xref: /linux/drivers/iio/adc/ad7793.c (revision cb4eb6771c0f8fd1c52a8f6fdec7762fb087380a)
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 	u16				mode;
156 	u16				conf;
157 	u32				scale_avail[8][2];
158 
159 	struct ad_sigma_delta		sd;
160 
161 };
162 
163 enum ad7793_supported_device_ids {
164 	ID_AD7785,
165 	ID_AD7792,
166 	ID_AD7793,
167 	ID_AD7794,
168 	ID_AD7795,
169 	ID_AD7796,
170 	ID_AD7797,
171 	ID_AD7798,
172 	ID_AD7799,
173 };
174 
ad_sigma_delta_to_ad7793(struct ad_sigma_delta * sd)175 static struct ad7793_state *ad_sigma_delta_to_ad7793(struct ad_sigma_delta *sd)
176 {
177 	return container_of(sd, struct ad7793_state, sd);
178 }
179 
ad7793_set_channel(struct ad_sigma_delta * sd,unsigned int channel)180 static int ad7793_set_channel(struct ad_sigma_delta *sd, unsigned int channel)
181 {
182 	struct ad7793_state *st = ad_sigma_delta_to_ad7793(sd);
183 
184 	st->conf &= ~AD7793_CONF_CHAN_MASK;
185 	st->conf |= AD7793_CONF_CHAN(channel);
186 
187 	return ad_sd_write_reg(&st->sd, AD7793_REG_CONF, 2, st->conf);
188 }
189 
ad7793_set_mode(struct ad_sigma_delta * sd,enum ad_sigma_delta_mode mode)190 static int ad7793_set_mode(struct ad_sigma_delta *sd,
191 			   enum ad_sigma_delta_mode mode)
192 {
193 	struct ad7793_state *st = ad_sigma_delta_to_ad7793(sd);
194 
195 	st->mode &= ~AD7793_MODE_SEL_MASK;
196 	st->mode |= AD7793_MODE_SEL(mode);
197 
198 	return ad_sd_write_reg(&st->sd, AD7793_REG_MODE, 2, st->mode);
199 }
200 
201 static const struct ad_sigma_delta_info ad7793_sigma_delta_info = {
202 	.set_channel = ad7793_set_channel,
203 	.set_mode = ad7793_set_mode,
204 	.has_registers = true,
205 	.addr_shift = 3,
206 	.read_mask = BIT(6),
207 	.irq_flags = IRQF_TRIGGER_FALLING,
208 	.num_resetclks = 32,
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 
ad7793_calibrate_all(struct ad7793_state * st)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 
ad7793_check_platform_data(struct ad7793_state * st,const struct ad7793_platform_data * pdata)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 
ad7793_setup(struct iio_dev * indio_dev,const struct ad7793_platform_data * pdata,unsigned int vref_mv)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);
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 		ret = -ENODEV;
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 
ad7793_read_avail(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,const int ** vals,int * type,int * length,long mask)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 
ad7793_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long m)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 
__ad7793_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)464 static int __ad7793_write_raw(struct iio_dev *indio_dev,
465 			      struct iio_chan_spec const *chan,
466 			      int val, int val2, long mask)
467 {
468 	struct ad7793_state *st = iio_priv(indio_dev);
469 	int i;
470 	unsigned int tmp;
471 
472 	switch (mask) {
473 	case IIO_CHAN_INFO_SCALE:
474 		for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++) {
475 			if (val2 != st->scale_avail[i][1])
476 				continue;
477 
478 			tmp = st->conf;
479 			st->conf &= ~AD7793_CONF_GAIN(-1);
480 			st->conf |= AD7793_CONF_GAIN(i);
481 
482 			if (tmp == st->conf)
483 				return 0;
484 
485 			ad_sd_write_reg(&st->sd, AD7793_REG_CONF,
486 					sizeof(st->conf), st->conf);
487 			ad7793_calibrate_all(st);
488 
489 			return 0;
490 		}
491 		return -EINVAL;
492 	case IIO_CHAN_INFO_SAMP_FREQ:
493 		if (!val)
494 			return -EINVAL;
495 
496 		for (i = 0; i < 16; i++)
497 			if (val == st->chip_info->sample_freq_avail[i])
498 				break;
499 
500 		if (i == 16)
501 			return -EINVAL;
502 
503 		st->mode &= ~AD7793_MODE_RATE(-1);
504 		st->mode |= AD7793_MODE_RATE(i);
505 		ad_sd_write_reg(&st->sd, AD7793_REG_MODE, sizeof(st->mode),
506 				st->mode);
507 		return 0;
508 	default:
509 		return -EINVAL;
510 	}
511 }
512 
ad7793_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)513 static int ad7793_write_raw(struct iio_dev *indio_dev,
514 			    struct iio_chan_spec const *chan,
515 			    int val, int val2, long mask)
516 {
517 	int ret;
518 
519 	if (!iio_device_claim_direct(indio_dev))
520 		return -EBUSY;
521 
522 	ret = __ad7793_write_raw(indio_dev, chan, val, val2, mask);
523 
524 	iio_device_release_direct(indio_dev);
525 
526 	return ret;
527 }
528 
ad7793_write_raw_get_fmt(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,long mask)529 static int ad7793_write_raw_get_fmt(struct iio_dev *indio_dev,
530 			       struct iio_chan_spec const *chan,
531 			       long mask)
532 {
533 	return IIO_VAL_INT_PLUS_NANO;
534 }
535 
536 static const struct iio_info ad7793_info = {
537 	.read_raw = &ad7793_read_raw,
538 	.write_raw = &ad7793_write_raw,
539 	.write_raw_get_fmt = &ad7793_write_raw_get_fmt,
540 	.read_avail = ad7793_read_avail,
541 	.attrs = &ad7793_attribute_group,
542 	.validate_trigger = ad_sd_validate_trigger,
543 };
544 
545 static const struct iio_info ad7797_info = {
546 	.read_raw = &ad7793_read_raw,
547 	.write_raw = &ad7793_write_raw,
548 	.write_raw_get_fmt = &ad7793_write_raw_get_fmt,
549 	.attrs = &ad7797_attribute_group,
550 	.validate_trigger = ad_sd_validate_trigger,
551 };
552 
553 #define __AD7793_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
554 	_storagebits, _shift, _extend_name, _type, _mask_type_av, _mask_all) \
555 	{ \
556 		.type = (_type), \
557 		.differential = (_channel2 == -1 ? 0 : 1), \
558 		.indexed = 1, \
559 		.channel = (_channel1), \
560 		.channel2 = (_channel2), \
561 		.address = (_address), \
562 		.extend_name = (_extend_name), \
563 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
564 			BIT(IIO_CHAN_INFO_OFFSET), \
565 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
566 		.info_mask_shared_by_type_available = (_mask_type_av), \
567 		.info_mask_shared_by_all = _mask_all, \
568 		.scan_index = (_si), \
569 		.scan_type = { \
570 			.sign = 'u', \
571 			.realbits = (_bits), \
572 			.storagebits = (_storagebits), \
573 			.shift = (_shift), \
574 			.endianness = IIO_BE, \
575 		}, \
576 	}
577 
578 #define AD7793_DIFF_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
579 	_storagebits, _shift) \
580 	__AD7793_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
581 		_storagebits, _shift, NULL, IIO_VOLTAGE, \
582 		BIT(IIO_CHAN_INFO_SCALE), \
583 		BIT(IIO_CHAN_INFO_SAMP_FREQ))
584 
585 #define AD7793_SHORTED_CHANNEL(_si, _channel, _address, _bits, \
586 	_storagebits, _shift) \
587 	__AD7793_CHANNEL(_si, _channel, _channel, _address, _bits, \
588 		_storagebits, _shift, "shorted", IIO_VOLTAGE, \
589 		BIT(IIO_CHAN_INFO_SCALE), \
590 		BIT(IIO_CHAN_INFO_SAMP_FREQ))
591 
592 #define AD7793_TEMP_CHANNEL(_si, _address, _bits, _storagebits, _shift) \
593 	__AD7793_CHANNEL(_si, 0, -1, _address, _bits, \
594 		_storagebits, _shift, NULL, IIO_TEMP, \
595 		0, \
596 		BIT(IIO_CHAN_INFO_SAMP_FREQ))
597 
598 #define AD7793_SUPPLY_CHANNEL(_si, _channel, _address, _bits, _storagebits, \
599 	_shift) \
600 	__AD7793_CHANNEL(_si, _channel, -1, _address, _bits, \
601 		_storagebits, _shift, "supply", IIO_VOLTAGE, \
602 		0, \
603 		BIT(IIO_CHAN_INFO_SAMP_FREQ))
604 
605 #define AD7797_DIFF_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
606 	_storagebits, _shift) \
607 	__AD7793_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
608 		_storagebits, _shift, NULL, IIO_VOLTAGE, \
609 		0, \
610 		BIT(IIO_CHAN_INFO_SAMP_FREQ))
611 
612 #define AD7797_SHORTED_CHANNEL(_si, _channel, _address, _bits, \
613 	_storagebits, _shift) \
614 	__AD7793_CHANNEL(_si, _channel, _channel, _address, _bits, \
615 		_storagebits, _shift, "shorted", IIO_VOLTAGE, \
616 		0, \
617 		BIT(IIO_CHAN_INFO_SAMP_FREQ))
618 
619 #define DECLARE_AD7793_CHANNELS(_name, _b, _sb, _s) \
620 const struct iio_chan_spec _name##_channels[] = { \
621 	AD7793_DIFF_CHANNEL(0, 0, 0, AD7793_CH_AIN1P_AIN1M, (_b), (_sb), (_s)), \
622 	AD7793_DIFF_CHANNEL(1, 1, 1, AD7793_CH_AIN2P_AIN2M, (_b), (_sb), (_s)), \
623 	AD7793_DIFF_CHANNEL(2, 2, 2, AD7793_CH_AIN3P_AIN3M, (_b), (_sb), (_s)), \
624 	AD7793_SHORTED_CHANNEL(3, 0, AD7793_CH_AIN1M_AIN1M, (_b), (_sb), (_s)), \
625 	AD7793_TEMP_CHANNEL(4, AD7793_CH_TEMP, (_b), (_sb), (_s)), \
626 	AD7793_SUPPLY_CHANNEL(5, 3, AD7793_CH_AVDD_MONITOR, (_b), (_sb), (_s)), \
627 	IIO_CHAN_SOFT_TIMESTAMP(6), \
628 }
629 
630 #define DECLARE_AD7795_CHANNELS(_name, _b, _sb) \
631 const struct iio_chan_spec _name##_channels[] = { \
632 	AD7793_DIFF_CHANNEL(0, 0, 0, AD7793_CH_AIN1P_AIN1M, (_b), (_sb), 0), \
633 	AD7793_DIFF_CHANNEL(1, 1, 1, AD7793_CH_AIN2P_AIN2M, (_b), (_sb), 0), \
634 	AD7793_DIFF_CHANNEL(2, 2, 2, AD7793_CH_AIN3P_AIN3M, (_b), (_sb), 0), \
635 	AD7793_DIFF_CHANNEL(3, 3, 3, AD7795_CH_AIN4P_AIN4M, (_b), (_sb), 0), \
636 	AD7793_DIFF_CHANNEL(4, 4, 4, AD7795_CH_AIN5P_AIN5M, (_b), (_sb), 0), \
637 	AD7793_DIFF_CHANNEL(5, 5, 5, AD7795_CH_AIN6P_AIN6M, (_b), (_sb), 0), \
638 	AD7793_SHORTED_CHANNEL(6, 0, AD7795_CH_AIN1M_AIN1M, (_b), (_sb), 0), \
639 	AD7793_TEMP_CHANNEL(7, AD7793_CH_TEMP, (_b), (_sb), 0), \
640 	AD7793_SUPPLY_CHANNEL(8, 3, AD7793_CH_AVDD_MONITOR, (_b), (_sb), 0), \
641 	IIO_CHAN_SOFT_TIMESTAMP(9), \
642 }
643 
644 #define DECLARE_AD7797_CHANNELS(_name, _b, _sb) \
645 const struct iio_chan_spec _name##_channels[] = { \
646 	AD7797_DIFF_CHANNEL(0, 0, 0, AD7793_CH_AIN1P_AIN1M, (_b), (_sb), 0), \
647 	AD7797_SHORTED_CHANNEL(1, 0, AD7793_CH_AIN1M_AIN1M, (_b), (_sb), 0), \
648 	AD7793_TEMP_CHANNEL(2, AD7793_CH_TEMP, (_b), (_sb), 0), \
649 	AD7793_SUPPLY_CHANNEL(3, 3, AD7793_CH_AVDD_MONITOR, (_b), (_sb), 0), \
650 	IIO_CHAN_SOFT_TIMESTAMP(4), \
651 }
652 
653 #define DECLARE_AD7799_CHANNELS(_name, _b, _sb) \
654 const struct iio_chan_spec _name##_channels[] = { \
655 	AD7793_DIFF_CHANNEL(0, 0, 0, AD7793_CH_AIN1P_AIN1M, (_b), (_sb), 0), \
656 	AD7793_DIFF_CHANNEL(1, 1, 1, AD7793_CH_AIN2P_AIN2M, (_b), (_sb), 0), \
657 	AD7793_DIFF_CHANNEL(2, 2, 2, AD7793_CH_AIN3P_AIN3M, (_b), (_sb), 0), \
658 	AD7793_SHORTED_CHANNEL(3, 0, AD7793_CH_AIN1M_AIN1M, (_b), (_sb), 0), \
659 	AD7793_SUPPLY_CHANNEL(4, 3, AD7793_CH_AVDD_MONITOR, (_b), (_sb), 0), \
660 	IIO_CHAN_SOFT_TIMESTAMP(5), \
661 }
662 
663 static DECLARE_AD7793_CHANNELS(ad7785, 20, 32, 4);
664 static DECLARE_AD7793_CHANNELS(ad7792, 16, 32, 0);
665 static DECLARE_AD7793_CHANNELS(ad7793, 24, 32, 0);
666 static DECLARE_AD7795_CHANNELS(ad7794, 16, 32);
667 static DECLARE_AD7795_CHANNELS(ad7795, 24, 32);
668 static DECLARE_AD7797_CHANNELS(ad7796, 16, 16);
669 static DECLARE_AD7797_CHANNELS(ad7797, 24, 32);
670 static DECLARE_AD7799_CHANNELS(ad7798, 16, 16);
671 static DECLARE_AD7799_CHANNELS(ad7799, 24, 32);
672 
673 static const struct ad7793_chip_info ad7793_chip_info_tbl[] = {
674 	[ID_AD7785] = {
675 		.id = AD7785_ID,
676 		.channels = ad7785_channels,
677 		.num_channels = ARRAY_SIZE(ad7785_channels),
678 		.iio_info = &ad7793_info,
679 		.sample_freq_avail = ad7793_sample_freq_avail,
680 		.flags = AD7793_FLAG_HAS_CLKSEL |
681 			AD7793_FLAG_HAS_REFSEL |
682 			AD7793_FLAG_HAS_VBIAS |
683 			AD7793_HAS_EXITATION_CURRENT |
684 			AD7793_FLAG_HAS_GAIN |
685 			AD7793_FLAG_HAS_BUFFER,
686 	},
687 	[ID_AD7792] = {
688 		.id = AD7792_ID,
689 		.channels = ad7792_channels,
690 		.num_channels = ARRAY_SIZE(ad7792_channels),
691 		.iio_info = &ad7793_info,
692 		.sample_freq_avail = ad7793_sample_freq_avail,
693 		.flags = AD7793_FLAG_HAS_CLKSEL |
694 			AD7793_FLAG_HAS_REFSEL |
695 			AD7793_FLAG_HAS_VBIAS |
696 			AD7793_HAS_EXITATION_CURRENT |
697 			AD7793_FLAG_HAS_GAIN |
698 			AD7793_FLAG_HAS_BUFFER,
699 	},
700 	[ID_AD7793] = {
701 		.id = AD7793_ID,
702 		.channels = ad7793_channels,
703 		.num_channels = ARRAY_SIZE(ad7793_channels),
704 		.iio_info = &ad7793_info,
705 		.sample_freq_avail = ad7793_sample_freq_avail,
706 		.flags = AD7793_FLAG_HAS_CLKSEL |
707 			AD7793_FLAG_HAS_REFSEL |
708 			AD7793_FLAG_HAS_VBIAS |
709 			AD7793_HAS_EXITATION_CURRENT |
710 			AD7793_FLAG_HAS_GAIN |
711 			AD7793_FLAG_HAS_BUFFER,
712 	},
713 	[ID_AD7794] = {
714 		.id = AD7794_ID,
715 		.channels = ad7794_channels,
716 		.num_channels = ARRAY_SIZE(ad7794_channels),
717 		.iio_info = &ad7793_info,
718 		.sample_freq_avail = ad7793_sample_freq_avail,
719 		.flags = AD7793_FLAG_HAS_CLKSEL |
720 			AD7793_FLAG_HAS_REFSEL |
721 			AD7793_FLAG_HAS_VBIAS |
722 			AD7793_HAS_EXITATION_CURRENT |
723 			AD7793_FLAG_HAS_GAIN |
724 			AD7793_FLAG_HAS_BUFFER,
725 	},
726 	[ID_AD7795] = {
727 		.id = AD7795_ID,
728 		.channels = ad7795_channels,
729 		.num_channels = ARRAY_SIZE(ad7795_channels),
730 		.iio_info = &ad7793_info,
731 		.sample_freq_avail = ad7793_sample_freq_avail,
732 		.flags = AD7793_FLAG_HAS_CLKSEL |
733 			AD7793_FLAG_HAS_REFSEL |
734 			AD7793_FLAG_HAS_VBIAS |
735 			AD7793_HAS_EXITATION_CURRENT |
736 			AD7793_FLAG_HAS_GAIN |
737 			AD7793_FLAG_HAS_BUFFER,
738 	},
739 	[ID_AD7796] = {
740 		.id = AD7796_ID,
741 		.channels = ad7796_channels,
742 		.num_channels = ARRAY_SIZE(ad7796_channels),
743 		.iio_info = &ad7797_info,
744 		.sample_freq_avail = ad7797_sample_freq_avail,
745 		.flags = AD7793_FLAG_HAS_CLKSEL,
746 	},
747 	[ID_AD7797] = {
748 		.id = AD7797_ID,
749 		.channels = ad7797_channels,
750 		.num_channels = ARRAY_SIZE(ad7797_channels),
751 		.iio_info = &ad7797_info,
752 		.sample_freq_avail = ad7797_sample_freq_avail,
753 		.flags = AD7793_FLAG_HAS_CLKSEL,
754 	},
755 	[ID_AD7798] = {
756 		.id = AD7798_ID,
757 		.channels = ad7798_channels,
758 		.num_channels = ARRAY_SIZE(ad7798_channels),
759 		.iio_info = &ad7793_info,
760 		.sample_freq_avail = ad7793_sample_freq_avail,
761 		.flags = AD7793_FLAG_HAS_GAIN |
762 			AD7793_FLAG_HAS_BUFFER,
763 	},
764 	[ID_AD7799] = {
765 		.id = AD7799_ID,
766 		.channels = ad7799_channels,
767 		.num_channels = ARRAY_SIZE(ad7799_channels),
768 		.iio_info = &ad7793_info,
769 		.sample_freq_avail = ad7793_sample_freq_avail,
770 		.flags = AD7793_FLAG_HAS_GAIN |
771 			AD7793_FLAG_HAS_BUFFER,
772 	},
773 };
774 
ad7793_probe(struct spi_device * spi)775 static int ad7793_probe(struct spi_device *spi)
776 {
777 	const struct ad7793_platform_data *pdata = dev_get_platdata(&spi->dev);
778 	struct ad7793_state *st;
779 	struct iio_dev *indio_dev;
780 	int ret, vref_mv = 0;
781 
782 	if (!pdata) {
783 		dev_err(&spi->dev, "no platform data?\n");
784 		return -ENODEV;
785 	}
786 
787 	if (!spi->irq) {
788 		dev_err(&spi->dev, "no IRQ?\n");
789 		return -ENODEV;
790 	}
791 
792 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
793 	if (indio_dev == NULL)
794 		return -ENOMEM;
795 
796 	st = iio_priv(indio_dev);
797 
798 	ad_sd_init(&st->sd, indio_dev, spi, &ad7793_sigma_delta_info);
799 
800 	if (pdata->refsel != AD7793_REFSEL_INTERNAL) {
801 		ret = devm_regulator_get_enable_read_voltage(&spi->dev, "refin");
802 		if (ret < 0)
803 			return ret;
804 
805 		vref_mv = ret / 1000;
806 	} else {
807 		vref_mv = 1170; /* Built-in ref */
808 	}
809 
810 	st->chip_info =
811 		&ad7793_chip_info_tbl[spi_get_device_id(spi)->driver_data];
812 
813 	indio_dev->name = spi_get_device_id(spi)->name;
814 	indio_dev->modes = INDIO_DIRECT_MODE;
815 	indio_dev->channels = st->chip_info->channels;
816 	indio_dev->num_channels = st->chip_info->num_channels;
817 	indio_dev->info = st->chip_info->iio_info;
818 
819 	ret = devm_ad_sd_setup_buffer_and_trigger(&spi->dev, indio_dev);
820 	if (ret)
821 		return ret;
822 
823 	ret = ad7793_setup(indio_dev, pdata, vref_mv);
824 	if (ret)
825 		return ret;
826 
827 	return devm_iio_device_register(&spi->dev, indio_dev);
828 }
829 
830 static const struct spi_device_id ad7793_id[] = {
831 	{ "ad7785", ID_AD7785 },
832 	{ "ad7792", ID_AD7792 },
833 	{ "ad7793", ID_AD7793 },
834 	{ "ad7794", ID_AD7794 },
835 	{ "ad7795", ID_AD7795 },
836 	{ "ad7796", ID_AD7796 },
837 	{ "ad7797", ID_AD7797 },
838 	{ "ad7798", ID_AD7798 },
839 	{ "ad7799", ID_AD7799 },
840 	{ }
841 };
842 MODULE_DEVICE_TABLE(spi, ad7793_id);
843 
844 static struct spi_driver ad7793_driver = {
845 	.driver = {
846 		.name	= "ad7793",
847 	},
848 	.probe		= ad7793_probe,
849 	.id_table	= ad7793_id,
850 };
851 module_spi_driver(ad7793_driver);
852 
853 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
854 MODULE_DESCRIPTION("Analog Devices AD7793 and similar ADCs");
855 MODULE_LICENSE("GPL v2");
856 MODULE_IMPORT_NS("IIO_AD_SIGMA_DELTA");
857