xref: /openbmc/linux/drivers/iio/adc/ad7793.c (revision d2574c33)
1 /*
2  * AD7785/AD7792/AD7793/AD7794/AD7795 SPI ADC driver
3  *
4  * Copyright 2011-2012 Analog Devices Inc.
5  *
6  * Licensed under the GPL-2.
7  */
8 
9 #include <linux/interrupt.h>
10 #include <linux/device.h>
11 #include <linux/kernel.h>
12 #include <linux/slab.h>
13 #include <linux/sysfs.h>
14 #include <linux/spi/spi.h>
15 #include <linux/regulator/consumer.h>
16 #include <linux/err.h>
17 #include <linux/sched.h>
18 #include <linux/delay.h>
19 #include <linux/module.h>
20 
21 #include <linux/iio/iio.h>
22 #include <linux/iio/sysfs.h>
23 #include <linux/iio/buffer.h>
24 #include <linux/iio/trigger.h>
25 #include <linux/iio/trigger_consumer.h>
26 #include <linux/iio/triggered_buffer.h>
27 #include <linux/iio/adc/ad_sigma_delta.h>
28 #include <linux/platform_data/ad7793.h>
29 
30 /* Registers */
31 #define AD7793_REG_COMM		0 /* Communications Register (WO, 8-bit) */
32 #define AD7793_REG_STAT		0 /* Status Register	     (RO, 8-bit) */
33 #define AD7793_REG_MODE		1 /* Mode Register	     (RW, 16-bit */
34 #define AD7793_REG_CONF		2 /* Configuration Register  (RW, 16-bit) */
35 #define AD7793_REG_DATA		3 /* Data Register	     (RO, 16-/24-bit) */
36 #define AD7793_REG_ID		4 /* ID Register	     (RO, 8-bit) */
37 #define AD7793_REG_IO		5 /* IO Register	     (RO, 8-bit) */
38 #define AD7793_REG_OFFSET	6 /* Offset Register	     (RW, 16-bit
39 				   * (AD7792)/24-bit (AD7793)) */
40 #define AD7793_REG_FULLSALE	7 /* Full-Scale Register
41 				   * (RW, 16-bit (AD7792)/24-bit (AD7793)) */
42 
43 /* Communications Register Bit Designations (AD7793_REG_COMM) */
44 #define AD7793_COMM_WEN		(1 << 7) /* Write Enable */
45 #define AD7793_COMM_WRITE	(0 << 6) /* Write Operation */
46 #define AD7793_COMM_READ	(1 << 6) /* Read Operation */
47 #define AD7793_COMM_ADDR(x)	(((x) & 0x7) << 3) /* Register Address */
48 #define AD7793_COMM_CREAD	(1 << 2) /* Continuous Read of Data Register */
49 
50 /* Status Register Bit Designations (AD7793_REG_STAT) */
51 #define AD7793_STAT_RDY		(1 << 7) /* Ready */
52 #define AD7793_STAT_ERR		(1 << 6) /* Error (Overrange, Underrange) */
53 #define AD7793_STAT_CH3		(1 << 2) /* Channel 3 */
54 #define AD7793_STAT_CH2		(1 << 1) /* Channel 2 */
55 #define AD7793_STAT_CH1		(1 << 0) /* Channel 1 */
56 
57 /* Mode Register Bit Designations (AD7793_REG_MODE) */
58 #define AD7793_MODE_SEL(x)	(((x) & 0x7) << 13) /* Operation Mode Select */
59 #define AD7793_MODE_SEL_MASK	(0x7 << 13) /* Operation Mode Select mask */
60 #define AD7793_MODE_CLKSRC(x)	(((x) & 0x3) << 6) /* ADC Clock Source Select */
61 #define AD7793_MODE_RATE(x)	((x) & 0xF) /* Filter Update Rate Select */
62 
63 #define AD7793_MODE_CONT		0 /* Continuous Conversion Mode */
64 #define AD7793_MODE_SINGLE		1 /* Single Conversion Mode */
65 #define AD7793_MODE_IDLE		2 /* Idle Mode */
66 #define AD7793_MODE_PWRDN		3 /* Power-Down Mode */
67 #define AD7793_MODE_CAL_INT_ZERO	4 /* Internal Zero-Scale Calibration */
68 #define AD7793_MODE_CAL_INT_FULL	5 /* Internal Full-Scale Calibration */
69 #define AD7793_MODE_CAL_SYS_ZERO	6 /* System Zero-Scale Calibration */
70 #define AD7793_MODE_CAL_SYS_FULL	7 /* System Full-Scale Calibration */
71 
72 #define AD7793_CLK_INT		0 /* Internal 64 kHz Clock not
73 				   * available at the CLK pin */
74 #define AD7793_CLK_INT_CO	1 /* Internal 64 kHz Clock available
75 				   * at the CLK pin */
76 #define AD7793_CLK_EXT		2 /* External 64 kHz Clock */
77 #define AD7793_CLK_EXT_DIV2	3 /* External Clock divided by 2 */
78 
79 /* Configuration Register Bit Designations (AD7793_REG_CONF) */
80 #define AD7793_CONF_VBIAS(x)	(((x) & 0x3) << 14) /* Bias Voltage
81 						     * Generator Enable */
82 #define AD7793_CONF_BO_EN	(1 << 13) /* Burnout Current Enable */
83 #define AD7793_CONF_UNIPOLAR	(1 << 12) /* Unipolar/Bipolar Enable */
84 #define AD7793_CONF_BOOST	(1 << 11) /* Boost Enable */
85 #define AD7793_CONF_GAIN(x)	(((x) & 0x7) << 8) /* Gain Select */
86 #define AD7793_CONF_REFSEL(x)	((x) << 6) /* INT/EXT Reference Select */
87 #define AD7793_CONF_BUF		(1 << 4) /* Buffered Mode Enable */
88 #define AD7793_CONF_CHAN(x)	((x) & 0xf) /* Channel select */
89 #define AD7793_CONF_CHAN_MASK	0xf /* Channel select mask */
90 
91 #define AD7793_CH_AIN1P_AIN1M	0 /* AIN1(+) - AIN1(-) */
92 #define AD7793_CH_AIN2P_AIN2M	1 /* AIN2(+) - AIN2(-) */
93 #define AD7793_CH_AIN3P_AIN3M	2 /* AIN3(+) - AIN3(-) */
94 #define AD7793_CH_AIN1M_AIN1M	3 /* AIN1(-) - AIN1(-) */
95 #define AD7793_CH_TEMP		6 /* Temp Sensor */
96 #define AD7793_CH_AVDD_MONITOR	7 /* AVDD Monitor */
97 
98 #define AD7795_CH_AIN4P_AIN4M	4 /* AIN4(+) - AIN4(-) */
99 #define AD7795_CH_AIN5P_AIN5M	5 /* AIN5(+) - AIN5(-) */
100 #define AD7795_CH_AIN6P_AIN6M	6 /* AIN6(+) - AIN6(-) */
101 #define AD7795_CH_AIN1M_AIN1M	8 /* AIN1(-) - AIN1(-) */
102 
103 /* ID Register Bit Designations (AD7793_REG_ID) */
104 #define AD7785_ID		0x3
105 #define AD7792_ID		0xA
106 #define AD7793_ID		0xB
107 #define AD7794_ID		0xF
108 #define AD7795_ID		0xF
109 #define AD7796_ID		0xA
110 #define AD7797_ID		0xB
111 #define AD7798_ID		0x8
112 #define AD7799_ID		0x9
113 #define AD7793_ID_MASK		0xF
114 
115 /* IO (Excitation Current Sources) Register Bit Designations (AD7793_REG_IO) */
116 #define AD7793_IO_IEXC1_IOUT1_IEXC2_IOUT2	0 /* IEXC1 connect to IOUT1,
117 						   * IEXC2 connect to IOUT2 */
118 #define AD7793_IO_IEXC1_IOUT2_IEXC2_IOUT1	1 /* IEXC1 connect to IOUT2,
119 						   * IEXC2 connect to IOUT1 */
120 #define AD7793_IO_IEXC1_IEXC2_IOUT1		2 /* Both current sources
121 						   * IEXC1,2 connect to IOUT1 */
122 #define AD7793_IO_IEXC1_IEXC2_IOUT2		3 /* Both current sources
123 						   * IEXC1,2 connect to IOUT2 */
124 
125 #define AD7793_IO_IXCEN_10uA	(1 << 0) /* Excitation Current 10uA */
126 #define AD7793_IO_IXCEN_210uA	(2 << 0) /* Excitation Current 210uA */
127 #define AD7793_IO_IXCEN_1mA	(3 << 0) /* Excitation Current 1mA */
128 
129 /* NOTE:
130  * The AD7792/AD7793 features a dual use data out ready DOUT/RDY output.
131  * In order to avoid contentions on the SPI bus, it's therefore necessary
132  * to use spi bus locking.
133  *
134  * The DOUT/RDY output must also be wired to an interrupt capable GPIO.
135  */
136 
137 #define AD7793_FLAG_HAS_CLKSEL		BIT(0)
138 #define AD7793_FLAG_HAS_REFSEL		BIT(1)
139 #define AD7793_FLAG_HAS_VBIAS		BIT(2)
140 #define AD7793_HAS_EXITATION_CURRENT	BIT(3)
141 #define AD7793_FLAG_HAS_GAIN		BIT(4)
142 #define AD7793_FLAG_HAS_BUFFER		BIT(5)
143 
144 struct ad7793_chip_info {
145 	unsigned int id;
146 	const struct iio_chan_spec *channels;
147 	unsigned int num_channels;
148 	unsigned int flags;
149 
150 	const struct iio_info *iio_info;
151 	const u16 *sample_freq_avail;
152 };
153 
154 struct ad7793_state {
155 	const struct ad7793_chip_info	*chip_info;
156 	struct regulator		*reg;
157 	u16				int_vref_mv;
158 	u16				mode;
159 	u16				conf;
160 	u32				scale_avail[8][2];
161 
162 	struct ad_sigma_delta		sd;
163 
164 };
165 
166 enum ad7793_supported_device_ids {
167 	ID_AD7785,
168 	ID_AD7792,
169 	ID_AD7793,
170 	ID_AD7794,
171 	ID_AD7795,
172 	ID_AD7796,
173 	ID_AD7797,
174 	ID_AD7798,
175 	ID_AD7799,
176 };
177 
178 static struct ad7793_state *ad_sigma_delta_to_ad7793(struct ad_sigma_delta *sd)
179 {
180 	return container_of(sd, struct ad7793_state, sd);
181 }
182 
183 static int ad7793_set_channel(struct ad_sigma_delta *sd, unsigned int channel)
184 {
185 	struct ad7793_state *st = ad_sigma_delta_to_ad7793(sd);
186 
187 	st->conf &= ~AD7793_CONF_CHAN_MASK;
188 	st->conf |= AD7793_CONF_CHAN(channel);
189 
190 	return ad_sd_write_reg(&st->sd, AD7793_REG_CONF, 2, st->conf);
191 }
192 
193 static int ad7793_set_mode(struct ad_sigma_delta *sd,
194 			   enum ad_sigma_delta_mode mode)
195 {
196 	struct ad7793_state *st = ad_sigma_delta_to_ad7793(sd);
197 
198 	st->mode &= ~AD7793_MODE_SEL_MASK;
199 	st->mode |= AD7793_MODE_SEL(mode);
200 
201 	return ad_sd_write_reg(&st->sd, AD7793_REG_MODE, 2, st->mode);
202 }
203 
204 static const struct ad_sigma_delta_info ad7793_sigma_delta_info = {
205 	.set_channel = ad7793_set_channel,
206 	.set_mode = ad7793_set_mode,
207 	.has_registers = true,
208 	.addr_shift = 3,
209 	.read_mask = BIT(6),
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 ssize_t ad7793_show_scale_available(struct device *dev,
358 			struct device_attribute *attr, char *buf)
359 {
360 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
361 	struct ad7793_state *st = iio_priv(indio_dev);
362 	int i, len = 0;
363 
364 	for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++)
365 		len += sprintf(buf + len, "%d.%09u ", st->scale_avail[i][0],
366 			       st->scale_avail[i][1]);
367 
368 	len += sprintf(buf + len, "\n");
369 
370 	return len;
371 }
372 
373 static IIO_DEVICE_ATTR_NAMED(in_m_in_scale_available,
374 		in_voltage-voltage_scale_available, S_IRUGO,
375 		ad7793_show_scale_available, NULL, 0);
376 
377 static struct attribute *ad7793_attributes[] = {
378 	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
379 	&iio_dev_attr_in_m_in_scale_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 	.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 = &ad7793_attribute_group,
546 	.validate_trigger = ad_sd_validate_trigger,
547 };
548 
549 #define DECLARE_AD7793_CHANNELS(_name, _b, _sb, _s) \
550 const struct iio_chan_spec _name##_channels[] = { \
551 	AD_SD_DIFF_CHANNEL(0, 0, 0, AD7793_CH_AIN1P_AIN1M, (_b), (_sb), (_s)), \
552 	AD_SD_DIFF_CHANNEL(1, 1, 1, AD7793_CH_AIN2P_AIN2M, (_b), (_sb), (_s)), \
553 	AD_SD_DIFF_CHANNEL(2, 2, 2, AD7793_CH_AIN3P_AIN3M, (_b), (_sb), (_s)), \
554 	AD_SD_SHORTED_CHANNEL(3, 0, AD7793_CH_AIN1M_AIN1M, (_b), (_sb), (_s)), \
555 	AD_SD_TEMP_CHANNEL(4, AD7793_CH_TEMP, (_b), (_sb), (_s)), \
556 	AD_SD_SUPPLY_CHANNEL(5, 3, AD7793_CH_AVDD_MONITOR, (_b), (_sb), (_s)), \
557 	IIO_CHAN_SOFT_TIMESTAMP(6), \
558 }
559 
560 #define DECLARE_AD7795_CHANNELS(_name, _b, _sb) \
561 const struct iio_chan_spec _name##_channels[] = { \
562 	AD_SD_DIFF_CHANNEL(0, 0, 0, AD7793_CH_AIN1P_AIN1M, (_b), (_sb), 0), \
563 	AD_SD_DIFF_CHANNEL(1, 1, 1, AD7793_CH_AIN2P_AIN2M, (_b), (_sb), 0), \
564 	AD_SD_DIFF_CHANNEL(2, 2, 2, AD7793_CH_AIN3P_AIN3M, (_b), (_sb), 0), \
565 	AD_SD_DIFF_CHANNEL(3, 3, 3, AD7795_CH_AIN4P_AIN4M, (_b), (_sb), 0), \
566 	AD_SD_DIFF_CHANNEL(4, 4, 4, AD7795_CH_AIN5P_AIN5M, (_b), (_sb), 0), \
567 	AD_SD_DIFF_CHANNEL(5, 5, 5, AD7795_CH_AIN6P_AIN6M, (_b), (_sb), 0), \
568 	AD_SD_SHORTED_CHANNEL(6, 0, AD7795_CH_AIN1M_AIN1M, (_b), (_sb), 0), \
569 	AD_SD_TEMP_CHANNEL(7, AD7793_CH_TEMP, (_b), (_sb), 0), \
570 	AD_SD_SUPPLY_CHANNEL(8, 3, AD7793_CH_AVDD_MONITOR, (_b), (_sb), 0), \
571 	IIO_CHAN_SOFT_TIMESTAMP(9), \
572 }
573 
574 #define DECLARE_AD7797_CHANNELS(_name, _b, _sb) \
575 const struct iio_chan_spec _name##_channels[] = { \
576 	AD_SD_DIFF_CHANNEL(0, 0, 0, AD7793_CH_AIN1P_AIN1M, (_b), (_sb), 0), \
577 	AD_SD_SHORTED_CHANNEL(1, 0, AD7793_CH_AIN1M_AIN1M, (_b), (_sb), 0), \
578 	AD_SD_TEMP_CHANNEL(2, AD7793_CH_TEMP, (_b), (_sb), 0), \
579 	AD_SD_SUPPLY_CHANNEL(3, 3, AD7793_CH_AVDD_MONITOR, (_b), (_sb), 0), \
580 	IIO_CHAN_SOFT_TIMESTAMP(4), \
581 }
582 
583 #define DECLARE_AD7799_CHANNELS(_name, _b, _sb) \
584 const struct iio_chan_spec _name##_channels[] = { \
585 	AD_SD_DIFF_CHANNEL(0, 0, 0, AD7793_CH_AIN1P_AIN1M, (_b), (_sb), 0), \
586 	AD_SD_DIFF_CHANNEL(1, 1, 1, AD7793_CH_AIN2P_AIN2M, (_b), (_sb), 0), \
587 	AD_SD_DIFF_CHANNEL(2, 2, 2, AD7793_CH_AIN3P_AIN3M, (_b), (_sb), 0), \
588 	AD_SD_SHORTED_CHANNEL(3, 0, AD7793_CH_AIN1M_AIN1M, (_b), (_sb), 0), \
589 	AD_SD_SUPPLY_CHANNEL(4, 3, AD7793_CH_AVDD_MONITOR, (_b), (_sb), 0), \
590 	IIO_CHAN_SOFT_TIMESTAMP(5), \
591 }
592 
593 static DECLARE_AD7793_CHANNELS(ad7785, 20, 32, 4);
594 static DECLARE_AD7793_CHANNELS(ad7792, 16, 32, 0);
595 static DECLARE_AD7793_CHANNELS(ad7793, 24, 32, 0);
596 static DECLARE_AD7795_CHANNELS(ad7794, 16, 32);
597 static DECLARE_AD7795_CHANNELS(ad7795, 24, 32);
598 static DECLARE_AD7797_CHANNELS(ad7796, 16, 16);
599 static DECLARE_AD7797_CHANNELS(ad7797, 24, 32);
600 static DECLARE_AD7799_CHANNELS(ad7798, 16, 16);
601 static DECLARE_AD7799_CHANNELS(ad7799, 24, 32);
602 
603 static const struct ad7793_chip_info ad7793_chip_info_tbl[] = {
604 	[ID_AD7785] = {
605 		.id = AD7785_ID,
606 		.channels = ad7785_channels,
607 		.num_channels = ARRAY_SIZE(ad7785_channels),
608 		.iio_info = &ad7793_info,
609 		.sample_freq_avail = ad7793_sample_freq_avail,
610 		.flags = AD7793_FLAG_HAS_CLKSEL |
611 			AD7793_FLAG_HAS_REFSEL |
612 			AD7793_FLAG_HAS_VBIAS |
613 			AD7793_HAS_EXITATION_CURRENT |
614 			AD7793_FLAG_HAS_GAIN |
615 			AD7793_FLAG_HAS_BUFFER,
616 	},
617 	[ID_AD7792] = {
618 		.id = AD7792_ID,
619 		.channels = ad7792_channels,
620 		.num_channels = ARRAY_SIZE(ad7792_channels),
621 		.iio_info = &ad7793_info,
622 		.sample_freq_avail = ad7793_sample_freq_avail,
623 		.flags = AD7793_FLAG_HAS_CLKSEL |
624 			AD7793_FLAG_HAS_REFSEL |
625 			AD7793_FLAG_HAS_VBIAS |
626 			AD7793_HAS_EXITATION_CURRENT |
627 			AD7793_FLAG_HAS_GAIN |
628 			AD7793_FLAG_HAS_BUFFER,
629 	},
630 	[ID_AD7793] = {
631 		.id = AD7793_ID,
632 		.channels = ad7793_channels,
633 		.num_channels = ARRAY_SIZE(ad7793_channels),
634 		.iio_info = &ad7793_info,
635 		.sample_freq_avail = ad7793_sample_freq_avail,
636 		.flags = AD7793_FLAG_HAS_CLKSEL |
637 			AD7793_FLAG_HAS_REFSEL |
638 			AD7793_FLAG_HAS_VBIAS |
639 			AD7793_HAS_EXITATION_CURRENT |
640 			AD7793_FLAG_HAS_GAIN |
641 			AD7793_FLAG_HAS_BUFFER,
642 	},
643 	[ID_AD7794] = {
644 		.id = AD7794_ID,
645 		.channels = ad7794_channels,
646 		.num_channels = ARRAY_SIZE(ad7794_channels),
647 		.iio_info = &ad7793_info,
648 		.sample_freq_avail = ad7793_sample_freq_avail,
649 		.flags = AD7793_FLAG_HAS_CLKSEL |
650 			AD7793_FLAG_HAS_REFSEL |
651 			AD7793_FLAG_HAS_VBIAS |
652 			AD7793_HAS_EXITATION_CURRENT |
653 			AD7793_FLAG_HAS_GAIN |
654 			AD7793_FLAG_HAS_BUFFER,
655 	},
656 	[ID_AD7795] = {
657 		.id = AD7795_ID,
658 		.channels = ad7795_channels,
659 		.num_channels = ARRAY_SIZE(ad7795_channels),
660 		.iio_info = &ad7793_info,
661 		.sample_freq_avail = ad7793_sample_freq_avail,
662 		.flags = AD7793_FLAG_HAS_CLKSEL |
663 			AD7793_FLAG_HAS_REFSEL |
664 			AD7793_FLAG_HAS_VBIAS |
665 			AD7793_HAS_EXITATION_CURRENT |
666 			AD7793_FLAG_HAS_GAIN |
667 			AD7793_FLAG_HAS_BUFFER,
668 	},
669 	[ID_AD7796] = {
670 		.id = AD7796_ID,
671 		.channels = ad7796_channels,
672 		.num_channels = ARRAY_SIZE(ad7796_channels),
673 		.iio_info = &ad7797_info,
674 		.sample_freq_avail = ad7797_sample_freq_avail,
675 		.flags = AD7793_FLAG_HAS_CLKSEL,
676 	},
677 	[ID_AD7797] = {
678 		.id = AD7797_ID,
679 		.channels = ad7797_channels,
680 		.num_channels = ARRAY_SIZE(ad7797_channels),
681 		.iio_info = &ad7797_info,
682 		.sample_freq_avail = ad7797_sample_freq_avail,
683 		.flags = AD7793_FLAG_HAS_CLKSEL,
684 	},
685 	[ID_AD7798] = {
686 		.id = AD7798_ID,
687 		.channels = ad7798_channels,
688 		.num_channels = ARRAY_SIZE(ad7798_channels),
689 		.iio_info = &ad7793_info,
690 		.sample_freq_avail = ad7793_sample_freq_avail,
691 		.flags = AD7793_FLAG_HAS_GAIN |
692 			AD7793_FLAG_HAS_BUFFER,
693 	},
694 	[ID_AD7799] = {
695 		.id = AD7799_ID,
696 		.channels = ad7799_channels,
697 		.num_channels = ARRAY_SIZE(ad7799_channels),
698 		.iio_info = &ad7793_info,
699 		.sample_freq_avail = ad7793_sample_freq_avail,
700 		.flags = AD7793_FLAG_HAS_GAIN |
701 			AD7793_FLAG_HAS_BUFFER,
702 	},
703 };
704 
705 static int ad7793_probe(struct spi_device *spi)
706 {
707 	const struct ad7793_platform_data *pdata = spi->dev.platform_data;
708 	struct ad7793_state *st;
709 	struct iio_dev *indio_dev;
710 	int ret, vref_mv = 0;
711 
712 	if (!pdata) {
713 		dev_err(&spi->dev, "no platform data?\n");
714 		return -ENODEV;
715 	}
716 
717 	if (!spi->irq) {
718 		dev_err(&spi->dev, "no IRQ?\n");
719 		return -ENODEV;
720 	}
721 
722 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
723 	if (indio_dev == NULL)
724 		return -ENOMEM;
725 
726 	st = iio_priv(indio_dev);
727 
728 	ad_sd_init(&st->sd, indio_dev, spi, &ad7793_sigma_delta_info);
729 
730 	if (pdata->refsel != AD7793_REFSEL_INTERNAL) {
731 		st->reg = devm_regulator_get(&spi->dev, "refin");
732 		if (IS_ERR(st->reg))
733 			return PTR_ERR(st->reg);
734 
735 		ret = regulator_enable(st->reg);
736 		if (ret)
737 			return ret;
738 
739 		vref_mv = regulator_get_voltage(st->reg);
740 		if (vref_mv < 0) {
741 			ret = vref_mv;
742 			goto error_disable_reg;
743 		}
744 
745 		vref_mv /= 1000;
746 	} else {
747 		vref_mv = 1170; /* Build-in ref */
748 	}
749 
750 	st->chip_info =
751 		&ad7793_chip_info_tbl[spi_get_device_id(spi)->driver_data];
752 
753 	spi_set_drvdata(spi, indio_dev);
754 
755 	indio_dev->dev.parent = &spi->dev;
756 	indio_dev->dev.of_node = spi->dev.of_node;
757 	indio_dev->name = spi_get_device_id(spi)->name;
758 	indio_dev->modes = INDIO_DIRECT_MODE;
759 	indio_dev->channels = st->chip_info->channels;
760 	indio_dev->num_channels = st->chip_info->num_channels;
761 	indio_dev->info = st->chip_info->iio_info;
762 
763 	ret = ad_sd_setup_buffer_and_trigger(indio_dev);
764 	if (ret)
765 		goto error_disable_reg;
766 
767 	ret = ad7793_setup(indio_dev, pdata, vref_mv);
768 	if (ret)
769 		goto error_remove_trigger;
770 
771 	ret = iio_device_register(indio_dev);
772 	if (ret)
773 		goto error_remove_trigger;
774 
775 	return 0;
776 
777 error_remove_trigger:
778 	ad_sd_cleanup_buffer_and_trigger(indio_dev);
779 error_disable_reg:
780 	if (pdata->refsel != AD7793_REFSEL_INTERNAL)
781 		regulator_disable(st->reg);
782 
783 	return ret;
784 }
785 
786 static int ad7793_remove(struct spi_device *spi)
787 {
788 	const struct ad7793_platform_data *pdata = spi->dev.platform_data;
789 	struct iio_dev *indio_dev = spi_get_drvdata(spi);
790 	struct ad7793_state *st = iio_priv(indio_dev);
791 
792 	iio_device_unregister(indio_dev);
793 	ad_sd_cleanup_buffer_and_trigger(indio_dev);
794 
795 	if (pdata->refsel != AD7793_REFSEL_INTERNAL)
796 		regulator_disable(st->reg);
797 
798 	return 0;
799 }
800 
801 static const struct spi_device_id ad7793_id[] = {
802 	{"ad7785", ID_AD7785},
803 	{"ad7792", ID_AD7792},
804 	{"ad7793", ID_AD7793},
805 	{"ad7794", ID_AD7794},
806 	{"ad7795", ID_AD7795},
807 	{"ad7796", ID_AD7796},
808 	{"ad7797", ID_AD7797},
809 	{"ad7798", ID_AD7798},
810 	{"ad7799", ID_AD7799},
811 	{}
812 };
813 MODULE_DEVICE_TABLE(spi, ad7793_id);
814 
815 static struct spi_driver ad7793_driver = {
816 	.driver = {
817 		.name	= "ad7793",
818 	},
819 	.probe		= ad7793_probe,
820 	.remove		= ad7793_remove,
821 	.id_table	= ad7793_id,
822 };
823 module_spi_driver(ad7793_driver);
824 
825 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
826 MODULE_DESCRIPTION("Analog Devices AD7793 and similar ADCs");
827 MODULE_LICENSE("GPL v2");
828