xref: /openbmc/linux/drivers/iio/adc/ad7793.c (revision 8dde5715)
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 };
210 
211 static const struct ad_sd_calib_data ad7793_calib_arr[6] = {
212 	{AD7793_MODE_CAL_INT_ZERO, AD7793_CH_AIN1P_AIN1M},
213 	{AD7793_MODE_CAL_INT_FULL, AD7793_CH_AIN1P_AIN1M},
214 	{AD7793_MODE_CAL_INT_ZERO, AD7793_CH_AIN2P_AIN2M},
215 	{AD7793_MODE_CAL_INT_FULL, AD7793_CH_AIN2P_AIN2M},
216 	{AD7793_MODE_CAL_INT_ZERO, AD7793_CH_AIN3P_AIN3M},
217 	{AD7793_MODE_CAL_INT_FULL, AD7793_CH_AIN3P_AIN3M}
218 };
219 
220 static int ad7793_calibrate_all(struct ad7793_state *st)
221 {
222 	return ad_sd_calibrate_all(&st->sd, ad7793_calib_arr,
223 				   ARRAY_SIZE(ad7793_calib_arr));
224 }
225 
226 static int ad7793_check_platform_data(struct ad7793_state *st,
227 	const struct ad7793_platform_data *pdata)
228 {
229 	if ((pdata->current_source_direction == AD7793_IEXEC1_IEXEC2_IOUT1 ||
230 		pdata->current_source_direction == AD7793_IEXEC1_IEXEC2_IOUT2) &&
231 		((pdata->exitation_current != AD7793_IX_10uA) &&
232 		(pdata->exitation_current != AD7793_IX_210uA)))
233 		return -EINVAL;
234 
235 	if (!(st->chip_info->flags & AD7793_FLAG_HAS_CLKSEL) &&
236 		pdata->clock_src != AD7793_CLK_SRC_INT)
237 		return -EINVAL;
238 
239 	if (!(st->chip_info->flags & AD7793_FLAG_HAS_REFSEL) &&
240 		pdata->refsel != AD7793_REFSEL_REFIN1)
241 		return -EINVAL;
242 
243 	if (!(st->chip_info->flags & AD7793_FLAG_HAS_VBIAS) &&
244 		pdata->bias_voltage != AD7793_BIAS_VOLTAGE_DISABLED)
245 		return -EINVAL;
246 
247 	if (!(st->chip_info->flags & AD7793_HAS_EXITATION_CURRENT) &&
248 		pdata->exitation_current != AD7793_IX_DISABLED)
249 		return -EINVAL;
250 
251 	return 0;
252 }
253 
254 static int ad7793_setup(struct iio_dev *indio_dev,
255 	const struct ad7793_platform_data *pdata,
256 	unsigned int vref_mv)
257 {
258 	struct ad7793_state *st = iio_priv(indio_dev);
259 	int i, ret;
260 	unsigned long long scale_uv;
261 	u32 id;
262 
263 	ret = ad7793_check_platform_data(st, pdata);
264 	if (ret)
265 		return ret;
266 
267 	/* reset the serial interface */
268 	ret = ad_sd_reset(&st->sd, 32);
269 	if (ret < 0)
270 		goto out;
271 	usleep_range(500, 2000); /* Wait for at least 500us */
272 
273 	/* write/read test for device presence */
274 	ret = ad_sd_read_reg(&st->sd, AD7793_REG_ID, 1, &id);
275 	if (ret)
276 		goto out;
277 
278 	id &= AD7793_ID_MASK;
279 
280 	if (id != st->chip_info->id) {
281 		dev_err(&st->sd.spi->dev, "device ID query failed\n");
282 		goto out;
283 	}
284 
285 	st->mode = AD7793_MODE_RATE(1);
286 	st->conf = 0;
287 
288 	if (st->chip_info->flags & AD7793_FLAG_HAS_CLKSEL)
289 		st->mode |= AD7793_MODE_CLKSRC(pdata->clock_src);
290 	if (st->chip_info->flags & AD7793_FLAG_HAS_REFSEL)
291 		st->conf |= AD7793_CONF_REFSEL(pdata->refsel);
292 	if (st->chip_info->flags & AD7793_FLAG_HAS_VBIAS)
293 		st->conf |= AD7793_CONF_VBIAS(pdata->bias_voltage);
294 	if (pdata->buffered || !(st->chip_info->flags & AD7793_FLAG_HAS_BUFFER))
295 		st->conf |= AD7793_CONF_BUF;
296 	if (pdata->boost_enable &&
297 		(st->chip_info->flags & AD7793_FLAG_HAS_VBIAS))
298 		st->conf |= AD7793_CONF_BOOST;
299 	if (pdata->burnout_current)
300 		st->conf |= AD7793_CONF_BO_EN;
301 	if (pdata->unipolar)
302 		st->conf |= AD7793_CONF_UNIPOLAR;
303 
304 	if (!(st->chip_info->flags & AD7793_FLAG_HAS_GAIN))
305 		st->conf |= AD7793_CONF_GAIN(7);
306 
307 	ret = ad7793_set_mode(&st->sd, AD_SD_MODE_IDLE);
308 	if (ret)
309 		goto out;
310 
311 	ret = ad7793_set_channel(&st->sd, 0);
312 	if (ret)
313 		goto out;
314 
315 	if (st->chip_info->flags & AD7793_HAS_EXITATION_CURRENT) {
316 		ret = ad_sd_write_reg(&st->sd, AD7793_REG_IO, 1,
317 				pdata->exitation_current |
318 				(pdata->current_source_direction << 2));
319 		if (ret)
320 			goto out;
321 	}
322 
323 	ret = ad7793_calibrate_all(st);
324 	if (ret)
325 		goto out;
326 
327 	/* Populate available ADC input ranges */
328 	for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++) {
329 		scale_uv = ((u64)vref_mv * 100000000)
330 			>> (st->chip_info->channels[0].scan_type.realbits -
331 			(!!(st->conf & AD7793_CONF_UNIPOLAR) ? 0 : 1));
332 		scale_uv >>= i;
333 
334 		st->scale_avail[i][1] = do_div(scale_uv, 100000000) * 10;
335 		st->scale_avail[i][0] = scale_uv;
336 	}
337 
338 	return 0;
339 out:
340 	dev_err(&st->sd.spi->dev, "setup failed\n");
341 	return ret;
342 }
343 
344 static const u16 ad7793_sample_freq_avail[16] = {0, 470, 242, 123, 62, 50, 39,
345 					33, 19, 17, 16, 12, 10, 8, 6, 4};
346 
347 static const u16 ad7797_sample_freq_avail[16] = {0, 0, 0, 123, 62, 50, 0,
348 					33, 0, 17, 16, 12, 10, 8, 6, 4};
349 
350 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(
351 	"470 242 123 62 50 39 33 19 17 16 12 10 8 6 4");
352 
353 static IIO_CONST_ATTR_NAMED(sampling_frequency_available_ad7797,
354 	sampling_frequency_available, "123 62 50 33 17 16 12 10 8 6 4");
355 
356 static ssize_t ad7793_show_scale_available(struct device *dev,
357 			struct device_attribute *attr, char *buf)
358 {
359 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
360 	struct ad7793_state *st = iio_priv(indio_dev);
361 	int i, len = 0;
362 
363 	for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++)
364 		len += sprintf(buf + len, "%d.%09u ", st->scale_avail[i][0],
365 			       st->scale_avail[i][1]);
366 
367 	len += sprintf(buf + len, "\n");
368 
369 	return len;
370 }
371 
372 static IIO_DEVICE_ATTR_NAMED(in_m_in_scale_available,
373 		in_voltage-voltage_scale_available, S_IRUGO,
374 		ad7793_show_scale_available, NULL, 0);
375 
376 static struct attribute *ad7793_attributes[] = {
377 	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
378 	&iio_dev_attr_in_m_in_scale_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 	.attrs = &ad7793_attribute_group,
537 	.validate_trigger = ad_sd_validate_trigger,
538 };
539 
540 static const struct iio_info ad7797_info = {
541 	.read_raw = &ad7793_read_raw,
542 	.write_raw = &ad7793_write_raw,
543 	.write_raw_get_fmt = &ad7793_write_raw_get_fmt,
544 	.attrs = &ad7793_attribute_group,
545 	.validate_trigger = ad_sd_validate_trigger,
546 };
547 
548 #define DECLARE_AD7793_CHANNELS(_name, _b, _sb, _s) \
549 const struct iio_chan_spec _name##_channels[] = { \
550 	AD_SD_DIFF_CHANNEL(0, 0, 0, AD7793_CH_AIN1P_AIN1M, (_b), (_sb), (_s)), \
551 	AD_SD_DIFF_CHANNEL(1, 1, 1, AD7793_CH_AIN2P_AIN2M, (_b), (_sb), (_s)), \
552 	AD_SD_DIFF_CHANNEL(2, 2, 2, AD7793_CH_AIN3P_AIN3M, (_b), (_sb), (_s)), \
553 	AD_SD_SHORTED_CHANNEL(3, 0, AD7793_CH_AIN1M_AIN1M, (_b), (_sb), (_s)), \
554 	AD_SD_TEMP_CHANNEL(4, AD7793_CH_TEMP, (_b), (_sb), (_s)), \
555 	AD_SD_SUPPLY_CHANNEL(5, 3, AD7793_CH_AVDD_MONITOR, (_b), (_sb), (_s)), \
556 	IIO_CHAN_SOFT_TIMESTAMP(6), \
557 }
558 
559 #define DECLARE_AD7795_CHANNELS(_name, _b, _sb) \
560 const struct iio_chan_spec _name##_channels[] = { \
561 	AD_SD_DIFF_CHANNEL(0, 0, 0, AD7793_CH_AIN1P_AIN1M, (_b), (_sb), 0), \
562 	AD_SD_DIFF_CHANNEL(1, 1, 1, AD7793_CH_AIN2P_AIN2M, (_b), (_sb), 0), \
563 	AD_SD_DIFF_CHANNEL(2, 2, 2, AD7793_CH_AIN3P_AIN3M, (_b), (_sb), 0), \
564 	AD_SD_DIFF_CHANNEL(3, 3, 3, AD7795_CH_AIN4P_AIN4M, (_b), (_sb), 0), \
565 	AD_SD_DIFF_CHANNEL(4, 4, 4, AD7795_CH_AIN5P_AIN5M, (_b), (_sb), 0), \
566 	AD_SD_DIFF_CHANNEL(5, 5, 5, AD7795_CH_AIN6P_AIN6M, (_b), (_sb), 0), \
567 	AD_SD_SHORTED_CHANNEL(6, 0, AD7795_CH_AIN1M_AIN1M, (_b), (_sb), 0), \
568 	AD_SD_TEMP_CHANNEL(7, AD7793_CH_TEMP, (_b), (_sb), 0), \
569 	AD_SD_SUPPLY_CHANNEL(8, 3, AD7793_CH_AVDD_MONITOR, (_b), (_sb), 0), \
570 	IIO_CHAN_SOFT_TIMESTAMP(9), \
571 }
572 
573 #define DECLARE_AD7797_CHANNELS(_name, _b, _sb) \
574 const struct iio_chan_spec _name##_channels[] = { \
575 	AD_SD_DIFF_CHANNEL(0, 0, 0, AD7793_CH_AIN1P_AIN1M, (_b), (_sb), 0), \
576 	AD_SD_SHORTED_CHANNEL(1, 0, AD7793_CH_AIN1M_AIN1M, (_b), (_sb), 0), \
577 	AD_SD_TEMP_CHANNEL(2, AD7793_CH_TEMP, (_b), (_sb), 0), \
578 	AD_SD_SUPPLY_CHANNEL(3, 3, AD7793_CH_AVDD_MONITOR, (_b), (_sb), 0), \
579 	IIO_CHAN_SOFT_TIMESTAMP(4), \
580 }
581 
582 #define DECLARE_AD7799_CHANNELS(_name, _b, _sb) \
583 const struct iio_chan_spec _name##_channels[] = { \
584 	AD_SD_DIFF_CHANNEL(0, 0, 0, AD7793_CH_AIN1P_AIN1M, (_b), (_sb), 0), \
585 	AD_SD_DIFF_CHANNEL(1, 1, 1, AD7793_CH_AIN2P_AIN2M, (_b), (_sb), 0), \
586 	AD_SD_DIFF_CHANNEL(2, 2, 2, AD7793_CH_AIN3P_AIN3M, (_b), (_sb), 0), \
587 	AD_SD_SHORTED_CHANNEL(3, 0, AD7793_CH_AIN1M_AIN1M, (_b), (_sb), 0), \
588 	AD_SD_SUPPLY_CHANNEL(4, 3, AD7793_CH_AVDD_MONITOR, (_b), (_sb), 0), \
589 	IIO_CHAN_SOFT_TIMESTAMP(5), \
590 }
591 
592 static DECLARE_AD7793_CHANNELS(ad7785, 20, 32, 4);
593 static DECLARE_AD7793_CHANNELS(ad7792, 16, 32, 0);
594 static DECLARE_AD7793_CHANNELS(ad7793, 24, 32, 0);
595 static DECLARE_AD7795_CHANNELS(ad7794, 16, 32);
596 static DECLARE_AD7795_CHANNELS(ad7795, 24, 32);
597 static DECLARE_AD7797_CHANNELS(ad7796, 16, 16);
598 static DECLARE_AD7797_CHANNELS(ad7797, 24, 32);
599 static DECLARE_AD7799_CHANNELS(ad7798, 16, 16);
600 static DECLARE_AD7799_CHANNELS(ad7799, 24, 32);
601 
602 static const struct ad7793_chip_info ad7793_chip_info_tbl[] = {
603 	[ID_AD7785] = {
604 		.id = AD7785_ID,
605 		.channels = ad7785_channels,
606 		.num_channels = ARRAY_SIZE(ad7785_channels),
607 		.iio_info = &ad7793_info,
608 		.sample_freq_avail = ad7793_sample_freq_avail,
609 		.flags = AD7793_FLAG_HAS_CLKSEL |
610 			AD7793_FLAG_HAS_REFSEL |
611 			AD7793_FLAG_HAS_VBIAS |
612 			AD7793_HAS_EXITATION_CURRENT |
613 			AD7793_FLAG_HAS_GAIN |
614 			AD7793_FLAG_HAS_BUFFER,
615 	},
616 	[ID_AD7792] = {
617 		.id = AD7792_ID,
618 		.channels = ad7792_channels,
619 		.num_channels = ARRAY_SIZE(ad7792_channels),
620 		.iio_info = &ad7793_info,
621 		.sample_freq_avail = ad7793_sample_freq_avail,
622 		.flags = AD7793_FLAG_HAS_CLKSEL |
623 			AD7793_FLAG_HAS_REFSEL |
624 			AD7793_FLAG_HAS_VBIAS |
625 			AD7793_HAS_EXITATION_CURRENT |
626 			AD7793_FLAG_HAS_GAIN |
627 			AD7793_FLAG_HAS_BUFFER,
628 	},
629 	[ID_AD7793] = {
630 		.id = AD7793_ID,
631 		.channels = ad7793_channels,
632 		.num_channels = ARRAY_SIZE(ad7793_channels),
633 		.iio_info = &ad7793_info,
634 		.sample_freq_avail = ad7793_sample_freq_avail,
635 		.flags = AD7793_FLAG_HAS_CLKSEL |
636 			AD7793_FLAG_HAS_REFSEL |
637 			AD7793_FLAG_HAS_VBIAS |
638 			AD7793_HAS_EXITATION_CURRENT |
639 			AD7793_FLAG_HAS_GAIN |
640 			AD7793_FLAG_HAS_BUFFER,
641 	},
642 	[ID_AD7794] = {
643 		.id = AD7794_ID,
644 		.channels = ad7794_channels,
645 		.num_channels = ARRAY_SIZE(ad7794_channels),
646 		.iio_info = &ad7793_info,
647 		.sample_freq_avail = ad7793_sample_freq_avail,
648 		.flags = AD7793_FLAG_HAS_CLKSEL |
649 			AD7793_FLAG_HAS_REFSEL |
650 			AD7793_FLAG_HAS_VBIAS |
651 			AD7793_HAS_EXITATION_CURRENT |
652 			AD7793_FLAG_HAS_GAIN |
653 			AD7793_FLAG_HAS_BUFFER,
654 	},
655 	[ID_AD7795] = {
656 		.id = AD7795_ID,
657 		.channels = ad7795_channels,
658 		.num_channels = ARRAY_SIZE(ad7795_channels),
659 		.iio_info = &ad7793_info,
660 		.sample_freq_avail = ad7793_sample_freq_avail,
661 		.flags = AD7793_FLAG_HAS_CLKSEL |
662 			AD7793_FLAG_HAS_REFSEL |
663 			AD7793_FLAG_HAS_VBIAS |
664 			AD7793_HAS_EXITATION_CURRENT |
665 			AD7793_FLAG_HAS_GAIN |
666 			AD7793_FLAG_HAS_BUFFER,
667 	},
668 	[ID_AD7796] = {
669 		.id = AD7796_ID,
670 		.channels = ad7796_channels,
671 		.num_channels = ARRAY_SIZE(ad7796_channels),
672 		.iio_info = &ad7797_info,
673 		.sample_freq_avail = ad7797_sample_freq_avail,
674 		.flags = AD7793_FLAG_HAS_CLKSEL,
675 	},
676 	[ID_AD7797] = {
677 		.id = AD7797_ID,
678 		.channels = ad7797_channels,
679 		.num_channels = ARRAY_SIZE(ad7797_channels),
680 		.iio_info = &ad7797_info,
681 		.sample_freq_avail = ad7797_sample_freq_avail,
682 		.flags = AD7793_FLAG_HAS_CLKSEL,
683 	},
684 	[ID_AD7798] = {
685 		.id = AD7798_ID,
686 		.channels = ad7798_channels,
687 		.num_channels = ARRAY_SIZE(ad7798_channels),
688 		.iio_info = &ad7793_info,
689 		.sample_freq_avail = ad7793_sample_freq_avail,
690 		.flags = AD7793_FLAG_HAS_GAIN |
691 			AD7793_FLAG_HAS_BUFFER,
692 	},
693 	[ID_AD7799] = {
694 		.id = AD7799_ID,
695 		.channels = ad7799_channels,
696 		.num_channels = ARRAY_SIZE(ad7799_channels),
697 		.iio_info = &ad7793_info,
698 		.sample_freq_avail = ad7793_sample_freq_avail,
699 		.flags = AD7793_FLAG_HAS_GAIN |
700 			AD7793_FLAG_HAS_BUFFER,
701 	},
702 };
703 
704 static int ad7793_probe(struct spi_device *spi)
705 {
706 	const struct ad7793_platform_data *pdata = spi->dev.platform_data;
707 	struct ad7793_state *st;
708 	struct iio_dev *indio_dev;
709 	int ret, vref_mv = 0;
710 
711 	if (!pdata) {
712 		dev_err(&spi->dev, "no platform data?\n");
713 		return -ENODEV;
714 	}
715 
716 	if (!spi->irq) {
717 		dev_err(&spi->dev, "no IRQ?\n");
718 		return -ENODEV;
719 	}
720 
721 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
722 	if (indio_dev == NULL)
723 		return -ENOMEM;
724 
725 	st = iio_priv(indio_dev);
726 
727 	ad_sd_init(&st->sd, indio_dev, spi, &ad7793_sigma_delta_info);
728 
729 	if (pdata->refsel != AD7793_REFSEL_INTERNAL) {
730 		st->reg = devm_regulator_get(&spi->dev, "refin");
731 		if (IS_ERR(st->reg))
732 			return PTR_ERR(st->reg);
733 
734 		ret = regulator_enable(st->reg);
735 		if (ret)
736 			return ret;
737 
738 		vref_mv = regulator_get_voltage(st->reg);
739 		if (vref_mv < 0) {
740 			ret = vref_mv;
741 			goto error_disable_reg;
742 		}
743 
744 		vref_mv /= 1000;
745 	} else {
746 		vref_mv = 1170; /* Build-in ref */
747 	}
748 
749 	st->chip_info =
750 		&ad7793_chip_info_tbl[spi_get_device_id(spi)->driver_data];
751 
752 	spi_set_drvdata(spi, indio_dev);
753 
754 	indio_dev->dev.parent = &spi->dev;
755 	indio_dev->dev.of_node = spi->dev.of_node;
756 	indio_dev->name = spi_get_device_id(spi)->name;
757 	indio_dev->modes = INDIO_DIRECT_MODE;
758 	indio_dev->channels = st->chip_info->channels;
759 	indio_dev->num_channels = st->chip_info->num_channels;
760 	indio_dev->info = st->chip_info->iio_info;
761 
762 	ret = ad_sd_setup_buffer_and_trigger(indio_dev);
763 	if (ret)
764 		goto error_disable_reg;
765 
766 	ret = ad7793_setup(indio_dev, pdata, vref_mv);
767 	if (ret)
768 		goto error_remove_trigger;
769 
770 	ret = iio_device_register(indio_dev);
771 	if (ret)
772 		goto error_remove_trigger;
773 
774 	return 0;
775 
776 error_remove_trigger:
777 	ad_sd_cleanup_buffer_and_trigger(indio_dev);
778 error_disable_reg:
779 	if (pdata->refsel != AD7793_REFSEL_INTERNAL)
780 		regulator_disable(st->reg);
781 
782 	return ret;
783 }
784 
785 static int ad7793_remove(struct spi_device *spi)
786 {
787 	const struct ad7793_platform_data *pdata = spi->dev.platform_data;
788 	struct iio_dev *indio_dev = spi_get_drvdata(spi);
789 	struct ad7793_state *st = iio_priv(indio_dev);
790 
791 	iio_device_unregister(indio_dev);
792 	ad_sd_cleanup_buffer_and_trigger(indio_dev);
793 
794 	if (pdata->refsel != AD7793_REFSEL_INTERNAL)
795 		regulator_disable(st->reg);
796 
797 	return 0;
798 }
799 
800 static const struct spi_device_id ad7793_id[] = {
801 	{"ad7785", ID_AD7785},
802 	{"ad7792", ID_AD7792},
803 	{"ad7793", ID_AD7793},
804 	{"ad7794", ID_AD7794},
805 	{"ad7795", ID_AD7795},
806 	{"ad7796", ID_AD7796},
807 	{"ad7797", ID_AD7797},
808 	{"ad7798", ID_AD7798},
809 	{"ad7799", ID_AD7799},
810 	{}
811 };
812 MODULE_DEVICE_TABLE(spi, ad7793_id);
813 
814 static struct spi_driver ad7793_driver = {
815 	.driver = {
816 		.name	= "ad7793",
817 	},
818 	.probe		= ad7793_probe,
819 	.remove		= ad7793_remove,
820 	.id_table	= ad7793_id,
821 };
822 module_spi_driver(ad7793_driver);
823 
824 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
825 MODULE_DESCRIPTION("Analog Devices AD7793 and similar ADCs");
826 MODULE_LICENSE("GPL v2");
827