1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Driver for the Diolan DLN-2 USB-ADC adapter
4 *
5 * Copyright (c) 2017 Jack Andersen
6 */
7
8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/types.h>
11#include <linux/platform_device.h>
12#include <linux/mfd/dln2.h>
13
14#include <linux/iio/iio.h>
15#include <linux/iio/sysfs.h>
16#include <linux/iio/trigger.h>
17#include <linux/iio/trigger_consumer.h>
18#include <linux/iio/triggered_buffer.h>
19#include <linux/iio/buffer.h>
20#include <linux/iio/kfifo_buf.h>
21
22#define DLN2_ADC_MOD_NAME "dln2-adc"
23
24#define DLN2_ADC_ID 0x06
25
26#define DLN2_ADC_GET_CHANNEL_COUNT DLN2_CMD(0x01, DLN2_ADC_ID)
27#define DLN2_ADC_ENABLE DLN2_CMD(0x02, DLN2_ADC_ID)
28#define DLN2_ADC_DISABLE DLN2_CMD(0x03, DLN2_ADC_ID)
29#define DLN2_ADC_CHANNEL_ENABLE DLN2_CMD(0x05, DLN2_ADC_ID)
30#define DLN2_ADC_CHANNEL_DISABLE DLN2_CMD(0x06, DLN2_ADC_ID)
31#define DLN2_ADC_SET_RESOLUTION DLN2_CMD(0x08, DLN2_ADC_ID)
32#define DLN2_ADC_CHANNEL_GET_VAL DLN2_CMD(0x0A, DLN2_ADC_ID)
33#define DLN2_ADC_CHANNEL_GET_ALL_VAL DLN2_CMD(0x0B, DLN2_ADC_ID)
34#define DLN2_ADC_CHANNEL_SET_CFG DLN2_CMD(0x0C, DLN2_ADC_ID)
35#define DLN2_ADC_CHANNEL_GET_CFG DLN2_CMD(0x0D, DLN2_ADC_ID)
36#define DLN2_ADC_CONDITION_MET_EV DLN2_CMD(0x10, DLN2_ADC_ID)
37
38#define DLN2_ADC_EVENT_NONE 0
39#define DLN2_ADC_EVENT_BELOW 1
40#define DLN2_ADC_EVENT_LEVEL_ABOVE 2
41#define DLN2_ADC_EVENT_OUTSIDE 3
42#define DLN2_ADC_EVENT_INSIDE 4
43#define DLN2_ADC_EVENT_ALWAYS 5
44
45#define DLN2_ADC_MAX_CHANNELS 8
46#define DLN2_ADC_DATA_BITS 10
47
48/*
49 * Plays similar role to iio_demux_table in subsystem core; except allocated
50 * in a fixed 8-element array.
51 */
52struct dln2_adc_demux_table {
53 unsigned int from;
54 unsigned int to;
55 unsigned int length;
56};
57
58struct dln2_adc {
59 struct platform_device *pdev;
60 struct iio_chan_spec iio_channels[DLN2_ADC_MAX_CHANNELS + 1];
61 int port, trigger_chan;
62 struct iio_trigger *trig;
63 struct mutex mutex;
64 /* Cached sample period in milliseconds */
65 unsigned int sample_period;
66 /* Demux table */
67 unsigned int demux_count;
68 struct dln2_adc_demux_table demux[DLN2_ADC_MAX_CHANNELS];
69 /* Precomputed timestamp padding offset and length */
70 unsigned int ts_pad_offset, ts_pad_length;
71};
72
73struct dln2_adc_port_chan {
74 u8 port;
75 u8 chan;
76};
77
78struct dln2_adc_get_all_vals {
79 __le16 channel_mask;
80 __le16 values[DLN2_ADC_MAX_CHANNELS];
81};
82
83static void dln2_adc_add_demux(struct dln2_adc *dln2,
84 unsigned int in_loc, unsigned int out_loc,
85 unsigned int length)
86{
87 struct dln2_adc_demux_table *p = dln2->demux_count ?
88 &dln2->demux[dln2->demux_count - 1] : NULL;
89
90 if (p && p->from + p->length == in_loc &&
91 p->to + p->length == out_loc) {
92 p->length += length;
93 } else if (dln2->demux_count < DLN2_ADC_MAX_CHANNELS) {
94 p = &dln2->demux[dln2->demux_count++];
95 p->from = in_loc;
96 p->to = out_loc;
97 p->length = length;
98 }
99}
100
101static void dln2_adc_update_demux(struct dln2_adc *dln2)
102{
103 int in_ind = -1, out_ind;
104 unsigned int in_loc = 0, out_loc = 0;
105 struct iio_dev *indio_dev = platform_get_drvdata(pdev: dln2->pdev);
106
107 /* Clear out any old demux */
108 dln2->demux_count = 0;
109
110 /* Optimize all 8-channels case */
111 if (indio_dev->masklength &&
112 (*indio_dev->active_scan_mask & 0xff) == 0xff) {
113 dln2_adc_add_demux(dln2, in_loc: 0, out_loc: 0, length: 16);
114 dln2->ts_pad_offset = 0;
115 dln2->ts_pad_length = 0;
116 return;
117 }
118
119 /* Build demux table from fixed 8-channels to active_scan_mask */
120 for_each_set_bit(out_ind,
121 indio_dev->active_scan_mask,
122 indio_dev->masklength) {
123 /* Handle timestamp separately */
124 if (out_ind == DLN2_ADC_MAX_CHANNELS)
125 break;
126 for (++in_ind; in_ind != out_ind; ++in_ind)
127 in_loc += 2;
128 dln2_adc_add_demux(dln2, in_loc, out_loc, length: 2);
129 out_loc += 2;
130 in_loc += 2;
131 }
132
133 if (indio_dev->scan_timestamp) {
134 size_t ts_offset = indio_dev->scan_bytes / sizeof(int64_t) - 1;
135
136 dln2->ts_pad_offset = out_loc;
137 dln2->ts_pad_length = ts_offset * sizeof(int64_t) - out_loc;
138 } else {
139 dln2->ts_pad_offset = 0;
140 dln2->ts_pad_length = 0;
141 }
142}
143
144static int dln2_adc_get_chan_count(struct dln2_adc *dln2)
145{
146 int ret;
147 u8 port = dln2->port;
148 u8 count;
149 int olen = sizeof(count);
150
151 ret = dln2_transfer(pdev: dln2->pdev, DLN2_ADC_GET_CHANNEL_COUNT,
152 obuf: &port, obuf_len: sizeof(port), ibuf: &count, ibuf_len: &olen);
153 if (ret < 0) {
154 dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__);
155 return ret;
156 }
157 if (olen < sizeof(count))
158 return -EPROTO;
159
160 return count;
161}
162
163static int dln2_adc_set_port_resolution(struct dln2_adc *dln2)
164{
165 int ret;
166 struct dln2_adc_port_chan port_chan = {
167 .port = dln2->port,
168 .chan = DLN2_ADC_DATA_BITS,
169 };
170
171 ret = dln2_transfer_tx(pdev: dln2->pdev, DLN2_ADC_SET_RESOLUTION,
172 obuf: &port_chan, obuf_len: sizeof(port_chan));
173 if (ret < 0)
174 dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__);
175
176 return ret;
177}
178
179static int dln2_adc_set_chan_enabled(struct dln2_adc *dln2,
180 int channel, bool enable)
181{
182 int ret;
183 struct dln2_adc_port_chan port_chan = {
184 .port = dln2->port,
185 .chan = channel,
186 };
187 u16 cmd = enable ? DLN2_ADC_CHANNEL_ENABLE : DLN2_ADC_CHANNEL_DISABLE;
188
189 ret = dln2_transfer_tx(pdev: dln2->pdev, cmd, obuf: &port_chan, obuf_len: sizeof(port_chan));
190 if (ret < 0)
191 dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__);
192
193 return ret;
194}
195
196static int dln2_adc_set_port_enabled(struct dln2_adc *dln2, bool enable,
197 u16 *conflict_out)
198{
199 int ret;
200 u8 port = dln2->port;
201 __le16 conflict;
202 int olen = sizeof(conflict);
203 u16 cmd = enable ? DLN2_ADC_ENABLE : DLN2_ADC_DISABLE;
204
205 if (conflict_out)
206 *conflict_out = 0;
207
208 ret = dln2_transfer(pdev: dln2->pdev, cmd, obuf: &port, obuf_len: sizeof(port),
209 ibuf: &conflict, ibuf_len: &olen);
210 if (ret < 0) {
211 dev_dbg(&dln2->pdev->dev, "Problem in %s(%d)\n",
212 __func__, (int)enable);
213 if (conflict_out && enable && olen >= sizeof(conflict))
214 *conflict_out = le16_to_cpu(conflict);
215 return ret;
216 }
217 if (enable && olen < sizeof(conflict))
218 return -EPROTO;
219
220 return ret;
221}
222
223static int dln2_adc_set_chan_period(struct dln2_adc *dln2,
224 unsigned int channel, unsigned int period)
225{
226 int ret;
227 struct {
228 struct dln2_adc_port_chan port_chan;
229 __u8 type;
230 __le16 period;
231 __le16 low;
232 __le16 high;
233 } __packed set_cfg = {
234 .port_chan.port = dln2->port,
235 .port_chan.chan = channel,
236 .type = period ? DLN2_ADC_EVENT_ALWAYS : DLN2_ADC_EVENT_NONE,
237 .period = cpu_to_le16(period)
238 };
239
240 ret = dln2_transfer_tx(pdev: dln2->pdev, DLN2_ADC_CHANNEL_SET_CFG,
241 obuf: &set_cfg, obuf_len: sizeof(set_cfg));
242 if (ret < 0)
243 dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__);
244
245 return ret;
246}
247
248static int dln2_adc_read(struct dln2_adc *dln2, unsigned int channel)
249{
250 int ret, i;
251 u16 conflict;
252 __le16 value;
253 int olen = sizeof(value);
254 struct dln2_adc_port_chan port_chan = {
255 .port = dln2->port,
256 .chan = channel,
257 };
258
259 ret = dln2_adc_set_chan_enabled(dln2, channel, enable: true);
260 if (ret < 0)
261 return ret;
262
263 ret = dln2_adc_set_port_enabled(dln2, enable: true, conflict_out: &conflict);
264 if (ret < 0) {
265 if (conflict) {
266 dev_err(&dln2->pdev->dev,
267 "ADC pins conflict with mask %04X\n",
268 (int)conflict);
269 ret = -EBUSY;
270 }
271 goto disable_chan;
272 }
273
274 /*
275 * Call GET_VAL twice due to initial zero-return immediately after
276 * enabling channel.
277 */
278 for (i = 0; i < 2; ++i) {
279 ret = dln2_transfer(pdev: dln2->pdev, DLN2_ADC_CHANNEL_GET_VAL,
280 obuf: &port_chan, obuf_len: sizeof(port_chan),
281 ibuf: &value, ibuf_len: &olen);
282 if (ret < 0) {
283 dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__);
284 goto disable_port;
285 }
286 if (olen < sizeof(value)) {
287 ret = -EPROTO;
288 goto disable_port;
289 }
290 }
291
292 ret = le16_to_cpu(value);
293
294disable_port:
295 dln2_adc_set_port_enabled(dln2, enable: false, NULL);
296disable_chan:
297 dln2_adc_set_chan_enabled(dln2, channel, enable: false);
298
299 return ret;
300}
301
302static int dln2_adc_read_all(struct dln2_adc *dln2,
303 struct dln2_adc_get_all_vals *get_all_vals)
304{
305 int ret;
306 __u8 port = dln2->port;
307 int olen = sizeof(*get_all_vals);
308
309 ret = dln2_transfer(pdev: dln2->pdev, DLN2_ADC_CHANNEL_GET_ALL_VAL,
310 obuf: &port, obuf_len: sizeof(port), ibuf: get_all_vals, ibuf_len: &olen);
311 if (ret < 0) {
312 dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__);
313 return ret;
314 }
315 if (olen < sizeof(*get_all_vals))
316 return -EPROTO;
317
318 return ret;
319}
320
321static int dln2_adc_read_raw(struct iio_dev *indio_dev,
322 struct iio_chan_spec const *chan,
323 int *val,
324 int *val2,
325 long mask)
326{
327 int ret;
328 unsigned int microhertz;
329 struct dln2_adc *dln2 = iio_priv(indio_dev);
330
331 switch (mask) {
332 case IIO_CHAN_INFO_RAW:
333 ret = iio_device_claim_direct_mode(indio_dev);
334 if (ret < 0)
335 return ret;
336
337 mutex_lock(&dln2->mutex);
338 ret = dln2_adc_read(dln2, channel: chan->channel);
339 mutex_unlock(lock: &dln2->mutex);
340
341 iio_device_release_direct_mode(indio_dev);
342
343 if (ret < 0)
344 return ret;
345
346 *val = ret;
347 return IIO_VAL_INT;
348
349 case IIO_CHAN_INFO_SCALE:
350 /*
351 * Voltage reference is fixed at 3.3v
352 * 3.3 / (1 << 10) * 1000000000
353 */
354 *val = 0;
355 *val2 = 3222656;
356 return IIO_VAL_INT_PLUS_NANO;
357
358 case IIO_CHAN_INFO_SAMP_FREQ:
359 if (dln2->sample_period) {
360 microhertz = 1000000000 / dln2->sample_period;
361 *val = microhertz / 1000000;
362 *val2 = microhertz % 1000000;
363 } else {
364 *val = 0;
365 *val2 = 0;
366 }
367
368 return IIO_VAL_INT_PLUS_MICRO;
369
370 default:
371 return -EINVAL;
372 }
373}
374
375static int dln2_adc_write_raw(struct iio_dev *indio_dev,
376 struct iio_chan_spec const *chan,
377 int val,
378 int val2,
379 long mask)
380{
381 int ret;
382 unsigned int microhertz;
383 struct dln2_adc *dln2 = iio_priv(indio_dev);
384
385 switch (mask) {
386 case IIO_CHAN_INFO_SAMP_FREQ:
387 microhertz = 1000000 * val + val2;
388
389 mutex_lock(&dln2->mutex);
390
391 dln2->sample_period =
392 microhertz ? 1000000000 / microhertz : UINT_MAX;
393 if (dln2->sample_period > 65535) {
394 dln2->sample_period = 65535;
395 dev_warn(&dln2->pdev->dev,
396 "clamping period to 65535ms\n");
397 }
398
399 /*
400 * The first requested channel is arbitrated as a shared
401 * trigger source, so only one event is registered with the
402 * DLN. The event handler will then read all enabled channel
403 * values using DLN2_ADC_CHANNEL_GET_ALL_VAL to maintain
404 * synchronization between ADC readings.
405 */
406 if (dln2->trigger_chan != -1)
407 ret = dln2_adc_set_chan_period(dln2,
408 channel: dln2->trigger_chan, period: dln2->sample_period);
409 else
410 ret = 0;
411
412 mutex_unlock(lock: &dln2->mutex);
413
414 return ret;
415
416 default:
417 return -EINVAL;
418 }
419}
420
421static int dln2_update_scan_mode(struct iio_dev *indio_dev,
422 const unsigned long *scan_mask)
423{
424 struct dln2_adc *dln2 = iio_priv(indio_dev);
425 int chan_count = indio_dev->num_channels - 1;
426 int ret, i, j;
427
428 mutex_lock(&dln2->mutex);
429
430 for (i = 0; i < chan_count; ++i) {
431 ret = dln2_adc_set_chan_enabled(dln2, channel: i,
432 test_bit(i, scan_mask));
433 if (ret < 0) {
434 for (j = 0; j < i; ++j)
435 dln2_adc_set_chan_enabled(dln2, channel: j, enable: false);
436 mutex_unlock(lock: &dln2->mutex);
437 dev_err(&dln2->pdev->dev,
438 "Unable to enable ADC channel %d\n", i);
439 return -EBUSY;
440 }
441 }
442
443 dln2_adc_update_demux(dln2);
444
445 mutex_unlock(lock: &dln2->mutex);
446
447 return 0;
448}
449
450#define DLN2_ADC_CHAN(lval, idx) { \
451 lval.type = IIO_VOLTAGE; \
452 lval.channel = idx; \
453 lval.indexed = 1; \
454 lval.info_mask_separate = BIT(IIO_CHAN_INFO_RAW); \
455 lval.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SCALE) | \
456 BIT(IIO_CHAN_INFO_SAMP_FREQ); \
457 lval.scan_index = idx; \
458 lval.scan_type.sign = 'u'; \
459 lval.scan_type.realbits = DLN2_ADC_DATA_BITS; \
460 lval.scan_type.storagebits = 16; \
461 lval.scan_type.endianness = IIO_LE; \
462}
463
464/* Assignment version of IIO_CHAN_SOFT_TIMESTAMP */
465#define IIO_CHAN_SOFT_TIMESTAMP_ASSIGN(lval, _si) { \
466 lval.type = IIO_TIMESTAMP; \
467 lval.channel = -1; \
468 lval.scan_index = _si; \
469 lval.scan_type.sign = 's'; \
470 lval.scan_type.realbits = 64; \
471 lval.scan_type.storagebits = 64; \
472}
473
474static const struct iio_info dln2_adc_info = {
475 .read_raw = dln2_adc_read_raw,
476 .write_raw = dln2_adc_write_raw,
477 .update_scan_mode = dln2_update_scan_mode,
478};
479
480static irqreturn_t dln2_adc_trigger_h(int irq, void *p)
481{
482 struct iio_poll_func *pf = p;
483 struct iio_dev *indio_dev = pf->indio_dev;
484 struct {
485 __le16 values[DLN2_ADC_MAX_CHANNELS];
486 int64_t timestamp_space;
487 } data;
488 struct dln2_adc_get_all_vals dev_data;
489 struct dln2_adc *dln2 = iio_priv(indio_dev);
490 const struct dln2_adc_demux_table *t;
491 int ret, i;
492
493 mutex_lock(&dln2->mutex);
494 ret = dln2_adc_read_all(dln2, get_all_vals: &dev_data);
495 mutex_unlock(lock: &dln2->mutex);
496 if (ret < 0)
497 goto done;
498
499 /* Demux operation */
500 for (i = 0; i < dln2->demux_count; ++i) {
501 t = &dln2->demux[i];
502 memcpy((void *)data.values + t->to,
503 (void *)dev_data.values + t->from, t->length);
504 }
505
506 /* Zero padding space between values and timestamp */
507 if (dln2->ts_pad_length)
508 memset((void *)data.values + dln2->ts_pad_offset,
509 0, dln2->ts_pad_length);
510
511 iio_push_to_buffers_with_timestamp(indio_dev, data: &data,
512 timestamp: iio_get_time_ns(indio_dev));
513
514done:
515 iio_trigger_notify_done(trig: indio_dev->trig);
516 return IRQ_HANDLED;
517}
518
519static int dln2_adc_triggered_buffer_postenable(struct iio_dev *indio_dev)
520{
521 int ret;
522 struct dln2_adc *dln2 = iio_priv(indio_dev);
523 u16 conflict;
524 unsigned int trigger_chan;
525
526 mutex_lock(&dln2->mutex);
527
528 /* Enable ADC */
529 ret = dln2_adc_set_port_enabled(dln2, enable: true, conflict_out: &conflict);
530 if (ret < 0) {
531 mutex_unlock(lock: &dln2->mutex);
532 dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__);
533 if (conflict) {
534 dev_err(&dln2->pdev->dev,
535 "ADC pins conflict with mask %04X\n",
536 (int)conflict);
537 ret = -EBUSY;
538 }
539 return ret;
540 }
541
542 /* Assign trigger channel based on first enabled channel */
543 trigger_chan = find_first_bit(addr: indio_dev->active_scan_mask,
544 size: indio_dev->masklength);
545 if (trigger_chan < DLN2_ADC_MAX_CHANNELS) {
546 dln2->trigger_chan = trigger_chan;
547 ret = dln2_adc_set_chan_period(dln2, channel: dln2->trigger_chan,
548 period: dln2->sample_period);
549 mutex_unlock(lock: &dln2->mutex);
550 if (ret < 0) {
551 dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__);
552 return ret;
553 }
554 } else {
555 dln2->trigger_chan = -1;
556 mutex_unlock(lock: &dln2->mutex);
557 }
558
559 return 0;
560}
561
562static int dln2_adc_triggered_buffer_predisable(struct iio_dev *indio_dev)
563{
564 int ret;
565 struct dln2_adc *dln2 = iio_priv(indio_dev);
566
567 mutex_lock(&dln2->mutex);
568
569 /* Disable trigger channel */
570 if (dln2->trigger_chan != -1) {
571 dln2_adc_set_chan_period(dln2, channel: dln2->trigger_chan, period: 0);
572 dln2->trigger_chan = -1;
573 }
574
575 /* Disable ADC */
576 ret = dln2_adc_set_port_enabled(dln2, enable: false, NULL);
577
578 mutex_unlock(lock: &dln2->mutex);
579 if (ret < 0)
580 dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__);
581
582 return ret;
583}
584
585static const struct iio_buffer_setup_ops dln2_adc_buffer_setup_ops = {
586 .postenable = dln2_adc_triggered_buffer_postenable,
587 .predisable = dln2_adc_triggered_buffer_predisable,
588};
589
590static void dln2_adc_event(struct platform_device *pdev, u16 echo,
591 const void *data, int len)
592{
593 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
594 struct dln2_adc *dln2 = iio_priv(indio_dev);
595
596 /* Called via URB completion handler */
597 iio_trigger_poll(trig: dln2->trig);
598}
599
600static int dln2_adc_probe(struct platform_device *pdev)
601{
602 struct device *dev = &pdev->dev;
603 struct dln2_adc *dln2;
604 struct dln2_platform_data *pdata = dev_get_platdata(dev: &pdev->dev);
605 struct iio_dev *indio_dev;
606 int i, ret, chans;
607
608 indio_dev = devm_iio_device_alloc(parent: dev, sizeof_priv: sizeof(*dln2));
609 if (!indio_dev) {
610 dev_err(dev, "failed allocating iio device\n");
611 return -ENOMEM;
612 }
613
614 dln2 = iio_priv(indio_dev);
615 dln2->pdev = pdev;
616 dln2->port = pdata->port;
617 dln2->trigger_chan = -1;
618 mutex_init(&dln2->mutex);
619
620 platform_set_drvdata(pdev, data: indio_dev);
621
622 ret = dln2_adc_set_port_resolution(dln2);
623 if (ret < 0) {
624 dev_err(dev, "failed to set ADC resolution to 10 bits\n");
625 return ret;
626 }
627
628 chans = dln2_adc_get_chan_count(dln2);
629 if (chans < 0) {
630 dev_err(dev, "failed to get channel count: %d\n", chans);
631 return chans;
632 }
633 if (chans > DLN2_ADC_MAX_CHANNELS) {
634 chans = DLN2_ADC_MAX_CHANNELS;
635 dev_warn(dev, "clamping channels to %d\n",
636 DLN2_ADC_MAX_CHANNELS);
637 }
638
639 for (i = 0; i < chans; ++i)
640 DLN2_ADC_CHAN(dln2->iio_channels[i], i)
641 IIO_CHAN_SOFT_TIMESTAMP_ASSIGN(dln2->iio_channels[i], i);
642
643 indio_dev->name = DLN2_ADC_MOD_NAME;
644 indio_dev->info = &dln2_adc_info;
645 indio_dev->modes = INDIO_DIRECT_MODE;
646 indio_dev->channels = dln2->iio_channels;
647 indio_dev->num_channels = chans + 1;
648 indio_dev->setup_ops = &dln2_adc_buffer_setup_ops;
649
650 dln2->trig = devm_iio_trigger_alloc(dev, "%s-dev%d",
651 indio_dev->name,
652 iio_device_id(indio_dev));
653 if (!dln2->trig) {
654 dev_err(dev, "failed to allocate trigger\n");
655 return -ENOMEM;
656 }
657 iio_trigger_set_drvdata(trig: dln2->trig, data: dln2);
658 ret = devm_iio_trigger_register(dev, trig_info: dln2->trig);
659 if (ret) {
660 dev_err(dev, "failed to register trigger: %d\n", ret);
661 return ret;
662 }
663 iio_trigger_set_immutable(indio_dev, trig: dln2->trig);
664
665 ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
666 dln2_adc_trigger_h,
667 &dln2_adc_buffer_setup_ops);
668 if (ret) {
669 dev_err(dev, "failed to allocate triggered buffer: %d\n", ret);
670 return ret;
671 }
672
673 ret = dln2_register_event_cb(pdev, DLN2_ADC_CONDITION_MET_EV,
674 event_cb: dln2_adc_event);
675 if (ret) {
676 dev_err(dev, "failed to setup DLN2 periodic event: %d\n", ret);
677 return ret;
678 }
679
680 ret = iio_device_register(indio_dev);
681 if (ret) {
682 dev_err(dev, "failed to register iio device: %d\n", ret);
683 goto unregister_event;
684 }
685
686 return ret;
687
688unregister_event:
689 dln2_unregister_event_cb(pdev, DLN2_ADC_CONDITION_MET_EV);
690
691 return ret;
692}
693
694static void dln2_adc_remove(struct platform_device *pdev)
695{
696 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
697
698 iio_device_unregister(indio_dev);
699 dln2_unregister_event_cb(pdev, DLN2_ADC_CONDITION_MET_EV);
700}
701
702static struct platform_driver dln2_adc_driver = {
703 .driver.name = DLN2_ADC_MOD_NAME,
704 .probe = dln2_adc_probe,
705 .remove_new = dln2_adc_remove,
706};
707
708module_platform_driver(dln2_adc_driver);
709
710MODULE_AUTHOR("Jack Andersen <jackoalan@gmail.com");
711MODULE_DESCRIPTION("Driver for the Diolan DLN2 ADC interface");
712MODULE_LICENSE("GPL v2");
713MODULE_ALIAS("platform:dln2-adc");
714

source code of linux/drivers/iio/adc/dln2-adc.c