xref: /openbmc/linux/drivers/iio/adc/ad7793.c (revision 27ab1c1c)
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 		dev_err(&st->sd.spi->dev, "device ID query failed\n");
283 		goto out;
284 	}
285 
286 	st->mode = AD7793_MODE_RATE(1);
287 	st->conf = 0;
288 
289 	if (st->chip_info->flags & AD7793_FLAG_HAS_CLKSEL)
290 		st->mode |= AD7793_MODE_CLKSRC(pdata->clock_src);
291 	if (st->chip_info->flags & AD7793_FLAG_HAS_REFSEL)
292 		st->conf |= AD7793_CONF_REFSEL(pdata->refsel);
293 	if (st->chip_info->flags & AD7793_FLAG_HAS_VBIAS)
294 		st->conf |= AD7793_CONF_VBIAS(pdata->bias_voltage);
295 	if (pdata->buffered || !(st->chip_info->flags & AD7793_FLAG_HAS_BUFFER))
296 		st->conf |= AD7793_CONF_BUF;
297 	if (pdata->boost_enable &&
298 		(st->chip_info->flags & AD7793_FLAG_HAS_VBIAS))
299 		st->conf |= AD7793_CONF_BOOST;
300 	if (pdata->burnout_current)
301 		st->conf |= AD7793_CONF_BO_EN;
302 	if (pdata->unipolar)
303 		st->conf |= AD7793_CONF_UNIPOLAR;
304 
305 	if (!(st->chip_info->flags & AD7793_FLAG_HAS_GAIN))
306 		st->conf |= AD7793_CONF_GAIN(7);
307 
308 	ret = ad7793_set_mode(&st->sd, AD_SD_MODE_IDLE);
309 	if (ret)
310 		goto out;
311 
312 	ret = ad7793_set_channel(&st->sd, 0);
313 	if (ret)
314 		goto out;
315 
316 	if (st->chip_info->flags & AD7793_HAS_EXITATION_CURRENT) {
317 		ret = ad_sd_write_reg(&st->sd, AD7793_REG_IO, 1,
318 				pdata->exitation_current |
319 				(pdata->current_source_direction << 2));
320 		if (ret)
321 			goto out;
322 	}
323 
324 	ret = ad7793_calibrate_all(st);
325 	if (ret)
326 		goto out;
327 
328 	/* Populate available ADC input ranges */
329 	for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++) {
330 		scale_uv = ((u64)vref_mv * 100000000)
331 			>> (st->chip_info->channels[0].scan_type.realbits -
332 			(!!(st->conf & AD7793_CONF_UNIPOLAR) ? 0 : 1));
333 		scale_uv >>= i;
334 
335 		st->scale_avail[i][1] = do_div(scale_uv, 100000000) * 10;
336 		st->scale_avail[i][0] = scale_uv;
337 	}
338 
339 	return 0;
340 out:
341 	dev_err(&st->sd.spi->dev, "setup failed\n");
342 	return ret;
343 }
344 
345 static const u16 ad7793_sample_freq_avail[16] = {0, 470, 242, 123, 62, 50, 39,
346 					33, 19, 17, 16, 12, 10, 8, 6, 4};
347 
348 static const u16 ad7797_sample_freq_avail[16] = {0, 0, 0, 123, 62, 50, 0,
349 					33, 0, 17, 16, 12, 10, 8, 6, 4};
350 
351 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(
352 	"470 242 123 62 50 39 33 19 17 16 12 10 8 6 4");
353 
354 static IIO_CONST_ATTR_NAMED(sampling_frequency_available_ad7797,
355 	sampling_frequency_available, "123 62 50 33 17 16 12 10 8 6 4");
356 
357 static int ad7793_read_avail(struct iio_dev *indio_dev,
358 			     struct iio_chan_spec const *chan,
359 			     const int **vals, int *type, int *length,
360 			     long mask)
361 {
362 	struct ad7793_state *st = iio_priv(indio_dev);
363 
364 	switch (mask) {
365 	case IIO_CHAN_INFO_SCALE:
366 		*vals = (int *)st->scale_avail;
367 		*type = IIO_VAL_INT_PLUS_NANO;
368 		/* Values are stored in a 2D matrix  */
369 		*length = ARRAY_SIZE(st->scale_avail) * 2;
370 
371 		return IIO_AVAIL_LIST;
372 	default:
373 		return -EINVAL;
374 	}
375 }
376 
377 static struct attribute *ad7793_attributes[] = {
378 	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
379 	NULL
380 };
381 
382 static const struct attribute_group ad7793_attribute_group = {
383 	.attrs = ad7793_attributes,
384 };
385 
386 static struct attribute *ad7797_attributes[] = {
387 	&iio_const_attr_sampling_frequency_available_ad7797.dev_attr.attr,
388 	NULL
389 };
390 
391 static const struct attribute_group ad7797_attribute_group = {
392 	.attrs = ad7797_attributes,
393 };
394 
395 static int ad7793_read_raw(struct iio_dev *indio_dev,
396 			   struct iio_chan_spec const *chan,
397 			   int *val,
398 			   int *val2,
399 			   long m)
400 {
401 	struct ad7793_state *st = iio_priv(indio_dev);
402 	int ret;
403 	unsigned long long scale_uv;
404 	bool unipolar = !!(st->conf & AD7793_CONF_UNIPOLAR);
405 
406 	switch (m) {
407 	case IIO_CHAN_INFO_RAW:
408 		ret = ad_sigma_delta_single_conversion(indio_dev, chan, val);
409 		if (ret < 0)
410 			return ret;
411 
412 		return IIO_VAL_INT;
413 
414 	case IIO_CHAN_INFO_SCALE:
415 		switch (chan->type) {
416 		case IIO_VOLTAGE:
417 			if (chan->differential) {
418 				*val = st->
419 					scale_avail[(st->conf >> 8) & 0x7][0];
420 				*val2 = st->
421 					scale_avail[(st->conf >> 8) & 0x7][1];
422 				return IIO_VAL_INT_PLUS_NANO;
423 			}
424 			/* 1170mV / 2^23 * 6 */
425 			scale_uv = (1170ULL * 1000000000ULL * 6ULL);
426 			break;
427 		case IIO_TEMP:
428 				/* 1170mV / 0.81 mV/C / 2^23 */
429 				scale_uv = 1444444444444444ULL;
430 			break;
431 		default:
432 			return -EINVAL;
433 		}
434 
435 		scale_uv >>= (chan->scan_type.realbits - (unipolar ? 0 : 1));
436 		*val = 0;
437 		*val2 = scale_uv;
438 		return IIO_VAL_INT_PLUS_NANO;
439 	case IIO_CHAN_INFO_OFFSET:
440 		if (!unipolar)
441 			*val = -(1 << (chan->scan_type.realbits - 1));
442 		else
443 			*val = 0;
444 
445 		/* Kelvin to Celsius */
446 		if (chan->type == IIO_TEMP) {
447 			unsigned long long offset;
448 			unsigned int shift;
449 
450 			shift = chan->scan_type.realbits - (unipolar ? 0 : 1);
451 			offset = 273ULL << shift;
452 			do_div(offset, 1444);
453 			*val -= offset;
454 		}
455 		return IIO_VAL_INT;
456 	case IIO_CHAN_INFO_SAMP_FREQ:
457 		*val = st->chip_info
458 			       ->sample_freq_avail[AD7793_MODE_RATE(st->mode)];
459 		return IIO_VAL_INT;
460 	}
461 	return -EINVAL;
462 }
463 
464 static int ad7793_write_raw(struct iio_dev *indio_dev,
465 			       struct iio_chan_spec const *chan,
466 			       int val,
467 			       int val2,
468 			       long mask)
469 {
470 	struct ad7793_state *st = iio_priv(indio_dev);
471 	int ret, i;
472 	unsigned int tmp;
473 
474 	ret = iio_device_claim_direct_mode(indio_dev);
475 	if (ret)
476 		return ret;
477 
478 	switch (mask) {
479 	case IIO_CHAN_INFO_SCALE:
480 		ret = -EINVAL;
481 		for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++)
482 			if (val2 == st->scale_avail[i][1]) {
483 				ret = 0;
484 				tmp = st->conf;
485 				st->conf &= ~AD7793_CONF_GAIN(-1);
486 				st->conf |= AD7793_CONF_GAIN(i);
487 
488 				if (tmp == st->conf)
489 					break;
490 
491 				ad_sd_write_reg(&st->sd, AD7793_REG_CONF,
492 						sizeof(st->conf), st->conf);
493 				ad7793_calibrate_all(st);
494 				break;
495 			}
496 		break;
497 	case IIO_CHAN_INFO_SAMP_FREQ:
498 		if (!val) {
499 			ret = -EINVAL;
500 			break;
501 		}
502 
503 		for (i = 0; i < 16; i++)
504 			if (val == st->chip_info->sample_freq_avail[i])
505 				break;
506 
507 		if (i == 16) {
508 			ret = -EINVAL;
509 			break;
510 		}
511 
512 		st->mode &= ~AD7793_MODE_RATE(-1);
513 		st->mode |= AD7793_MODE_RATE(i);
514 		ad_sd_write_reg(&st->sd, AD7793_REG_MODE, sizeof(st->mode),
515 				st->mode);
516 		break;
517 	default:
518 		ret = -EINVAL;
519 	}
520 
521 	iio_device_release_direct_mode(indio_dev);
522 	return ret;
523 }
524 
525 static int ad7793_write_raw_get_fmt(struct iio_dev *indio_dev,
526 			       struct iio_chan_spec const *chan,
527 			       long mask)
528 {
529 	return IIO_VAL_INT_PLUS_NANO;
530 }
531 
532 static const struct iio_info ad7793_info = {
533 	.read_raw = &ad7793_read_raw,
534 	.write_raw = &ad7793_write_raw,
535 	.write_raw_get_fmt = &ad7793_write_raw_get_fmt,
536 	.read_avail = ad7793_read_avail,
537 	.attrs = &ad7793_attribute_group,
538 	.validate_trigger = ad_sd_validate_trigger,
539 };
540 
541 static const struct iio_info ad7797_info = {
542 	.read_raw = &ad7793_read_raw,
543 	.write_raw = &ad7793_write_raw,
544 	.write_raw_get_fmt = &ad7793_write_raw_get_fmt,
545 	.attrs = &ad7797_attribute_group,
546 	.validate_trigger = ad_sd_validate_trigger,
547 };
548 
549 #define __AD7793_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
550 	_storagebits, _shift, _extend_name, _type, _mask_type_av, _mask_all) \
551 	{ \
552 		.type = (_type), \
553 		.differential = (_channel2 == -1 ? 0 : 1), \
554 		.indexed = 1, \
555 		.channel = (_channel1), \
556 		.channel2 = (_channel2), \
557 		.address = (_address), \
558 		.extend_name = (_extend_name), \
559 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
560 			BIT(IIO_CHAN_INFO_OFFSET), \
561 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
562 		.info_mask_shared_by_type_available = (_mask_type_av), \
563 		.info_mask_shared_by_all = _mask_all, \
564 		.scan_index = (_si), \
565 		.scan_type = { \
566 			.sign = 'u', \
567 			.realbits = (_bits), \
568 			.storagebits = (_storagebits), \
569 			.shift = (_shift), \
570 			.endianness = IIO_BE, \
571 		}, \
572 	}
573 
574 #define AD7793_DIFF_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
575 	_storagebits, _shift) \
576 	__AD7793_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
577 		_storagebits, _shift, NULL, IIO_VOLTAGE, \
578 		BIT(IIO_CHAN_INFO_SCALE), \
579 		BIT(IIO_CHAN_INFO_SAMP_FREQ))
580 
581 #define AD7793_SHORTED_CHANNEL(_si, _channel, _address, _bits, \
582 	_storagebits, _shift) \
583 	__AD7793_CHANNEL(_si, _channel, _channel, _address, _bits, \
584 		_storagebits, _shift, "shorted", IIO_VOLTAGE, \
585 		BIT(IIO_CHAN_INFO_SCALE), \
586 		BIT(IIO_CHAN_INFO_SAMP_FREQ))
587 
588 #define AD7793_TEMP_CHANNEL(_si, _address, _bits, _storagebits, _shift) \
589 	__AD7793_CHANNEL(_si, 0, -1, _address, _bits, \
590 		_storagebits, _shift, NULL, IIO_TEMP, \
591 		0, \
592 		BIT(IIO_CHAN_INFO_SAMP_FREQ))
593 
594 #define AD7793_SUPPLY_CHANNEL(_si, _channel, _address, _bits, _storagebits, \
595 	_shift) \
596 	__AD7793_CHANNEL(_si, _channel, -1, _address, _bits, \
597 		_storagebits, _shift, "supply", IIO_VOLTAGE, \
598 		0, \
599 		BIT(IIO_CHAN_INFO_SAMP_FREQ))
600 
601 #define AD7797_DIFF_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
602 	_storagebits, _shift) \
603 	__AD7793_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
604 		_storagebits, _shift, NULL, IIO_VOLTAGE, \
605 		0, \
606 		BIT(IIO_CHAN_INFO_SAMP_FREQ))
607 
608 #define AD7797_SHORTED_CHANNEL(_si, _channel, _address, _bits, \
609 	_storagebits, _shift) \
610 	__AD7793_CHANNEL(_si, _channel, _channel, _address, _bits, \
611 		_storagebits, _shift, "shorted", IIO_VOLTAGE, \
612 		0, \
613 		BIT(IIO_CHAN_INFO_SAMP_FREQ))
614 
615 #define DECLARE_AD7793_CHANNELS(_name, _b, _sb, _s) \
616 const struct iio_chan_spec _name##_channels[] = { \
617 	AD7793_DIFF_CHANNEL(0, 0, 0, AD7793_CH_AIN1P_AIN1M, (_b), (_sb), (_s)), \
618 	AD7793_DIFF_CHANNEL(1, 1, 1, AD7793_CH_AIN2P_AIN2M, (_b), (_sb), (_s)), \
619 	AD7793_DIFF_CHANNEL(2, 2, 2, AD7793_CH_AIN3P_AIN3M, (_b), (_sb), (_s)), \
620 	AD7793_SHORTED_CHANNEL(3, 0, AD7793_CH_AIN1M_AIN1M, (_b), (_sb), (_s)), \
621 	AD7793_TEMP_CHANNEL(4, AD7793_CH_TEMP, (_b), (_sb), (_s)), \
622 	AD7793_SUPPLY_CHANNEL(5, 3, AD7793_CH_AVDD_MONITOR, (_b), (_sb), (_s)), \
623 	IIO_CHAN_SOFT_TIMESTAMP(6), \
624 }
625 
626 #define DECLARE_AD7795_CHANNELS(_name, _b, _sb) \
627 const struct iio_chan_spec _name##_channels[] = { \
628 	AD7793_DIFF_CHANNEL(0, 0, 0, AD7793_CH_AIN1P_AIN1M, (_b), (_sb), 0), \
629 	AD7793_DIFF_CHANNEL(1, 1, 1, AD7793_CH_AIN2P_AIN2M, (_b), (_sb), 0), \
630 	AD7793_DIFF_CHANNEL(2, 2, 2, AD7793_CH_AIN3P_AIN3M, (_b), (_sb), 0), \
631 	AD7793_DIFF_CHANNEL(3, 3, 3, AD7795_CH_AIN4P_AIN4M, (_b), (_sb), 0), \
632 	AD7793_DIFF_CHANNEL(4, 4, 4, AD7795_CH_AIN5P_AIN5M, (_b), (_sb), 0), \
633 	AD7793_DIFF_CHANNEL(5, 5, 5, AD7795_CH_AIN6P_AIN6M, (_b), (_sb), 0), \
634 	AD7793_SHORTED_CHANNEL(6, 0, AD7795_CH_AIN1M_AIN1M, (_b), (_sb), 0), \
635 	AD7793_TEMP_CHANNEL(7, AD7793_CH_TEMP, (_b), (_sb), 0), \
636 	AD7793_SUPPLY_CHANNEL(8, 3, AD7793_CH_AVDD_MONITOR, (_b), (_sb), 0), \
637 	IIO_CHAN_SOFT_TIMESTAMP(9), \
638 }
639 
640 #define DECLARE_AD7797_CHANNELS(_name, _b, _sb) \
641 const struct iio_chan_spec _name##_channels[] = { \
642 	AD7797_DIFF_CHANNEL(0, 0, 0, AD7793_CH_AIN1P_AIN1M, (_b), (_sb), 0), \
643 	AD7797_SHORTED_CHANNEL(1, 0, AD7793_CH_AIN1M_AIN1M, (_b), (_sb), 0), \
644 	AD7793_TEMP_CHANNEL(2, AD7793_CH_TEMP, (_b), (_sb), 0), \
645 	AD7793_SUPPLY_CHANNEL(3, 3, AD7793_CH_AVDD_MONITOR, (_b), (_sb), 0), \
646 	IIO_CHAN_SOFT_TIMESTAMP(4), \
647 }
648 
649 #define DECLARE_AD7799_CHANNELS(_name, _b, _sb) \
650 const struct iio_chan_spec _name##_channels[] = { \
651 	AD7793_DIFF_CHANNEL(0, 0, 0, AD7793_CH_AIN1P_AIN1M, (_b), (_sb), 0), \
652 	AD7793_DIFF_CHANNEL(1, 1, 1, AD7793_CH_AIN2P_AIN2M, (_b), (_sb), 0), \
653 	AD7793_DIFF_CHANNEL(2, 2, 2, AD7793_CH_AIN3P_AIN3M, (_b), (_sb), 0), \
654 	AD7793_SHORTED_CHANNEL(3, 0, AD7793_CH_AIN1M_AIN1M, (_b), (_sb), 0), \
655 	AD7793_SUPPLY_CHANNEL(4, 3, AD7793_CH_AVDD_MONITOR, (_b), (_sb), 0), \
656 	IIO_CHAN_SOFT_TIMESTAMP(5), \
657 }
658 
659 static DECLARE_AD7793_CHANNELS(ad7785, 20, 32, 4);
660 static DECLARE_AD7793_CHANNELS(ad7792, 16, 32, 0);
661 static DECLARE_AD7793_CHANNELS(ad7793, 24, 32, 0);
662 static DECLARE_AD7795_CHANNELS(ad7794, 16, 32);
663 static DECLARE_AD7795_CHANNELS(ad7795, 24, 32);
664 static DECLARE_AD7797_CHANNELS(ad7796, 16, 16);
665 static DECLARE_AD7797_CHANNELS(ad7797, 24, 32);
666 static DECLARE_AD7799_CHANNELS(ad7798, 16, 16);
667 static DECLARE_AD7799_CHANNELS(ad7799, 24, 32);
668 
669 static const struct ad7793_chip_info ad7793_chip_info_tbl[] = {
670 	[ID_AD7785] = {
671 		.id = AD7785_ID,
672 		.channels = ad7785_channels,
673 		.num_channels = ARRAY_SIZE(ad7785_channels),
674 		.iio_info = &ad7793_info,
675 		.sample_freq_avail = ad7793_sample_freq_avail,
676 		.flags = AD7793_FLAG_HAS_CLKSEL |
677 			AD7793_FLAG_HAS_REFSEL |
678 			AD7793_FLAG_HAS_VBIAS |
679 			AD7793_HAS_EXITATION_CURRENT |
680 			AD7793_FLAG_HAS_GAIN |
681 			AD7793_FLAG_HAS_BUFFER,
682 	},
683 	[ID_AD7792] = {
684 		.id = AD7792_ID,
685 		.channels = ad7792_channels,
686 		.num_channels = ARRAY_SIZE(ad7792_channels),
687 		.iio_info = &ad7793_info,
688 		.sample_freq_avail = ad7793_sample_freq_avail,
689 		.flags = AD7793_FLAG_HAS_CLKSEL |
690 			AD7793_FLAG_HAS_REFSEL |
691 			AD7793_FLAG_HAS_VBIAS |
692 			AD7793_HAS_EXITATION_CURRENT |
693 			AD7793_FLAG_HAS_GAIN |
694 			AD7793_FLAG_HAS_BUFFER,
695 	},
696 	[ID_AD7793] = {
697 		.id = AD7793_ID,
698 		.channels = ad7793_channels,
699 		.num_channels = ARRAY_SIZE(ad7793_channels),
700 		.iio_info = &ad7793_info,
701 		.sample_freq_avail = ad7793_sample_freq_avail,
702 		.flags = AD7793_FLAG_HAS_CLKSEL |
703 			AD7793_FLAG_HAS_REFSEL |
704 			AD7793_FLAG_HAS_VBIAS |
705 			AD7793_HAS_EXITATION_CURRENT |
706 			AD7793_FLAG_HAS_GAIN |
707 			AD7793_FLAG_HAS_BUFFER,
708 	},
709 	[ID_AD7794] = {
710 		.id = AD7794_ID,
711 		.channels = ad7794_channels,
712 		.num_channels = ARRAY_SIZE(ad7794_channels),
713 		.iio_info = &ad7793_info,
714 		.sample_freq_avail = ad7793_sample_freq_avail,
715 		.flags = AD7793_FLAG_HAS_CLKSEL |
716 			AD7793_FLAG_HAS_REFSEL |
717 			AD7793_FLAG_HAS_VBIAS |
718 			AD7793_HAS_EXITATION_CURRENT |
719 			AD7793_FLAG_HAS_GAIN |
720 			AD7793_FLAG_HAS_BUFFER,
721 	},
722 	[ID_AD7795] = {
723 		.id = AD7795_ID,
724 		.channels = ad7795_channels,
725 		.num_channels = ARRAY_SIZE(ad7795_channels),
726 		.iio_info = &ad7793_info,
727 		.sample_freq_avail = ad7793_sample_freq_avail,
728 		.flags = AD7793_FLAG_HAS_CLKSEL |
729 			AD7793_FLAG_HAS_REFSEL |
730 			AD7793_FLAG_HAS_VBIAS |
731 			AD7793_HAS_EXITATION_CURRENT |
732 			AD7793_FLAG_HAS_GAIN |
733 			AD7793_FLAG_HAS_BUFFER,
734 	},
735 	[ID_AD7796] = {
736 		.id = AD7796_ID,
737 		.channels = ad7796_channels,
738 		.num_channels = ARRAY_SIZE(ad7796_channels),
739 		.iio_info = &ad7797_info,
740 		.sample_freq_avail = ad7797_sample_freq_avail,
741 		.flags = AD7793_FLAG_HAS_CLKSEL,
742 	},
743 	[ID_AD7797] = {
744 		.id = AD7797_ID,
745 		.channels = ad7797_channels,
746 		.num_channels = ARRAY_SIZE(ad7797_channels),
747 		.iio_info = &ad7797_info,
748 		.sample_freq_avail = ad7797_sample_freq_avail,
749 		.flags = AD7793_FLAG_HAS_CLKSEL,
750 	},
751 	[ID_AD7798] = {
752 		.id = AD7798_ID,
753 		.channels = ad7798_channels,
754 		.num_channels = ARRAY_SIZE(ad7798_channels),
755 		.iio_info = &ad7793_info,
756 		.sample_freq_avail = ad7793_sample_freq_avail,
757 		.flags = AD7793_FLAG_HAS_GAIN |
758 			AD7793_FLAG_HAS_BUFFER,
759 	},
760 	[ID_AD7799] = {
761 		.id = AD7799_ID,
762 		.channels = ad7799_channels,
763 		.num_channels = ARRAY_SIZE(ad7799_channels),
764 		.iio_info = &ad7793_info,
765 		.sample_freq_avail = ad7793_sample_freq_avail,
766 		.flags = AD7793_FLAG_HAS_GAIN |
767 			AD7793_FLAG_HAS_BUFFER,
768 	},
769 };
770 
771 static int ad7793_probe(struct spi_device *spi)
772 {
773 	const struct ad7793_platform_data *pdata = spi->dev.platform_data;
774 	struct ad7793_state *st;
775 	struct iio_dev *indio_dev;
776 	int ret, vref_mv = 0;
777 
778 	if (!pdata) {
779 		dev_err(&spi->dev, "no platform data?\n");
780 		return -ENODEV;
781 	}
782 
783 	if (!spi->irq) {
784 		dev_err(&spi->dev, "no IRQ?\n");
785 		return -ENODEV;
786 	}
787 
788 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
789 	if (indio_dev == NULL)
790 		return -ENOMEM;
791 
792 	st = iio_priv(indio_dev);
793 
794 	ad_sd_init(&st->sd, indio_dev, spi, &ad7793_sigma_delta_info);
795 
796 	if (pdata->refsel != AD7793_REFSEL_INTERNAL) {
797 		st->reg = devm_regulator_get(&spi->dev, "refin");
798 		if (IS_ERR(st->reg))
799 			return PTR_ERR(st->reg);
800 
801 		ret = regulator_enable(st->reg);
802 		if (ret)
803 			return ret;
804 
805 		vref_mv = regulator_get_voltage(st->reg);
806 		if (vref_mv < 0) {
807 			ret = vref_mv;
808 			goto error_disable_reg;
809 		}
810 
811 		vref_mv /= 1000;
812 	} else {
813 		vref_mv = 1170; /* Build-in ref */
814 	}
815 
816 	st->chip_info =
817 		&ad7793_chip_info_tbl[spi_get_device_id(spi)->driver_data];
818 
819 	spi_set_drvdata(spi, indio_dev);
820 
821 	indio_dev->name = spi_get_device_id(spi)->name;
822 	indio_dev->modes = INDIO_DIRECT_MODE;
823 	indio_dev->channels = st->chip_info->channels;
824 	indio_dev->num_channels = st->chip_info->num_channels;
825 	indio_dev->info = st->chip_info->iio_info;
826 
827 	ret = ad_sd_setup_buffer_and_trigger(indio_dev);
828 	if (ret)
829 		goto error_disable_reg;
830 
831 	ret = ad7793_setup(indio_dev, pdata, vref_mv);
832 	if (ret)
833 		goto error_remove_trigger;
834 
835 	ret = iio_device_register(indio_dev);
836 	if (ret)
837 		goto error_remove_trigger;
838 
839 	return 0;
840 
841 error_remove_trigger:
842 	ad_sd_cleanup_buffer_and_trigger(indio_dev);
843 error_disable_reg:
844 	if (pdata->refsel != AD7793_REFSEL_INTERNAL)
845 		regulator_disable(st->reg);
846 
847 	return ret;
848 }
849 
850 static int ad7793_remove(struct spi_device *spi)
851 {
852 	const struct ad7793_platform_data *pdata = spi->dev.platform_data;
853 	struct iio_dev *indio_dev = spi_get_drvdata(spi);
854 	struct ad7793_state *st = iio_priv(indio_dev);
855 
856 	iio_device_unregister(indio_dev);
857 	ad_sd_cleanup_buffer_and_trigger(indio_dev);
858 
859 	if (pdata->refsel != AD7793_REFSEL_INTERNAL)
860 		regulator_disable(st->reg);
861 
862 	return 0;
863 }
864 
865 static const struct spi_device_id ad7793_id[] = {
866 	{"ad7785", ID_AD7785},
867 	{"ad7792", ID_AD7792},
868 	{"ad7793", ID_AD7793},
869 	{"ad7794", ID_AD7794},
870 	{"ad7795", ID_AD7795},
871 	{"ad7796", ID_AD7796},
872 	{"ad7797", ID_AD7797},
873 	{"ad7798", ID_AD7798},
874 	{"ad7799", ID_AD7799},
875 	{}
876 };
877 MODULE_DEVICE_TABLE(spi, ad7793_id);
878 
879 static struct spi_driver ad7793_driver = {
880 	.driver = {
881 		.name	= "ad7793",
882 	},
883 	.probe		= ad7793_probe,
884 	.remove		= ad7793_remove,
885 	.id_table	= ad7793_id,
886 };
887 module_spi_driver(ad7793_driver);
888 
889 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
890 MODULE_DESCRIPTION("Analog Devices AD7793 and similar ADCs");
891 MODULE_LICENSE("GPL v2");
892