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 <[email protected]>
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 <linux/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_STATUS 0x00
33 #define AD_SD_REG_DATA 0x03
34
35 #define AD_SD_REG_STATUS_RDY 0x80
36
37 /**
38 * ad_sd_set_comm() - Set communications register
39 *
40 * @sigma_delta: The sigma delta device
41 * @comm: New value for the communications register
42 */
ad_sd_set_comm(struct ad_sigma_delta * sigma_delta,uint8_t comm)43 void ad_sd_set_comm(struct ad_sigma_delta *sigma_delta, uint8_t comm)
44 {
45 /* Some variants use the lower two bits of the communications register
46 * to select the channel */
47 sigma_delta->comm = comm & AD_SD_COMM_CHAN_MASK;
48 }
49 EXPORT_SYMBOL_NS_GPL(ad_sd_set_comm, "IIO_AD_SIGMA_DELTA");
50
51 /**
52 * ad_sd_write_reg() - Write a register
53 *
54 * @sigma_delta: The sigma delta device
55 * @reg: Address of the register
56 * @size: Size of the register (0-3)
57 * @val: Value to write to the register
58 *
59 * Returns 0 on success, an error code otherwise.
60 **/
ad_sd_write_reg(struct ad_sigma_delta * sigma_delta,unsigned int reg,unsigned int size,unsigned int val)61 int ad_sd_write_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg,
62 unsigned int size, unsigned int val)
63 {
64 uint8_t *data = sigma_delta->tx_buf;
65 struct spi_transfer t = {
66 .tx_buf = data,
67 .len = size + 1,
68 .cs_change = sigma_delta->keep_cs_asserted,
69 };
70 struct spi_message m;
71 int ret;
72
73 data[0] = (reg << sigma_delta->info->addr_shift) | sigma_delta->comm;
74
75 switch (size) {
76 case 3:
77 put_unaligned_be24(val, &data[1]);
78 break;
79 case 2:
80 put_unaligned_be16(val, &data[1]);
81 break;
82 case 1:
83 data[1] = val;
84 break;
85 case 0:
86 break;
87 default:
88 return -EINVAL;
89 }
90
91 spi_message_init(&m);
92 spi_message_add_tail(&t, &m);
93
94 if (sigma_delta->bus_locked)
95 ret = spi_sync_locked(sigma_delta->spi, &m);
96 else
97 ret = spi_sync(sigma_delta->spi, &m);
98
99 return ret;
100 }
101 EXPORT_SYMBOL_NS_GPL(ad_sd_write_reg, "IIO_AD_SIGMA_DELTA");
102
ad_sd_read_reg_raw(struct ad_sigma_delta * sigma_delta,unsigned int reg,unsigned int size,uint8_t * val)103 static int ad_sd_read_reg_raw(struct ad_sigma_delta *sigma_delta,
104 unsigned int reg, unsigned int size, uint8_t *val)
105 {
106 uint8_t *data = sigma_delta->tx_buf;
107 int ret;
108 struct spi_transfer t[] = {
109 {
110 .tx_buf = data,
111 .len = 1,
112 }, {
113 .rx_buf = val,
114 .len = size,
115 .cs_change = sigma_delta->keep_cs_asserted,
116 },
117 };
118 struct spi_message m;
119
120 spi_message_init(&m);
121
122 if (sigma_delta->info->has_registers) {
123 data[0] = reg << sigma_delta->info->addr_shift;
124 data[0] |= sigma_delta->info->read_mask;
125 data[0] |= sigma_delta->comm;
126 spi_message_add_tail(&t[0], &m);
127 }
128 spi_message_add_tail(&t[1], &m);
129
130 if (sigma_delta->bus_locked)
131 ret = spi_sync_locked(sigma_delta->spi, &m);
132 else
133 ret = spi_sync(sigma_delta->spi, &m);
134
135 return ret;
136 }
137
138 /**
139 * ad_sd_read_reg() - Read a register
140 *
141 * @sigma_delta: The sigma delta device
142 * @reg: Address of the register
143 * @size: Size of the register (1-4)
144 * @val: Read value
145 *
146 * Returns 0 on success, an error code otherwise.
147 **/
ad_sd_read_reg(struct ad_sigma_delta * sigma_delta,unsigned int reg,unsigned int size,unsigned int * val)148 int ad_sd_read_reg(struct ad_sigma_delta *sigma_delta,
149 unsigned int reg, unsigned int size, unsigned int *val)
150 {
151 int ret;
152
153 ret = ad_sd_read_reg_raw(sigma_delta, reg, size, sigma_delta->rx_buf);
154 if (ret < 0)
155 goto out;
156
157 switch (size) {
158 case 4:
159 *val = get_unaligned_be32(sigma_delta->rx_buf);
160 break;
161 case 3:
162 *val = get_unaligned_be24(sigma_delta->rx_buf);
163 break;
164 case 2:
165 *val = get_unaligned_be16(sigma_delta->rx_buf);
166 break;
167 case 1:
168 *val = sigma_delta->rx_buf[0];
169 break;
170 default:
171 ret = -EINVAL;
172 break;
173 }
174
175 out:
176 return ret;
177 }
178 EXPORT_SYMBOL_NS_GPL(ad_sd_read_reg, "IIO_AD_SIGMA_DELTA");
179
180 /**
181 * ad_sd_reset() - Reset the serial interface
182 *
183 * @sigma_delta: The sigma delta device
184 *
185 * Returns 0 on success, an error code otherwise.
186 **/
ad_sd_reset(struct ad_sigma_delta * sigma_delta)187 int ad_sd_reset(struct ad_sigma_delta *sigma_delta)
188 {
189 unsigned int reset_length = sigma_delta->info->num_resetclks;
190 uint8_t *buf;
191 unsigned int size;
192 int ret;
193
194 size = DIV_ROUND_UP(reset_length, 8);
195 buf = kcalloc(size, sizeof(*buf), GFP_KERNEL);
196 if (!buf)
197 return -ENOMEM;
198
199 memset(buf, 0xff, size);
200 ret = spi_write(sigma_delta->spi, buf, size);
201 kfree(buf);
202
203 return ret;
204 }
205 EXPORT_SYMBOL_NS_GPL(ad_sd_reset, "IIO_AD_SIGMA_DELTA");
206
ad_sd_disable_irq(struct ad_sigma_delta * sigma_delta)207 static bool ad_sd_disable_irq(struct ad_sigma_delta *sigma_delta)
208 {
209 guard(spinlock_irqsave)(&sigma_delta->irq_lock);
210
211 /* It's already off, return false to indicate nothing was changed */
212 if (sigma_delta->irq_dis)
213 return false;
214
215 sigma_delta->irq_dis = true;
216 disable_irq_nosync(sigma_delta->irq_line);
217 return true;
218 }
219
ad_sd_enable_irq(struct ad_sigma_delta * sigma_delta)220 static void ad_sd_enable_irq(struct ad_sigma_delta *sigma_delta)
221 {
222 guard(spinlock_irqsave)(&sigma_delta->irq_lock);
223
224 sigma_delta->irq_dis = false;
225 enable_irq(sigma_delta->irq_line);
226 }
227
228 #define AD_SD_CLEAR_DATA_BUFLEN 9
229
230 /* Called with `sigma_delta->bus_locked == true` only. */
ad_sigma_delta_clear_pending_event(struct ad_sigma_delta * sigma_delta)231 static int ad_sigma_delta_clear_pending_event(struct ad_sigma_delta *sigma_delta)
232 {
233 bool pending_event;
234 unsigned int data_read_len = BITS_TO_BYTES(sigma_delta->info->num_resetclks);
235 u8 *data;
236 struct spi_transfer t[] = {
237 {
238 .len = 1,
239 }, {
240 .len = data_read_len,
241 }
242 };
243 struct spi_message m;
244 int ret;
245
246 /*
247 * Read R̅D̅Y̅ pin (if possible) or status register to check if there is an
248 * old event.
249 */
250 if (sigma_delta->rdy_gpiod) {
251 pending_event = gpiod_get_value(sigma_delta->rdy_gpiod);
252 } else {
253 unsigned int status_reg;
254
255 ret = ad_sd_read_reg(sigma_delta, AD_SD_REG_STATUS, 1, &status_reg);
256 if (ret)
257 return ret;
258
259 pending_event = !(status_reg & AD_SD_REG_STATUS_RDY);
260 }
261
262 if (!pending_event)
263 return 0;
264
265 /*
266 * In general the size of the data register is unknown. It varies from
267 * device to device, might be one byte longer if CONTROL.DATA_STATUS is
268 * set and even varies on some devices depending on which input is
269 * selected. So send one byte to start reading the data register and
270 * then just clock for some bytes with DIN (aka MOSI) high to not
271 * confuse the register access state machine after the data register was
272 * completely read. Note however that the sequence length must be
273 * shorter than the reset procedure.
274 */
275
276 data = kzalloc(data_read_len + 1, GFP_KERNEL);
277 if (!data)
278 return -ENOMEM;
279
280 spi_message_init(&m);
281 if (sigma_delta->info->has_registers) {
282 unsigned int data_reg = sigma_delta->info->data_reg ?: AD_SD_REG_DATA;
283
284 data[0] = data_reg << sigma_delta->info->addr_shift;
285 data[0] |= sigma_delta->info->read_mask;
286 data[0] |= sigma_delta->comm;
287 t[0].tx_buf = data;
288 spi_message_add_tail(&t[0], &m);
289 }
290
291 /*
292 * The first transferred byte is part of the real data register,
293 * so this doesn't need to be 0xff. In the remaining
294 * `data_read_len - 1` bytes are less than $num_resetclks ones.
295 */
296 t[1].tx_buf = data + 1;
297 data[1] = 0x00;
298 memset(data + 2, 0xff, data_read_len - 1);
299 spi_message_add_tail(&t[1], &m);
300
301 ret = spi_sync_locked(sigma_delta->spi, &m);
302
303 kfree(data);
304
305 return ret;
306 }
307
ad_sd_calibrate(struct ad_sigma_delta * sigma_delta,unsigned int mode,unsigned int channel)308 int ad_sd_calibrate(struct ad_sigma_delta *sigma_delta,
309 unsigned int mode, unsigned int channel)
310 {
311 int ret;
312 unsigned long time_left;
313
314 ret = ad_sigma_delta_set_channel(sigma_delta, channel);
315 if (ret)
316 return ret;
317
318 spi_bus_lock(sigma_delta->spi->controller);
319 sigma_delta->bus_locked = true;
320 sigma_delta->keep_cs_asserted = true;
321 reinit_completion(&sigma_delta->completion);
322
323 ret = ad_sigma_delta_clear_pending_event(sigma_delta);
324 if (ret)
325 goto out;
326
327 ret = ad_sigma_delta_set_mode(sigma_delta, mode);
328 if (ret < 0)
329 goto out;
330
331 ad_sd_enable_irq(sigma_delta);
332 time_left = wait_for_completion_timeout(&sigma_delta->completion, 2 * HZ);
333 if (time_left == 0) {
334 ad_sd_disable_irq(sigma_delta);
335 ret = -EIO;
336 } else {
337 ret = 0;
338 }
339 out:
340 sigma_delta->keep_cs_asserted = false;
341 ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE);
342 ad_sigma_delta_disable_one(sigma_delta, channel);
343 sigma_delta->bus_locked = false;
344 spi_bus_unlock(sigma_delta->spi->controller);
345
346 return ret;
347 }
348 EXPORT_SYMBOL_NS_GPL(ad_sd_calibrate, "IIO_AD_SIGMA_DELTA");
349
350 /**
351 * ad_sd_calibrate_all() - Performs channel calibration
352 * @sigma_delta: The sigma delta device
353 * @cb: Array of channels and calibration type to perform
354 * @n: Number of items in cb
355 *
356 * Returns 0 on success, an error code otherwise.
357 **/
ad_sd_calibrate_all(struct ad_sigma_delta * sigma_delta,const struct ad_sd_calib_data * cb,unsigned int n)358 int ad_sd_calibrate_all(struct ad_sigma_delta *sigma_delta,
359 const struct ad_sd_calib_data *cb, unsigned int n)
360 {
361 unsigned int i;
362 int ret;
363
364 for (i = 0; i < n; i++) {
365 ret = ad_sd_calibrate(sigma_delta, cb[i].mode, cb[i].channel);
366 if (ret)
367 return ret;
368 }
369
370 return 0;
371 }
372 EXPORT_SYMBOL_NS_GPL(ad_sd_calibrate_all, "IIO_AD_SIGMA_DELTA");
373
374 /**
375 * ad_sigma_delta_single_conversion() - Performs a single data conversion
376 * @indio_dev: The IIO device
377 * @chan: The conversion is done for this channel
378 * @val: Pointer to the location where to store the read value
379 *
380 * Returns: 0 on success, an error value otherwise.
381 */
ad_sigma_delta_single_conversion(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,int * val)382 int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev,
383 const struct iio_chan_spec *chan, int *val)
384 {
385 struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
386 unsigned int sample, raw_sample;
387 unsigned int data_reg;
388 int ret = 0;
389
390 ret = iio_device_claim_direct_mode(indio_dev);
391 if (ret)
392 return ret;
393
394 ad_sigma_delta_set_channel(sigma_delta, chan->address);
395
396 spi_bus_lock(sigma_delta->spi->controller);
397 sigma_delta->bus_locked = true;
398 sigma_delta->keep_cs_asserted = true;
399 reinit_completion(&sigma_delta->completion);
400
401 ret = ad_sigma_delta_clear_pending_event(sigma_delta);
402 if (ret)
403 goto out_unlock;
404
405 ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_SINGLE);
406
407 ad_sd_enable_irq(sigma_delta);
408 ret = wait_for_completion_interruptible_timeout(
409 &sigma_delta->completion, HZ);
410
411 if (ret == 0)
412 ret = -EIO;
413 if (ret < 0)
414 goto out;
415
416 if (sigma_delta->info->data_reg != 0)
417 data_reg = sigma_delta->info->data_reg;
418 else
419 data_reg = AD_SD_REG_DATA;
420
421 ret = ad_sd_read_reg(sigma_delta, data_reg,
422 DIV_ROUND_UP(chan->scan_type.realbits + chan->scan_type.shift, 8),
423 &raw_sample);
424
425 out:
426 ad_sd_disable_irq(sigma_delta);
427
428 ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE);
429 ad_sigma_delta_disable_one(sigma_delta, chan->address);
430
431 out_unlock:
432 sigma_delta->keep_cs_asserted = false;
433 sigma_delta->bus_locked = false;
434 spi_bus_unlock(sigma_delta->spi->controller);
435 iio_device_release_direct_mode(indio_dev);
436
437 if (ret)
438 return ret;
439
440 sample = raw_sample >> chan->scan_type.shift;
441 sample &= (1 << chan->scan_type.realbits) - 1;
442 *val = sample;
443
444 ret = ad_sigma_delta_postprocess_sample(sigma_delta, raw_sample);
445 if (ret)
446 return ret;
447
448 return IIO_VAL_INT;
449 }
450 EXPORT_SYMBOL_NS_GPL(ad_sigma_delta_single_conversion, "IIO_AD_SIGMA_DELTA");
451
ad_sd_buffer_postenable(struct iio_dev * indio_dev)452 static int ad_sd_buffer_postenable(struct iio_dev *indio_dev)
453 {
454 struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
455 unsigned int i, slot, samples_buf_size;
456 unsigned int channel;
457 uint8_t *samples_buf;
458 int ret;
459
460 if (sigma_delta->num_slots == 1) {
461 channel = find_first_bit(indio_dev->active_scan_mask,
462 iio_get_masklength(indio_dev));
463 ret = ad_sigma_delta_set_channel(sigma_delta,
464 indio_dev->channels[channel].address);
465 if (ret)
466 return ret;
467 slot = 1;
468 } else {
469 /*
470 * At this point update_scan_mode already enabled the required channels.
471 * For sigma-delta sequencer drivers with multiple slots, an update_scan_mode
472 * implementation is mandatory.
473 */
474 slot = 0;
475 iio_for_each_active_channel(indio_dev, i) {
476 sigma_delta->slots[slot] = indio_dev->channels[i].address;
477 slot++;
478 }
479 }
480
481 sigma_delta->active_slots = slot;
482 sigma_delta->current_slot = 0;
483
484 if (sigma_delta->active_slots > 1) {
485 ret = ad_sigma_delta_append_status(sigma_delta, true);
486 if (ret)
487 return ret;
488 }
489
490 samples_buf_size = ALIGN(slot * indio_dev->channels[0].scan_type.storagebits, 8);
491 samples_buf_size += sizeof(int64_t);
492 samples_buf = devm_krealloc(&sigma_delta->spi->dev, sigma_delta->samples_buf,
493 samples_buf_size, GFP_KERNEL);
494 if (!samples_buf)
495 return -ENOMEM;
496
497 sigma_delta->samples_buf = samples_buf;
498
499 spi_bus_lock(sigma_delta->spi->controller);
500 sigma_delta->bus_locked = true;
501 sigma_delta->keep_cs_asserted = true;
502
503 ret = ad_sigma_delta_clear_pending_event(sigma_delta);
504 if (ret)
505 goto err_unlock;
506
507 ret = ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_CONTINUOUS);
508 if (ret)
509 goto err_unlock;
510
511 ad_sd_enable_irq(sigma_delta);
512
513 return 0;
514
515 err_unlock:
516 spi_bus_unlock(sigma_delta->spi->controller);
517
518 return ret;
519 }
520
ad_sd_buffer_postdisable(struct iio_dev * indio_dev)521 static int ad_sd_buffer_postdisable(struct iio_dev *indio_dev)
522 {
523 struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
524
525 reinit_completion(&sigma_delta->completion);
526 wait_for_completion_timeout(&sigma_delta->completion, HZ);
527
528 ad_sd_disable_irq(sigma_delta);
529
530 sigma_delta->keep_cs_asserted = false;
531 ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE);
532
533 if (sigma_delta->status_appended)
534 ad_sigma_delta_append_status(sigma_delta, false);
535
536 ad_sigma_delta_disable_all(sigma_delta);
537 sigma_delta->bus_locked = false;
538 return spi_bus_unlock(sigma_delta->spi->controller);
539 }
540
ad_sd_trigger_handler(int irq,void * p)541 static irqreturn_t ad_sd_trigger_handler(int irq, void *p)
542 {
543 struct iio_poll_func *pf = p;
544 struct iio_dev *indio_dev = pf->indio_dev;
545 struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
546 uint8_t *data = sigma_delta->rx_buf;
547 unsigned int transfer_size;
548 unsigned int sample_size;
549 unsigned int sample_pos;
550 unsigned int status_pos;
551 unsigned int reg_size;
552 unsigned int data_reg;
553
554 reg_size = indio_dev->channels[0].scan_type.realbits +
555 indio_dev->channels[0].scan_type.shift;
556 reg_size = DIV_ROUND_UP(reg_size, 8);
557
558 if (sigma_delta->info->data_reg != 0)
559 data_reg = sigma_delta->info->data_reg;
560 else
561 data_reg = AD_SD_REG_DATA;
562
563 /* Status word will be appended to the sample during transfer */
564 if (sigma_delta->status_appended)
565 transfer_size = reg_size + 1;
566 else
567 transfer_size = reg_size;
568
569 switch (reg_size) {
570 case 4:
571 case 2:
572 case 1:
573 status_pos = reg_size;
574 ad_sd_read_reg_raw(sigma_delta, data_reg, transfer_size, &data[0]);
575 break;
576 case 3:
577 /*
578 * Data array after transfer will look like (if status is appended):
579 * data[] = { [0][sample][sample][sample][status] }
580 * Keeping the first byte 0 shifts the status position by 1 byte to the right.
581 */
582 status_pos = reg_size + 1;
583
584 /* We store 24 bit samples in a 32 bit word. Keep the upper
585 * byte set to zero. */
586 ad_sd_read_reg_raw(sigma_delta, data_reg, transfer_size, &data[1]);
587 break;
588 }
589
590 /*
591 * For devices sampling only one channel at
592 * once, there is no need for sample number tracking.
593 */
594 if (sigma_delta->active_slots == 1) {
595 iio_push_to_buffers_with_timestamp(indio_dev, data, pf->timestamp);
596 goto irq_handled;
597 }
598
599 if (sigma_delta->status_appended) {
600 u8 converted_channel;
601
602 converted_channel = data[status_pos] & sigma_delta->info->status_ch_mask;
603 if (converted_channel != sigma_delta->slots[sigma_delta->current_slot]) {
604 /*
605 * Desync occurred during continuous sampling of multiple channels.
606 * Drop this incomplete sample and start from first channel again.
607 */
608
609 sigma_delta->current_slot = 0;
610 goto irq_handled;
611 }
612 }
613
614 sample_size = indio_dev->channels[0].scan_type.storagebits / 8;
615 sample_pos = sample_size * sigma_delta->current_slot;
616 memcpy(&sigma_delta->samples_buf[sample_pos], data, sample_size);
617 sigma_delta->current_slot++;
618
619 if (sigma_delta->current_slot == sigma_delta->active_slots) {
620 sigma_delta->current_slot = 0;
621 iio_push_to_buffers_with_timestamp(indio_dev, sigma_delta->samples_buf,
622 pf->timestamp);
623 }
624
625 irq_handled:
626 iio_trigger_notify_done(indio_dev->trig);
627 ad_sd_enable_irq(sigma_delta);
628
629 return IRQ_HANDLED;
630 }
631
ad_sd_validate_scan_mask(struct iio_dev * indio_dev,const unsigned long * mask)632 static bool ad_sd_validate_scan_mask(struct iio_dev *indio_dev, const unsigned long *mask)
633 {
634 struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
635
636 return bitmap_weight(mask, iio_get_masklength(indio_dev)) <= sigma_delta->num_slots;
637 }
638
639 static const struct iio_buffer_setup_ops ad_sd_buffer_setup_ops = {
640 .postenable = &ad_sd_buffer_postenable,
641 .postdisable = &ad_sd_buffer_postdisable,
642 .validate_scan_mask = &ad_sd_validate_scan_mask,
643 };
644
ad_sd_data_rdy_trig_poll(int irq,void * private)645 static irqreturn_t ad_sd_data_rdy_trig_poll(int irq, void *private)
646 {
647 struct ad_sigma_delta *sigma_delta = private;
648
649 /*
650 * AD7124 and a few others use the same physical line for interrupt
651 * reporting (R̅D̅Y̅) and MISO.
652 * As MISO toggles when reading a register, this likely results in a
653 * pending interrupt. This has two consequences: a) The irq might
654 * trigger immediately after it's enabled even though the conversion
655 * isn't done yet; and b) checking the STATUS register's R̅D̅Y̅ flag is
656 * off-limits as reading that would trigger another irq event.
657 *
658 * So read the MOSI line as GPIO (if available) and only trigger the irq
659 * if the line is active. Without such a GPIO assume this is a valid
660 * interrupt.
661 *
662 * Also as disable_irq_nosync() is used to disable the irq, only act if
663 * the irq wasn't disabled before.
664 */
665 if ((!sigma_delta->rdy_gpiod || gpiod_get_value(sigma_delta->rdy_gpiod)) &&
666 ad_sd_disable_irq(sigma_delta)) {
667 complete(&sigma_delta->completion);
668 iio_trigger_poll(sigma_delta->trig);
669
670 return IRQ_HANDLED;
671 }
672
673 return IRQ_NONE;
674 }
675
676 /**
677 * ad_sd_validate_trigger() - validate_trigger callback for ad_sigma_delta devices
678 * @indio_dev: The IIO device
679 * @trig: The new trigger
680 *
681 * Returns: 0 if the 'trig' matches the trigger registered by the ad_sigma_delta
682 * device, -EINVAL otherwise.
683 */
ad_sd_validate_trigger(struct iio_dev * indio_dev,struct iio_trigger * trig)684 int ad_sd_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig)
685 {
686 struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
687
688 if (sigma_delta->trig != trig)
689 return -EINVAL;
690
691 return 0;
692 }
693 EXPORT_SYMBOL_NS_GPL(ad_sd_validate_trigger, "IIO_AD_SIGMA_DELTA");
694
devm_ad_sd_probe_trigger(struct device * dev,struct iio_dev * indio_dev)695 static int devm_ad_sd_probe_trigger(struct device *dev, struct iio_dev *indio_dev)
696 {
697 struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
698 unsigned long irq_flags = irq_get_trigger_type(sigma_delta->irq_line);
699 int ret;
700
701 if (dev != &sigma_delta->spi->dev) {
702 dev_err(dev, "Trigger parent should be '%s', got '%s'\n",
703 dev_name(dev), dev_name(&sigma_delta->spi->dev));
704 return -EFAULT;
705 }
706
707 sigma_delta->trig = devm_iio_trigger_alloc(dev, "%s-dev%d", indio_dev->name,
708 iio_device_id(indio_dev));
709 if (sigma_delta->trig == NULL)
710 return -ENOMEM;
711
712 init_completion(&sigma_delta->completion);
713
714 sigma_delta->irq_dis = true;
715
716 /* the IRQ core clears IRQ_DISABLE_UNLAZY flag when freeing an IRQ */
717 irq_set_status_flags(sigma_delta->irq_line, IRQ_DISABLE_UNLAZY);
718
719 /* Allow overwriting the flags from firmware */
720 if (!irq_flags)
721 irq_flags = sigma_delta->info->irq_flags;
722
723 ret = devm_request_irq(dev, sigma_delta->irq_line,
724 ad_sd_data_rdy_trig_poll,
725 irq_flags | IRQF_NO_AUTOEN,
726 indio_dev->name,
727 sigma_delta);
728 if (ret)
729 return ret;
730
731 iio_trigger_set_drvdata(sigma_delta->trig, sigma_delta);
732
733 ret = devm_iio_trigger_register(dev, sigma_delta->trig);
734 if (ret)
735 return ret;
736
737 /* select default trigger */
738 indio_dev->trig = iio_trigger_get(sigma_delta->trig);
739
740 return 0;
741 }
742
743 /**
744 * devm_ad_sd_setup_buffer_and_trigger() - Device-managed buffer & trigger setup
745 * @dev: Device object to which to bind the life-time of the resources attached
746 * @indio_dev: The IIO device
747 */
devm_ad_sd_setup_buffer_and_trigger(struct device * dev,struct iio_dev * indio_dev)748 int devm_ad_sd_setup_buffer_and_trigger(struct device *dev, struct iio_dev *indio_dev)
749 {
750 struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
751 int ret;
752
753 sigma_delta->slots = devm_kcalloc(dev, sigma_delta->num_slots,
754 sizeof(*sigma_delta->slots), GFP_KERNEL);
755 if (!sigma_delta->slots)
756 return -ENOMEM;
757
758 ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
759 &iio_pollfunc_store_time,
760 &ad_sd_trigger_handler,
761 &ad_sd_buffer_setup_ops);
762 if (ret)
763 return ret;
764
765 return devm_ad_sd_probe_trigger(dev, indio_dev);
766 }
767 EXPORT_SYMBOL_NS_GPL(devm_ad_sd_setup_buffer_and_trigger, "IIO_AD_SIGMA_DELTA");
768
769 /**
770 * ad_sd_init() - Initializes a ad_sigma_delta struct
771 * @sigma_delta: The ad_sigma_delta device
772 * @indio_dev: The IIO device which the Sigma Delta device is used for
773 * @spi: The SPI device for the ad_sigma_delta device
774 * @info: Device specific callbacks and options
775 *
776 * This function needs to be called before any other operations are performed on
777 * the ad_sigma_delta struct.
778 */
ad_sd_init(struct ad_sigma_delta * sigma_delta,struct iio_dev * indio_dev,struct spi_device * spi,const struct ad_sigma_delta_info * info)779 int ad_sd_init(struct ad_sigma_delta *sigma_delta, struct iio_dev *indio_dev,
780 struct spi_device *spi, const struct ad_sigma_delta_info *info)
781 {
782 sigma_delta->spi = spi;
783 sigma_delta->info = info;
784
785 /* If the field is unset in ad_sigma_delta_info, assume there can only be 1 slot. */
786 if (!info->num_slots)
787 sigma_delta->num_slots = 1;
788 else
789 sigma_delta->num_slots = info->num_slots;
790
791 if (sigma_delta->num_slots > 1) {
792 if (!indio_dev->info->update_scan_mode) {
793 dev_err(&spi->dev, "iio_dev lacks update_scan_mode().\n");
794 return -EINVAL;
795 }
796
797 if (!info->disable_all) {
798 dev_err(&spi->dev, "ad_sigma_delta_info lacks disable_all().\n");
799 return -EINVAL;
800 }
801 }
802
803 spin_lock_init(&sigma_delta->irq_lock);
804
805 if (info->irq_line)
806 sigma_delta->irq_line = info->irq_line;
807 else
808 sigma_delta->irq_line = spi->irq;
809
810 sigma_delta->rdy_gpiod = devm_gpiod_get_optional(&spi->dev, "rdy", GPIOD_IN);
811 if (IS_ERR(sigma_delta->rdy_gpiod))
812 return dev_err_probe(&spi->dev, PTR_ERR(sigma_delta->rdy_gpiod),
813 "Failed to find rdy gpio\n");
814
815 if (sigma_delta->rdy_gpiod && !sigma_delta->irq_line) {
816 sigma_delta->irq_line = gpiod_to_irq(sigma_delta->rdy_gpiod);
817 if (sigma_delta->irq_line < 0)
818 return sigma_delta->irq_line;
819 }
820
821 iio_device_set_drvdata(indio_dev, sigma_delta);
822
823 return 0;
824 }
825 EXPORT_SYMBOL_NS_GPL(ad_sd_init, "IIO_AD_SIGMA_DELTA");
826
827 MODULE_AUTHOR("Lars-Peter Clausen <[email protected]>");
828 MODULE_DESCRIPTION("Analog Devices Sigma-Delta ADCs");
829 MODULE_LICENSE("GPL v2");
830