xref: /openbmc/linux/drivers/iio/adc/ad7793.c (revision 48cc39c3)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * AD7785/AD7792/AD7793/AD7794/AD7795 SPI ADC driver
4  *
5  * Copyright 2011-2012 Analog Devices Inc.
6  */
7 
8 #include <linux/interrupt.h>
9 #include <linux/device.h>
10 #include <linux/kernel.h>
11 #include <linux/slab.h>
12 #include <linux/sysfs.h>
13 #include <linux/spi/spi.h>
14 #include <linux/regulator/consumer.h>
15 #include <linux/err.h>
16 #include <linux/sched.h>
17 #include <linux/delay.h>
18 #include <linux/module.h>
19 
20 #include <linux/iio/iio.h>
21 #include <linux/iio/sysfs.h>
22 #include <linux/iio/buffer.h>
23 #include <linux/iio/trigger.h>
24 #include <linux/iio/trigger_consumer.h>
25 #include <linux/iio/triggered_buffer.h>
26 #include <linux/iio/adc/ad_sigma_delta.h>
27 #include <linux/platform_data/ad7793.h>
28 
29 /* Registers */
30 #define AD7793_REG_COMM		0 /* Communications Register (WO, 8-bit) */
31 #define AD7793_REG_STAT		0 /* Status Register	     (RO, 8-bit) */
32 #define AD7793_REG_MODE		1 /* Mode Register	     (RW, 16-bit */
33 #define AD7793_REG_CONF		2 /* Configuration Register  (RW, 16-bit) */
34 #define AD7793_REG_DATA		3 /* Data Register	     (RO, 16-/24-bit) */
35 #define AD7793_REG_ID		4 /* ID Register	     (RO, 8-bit) */
36 #define AD7793_REG_IO		5 /* IO Register	     (RO, 8-bit) */
37 #define AD7793_REG_OFFSET	6 /* Offset Register	     (RW, 16-bit
38 				   * (AD7792)/24-bit (AD7793)) */
39 #define AD7793_REG_FULLSALE	7 /* Full-Scale Register
40 				   * (RW, 16-bit (AD7792)/24-bit (AD7793)) */
41 
42 /* Communications Register Bit Designations (AD7793_REG_COMM) */
43 #define AD7793_COMM_WEN		(1 << 7) /* Write Enable */
44 #define AD7793_COMM_WRITE	(0 << 6) /* Write Operation */
45 #define AD7793_COMM_READ	(1 << 6) /* Read Operation */
46 #define AD7793_COMM_ADDR(x)	(((x) & 0x7) << 3) /* Register Address */
47 #define AD7793_COMM_CREAD	(1 << 2) /* Continuous Read of Data Register */
48 
49 /* Status Register Bit Designations (AD7793_REG_STAT) */
50 #define AD7793_STAT_RDY		(1 << 7) /* Ready */
51 #define AD7793_STAT_ERR		(1 << 6) /* Error (Overrange, Underrange) */
52 #define AD7793_STAT_CH3		(1 << 2) /* Channel 3 */
53 #define AD7793_STAT_CH2		(1 << 1) /* Channel 2 */
54 #define AD7793_STAT_CH1		(1 << 0) /* Channel 1 */
55 
56 /* Mode Register Bit Designations (AD7793_REG_MODE) */
57 #define AD7793_MODE_SEL(x)	(((x) & 0x7) << 13) /* Operation Mode Select */
58 #define AD7793_MODE_SEL_MASK	(0x7 << 13) /* Operation Mode Select mask */
59 #define AD7793_MODE_CLKSRC(x)	(((x) & 0x3) << 6) /* ADC Clock Source Select */
60 #define AD7793_MODE_RATE(x)	((x) & 0xF) /* Filter Update Rate Select */
61 
62 #define AD7793_MODE_CONT		0 /* Continuous Conversion Mode */
63 #define AD7793_MODE_SINGLE		1 /* Single Conversion Mode */
64 #define AD7793_MODE_IDLE		2 /* Idle Mode */
65 #define AD7793_MODE_PWRDN		3 /* Power-Down Mode */
66 #define AD7793_MODE_CAL_INT_ZERO	4 /* Internal Zero-Scale Calibration */
67 #define AD7793_MODE_CAL_INT_FULL	5 /* Internal Full-Scale Calibration */
68 #define AD7793_MODE_CAL_SYS_ZERO	6 /* System Zero-Scale Calibration */
69 #define AD7793_MODE_CAL_SYS_FULL	7 /* System Full-Scale Calibration */
70 
71 #define AD7793_CLK_INT		0 /* Internal 64 kHz Clock not
72 				   * available at the CLK pin */
73 #define AD7793_CLK_INT_CO	1 /* Internal 64 kHz Clock available
74 				   * at the CLK pin */
75 #define AD7793_CLK_EXT		2 /* External 64 kHz Clock */
76 #define AD7793_CLK_EXT_DIV2	3 /* External Clock divided by 2 */
77 
78 /* Configuration Register Bit Designations (AD7793_REG_CONF) */
79 #define AD7793_CONF_VBIAS(x)	(((x) & 0x3) << 14) /* Bias Voltage
80 						     * Generator Enable */
81 #define AD7793_CONF_BO_EN	(1 << 13) /* Burnout Current Enable */
82 #define AD7793_CONF_UNIPOLAR	(1 << 12) /* Unipolar/Bipolar Enable */
83 #define AD7793_CONF_BOOST	(1 << 11) /* Boost Enable */
84 #define AD7793_CONF_GAIN(x)	(((x) & 0x7) << 8) /* Gain Select */
85 #define AD7793_CONF_REFSEL(x)	((x) << 6) /* INT/EXT Reference Select */
86 #define AD7793_CONF_BUF		(1 << 4) /* Buffered Mode Enable */
87 #define AD7793_CONF_CHAN(x)	((x) & 0xf) /* Channel select */
88 #define AD7793_CONF_CHAN_MASK	0xf /* Channel select mask */
89 
90 #define AD7793_CH_AIN1P_AIN1M	0 /* AIN1(+) - AIN1(-) */
91 #define AD7793_CH_AIN2P_AIN2M	1 /* AIN2(+) - AIN2(-) */
92 #define AD7793_CH_AIN3P_AIN3M	2 /* AIN3(+) - AIN3(-) */
93 #define AD7793_CH_AIN1M_AIN1M	3 /* AIN1(-) - AIN1(-) */
94 #define AD7793_CH_TEMP		6 /* Temp Sensor */
95 #define AD7793_CH_AVDD_MONITOR	7 /* AVDD Monitor */
96 
97 #define AD7795_CH_AIN4P_AIN4M	4 /* AIN4(+) - AIN4(-) */
98 #define AD7795_CH_AIN5P_AIN5M	5 /* AIN5(+) - AIN5(-) */
99 #define AD7795_CH_AIN6P_AIN6M	6 /* AIN6(+) - AIN6(-) */
100 #define AD7795_CH_AIN1M_AIN1M	8 /* AIN1(-) - AIN1(-) */
101 
102 /* ID Register Bit Designations (AD7793_REG_ID) */
103 #define AD7785_ID		0x3
104 #define AD7792_ID		0xA
105 #define AD7793_ID		0xB
106 #define AD7794_ID		0xF
107 #define AD7795_ID		0xF
108 #define AD7796_ID		0xA
109 #define AD7797_ID		0xB
110 #define AD7798_ID		0x8
111 #define AD7799_ID		0x9
112 #define AD7793_ID_MASK		0xF
113 
114 /* IO (Excitation Current Sources) Register Bit Designations (AD7793_REG_IO) */
115 #define AD7793_IO_IEXC1_IOUT1_IEXC2_IOUT2	0 /* IEXC1 connect to IOUT1,
116 						   * IEXC2 connect to IOUT2 */
117 #define AD7793_IO_IEXC1_IOUT2_IEXC2_IOUT1	1 /* IEXC1 connect to IOUT2,
118 						   * IEXC2 connect to IOUT1 */
119 #define AD7793_IO_IEXC1_IEXC2_IOUT1		2 /* Both current sources
120 						   * IEXC1,2 connect to IOUT1 */
121 #define AD7793_IO_IEXC1_IEXC2_IOUT2		3 /* Both current sources
122 						   * IEXC1,2 connect to IOUT2 */
123 
124 #define AD7793_IO_IXCEN_10uA	(1 << 0) /* Excitation Current 10uA */
125 #define AD7793_IO_IXCEN_210uA	(2 << 0) /* Excitation Current 210uA */
126 #define AD7793_IO_IXCEN_1mA	(3 << 0) /* Excitation Current 1mA */
127 
128 /* NOTE:
129  * The AD7792/AD7793 features a dual use data out ready DOUT/RDY output.
130  * In order to avoid contentions on the SPI bus, it's therefore necessary
131  * to use spi bus locking.
132  *
133  * The DOUT/RDY output must also be wired to an interrupt capable GPIO.
134  */
135 
136 #define AD7793_FLAG_HAS_CLKSEL		BIT(0)
137 #define AD7793_FLAG_HAS_REFSEL		BIT(1)
138 #define AD7793_FLAG_HAS_VBIAS		BIT(2)
139 #define AD7793_HAS_EXITATION_CURRENT	BIT(3)
140 #define AD7793_FLAG_HAS_GAIN		BIT(4)
141 #define AD7793_FLAG_HAS_BUFFER		BIT(5)
142 
143 struct ad7793_chip_info {
144 	unsigned int id;
145 	const struct iio_chan_spec *channels;
146 	unsigned int num_channels;
147 	unsigned int flags;
148 
149 	const struct iio_info *iio_info;
150 	const u16 *sample_freq_avail;
151 };
152 
153 struct ad7793_state {
154 	const struct ad7793_chip_info	*chip_info;
155 	struct regulator		*reg;
156 	u16				int_vref_mv;
157 	u16				mode;
158 	u16				conf;
159 	u32				scale_avail[8][2];
160 
161 	struct ad_sigma_delta		sd;
162 
163 };
164 
165 enum ad7793_supported_device_ids {
166 	ID_AD7785,
167 	ID_AD7792,
168 	ID_AD7793,
169 	ID_AD7794,
170 	ID_AD7795,
171 	ID_AD7796,
172 	ID_AD7797,
173 	ID_AD7798,
174 	ID_AD7799,
175 };
176 
177 static struct ad7793_state *ad_sigma_delta_to_ad7793(struct ad_sigma_delta *sd)
178 {
179 	return container_of(sd, struct ad7793_state, sd);
180 }
181 
182 static int ad7793_set_channel(struct ad_sigma_delta *sd, unsigned int channel)
183 {
184 	struct ad7793_state *st = ad_sigma_delta_to_ad7793(sd);
185 
186 	st->conf &= ~AD7793_CONF_CHAN_MASK;
187 	st->conf |= AD7793_CONF_CHAN(channel);
188 
189 	return ad_sd_write_reg(&st->sd, AD7793_REG_CONF, 2, st->conf);
190 }
191 
192 static int ad7793_set_mode(struct ad_sigma_delta *sd,
193 			   enum ad_sigma_delta_mode mode)
194 {
195 	struct ad7793_state *st = ad_sigma_delta_to_ad7793(sd);
196 
197 	st->mode &= ~AD7793_MODE_SEL_MASK;
198 	st->mode |= AD7793_MODE_SEL(mode);
199 
200 	return ad_sd_write_reg(&st->sd, AD7793_REG_MODE, 2, st->mode);
201 }
202 
203 static const struct ad_sigma_delta_info ad7793_sigma_delta_info = {
204 	.set_channel = ad7793_set_channel,
205 	.set_mode = ad7793_set_mode,
206 	.has_registers = true,
207 	.addr_shift = 3,
208 	.read_mask = BIT(6),
209 	.irq_flags = IRQF_TRIGGER_LOW,
210 };
211 
212 static const struct ad_sd_calib_data ad7793_calib_arr[6] = {
213 	{AD7793_MODE_CAL_INT_ZERO, AD7793_CH_AIN1P_AIN1M},
214 	{AD7793_MODE_CAL_INT_FULL, AD7793_CH_AIN1P_AIN1M},
215 	{AD7793_MODE_CAL_INT_ZERO, AD7793_CH_AIN2P_AIN2M},
216 	{AD7793_MODE_CAL_INT_FULL, AD7793_CH_AIN2P_AIN2M},
217 	{AD7793_MODE_CAL_INT_ZERO, AD7793_CH_AIN3P_AIN3M},
218 	{AD7793_MODE_CAL_INT_FULL, AD7793_CH_AIN3P_AIN3M}
219 };
220 
221 static int ad7793_calibrate_all(struct ad7793_state *st)
222 {
223 	return ad_sd_calibrate_all(&st->sd, ad7793_calib_arr,
224 				   ARRAY_SIZE(ad7793_calib_arr));
225 }
226 
227 static int ad7793_check_platform_data(struct ad7793_state *st,
228 	const struct ad7793_platform_data *pdata)
229 {
230 	if ((pdata->current_source_direction == AD7793_IEXEC1_IEXEC2_IOUT1 ||
231 		pdata->current_source_direction == AD7793_IEXEC1_IEXEC2_IOUT2) &&
232 		((pdata->exitation_current != AD7793_IX_10uA) &&
233 		(pdata->exitation_current != AD7793_IX_210uA)))
234 		return -EINVAL;
235 
236 	if (!(st->chip_info->flags & AD7793_FLAG_HAS_CLKSEL) &&
237 		pdata->clock_src != AD7793_CLK_SRC_INT)
238 		return -EINVAL;
239 
240 	if (!(st->chip_info->flags & AD7793_FLAG_HAS_REFSEL) &&
241 		pdata->refsel != AD7793_REFSEL_REFIN1)
242 		return -EINVAL;
243 
244 	if (!(st->chip_info->flags & AD7793_FLAG_HAS_VBIAS) &&
245 		pdata->bias_voltage != AD7793_BIAS_VOLTAGE_DISABLED)
246 		return -EINVAL;
247 
248 	if (!(st->chip_info->flags & AD7793_HAS_EXITATION_CURRENT) &&
249 		pdata->exitation_current != AD7793_IX_DISABLED)
250 		return -EINVAL;
251 
252 	return 0;
253 }
254 
255 static int ad7793_setup(struct iio_dev *indio_dev,
256 	const struct ad7793_platform_data *pdata,
257 	unsigned int vref_mv)
258 {
259 	struct ad7793_state *st = iio_priv(indio_dev);
260 	int i, ret;
261 	unsigned long long scale_uv;
262 	u32 id;
263 
264 	ret = ad7793_check_platform_data(st, pdata);
265 	if (ret)
266 		return ret;
267 
268 	/* reset the serial interface */
269 	ret = ad_sd_reset(&st->sd, 32);
270 	if (ret < 0)
271 		goto out;
272 	usleep_range(500, 2000); /* Wait for at least 500us */
273 
274 	/* write/read test for device presence */
275 	ret = ad_sd_read_reg(&st->sd, AD7793_REG_ID, 1, &id);
276 	if (ret)
277 		goto out;
278 
279 	id &= AD7793_ID_MASK;
280 
281 	if (id != st->chip_info->id) {
282 		ret = -ENODEV;
283 		dev_err(&st->sd.spi->dev, "device ID query failed\n");
284 		goto out;
285 	}
286 
287 	st->mode = AD7793_MODE_RATE(1);
288 	st->conf = 0;
289 
290 	if (st->chip_info->flags & AD7793_FLAG_HAS_CLKSEL)
291 		st->mode |= AD7793_MODE_CLKSRC(pdata->clock_src);
292 	if (st->chip_info->flags & AD7793_FLAG_HAS_REFSEL)
293 		st->conf |= AD7793_CONF_REFSEL(pdata->refsel);
294 	if (st->chip_info->flags & AD7793_FLAG_HAS_VBIAS)
295 		st->conf |= AD7793_CONF_VBIAS(pdata->bias_voltage);
296 	if (pdata->buffered || !(st->chip_info->flags & AD7793_FLAG_HAS_BUFFER))
297 		st->conf |= AD7793_CONF_BUF;
298 	if (pdata->boost_enable &&
299 		(st->chip_info->flags & AD7793_FLAG_HAS_VBIAS))
300 		st->conf |= AD7793_CONF_BOOST;
301 	if (pdata->burnout_current)
302 		st->conf |= AD7793_CONF_BO_EN;
303 	if (pdata->unipolar)
304 		st->conf |= AD7793_CONF_UNIPOLAR;
305 
306 	if (!(st->chip_info->flags & AD7793_FLAG_HAS_GAIN))
307 		st->conf |= AD7793_CONF_GAIN(7);
308 
309 	ret = ad7793_set_mode(&st->sd, AD_SD_MODE_IDLE);
310 	if (ret)
311 		goto out;
312 
313 	ret = ad7793_set_channel(&st->sd, 0);
314 	if (ret)
315 		goto out;
316 
317 	if (st->chip_info->flags & AD7793_HAS_EXITATION_CURRENT) {
318 		ret = ad_sd_write_reg(&st->sd, AD7793_REG_IO, 1,
319 				pdata->exitation_current |
320 				(pdata->current_source_direction << 2));
321 		if (ret)
322 			goto out;
323 	}
324 
325 	ret = ad7793_calibrate_all(st);
326 	if (ret)
327 		goto out;
328 
329 	/* Populate available ADC input ranges */
330 	for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++) {
331 		scale_uv = ((u64)vref_mv * 100000000)
332 			>> (st->chip_info->channels[0].scan_type.realbits -
333 			(!!(st->conf & AD7793_CONF_UNIPOLAR) ? 0 : 1));
334 		scale_uv >>= i;
335 
336 		st->scale_avail[i][1] = do_div(scale_uv, 100000000) * 10;
337 		st->scale_avail[i][0] = scale_uv;
338 	}
339 
340 	return 0;
341 out:
342 	dev_err(&st->sd.spi->dev, "setup failed\n");
343 	return ret;
344 }
345 
346 static const u16 ad7793_sample_freq_avail[16] = {0, 470, 242, 123, 62, 50, 39,
347 					33, 19, 17, 16, 12, 10, 8, 6, 4};
348 
349 static const u16 ad7797_sample_freq_avail[16] = {0, 0, 0, 123, 62, 50, 0,
350 					33, 0, 17, 16, 12, 10, 8, 6, 4};
351 
352 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(
353 	"470 242 123 62 50 39 33 19 17 16 12 10 8 6 4");
354 
355 static IIO_CONST_ATTR_NAMED(sampling_frequency_available_ad7797,
356 	sampling_frequency_available, "123 62 50 33 17 16 12 10 8 6 4");
357 
358 static int ad7793_read_avail(struct iio_dev *indio_dev,
359 			     struct iio_chan_spec const *chan,
360 			     const int **vals, int *type, int *length,
361 			     long mask)
362 {
363 	struct ad7793_state *st = iio_priv(indio_dev);
364 
365 	switch (mask) {
366 	case IIO_CHAN_INFO_SCALE:
367 		*vals = (int *)st->scale_avail;
368 		*type = IIO_VAL_INT_PLUS_NANO;
369 		/* Values are stored in a 2D matrix  */
370 		*length = ARRAY_SIZE(st->scale_avail) * 2;
371 
372 		return IIO_AVAIL_LIST;
373 	default:
374 		return -EINVAL;
375 	}
376 }
377 
378 static struct attribute *ad7793_attributes[] = {
379 	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
380 	NULL
381 };
382 
383 static const struct attribute_group ad7793_attribute_group = {
384 	.attrs = ad7793_attributes,
385 };
386 
387 static struct attribute *ad7797_attributes[] = {
388 	&iio_const_attr_sampling_frequency_available_ad7797.dev_attr.attr,
389 	NULL
390 };
391 
392 static const struct attribute_group ad7797_attribute_group = {
393 	.attrs = ad7797_attributes,
394 };
395 
396 static int ad7793_read_raw(struct iio_dev *indio_dev,
397 			   struct iio_chan_spec const *chan,
398 			   int *val,
399 			   int *val2,
400 			   long m)
401 {
402 	struct ad7793_state *st = iio_priv(indio_dev);
403 	int ret;
404 	unsigned long long scale_uv;
405 	bool unipolar = !!(st->conf & AD7793_CONF_UNIPOLAR);
406 
407 	switch (m) {
408 	case IIO_CHAN_INFO_RAW:
409 		ret = ad_sigma_delta_single_conversion(indio_dev, chan, val);
410 		if (ret < 0)
411 			return ret;
412 
413 		return IIO_VAL_INT;
414 
415 	case IIO_CHAN_INFO_SCALE:
416 		switch (chan->type) {
417 		case IIO_VOLTAGE:
418 			if (chan->differential) {
419 				*val = st->
420 					scale_avail[(st->conf >> 8) & 0x7][0];
421 				*val2 = st->
422 					scale_avail[(st->conf >> 8) & 0x7][1];
423 				return IIO_VAL_INT_PLUS_NANO;
424 			}
425 			/* 1170mV / 2^23 * 6 */
426 			scale_uv = (1170ULL * 1000000000ULL * 6ULL);
427 			break;
428 		case IIO_TEMP:
429 				/* 1170mV / 0.81 mV/C / 2^23 */
430 				scale_uv = 1444444444444444ULL;
431 			break;
432 		default:
433 			return -EINVAL;
434 		}
435 
436 		scale_uv >>= (chan->scan_type.realbits - (unipolar ? 0 : 1));
437 		*val = 0;
438 		*val2 = scale_uv;
439 		return IIO_VAL_INT_PLUS_NANO;
440 	case IIO_CHAN_INFO_OFFSET:
441 		if (!unipolar)
442 			*val = -(1 << (chan->scan_type.realbits - 1));
443 		else
444 			*val = 0;
445 
446 		/* Kelvin to Celsius */
447 		if (chan->type == IIO_TEMP) {
448 			unsigned long long offset;
449 			unsigned int shift;
450 
451 			shift = chan->scan_type.realbits - (unipolar ? 0 : 1);
452 			offset = 273ULL << shift;
453 			do_div(offset, 1444);
454 			*val -= offset;
455 		}
456 		return IIO_VAL_INT;
457 	case IIO_CHAN_INFO_SAMP_FREQ:
458 		*val = st->chip_info
459 			       ->sample_freq_avail[AD7793_MODE_RATE(st->mode)];
460 		return IIO_VAL_INT;
461 	}
462 	return -EINVAL;
463 }
464 
465 static int ad7793_write_raw(struct iio_dev *indio_dev,
466 			       struct iio_chan_spec const *chan,
467 			       int val,
468 			       int val2,
469 			       long mask)
470 {
471 	struct ad7793_state *st = iio_priv(indio_dev);
472 	int ret, i;
473 	unsigned int tmp;
474 
475 	ret = iio_device_claim_direct_mode(indio_dev);
476 	if (ret)
477 		return ret;
478 
479 	switch (mask) {
480 	case IIO_CHAN_INFO_SCALE:
481 		ret = -EINVAL;
482 		for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++)
483 			if (val2 == st->scale_avail[i][1]) {
484 				ret = 0;
485 				tmp = st->conf;
486 				st->conf &= ~AD7793_CONF_GAIN(-1);
487 				st->conf |= AD7793_CONF_GAIN(i);
488 
489 				if (tmp == st->conf)
490 					break;
491 
492 				ad_sd_write_reg(&st->sd, AD7793_REG_CONF,
493 						sizeof(st->conf), st->conf);
494 				ad7793_calibrate_all(st);
495 				break;
496 			}
497 		break;
498 	case IIO_CHAN_INFO_SAMP_FREQ:
499 		if (!val) {
500 			ret = -EINVAL;
501 			break;
502 		}
503 
504 		for (i = 0; i < 16; i++)
505 			if (val == st->chip_info->sample_freq_avail[i])
506 				break;
507 
508 		if (i == 16) {
509 			ret = -EINVAL;
510 			break;
511 		}
512 
513 		st->mode &= ~AD7793_MODE_RATE(-1);
514 		st->mode |= AD7793_MODE_RATE(i);
515 		ad_sd_write_reg(&st->sd, AD7793_REG_MODE, sizeof(st->mode),
516 				st->mode);
517 		break;
518 	default:
519 		ret = -EINVAL;
520 	}
521 
522 	iio_device_release_direct_mode(indio_dev);
523 	return ret;
524 }
525 
526 static int ad7793_write_raw_get_fmt(struct iio_dev *indio_dev,
527 			       struct iio_chan_spec const *chan,
528 			       long mask)
529 {
530 	return IIO_VAL_INT_PLUS_NANO;
531 }
532 
533 static const struct iio_info ad7793_info = {
534 	.read_raw = &ad7793_read_raw,
535 	.write_raw = &ad7793_write_raw,
536 	.write_raw_get_fmt = &ad7793_write_raw_get_fmt,
537 	.read_avail = ad7793_read_avail,
538 	.attrs = &ad7793_attribute_group,
539 	.validate_trigger = ad_sd_validate_trigger,
540 };
541 
542 static const struct iio_info ad7797_info = {
543 	.read_raw = &ad7793_read_raw,
544 	.write_raw = &ad7793_write_raw,
545 	.write_raw_get_fmt = &ad7793_write_raw_get_fmt,
546 	.attrs = &ad7797_attribute_group,
547 	.validate_trigger = ad_sd_validate_trigger,
548 };
549 
550 #define __AD7793_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
551 	_storagebits, _shift, _extend_name, _type, _mask_type_av, _mask_all) \
552 	{ \
553 		.type = (_type), \
554 		.differential = (_channel2 == -1 ? 0 : 1), \
555 		.indexed = 1, \
556 		.channel = (_channel1), \
557 		.channel2 = (_channel2), \
558 		.address = (_address), \
559 		.extend_name = (_extend_name), \
560 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
561 			BIT(IIO_CHAN_INFO_OFFSET), \
562 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
563 		.info_mask_shared_by_type_available = (_mask_type_av), \
564 		.info_mask_shared_by_all = _mask_all, \
565 		.scan_index = (_si), \
566 		.scan_type = { \
567 			.sign = 'u', \
568 			.realbits = (_bits), \
569 			.storagebits = (_storagebits), \
570 			.shift = (_shift), \
571 			.endianness = IIO_BE, \
572 		}, \
573 	}
574 
575 #define AD7793_DIFF_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
576 	_storagebits, _shift) \
577 	__AD7793_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
578 		_storagebits, _shift, NULL, IIO_VOLTAGE, \
579 		BIT(IIO_CHAN_INFO_SCALE), \
580 		BIT(IIO_CHAN_INFO_SAMP_FREQ))
581 
582 #define AD7793_SHORTED_CHANNEL(_si, _channel, _address, _bits, \
583 	_storagebits, _shift) \
584 	__AD7793_CHANNEL(_si, _channel, _channel, _address, _bits, \
585 		_storagebits, _shift, "shorted", IIO_VOLTAGE, \
586 		BIT(IIO_CHAN_INFO_SCALE), \
587 		BIT(IIO_CHAN_INFO_SAMP_FREQ))
588 
589 #define AD7793_TEMP_CHANNEL(_si, _address, _bits, _storagebits, _shift) \
590 	__AD7793_CHANNEL(_si, 0, -1, _address, _bits, \
591 		_storagebits, _shift, NULL, IIO_TEMP, \
592 		0, \
593 		BIT(IIO_CHAN_INFO_SAMP_FREQ))
594 
595 #define AD7793_SUPPLY_CHANNEL(_si, _channel, _address, _bits, _storagebits, \
596 	_shift) \
597 	__AD7793_CHANNEL(_si, _channel, -1, _address, _bits, \
598 		_storagebits, _shift, "supply", IIO_VOLTAGE, \
599 		0, \
600 		BIT(IIO_CHAN_INFO_SAMP_FREQ))
601 
602 #define AD7797_DIFF_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
603 	_storagebits, _shift) \
604 	__AD7793_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
605 		_storagebits, _shift, NULL, IIO_VOLTAGE, \
606 		0, \
607 		BIT(IIO_CHAN_INFO_SAMP_FREQ))
608 
609 #define AD7797_SHORTED_CHANNEL(_si, _channel, _address, _bits, \
610 	_storagebits, _shift) \
611 	__AD7793_CHANNEL(_si, _channel, _channel, _address, _bits, \
612 		_storagebits, _shift, "shorted", IIO_VOLTAGE, \
613 		0, \
614 		BIT(IIO_CHAN_INFO_SAMP_FREQ))
615 
616 #define DECLARE_AD7793_CHANNELS(_name, _b, _sb, _s) \
617 const struct iio_chan_spec _name##_channels[] = { \
618 	AD7793_DIFF_CHANNEL(0, 0, 0, AD7793_CH_AIN1P_AIN1M, (_b), (_sb), (_s)), \
619 	AD7793_DIFF_CHANNEL(1, 1, 1, AD7793_CH_AIN2P_AIN2M, (_b), (_sb), (_s)), \
620 	AD7793_DIFF_CHANNEL(2, 2, 2, AD7793_CH_AIN3P_AIN3M, (_b), (_sb), (_s)), \
621 	AD7793_SHORTED_CHANNEL(3, 0, AD7793_CH_AIN1M_AIN1M, (_b), (_sb), (_s)), \
622 	AD7793_TEMP_CHANNEL(4, AD7793_CH_TEMP, (_b), (_sb), (_s)), \
623 	AD7793_SUPPLY_CHANNEL(5, 3, AD7793_CH_AVDD_MONITOR, (_b), (_sb), (_s)), \
624 	IIO_CHAN_SOFT_TIMESTAMP(6), \
625 }
626 
627 #define DECLARE_AD7795_CHANNELS(_name, _b, _sb) \
628 const struct iio_chan_spec _name##_channels[] = { \
629 	AD7793_DIFF_CHANNEL(0, 0, 0, AD7793_CH_AIN1P_AIN1M, (_b), (_sb), 0), \
630 	AD7793_DIFF_CHANNEL(1, 1, 1, AD7793_CH_AIN2P_AIN2M, (_b), (_sb), 0), \
631 	AD7793_DIFF_CHANNEL(2, 2, 2, AD7793_CH_AIN3P_AIN3M, (_b), (_sb), 0), \
632 	AD7793_DIFF_CHANNEL(3, 3, 3, AD7795_CH_AIN4P_AIN4M, (_b), (_sb), 0), \
633 	AD7793_DIFF_CHANNEL(4, 4, 4, AD7795_CH_AIN5P_AIN5M, (_b), (_sb), 0), \
634 	AD7793_DIFF_CHANNEL(5, 5, 5, AD7795_CH_AIN6P_AIN6M, (_b), (_sb), 0), \
635 	AD7793_SHORTED_CHANNEL(6, 0, AD7795_CH_AIN1M_AIN1M, (_b), (_sb), 0), \
636 	AD7793_TEMP_CHANNEL(7, AD7793_CH_TEMP, (_b), (_sb), 0), \
637 	AD7793_SUPPLY_CHANNEL(8, 3, AD7793_CH_AVDD_MONITOR, (_b), (_sb), 0), \
638 	IIO_CHAN_SOFT_TIMESTAMP(9), \
639 }
640 
641 #define DECLARE_AD7797_CHANNELS(_name, _b, _sb) \
642 const struct iio_chan_spec _name##_channels[] = { \
643 	AD7797_DIFF_CHANNEL(0, 0, 0, AD7793_CH_AIN1P_AIN1M, (_b), (_sb), 0), \
644 	AD7797_SHORTED_CHANNEL(1, 0, AD7793_CH_AIN1M_AIN1M, (_b), (_sb), 0), \
645 	AD7793_TEMP_CHANNEL(2, AD7793_CH_TEMP, (_b), (_sb), 0), \
646 	AD7793_SUPPLY_CHANNEL(3, 3, AD7793_CH_AVDD_MONITOR, (_b), (_sb), 0), \
647 	IIO_CHAN_SOFT_TIMESTAMP(4), \
648 }
649 
650 #define DECLARE_AD7799_CHANNELS(_name, _b, _sb) \
651 const struct iio_chan_spec _name##_channels[] = { \
652 	AD7793_DIFF_CHANNEL(0, 0, 0, AD7793_CH_AIN1P_AIN1M, (_b), (_sb), 0), \
653 	AD7793_DIFF_CHANNEL(1, 1, 1, AD7793_CH_AIN2P_AIN2M, (_b), (_sb), 0), \
654 	AD7793_DIFF_CHANNEL(2, 2, 2, AD7793_CH_AIN3P_AIN3M, (_b), (_sb), 0), \
655 	AD7793_SHORTED_CHANNEL(3, 0, AD7793_CH_AIN1M_AIN1M, (_b), (_sb), 0), \
656 	AD7793_SUPPLY_CHANNEL(4, 3, AD7793_CH_AVDD_MONITOR, (_b), (_sb), 0), \
657 	IIO_CHAN_SOFT_TIMESTAMP(5), \
658 }
659 
660 static DECLARE_AD7793_CHANNELS(ad7785, 20, 32, 4);
661 static DECLARE_AD7793_CHANNELS(ad7792, 16, 32, 0);
662 static DECLARE_AD7793_CHANNELS(ad7793, 24, 32, 0);
663 static DECLARE_AD7795_CHANNELS(ad7794, 16, 32);
664 static DECLARE_AD7795_CHANNELS(ad7795, 24, 32);
665 static DECLARE_AD7797_CHANNELS(ad7796, 16, 16);
666 static DECLARE_AD7797_CHANNELS(ad7797, 24, 32);
667 static DECLARE_AD7799_CHANNELS(ad7798, 16, 16);
668 static DECLARE_AD7799_CHANNELS(ad7799, 24, 32);
669 
670 static const struct ad7793_chip_info ad7793_chip_info_tbl[] = {
671 	[ID_AD7785] = {
672 		.id = AD7785_ID,
673 		.channels = ad7785_channels,
674 		.num_channels = ARRAY_SIZE(ad7785_channels),
675 		.iio_info = &ad7793_info,
676 		.sample_freq_avail = ad7793_sample_freq_avail,
677 		.flags = AD7793_FLAG_HAS_CLKSEL |
678 			AD7793_FLAG_HAS_REFSEL |
679 			AD7793_FLAG_HAS_VBIAS |
680 			AD7793_HAS_EXITATION_CURRENT |
681 			AD7793_FLAG_HAS_GAIN |
682 			AD7793_FLAG_HAS_BUFFER,
683 	},
684 	[ID_AD7792] = {
685 		.id = AD7792_ID,
686 		.channels = ad7792_channels,
687 		.num_channels = ARRAY_SIZE(ad7792_channels),
688 		.iio_info = &ad7793_info,
689 		.sample_freq_avail = ad7793_sample_freq_avail,
690 		.flags = AD7793_FLAG_HAS_CLKSEL |
691 			AD7793_FLAG_HAS_REFSEL |
692 			AD7793_FLAG_HAS_VBIAS |
693 			AD7793_HAS_EXITATION_CURRENT |
694 			AD7793_FLAG_HAS_GAIN |
695 			AD7793_FLAG_HAS_BUFFER,
696 	},
697 	[ID_AD7793] = {
698 		.id = AD7793_ID,
699 		.channels = ad7793_channels,
700 		.num_channels = ARRAY_SIZE(ad7793_channels),
701 		.iio_info = &ad7793_info,
702 		.sample_freq_avail = ad7793_sample_freq_avail,
703 		.flags = AD7793_FLAG_HAS_CLKSEL |
704 			AD7793_FLAG_HAS_REFSEL |
705 			AD7793_FLAG_HAS_VBIAS |
706 			AD7793_HAS_EXITATION_CURRENT |
707 			AD7793_FLAG_HAS_GAIN |
708 			AD7793_FLAG_HAS_BUFFER,
709 	},
710 	[ID_AD7794] = {
711 		.id = AD7794_ID,
712 		.channels = ad7794_channels,
713 		.num_channels = ARRAY_SIZE(ad7794_channels),
714 		.iio_info = &ad7793_info,
715 		.sample_freq_avail = ad7793_sample_freq_avail,
716 		.flags = AD7793_FLAG_HAS_CLKSEL |
717 			AD7793_FLAG_HAS_REFSEL |
718 			AD7793_FLAG_HAS_VBIAS |
719 			AD7793_HAS_EXITATION_CURRENT |
720 			AD7793_FLAG_HAS_GAIN |
721 			AD7793_FLAG_HAS_BUFFER,
722 	},
723 	[ID_AD7795] = {
724 		.id = AD7795_ID,
725 		.channels = ad7795_channels,
726 		.num_channels = ARRAY_SIZE(ad7795_channels),
727 		.iio_info = &ad7793_info,
728 		.sample_freq_avail = ad7793_sample_freq_avail,
729 		.flags = AD7793_FLAG_HAS_CLKSEL |
730 			AD7793_FLAG_HAS_REFSEL |
731 			AD7793_FLAG_HAS_VBIAS |
732 			AD7793_HAS_EXITATION_CURRENT |
733 			AD7793_FLAG_HAS_GAIN |
734 			AD7793_FLAG_HAS_BUFFER,
735 	},
736 	[ID_AD7796] = {
737 		.id = AD7796_ID,
738 		.channels = ad7796_channels,
739 		.num_channels = ARRAY_SIZE(ad7796_channels),
740 		.iio_info = &ad7797_info,
741 		.sample_freq_avail = ad7797_sample_freq_avail,
742 		.flags = AD7793_FLAG_HAS_CLKSEL,
743 	},
744 	[ID_AD7797] = {
745 		.id = AD7797_ID,
746 		.channels = ad7797_channels,
747 		.num_channels = ARRAY_SIZE(ad7797_channels),
748 		.iio_info = &ad7797_info,
749 		.sample_freq_avail = ad7797_sample_freq_avail,
750 		.flags = AD7793_FLAG_HAS_CLKSEL,
751 	},
752 	[ID_AD7798] = {
753 		.id = AD7798_ID,
754 		.channels = ad7798_channels,
755 		.num_channels = ARRAY_SIZE(ad7798_channels),
756 		.iio_info = &ad7793_info,
757 		.sample_freq_avail = ad7793_sample_freq_avail,
758 		.flags = AD7793_FLAG_HAS_GAIN |
759 			AD7793_FLAG_HAS_BUFFER,
760 	},
761 	[ID_AD7799] = {
762 		.id = AD7799_ID,
763 		.channels = ad7799_channels,
764 		.num_channels = ARRAY_SIZE(ad7799_channels),
765 		.iio_info = &ad7793_info,
766 		.sample_freq_avail = ad7793_sample_freq_avail,
767 		.flags = AD7793_FLAG_HAS_GAIN |
768 			AD7793_FLAG_HAS_BUFFER,
769 	},
770 };
771 
772 static void ad7793_reg_disable(void *reg)
773 {
774 	regulator_disable(reg);
775 }
776 
777 static int ad7793_probe(struct spi_device *spi)
778 {
779 	const struct ad7793_platform_data *pdata = spi->dev.platform_data;
780 	struct ad7793_state *st;
781 	struct iio_dev *indio_dev;
782 	int ret, vref_mv = 0;
783 
784 	if (!pdata) {
785 		dev_err(&spi->dev, "no platform data?\n");
786 		return -ENODEV;
787 	}
788 
789 	if (!spi->irq) {
790 		dev_err(&spi->dev, "no IRQ?\n");
791 		return -ENODEV;
792 	}
793 
794 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
795 	if (indio_dev == NULL)
796 		return -ENOMEM;
797 
798 	st = iio_priv(indio_dev);
799 
800 	ad_sd_init(&st->sd, indio_dev, spi, &ad7793_sigma_delta_info);
801 
802 	if (pdata->refsel != AD7793_REFSEL_INTERNAL) {
803 		st->reg = devm_regulator_get(&spi->dev, "refin");
804 		if (IS_ERR(st->reg))
805 			return PTR_ERR(st->reg);
806 
807 		ret = regulator_enable(st->reg);
808 		if (ret)
809 			return ret;
810 
811 		ret = devm_add_action_or_reset(&spi->dev, ad7793_reg_disable, st->reg);
812 		if (ret)
813 			return ret;
814 
815 		vref_mv = regulator_get_voltage(st->reg);
816 		if (vref_mv < 0)
817 			return vref_mv;
818 
819 		vref_mv /= 1000;
820 	} else {
821 		vref_mv = 1170; /* Build-in ref */
822 	}
823 
824 	st->chip_info =
825 		&ad7793_chip_info_tbl[spi_get_device_id(spi)->driver_data];
826 
827 	indio_dev->name = spi_get_device_id(spi)->name;
828 	indio_dev->modes = INDIO_DIRECT_MODE;
829 	indio_dev->channels = st->chip_info->channels;
830 	indio_dev->num_channels = st->chip_info->num_channels;
831 	indio_dev->info = st->chip_info->iio_info;
832 
833 	ret = devm_ad_sd_setup_buffer_and_trigger(&spi->dev, indio_dev);
834 	if (ret)
835 		return ret;
836 
837 	ret = ad7793_setup(indio_dev, pdata, vref_mv);
838 	if (ret)
839 		return ret;
840 
841 	return devm_iio_device_register(&spi->dev, indio_dev);
842 }
843 
844 static const struct spi_device_id ad7793_id[] = {
845 	{"ad7785", ID_AD7785},
846 	{"ad7792", ID_AD7792},
847 	{"ad7793", ID_AD7793},
848 	{"ad7794", ID_AD7794},
849 	{"ad7795", ID_AD7795},
850 	{"ad7796", ID_AD7796},
851 	{"ad7797", ID_AD7797},
852 	{"ad7798", ID_AD7798},
853 	{"ad7799", ID_AD7799},
854 	{}
855 };
856 MODULE_DEVICE_TABLE(spi, ad7793_id);
857 
858 static struct spi_driver ad7793_driver = {
859 	.driver = {
860 		.name	= "ad7793",
861 	},
862 	.probe		= ad7793_probe,
863 	.id_table	= ad7793_id,
864 };
865 module_spi_driver(ad7793_driver);
866 
867 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
868 MODULE_DESCRIPTION("Analog Devices AD7793 and similar ADCs");
869 MODULE_LICENSE("GPL v2");
870