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