summaryrefslogtreecommitdiff
path: root/drivers/iio/adc/rcar-gyroadc.c
blob: 27a3181646191aa1171ffec7923a823a6155bf33 (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
/*
 * Renesas R-Car GyroADC driver
 *
 * Copyright 2016 Marek Vasut <marek.vasut@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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 for more details.
 */

#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/regulator/consumer.h>
#include <linux/of_platform.h>
#include <linux/err.h>
#include <linux/pm_runtime.h>

#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/trigger.h>

#define DRIVER_NAME				"rcar-gyroadc"

/* GyroADC registers. */
#define RCAR_GYROADC_MODE_SELECT		0x00
#define RCAR_GYROADC_MODE_SELECT_1_MB88101A	0x0
#define RCAR_GYROADC_MODE_SELECT_2_ADCS7476	0x1
#define RCAR_GYROADC_MODE_SELECT_3_MAX1162	0x3

#define RCAR_GYROADC_START_STOP			0x04
#define RCAR_GYROADC_START_STOP_START		BIT(0)

#define RCAR_GYROADC_CLOCK_LENGTH		0x08
#define RCAR_GYROADC_1_25MS_LENGTH		0x0c

#define RCAR_GYROADC_REALTIME_DATA(ch)		(0x10 + ((ch) * 4))
#define RCAR_GYROADC_100MS_ADDED_DATA(ch)	(0x30 + ((ch) * 4))
#define RCAR_GYROADC_10MS_AVG_DATA(ch)		(0x50 + ((ch) * 4))

#define RCAR_GYROADC_FIFO_STATUS		0x70
#define RCAR_GYROADC_FIFO_STATUS_EMPTY(ch)	BIT(0 + (4 * (ch)))
#define RCAR_GYROADC_FIFO_STATUS_FULL(ch)	BIT(1 + (4 * (ch)))
#define RCAR_GYROADC_FIFO_STATUS_ERROR(ch)	BIT(2 + (4 * (ch)))

#define RCAR_GYROADC_INTR			0x74
#define RCAR_GYROADC_INTR_INT			BIT(0)

#define RCAR_GYROADC_INTENR			0x78
#define RCAR_GYROADC_INTENR_INTEN		BIT(0)

#define RCAR_GYROADC_SAMPLE_RATE		800	/* Hz */

#define RCAR_GYROADC_RUNTIME_PM_DELAY_MS	2000

enum rcar_gyroadc_model {
	RCAR_GYROADC_MODEL_DEFAULT,
	RCAR_GYROADC_MODEL_R8A7792,
};

struct rcar_gyroadc {
	struct device			*dev;
	void __iomem			*regs;
	struct clk			*clk;
	struct regulator		*vref[8];
	unsigned int			num_channels;
	enum rcar_gyroadc_model		model;
	unsigned int			mode;
	unsigned int			sample_width;
};

static void rcar_gyroadc_hw_init(struct rcar_gyroadc *priv)
{
	const unsigned long clk_mhz = clk_get_rate(priv->clk) / 1000000;
	const unsigned long clk_mul =
		(priv->mode == RCAR_GYROADC_MODE_SELECT_1_MB88101A) ? 10 : 5;
	unsigned long clk_len = clk_mhz * clk_mul;

	/*
	 * According to the R-Car Gen2 datasheet Rev. 1.01, Sept 08 2014,
	 * page 77-7, clock length must be even number. If it's odd number,
	 * add one.
	 */
	if (clk_len & 1)
		clk_len++;

	/* Stop the GyroADC. */
	writel(0, priv->regs + RCAR_GYROADC_START_STOP);

	/* Disable IRQ on V2H. */
	if (priv->model == RCAR_GYROADC_MODEL_R8A7792)
		writel(0, priv->regs + RCAR_GYROADC_INTENR);

	/* Set mode and timing. */
	writel(priv->mode, priv->regs + RCAR_GYROADC_MODE_SELECT);
	writel(clk_len, priv->regs + RCAR_GYROADC_CLOCK_LENGTH);
	writel(clk_mhz * 1250, priv->regs + RCAR_GYROADC_1_25MS_LENGTH);
}

static void rcar_gyroadc_hw_start(struct rcar_gyroadc *priv)
{
	/* Start sampling. */
	writel(RCAR_GYROADC_START_STOP_START,
	       priv->regs + RCAR_GYROADC_START_STOP);

	/*
	 * Wait for the first conversion to complete. This is longer than
	 * the 1.25 mS in the datasheet because 1.25 mS is not enough for
	 * the hardware to deliver the first sample and the hardware does
	 * then return zeroes instead of valid data.
	 */
	mdelay(3);
}

static void rcar_gyroadc_hw_stop(struct rcar_gyroadc *priv)
{
	/* Stop the GyroADC. */
	writel(0, priv->regs + RCAR_GYROADC_START_STOP);
}

#define RCAR_GYROADC_CHAN(_idx) {				\
	.type			= IIO_VOLTAGE,			\
	.indexed		= 1,				\
	.channel		= (_idx),			\
	.info_mask_separate	= BIT(IIO_CHAN_INFO_RAW) |	\
				  BIT(IIO_CHAN_INFO_SCALE),	\
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
}

static const struct iio_chan_spec rcar_gyroadc_iio_channels_1[] = {
	RCAR_GYROADC_CHAN(0),
	RCAR_GYROADC_CHAN(1),
	RCAR_GYROADC_CHAN(2),
	RCAR_GYROADC_CHAN(3),
};

static const struct iio_chan_spec rcar_gyroadc_iio_channels_2[] = {
	RCAR_GYROADC_CHAN(0),
	RCAR_GYROADC_CHAN(1),
	RCAR_GYROADC_CHAN(2),
	RCAR_GYROADC_CHAN(3),
	RCAR_GYROADC_CHAN(4),
	RCAR_GYROADC_CHAN(5),
	RCAR_GYROADC_CHAN(6),
	RCAR_GYROADC_CHAN(7),
};

static const struct iio_chan_spec rcar_gyroadc_iio_channels_3[] = {
	RCAR_GYROADC_CHAN(0),
	RCAR_GYROADC_CHAN(1),
	RCAR_GYROADC_CHAN(2),
	RCAR_GYROADC_CHAN(3),
	RCAR_GYROADC_CHAN(4),
	RCAR_GYROADC_CHAN(5),
	RCAR_GYROADC_CHAN(6),
	RCAR_GYROADC_CHAN(7),
};

static int rcar_gyroadc_set_power(struct rcar_gyroadc *priv, bool on)
{
	struct device *dev = priv->dev;
	int ret;

	if (on) {
		ret = pm_runtime_get_sync(dev);
		if (ret < 0)
			pm_runtime_put_noidle(dev);
	} else {
		pm_runtime_mark_last_busy(dev);
		ret = pm_runtime_put_autosuspend(dev);
	}

	return ret;
}

static int rcar_gyroadc_read_raw(struct iio_dev *indio_dev,
				 struct iio_chan_spec const *chan,
				 int *val, int *val2, long mask)
{
	struct rcar_gyroadc *priv = iio_priv(indio_dev);
	struct regulator *consumer;
	unsigned int datareg = RCAR_GYROADC_REALTIME_DATA(chan->channel);
	unsigned int vref;
	int ret;

	/*
	 * MB88101 is special in that it has only single regulator for
	 * all four channels.
	 */
	if (priv->mode == RCAR_GYROADC_MODE_SELECT_1_MB88101A)
		consumer = priv->vref[0];
	else
		consumer = priv->vref[chan->channel];

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		if (chan->type != IIO_VOLTAGE)
			return -EINVAL;

		/* Channel not connected. */
		if (!consumer)
			return -EINVAL;

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

		ret = rcar_gyroadc_set_power(priv, true);
		if (ret < 0) {
			iio_device_release_direct_mode(indio_dev);
			return ret;
		}

		*val = readl(priv->regs + datareg);
		*val &= BIT(priv->sample_width) - 1;

		ret = rcar_gyroadc_set_power(priv, false);
		iio_device_release_direct_mode(indio_dev);
		if (ret < 0)
			return ret;

		return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
		/* Channel not connected. */
		if (!consumer)
			return -EINVAL;

		vref = regulator_get_voltage(consumer);
		*val = vref / 1000;
		*val2 = 1 << priv->sample_width;

		return IIO_VAL_FRACTIONAL;
	case IIO_CHAN_INFO_SAMP_FREQ:
		*val = RCAR_GYROADC_SAMPLE_RATE;

		return IIO_VAL_INT;
	default:
		return -EINVAL;
	}
}

static int rcar_gyroadc_reg_access(struct iio_dev *indio_dev,
				   unsigned int reg, unsigned int writeval,
				   unsigned int *readval)
{
	struct rcar_gyroadc *priv = iio_priv(indio_dev);
	unsigned int maxreg = RCAR_GYROADC_FIFO_STATUS;

	if (readval == NULL)
		return -EINVAL;

	if (reg % 4)
		return -EINVAL;

	/* Handle the V2H case with extra interrupt block. */
	if (priv->model == RCAR_GYROADC_MODEL_R8A7792)
		maxreg = RCAR_GYROADC_INTENR;

	if (reg > maxreg)
		return -EINVAL;

	*readval = readl(priv->regs + reg);

	return 0;
}

static const struct iio_info rcar_gyroadc_iio_info = {
	.driver_module		= THIS_MODULE,
	.read_raw		= rcar_gyroadc_read_raw,
	.debugfs_reg_access	= rcar_gyroadc_reg_access,
};

static const struct of_device_id rcar_gyroadc_match[] = {
	{
		/* R-Car compatible GyroADC */
		.compatible	= "renesas,rcar-gyroadc",
		.data		= (void *)RCAR_GYROADC_MODEL_DEFAULT,
	}, {
		/* R-Car V2H specialty with interrupt registers. */
		.compatible	= "renesas,r8a7792-gyroadc",
		.data		= (void *)RCAR_GYROADC_MODEL_R8A7792,
	}, {
		/* sentinel */
	}
};

MODULE_DEVICE_TABLE(of, rcar_gyroadc_match);

static const struct of_device_id rcar_gyroadc_child_match[] = {
	/* Mode 1 ADCs */
	{
		.compatible	= "fujitsu,mb88101a",
		.data		= (void *)RCAR_GYROADC_MODE_SELECT_1_MB88101A,
	},
	/* Mode 2 ADCs */
	{
		.compatible	= "ti,adcs7476",
		.data		= (void *)RCAR_GYROADC_MODE_SELECT_2_ADCS7476,
	}, {
		.compatible	= "ti,adc121",
		.data		= (void *)RCAR_GYROADC_MODE_SELECT_2_ADCS7476,
	}, {
		.compatible	= "adi,ad7476",
		.data		= (void *)RCAR_GYROADC_MODE_SELECT_2_ADCS7476,
	},
	/* Mode 3 ADCs */
	{
		.compatible	= "maxim,max1162",
		.data		= (void *)RCAR_GYROADC_MODE_SELECT_3_MAX1162,
	}, {
		.compatible	= "maxim,max11100",
		.data		= (void *)RCAR_GYROADC_MODE_SELECT_3_MAX1162,
	},
	{ /* sentinel */ }
};

static int rcar_gyroadc_parse_subdevs(struct iio_dev *indio_dev)
{
	const struct of_device_id *of_id;
	const struct iio_chan_spec *channels;
	struct rcar_gyroadc *priv = iio_priv(indio_dev);
	struct device *dev = priv->dev;
	struct device_node *np = dev->of_node;
	struct device_node *child;
	struct regulator *vref;
	unsigned int reg;
	unsigned int adcmode = -1, childmode;
	unsigned int sample_width;
	unsigned int num_channels;
	int ret, first = 1;

	for_each_child_of_node(np, child) {
		of_id = of_match_node(rcar_gyroadc_child_match, child);
		if (!of_id) {
			dev_err(dev, "Ignoring unsupported ADC \"%s\".",
				child->name);
			continue;
		}

		childmode = (unsigned int)of_id->data;
		switch (childmode) {
		case RCAR_GYROADC_MODE_SELECT_1_MB88101A:
			sample_width = 12;
			channels = rcar_gyroadc_iio_channels_1;
			num_channels = ARRAY_SIZE(rcar_gyroadc_iio_channels_1);
			break;
		case RCAR_GYROADC_MODE_SELECT_2_ADCS7476:
			sample_width = 15;
			channels = rcar_gyroadc_iio_channels_2;
			num_channels = ARRAY_SIZE(rcar_gyroadc_iio_channels_2);
			break;
		case RCAR_GYROADC_MODE_SELECT_3_MAX1162:
			sample_width = 16;
			channels = rcar_gyroadc_iio_channels_3;
			num_channels = ARRAY_SIZE(rcar_gyroadc_iio_channels_3);
			break;
		default:
			return -EINVAL;
		}

		/*
		 * MB88101 is special in that it's only a single chip taking
		 * up all the CHS lines. Thus, the DT binding is also special
		 * and has no reg property. If we run into such ADC, handle
		 * it here.
		 */
		if (childmode == RCAR_GYROADC_MODE_SELECT_1_MB88101A) {
			reg = 0;
		} else {
			ret = of_property_read_u32(child, "reg", &reg);
			if (ret) {
				dev_err(dev,
					"Failed to get child reg property of ADC \"%s\".\n",
					child->name);
				return ret;
			}

			/* Channel number is too high. */
			if (reg >= num_channels) {
				dev_err(dev,
					"Only %i channels supported with %s, but reg = <%i>.\n",
					num_channels, child->name, reg);
				return ret;
			}
		}

		/* Child node selected different mode than the rest. */
		if (!first && (adcmode != childmode)) {
			dev_err(dev,
				"Channel %i uses different ADC mode than the rest.\n",
				reg);
			return ret;
		}

		/* Channel is valid, grab the regulator. */
		dev->of_node = child;
		vref = devm_regulator_get(dev, "vref");
		dev->of_node = np;
		if (IS_ERR(vref)) {
			dev_dbg(dev, "Channel %i 'vref' supply not connected.\n",
				reg);
			return PTR_ERR(vref);
		}

		priv->vref[reg] = vref;

		if (!first)
			continue;

		/* First child node which passed sanity tests. */
		adcmode = childmode;
		first = 0;

		priv->num_channels = num_channels;
		priv->mode = childmode;
		priv->sample_width = sample_width;

		indio_dev->channels = channels;
		indio_dev->num_channels = num_channels;

		/*
		 * MB88101 is special and we only have one such device
		 * attached to the GyroADC at a time, so if we found it,
		 * we can stop parsing here.
		 */
		if (childmode == RCAR_GYROADC_MODE_SELECT_1_MB88101A)
			break;
	}

	if (first) {
		dev_err(dev, "No valid ADC channels found, aborting.\n");
		return -EINVAL;
	}

	return 0;
}

static void rcar_gyroadc_deinit_supplies(struct iio_dev *indio_dev)
{
	struct rcar_gyroadc *priv = iio_priv(indio_dev);
	unsigned int i;

	for (i = 0; i < priv->num_channels; i++) {
		if (!priv->vref[i])
			continue;

		regulator_disable(priv->vref[i]);
	}
}

static int rcar_gyroadc_init_supplies(struct iio_dev *indio_dev)
{
	struct rcar_gyroadc *priv = iio_priv(indio_dev);
	struct device *dev = priv->dev;
	unsigned int i;
	int ret;

	for (i = 0; i < priv->num_channels; i++) {
		if (!priv->vref[i])
			continue;

		ret = regulator_enable(priv->vref[i]);
		if (ret) {
			dev_err(dev, "Failed to enable regulator %i (ret=%i)\n",
				i, ret);
			goto err;
		}
	}

	return 0;

err:
	rcar_gyroadc_deinit_supplies(indio_dev);
	return ret;
}

static int rcar_gyroadc_probe(struct platform_device *pdev)
{
	const struct of_device_id *of_id =
		of_match_device(rcar_gyroadc_match, &pdev->dev);
	struct device *dev = &pdev->dev;
	struct rcar_gyroadc *priv;
	struct iio_dev *indio_dev;
	struct resource *mem;
	int ret;

	indio_dev = devm_iio_device_alloc(dev, sizeof(*priv));
	if (!indio_dev) {
		dev_err(dev, "Failed to allocate IIO device.\n");
		return -ENOMEM;
	}

	priv = iio_priv(indio_dev);
	priv->dev = dev;

	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	priv->regs = devm_ioremap_resource(dev, mem);
	if (IS_ERR(priv->regs))
		return PTR_ERR(priv->regs);

	priv->clk = devm_clk_get(dev, "fck");
	if (IS_ERR(priv->clk)) {
		ret = PTR_ERR(priv->clk);
		if (ret != -EPROBE_DEFER)
			dev_err(dev, "Failed to get IF clock (ret=%i)\n", ret);
		return ret;
	}

	ret = rcar_gyroadc_parse_subdevs(indio_dev);
	if (ret)
		return ret;

	ret = rcar_gyroadc_init_supplies(indio_dev);
	if (ret)
		return ret;

	priv->model = (enum rcar_gyroadc_model)of_id->data;

	platform_set_drvdata(pdev, indio_dev);

	indio_dev->name = DRIVER_NAME;
	indio_dev->dev.parent = dev;
	indio_dev->dev.of_node = pdev->dev.of_node;
	indio_dev->info = &rcar_gyroadc_iio_info;
	indio_dev->modes = INDIO_DIRECT_MODE;

	ret = clk_prepare_enable(priv->clk);
	if (ret) {
		dev_err(dev, "Could not prepare or enable the IF clock.\n");
		goto err_clk_if_enable;
	}

	pm_runtime_set_autosuspend_delay(dev, RCAR_GYROADC_RUNTIME_PM_DELAY_MS);
	pm_runtime_use_autosuspend(dev);
	pm_runtime_enable(dev);

	pm_runtime_get_sync(dev);
	rcar_gyroadc_hw_init(priv);
	rcar_gyroadc_hw_start(priv);

	ret = iio_device_register(indio_dev);
	if (ret) {
		dev_err(dev, "Couldn't register IIO device.\n");
		goto err_iio_device_register;
	}

	pm_runtime_put_sync(dev);

	return 0;

err_iio_device_register:
	rcar_gyroadc_hw_stop(priv);
	pm_runtime_put_sync(dev);
	pm_runtime_disable(dev);
	pm_runtime_set_suspended(dev);
	clk_disable_unprepare(priv->clk);
err_clk_if_enable:
	rcar_gyroadc_deinit_supplies(indio_dev);

	return ret;
}

static int rcar_gyroadc_remove(struct platform_device *pdev)
{
	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
	struct rcar_gyroadc *priv = iio_priv(indio_dev);
	struct device *dev = priv->dev;

	iio_device_unregister(indio_dev);
	pm_runtime_get_sync(dev);
	rcar_gyroadc_hw_stop(priv);
	pm_runtime_put_sync(dev);
	pm_runtime_disable(dev);
	pm_runtime_set_suspended(dev);
	clk_disable_unprepare(priv->clk);
	rcar_gyroadc_deinit_supplies(indio_dev);

	return 0;
}

#if defined(CONFIG_PM)
static int rcar_gyroadc_suspend(struct device *dev)
{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct rcar_gyroadc *priv = iio_priv(indio_dev);

	rcar_gyroadc_hw_stop(priv);

	return 0;
}

static int rcar_gyroadc_resume(struct device *dev)
{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct rcar_gyroadc *priv = iio_priv(indio_dev);

	rcar_gyroadc_hw_start(priv);

	return 0;
}
#endif

static const struct dev_pm_ops rcar_gyroadc_pm_ops = {
	SET_RUNTIME_PM_OPS(rcar_gyroadc_suspend, rcar_gyroadc_resume, NULL)
};

static struct platform_driver rcar_gyroadc_driver = {
	.probe          = rcar_gyroadc_probe,
	.remove         = rcar_gyroadc_remove,
	.driver         = {
		.name		= DRIVER_NAME,
		.of_match_table	= rcar_gyroadc_match,
		.pm		= &rcar_gyroadc_pm_ops,
	},
};

module_platform_driver(rcar_gyroadc_driver);

MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
MODULE_DESCRIPTION("Renesas R-Car GyroADC driver");
MODULE_LICENSE("GPL");