summaryrefslogtreecommitdiffstats
path: root/drivers/iio/adc/bcm_iproc_adc.c
blob: 7af59a4bbd8d428fcf27e6700b28ef5fd5c8cf56 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
/*
 * Copyright 2016 Broadcom
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2, as
 * published by the Free Software Foundation (the "GPL").
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License version 2 (GPLv2) for more details.
 *
 * You should have received a copy of the GNU General Public License
 * version 2 (GPLv2) along with this source code.
 */

#include <linux/module.h>
#include <linux/of.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>

#include <linux/iio/iio.h>

/* Below Register's are common to IPROC ADC and Touchscreen IP */
#define IPROC_REGCTL1			0x00
#define IPROC_REGCTL2			0x04
#define IPROC_INTERRUPT_THRES		0x08
#define IPROC_INTERRUPT_MASK		0x0c
#define IPROC_INTERRUPT_STATUS		0x10
#define IPROC_ANALOG_CONTROL		0x1c
#define IPROC_CONTROLLER_STATUS		0x14
#define IPROC_AUX_DATA			0x20
#define IPROC_SOFT_BYPASS_CONTROL	0x38
#define IPROC_SOFT_BYPASS_DATA		0x3C

/* IPROC ADC Channel register offsets */
#define IPROC_ADC_CHANNEL_REGCTL1		0x800
#define IPROC_ADC_CHANNEL_REGCTL2		0x804
#define IPROC_ADC_CHANNEL_STATUS		0x808
#define IPROC_ADC_CHANNEL_INTERRUPT_STATUS	0x80c
#define IPROC_ADC_CHANNEL_INTERRUPT_MASK	0x810
#define IPROC_ADC_CHANNEL_DATA			0x814
#define IPROC_ADC_CHANNEL_OFFSET		0x20

/* Bit definitions for IPROC_REGCTL2 */
#define IPROC_ADC_AUXIN_SCAN_ENA	BIT(0)
#define IPROC_ADC_PWR_LDO		BIT(5)
#define IPROC_ADC_PWR_ADC		BIT(4)
#define IPROC_ADC_PWR_BG		BIT(3)
#define IPROC_ADC_CONTROLLER_EN		BIT(17)

/* Bit definitions for IPROC_INTERRUPT_MASK and IPROC_INTERRUPT_STATUS */
#define IPROC_ADC_AUXDATA_RDY_INTR	BIT(3)
#define IPROC_ADC_INTR			9
#define IPROC_ADC_INTR_MASK		(0xFF << IPROC_ADC_INTR)

/* Bit definitions for IPROC_ANALOG_CONTROL */
#define IPROC_ADC_CHANNEL_SEL		11
#define IPROC_ADC_CHANNEL_SEL_MASK	(0x7 << IPROC_ADC_CHANNEL_SEL)

/* Bit definitions for IPROC_ADC_CHANNEL_REGCTL1 */
#define IPROC_ADC_CHANNEL_ROUNDS	0x2
#define IPROC_ADC_CHANNEL_ROUNDS_MASK	(0x3F << IPROC_ADC_CHANNEL_ROUNDS)
#define IPROC_ADC_CHANNEL_MODE		0x1
#define IPROC_ADC_CHANNEL_MODE_MASK	(0x1 << IPROC_ADC_CHANNEL_MODE)
#define IPROC_ADC_CHANNEL_MODE_TDM	0x1
#define IPROC_ADC_CHANNEL_MODE_SNAPSHOT 0x0
#define IPROC_ADC_CHANNEL_ENABLE	0x0
#define IPROC_ADC_CHANNEL_ENABLE_MASK	0x1

/* Bit definitions for IPROC_ADC_CHANNEL_REGCTL2 */
#define IPROC_ADC_CHANNEL_WATERMARK	0x0
#define IPROC_ADC_CHANNEL_WATERMARK_MASK \
		(0x3F << IPROC_ADC_CHANNEL_WATERMARK)

#define IPROC_ADC_WATER_MARK_LEVEL	0x1

/* Bit definitions for IPROC_ADC_CHANNEL_STATUS */
#define IPROC_ADC_CHANNEL_DATA_LOST		0x0
#define IPROC_ADC_CHANNEL_DATA_LOST_MASK	\
		(0x0 << IPROC_ADC_CHANNEL_DATA_LOST)
#define IPROC_ADC_CHANNEL_VALID_ENTERIES	0x1
#define IPROC_ADC_CHANNEL_VALID_ENTERIES_MASK	\
		(0xFF << IPROC_ADC_CHANNEL_VALID_ENTERIES)
#define IPROC_ADC_CHANNEL_TOTAL_ENTERIES	0x9
#define IPROC_ADC_CHANNEL_TOTAL_ENTERIES_MASK	\
		(0xFF << IPROC_ADC_CHANNEL_TOTAL_ENTERIES)

/* Bit definitions for IPROC_ADC_CHANNEL_INTERRUPT_MASK */
#define IPROC_ADC_CHANNEL_WTRMRK_INTR			0x0
#define IPROC_ADC_CHANNEL_WTRMRK_INTR_MASK		\
		(0x1 << IPROC_ADC_CHANNEL_WTRMRK_INTR)
#define IPROC_ADC_CHANNEL_FULL_INTR			0x1
#define IPROC_ADC_CHANNEL_FULL_INTR_MASK		\
		(0x1 << IPROC_ADC_IPROC_ADC_CHANNEL_FULL_INTR)
#define IPROC_ADC_CHANNEL_EMPTY_INTR			0x2
#define IPROC_ADC_CHANNEL_EMPTY_INTR_MASK		\
		(0x1 << IPROC_ADC_CHANNEL_EMPTY_INTR)

#define IPROC_ADC_WATER_MARK_INTR_ENABLE		0x1

/* Number of time to retry a set of the interrupt mask reg */
#define IPROC_ADC_INTMASK_RETRY_ATTEMPTS		10

#define IPROC_ADC_READ_TIMEOUT        (HZ*2)

#define iproc_adc_dbg_reg(dev, priv, reg) \
do { \
	u32 val; \
	regmap_read(priv->regmap, reg, &val); \
	dev_dbg(dev, "%20s= 0x%08x\n", #reg, val); \
} while (0)

struct iproc_adc_priv {
	struct regmap *regmap;
	struct clk *adc_clk;
	struct mutex mutex;
	int  irqno;
	int chan_val;
	int chan_id;
	struct completion completion;
};

static void iproc_adc_reg_dump(struct iio_dev *indio_dev)
{
	struct device *dev = &indio_dev->dev;
	struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);

	iproc_adc_dbg_reg(dev, adc_priv, IPROC_REGCTL1);
	iproc_adc_dbg_reg(dev, adc_priv, IPROC_REGCTL2);
	iproc_adc_dbg_reg(dev, adc_priv, IPROC_INTERRUPT_THRES);
	iproc_adc_dbg_reg(dev, adc_priv, IPROC_INTERRUPT_MASK);
	iproc_adc_dbg_reg(dev, adc_priv, IPROC_INTERRUPT_STATUS);
	iproc_adc_dbg_reg(dev, adc_priv, IPROC_CONTROLLER_STATUS);
	iproc_adc_dbg_reg(dev, adc_priv, IPROC_ANALOG_CONTROL);
	iproc_adc_dbg_reg(dev, adc_priv, IPROC_AUX_DATA);
	iproc_adc_dbg_reg(dev, adc_priv, IPROC_SOFT_BYPASS_CONTROL);
	iproc_adc_dbg_reg(dev, adc_priv, IPROC_SOFT_BYPASS_DATA);
}

static irqreturn_t iproc_adc_interrupt_thread(int irq, void *data)
{
	u32 channel_intr_status;
	u32 intr_status;
	u32 intr_mask;
	struct iio_dev *indio_dev = data;
	struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);

	/*
	 * This interrupt is shared with the touchscreen driver.
	 * Make sure this interrupt is intended for us.
	 * Handle only ADC channel specific interrupts.
	 */
	regmap_read(adc_priv->regmap, IPROC_INTERRUPT_STATUS, &intr_status);
	regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &intr_mask);
	intr_status = intr_status & intr_mask;
	channel_intr_status = (intr_status & IPROC_ADC_INTR_MASK) >>
				IPROC_ADC_INTR;
	if (channel_intr_status)
		return IRQ_WAKE_THREAD;

	return IRQ_NONE;
}

static irqreturn_t iproc_adc_interrupt_handler(int irq, void *data)
{
	irqreturn_t retval = IRQ_NONE;
	struct iproc_adc_priv *adc_priv;
	struct iio_dev *indio_dev = data;
	unsigned int valid_entries;
	u32 intr_status;
	u32 intr_channels;
	u32 channel_status;
	u32 ch_intr_status;

	adc_priv = iio_priv(indio_dev);

	regmap_read(adc_priv->regmap, IPROC_INTERRUPT_STATUS, &intr_status);
	dev_dbg(&indio_dev->dev, "iproc_adc_interrupt_handler(),INTRPT_STS:%x\n",
			intr_status);

	intr_channels = (intr_status & IPROC_ADC_INTR_MASK) >> IPROC_ADC_INTR;
	if (intr_channels) {
		regmap_read(adc_priv->regmap,
			    IPROC_ADC_CHANNEL_INTERRUPT_STATUS +
			    IPROC_ADC_CHANNEL_OFFSET * adc_priv->chan_id,
			    &ch_intr_status);

		if (ch_intr_status & IPROC_ADC_CHANNEL_WTRMRK_INTR_MASK) {
			regmap_read(adc_priv->regmap,
					IPROC_ADC_CHANNEL_STATUS +
					IPROC_ADC_CHANNEL_OFFSET *
					adc_priv->chan_id,
					&channel_status);

			valid_entries = ((channel_status &
				IPROC_ADC_CHANNEL_VALID_ENTERIES_MASK) >>
				IPROC_ADC_CHANNEL_VALID_ENTERIES);
			if (valid_entries >= 1) {
				regmap_read(adc_priv->regmap,
					IPROC_ADC_CHANNEL_DATA +
					IPROC_ADC_CHANNEL_OFFSET *
					adc_priv->chan_id,
					&adc_priv->chan_val);
				complete(&adc_priv->completion);
			} else {
				dev_err(&indio_dev->dev,
					"No data rcvd on channel %d\n",
					adc_priv->chan_id);
			}
			regmap_write(adc_priv->regmap,
					IPROC_ADC_CHANNEL_INTERRUPT_MASK +
					IPROC_ADC_CHANNEL_OFFSET *
					adc_priv->chan_id,
					(ch_intr_status &
					~(IPROC_ADC_CHANNEL_WTRMRK_INTR_MASK)));
		}
		regmap_write(adc_priv->regmap,
				IPROC_ADC_CHANNEL_INTERRUPT_STATUS +
				IPROC_ADC_CHANNEL_OFFSET * adc_priv->chan_id,
				ch_intr_status);
		regmap_write(adc_priv->regmap, IPROC_INTERRUPT_STATUS,
				intr_channels);
		retval = IRQ_HANDLED;
	}

	return retval;
}

static int iproc_adc_do_read(struct iio_dev *indio_dev,
			   int channel,
			   u16 *p_adc_data)
{
	int read_len = 0;
	u32 val;
	u32 mask;
	u32 val_check;
	int failed_cnt = 0;
	struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);

	mutex_lock(&adc_priv->mutex);

	/*
	 * After a read is complete the ADC interrupts will be disabled so
	 * we can assume this section of code is safe from interrupts.
	 */
	adc_priv->chan_val = -1;
	adc_priv->chan_id = channel;

	reinit_completion(&adc_priv->completion);
	/* Clear any pending interrupt */
	regmap_update_bits(adc_priv->regmap, IPROC_INTERRUPT_STATUS,
			IPROC_ADC_INTR_MASK | IPROC_ADC_AUXDATA_RDY_INTR,
			((0x0 << channel) << IPROC_ADC_INTR) |
			IPROC_ADC_AUXDATA_RDY_INTR);

	/* Configure channel for snapshot mode and enable  */
	val = (BIT(IPROC_ADC_CHANNEL_ROUNDS) |
		(IPROC_ADC_CHANNEL_MODE_SNAPSHOT << IPROC_ADC_CHANNEL_MODE) |
		(0x1 << IPROC_ADC_CHANNEL_ENABLE));

	mask = IPROC_ADC_CHANNEL_ROUNDS_MASK | IPROC_ADC_CHANNEL_MODE_MASK |
		IPROC_ADC_CHANNEL_ENABLE_MASK;
	regmap_update_bits(adc_priv->regmap, (IPROC_ADC_CHANNEL_REGCTL1 +
				IPROC_ADC_CHANNEL_OFFSET * channel),
				mask, val);

	/* Set the Watermark for a channel */
	regmap_update_bits(adc_priv->regmap, (IPROC_ADC_CHANNEL_REGCTL2 +
					IPROC_ADC_CHANNEL_OFFSET * channel),
					IPROC_ADC_CHANNEL_WATERMARK_MASK,
					0x1);

	/* Enable water mark interrupt */
	regmap_update_bits(adc_priv->regmap, (IPROC_ADC_CHANNEL_INTERRUPT_MASK +
					IPROC_ADC_CHANNEL_OFFSET *
					channel),
					IPROC_ADC_CHANNEL_WTRMRK_INTR_MASK,
					IPROC_ADC_WATER_MARK_INTR_ENABLE);
	regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &val);

	/* Enable ADC interrupt for a channel */
	val |= (BIT(channel) << IPROC_ADC_INTR);
	regmap_write(adc_priv->regmap, IPROC_INTERRUPT_MASK, val);

	/*
	 * There seems to be a very rare issue where writing to this register
	 * does not take effect.  To work around the issue we will try multiple
	 * writes.  In total we will spend about 10*10 = 100 us attempting this.
	 * Testing has shown that this may loop a few time, but we have never
	 * hit the full count.
	 */
	regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &val_check);
	while (val_check != val) {
		failed_cnt++;

		if (failed_cnt > IPROC_ADC_INTMASK_RETRY_ATTEMPTS)
			break;

		udelay(10);
		regmap_update_bits(adc_priv->regmap, IPROC_INTERRUPT_MASK,
				IPROC_ADC_INTR_MASK,
				((0x1 << channel) <<
				IPROC_ADC_INTR));

		regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &val_check);
	}

	if (failed_cnt) {
		dev_dbg(&indio_dev->dev,
			"IntMask failed (%d times)", failed_cnt);
		if (failed_cnt > IPROC_ADC_INTMASK_RETRY_ATTEMPTS) {
			dev_err(&indio_dev->dev,
				"IntMask set failed. Read will likely fail.");
			read_len = -EIO;
			goto adc_err;
		};
	}
	regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &val_check);

	if (wait_for_completion_timeout(&adc_priv->completion,
		IPROC_ADC_READ_TIMEOUT) > 0) {

		/* Only the lower 16 bits are relevant */
		*p_adc_data = adc_priv->chan_val & 0xFFFF;
		read_len = sizeof(*p_adc_data);

	} else {
		/*
		 * We never got the interrupt, something went wrong.
		 * Perhaps the interrupt may still be coming, we do not want
		 * that now.  Lets disable the ADC interrupt, and clear the
		 * status to put it back in to normal state.
		 */
		read_len = -ETIMEDOUT;
		goto adc_err;
	}
	mutex_unlock(&adc_priv->mutex);

	return read_len;

adc_err:
	regmap_update_bits(adc_priv->regmap, IPROC_INTERRUPT_MASK,
			   IPROC_ADC_INTR_MASK,
			   ((0x0 << channel) << IPROC_ADC_INTR));

	regmap_update_bits(adc_priv->regmap, IPROC_INTERRUPT_STATUS,
			   IPROC_ADC_INTR_MASK,
			   ((0x0 << channel) << IPROC_ADC_INTR));

	dev_err(&indio_dev->dev, "Timed out waiting for ADC data!\n");
	iproc_adc_reg_dump(indio_dev);
	mutex_unlock(&adc_priv->mutex);

	return read_len;
}

static int iproc_adc_enable(struct iio_dev *indio_dev)
{
	u32 val;
	u32 channel_id;
	struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
	int ret;

	/* Set i_amux = 3b'000, select channel 0 */
	ret = regmap_update_bits(adc_priv->regmap, IPROC_ANALOG_CONTROL,
				IPROC_ADC_CHANNEL_SEL_MASK, 0);
	if (ret) {
		dev_err(&indio_dev->dev,
			"failed to write IPROC_ANALOG_CONTROL %d\n", ret);
		return ret;
	}
	adc_priv->chan_val = -1;

	/*
	 * PWR up LDO, ADC, and Band Gap (0 to enable)
	 * Also enable ADC controller (set high)
	 */
	ret = regmap_read(adc_priv->regmap, IPROC_REGCTL2, &val);
	if (ret) {
		dev_err(&indio_dev->dev,
			"failed to read IPROC_REGCTL2 %d\n", ret);
		return ret;
	}

	val &= ~(IPROC_ADC_PWR_LDO | IPROC_ADC_PWR_ADC | IPROC_ADC_PWR_BG);

	ret = regmap_write(adc_priv->regmap, IPROC_REGCTL2, val);
	if (ret) {
		dev_err(&indio_dev->dev,
			"failed to write IPROC_REGCTL2 %d\n", ret);
		return ret;
	}

	ret = regmap_read(adc_priv->regmap, IPROC_REGCTL2, &val);
	if (ret) {
		dev_err(&indio_dev->dev,
			"failed to read IPROC_REGCTL2 %d\n", ret);
		return ret;
	}

	val |= IPROC_ADC_CONTROLLER_EN;
	ret = regmap_write(adc_priv->regmap, IPROC_REGCTL2, val);
	if (ret) {
		dev_err(&indio_dev->dev,
			"failed to write IPROC_REGCTL2 %d\n", ret);
		return ret;
	}

	for (channel_id = 0; channel_id < indio_dev->num_channels;
		channel_id++) {
		ret = regmap_write(adc_priv->regmap,
				IPROC_ADC_CHANNEL_INTERRUPT_MASK +
				IPROC_ADC_CHANNEL_OFFSET * channel_id, 0);
		if (ret) {
			dev_err(&indio_dev->dev,
			    "failed to write ADC_CHANNEL_INTERRUPT_MASK %d\n",
			    ret);
			return ret;
		}

		ret = regmap_write(adc_priv->regmap,
				IPROC_ADC_CHANNEL_INTERRUPT_STATUS +
				IPROC_ADC_CHANNEL_OFFSET * channel_id, 0);
		if (ret) {
			dev_err(&indio_dev->dev,
			    "failed to write ADC_CHANNEL_INTERRUPT_STATUS %d\n",
			    ret);
			return ret;
		}
	}

	return 0;
}

static void iproc_adc_disable(struct iio_dev *indio_dev)
{
	u32 val;
	int ret;
	struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);

	ret = regmap_read(adc_priv->regmap, IPROC_REGCTL2, &val);
	if (ret) {
		dev_err(&indio_dev->dev,
			"failed to read IPROC_REGCTL2 %d\n", ret);
		return;
	}

	val &= ~IPROC_ADC_CONTROLLER_EN;
	ret = regmap_write(adc_priv->regmap, IPROC_REGCTL2, val);
	if (ret) {
		dev_err(&indio_dev->dev,
			"failed to write IPROC_REGCTL2 %d\n", ret);
		return;
	}
}

static int iproc_adc_read_raw(struct iio_dev *indio_dev,
			  struct iio_chan_spec const *chan,
			  int *val,
			  int *val2,
			  long mask)
{
	u16 adc_data;
	int err;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		err =  iproc_adc_do_read(indio_dev, chan->channel, &adc_data);
		if (err < 0)
			return err;
		*val = adc_data;
		return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
		switch (chan->type) {
		case IIO_VOLTAGE:
			*val = 1800;
			*val2 = 10;
			return IIO_VAL_FRACTIONAL_LOG2;
		default:
			return -EINVAL;
		}
	default:
		return -EINVAL;
	}
}

static const struct iio_info iproc_adc_iio_info = {
	.read_raw = &iproc_adc_read_raw,
};

#define IPROC_ADC_CHANNEL(_index, _id) {                \
	.type = IIO_VOLTAGE,                            \
	.indexed = 1,                                   \
	.channel = _index,                              \
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),   \
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
	.datasheet_name = _id,                          \
}

static const struct iio_chan_spec iproc_adc_iio_channels[] = {
	IPROC_ADC_CHANNEL(0, "adc0"),
	IPROC_ADC_CHANNEL(1, "adc1"),
	IPROC_ADC_CHANNEL(2, "adc2"),
	IPROC_ADC_CHANNEL(3, "adc3"),
	IPROC_ADC_CHANNEL(4, "adc4"),
	IPROC_ADC_CHANNEL(5, "adc5"),
	IPROC_ADC_CHANNEL(6, "adc6"),
	IPROC_ADC_CHANNEL(7, "adc7"),
};

static int iproc_adc_probe(struct platform_device *pdev)
{
	struct iproc_adc_priv *adc_priv;
	struct iio_dev *indio_dev = NULL;
	int ret;

	indio_dev = devm_iio_device_alloc(&pdev->dev,
					sizeof(*adc_priv));
	if (!indio_dev) {
		dev_err(&pdev->dev, "failed to allocate iio device\n");
		return -ENOMEM;
	}

	adc_priv = iio_priv(indio_dev);
	platform_set_drvdata(pdev, indio_dev);

	mutex_init(&adc_priv->mutex);

	init_completion(&adc_priv->completion);

	adc_priv->regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
			   "adc-syscon");
	if (IS_ERR(adc_priv->regmap)) {
		dev_err(&pdev->dev, "failed to get handle for tsc syscon\n");
		ret = PTR_ERR(adc_priv->regmap);
		return ret;
	}

	adc_priv->adc_clk = devm_clk_get(&pdev->dev, "tsc_clk");
	if (IS_ERR(adc_priv->adc_clk)) {
		dev_err(&pdev->dev,
			"failed getting clock tsc_clk\n");
		ret = PTR_ERR(adc_priv->adc_clk);
		return ret;
	}

	adc_priv->irqno = platform_get_irq(pdev, 0);
	if (adc_priv->irqno <= 0) {
		dev_err(&pdev->dev, "platform_get_irq failed\n");
		ret = -ENODEV;
		return ret;
	}

	ret = regmap_update_bits(adc_priv->regmap, IPROC_REGCTL2,
				IPROC_ADC_AUXIN_SCAN_ENA, 0);
	if (ret) {
		dev_err(&pdev->dev, "failed to write IPROC_REGCTL2 %d\n", ret);
		return ret;
	}

	ret = devm_request_threaded_irq(&pdev->dev, adc_priv->irqno,
				iproc_adc_interrupt_handler,
				iproc_adc_interrupt_thread,
				IRQF_SHARED, "iproc-adc", indio_dev);
	if (ret) {
		dev_err(&pdev->dev, "request_irq error %d\n", ret);
		return ret;
	}

	ret = clk_prepare_enable(adc_priv->adc_clk);
	if (ret) {
		dev_err(&pdev->dev,
			"clk_prepare_enable failed %d\n", ret);
		return ret;
	}

	ret = iproc_adc_enable(indio_dev);
	if (ret) {
		dev_err(&pdev->dev, "failed to enable adc %d\n", ret);
		goto err_adc_enable;
	}

	indio_dev->name = "iproc-static-adc";
	indio_dev->dev.parent = &pdev->dev;
	indio_dev->dev.of_node = pdev->dev.of_node;
	indio_dev->info = &iproc_adc_iio_info;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = iproc_adc_iio_channels;
	indio_dev->num_channels = ARRAY_SIZE(iproc_adc_iio_channels);

	ret = iio_device_register(indio_dev);
	if (ret) {
		dev_err(&pdev->dev, "iio_device_register failed:err %d\n", ret);
		goto err_clk;
	}

	return 0;

err_clk:
	iproc_adc_disable(indio_dev);
err_adc_enable:
	clk_disable_unprepare(adc_priv->adc_clk);

	return ret;
}

static int iproc_adc_remove(struct platform_device *pdev)
{
	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
	struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);

	iio_device_unregister(indio_dev);
	iproc_adc_disable(indio_dev);
	clk_disable_unprepare(adc_priv->adc_clk);

	return 0;
}

static const struct of_device_id iproc_adc_of_match[] = {
	{.compatible = "brcm,iproc-static-adc", },
	{ },
};
MODULE_DEVICE_TABLE(of, iproc_adc_of_match);

static struct platform_driver iproc_adc_driver = {
	.probe  = iproc_adc_probe,
	.remove	= iproc_adc_remove,
	.driver	= {
		.name	= "iproc-static-adc",
		.of_match_table = of_match_ptr(iproc_adc_of_match),
	},
};
module_platform_driver(iproc_adc_driver);

MODULE_DESCRIPTION("Broadcom iProc ADC controller driver");
MODULE_AUTHOR("Raveendra Padasalagi <raveendra.padasalagi@broadcom.com>");
MODULE_LICENSE("GPL v2");