summaryrefslogtreecommitdiffstats
path: root/drivers/iio/adc/mxs-lradc-adc.c
blob: 9d2f74c2489a873ae0a5baf3c44423d7214d9806 (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
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Freescale MXS LRADC ADC driver
 *
 * Copyright (c) 2012 DENX Software Engineering, GmbH.
 * Copyright (c) 2017 Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
 *
 * Authors:
 *  Marek Vasut <marex@denx.de>
 *  Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
 */

#include <linux/completion.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/mfd/core.h>
#include <linux/mfd/mxs-lradc.h>
#include <linux/module.h>
#include <linux/of_irq.h>
#include <linux/platform_device.h>
#include <linux/sysfs.h>

#include <linux/iio/buffer.h>
#include <linux/iio/iio.h>
#include <linux/iio/trigger.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/sysfs.h>

/*
 * Make this runtime configurable if necessary. Currently, if the buffered mode
 * is enabled, the LRADC takes LRADC_DELAY_TIMER_LOOP samples of data before
 * triggering IRQ. The sampling happens every (LRADC_DELAY_TIMER_PER / 2000)
 * seconds. The result is that the samples arrive every 500mS.
 */
#define LRADC_DELAY_TIMER_PER	200
#define LRADC_DELAY_TIMER_LOOP	5

#define VREF_MV_BASE 1850

static const char *mx23_lradc_adc_irq_names[] = {
	"mxs-lradc-channel0",
	"mxs-lradc-channel1",
	"mxs-lradc-channel2",
	"mxs-lradc-channel3",
	"mxs-lradc-channel4",
	"mxs-lradc-channel5",
};

static const char *mx28_lradc_adc_irq_names[] = {
	"mxs-lradc-thresh0",
	"mxs-lradc-thresh1",
	"mxs-lradc-channel0",
	"mxs-lradc-channel1",
	"mxs-lradc-channel2",
	"mxs-lradc-channel3",
	"mxs-lradc-channel4",
	"mxs-lradc-channel5",
	"mxs-lradc-button0",
	"mxs-lradc-button1",
};

static const u32 mxs_lradc_adc_vref_mv[][LRADC_MAX_TOTAL_CHANS] = {
	[IMX23_LRADC] = {
		VREF_MV_BASE,		/* CH0 */
		VREF_MV_BASE,		/* CH1 */
		VREF_MV_BASE,		/* CH2 */
		VREF_MV_BASE,		/* CH3 */
		VREF_MV_BASE,		/* CH4 */
		VREF_MV_BASE,		/* CH5 */
		VREF_MV_BASE * 2,	/* CH6 VDDIO */
		VREF_MV_BASE * 4,	/* CH7 VBATT */
		VREF_MV_BASE,		/* CH8 Temp sense 0 */
		VREF_MV_BASE,		/* CH9 Temp sense 1 */
		VREF_MV_BASE,		/* CH10 */
		VREF_MV_BASE,		/* CH11 */
		VREF_MV_BASE,		/* CH12 USB_DP */
		VREF_MV_BASE,		/* CH13 USB_DN */
		VREF_MV_BASE,		/* CH14 VBG */
		VREF_MV_BASE * 4,	/* CH15 VDD5V */
	},
	[IMX28_LRADC] = {
		VREF_MV_BASE,		/* CH0 */
		VREF_MV_BASE,		/* CH1 */
		VREF_MV_BASE,		/* CH2 */
		VREF_MV_BASE,		/* CH3 */
		VREF_MV_BASE,		/* CH4 */
		VREF_MV_BASE,		/* CH5 */
		VREF_MV_BASE,		/* CH6 */
		VREF_MV_BASE * 4,	/* CH7 VBATT */
		VREF_MV_BASE,		/* CH8 Temp sense 0 */
		VREF_MV_BASE,		/* CH9 Temp sense 1 */
		VREF_MV_BASE * 2,	/* CH10 VDDIO */
		VREF_MV_BASE,		/* CH11 VTH */
		VREF_MV_BASE * 2,	/* CH12 VDDA */
		VREF_MV_BASE,		/* CH13 VDDD */
		VREF_MV_BASE,		/* CH14 VBG */
		VREF_MV_BASE * 4,	/* CH15 VDD5V */
	},
};

enum mxs_lradc_divbytwo {
	MXS_LRADC_DIV_DISABLED = 0,
	MXS_LRADC_DIV_ENABLED,
};

struct mxs_lradc_scale {
	unsigned int		integer;
	unsigned int		nano;
};

struct mxs_lradc_adc {
	struct mxs_lradc	*lradc;
	struct device		*dev;

	void __iomem		*base;
	u32			buffer[10];
	struct iio_trigger	*trig;
	struct completion	completion;
	spinlock_t		lock;

	const u32		*vref_mv;
	struct mxs_lradc_scale	scale_avail[LRADC_MAX_TOTAL_CHANS][2];
	unsigned long		is_divided;
};


/* Raw I/O operations */
static int mxs_lradc_adc_read_single(struct iio_dev *iio_dev, int chan,
				     int *val)
{
	struct mxs_lradc_adc *adc = iio_priv(iio_dev);
	struct mxs_lradc *lradc = adc->lradc;
	int ret;

	/*
	 * See if there is no buffered operation in progress. If there is simply
	 * bail out. This can be improved to support both buffered and raw IO at
	 * the same time, yet the code becomes horribly complicated. Therefore I
	 * applied KISS principle here.
	 */
	ret = iio_device_claim_direct_mode(iio_dev);
	if (ret)
		return ret;

	reinit_completion(&adc->completion);

	/*
	 * No buffered operation in progress, map the channel and trigger it.
	 * Virtual channel 0 is always used here as the others are always not
	 * used if doing raw sampling.
	 */
	if (lradc->soc == IMX28_LRADC)
		writel(LRADC_CTRL1_LRADC_IRQ_EN(0),
		       adc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
	writel(0x1, adc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);

	/* Enable / disable the divider per requirement */
	if (test_bit(chan, &adc->is_divided))
		writel(1 << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET,
		       adc->base + LRADC_CTRL2 + STMP_OFFSET_REG_SET);
	else
		writel(1 << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET,
		       adc->base + LRADC_CTRL2 + STMP_OFFSET_REG_CLR);

	/* Clean the slot's previous content, then set new one. */
	writel(LRADC_CTRL4_LRADCSELECT_MASK(0),
	       adc->base + LRADC_CTRL4 + STMP_OFFSET_REG_CLR);
	writel(chan, adc->base + LRADC_CTRL4 + STMP_OFFSET_REG_SET);

	writel(0, adc->base + LRADC_CH(0));

	/* Enable the IRQ and start sampling the channel. */
	writel(LRADC_CTRL1_LRADC_IRQ_EN(0),
	       adc->base + LRADC_CTRL1 + STMP_OFFSET_REG_SET);
	writel(BIT(0), adc->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET);

	/* Wait for completion on the channel, 1 second max. */
	ret = wait_for_completion_killable_timeout(&adc->completion, HZ);
	if (!ret)
		ret = -ETIMEDOUT;
	if (ret < 0)
		goto err;

	/* Read the data. */
	*val = readl(adc->base + LRADC_CH(0)) & LRADC_CH_VALUE_MASK;
	ret = IIO_VAL_INT;

err:
	writel(LRADC_CTRL1_LRADC_IRQ_EN(0),
	       adc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);

	iio_device_release_direct_mode(iio_dev);

	return ret;
}

static int mxs_lradc_adc_read_temp(struct iio_dev *iio_dev, int *val)
{
	int ret, min, max;

	ret = mxs_lradc_adc_read_single(iio_dev, 8, &min);
	if (ret != IIO_VAL_INT)
		return ret;

	ret = mxs_lradc_adc_read_single(iio_dev, 9, &max);
	if (ret != IIO_VAL_INT)
		return ret;

	*val = max - min;

	return IIO_VAL_INT;
}

static int mxs_lradc_adc_read_raw(struct iio_dev *iio_dev,
			      const struct iio_chan_spec *chan,
			      int *val, int *val2, long m)
{
	struct mxs_lradc_adc *adc = iio_priv(iio_dev);

	switch (m) {
	case IIO_CHAN_INFO_RAW:
		if (chan->type == IIO_TEMP)
			return mxs_lradc_adc_read_temp(iio_dev, val);

		return mxs_lradc_adc_read_single(iio_dev, chan->channel, val);

	case IIO_CHAN_INFO_SCALE:
		if (chan->type == IIO_TEMP) {
			/*
			 * From the datasheet, we have to multiply by 1.012 and
			 * divide by 4
			 */
			*val = 0;
			*val2 = 253000;
			return IIO_VAL_INT_PLUS_MICRO;
		}

		*val = adc->vref_mv[chan->channel];
		*val2 = chan->scan_type.realbits -
			test_bit(chan->channel, &adc->is_divided);
		return IIO_VAL_FRACTIONAL_LOG2;

	case IIO_CHAN_INFO_OFFSET:
		if (chan->type == IIO_TEMP) {
			/*
			 * The calculated value from the ADC is in Kelvin, we
			 * want Celsius for hwmon so the offset is -273.15
			 * The offset is applied before scaling so it is
			 * actually -213.15 * 4 / 1.012 = -1079.644268
			 */
			*val = -1079;
			*val2 = 644268;

			return IIO_VAL_INT_PLUS_MICRO;
		}

		return -EINVAL;

	default:
		break;
	}

	return -EINVAL;
}

static int mxs_lradc_adc_write_raw(struct iio_dev *iio_dev,
				   const struct iio_chan_spec *chan,
				   int val, int val2, long m)
{
	struct mxs_lradc_adc *adc = iio_priv(iio_dev);
	struct mxs_lradc_scale *scale_avail =
			adc->scale_avail[chan->channel];
	int ret;

	ret = iio_device_claim_direct_mode(iio_dev);
	if (ret)
		return ret;

	switch (m) {
	case IIO_CHAN_INFO_SCALE:
		ret = -EINVAL;
		if (val == scale_avail[MXS_LRADC_DIV_DISABLED].integer &&
		    val2 == scale_avail[MXS_LRADC_DIV_DISABLED].nano) {
			/* divider by two disabled */
			clear_bit(chan->channel, &adc->is_divided);
			ret = 0;
		} else if (val == scale_avail[MXS_LRADC_DIV_ENABLED].integer &&
			   val2 == scale_avail[MXS_LRADC_DIV_ENABLED].nano) {
			/* divider by two enabled */
			set_bit(chan->channel, &adc->is_divided);
			ret = 0;
		}

		break;
	default:
		ret = -EINVAL;
		break;
	}

	iio_device_release_direct_mode(iio_dev);

	return ret;
}

static int mxs_lradc_adc_write_raw_get_fmt(struct iio_dev *iio_dev,
					   const struct iio_chan_spec *chan,
					   long m)
{
	return IIO_VAL_INT_PLUS_NANO;
}

static ssize_t mxs_lradc_adc_show_scale_avail(struct device *dev,
						 struct device_attribute *attr,
						 char *buf)
{
	struct iio_dev *iio = dev_to_iio_dev(dev);
	struct mxs_lradc_adc *adc = iio_priv(iio);
	struct iio_dev_attr *iio_attr = to_iio_dev_attr(attr);
	int i, ch, len = 0;

	ch = iio_attr->address;
	for (i = 0; i < ARRAY_SIZE(adc->scale_avail[ch]); i++)
		len += sprintf(buf + len, "%u.%09u ",
			       adc->scale_avail[ch][i].integer,
			       adc->scale_avail[ch][i].nano);

	len += sprintf(buf + len, "\n");

	return len;
}

#define SHOW_SCALE_AVAILABLE_ATTR(ch)\
	IIO_DEVICE_ATTR(in_voltage##ch##_scale_available, 0444,\
			mxs_lradc_adc_show_scale_avail, NULL, ch)

static SHOW_SCALE_AVAILABLE_ATTR(0);
static SHOW_SCALE_AVAILABLE_ATTR(1);
static SHOW_SCALE_AVAILABLE_ATTR(2);
static SHOW_SCALE_AVAILABLE_ATTR(3);
static SHOW_SCALE_AVAILABLE_ATTR(4);
static SHOW_SCALE_AVAILABLE_ATTR(5);
static SHOW_SCALE_AVAILABLE_ATTR(6);
static SHOW_SCALE_AVAILABLE_ATTR(7);
static SHOW_SCALE_AVAILABLE_ATTR(10);
static SHOW_SCALE_AVAILABLE_ATTR(11);
static SHOW_SCALE_AVAILABLE_ATTR(12);
static SHOW_SCALE_AVAILABLE_ATTR(13);
static SHOW_SCALE_AVAILABLE_ATTR(14);
static SHOW_SCALE_AVAILABLE_ATTR(15);

static struct attribute *mxs_lradc_adc_attributes[] = {
	&iio_dev_attr_in_voltage0_scale_available.dev_attr.attr,
	&iio_dev_attr_in_voltage1_scale_available.dev_attr.attr,
	&iio_dev_attr_in_voltage2_scale_available.dev_attr.attr,
	&iio_dev_attr_in_voltage3_scale_available.dev_attr.attr,
	&iio_dev_attr_in_voltage4_scale_available.dev_attr.attr,
	&iio_dev_attr_in_voltage5_scale_available.dev_attr.attr,
	&iio_dev_attr_in_voltage6_scale_available.dev_attr.attr,
	&iio_dev_attr_in_voltage7_scale_available.dev_attr.attr,
	&iio_dev_attr_in_voltage10_scale_available.dev_attr.attr,
	&iio_dev_attr_in_voltage11_scale_available.dev_attr.attr,
	&iio_dev_attr_in_voltage12_scale_available.dev_attr.attr,
	&iio_dev_attr_in_voltage13_scale_available.dev_attr.attr,
	&iio_dev_attr_in_voltage14_scale_available.dev_attr.attr,
	&iio_dev_attr_in_voltage15_scale_available.dev_attr.attr,
	NULL
};

static const struct attribute_group mxs_lradc_adc_attribute_group = {
	.attrs = mxs_lradc_adc_attributes,
};

static const struct iio_info mxs_lradc_adc_iio_info = {
	.read_raw		= mxs_lradc_adc_read_raw,
	.write_raw		= mxs_lradc_adc_write_raw,
	.write_raw_get_fmt	= mxs_lradc_adc_write_raw_get_fmt,
	.attrs			= &mxs_lradc_adc_attribute_group,
};

/* IRQ Handling */
static irqreturn_t mxs_lradc_adc_handle_irq(int irq, void *data)
{
	struct iio_dev *iio = data;
	struct mxs_lradc_adc *adc = iio_priv(iio);
	struct mxs_lradc *lradc = adc->lradc;
	unsigned long reg = readl(adc->base + LRADC_CTRL1);
	unsigned long flags;

	if (!(reg & mxs_lradc_irq_mask(lradc)))
		return IRQ_NONE;

	if (iio_buffer_enabled(iio)) {
		if (reg & lradc->buffer_vchans) {
			spin_lock_irqsave(&adc->lock, flags);
			iio_trigger_poll(iio->trig);
			spin_unlock_irqrestore(&adc->lock, flags);
		}
	} else if (reg & LRADC_CTRL1_LRADC_IRQ(0)) {
		complete(&adc->completion);
	}

	writel(reg & mxs_lradc_irq_mask(lradc),
	       adc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);

	return IRQ_HANDLED;
}


/* Trigger handling */
static irqreturn_t mxs_lradc_adc_trigger_handler(int irq, void *p)
{
	struct iio_poll_func *pf = p;
	struct iio_dev *iio = pf->indio_dev;
	struct mxs_lradc_adc *adc = iio_priv(iio);
	const u32 chan_value = LRADC_CH_ACCUMULATE |
		((LRADC_DELAY_TIMER_LOOP - 1) << LRADC_CH_NUM_SAMPLES_OFFSET);
	unsigned int i, j = 0;

	for_each_set_bit(i, iio->active_scan_mask, LRADC_MAX_TOTAL_CHANS) {
		adc->buffer[j] = readl(adc->base + LRADC_CH(j));
		writel(chan_value, adc->base + LRADC_CH(j));
		adc->buffer[j] &= LRADC_CH_VALUE_MASK;
		adc->buffer[j] /= LRADC_DELAY_TIMER_LOOP;
		j++;
	}

	iio_push_to_buffers_with_timestamp(iio, adc->buffer, pf->timestamp);

	iio_trigger_notify_done(iio->trig);

	return IRQ_HANDLED;
}

static int mxs_lradc_adc_configure_trigger(struct iio_trigger *trig, bool state)
{
	struct iio_dev *iio = iio_trigger_get_drvdata(trig);
	struct mxs_lradc_adc *adc = iio_priv(iio);
	const u32 st = state ? STMP_OFFSET_REG_SET : STMP_OFFSET_REG_CLR;

	writel(LRADC_DELAY_KICK, adc->base + (LRADC_DELAY(0) + st));

	return 0;
}

static const struct iio_trigger_ops mxs_lradc_adc_trigger_ops = {
	.set_trigger_state = &mxs_lradc_adc_configure_trigger,
};

static int mxs_lradc_adc_trigger_init(struct iio_dev *iio)
{
	int ret;
	struct iio_trigger *trig;
	struct mxs_lradc_adc *adc = iio_priv(iio);

	trig = devm_iio_trigger_alloc(&iio->dev, "%s-dev%i", iio->name,
				      iio->id);
	if (!trig)
		return -ENOMEM;

	trig->dev.parent = adc->dev;
	iio_trigger_set_drvdata(trig, iio);
	trig->ops = &mxs_lradc_adc_trigger_ops;

	ret = iio_trigger_register(trig);
	if (ret)
		return ret;

	adc->trig = trig;

	return 0;
}

static void mxs_lradc_adc_trigger_remove(struct iio_dev *iio)
{
	struct mxs_lradc_adc *adc = iio_priv(iio);

	iio_trigger_unregister(adc->trig);
}

static int mxs_lradc_adc_buffer_preenable(struct iio_dev *iio)
{
	struct mxs_lradc_adc *adc = iio_priv(iio);
	struct mxs_lradc *lradc = adc->lradc;
	int chan, ofs = 0;
	unsigned long enable = 0;
	u32 ctrl4_set = 0;
	u32 ctrl4_clr = 0;
	u32 ctrl1_irq = 0;
	const u32 chan_value = LRADC_CH_ACCUMULATE |
		((LRADC_DELAY_TIMER_LOOP - 1) << LRADC_CH_NUM_SAMPLES_OFFSET);

	if (lradc->soc == IMX28_LRADC)
		writel(lradc->buffer_vchans << LRADC_CTRL1_LRADC_IRQ_EN_OFFSET,
		       adc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
	writel(lradc->buffer_vchans,
	       adc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);

	for_each_set_bit(chan, iio->active_scan_mask, LRADC_MAX_TOTAL_CHANS) {
		ctrl4_set |= chan << LRADC_CTRL4_LRADCSELECT_OFFSET(ofs);
		ctrl4_clr |= LRADC_CTRL4_LRADCSELECT_MASK(ofs);
		ctrl1_irq |= LRADC_CTRL1_LRADC_IRQ_EN(ofs);
		writel(chan_value, adc->base + LRADC_CH(ofs));
		bitmap_set(&enable, ofs, 1);
		ofs++;
	}

	writel(LRADC_DELAY_TRIGGER_LRADCS_MASK | LRADC_DELAY_KICK,
	       adc->base + LRADC_DELAY(0) + STMP_OFFSET_REG_CLR);
	writel(ctrl4_clr, adc->base + LRADC_CTRL4 + STMP_OFFSET_REG_CLR);
	writel(ctrl4_set, adc->base + LRADC_CTRL4 + STMP_OFFSET_REG_SET);
	writel(ctrl1_irq, adc->base + LRADC_CTRL1 + STMP_OFFSET_REG_SET);
	writel(enable << LRADC_DELAY_TRIGGER_LRADCS_OFFSET,
	       adc->base + LRADC_DELAY(0) + STMP_OFFSET_REG_SET);

	return 0;
}

static int mxs_lradc_adc_buffer_postdisable(struct iio_dev *iio)
{
	struct mxs_lradc_adc *adc = iio_priv(iio);
	struct mxs_lradc *lradc = adc->lradc;

	writel(LRADC_DELAY_TRIGGER_LRADCS_MASK | LRADC_DELAY_KICK,
	       adc->base + LRADC_DELAY(0) + STMP_OFFSET_REG_CLR);

	writel(lradc->buffer_vchans,
	       adc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);
	if (lradc->soc == IMX28_LRADC)
		writel(lradc->buffer_vchans << LRADC_CTRL1_LRADC_IRQ_EN_OFFSET,
		       adc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);

	return 0;
}

static bool mxs_lradc_adc_validate_scan_mask(struct iio_dev *iio,
					     const unsigned long *mask)
{
	struct mxs_lradc_adc *adc = iio_priv(iio);
	struct mxs_lradc *lradc = adc->lradc;
	const int map_chans = bitmap_weight(mask, LRADC_MAX_TOTAL_CHANS);
	int rsvd_chans = 0;
	unsigned long rsvd_mask = 0;

	if (lradc->use_touchbutton)
		rsvd_mask |= CHAN_MASK_TOUCHBUTTON;
	if (lradc->touchscreen_wire == MXS_LRADC_TOUCHSCREEN_4WIRE)
		rsvd_mask |= CHAN_MASK_TOUCHSCREEN_4WIRE;
	if (lradc->touchscreen_wire == MXS_LRADC_TOUCHSCREEN_5WIRE)
		rsvd_mask |= CHAN_MASK_TOUCHSCREEN_5WIRE;

	if (lradc->use_touchbutton)
		rsvd_chans++;
	if (lradc->touchscreen_wire)
		rsvd_chans += 2;

	/* Test for attempts to map channels with special mode of operation. */
	if (bitmap_intersects(mask, &rsvd_mask, LRADC_MAX_TOTAL_CHANS))
		return false;

	/* Test for attempts to map more channels then available slots. */
	if (map_chans + rsvd_chans > LRADC_MAX_MAPPED_CHANS)
		return false;

	return true;
}

static const struct iio_buffer_setup_ops mxs_lradc_adc_buffer_ops = {
	.preenable = &mxs_lradc_adc_buffer_preenable,
	.postenable = &iio_triggered_buffer_postenable,
	.predisable = &iio_triggered_buffer_predisable,
	.postdisable = &mxs_lradc_adc_buffer_postdisable,
	.validate_scan_mask = &mxs_lradc_adc_validate_scan_mask,
};

/* Driver initialization */
#define MXS_ADC_CHAN(idx, chan_type, name) {			\
	.type = (chan_type),					\
	.indexed = 1,						\
	.scan_index = (idx),					\
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
			      BIT(IIO_CHAN_INFO_SCALE),		\
	.channel = (idx),					\
	.address = (idx),					\
	.scan_type = {						\
		.sign = 'u',					\
		.realbits = LRADC_RESOLUTION,			\
		.storagebits = 32,				\
	},							\
	.datasheet_name = (name),				\
}

static const struct iio_chan_spec mx23_lradc_chan_spec[] = {
	MXS_ADC_CHAN(0, IIO_VOLTAGE, "LRADC0"),
	MXS_ADC_CHAN(1, IIO_VOLTAGE, "LRADC1"),
	MXS_ADC_CHAN(2, IIO_VOLTAGE, "LRADC2"),
	MXS_ADC_CHAN(3, IIO_VOLTAGE, "LRADC3"),
	MXS_ADC_CHAN(4, IIO_VOLTAGE, "LRADC4"),
	MXS_ADC_CHAN(5, IIO_VOLTAGE, "LRADC5"),
	MXS_ADC_CHAN(6, IIO_VOLTAGE, "VDDIO"),
	MXS_ADC_CHAN(7, IIO_VOLTAGE, "VBATT"),
	/* Combined Temperature sensors */
	{
		.type = IIO_TEMP,
		.indexed = 1,
		.scan_index = 8,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
				      BIT(IIO_CHAN_INFO_OFFSET) |
				      BIT(IIO_CHAN_INFO_SCALE),
		.channel = 8,
		.scan_type = {.sign = 'u', .realbits = 18, .storagebits = 32,},
		.datasheet_name = "TEMP_DIE",
	},
	/* Hidden channel to keep indexes */
	{
		.type = IIO_TEMP,
		.indexed = 1,
		.scan_index = -1,
		.channel = 9,
	},
	MXS_ADC_CHAN(10, IIO_VOLTAGE, NULL),
	MXS_ADC_CHAN(11, IIO_VOLTAGE, NULL),
	MXS_ADC_CHAN(12, IIO_VOLTAGE, "USB_DP"),
	MXS_ADC_CHAN(13, IIO_VOLTAGE, "USB_DN"),
	MXS_ADC_CHAN(14, IIO_VOLTAGE, "VBG"),
	MXS_ADC_CHAN(15, IIO_VOLTAGE, "VDD5V"),
};

static const struct iio_chan_spec mx28_lradc_chan_spec[] = {
	MXS_ADC_CHAN(0, IIO_VOLTAGE, "LRADC0"),
	MXS_ADC_CHAN(1, IIO_VOLTAGE, "LRADC1"),
	MXS_ADC_CHAN(2, IIO_VOLTAGE, "LRADC2"),
	MXS_ADC_CHAN(3, IIO_VOLTAGE, "LRADC3"),
	MXS_ADC_CHAN(4, IIO_VOLTAGE, "LRADC4"),
	MXS_ADC_CHAN(5, IIO_VOLTAGE, "LRADC5"),
	MXS_ADC_CHAN(6, IIO_VOLTAGE, "LRADC6"),
	MXS_ADC_CHAN(7, IIO_VOLTAGE, "VBATT"),
	/* Combined Temperature sensors */
	{
		.type = IIO_TEMP,
		.indexed = 1,
		.scan_index = 8,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
				      BIT(IIO_CHAN_INFO_OFFSET) |
				      BIT(IIO_CHAN_INFO_SCALE),
		.channel = 8,
		.scan_type = {.sign = 'u', .realbits = 18, .storagebits = 32,},
		.datasheet_name = "TEMP_DIE",
	},
	/* Hidden channel to keep indexes */
	{
		.type = IIO_TEMP,
		.indexed = 1,
		.scan_index = -1,
		.channel = 9,
	},
	MXS_ADC_CHAN(10, IIO_VOLTAGE, "VDDIO"),
	MXS_ADC_CHAN(11, IIO_VOLTAGE, "VTH"),
	MXS_ADC_CHAN(12, IIO_VOLTAGE, "VDDA"),
	MXS_ADC_CHAN(13, IIO_VOLTAGE, "VDDD"),
	MXS_ADC_CHAN(14, IIO_VOLTAGE, "VBG"),
	MXS_ADC_CHAN(15, IIO_VOLTAGE, "VDD5V"),
};

static void mxs_lradc_adc_hw_init(struct mxs_lradc_adc *adc)
{
	/* The ADC always uses DELAY CHANNEL 0. */
	const u32 adc_cfg =
		(1 << (LRADC_DELAY_TRIGGER_DELAYS_OFFSET + 0)) |
		(LRADC_DELAY_TIMER_PER << LRADC_DELAY_DELAY_OFFSET);

	/* Configure DELAY CHANNEL 0 for generic ADC sampling. */
	writel(adc_cfg, adc->base + LRADC_DELAY(0));

	/*
	 * Start internal temperature sensing by clearing bit
	 * HW_LRADC_CTRL2_TEMPSENSE_PWD. This bit can be left cleared
	 * after power up.
	 */
	writel(0, adc->base + LRADC_CTRL2);
}

static void mxs_lradc_adc_hw_stop(struct mxs_lradc_adc *adc)
{
	writel(0, adc->base + LRADC_DELAY(0));
}

static int mxs_lradc_adc_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct mxs_lradc *lradc = dev_get_drvdata(dev->parent);
	struct mxs_lradc_adc *adc;
	struct iio_dev *iio;
	struct resource *iores;
	int ret, irq, virq, i, s, n;
	u64 scale_uv;
	const char **irq_name;

	/* Allocate the IIO device. */
	iio = devm_iio_device_alloc(dev, sizeof(*adc));
	if (!iio) {
		dev_err(dev, "Failed to allocate IIO device\n");
		return -ENOMEM;
	}

	adc = iio_priv(iio);
	adc->lradc = lradc;
	adc->dev = dev;

	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!iores)
		return -EINVAL;

	adc->base = devm_ioremap(dev, iores->start, resource_size(iores));
	if (!adc->base)
		return -ENOMEM;

	init_completion(&adc->completion);
	spin_lock_init(&adc->lock);

	platform_set_drvdata(pdev, iio);

	iio->name = pdev->name;
	iio->dev.parent = dev;
	iio->dev.of_node = dev->parent->of_node;
	iio->info = &mxs_lradc_adc_iio_info;
	iio->modes = INDIO_DIRECT_MODE;
	iio->masklength = LRADC_MAX_TOTAL_CHANS;

	if (lradc->soc == IMX23_LRADC) {
		iio->channels = mx23_lradc_chan_spec;
		iio->num_channels = ARRAY_SIZE(mx23_lradc_chan_spec);
		irq_name = mx23_lradc_adc_irq_names;
		n = ARRAY_SIZE(mx23_lradc_adc_irq_names);
	} else {
		iio->channels = mx28_lradc_chan_spec;
		iio->num_channels = ARRAY_SIZE(mx28_lradc_chan_spec);
		irq_name = mx28_lradc_adc_irq_names;
		n = ARRAY_SIZE(mx28_lradc_adc_irq_names);
	}

	ret = stmp_reset_block(adc->base);
	if (ret)
		return ret;

	for (i = 0; i < n; i++) {
		irq = platform_get_irq_byname(pdev, irq_name[i]);
		if (irq < 0)
			return irq;

		virq = irq_of_parse_and_map(dev->parent->of_node, irq);

		ret = devm_request_irq(dev, virq, mxs_lradc_adc_handle_irq,
				       0, irq_name[i], iio);
		if (ret)
			return ret;
	}

	ret = mxs_lradc_adc_trigger_init(iio);
	if (ret)
		goto err_trig;

	ret = iio_triggered_buffer_setup(iio, &iio_pollfunc_store_time,
					 &mxs_lradc_adc_trigger_handler,
					 &mxs_lradc_adc_buffer_ops);
	if (ret)
		return ret;

	adc->vref_mv = mxs_lradc_adc_vref_mv[lradc->soc];

	/* Populate available ADC input ranges */
	for (i = 0; i < LRADC_MAX_TOTAL_CHANS; i++) {
		for (s = 0; s < ARRAY_SIZE(adc->scale_avail[i]); s++) {
			/*
			 * [s=0] = optional divider by two disabled (default)
			 * [s=1] = optional divider by two enabled
			 *
			 * The scale is calculated by doing:
			 *   Vref >> (realbits - s)
			 * which multiplies by two on the second component
			 * of the array.
			 */
			scale_uv = ((u64)adc->vref_mv[i] * 100000000) >>
				   (LRADC_RESOLUTION - s);
			adc->scale_avail[i][s].nano =
					do_div(scale_uv, 100000000) * 10;
			adc->scale_avail[i][s].integer = scale_uv;
		}
	}

	/* Configure the hardware. */
	mxs_lradc_adc_hw_init(adc);

	/* Register IIO device. */
	ret = iio_device_register(iio);
	if (ret) {
		dev_err(dev, "Failed to register IIO device\n");
		goto err_dev;
	}

	return 0;

err_dev:
	mxs_lradc_adc_hw_stop(adc);
	mxs_lradc_adc_trigger_remove(iio);
err_trig:
	iio_triggered_buffer_cleanup(iio);
	return ret;
}

static int mxs_lradc_adc_remove(struct platform_device *pdev)
{
	struct iio_dev *iio = platform_get_drvdata(pdev);
	struct mxs_lradc_adc *adc = iio_priv(iio);

	iio_device_unregister(iio);
	mxs_lradc_adc_hw_stop(adc);
	mxs_lradc_adc_trigger_remove(iio);
	iio_triggered_buffer_cleanup(iio);

	return 0;
}

static struct platform_driver mxs_lradc_adc_driver = {
	.driver = {
		.name	= "mxs-lradc-adc",
	},
	.probe	= mxs_lradc_adc_probe,
	.remove = mxs_lradc_adc_remove,
};
module_platform_driver(mxs_lradc_adc_driver);

MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
MODULE_DESCRIPTION("Freescale MXS LRADC driver general purpose ADC driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:mxs-lradc-adc");