xref: /linux/drivers/iio/light/as73211.c (revision 4b660dbd9ee2059850fd30e0df420ca7a38a1856)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Support for AMS AS73211 JENCOLOR(R) Digital XYZ Sensor and AMS AS7331
4  * UVA, UVB and UVC (DUV) Ultraviolet Sensor
5  *
6  * Author: Christian Eggers <ceggers@arri.de>
7  *
8  * Copyright (c) 2020 ARRI Lighting
9  *
10  * Color light sensor with 16-bit channels for x, y, z and temperature);
11  * 7-bit I2C slave address 0x74 .. 0x77.
12  *
13  * Datasheets:
14  * AS73211: https://ams.com/documents/20143/36005/AS73211_DS000556_3-01.pdf
15  * AS7331: https://ams.com/documents/20143/9106314/AS7331_DS001047_4-00.pdf
16  */
17 
18 #include <linux/bitfield.h>
19 #include <linux/completion.h>
20 #include <linux/delay.h>
21 #include <linux/i2c.h>
22 #include <linux/iio/buffer.h>
23 #include <linux/iio/iio.h>
24 #include <linux/iio/sysfs.h>
25 #include <linux/iio/trigger_consumer.h>
26 #include <linux/iio/triggered_buffer.h>
27 #include <linux/module.h>
28 #include <linux/mutex.h>
29 #include <linux/pm.h>
30 #include <linux/units.h>
31 
32 #define AS73211_DRV_NAME "as73211"
33 
34 /* AS73211 configuration registers */
35 #define AS73211_REG_OSR    0x0
36 #define AS73211_REG_AGEN   0x2
37 #define AS73211_REG_CREG1  0x6
38 #define AS73211_REG_CREG2  0x7
39 #define AS73211_REG_CREG3  0x8
40 
41 /* AS73211 output register bank */
42 #define AS73211_OUT_OSR_STATUS    0
43 #define AS73211_OUT_TEMP          1
44 #define AS73211_OUT_MRES1         2
45 #define AS73211_OUT_MRES2         3
46 #define AS73211_OUT_MRES3         4
47 
48 #define AS73211_OSR_SS            BIT(7)
49 #define AS73211_OSR_PD            BIT(6)
50 #define AS73211_OSR_SW_RES        BIT(3)
51 #define AS73211_OSR_DOS_MASK      GENMASK(2, 0)
52 #define AS73211_OSR_DOS_CONFIG    FIELD_PREP(AS73211_OSR_DOS_MASK, 0x2)
53 #define AS73211_OSR_DOS_MEASURE   FIELD_PREP(AS73211_OSR_DOS_MASK, 0x3)
54 
55 #define AS73211_AGEN_DEVID_MASK   GENMASK(7, 4)
56 #define AS73211_AGEN_DEVID(x)     FIELD_PREP(AS73211_AGEN_DEVID_MASK, (x))
57 #define AS73211_AGEN_MUT_MASK     GENMASK(3, 0)
58 #define AS73211_AGEN_MUT(x)       FIELD_PREP(AS73211_AGEN_MUT_MASK, (x))
59 
60 #define AS73211_CREG1_GAIN_MASK   GENMASK(7, 4)
61 #define AS73211_CREG1_GAIN_1      11
62 #define AS73211_CREG1_TIME_MASK   GENMASK(3, 0)
63 
64 #define AS73211_CREG3_CCLK_MASK   GENMASK(1, 0)
65 
66 #define AS73211_OSR_STATUS_OUTCONVOF  BIT(15)
67 #define AS73211_OSR_STATUS_MRESOF     BIT(14)
68 #define AS73211_OSR_STATUS_ADCOF      BIT(13)
69 #define AS73211_OSR_STATUS_LDATA      BIT(12)
70 #define AS73211_OSR_STATUS_NDATA      BIT(11)
71 #define AS73211_OSR_STATUS_NOTREADY   BIT(10)
72 
73 #define AS73211_SAMPLE_FREQ_BASE      1024000
74 
75 #define AS73211_SAMPLE_TIME_NUM       15
76 #define AS73211_SAMPLE_TIME_MAX_MS    BIT(AS73211_SAMPLE_TIME_NUM - 1)
77 
78 /* Available sample frequencies are 1.024MHz multiplied by powers of two. */
79 static const int as73211_samp_freq_avail[] = {
80 	AS73211_SAMPLE_FREQ_BASE * 1,
81 	AS73211_SAMPLE_FREQ_BASE * 2,
82 	AS73211_SAMPLE_FREQ_BASE * 4,
83 	AS73211_SAMPLE_FREQ_BASE * 8,
84 };
85 
86 static const int as73211_hardwaregain_avail[] = {
87 	1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048,
88 };
89 
90 struct as73211_data;
91 
92 /**
93  * struct as73211_spec_dev_data - device-specific data
94  * @intensity_scale:  Function to retrieve intensity scale values.
95  * @channels:          Device channels.
96  * @num_channels:     Number of channels of the device.
97  */
98 struct as73211_spec_dev_data {
99 	int (*intensity_scale)(struct as73211_data *data, int chan, int *val, int *val2);
100 	struct iio_chan_spec const *channels;
101 	int num_channels;
102 };
103 
104 /**
105  * struct as73211_data - Instance data for one AS73211
106  * @client: I2C client.
107  * @osr:    Cached Operational State Register.
108  * @creg1:  Cached Configuration Register 1.
109  * @creg2:  Cached Configuration Register 2.
110  * @creg3:  Cached Configuration Register 3.
111  * @mutex:  Keeps cached registers in sync with the device.
112  * @completion: Completion to wait for interrupt.
113  * @int_time_avail: Available integration times (depend on sampling frequency).
114  * @spec_dev: device-specific configuration.
115  */
116 struct as73211_data {
117 	struct i2c_client *client;
118 	u8 osr;
119 	u8 creg1;
120 	u8 creg2;
121 	u8 creg3;
122 	struct mutex mutex;
123 	struct completion completion;
124 	int int_time_avail[AS73211_SAMPLE_TIME_NUM * 2];
125 	const struct as73211_spec_dev_data *spec_dev;
126 };
127 
128 #define AS73211_COLOR_CHANNEL(_color, _si, _addr) { \
129 	.type = IIO_INTENSITY, \
130 	.modified = 1, \
131 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), \
132 	.info_mask_shared_by_type = \
133 		BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
134 		BIT(IIO_CHAN_INFO_HARDWAREGAIN) | \
135 		BIT(IIO_CHAN_INFO_INT_TIME), \
136 	.info_mask_shared_by_type_available = \
137 		BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
138 		BIT(IIO_CHAN_INFO_HARDWAREGAIN) | \
139 		BIT(IIO_CHAN_INFO_INT_TIME), \
140 	.channel2 = IIO_MOD_##_color, \
141 	.address = _addr, \
142 	.scan_index = _si, \
143 	.scan_type = { \
144 		.sign = 'u', \
145 		.realbits = 16, \
146 		.storagebits = 16, \
147 		.endianness = IIO_LE, \
148 	}, \
149 }
150 
151 #define AS73211_OFFSET_TEMP_INT    (-66)
152 #define AS73211_OFFSET_TEMP_MICRO  900000
153 #define AS73211_SCALE_TEMP_INT     0
154 #define AS73211_SCALE_TEMP_MICRO   50000
155 
156 #define AS73211_SCALE_X 277071108  /* nW/m^2 */
157 #define AS73211_SCALE_Y 298384270  /* nW/m^2 */
158 #define AS73211_SCALE_Z 160241927  /* nW/m^2 */
159 
160 #define AS7331_SCALE_UVA 340000  /* nW/cm^2 */
161 #define AS7331_SCALE_UVB 378000  /* nW/cm^2 */
162 #define AS7331_SCALE_UVC 166000  /* nW/cm^2 */
163 
164 /* Channel order MUST match devices result register order */
165 #define AS73211_SCAN_INDEX_TEMP 0
166 #define AS73211_SCAN_INDEX_X    1
167 #define AS73211_SCAN_INDEX_Y    2
168 #define AS73211_SCAN_INDEX_Z    3
169 #define AS73211_SCAN_INDEX_TS   4
170 
171 #define AS73211_SCAN_MASK_COLOR ( \
172 	BIT(AS73211_SCAN_INDEX_X) |   \
173 	BIT(AS73211_SCAN_INDEX_Y) |   \
174 	BIT(AS73211_SCAN_INDEX_Z))
175 
176 #define AS73211_SCAN_MASK_ALL (    \
177 	BIT(AS73211_SCAN_INDEX_TEMP) | \
178 	AS73211_SCAN_MASK_COLOR)
179 
180 static const struct iio_chan_spec as73211_channels[] = {
181 	{
182 		.type = IIO_TEMP,
183 		.info_mask_separate =
184 			BIT(IIO_CHAN_INFO_RAW) |
185 			BIT(IIO_CHAN_INFO_OFFSET) |
186 			BIT(IIO_CHAN_INFO_SCALE),
187 		.address = AS73211_OUT_TEMP,
188 		.scan_index = AS73211_SCAN_INDEX_TEMP,
189 		.scan_type = {
190 			.sign = 'u',
191 			.realbits = 16,
192 			.storagebits = 16,
193 			.endianness = IIO_LE,
194 		}
195 	},
196 	AS73211_COLOR_CHANNEL(X, AS73211_SCAN_INDEX_X, AS73211_OUT_MRES1),
197 	AS73211_COLOR_CHANNEL(Y, AS73211_SCAN_INDEX_Y, AS73211_OUT_MRES2),
198 	AS73211_COLOR_CHANNEL(Z, AS73211_SCAN_INDEX_Z, AS73211_OUT_MRES3),
199 	IIO_CHAN_SOFT_TIMESTAMP(AS73211_SCAN_INDEX_TS),
200 };
201 
202 static const struct iio_chan_spec as7331_channels[] = {
203 	{
204 		.type = IIO_TEMP,
205 		.info_mask_separate =
206 			BIT(IIO_CHAN_INFO_RAW) |
207 			BIT(IIO_CHAN_INFO_OFFSET) |
208 			BIT(IIO_CHAN_INFO_SCALE),
209 		.address = AS73211_OUT_TEMP,
210 		.scan_index = AS73211_SCAN_INDEX_TEMP,
211 		.scan_type = {
212 			.sign = 'u',
213 			.realbits = 16,
214 			.storagebits = 16,
215 			.endianness = IIO_LE,
216 		}
217 	},
218 	AS73211_COLOR_CHANNEL(LIGHT_UVA, AS73211_SCAN_INDEX_X, AS73211_OUT_MRES1),
219 	AS73211_COLOR_CHANNEL(LIGHT_UVB, AS73211_SCAN_INDEX_Y, AS73211_OUT_MRES2),
220 	AS73211_COLOR_CHANNEL(LIGHT_DUV, AS73211_SCAN_INDEX_Z, AS73211_OUT_MRES3),
221 	IIO_CHAN_SOFT_TIMESTAMP(AS73211_SCAN_INDEX_TS),
222 };
223 
224 static unsigned int as73211_integration_time_1024cyc(struct as73211_data *data)
225 {
226 	/*
227 	 * Return integration time in units of 1024 clock cycles. Integration time
228 	 * in CREG1 is in powers of 2 (x 1024 cycles).
229 	 */
230 	return BIT(FIELD_GET(AS73211_CREG1_TIME_MASK, data->creg1));
231 }
232 
233 static unsigned int as73211_integration_time_us(struct as73211_data *data,
234 						 unsigned int integration_time_1024cyc)
235 {
236 	/*
237 	 * f_samp is configured in CREG3 in powers of 2 (x 1.024 MHz)
238 	 * t_cycl is configured in CREG1 in powers of 2 (x 1024 cycles)
239 	 * t_int_us = 1 / (f_samp) * t_cycl * US_PER_SEC
240 	 *          = 1 / (2^CREG3_CCLK * 1,024,000) * 2^CREG1_CYCLES * 1,024 * US_PER_SEC
241 	 *          = 2^(-CREG3_CCLK) * 2^CREG1_CYCLES * 1,000
242 	 * In order to get rid of negative exponents, we extend the "fraction"
243 	 * by 2^3 (CREG3_CCLK,max = 3)
244 	 * t_int_us = 2^(3-CREG3_CCLK) * 2^CREG1_CYCLES * 125
245 	 */
246 	return BIT(3 - FIELD_GET(AS73211_CREG3_CCLK_MASK, data->creg3)) *
247 		integration_time_1024cyc * 125;
248 }
249 
250 static void as73211_integration_time_calc_avail(struct as73211_data *data)
251 {
252 	int i;
253 
254 	for (i = 0; i < ARRAY_SIZE(data->int_time_avail) / 2; i++) {
255 		unsigned int time_us = as73211_integration_time_us(data, BIT(i));
256 
257 		data->int_time_avail[i * 2 + 0] = time_us / USEC_PER_SEC;
258 		data->int_time_avail[i * 2 + 1] = time_us % USEC_PER_SEC;
259 	}
260 }
261 
262 static unsigned int as73211_gain(struct as73211_data *data)
263 {
264 	/* gain can be calculated from CREG1 as 2^(11 - CREG1_GAIN) */
265 	return BIT(AS73211_CREG1_GAIN_1 - FIELD_GET(AS73211_CREG1_GAIN_MASK, data->creg1));
266 }
267 
268 /* must be called with as73211_data::mutex held. */
269 static int as73211_req_data(struct as73211_data *data)
270 {
271 	unsigned int time_us = as73211_integration_time_us(data,
272 							    as73211_integration_time_1024cyc(data));
273 	struct device *dev = &data->client->dev;
274 	union i2c_smbus_data smbus_data;
275 	u16 osr_status;
276 	int ret;
277 
278 	if (data->client->irq)
279 		reinit_completion(&data->completion);
280 
281 	/*
282 	 * During measurement, there should be no traffic on the i2c bus as the
283 	 * electrical noise would disturb the measurement process.
284 	 */
285 	i2c_lock_bus(data->client->adapter, I2C_LOCK_SEGMENT);
286 
287 	data->osr &= ~AS73211_OSR_DOS_MASK;
288 	data->osr |= AS73211_OSR_DOS_MEASURE | AS73211_OSR_SS;
289 
290 	smbus_data.byte = data->osr;
291 	ret = __i2c_smbus_xfer(data->client->adapter, data->client->addr,
292 			data->client->flags, I2C_SMBUS_WRITE,
293 			AS73211_REG_OSR, I2C_SMBUS_BYTE_DATA, &smbus_data);
294 	if (ret < 0) {
295 		i2c_unlock_bus(data->client->adapter, I2C_LOCK_SEGMENT);
296 		return ret;
297 	}
298 
299 	/*
300 	 * Reset AS73211_OSR_SS (is self clearing) in order to avoid unintentional
301 	 * triggering of further measurements later.
302 	 */
303 	data->osr &= ~AS73211_OSR_SS;
304 
305 	/*
306 	 * Add 33% extra margin for the timeout. fclk,min = fclk,typ - 27%.
307 	 */
308 	time_us += time_us / 3;
309 	if (data->client->irq) {
310 		ret = wait_for_completion_timeout(&data->completion, usecs_to_jiffies(time_us));
311 		if (!ret) {
312 			dev_err(dev, "timeout waiting for READY IRQ\n");
313 			i2c_unlock_bus(data->client->adapter, I2C_LOCK_SEGMENT);
314 			return -ETIMEDOUT;
315 		}
316 	} else {
317 		/* Wait integration time */
318 		usleep_range(time_us, 2 * time_us);
319 	}
320 
321 	i2c_unlock_bus(data->client->adapter, I2C_LOCK_SEGMENT);
322 
323 	ret = i2c_smbus_read_word_data(data->client, AS73211_OUT_OSR_STATUS);
324 	if (ret < 0)
325 		return ret;
326 
327 	osr_status = ret;
328 	if (osr_status != (AS73211_OSR_DOS_MEASURE | AS73211_OSR_STATUS_NDATA)) {
329 		if (osr_status & AS73211_OSR_SS) {
330 			dev_err(dev, "%s() Measurement has not stopped\n", __func__);
331 			return -ETIME;
332 		}
333 		if (osr_status & AS73211_OSR_STATUS_NOTREADY) {
334 			dev_err(dev, "%s() Data is not ready\n", __func__);
335 			return -ENODATA;
336 		}
337 		if (!(osr_status & AS73211_OSR_STATUS_NDATA)) {
338 			dev_err(dev, "%s() No new data available\n", __func__);
339 			return -ENODATA;
340 		}
341 		if (osr_status & AS73211_OSR_STATUS_LDATA) {
342 			dev_err(dev, "%s() Result buffer overrun\n", __func__);
343 			return -ENOBUFS;
344 		}
345 		if (osr_status & AS73211_OSR_STATUS_ADCOF) {
346 			dev_err(dev, "%s() ADC overflow\n", __func__);
347 			return -EOVERFLOW;
348 		}
349 		if (osr_status & AS73211_OSR_STATUS_MRESOF) {
350 			dev_err(dev, "%s() Measurement result overflow\n", __func__);
351 			return -EOVERFLOW;
352 		}
353 		if (osr_status & AS73211_OSR_STATUS_OUTCONVOF) {
354 			dev_err(dev, "%s() Timer overflow\n", __func__);
355 			return -EOVERFLOW;
356 		}
357 		dev_err(dev, "%s() Unexpected status value\n", __func__);
358 		return -EIO;
359 	}
360 
361 	return 0;
362 }
363 
364 static int as73211_intensity_scale(struct as73211_data *data, int chan,
365 				   int *val, int *val2)
366 {
367 	switch (chan) {
368 	case IIO_MOD_X:
369 		*val = AS73211_SCALE_X;
370 		break;
371 	case IIO_MOD_Y:
372 		*val = AS73211_SCALE_Y;
373 		break;
374 	case IIO_MOD_Z:
375 		*val = AS73211_SCALE_Z;
376 		break;
377 	default:
378 		return -EINVAL;
379 	}
380 	*val2 = as73211_integration_time_1024cyc(data) * as73211_gain(data);
381 
382 	return IIO_VAL_FRACTIONAL;
383 }
384 
385 static int as7331_intensity_scale(struct as73211_data *data, int chan,
386 				  int *val, int *val2)
387 {
388 	switch (chan) {
389 	case IIO_MOD_LIGHT_UVA:
390 		*val = AS7331_SCALE_UVA;
391 		break;
392 	case IIO_MOD_LIGHT_UVB:
393 		*val = AS7331_SCALE_UVB;
394 		break;
395 	case IIO_MOD_LIGHT_DUV:
396 		*val = AS7331_SCALE_UVC;
397 		break;
398 	default:
399 		return -EINVAL;
400 	}
401 	*val2 = as73211_integration_time_1024cyc(data) * as73211_gain(data);
402 
403 	return IIO_VAL_FRACTIONAL;
404 }
405 
406 static int as73211_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
407 			     int *val, int *val2, long mask)
408 {
409 	struct as73211_data *data = iio_priv(indio_dev);
410 
411 	switch (mask) {
412 	case IIO_CHAN_INFO_RAW: {
413 		int ret;
414 
415 		ret = iio_device_claim_direct_mode(indio_dev);
416 		if (ret < 0)
417 			return ret;
418 
419 		ret = as73211_req_data(data);
420 		if (ret < 0) {
421 			iio_device_release_direct_mode(indio_dev);
422 			return ret;
423 		}
424 
425 		ret = i2c_smbus_read_word_data(data->client, chan->address);
426 		iio_device_release_direct_mode(indio_dev);
427 		if (ret < 0)
428 			return ret;
429 
430 		*val = ret;
431 		return IIO_VAL_INT;
432 	}
433 	case IIO_CHAN_INFO_OFFSET:
434 		*val = AS73211_OFFSET_TEMP_INT;
435 		*val2 = AS73211_OFFSET_TEMP_MICRO;
436 		return IIO_VAL_INT_PLUS_MICRO;
437 
438 	case IIO_CHAN_INFO_SCALE:
439 		switch (chan->type) {
440 		case IIO_TEMP:
441 			*val = AS73211_SCALE_TEMP_INT;
442 			*val2 = AS73211_SCALE_TEMP_MICRO;
443 			return IIO_VAL_INT_PLUS_MICRO;
444 
445 		case IIO_INTENSITY:
446 			return data->spec_dev->intensity_scale(data, chan->channel2,
447 							       val, val2);
448 
449 		default:
450 			return -EINVAL;
451 		}
452 
453 	case IIO_CHAN_INFO_SAMP_FREQ:
454 		/* f_samp is configured in CREG3 in powers of 2 (x 1.024 MHz) */
455 		*val = BIT(FIELD_GET(AS73211_CREG3_CCLK_MASK, data->creg3)) *
456 			AS73211_SAMPLE_FREQ_BASE;
457 		return IIO_VAL_INT;
458 
459 	case IIO_CHAN_INFO_HARDWAREGAIN:
460 		*val = as73211_gain(data);
461 		return IIO_VAL_INT;
462 
463 	case IIO_CHAN_INFO_INT_TIME: {
464 		unsigned int time_us;
465 
466 		mutex_lock(&data->mutex);
467 		time_us = as73211_integration_time_us(data, as73211_integration_time_1024cyc(data));
468 		mutex_unlock(&data->mutex);
469 		*val = time_us / USEC_PER_SEC;
470 		*val2 = time_us % USEC_PER_SEC;
471 		return IIO_VAL_INT_PLUS_MICRO;
472 
473 	default:
474 		return -EINVAL;
475 	}}
476 }
477 
478 static int as73211_read_avail(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
479 			       const int **vals, int *type, int *length, long mask)
480 {
481 	struct as73211_data *data = iio_priv(indio_dev);
482 
483 	switch (mask) {
484 	case IIO_CHAN_INFO_SAMP_FREQ:
485 		*length = ARRAY_SIZE(as73211_samp_freq_avail);
486 		*vals = as73211_samp_freq_avail;
487 		*type = IIO_VAL_INT;
488 		return IIO_AVAIL_LIST;
489 
490 	case IIO_CHAN_INFO_HARDWAREGAIN:
491 		*length = ARRAY_SIZE(as73211_hardwaregain_avail);
492 		*vals = as73211_hardwaregain_avail;
493 		*type = IIO_VAL_INT;
494 		return IIO_AVAIL_LIST;
495 
496 	case IIO_CHAN_INFO_INT_TIME:
497 		*length = ARRAY_SIZE(data->int_time_avail);
498 		*vals = data->int_time_avail;
499 		*type = IIO_VAL_INT_PLUS_MICRO;
500 		return IIO_AVAIL_LIST;
501 
502 	default:
503 		return -EINVAL;
504 	}
505 }
506 
507 static int _as73211_write_raw(struct iio_dev *indio_dev,
508 			       struct iio_chan_spec const *chan __always_unused,
509 			       int val, int val2, long mask)
510 {
511 	struct as73211_data *data = iio_priv(indio_dev);
512 	int ret;
513 
514 	switch (mask) {
515 	case IIO_CHAN_INFO_SAMP_FREQ: {
516 		int reg_bits, freq_kHz = val / HZ_PER_KHZ;  /* 1024, 2048, ... */
517 
518 		/* val must be 1024 * 2^x */
519 		if (val < 0 || (freq_kHz * HZ_PER_KHZ) != val ||
520 				!is_power_of_2(freq_kHz) || val2)
521 			return -EINVAL;
522 
523 		/* f_samp is configured in CREG3 in powers of 2 (x 1.024 MHz (=2^10)) */
524 		reg_bits = ilog2(freq_kHz) - 10;
525 		if (!FIELD_FIT(AS73211_CREG3_CCLK_MASK, reg_bits))
526 			return -EINVAL;
527 
528 		data->creg3 &= ~AS73211_CREG3_CCLK_MASK;
529 		data->creg3 |= FIELD_PREP(AS73211_CREG3_CCLK_MASK, reg_bits);
530 		as73211_integration_time_calc_avail(data);
531 
532 		ret = i2c_smbus_write_byte_data(data->client, AS73211_REG_CREG3, data->creg3);
533 		if (ret < 0)
534 			return ret;
535 
536 		return 0;
537 	}
538 	case IIO_CHAN_INFO_HARDWAREGAIN: {
539 		unsigned int reg_bits;
540 
541 		if (val < 0 || !is_power_of_2(val) || val2)
542 			return -EINVAL;
543 
544 		/* gain can be calculated from CREG1 as 2^(11 - CREG1_GAIN) */
545 		reg_bits = AS73211_CREG1_GAIN_1 - ilog2(val);
546 		if (!FIELD_FIT(AS73211_CREG1_GAIN_MASK, reg_bits))
547 			return -EINVAL;
548 
549 		data->creg1 &= ~AS73211_CREG1_GAIN_MASK;
550 		data->creg1 |= FIELD_PREP(AS73211_CREG1_GAIN_MASK, reg_bits);
551 
552 		ret = i2c_smbus_write_byte_data(data->client, AS73211_REG_CREG1, data->creg1);
553 		if (ret < 0)
554 			return ret;
555 
556 		return 0;
557 	}
558 	case IIO_CHAN_INFO_INT_TIME: {
559 		int val_us = val * USEC_PER_SEC + val2;
560 		int time_ms;
561 		int reg_bits;
562 
563 		/* f_samp is configured in CREG3 in powers of 2 (x 1.024 MHz) */
564 		int f_samp_1_024mhz = BIT(FIELD_GET(AS73211_CREG3_CCLK_MASK, data->creg3));
565 
566 		/*
567 		 * time_ms = time_us * US_PER_MS * f_samp_1_024mhz / MHZ_PER_HZ
568 		 *         = time_us * f_samp_1_024mhz / 1000
569 		 */
570 		time_ms = (val_us * f_samp_1_024mhz) / 1000;  /* 1 ms, 2 ms, ... (power of two) */
571 		if (time_ms < 0 || !is_power_of_2(time_ms) || time_ms > AS73211_SAMPLE_TIME_MAX_MS)
572 			return -EINVAL;
573 
574 		reg_bits = ilog2(time_ms);
575 		if (!FIELD_FIT(AS73211_CREG1_TIME_MASK, reg_bits))
576 			return -EINVAL;  /* not possible due to previous tests */
577 
578 		data->creg1 &= ~AS73211_CREG1_TIME_MASK;
579 		data->creg1 |= FIELD_PREP(AS73211_CREG1_TIME_MASK, reg_bits);
580 
581 		ret = i2c_smbus_write_byte_data(data->client, AS73211_REG_CREG1, data->creg1);
582 		if (ret < 0)
583 			return ret;
584 
585 		return 0;
586 
587 	default:
588 		return -EINVAL;
589 	}}
590 }
591 
592 static int as73211_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
593 			      int val, int val2, long mask)
594 {
595 	struct as73211_data *data = iio_priv(indio_dev);
596 	int ret;
597 
598 	mutex_lock(&data->mutex);
599 
600 	ret = iio_device_claim_direct_mode(indio_dev);
601 	if (ret < 0)
602 		goto error_unlock;
603 
604 	/* Need to switch to config mode ... */
605 	if ((data->osr & AS73211_OSR_DOS_MASK) != AS73211_OSR_DOS_CONFIG) {
606 		data->osr &= ~AS73211_OSR_DOS_MASK;
607 		data->osr |= AS73211_OSR_DOS_CONFIG;
608 
609 		ret = i2c_smbus_write_byte_data(data->client, AS73211_REG_OSR, data->osr);
610 		if (ret < 0)
611 			goto error_release;
612 	}
613 
614 	ret = _as73211_write_raw(indio_dev, chan, val, val2, mask);
615 
616 error_release:
617 	iio_device_release_direct_mode(indio_dev);
618 error_unlock:
619 	mutex_unlock(&data->mutex);
620 	return ret;
621 }
622 
623 static irqreturn_t as73211_ready_handler(int irq __always_unused, void *priv)
624 {
625 	struct as73211_data *data = iio_priv(priv);
626 
627 	complete(&data->completion);
628 
629 	return IRQ_HANDLED;
630 }
631 
632 static irqreturn_t as73211_trigger_handler(int irq __always_unused, void *p)
633 {
634 	struct iio_poll_func *pf = p;
635 	struct iio_dev *indio_dev = pf->indio_dev;
636 	struct as73211_data *data = iio_priv(indio_dev);
637 	struct {
638 		__le16 chan[4];
639 		s64 ts __aligned(8);
640 	} scan;
641 	int data_result, ret;
642 
643 	mutex_lock(&data->mutex);
644 
645 	data_result = as73211_req_data(data);
646 	if (data_result < 0 && data_result != -EOVERFLOW)
647 		goto done;  /* don't push any data for errors other than EOVERFLOW */
648 
649 	if (*indio_dev->active_scan_mask == AS73211_SCAN_MASK_ALL) {
650 		/* Optimization for reading all (color + temperature) channels */
651 		u8 addr = as73211_channels[0].address;
652 		struct i2c_msg msgs[] = {
653 			{
654 				.addr = data->client->addr,
655 				.flags = 0,
656 				.len = 1,
657 				.buf = &addr,
658 			},
659 			{
660 				.addr = data->client->addr,
661 				.flags = I2C_M_RD,
662 				.len = sizeof(scan.chan),
663 				.buf = (u8 *)&scan.chan,
664 			},
665 		};
666 
667 		ret = i2c_transfer(data->client->adapter, msgs, ARRAY_SIZE(msgs));
668 		if (ret < 0)
669 			goto done;
670 	} else {
671 		/* Optimization for reading only color channels */
672 
673 		/* AS73211 starts reading at address 2 */
674 		ret = i2c_master_recv(data->client,
675 				(char *)&scan.chan[1], 3 * sizeof(scan.chan[1]));
676 		if (ret < 0)
677 			goto done;
678 	}
679 
680 	if (data_result) {
681 		/*
682 		 * Saturate all channels (in case of overflows). Temperature channel
683 		 * is not affected by overflows.
684 		 */
685 		scan.chan[1] = cpu_to_le16(U16_MAX);
686 		scan.chan[2] = cpu_to_le16(U16_MAX);
687 		scan.chan[3] = cpu_to_le16(U16_MAX);
688 	}
689 
690 	iio_push_to_buffers_with_timestamp(indio_dev, &scan, iio_get_time_ns(indio_dev));
691 
692 done:
693 	mutex_unlock(&data->mutex);
694 	iio_trigger_notify_done(indio_dev->trig);
695 
696 	return IRQ_HANDLED;
697 }
698 
699 static const struct iio_info as73211_info = {
700 	.read_raw = as73211_read_raw,
701 	.read_avail = as73211_read_avail,
702 	.write_raw = as73211_write_raw,
703 };
704 
705 static int as73211_power(struct iio_dev *indio_dev, bool state)
706 {
707 	struct as73211_data *data = iio_priv(indio_dev);
708 	int ret;
709 
710 	mutex_lock(&data->mutex);
711 
712 	if (state)
713 		data->osr &= ~AS73211_OSR_PD;
714 	else
715 		data->osr |= AS73211_OSR_PD;
716 
717 	ret = i2c_smbus_write_byte_data(data->client, AS73211_REG_OSR, data->osr);
718 
719 	mutex_unlock(&data->mutex);
720 
721 	if (ret < 0)
722 		return ret;
723 
724 	return 0;
725 }
726 
727 static void as73211_power_disable(void *data)
728 {
729 	struct iio_dev *indio_dev = data;
730 
731 	as73211_power(indio_dev, false);
732 }
733 
734 static int as73211_probe(struct i2c_client *client)
735 {
736 	struct device *dev = &client->dev;
737 	struct as73211_data *data;
738 	struct iio_dev *indio_dev;
739 	int ret;
740 
741 	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
742 	if (!indio_dev)
743 		return -ENOMEM;
744 
745 	data = iio_priv(indio_dev);
746 	i2c_set_clientdata(client, indio_dev);
747 	data->client = client;
748 
749 	data->spec_dev = i2c_get_match_data(client);
750 	if (!data->spec_dev)
751 		return -EINVAL;
752 
753 	mutex_init(&data->mutex);
754 	init_completion(&data->completion);
755 
756 	indio_dev->info = &as73211_info;
757 	indio_dev->name = AS73211_DRV_NAME;
758 	indio_dev->channels = data->spec_dev->channels;
759 	indio_dev->num_channels = data->spec_dev->num_channels;
760 	indio_dev->modes = INDIO_DIRECT_MODE;
761 
762 	ret = i2c_smbus_read_byte_data(data->client, AS73211_REG_OSR);
763 	if (ret < 0)
764 		return ret;
765 	data->osr = ret;
766 
767 	/* reset device */
768 	data->osr |= AS73211_OSR_SW_RES;
769 	ret = i2c_smbus_write_byte_data(data->client, AS73211_REG_OSR, data->osr);
770 	if (ret < 0)
771 		return ret;
772 
773 	ret = i2c_smbus_read_byte_data(data->client, AS73211_REG_OSR);
774 	if (ret < 0)
775 		return ret;
776 	data->osr = ret;
777 
778 	/*
779 	 * Reading AGEN is only possible after reset (AGEN is not available if
780 	 * device is in measurement mode).
781 	 */
782 	ret = i2c_smbus_read_byte_data(data->client, AS73211_REG_AGEN);
783 	if (ret < 0)
784 		return ret;
785 
786 	/* At the time of writing this driver, only DEVID 2 and MUT 1 are known. */
787 	if ((ret & AS73211_AGEN_DEVID_MASK) != AS73211_AGEN_DEVID(2) ||
788 	    (ret & AS73211_AGEN_MUT_MASK) != AS73211_AGEN_MUT(1))
789 		return -ENODEV;
790 
791 	ret = i2c_smbus_read_byte_data(data->client, AS73211_REG_CREG1);
792 	if (ret < 0)
793 		return ret;
794 	data->creg1 = ret;
795 
796 	ret = i2c_smbus_read_byte_data(data->client, AS73211_REG_CREG2);
797 	if (ret < 0)
798 		return ret;
799 	data->creg2 = ret;
800 
801 	ret = i2c_smbus_read_byte_data(data->client, AS73211_REG_CREG3);
802 	if (ret < 0)
803 		return ret;
804 	data->creg3 = ret;
805 	as73211_integration_time_calc_avail(data);
806 
807 	ret = as73211_power(indio_dev, true);
808 	if (ret < 0)
809 		return ret;
810 
811 	ret = devm_add_action_or_reset(dev, as73211_power_disable, indio_dev);
812 	if (ret)
813 		return ret;
814 
815 	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL, as73211_trigger_handler, NULL);
816 	if (ret)
817 		return ret;
818 
819 	if (client->irq) {
820 		ret = devm_request_threaded_irq(&client->dev, client->irq,
821 				NULL,
822 				as73211_ready_handler,
823 				IRQF_ONESHOT,
824 				client->name, indio_dev);
825 		if (ret)
826 			return ret;
827 	}
828 
829 	return devm_iio_device_register(dev, indio_dev);
830 }
831 
832 static int as73211_suspend(struct device *dev)
833 {
834 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
835 
836 	return as73211_power(indio_dev, false);
837 }
838 
839 static int as73211_resume(struct device *dev)
840 {
841 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
842 
843 	return as73211_power(indio_dev, true);
844 }
845 
846 static DEFINE_SIMPLE_DEV_PM_OPS(as73211_pm_ops, as73211_suspend,
847 				as73211_resume);
848 
849 static const struct as73211_spec_dev_data as73211_spec = {
850 	.intensity_scale = as73211_intensity_scale,
851 	.channels = as73211_channels,
852 	.num_channels = ARRAY_SIZE(as73211_channels),
853 };
854 
855 static const struct as73211_spec_dev_data as7331_spec = {
856 	.intensity_scale = as7331_intensity_scale,
857 	.channels = as7331_channels,
858 	.num_channels = ARRAY_SIZE(as7331_channels),
859 };
860 
861 static const struct of_device_id as73211_of_match[] = {
862 	{ .compatible = "ams,as73211", &as73211_spec },
863 	{ .compatible = "ams,as7331", &as7331_spec },
864 	{ }
865 };
866 MODULE_DEVICE_TABLE(of, as73211_of_match);
867 
868 static const struct i2c_device_id as73211_id[] = {
869 	{ "as73211", (kernel_ulong_t)&as73211_spec },
870 	{ "as7331", (kernel_ulong_t)&as7331_spec },
871 	{ }
872 };
873 MODULE_DEVICE_TABLE(i2c, as73211_id);
874 
875 static struct i2c_driver as73211_driver = {
876 	.driver = {
877 		.name           = AS73211_DRV_NAME,
878 		.of_match_table = as73211_of_match,
879 		.pm             = pm_sleep_ptr(&as73211_pm_ops),
880 	},
881 	.probe      = as73211_probe,
882 	.id_table   = as73211_id,
883 };
884 module_i2c_driver(as73211_driver);
885 
886 MODULE_AUTHOR("Christian Eggers <ceggers@arri.de>");
887 MODULE_DESCRIPTION("AS73211 XYZ True Color Sensor driver");
888 MODULE_LICENSE("GPL");
889