1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Support code for Analog Devices Sigma-Delta ADCs
4 *
5 * Copyright 2012 Analog Devices Inc.
6 * Author: Lars-Peter Clausen <lars@metafoo.de>
7 */
8
9#include <linux/align.h>
10#include <linux/interrupt.h>
11#include <linux/device.h>
12#include <linux/kernel.h>
13#include <linux/slab.h>
14#include <linux/spi/spi.h>
15#include <linux/err.h>
16#include <linux/module.h>
17
18#include <linux/iio/iio.h>
19#include <linux/iio/sysfs.h>
20#include <linux/iio/buffer.h>
21#include <linux/iio/trigger.h>
22#include <linux/iio/trigger_consumer.h>
23#include <linux/iio/triggered_buffer.h>
24#include <linux/iio/adc/ad_sigma_delta.h>
25
26#include <asm/unaligned.h>
27
28
29#define AD_SD_COMM_CHAN_MASK 0x3
30
31#define AD_SD_REG_COMM 0x00
32#define AD_SD_REG_DATA 0x03
33
34/**
35 * ad_sd_set_comm() - Set communications register
36 *
37 * @sigma_delta: The sigma delta device
38 * @comm: New value for the communications register
39 */
40void ad_sd_set_comm(struct ad_sigma_delta *sigma_delta, uint8_t comm)
41{
42 /* Some variants use the lower two bits of the communications register
43 * to select the channel */
44 sigma_delta->comm = comm & AD_SD_COMM_CHAN_MASK;
45}
46EXPORT_SYMBOL_NS_GPL(ad_sd_set_comm, IIO_AD_SIGMA_DELTA);
47
48/**
49 * ad_sd_write_reg() - Write a register
50 *
51 * @sigma_delta: The sigma delta device
52 * @reg: Address of the register
53 * @size: Size of the register (0-3)
54 * @val: Value to write to the register
55 *
56 * Returns 0 on success, an error code otherwise.
57 **/
58int ad_sd_write_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg,
59 unsigned int size, unsigned int val)
60{
61 uint8_t *data = sigma_delta->tx_buf;
62 struct spi_transfer t = {
63 .tx_buf = data,
64 .len = size + 1,
65 .cs_change = sigma_delta->keep_cs_asserted,
66 };
67 struct spi_message m;
68 int ret;
69
70 data[0] = (reg << sigma_delta->info->addr_shift) | sigma_delta->comm;
71
72 switch (size) {
73 case 3:
74 put_unaligned_be24(val, p: &data[1]);
75 break;
76 case 2:
77 put_unaligned_be16(val, p: &data[1]);
78 break;
79 case 1:
80 data[1] = val;
81 break;
82 case 0:
83 break;
84 default:
85 return -EINVAL;
86 }
87
88 spi_message_init(m: &m);
89 spi_message_add_tail(t: &t, m: &m);
90
91 if (sigma_delta->bus_locked)
92 ret = spi_sync_locked(spi: sigma_delta->spi, message: &m);
93 else
94 ret = spi_sync(spi: sigma_delta->spi, message: &m);
95
96 return ret;
97}
98EXPORT_SYMBOL_NS_GPL(ad_sd_write_reg, IIO_AD_SIGMA_DELTA);
99
100static int ad_sd_read_reg_raw(struct ad_sigma_delta *sigma_delta,
101 unsigned int reg, unsigned int size, uint8_t *val)
102{
103 uint8_t *data = sigma_delta->tx_buf;
104 int ret;
105 struct spi_transfer t[] = {
106 {
107 .tx_buf = data,
108 .len = 1,
109 }, {
110 .rx_buf = val,
111 .len = size,
112 .cs_change = sigma_delta->bus_locked,
113 },
114 };
115 struct spi_message m;
116
117 spi_message_init(m: &m);
118
119 if (sigma_delta->info->has_registers) {
120 data[0] = reg << sigma_delta->info->addr_shift;
121 data[0] |= sigma_delta->info->read_mask;
122 data[0] |= sigma_delta->comm;
123 spi_message_add_tail(t: &t[0], m: &m);
124 }
125 spi_message_add_tail(t: &t[1], m: &m);
126
127 if (sigma_delta->bus_locked)
128 ret = spi_sync_locked(spi: sigma_delta->spi, message: &m);
129 else
130 ret = spi_sync(spi: sigma_delta->spi, message: &m);
131
132 return ret;
133}
134
135/**
136 * ad_sd_read_reg() - Read a register
137 *
138 * @sigma_delta: The sigma delta device
139 * @reg: Address of the register
140 * @size: Size of the register (1-4)
141 * @val: Read value
142 *
143 * Returns 0 on success, an error code otherwise.
144 **/
145int ad_sd_read_reg(struct ad_sigma_delta *sigma_delta,
146 unsigned int reg, unsigned int size, unsigned int *val)
147{
148 int ret;
149
150 ret = ad_sd_read_reg_raw(sigma_delta, reg, size, val: sigma_delta->rx_buf);
151 if (ret < 0)
152 goto out;
153
154 switch (size) {
155 case 4:
156 *val = get_unaligned_be32(p: sigma_delta->rx_buf);
157 break;
158 case 3:
159 *val = get_unaligned_be24(p: sigma_delta->rx_buf);
160 break;
161 case 2:
162 *val = get_unaligned_be16(p: sigma_delta->rx_buf);
163 break;
164 case 1:
165 *val = sigma_delta->rx_buf[0];
166 break;
167 default:
168 ret = -EINVAL;
169 break;
170 }
171
172out:
173 return ret;
174}
175EXPORT_SYMBOL_NS_GPL(ad_sd_read_reg, IIO_AD_SIGMA_DELTA);
176
177/**
178 * ad_sd_reset() - Reset the serial interface
179 *
180 * @sigma_delta: The sigma delta device
181 * @reset_length: Number of SCLKs with DIN = 1
182 *
183 * Returns 0 on success, an error code otherwise.
184 **/
185int ad_sd_reset(struct ad_sigma_delta *sigma_delta,
186 unsigned int reset_length)
187{
188 uint8_t *buf;
189 unsigned int size;
190 int ret;
191
192 size = DIV_ROUND_UP(reset_length, 8);
193 buf = kcalloc(n: size, size: sizeof(*buf), GFP_KERNEL);
194 if (!buf)
195 return -ENOMEM;
196
197 memset(buf, 0xff, size);
198 ret = spi_write(spi: sigma_delta->spi, buf, len: size);
199 kfree(objp: buf);
200
201 return ret;
202}
203EXPORT_SYMBOL_NS_GPL(ad_sd_reset, IIO_AD_SIGMA_DELTA);
204
205int ad_sd_calibrate(struct ad_sigma_delta *sigma_delta,
206 unsigned int mode, unsigned int channel)
207{
208 int ret;
209 unsigned long timeout;
210
211 ret = ad_sigma_delta_set_channel(sd: sigma_delta, channel);
212 if (ret)
213 return ret;
214
215 spi_bus_lock(ctlr: sigma_delta->spi->controller);
216 sigma_delta->bus_locked = true;
217 sigma_delta->keep_cs_asserted = true;
218 reinit_completion(x: &sigma_delta->completion);
219
220 ret = ad_sigma_delta_set_mode(sd: sigma_delta, mode);
221 if (ret < 0)
222 goto out;
223
224 sigma_delta->irq_dis = false;
225 enable_irq(irq: sigma_delta->spi->irq);
226 timeout = wait_for_completion_timeout(x: &sigma_delta->completion, timeout: 2 * HZ);
227 if (timeout == 0) {
228 sigma_delta->irq_dis = true;
229 disable_irq_nosync(irq: sigma_delta->spi->irq);
230 ret = -EIO;
231 } else {
232 ret = 0;
233 }
234out:
235 sigma_delta->keep_cs_asserted = false;
236 ad_sigma_delta_set_mode(sd: sigma_delta, mode: AD_SD_MODE_IDLE);
237 sigma_delta->bus_locked = false;
238 spi_bus_unlock(ctlr: sigma_delta->spi->controller);
239
240 return ret;
241}
242EXPORT_SYMBOL_NS_GPL(ad_sd_calibrate, IIO_AD_SIGMA_DELTA);
243
244/**
245 * ad_sd_calibrate_all() - Performs channel calibration
246 * @sigma_delta: The sigma delta device
247 * @cb: Array of channels and calibration type to perform
248 * @n: Number of items in cb
249 *
250 * Returns 0 on success, an error code otherwise.
251 **/
252int ad_sd_calibrate_all(struct ad_sigma_delta *sigma_delta,
253 const struct ad_sd_calib_data *cb, unsigned int n)
254{
255 unsigned int i;
256 int ret;
257
258 for (i = 0; i < n; i++) {
259 ret = ad_sd_calibrate(sigma_delta, cb[i].mode, cb[i].channel);
260 if (ret)
261 return ret;
262 }
263
264 return 0;
265}
266EXPORT_SYMBOL_NS_GPL(ad_sd_calibrate_all, IIO_AD_SIGMA_DELTA);
267
268/**
269 * ad_sigma_delta_single_conversion() - Performs a single data conversion
270 * @indio_dev: The IIO device
271 * @chan: The conversion is done for this channel
272 * @val: Pointer to the location where to store the read value
273 *
274 * Returns: 0 on success, an error value otherwise.
275 */
276int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev,
277 const struct iio_chan_spec *chan, int *val)
278{
279 struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
280 unsigned int sample, raw_sample;
281 unsigned int data_reg;
282 int ret = 0;
283
284 ret = iio_device_claim_direct_mode(indio_dev);
285 if (ret)
286 return ret;
287
288 ad_sigma_delta_set_channel(sd: sigma_delta, channel: chan->address);
289
290 spi_bus_lock(ctlr: sigma_delta->spi->controller);
291 sigma_delta->bus_locked = true;
292 sigma_delta->keep_cs_asserted = true;
293 reinit_completion(x: &sigma_delta->completion);
294
295 ad_sigma_delta_set_mode(sd: sigma_delta, mode: AD_SD_MODE_SINGLE);
296
297 sigma_delta->irq_dis = false;
298 enable_irq(irq: sigma_delta->spi->irq);
299 ret = wait_for_completion_interruptible_timeout(
300 x: &sigma_delta->completion, HZ);
301
302 if (ret == 0)
303 ret = -EIO;
304 if (ret < 0)
305 goto out;
306
307 if (sigma_delta->info->data_reg != 0)
308 data_reg = sigma_delta->info->data_reg;
309 else
310 data_reg = AD_SD_REG_DATA;
311
312 ret = ad_sd_read_reg(sigma_delta, data_reg,
313 DIV_ROUND_UP(chan->scan_type.realbits + chan->scan_type.shift, 8),
314 &raw_sample);
315
316out:
317 if (!sigma_delta->irq_dis) {
318 disable_irq_nosync(irq: sigma_delta->spi->irq);
319 sigma_delta->irq_dis = true;
320 }
321
322 sigma_delta->keep_cs_asserted = false;
323 ad_sigma_delta_set_mode(sd: sigma_delta, mode: AD_SD_MODE_IDLE);
324 sigma_delta->bus_locked = false;
325 spi_bus_unlock(ctlr: sigma_delta->spi->controller);
326 iio_device_release_direct_mode(indio_dev);
327
328 if (ret)
329 return ret;
330
331 sample = raw_sample >> chan->scan_type.shift;
332 sample &= (1 << chan->scan_type.realbits) - 1;
333 *val = sample;
334
335 ret = ad_sigma_delta_postprocess_sample(sd: sigma_delta, raw_sample);
336 if (ret)
337 return ret;
338
339 return IIO_VAL_INT;
340}
341EXPORT_SYMBOL_NS_GPL(ad_sigma_delta_single_conversion, IIO_AD_SIGMA_DELTA);
342
343static int ad_sd_buffer_postenable(struct iio_dev *indio_dev)
344{
345 struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
346 unsigned int i, slot, samples_buf_size;
347 unsigned int channel;
348 uint8_t *samples_buf;
349 int ret;
350
351 if (sigma_delta->num_slots == 1) {
352 channel = find_first_bit(addr: indio_dev->active_scan_mask,
353 size: indio_dev->masklength);
354 ret = ad_sigma_delta_set_channel(sd: sigma_delta,
355 channel: indio_dev->channels[channel].address);
356 if (ret)
357 return ret;
358 slot = 1;
359 } else {
360 /*
361 * At this point update_scan_mode already enabled the required channels.
362 * For sigma-delta sequencer drivers with multiple slots, an update_scan_mode
363 * implementation is mandatory.
364 */
365 slot = 0;
366 for_each_set_bit(i, indio_dev->active_scan_mask, indio_dev->masklength) {
367 sigma_delta->slots[slot] = indio_dev->channels[i].address;
368 slot++;
369 }
370 }
371
372 sigma_delta->active_slots = slot;
373 sigma_delta->current_slot = 0;
374
375 if (sigma_delta->active_slots > 1) {
376 ret = ad_sigma_delta_append_status(sd: sigma_delta, append: true);
377 if (ret)
378 return ret;
379 }
380
381 samples_buf_size = ALIGN(slot * indio_dev->channels[0].scan_type.storagebits, 8);
382 samples_buf_size += sizeof(int64_t);
383 samples_buf = devm_krealloc(dev: &sigma_delta->spi->dev, ptr: sigma_delta->samples_buf,
384 size: samples_buf_size, GFP_KERNEL);
385 if (!samples_buf)
386 return -ENOMEM;
387
388 sigma_delta->samples_buf = samples_buf;
389
390 spi_bus_lock(ctlr: sigma_delta->spi->controller);
391 sigma_delta->bus_locked = true;
392 sigma_delta->keep_cs_asserted = true;
393
394 ret = ad_sigma_delta_set_mode(sd: sigma_delta, mode: AD_SD_MODE_CONTINUOUS);
395 if (ret)
396 goto err_unlock;
397
398 sigma_delta->irq_dis = false;
399 enable_irq(irq: sigma_delta->spi->irq);
400
401 return 0;
402
403err_unlock:
404 spi_bus_unlock(ctlr: sigma_delta->spi->controller);
405
406 return ret;
407}
408
409static int ad_sd_buffer_postdisable(struct iio_dev *indio_dev)
410{
411 struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
412
413 reinit_completion(x: &sigma_delta->completion);
414 wait_for_completion_timeout(x: &sigma_delta->completion, HZ);
415
416 if (!sigma_delta->irq_dis) {
417 disable_irq_nosync(irq: sigma_delta->spi->irq);
418 sigma_delta->irq_dis = true;
419 }
420
421 sigma_delta->keep_cs_asserted = false;
422 ad_sigma_delta_set_mode(sd: sigma_delta, mode: AD_SD_MODE_IDLE);
423
424 if (sigma_delta->status_appended)
425 ad_sigma_delta_append_status(sd: sigma_delta, append: false);
426
427 ad_sigma_delta_disable_all(sd: sigma_delta);
428 sigma_delta->bus_locked = false;
429 return spi_bus_unlock(ctlr: sigma_delta->spi->controller);
430}
431
432static irqreturn_t ad_sd_trigger_handler(int irq, void *p)
433{
434 struct iio_poll_func *pf = p;
435 struct iio_dev *indio_dev = pf->indio_dev;
436 struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
437 uint8_t *data = sigma_delta->rx_buf;
438 unsigned int transfer_size;
439 unsigned int sample_size;
440 unsigned int sample_pos;
441 unsigned int status_pos;
442 unsigned int reg_size;
443 unsigned int data_reg;
444
445 reg_size = indio_dev->channels[0].scan_type.realbits +
446 indio_dev->channels[0].scan_type.shift;
447 reg_size = DIV_ROUND_UP(reg_size, 8);
448
449 if (sigma_delta->info->data_reg != 0)
450 data_reg = sigma_delta->info->data_reg;
451 else
452 data_reg = AD_SD_REG_DATA;
453
454 /* Status word will be appended to the sample during transfer */
455 if (sigma_delta->status_appended)
456 transfer_size = reg_size + 1;
457 else
458 transfer_size = reg_size;
459
460 switch (reg_size) {
461 case 4:
462 case 2:
463 case 1:
464 status_pos = reg_size;
465 ad_sd_read_reg_raw(sigma_delta, reg: data_reg, size: transfer_size, val: &data[0]);
466 break;
467 case 3:
468 /*
469 * Data array after transfer will look like (if status is appended):
470 * data[] = { [0][sample][sample][sample][status] }
471 * Keeping the first byte 0 shifts the status postion by 1 byte to the right.
472 */
473 status_pos = reg_size + 1;
474
475 /* We store 24 bit samples in a 32 bit word. Keep the upper
476 * byte set to zero. */
477 ad_sd_read_reg_raw(sigma_delta, reg: data_reg, size: transfer_size, val: &data[1]);
478 break;
479 }
480
481 /*
482 * For devices sampling only one channel at
483 * once, there is no need for sample number tracking.
484 */
485 if (sigma_delta->active_slots == 1) {
486 iio_push_to_buffers_with_timestamp(indio_dev, data, timestamp: pf->timestamp);
487 goto irq_handled;
488 }
489
490 if (sigma_delta->status_appended) {
491 u8 converted_channel;
492
493 converted_channel = data[status_pos] & sigma_delta->info->status_ch_mask;
494 if (converted_channel != sigma_delta->slots[sigma_delta->current_slot]) {
495 /*
496 * Desync occurred during continuous sampling of multiple channels.
497 * Drop this incomplete sample and start from first channel again.
498 */
499
500 sigma_delta->current_slot = 0;
501 goto irq_handled;
502 }
503 }
504
505 sample_size = indio_dev->channels[0].scan_type.storagebits / 8;
506 sample_pos = sample_size * sigma_delta->current_slot;
507 memcpy(&sigma_delta->samples_buf[sample_pos], data, sample_size);
508 sigma_delta->current_slot++;
509
510 if (sigma_delta->current_slot == sigma_delta->active_slots) {
511 sigma_delta->current_slot = 0;
512 iio_push_to_buffers_with_timestamp(indio_dev, data: sigma_delta->samples_buf,
513 timestamp: pf->timestamp);
514 }
515
516irq_handled:
517 iio_trigger_notify_done(trig: indio_dev->trig);
518 sigma_delta->irq_dis = false;
519 enable_irq(irq: sigma_delta->spi->irq);
520
521 return IRQ_HANDLED;
522}
523
524static bool ad_sd_validate_scan_mask(struct iio_dev *indio_dev, const unsigned long *mask)
525{
526 struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
527
528 return bitmap_weight(src: mask, nbits: indio_dev->masklength) <= sigma_delta->num_slots;
529}
530
531static const struct iio_buffer_setup_ops ad_sd_buffer_setup_ops = {
532 .postenable = &ad_sd_buffer_postenable,
533 .postdisable = &ad_sd_buffer_postdisable,
534 .validate_scan_mask = &ad_sd_validate_scan_mask,
535};
536
537static irqreturn_t ad_sd_data_rdy_trig_poll(int irq, void *private)
538{
539 struct ad_sigma_delta *sigma_delta = private;
540
541 complete(&sigma_delta->completion);
542 disable_irq_nosync(irq);
543 sigma_delta->irq_dis = true;
544 iio_trigger_poll(trig: sigma_delta->trig);
545
546 return IRQ_HANDLED;
547}
548
549/**
550 * ad_sd_validate_trigger() - validate_trigger callback for ad_sigma_delta devices
551 * @indio_dev: The IIO device
552 * @trig: The new trigger
553 *
554 * Returns: 0 if the 'trig' matches the trigger registered by the ad_sigma_delta
555 * device, -EINVAL otherwise.
556 */
557int ad_sd_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig)
558{
559 struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
560
561 if (sigma_delta->trig != trig)
562 return -EINVAL;
563
564 return 0;
565}
566EXPORT_SYMBOL_NS_GPL(ad_sd_validate_trigger, IIO_AD_SIGMA_DELTA);
567
568static int devm_ad_sd_probe_trigger(struct device *dev, struct iio_dev *indio_dev)
569{
570 struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
571 unsigned long irq_flags = irq_get_trigger_type(irq: sigma_delta->spi->irq);
572 int ret;
573
574 if (dev != &sigma_delta->spi->dev) {
575 dev_err(dev, "Trigger parent should be '%s', got '%s'\n",
576 dev_name(dev), dev_name(&sigma_delta->spi->dev));
577 return -EFAULT;
578 }
579
580 sigma_delta->trig = devm_iio_trigger_alloc(dev, "%s-dev%d", indio_dev->name,
581 iio_device_id(indio_dev));
582 if (sigma_delta->trig == NULL)
583 return -ENOMEM;
584
585 init_completion(x: &sigma_delta->completion);
586
587 sigma_delta->irq_dis = true;
588
589 /* the IRQ core clears IRQ_DISABLE_UNLAZY flag when freeing an IRQ */
590 irq_set_status_flags(irq: sigma_delta->spi->irq, set: IRQ_DISABLE_UNLAZY);
591
592 /* Allow overwriting the flags from firmware */
593 if (!irq_flags)
594 irq_flags = sigma_delta->info->irq_flags;
595
596 ret = devm_request_irq(dev, irq: sigma_delta->spi->irq,
597 handler: ad_sd_data_rdy_trig_poll,
598 irqflags: irq_flags | IRQF_NO_AUTOEN,
599 devname: indio_dev->name,
600 dev_id: sigma_delta);
601 if (ret)
602 return ret;
603
604 iio_trigger_set_drvdata(trig: sigma_delta->trig, data: sigma_delta);
605
606 ret = devm_iio_trigger_register(dev, trig_info: sigma_delta->trig);
607 if (ret)
608 return ret;
609
610 /* select default trigger */
611 indio_dev->trig = iio_trigger_get(trig: sigma_delta->trig);
612
613 return 0;
614}
615
616/**
617 * devm_ad_sd_setup_buffer_and_trigger() - Device-managed buffer & trigger setup
618 * @dev: Device object to which to bind the life-time of the resources attached
619 * @indio_dev: The IIO device
620 */
621int devm_ad_sd_setup_buffer_and_trigger(struct device *dev, struct iio_dev *indio_dev)
622{
623 struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
624 int ret;
625
626 sigma_delta->slots = devm_kcalloc(dev, n: sigma_delta->num_slots,
627 size: sizeof(*sigma_delta->slots), GFP_KERNEL);
628 if (!sigma_delta->slots)
629 return -ENOMEM;
630
631 ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
632 &iio_pollfunc_store_time,
633 &ad_sd_trigger_handler,
634 &ad_sd_buffer_setup_ops);
635 if (ret)
636 return ret;
637
638 return devm_ad_sd_probe_trigger(dev, indio_dev);
639}
640EXPORT_SYMBOL_NS_GPL(devm_ad_sd_setup_buffer_and_trigger, IIO_AD_SIGMA_DELTA);
641
642/**
643 * ad_sd_init() - Initializes a ad_sigma_delta struct
644 * @sigma_delta: The ad_sigma_delta device
645 * @indio_dev: The IIO device which the Sigma Delta device is used for
646 * @spi: The SPI device for the ad_sigma_delta device
647 * @info: Device specific callbacks and options
648 *
649 * This function needs to be called before any other operations are performed on
650 * the ad_sigma_delta struct.
651 */
652int ad_sd_init(struct ad_sigma_delta *sigma_delta, struct iio_dev *indio_dev,
653 struct spi_device *spi, const struct ad_sigma_delta_info *info)
654{
655 sigma_delta->spi = spi;
656 sigma_delta->info = info;
657
658 /* If the field is unset in ad_sigma_delta_info, asume there can only be 1 slot. */
659 if (!info->num_slots)
660 sigma_delta->num_slots = 1;
661 else
662 sigma_delta->num_slots = info->num_slots;
663
664 if (sigma_delta->num_slots > 1) {
665 if (!indio_dev->info->update_scan_mode) {
666 dev_err(&spi->dev, "iio_dev lacks update_scan_mode().\n");
667 return -EINVAL;
668 }
669
670 if (!info->disable_all) {
671 dev_err(&spi->dev, "ad_sigma_delta_info lacks disable_all().\n");
672 return -EINVAL;
673 }
674 }
675
676 iio_device_set_drvdata(indio_dev, data: sigma_delta);
677
678 return 0;
679}
680EXPORT_SYMBOL_NS_GPL(ad_sd_init, IIO_AD_SIGMA_DELTA);
681
682MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
683MODULE_DESCRIPTION("Analog Devices Sigma-Delta ADCs");
684MODULE_LICENSE("GPL v2");
685

source code of linux/drivers/iio/adc/ad_sigma_delta.c