dm writecache: add cond_resched to loop in persistent_memory_claim()
[linux/fpc-iii.git] / drivers / iio / adc / ad7606.c
blobe4683a68522a4502957887e475f951e5be74e53b
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * AD7606 SPI ADC driver
5 * Copyright 2011 Analog Devices Inc.
6 */
8 #include <linux/delay.h>
9 #include <linux/device.h>
10 #include <linux/err.h>
11 #include <linux/gpio/consumer.h>
12 #include <linux/interrupt.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/regulator/consumer.h>
16 #include <linux/sched.h>
17 #include <linux/slab.h>
18 #include <linux/sysfs.h>
19 #include <linux/util_macros.h>
21 #include <linux/iio/iio.h>
22 #include <linux/iio/buffer.h>
23 #include <linux/iio/sysfs.h>
24 #include <linux/iio/trigger.h>
25 #include <linux/iio/triggered_buffer.h>
26 #include <linux/iio/trigger_consumer.h>
28 #include "ad7606.h"
31 * Scales are computed as 5000/32768 and 10000/32768 respectively,
32 * so that when applied to the raw values they provide mV values
34 static const unsigned int ad7606_scale_avail[2] = {
35 152588, 305176
39 static const unsigned int ad7616_sw_scale_avail[3] = {
40 76293, 152588, 305176
43 static const unsigned int ad7606_oversampling_avail[7] = {
44 1, 2, 4, 8, 16, 32, 64,
47 static const unsigned int ad7616_oversampling_avail[8] = {
48 1, 2, 4, 8, 16, 32, 64, 128,
51 static int ad7606_reset(struct ad7606_state *st)
53 if (st->gpio_reset) {
54 gpiod_set_value(st->gpio_reset, 1);
55 ndelay(100); /* t_reset >= 100ns */
56 gpiod_set_value(st->gpio_reset, 0);
57 return 0;
60 return -ENODEV;
63 static int ad7606_reg_access(struct iio_dev *indio_dev,
64 unsigned int reg,
65 unsigned int writeval,
66 unsigned int *readval)
68 struct ad7606_state *st = iio_priv(indio_dev);
69 int ret;
71 mutex_lock(&st->lock);
72 if (readval) {
73 ret = st->bops->reg_read(st, reg);
74 if (ret < 0)
75 goto err_unlock;
76 *readval = ret;
77 ret = 0;
78 } else {
79 ret = st->bops->reg_write(st, reg, writeval);
81 err_unlock:
82 mutex_unlock(&st->lock);
83 return ret;
86 static int ad7606_read_samples(struct ad7606_state *st)
88 unsigned int num = st->chip_info->num_channels - 1;
89 u16 *data = st->data;
90 int ret;
93 * The frstdata signal is set to high while and after reading the sample
94 * of the first channel and low for all other channels. This can be used
95 * to check that the incoming data is correctly aligned. During normal
96 * operation the data should never become unaligned, but some glitch or
97 * electrostatic discharge might cause an extra read or clock cycle.
98 * Monitoring the frstdata signal allows to recover from such failure
99 * situations.
102 if (st->gpio_frstdata) {
103 ret = st->bops->read_block(st->dev, 1, data);
104 if (ret)
105 return ret;
107 if (!gpiod_get_value(st->gpio_frstdata)) {
108 ad7606_reset(st);
109 return -EIO;
112 data++;
113 num--;
116 return st->bops->read_block(st->dev, num, data);
119 static irqreturn_t ad7606_trigger_handler(int irq, void *p)
121 struct iio_poll_func *pf = p;
122 struct iio_dev *indio_dev = pf->indio_dev;
123 struct ad7606_state *st = iio_priv(indio_dev);
124 int ret;
126 mutex_lock(&st->lock);
128 ret = ad7606_read_samples(st);
129 if (ret == 0)
130 iio_push_to_buffers_with_timestamp(indio_dev, st->data,
131 iio_get_time_ns(indio_dev));
133 iio_trigger_notify_done(indio_dev->trig);
134 /* The rising edge of the CONVST signal starts a new conversion. */
135 gpiod_set_value(st->gpio_convst, 1);
137 mutex_unlock(&st->lock);
139 return IRQ_HANDLED;
142 static int ad7606_scan_direct(struct iio_dev *indio_dev, unsigned int ch)
144 struct ad7606_state *st = iio_priv(indio_dev);
145 int ret;
147 gpiod_set_value(st->gpio_convst, 1);
148 ret = wait_for_completion_timeout(&st->completion,
149 msecs_to_jiffies(1000));
150 if (!ret) {
151 ret = -ETIMEDOUT;
152 goto error_ret;
155 ret = ad7606_read_samples(st);
156 if (ret == 0)
157 ret = st->data[ch];
159 error_ret:
160 gpiod_set_value(st->gpio_convst, 0);
162 return ret;
165 static int ad7606_read_raw(struct iio_dev *indio_dev,
166 struct iio_chan_spec const *chan,
167 int *val,
168 int *val2,
169 long m)
171 int ret, ch = 0;
172 struct ad7606_state *st = iio_priv(indio_dev);
174 switch (m) {
175 case IIO_CHAN_INFO_RAW:
176 ret = iio_device_claim_direct_mode(indio_dev);
177 if (ret)
178 return ret;
180 ret = ad7606_scan_direct(indio_dev, chan->address);
181 iio_device_release_direct_mode(indio_dev);
183 if (ret < 0)
184 return ret;
185 *val = (short)ret;
186 return IIO_VAL_INT;
187 case IIO_CHAN_INFO_SCALE:
188 if (st->sw_mode_en)
189 ch = chan->address;
190 *val = 0;
191 *val2 = st->scale_avail[st->range[ch]];
192 return IIO_VAL_INT_PLUS_MICRO;
193 case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
194 *val = st->oversampling;
195 return IIO_VAL_INT;
197 return -EINVAL;
200 static ssize_t ad7606_show_avail(char *buf, const unsigned int *vals,
201 unsigned int n, bool micros)
203 size_t len = 0;
204 int i;
206 for (i = 0; i < n; i++) {
207 len += scnprintf(buf + len, PAGE_SIZE - len,
208 micros ? "0.%06u " : "%u ", vals[i]);
210 buf[len - 1] = '\n';
212 return len;
215 static ssize_t in_voltage_scale_available_show(struct device *dev,
216 struct device_attribute *attr,
217 char *buf)
219 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
220 struct ad7606_state *st = iio_priv(indio_dev);
222 return ad7606_show_avail(buf, st->scale_avail, st->num_scales, true);
225 static IIO_DEVICE_ATTR_RO(in_voltage_scale_available, 0);
227 static int ad7606_write_scale_hw(struct iio_dev *indio_dev, int ch, int val)
229 struct ad7606_state *st = iio_priv(indio_dev);
231 gpiod_set_value(st->gpio_range, val);
233 return 0;
236 static int ad7606_write_os_hw(struct iio_dev *indio_dev, int val)
238 struct ad7606_state *st = iio_priv(indio_dev);
239 DECLARE_BITMAP(values, 3);
241 values[0] = val;
243 gpiod_set_array_value(ARRAY_SIZE(values), st->gpio_os->desc,
244 st->gpio_os->info, values);
246 /* AD7616 requires a reset to update value */
247 if (st->chip_info->os_req_reset)
248 ad7606_reset(st);
250 return 0;
253 static int ad7606_write_raw(struct iio_dev *indio_dev,
254 struct iio_chan_spec const *chan,
255 int val,
256 int val2,
257 long mask)
259 struct ad7606_state *st = iio_priv(indio_dev);
260 int i, ret, ch = 0;
262 switch (mask) {
263 case IIO_CHAN_INFO_SCALE:
264 mutex_lock(&st->lock);
265 i = find_closest(val2, st->scale_avail, st->num_scales);
266 if (st->sw_mode_en)
267 ch = chan->address;
268 ret = st->write_scale(indio_dev, ch, i);
269 if (ret < 0) {
270 mutex_unlock(&st->lock);
271 return ret;
273 st->range[ch] = i;
274 mutex_unlock(&st->lock);
276 return 0;
277 case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
278 if (val2)
279 return -EINVAL;
280 i = find_closest(val, st->oversampling_avail,
281 st->num_os_ratios);
282 mutex_lock(&st->lock);
283 ret = st->write_os(indio_dev, i);
284 if (ret < 0) {
285 mutex_unlock(&st->lock);
286 return ret;
288 st->oversampling = st->oversampling_avail[i];
289 mutex_unlock(&st->lock);
291 return 0;
292 default:
293 return -EINVAL;
297 static ssize_t ad7606_oversampling_ratio_avail(struct device *dev,
298 struct device_attribute *attr,
299 char *buf)
301 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
302 struct ad7606_state *st = iio_priv(indio_dev);
304 return ad7606_show_avail(buf, st->oversampling_avail,
305 st->num_os_ratios, false);
308 static IIO_DEVICE_ATTR(oversampling_ratio_available, 0444,
309 ad7606_oversampling_ratio_avail, NULL, 0);
311 static struct attribute *ad7606_attributes_os_and_range[] = {
312 &iio_dev_attr_in_voltage_scale_available.dev_attr.attr,
313 &iio_dev_attr_oversampling_ratio_available.dev_attr.attr,
314 NULL,
317 static const struct attribute_group ad7606_attribute_group_os_and_range = {
318 .attrs = ad7606_attributes_os_and_range,
321 static struct attribute *ad7606_attributes_os[] = {
322 &iio_dev_attr_oversampling_ratio_available.dev_attr.attr,
323 NULL,
326 static const struct attribute_group ad7606_attribute_group_os = {
327 .attrs = ad7606_attributes_os,
330 static struct attribute *ad7606_attributes_range[] = {
331 &iio_dev_attr_in_voltage_scale_available.dev_attr.attr,
332 NULL,
335 static const struct attribute_group ad7606_attribute_group_range = {
336 .attrs = ad7606_attributes_range,
339 static const struct iio_chan_spec ad7605_channels[] = {
340 IIO_CHAN_SOFT_TIMESTAMP(4),
341 AD7605_CHANNEL(0),
342 AD7605_CHANNEL(1),
343 AD7605_CHANNEL(2),
344 AD7605_CHANNEL(3),
347 static const struct iio_chan_spec ad7606_channels[] = {
348 IIO_CHAN_SOFT_TIMESTAMP(8),
349 AD7606_CHANNEL(0),
350 AD7606_CHANNEL(1),
351 AD7606_CHANNEL(2),
352 AD7606_CHANNEL(3),
353 AD7606_CHANNEL(4),
354 AD7606_CHANNEL(5),
355 AD7606_CHANNEL(6),
356 AD7606_CHANNEL(7),
360 * The current assumption that this driver makes for AD7616, is that it's
361 * working in Hardware Mode with Serial, Burst and Sequencer modes activated.
362 * To activate them, following pins must be pulled high:
363 * -SER/PAR
364 * -SEQEN
365 * And following pins must be pulled low:
366 * -WR/BURST
367 * -DB4/SER1W
369 static const struct iio_chan_spec ad7616_channels[] = {
370 IIO_CHAN_SOFT_TIMESTAMP(16),
371 AD7606_CHANNEL(0),
372 AD7606_CHANNEL(1),
373 AD7606_CHANNEL(2),
374 AD7606_CHANNEL(3),
375 AD7606_CHANNEL(4),
376 AD7606_CHANNEL(5),
377 AD7606_CHANNEL(6),
378 AD7606_CHANNEL(7),
379 AD7606_CHANNEL(8),
380 AD7606_CHANNEL(9),
381 AD7606_CHANNEL(10),
382 AD7606_CHANNEL(11),
383 AD7606_CHANNEL(12),
384 AD7606_CHANNEL(13),
385 AD7606_CHANNEL(14),
386 AD7606_CHANNEL(15),
389 static const struct ad7606_chip_info ad7606_chip_info_tbl[] = {
390 /* More devices added in future */
391 [ID_AD7605_4] = {
392 .channels = ad7605_channels,
393 .num_channels = 5,
395 [ID_AD7606_8] = {
396 .channels = ad7606_channels,
397 .num_channels = 9,
398 .oversampling_avail = ad7606_oversampling_avail,
399 .oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail),
401 [ID_AD7606_6] = {
402 .channels = ad7606_channels,
403 .num_channels = 7,
404 .oversampling_avail = ad7606_oversampling_avail,
405 .oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail),
407 [ID_AD7606_4] = {
408 .channels = ad7606_channels,
409 .num_channels = 5,
410 .oversampling_avail = ad7606_oversampling_avail,
411 .oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail),
413 [ID_AD7606B] = {
414 .channels = ad7606_channels,
415 .num_channels = 9,
416 .oversampling_avail = ad7606_oversampling_avail,
417 .oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail),
419 [ID_AD7616] = {
420 .channels = ad7616_channels,
421 .num_channels = 17,
422 .oversampling_avail = ad7616_oversampling_avail,
423 .oversampling_num = ARRAY_SIZE(ad7616_oversampling_avail),
424 .os_req_reset = true,
425 .init_delay_ms = 15,
429 static int ad7606_request_gpios(struct ad7606_state *st)
431 struct device *dev = st->dev;
433 st->gpio_convst = devm_gpiod_get(dev, "adi,conversion-start",
434 GPIOD_OUT_LOW);
435 if (IS_ERR(st->gpio_convst))
436 return PTR_ERR(st->gpio_convst);
438 st->gpio_reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
439 if (IS_ERR(st->gpio_reset))
440 return PTR_ERR(st->gpio_reset);
442 st->gpio_range = devm_gpiod_get_optional(dev, "adi,range",
443 GPIOD_OUT_LOW);
444 if (IS_ERR(st->gpio_range))
445 return PTR_ERR(st->gpio_range);
447 st->gpio_standby = devm_gpiod_get_optional(dev, "standby",
448 GPIOD_OUT_HIGH);
449 if (IS_ERR(st->gpio_standby))
450 return PTR_ERR(st->gpio_standby);
452 st->gpio_frstdata = devm_gpiod_get_optional(dev, "adi,first-data",
453 GPIOD_IN);
454 if (IS_ERR(st->gpio_frstdata))
455 return PTR_ERR(st->gpio_frstdata);
457 if (!st->chip_info->oversampling_num)
458 return 0;
460 st->gpio_os = devm_gpiod_get_array_optional(dev,
461 "adi,oversampling-ratio",
462 GPIOD_OUT_LOW);
463 return PTR_ERR_OR_ZERO(st->gpio_os);
467 * The BUSY signal indicates when conversions are in progress, so when a rising
468 * edge of CONVST is applied, BUSY goes logic high and transitions low at the
469 * end of the entire conversion process. The falling edge of the BUSY signal
470 * triggers this interrupt.
472 static irqreturn_t ad7606_interrupt(int irq, void *dev_id)
474 struct iio_dev *indio_dev = dev_id;
475 struct ad7606_state *st = iio_priv(indio_dev);
477 if (iio_buffer_enabled(indio_dev)) {
478 gpiod_set_value(st->gpio_convst, 0);
479 iio_trigger_poll_chained(st->trig);
480 } else {
481 complete(&st->completion);
484 return IRQ_HANDLED;
487 static int ad7606_validate_trigger(struct iio_dev *indio_dev,
488 struct iio_trigger *trig)
490 struct ad7606_state *st = iio_priv(indio_dev);
492 if (st->trig != trig)
493 return -EINVAL;
495 return 0;
498 static int ad7606_buffer_postenable(struct iio_dev *indio_dev)
500 struct ad7606_state *st = iio_priv(indio_dev);
502 iio_triggered_buffer_postenable(indio_dev);
503 gpiod_set_value(st->gpio_convst, 1);
505 return 0;
508 static int ad7606_buffer_predisable(struct iio_dev *indio_dev)
510 struct ad7606_state *st = iio_priv(indio_dev);
512 gpiod_set_value(st->gpio_convst, 0);
514 return iio_triggered_buffer_predisable(indio_dev);
517 static const struct iio_buffer_setup_ops ad7606_buffer_ops = {
518 .postenable = &ad7606_buffer_postenable,
519 .predisable = &ad7606_buffer_predisable,
522 static const struct iio_info ad7606_info_no_os_or_range = {
523 .read_raw = &ad7606_read_raw,
524 .validate_trigger = &ad7606_validate_trigger,
527 static const struct iio_info ad7606_info_os_and_range = {
528 .read_raw = &ad7606_read_raw,
529 .write_raw = &ad7606_write_raw,
530 .attrs = &ad7606_attribute_group_os_and_range,
531 .validate_trigger = &ad7606_validate_trigger,
534 static const struct iio_info ad7606_info_os_range_and_debug = {
535 .read_raw = &ad7606_read_raw,
536 .write_raw = &ad7606_write_raw,
537 .debugfs_reg_access = &ad7606_reg_access,
538 .attrs = &ad7606_attribute_group_os_and_range,
539 .validate_trigger = &ad7606_validate_trigger,
542 static const struct iio_info ad7606_info_os = {
543 .read_raw = &ad7606_read_raw,
544 .write_raw = &ad7606_write_raw,
545 .attrs = &ad7606_attribute_group_os,
546 .validate_trigger = &ad7606_validate_trigger,
549 static const struct iio_info ad7606_info_range = {
550 .read_raw = &ad7606_read_raw,
551 .write_raw = &ad7606_write_raw,
552 .attrs = &ad7606_attribute_group_range,
553 .validate_trigger = &ad7606_validate_trigger,
556 static const struct iio_trigger_ops ad7606_trigger_ops = {
557 .validate_device = iio_trigger_validate_own_device,
560 static void ad7606_regulator_disable(void *data)
562 struct ad7606_state *st = data;
564 regulator_disable(st->reg);
567 int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
568 const char *name, unsigned int id,
569 const struct ad7606_bus_ops *bops)
571 struct ad7606_state *st;
572 int ret;
573 struct iio_dev *indio_dev;
575 indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
576 if (!indio_dev)
577 return -ENOMEM;
579 st = iio_priv(indio_dev);
580 dev_set_drvdata(dev, indio_dev);
582 st->dev = dev;
583 mutex_init(&st->lock);
584 st->bops = bops;
585 st->base_address = base_address;
586 /* tied to logic low, analog input range is +/- 5V */
587 st->range[0] = 0;
588 st->oversampling = 1;
589 st->scale_avail = ad7606_scale_avail;
590 st->num_scales = ARRAY_SIZE(ad7606_scale_avail);
592 st->reg = devm_regulator_get(dev, "avcc");
593 if (IS_ERR(st->reg))
594 return PTR_ERR(st->reg);
596 ret = regulator_enable(st->reg);
597 if (ret) {
598 dev_err(dev, "Failed to enable specified AVcc supply\n");
599 return ret;
602 ret = devm_add_action_or_reset(dev, ad7606_regulator_disable, st);
603 if (ret)
604 return ret;
606 st->chip_info = &ad7606_chip_info_tbl[id];
608 if (st->chip_info->oversampling_num) {
609 st->oversampling_avail = st->chip_info->oversampling_avail;
610 st->num_os_ratios = st->chip_info->oversampling_num;
613 ret = ad7606_request_gpios(st);
614 if (ret)
615 return ret;
617 indio_dev->dev.parent = dev;
618 if (st->gpio_os) {
619 if (st->gpio_range)
620 indio_dev->info = &ad7606_info_os_and_range;
621 else
622 indio_dev->info = &ad7606_info_os;
623 } else {
624 if (st->gpio_range)
625 indio_dev->info = &ad7606_info_range;
626 else
627 indio_dev->info = &ad7606_info_no_os_or_range;
629 indio_dev->modes = INDIO_DIRECT_MODE;
630 indio_dev->name = name;
631 indio_dev->channels = st->chip_info->channels;
632 indio_dev->num_channels = st->chip_info->num_channels;
634 init_completion(&st->completion);
636 ret = ad7606_reset(st);
637 if (ret)
638 dev_warn(st->dev, "failed to RESET: no RESET GPIO specified\n");
640 /* AD7616 requires al least 15ms to reconfigure after a reset */
641 if (st->chip_info->init_delay_ms) {
642 if (msleep_interruptible(st->chip_info->init_delay_ms))
643 return -ERESTARTSYS;
646 st->write_scale = ad7606_write_scale_hw;
647 st->write_os = ad7606_write_os_hw;
649 if (st->bops->sw_mode_config)
650 st->sw_mode_en = device_property_present(st->dev,
651 "adi,sw-mode");
653 if (st->sw_mode_en) {
654 /* Scale of 0.076293 is only available in sw mode */
655 st->scale_avail = ad7616_sw_scale_avail;
656 st->num_scales = ARRAY_SIZE(ad7616_sw_scale_avail);
658 /* After reset, in software mode, ±10 V is set by default */
659 memset32(st->range, 2, ARRAY_SIZE(st->range));
660 indio_dev->info = &ad7606_info_os_range_and_debug;
662 ret = st->bops->sw_mode_config(indio_dev);
663 if (ret < 0)
664 return ret;
667 st->trig = devm_iio_trigger_alloc(dev, "%s-dev%d",
668 indio_dev->name, indio_dev->id);
669 if (!st->trig)
670 return -ENOMEM;
672 st->trig->ops = &ad7606_trigger_ops;
673 st->trig->dev.parent = dev;
674 iio_trigger_set_drvdata(st->trig, indio_dev);
675 ret = devm_iio_trigger_register(dev, st->trig);
676 if (ret)
677 return ret;
679 indio_dev->trig = iio_trigger_get(st->trig);
681 ret = devm_request_threaded_irq(dev, irq,
682 NULL,
683 &ad7606_interrupt,
684 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
685 name, indio_dev);
686 if (ret)
687 return ret;
689 ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
690 &iio_pollfunc_store_time,
691 &ad7606_trigger_handler,
692 &ad7606_buffer_ops);
693 if (ret)
694 return ret;
696 return devm_iio_device_register(dev, indio_dev);
698 EXPORT_SYMBOL_GPL(ad7606_probe);
700 #ifdef CONFIG_PM_SLEEP
702 static int ad7606_suspend(struct device *dev)
704 struct iio_dev *indio_dev = dev_get_drvdata(dev);
705 struct ad7606_state *st = iio_priv(indio_dev);
707 if (st->gpio_standby) {
708 gpiod_set_value(st->gpio_range, 1);
709 gpiod_set_value(st->gpio_standby, 0);
712 return 0;
715 static int ad7606_resume(struct device *dev)
717 struct iio_dev *indio_dev = dev_get_drvdata(dev);
718 struct ad7606_state *st = iio_priv(indio_dev);
720 if (st->gpio_standby) {
721 gpiod_set_value(st->gpio_range, st->range[0]);
722 gpiod_set_value(st->gpio_standby, 1);
723 ad7606_reset(st);
726 return 0;
729 SIMPLE_DEV_PM_OPS(ad7606_pm_ops, ad7606_suspend, ad7606_resume);
730 EXPORT_SYMBOL_GPL(ad7606_pm_ops);
732 #endif
734 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
735 MODULE_DESCRIPTION("Analog Devices AD7606 ADC");
736 MODULE_LICENSE("GPL v2");