMD_REG register\n",
184 			__func__);
185 		goto done;
186 	}
187 
188 	/* is data new & valid */
189 	if (!(ret & TSL2583_STA_ADC_INTR)) {
190 		dev_err(&chip->client->dev, "%s: data not valid; returning last value\n",
191 			__func__);
192 		ret = chip->als_cur_info.lux; /* return LAST VALUE */
193 		goto done;
194 	}
195 
196 	for (i = 0; i < 4; i++) {
197 		int reg = TSL2583_CMD_REG | (TSL2583_ALS_CHAN0LO + i);
198 
199 		ret = i2c_smbus_read_byte_data(chip->client, reg);
200 		if (ret < 0) {
201 			dev_err(&chip->client->dev, "%s: failed to read register %x\n",
202 				__func__, reg);
203 			goto done;
204 		}
205 		buf[i] = ret;
206 	}
207 
208 	/*
209 	 * Clear the pending interrupt status bit on the chip to allow the next
210 	 * integration cycle to start. This has to be done even though this
211 	 * driver currently does not support interrupts.
212 	 */
213 	ret = i2c_smbus_write_byte(chip->client,
214 				   (TSL2583_CMD_REG | TSL2583_CMD_SPL_FN |
215 				    TSL2583_CMD_ALS_INT_CLR));
216 	if (ret < 0) {
217 		dev_err(&chip->client->dev, "%s: failed to clear the interrupt bit\n",
218 			__func__);
219 		goto done; /* have no data, so return failure */
220 	}
221 
222 	/* extract ALS/lux data */
223 	ch0 = le16_to_cpup((const __le16 *)&buf[0]);
224 	ch1 = le16_to_cpup((const __le16 *)&buf[2]);
225 
226 	chip->als_cur_info.als_ch0 = ch0;
227 	chip->als_cur_info.als_ch1 = ch1;
228 
229 	if ((ch0 >= chip->als_saturation) || (ch1 >= chip->als_saturation))
230 		goto return_max;
231 
232 	if (!ch0) {
233 		/*
234 		 * The sensor appears to be in total darkness so set the
235 		 * calculated lux to 0 and return early to avoid a division by
236 		 * zero below when calculating the ratio.
237 		 */
238 		ret = 0;
239 		chip->als_cur_info.lux = 0;
240 		goto done;
241 	}
242 
243 	/* calculate ratio */
244 	ratio = (ch1 << 15) / ch0;
245 
246 	/* convert to unscaled lux using the pointer to the table */
247 	for (p = (struct tsl2583_lux *)chip->als_settings.als_device_lux;
248 	     p->ratio != 0 && p->ratio < ratio; p++)
249 		;
250 
251 	if (p->ratio == 0) {
252 		lux = 0;
253 	} else {
254 		u32 ch0lux, ch1lux;
255 
256 		ch0lux = ((ch0 * p->ch0) +
257 			  (gainadj[chip->als_settings.als_gain].ch0 >> 1))
258 			 / gainadj[chip->als_settings.als_gain].ch0;
259 		ch1lux = ((ch1 * p->ch1) +
260 			  (gainadj[chip->als_settings.als_gain].ch1 >> 1))
261 			 / gainadj[chip->als_settings.als_gain].ch1;
262 
263 		/* note: lux is 31 bit max at this point */
264 		if (ch1lux > ch0lux) {
265 			dev_dbg(&chip->client->dev, "%s: No Data - Returning 0\n",
266 				__func__);
267 			ret = 0;
268 			chip->als_cur_info.lux = 0;
269 			goto done;
270 		}
271 
272 		lux = ch0lux - ch1lux;
273 	}
274 
275 	/* adjust for active time scale */
276 	if (chip->als_time_scale == 0)
277 		lux = 0;
278 	else
279 		lux = (lux + (chip->als_time_scale >> 1)) /
280 			chip->als_time_scale;
281 
282 	/*
283 	 * Adjust for active gain scale.
284 	 * The tsl2583_default_lux tables above have a factor of 8192 built in,
285 	 * so we need to shift right.
286 	 * User-specified gain provides a multiplier.
287 	 * Apply user-specified gain before shifting right to retain precision.
288 	 * Use 64 bits to avoid overflow on multiplication.
289 	 * Then go back to 32 bits before division to avoid using div_u64().
290 	 */
291 	lux64 = lux;
292 	lux64 = lux64 * chip->als_settings.als_gain_trim;
293 	lux64 >>= 13;
294 	lux = lux64;
295 	lux = (lux + 500) / 1000;
296 
297 	if (lux > TSL2583_LUX_CALC_OVER_FLOW) { /* check for overflow */
298 return_max:
299 		lux = TSL2583_LUX_CALC_OVER_FLOW;
300 	}
301 
302 	/* Update the structure with the latest VALID lux. */
303 	chip->als_cur_info.lux = lux;
304 	ret = lux;
305 
306 done:
307 	return ret;
308 }
309 
310 /*
311  * Obtain single reading and calculate the als_gain_trim (later used
312  * to derive actual lux).
313  * Return updated gain_trim value.
314  */
315 static int tsl2583_als_calibrate(struct iio_dev *indio_dev)
316 {
317 	struct tsl2583_chip *chip = iio_priv(indio_dev);
318 	unsigned int gain_trim_val;
319 	int ret;
320 	int lux_val;
321 
322 	ret = i2c_smbus_read_byte_data(chip->client,
323 				       TSL2583_CMD_REG | TSL2583_CNTRL);
324 	if (ret < 0) {
325 		dev_err(&chip->client->dev,
326 			"%s: failed to read from the CNTRL register\n",
327 			__func__);
328 		return ret;
329 	}
330 
331 	if ((ret & (TSL2583_CNTL_ADC_ENBL | TSL2583_CNTL_PWR_ON))
332 			!= (TSL2583_CNTL_ADC_ENBL | TSL2583_CNTL_PWR_ON)) {
333 		dev_err(&chip->client->dev,
334 			"%s: Device is not powered on and/or ADC is not enabled\n",
335 			__func__);
336 		return -EINVAL;
337 	} else if ((ret & TSL2583_STA_ADC_VALID) != TSL2583_STA_ADC_VALID) {
338 		dev_err(&chip->client->dev,
339 			"%s: The two ADC channels have not completed an integration cycle\n",
340 			__func__);
341 		return -ENODATA;
342 	}
343 
344 	lux_val = tsl2583_get_lux(indio_dev);
345 	if (lux_val < 0) {
346 		dev_err(&chip->client->dev, "%s: failed to get lux\n",
347 			__func__);
348 		return lux_val;
349 	}
350 
351 	gain_trim_val = (unsigned int)(((chip->als_settings.als_cal_target)
352 			* chip->als_settings.als_gain_trim) / lux_val);
353 	if ((gain_trim_val < 250) || (gain_trim_val > 4000)) {
354 		dev_err(&chip->client->dev,
355 			"%s: trim_val of %d is not within the range [250, 4000]\n",
356 			__func__, gain_trim_val);
357 		return -ENODATA;
358 	}
359 
360 	chip->als_settings.als_gain_trim = (int)gain_trim_val;
361 
362 	return 0;
363 }
364 
365 static int tsl2583_set_als_time(struct tsl2583_chip *chip)
366 {
367 	int als_count, als_time, ret;
368 	u8 val;
369 
370 	/* determine als integration register */
371 	als_count = (chip->als_settings.als_time * 100 + 135) / 270;
372 	if (!als_count)
373 		als_count = 1; /* ensure at least one cycle */
374 
375 	/* convert back to time (encompasses overrides) */
376 	als_time = (als_count * 27 + 5) / 10;
377 
378 	val = 256 - als_count;
379 	ret = i2c_smbus_write_byte_data(chip->client,
380 					TSL2583_CMD_REG | TSL2583_ALS_TIME,
381 					val);
382 	if (ret < 0) {
383 		dev_err(&chip->client->dev, "%s: failed to set the als time to %d\n",
384 			__func__, val);
385 		return ret;
386 	}
387 
388 	/* set chip struct re scaling and saturation */
389 	chip->als_saturation = als_count * 922; /* 90% of full scale */
390 	chip->als_time_scale = (als_time + 25) / 50;
391 
392 	return ret;
393 }
394 
395 static int tsl2583_set_als_gain(struct tsl2583_chip *chip)
396 {
397 	int ret;
398 
399 	/* Set the gain based on als_settings struct */
400 	ret = i2c_smbus_write_byte_data(chip->client,
401 					TSL2583_CMD_REG | TSL2583_GAIN,
402 					chip->als_settings.als_gain);
403 	if (ret < 0)
404 		dev_err(&chip->client->dev,
405 			"%s: failed to set the gain to %d\n", __func__,
406 			chip->als_settings.als_gain);
407 
408 	return ret;
409 }
410 
411 static int tsl2583_set_power_state(struct tsl2583_chip *chip, u8 state)
412 {
413 	int ret;
414 
415 	ret = i2c_smbus_write_byte_data(chip->client,
416 					TSL2583_CMD_REG | TSL2583_CNTRL, state);
417 	if (ret < 0)
418 		dev_err(&chip->client->dev,
419 			"%s: failed to set the power state to %d\n", __func__,
420 			state);
421 
422 	return ret;
423 }
424 
425 /*
426  * Turn the device on.
427  * Configuration must be set before calling this function.
428  */
429 static int tsl2583_chip_init_and_power_on(struct iio_dev *indio_dev)
430 {
431 	struct tsl2583_chip *chip = iio_priv(indio_dev);
432 	int ret;
433 
434 	/* Power on the device; ADC off. */
435 	ret = tsl2583_set_power_state(chip, TSL2583_CNTL_PWR_ON);
436 	if (ret < 0)
437 		return ret;
438 
439 	ret = i2c_smbus_write_byte_data(chip->client,
440 					TSL2583_CMD_REG | TSL2583_INTERRUPT,
441 					TSL2583_INTERRUPT_DISABLED);
442 	if (ret < 0) {
443 		dev_err(&chip->client->dev,
444 			"%s: failed to disable interrupts\n", __func__);
445 		return ret;
446 	}
447 
448 	ret = tsl2583_set_als_time(chip);
449 	if (ret < 0)
450 		return ret;
451 
452 	ret = tsl2583_set_als_gain(chip);
453 	if (ret < 0)
454 		return ret;
455 
456 	usleep_range(3000, 3500);
457 
458 	ret = tsl2583_set_power_state(chip, TSL2583_CNTL_PWR_ON |
459 					    TSL2583_CNTL_ADC_ENBL);
460 	if (ret < 0)
461 		return ret;
462 
463 	chip->suspended = false;
464 
465 	return ret;
466 }
467 
468 /* Sysfs Interface Functions */
469 
470 static ssize_t in_illuminance_input_target_show(struct device *dev,
471 						struct device_attribute *attr,
472 						char *buf)
473 {
474 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
475 	struct tsl2583_chip *chip = iio_priv(indio_dev);
476 	int ret;
477 
478 	mutex_lock(&chip->als_mutex);
479 	ret = sprintf(buf, "%d\n", chip->als_settings.als_cal_target);
480 	mutex_unlock(&chip->als_mutex);
481 
482 	return ret;
483 }
484 
485 static ssize_t in_illuminance_input_target_store(struct device *dev,
486 						 struct device_attribute *attr,
487 						 const char *buf, size_t len)
488 {
489 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
490 	struct tsl2583_chip *chip = iio_priv(indio_dev);
491 	int value;
492 
493 	if (kstrtoint(buf, 0, &value) || !value)
494 		return -EINVAL;
495 
496 	mutex_lock(&chip->als_mutex);
497 	chip->als_settings.als_cal_target = value;
498 	mutex_unlock(&chip->als_mutex);
499 
500 	return len;
501 }
502 
503 static ssize_t in_illuminance_calibrate_store(struct device *dev,
504 					      struct device_attribute *attr,
505 					      const char *buf, size_t len)
506 {
507 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
508 	struct tsl2583_chip *chip = iio_priv(indio_dev);
509 	int value, ret;
510 
511 	if (kstrtoint(buf, 0, &value) || value != 1)
512 		return -EINVAL;
513 
514 	mutex_lock(&chip->als_mutex);
515 
516 	if (chip->suspended) {
517 		ret = -EBUSY;
518 		goto done;
519 	}
520 
521 	ret = tsl2583_als_calibrate(indio_dev);
522 	if (ret < 0)
523 		goto done;
524 
525 	ret = len;
526 done:
527 	mutex_unlock(&chip->als_mutex);
528 
529 	return ret;
530 }
531 
532 static ssize_t in_illuminance_lux_table_show(struct device *dev,
533 					     struct device_attribute *attr,
534 					     char *buf)
535 {
536 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
537 	struct tsl2583_chip *chip = iio_priv(indio_dev);
538 	unsigned int i;
539 	int offset = 0;
540 
541 	for (i = 0; i < ARRAY_SIZE(chip->als_settings.als_device_lux); i++) {
542 		offset += sprintf(buf + offset, "%u,%u,%u,",
543 				  chip->als_settings.als_device_lux[i].ratio,
544 				  chip->als_settings.als_device_lux[i].ch0,
545 				  chip->als_settings.als_device_lux[i].ch1);
546 		if (chip->als_settings.als_device_lux[i].ratio == 0) {
547 			/*
548 			 * We just printed the first "0" entry.
549 			 * Now get rid of the extra "," and break.
550 			 */
551 			offset--;
552 			break;
553 		}
554 	}
555 
556 	offset += sprintf(buf + offset, "\n");
557 
558 	return offset;
559 }
560 
561 static ssize_t in_illuminance_lux_table_store(struct device *dev,
562 					      struct device_attribute *attr,
563 					      const char *buf, size_t len)
564 {
565 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
566 	struct tsl2583_chip *chip = iio_priv(indio_dev);
567 	const unsigned int max_ints = TSL2583_MAX_LUX_TABLE_ENTRIES * 3;
568 	int value[TSL2583_MAX_LUX_TABLE_ENTRIES * 3 + 1];
569 	int ret = -EINVAL;
570 	unsigned int n;
571 
572 	mutex_lock(&chip->als_mutex);
573 
574 	get_options(buf, ARRAY_SIZE(value), value);
575 
576 	/*
577 	 * We now have an array of ints starting at value[1], and
578 	 * enumerated by value[0].
579 	 * We expect each group of three ints is one table entry,
580 	 * and the last table entry is all 0.
581 	 */
582 	n = value[0];
583 	if ((n % 3) || n < 6 || n > max_ints) {
584 		dev_err(dev,
585 			"%s: The number of entries in the lux table must be a multiple of 3 and within the range [6, %d]\n",
586 			__func__, max_ints);
587 		goto done;
588 	}
589 	if ((value[n - 2] | value[n - 1] | value[n]) != 0) {
590 		dev_err(dev, "%s: The last 3 entries in the lux table must be zeros.\n",
591 			__func__);
592 		goto done;
593 	}
594 
595 	memcpy(chip->als_settings.als_device_lux, &value[1],
596 	       value[0] * sizeof(value[1]));
597 
598 	ret = len;
599 
600 done:
601 	mutex_unlock(&chip->als_mutex);
602 
603 	return ret;
604 }
605 
606 static IIO_CONST_ATTR(in_illuminance_calibscale_available, "1 8 16 111");
607 static IIO_CONST_ATTR(in_illuminance_integration_time_available,
608 		      "0.000050 0.000100 0.000150 0.000200 0.000250 0.000300 0.000350 0.000400 0.000450 0.000500 0.000550 0.000600 0.000650");
609 static IIO_DEVICE_ATTR_RW(in_illuminance_input_target, 0);
610 static IIO_DEVICE_ATTR_WO(in_illuminance_calibrate, 0);
611 static IIO_DEVICE_ATTR_RW(in_illuminance_lux_table, 0);
612 
613 static struct attribute *sysfs_attrs_ctrl[] = {
614 	&iio_const_attr_in_illuminance_calibscale_available.dev_attr.attr,
615 	&iio_const_attr_in_illuminance_integration_time_available.dev_attr.attr,
616 	&iio_dev_attr_in_illuminance_input_target.dev_attr.attr,
617 	&iio_dev_attr_in_illuminance_calibrate.dev_attr.attr,
618 	&iio_dev_attr_in_illuminance_lux_table.dev_attr.attr,
619 	NULL
620 };
621 
622 static const struct attribute_group tsl2583_attribute_group = {
623 	.attrs = sysfs_attrs_ctrl,
624 };
625 
626 static const struct iio_chan_spec tsl2583_channels[] = {
627 	{
628 		.type = IIO_LIGHT,
629 		.modified = 1,
630 		.channel2 = IIO_MOD_LIGHT_IR,
631 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
632 	},
633 	{
634 		.type = IIO_LIGHT,
635 		.modified = 1,
636 		.channel2 = IIO_MOD_LIGHT_BOTH,
637 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
638 	},
639 	{
640 		.type = IIO_LIGHT,
641 		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
642 				      BIT(IIO_CHAN_INFO_CALIBBIAS) |
643 				      BIT(IIO_CHAN_INFO_CALIBSCALE) |
644 				      BIT(IIO_CHAN_INFO_INT_TIME),
645 	},
646 };
647 
648 static int tsl2583_read_raw(struct iio_dev *indio_dev,
649 			    struct iio_chan_spec const *chan,
650 			    int *val, int *val2, long mask)
651 {
652 	struct tsl2583_chip *chip = iio_priv(indio_dev);
653 	int ret = -EINVAL;
654 
655 	mutex_lock(&chip->als_mutex);
656 
657 	if (chip->suspended) {
658 		ret = -EBUSY;
659 		goto read_done;
660 	}
661 
662 	switch (mask) {
663 	case IIO_CHAN_INFO_RAW:
664 		if (chan->type == IIO_LIGHT) {
665 			ret = tsl2583_get_lux(indio_dev);
666 			if (ret < 0)
667 				goto read_done;
668 
669 			/*
670 			 * From page 20 of the TSL2581, TSL2583 data
671 			 * sheet (TAOS134 − MARCH 2011):
672 			 *
673 			 * One of the photodiodes (channel 0) is
674 			 * sensitive to both visible and infrared light,
675 			 * while the second photodiode (channel 1) is
676 			 * sensitive primarily to infrared light.
677 			 */
678 			if (chan->channel2 == IIO_MOD_LIGHT_BOTH)
679 				*val = chip->als_cur_info.als_ch0;
680 			else
681 				*val = chip->als_cur_info.als_ch1;
682 
683 			ret = IIO_VAL_INT;
684 		}
685 		break;
686 	case IIO_CHAN_INFO_PROCESSED:
687 		if (chan->type == IIO_LIGHT) {
688 			ret = tsl2583_get_lux(indio_dev);
689 			if (ret < 0)
690 				goto read_done;
691 
692 			*val = ret;
693 			ret = IIO_VAL_INT;
694 		}
695 		break;
696 	case IIO_CHAN_INFO_CALIBBIAS:
697 		if (chan->type == IIO_LIGHT) {
698 			*val = chip->als_settings.als_gain_trim;
699 			ret = IIO_VAL_INT;
700 		}
701 		break;
702 	case IIO_CHAN_INFO_CALIBSCALE:
703 		if (chan->type == IIO_LIGHT) {
704 			*val = gainadj[chip->als_settings.als_gain].mean;
705 			ret = IIO_VAL_INT;
706 		}
707 		break;
708 	case IIO_CHAN_INFO_INT_TIME:
709 		if (chan->type == IIO_LIGHT) {
710 			*val = 0;
711 			*val2 = chip->als_settings.als_time;
712 			ret = IIO_VAL_INT_PLUS_MICRO;
713 		}
714 		break;
715 	default:
716 		break;
717 	}
718 
719 read_done:
720 	mutex_unlock(&chip->als_mutex);
721 
722 	return ret;
723 }
724 
725 static int tsl2583_write_raw(struct iio_dev *indio_dev,
726 			     struct iio_chan_spec const *chan,
727 			     int val, int val2, long mask)
728 {
729 	struct tsl2583_chip *chip = iio_priv(indio_dev);
730 	int ret = -EINVAL;
731 
732 	mutex_lock(&chip->als_mutex);
733 
734 	if (chip->suspended) {
735 		ret = -EBUSY;
736 		goto write_done;
737 	}
738 
739 	switch (mask) {
740 	case IIO_CHAN_INFO_CALIBBIAS:
741 		if (chan->type == IIO_LIGHT) {
742 			chip->als_settings.als_gain_trim = val;
743 			ret = 0;
744 		}
745 		break;
746 	case IIO_CHAN_INFO_CALIBSCALE:
747 		if (chan->type == IIO_LIGHT) {
748 			unsigned int i;
749 
750 			for (i = 0; i < ARRAY_SIZE(gainadj); i++) {
751 				if (gainadj[i].mean == val) {
752 					chip->als_settings.als_gain = i;
753 					ret = tsl2583_set_als_gain(chip);
754 					break;
755 				}
756 			}
757 		}
758 		break;
759 	case IIO_CHAN_INFO_INT_TIME:
760 		if (chan->type == IIO_LIGHT && !val && val2 >= 50 &&
761 		    val2 <= 650 && !(val2 % 50)) {
762 			chip->als_settings.als_time = val2;
763 			ret = tsl2583_set_als_time(chip);
764 		}
765 		break;
766 	default:
767 		break;
768 	}
769 
770 write_done:
771 	mutex_unlock(&chip->als_mutex);
772 
773 	return ret;
774 }
775 
776 static const struct iio_info tsl2583_info = {
777 	.attrs = &tsl2583_attribute_group,
778 	.driver_module = THIS_MODULE,
779 	.read_raw = tsl2583_read_raw,
780 	.write_raw = tsl2583_write_raw,
781 };
782 
783 static int tsl2583_probe(struct i2c_client *clientp,
784 			 const struct i2c_device_id *idp)
785 {
786 	int ret;
787 	struct tsl2583_chip *chip;
788 	struct iio_dev *indio_dev;
789 
790 	if (!i2c_check_functionality(clientp->adapter,
791 				     I2C_FUNC_SMBUS_BYTE_DATA)) {
792 		dev_err(&clientp->dev, "%s: i2c smbus byte data functionality is unsupported\n",
793 			__func__);
794 		return -EOPNOTSUPP;
795 	}
796 
797 	indio_dev = devm_iio_device_alloc(&clientp->dev, sizeof(*chip));
798 	if (!indio_dev)
799 		return -ENOMEM;
800 
801 	chip = iio_priv(indio_dev);
802 	chip->client = clientp;
803 	i2c_set_clientdata(clientp, indio_dev);
804 
805 	mutex_init(&chip->als_mutex);
806 	chip->suspended = true;
807 
808 	ret = i2c_smbus_read_byte_data(clientp,
809 				       TSL2583_CMD_REG | TSL2583_CHIPID);
810 	if (ret < 0) {
811 		dev_err(&clientp->dev,
812 			"%s: failed to read the chip ID register\n", __func__);
813 		return ret;
814 	}
815 
816 	if ((ret & TSL2583_CHIP_ID_MASK) != TSL2583_CHIP_ID) {
817 		dev_err(&clientp->dev, "%s: received an unknown chip ID %x\n",
818 			__func__, ret);
819 		return -EINVAL;
820 	}
821 
822 	indio_dev->info = &tsl2583_info;
823 	indio_dev->channels = tsl2583_channels;
824 	indio_dev->num_channels = ARRAY_SIZE(tsl2583_channels);
825 	indio_dev->dev.parent = &clientp->dev;
826 	indio_dev->modes = INDIO_DIRECT_MODE;
827 	indio_dev->name = chip->client->name;
828 
829 	ret = devm_iio_device_register(indio_dev->dev.parent, indio_dev);
830 	if (ret) {
831 		dev_err(&clientp->dev, "%s: iio registration failed\n",
832 			__func__);
833 		return ret;
834 	}
835 
836 	/* Load up the V2 defaults (these are hard coded defaults for now) */
837 	tsl2583_defaults(chip);
838 
839 	/* Make sure the chip is on */
840 	ret = tsl2583_chip_init_and_power_on(indio_dev);
841 	if (ret < 0)
842 		return ret;
843 
844 	dev_info(&clientp->dev, "Light sensor found.\n");
845 
846 	return 0;
847 }
848 
849 static int __maybe_unused tsl2583_suspend(struct device *dev)
850 {
851 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
852 	struct tsl2583_chip *chip = iio_priv(indio_dev);
853 	int ret;
854 
855 	mutex_lock(&chip->als_mutex);
856 
857 	ret = tsl2583_set_power_state(chip, TSL2583_CNTL_PWR_OFF);
858 	chip->suspended = true;
859 
860 	mutex_unlock(&chip->als_mutex);
861 
862 	return ret;
863 }
864 
865 static int __maybe_unused tsl2583_resume(struct device *dev)
866 {
867 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
868 	struct tsl2583_chip *chip = iio_priv(indio_dev);
869 	int ret;
870 
871 	mutex_lock(&chip->als_mutex);
872 
873 	ret = tsl2583_chip_init_and_power_on(indio_dev);
874 
875 	mutex_unlock(&chip->als_mutex);
876 
877 	return ret;
878 }
879 
880 static SIMPLE_DEV_PM_OPS(tsl2583_pm_ops, tsl2583_suspend, tsl2583_resume);
881 
882 static struct i2c_device_id tsl2583_idtable[] = {
883 	{ "tsl2580", 0 },
884 	{ "tsl2581", 1 },
885 	{ "tsl2583", 2 },
886 	{}
887 };
888 MODULE_DEVICE_TABLE(i2c, tsl2583_idtable);
889 
890 static const struct of_device_id tsl2583_of_match[] = {
891 	{ .compatible = "amstaos,tsl2580", },
892 	{ .compatible = "amstaos,tsl2581", },
893 	{ .compatible = "amstaos,tsl2583", },
894 	{ },
895 };
896 MODULE_DEVICE_TABLE(of, tsl2583_of_match);
897 
898 /* Driver definition */
899 static struct i2c_driver tsl2583_driver = {
900 	.driver = {
901 		.name = "tsl2583",
902 		.pm = &tsl2583_pm_ops,
903 		.of_match_table = tsl2583_of_match,
904 	},
905 	.id_table = tsl2583_idtable,
906 	.probe = tsl2583_probe,
907 };
908 module_i2c_driver(tsl2583_driver);
909 
910 MODULE_AUTHOR("J. August Brenner <jbrenner@taosinc.com>");
911 MODULE_AUTHOR("Brian Masney <masneyb@onstation.org>");
912 MODULE_DESCRIPTION("TAOS tsl2583 ambient light sensor driver");
913 MODULE_LICENSE("GPL");
914