summaryrefslogtreecommitdiffstats
path: root/drivers/iio/adc/rzg2l_adc.c
blob: 5b09a93fdf34fb39af99b0901e52671d2e5b9e81 (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
// SPDX-License-Identifier: GPL-2.0
/*
 * RZ/G2L A/D Converter driver
 *
 *  Copyright (c) 2021 Renesas Electronics Europe GmbH
 *
 * Author: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
 */

#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/iio/iio.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/reset.h>

#define DRIVER_NAME		"rzg2l-adc"

#define RZG2L_ADM(n)			((n) * 0x4)
#define RZG2L_ADM0_ADCE			BIT(0)
#define RZG2L_ADM0_ADBSY		BIT(1)
#define RZG2L_ADM0_PWDWNB		BIT(2)
#define RZG2L_ADM0_SRESB		BIT(15)
#define RZG2L_ADM1_TRG			BIT(0)
#define RZG2L_ADM1_MS			BIT(2)
#define RZG2L_ADM1_BS			BIT(4)
#define RZG2L_ADM1_EGA_MASK		GENMASK(13, 12)
#define RZG2L_ADM2_CHSEL_MASK		GENMASK(7, 0)
#define RZG2L_ADM3_ADIL_MASK		GENMASK(31, 24)
#define RZG2L_ADM3_ADCMP_MASK		GENMASK(23, 16)
#define RZG2L_ADM3_ADCMP_E		FIELD_PREP(RZG2L_ADM3_ADCMP_MASK, 0xe)
#define RZG2L_ADM3_ADSMP_MASK		GENMASK(15, 0)

#define RZG2L_ADINT			0x20
#define RZG2L_ADINT_INTEN_MASK		GENMASK(7, 0)
#define RZG2L_ADINT_CSEEN		BIT(16)
#define RZG2L_ADINT_INTS		BIT(31)

#define RZG2L_ADSTS			0x24
#define RZG2L_ADSTS_CSEST		BIT(16)
#define RZG2L_ADSTS_INTST_MASK		GENMASK(7, 0)

#define RZG2L_ADIVC			0x28
#define RZG2L_ADIVC_DIVADC_MASK		GENMASK(8, 0)
#define RZG2L_ADIVC_DIVADC_4		FIELD_PREP(RZG2L_ADIVC_DIVADC_MASK, 0x4)

#define RZG2L_ADFIL			0x2c

#define RZG2L_ADCR(n)			(0x30 + ((n) * 0x4))
#define RZG2L_ADCR_AD_MASK		GENMASK(11, 0)

#define RZG2L_ADSMP_DEFAULT_SAMPLING	0x578

#define RZG2L_ADC_MAX_CHANNELS		8
#define RZG2L_ADC_CHN_MASK		0x7
#define RZG2L_ADC_TIMEOUT		usecs_to_jiffies(1 * 4)

struct rzg2l_adc_data {
	const struct iio_chan_spec *channels;
	u8 num_channels;
};

struct rzg2l_adc {
	void __iomem *base;
	struct clk *pclk;
	struct clk *adclk;
	struct reset_control *presetn;
	struct reset_control *adrstn;
	struct completion completion;
	const struct rzg2l_adc_data *data;
	struct mutex lock;
	u16 last_val[RZG2L_ADC_MAX_CHANNELS];
};

static const char * const rzg2l_adc_channel_name[] = {
	"adc0",
	"adc1",
	"adc2",
	"adc3",
	"adc4",
	"adc5",
	"adc6",
	"adc7",
};

static unsigned int rzg2l_adc_readl(struct rzg2l_adc *adc, u32 reg)
{
	return readl(adc->base + reg);
}

static void rzg2l_adc_writel(struct rzg2l_adc *adc, unsigned int reg, u32 val)
{
	writel(val, adc->base + reg);
}

static void rzg2l_adc_pwr(struct rzg2l_adc *adc, bool on)
{
	u32 reg;

	reg = rzg2l_adc_readl(adc, RZG2L_ADM(0));
	if (on)
		reg |= RZG2L_ADM0_PWDWNB;
	else
		reg &= ~RZG2L_ADM0_PWDWNB;
	rzg2l_adc_writel(adc, RZG2L_ADM(0), reg);
	udelay(2);
}

static void rzg2l_adc_start_stop(struct rzg2l_adc *adc, bool start)
{
	int timeout = 5;
	u32 reg;

	reg = rzg2l_adc_readl(adc, RZG2L_ADM(0));
	if (start)
		reg |= RZG2L_ADM0_ADCE;
	else
		reg &= ~RZG2L_ADM0_ADCE;
	rzg2l_adc_writel(adc, RZG2L_ADM(0), reg);

	if (start)
		return;

	do {
		usleep_range(100, 200);
		reg = rzg2l_adc_readl(adc, RZG2L_ADM(0));
		timeout--;
		if (!timeout) {
			pr_err("%s stopping ADC timed out\n", __func__);
			break;
		}
	} while (((reg & RZG2L_ADM0_ADBSY) || (reg & RZG2L_ADM0_ADCE)));
}

static void rzg2l_set_trigger(struct rzg2l_adc *adc)
{
	u32 reg;

	/*
	 * Setup ADM1 for SW trigger
	 * EGA[13:12] - Set 00 to indicate hardware trigger is invalid
	 * BS[4] - Enable 1-buffer mode
	 * MS[1] - Enable Select mode
	 * TRG[0] - Enable software trigger mode
	 */
	reg = rzg2l_adc_readl(adc, RZG2L_ADM(1));
	reg &= ~RZG2L_ADM1_EGA_MASK;
	reg &= ~RZG2L_ADM1_BS;
	reg &= ~RZG2L_ADM1_TRG;
	reg |= RZG2L_ADM1_MS;
	rzg2l_adc_writel(adc, RZG2L_ADM(1), reg);
}

static int rzg2l_adc_conversion_setup(struct rzg2l_adc *adc, u8 ch)
{
	u32 reg;

	if (rzg2l_adc_readl(adc, RZG2L_ADM(0)) & RZG2L_ADM0_ADBSY)
		return -EBUSY;

	rzg2l_set_trigger(adc);

	/* Select analog input channel subjected to conversion. */
	reg = rzg2l_adc_readl(adc, RZG2L_ADM(2));
	reg &= ~RZG2L_ADM2_CHSEL_MASK;
	reg |= BIT(ch);
	rzg2l_adc_writel(adc, RZG2L_ADM(2), reg);

	/*
	 * Setup ADINT
	 * INTS[31] - Select pulse signal
	 * CSEEN[16] - Enable channel select error interrupt
	 * INTEN[7:0] - Select channel interrupt
	 */
	reg = rzg2l_adc_readl(adc, RZG2L_ADINT);
	reg &= ~RZG2L_ADINT_INTS;
	reg &= ~RZG2L_ADINT_INTEN_MASK;
	reg |= (RZG2L_ADINT_CSEEN | BIT(ch));
	rzg2l_adc_writel(adc, RZG2L_ADINT, reg);

	return 0;
}

static int rzg2l_adc_set_power(struct iio_dev *indio_dev, bool on)
{
	struct device *dev = indio_dev->dev.parent;

	if (on)
		return pm_runtime_resume_and_get(dev);

	return pm_runtime_put_sync(dev);
}

static int rzg2l_adc_conversion(struct iio_dev *indio_dev, struct rzg2l_adc *adc, u8 ch)
{
	int ret;

	ret = rzg2l_adc_set_power(indio_dev, true);
	if (ret)
		return ret;

	ret = rzg2l_adc_conversion_setup(adc, ch);
	if (ret) {
		rzg2l_adc_set_power(indio_dev, false);
		return ret;
	}

	reinit_completion(&adc->completion);

	rzg2l_adc_start_stop(adc, true);

	if (!wait_for_completion_timeout(&adc->completion, RZG2L_ADC_TIMEOUT)) {
		rzg2l_adc_writel(adc, RZG2L_ADINT,
				 rzg2l_adc_readl(adc, RZG2L_ADINT) & ~RZG2L_ADINT_INTEN_MASK);
		rzg2l_adc_start_stop(adc, false);
		rzg2l_adc_set_power(indio_dev, false);
		return -ETIMEDOUT;
	}

	return rzg2l_adc_set_power(indio_dev, false);
}

static int rzg2l_adc_read_raw(struct iio_dev *indio_dev,
			      struct iio_chan_spec const *chan,
			      int *val, int *val2, long mask)
{
	struct rzg2l_adc *adc = iio_priv(indio_dev);
	int ret;
	u8 ch;

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

		mutex_lock(&adc->lock);
		ch = chan->channel & RZG2L_ADC_CHN_MASK;
		ret = rzg2l_adc_conversion(indio_dev, adc, ch);
		if (ret) {
			mutex_unlock(&adc->lock);
			return ret;
		}
		*val = adc->last_val[ch];
		mutex_unlock(&adc->lock);

		return IIO_VAL_INT;

	default:
		return -EINVAL;
	}
}

static int rzg2l_adc_read_label(struct iio_dev *iio_dev,
				const struct iio_chan_spec *chan,
				char *label)
{
	if (chan->channel >= RZG2L_ADC_MAX_CHANNELS)
		return -EINVAL;

	return sysfs_emit(label, "%s\n", rzg2l_adc_channel_name[chan->channel]);
}

static const struct iio_info rzg2l_adc_iio_info = {
	.read_raw = rzg2l_adc_read_raw,
	.read_label = rzg2l_adc_read_label,
};

static irqreturn_t rzg2l_adc_isr(int irq, void *dev_id)
{
	struct rzg2l_adc *adc = dev_id;
	unsigned long intst;
	u32 reg;
	int ch;

	reg = rzg2l_adc_readl(adc, RZG2L_ADSTS);

	/* A/D conversion channel select error interrupt */
	if (reg & RZG2L_ADSTS_CSEST) {
		rzg2l_adc_writel(adc, RZG2L_ADSTS, reg);
		return IRQ_HANDLED;
	}

	intst = reg & RZG2L_ADSTS_INTST_MASK;
	if (!intst)
		return IRQ_NONE;

	for_each_set_bit(ch, &intst, RZG2L_ADC_MAX_CHANNELS)
		adc->last_val[ch] = rzg2l_adc_readl(adc, RZG2L_ADCR(ch)) & RZG2L_ADCR_AD_MASK;

	/* clear the channel interrupt */
	rzg2l_adc_writel(adc, RZG2L_ADSTS, reg);

	complete(&adc->completion);

	return IRQ_HANDLED;
}

static int rzg2l_adc_parse_properties(struct platform_device *pdev, struct rzg2l_adc *adc)
{
	struct iio_chan_spec *chan_array;
	struct fwnode_handle *fwnode;
	struct rzg2l_adc_data *data;
	unsigned int channel;
	int num_channels;
	int ret;
	u8 i;

	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	num_channels = device_get_child_node_count(&pdev->dev);
	if (!num_channels) {
		dev_err(&pdev->dev, "no channel children\n");
		return -ENODEV;
	}

	if (num_channels > RZG2L_ADC_MAX_CHANNELS) {
		dev_err(&pdev->dev, "num of channel children out of range\n");
		return -EINVAL;
	}

	chan_array = devm_kcalloc(&pdev->dev, num_channels, sizeof(*chan_array),
				  GFP_KERNEL);
	if (!chan_array)
		return -ENOMEM;

	i = 0;
	device_for_each_child_node(&pdev->dev, fwnode) {
		ret = fwnode_property_read_u32(fwnode, "reg", &channel);
		if (ret) {
			fwnode_handle_put(fwnode);
			return ret;
		}

		if (channel >= RZG2L_ADC_MAX_CHANNELS) {
			fwnode_handle_put(fwnode);
			return -EINVAL;
		}

		chan_array[i].type = IIO_VOLTAGE;
		chan_array[i].indexed = 1;
		chan_array[i].channel = channel;
		chan_array[i].info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
		chan_array[i].datasheet_name = rzg2l_adc_channel_name[channel];
		i++;
	}

	data->num_channels = num_channels;
	data->channels = chan_array;
	adc->data = data;

	return 0;
}

static int rzg2l_adc_hw_init(struct rzg2l_adc *adc)
{
	int timeout = 5;
	u32 reg;
	int ret;

	ret = clk_prepare_enable(adc->pclk);
	if (ret)
		return ret;

	/* SW reset */
	reg = rzg2l_adc_readl(adc, RZG2L_ADM(0));
	reg |= RZG2L_ADM0_SRESB;
	rzg2l_adc_writel(adc, RZG2L_ADM(0), reg);

	while (!(rzg2l_adc_readl(adc, RZG2L_ADM(0)) & RZG2L_ADM0_SRESB)) {
		if (!timeout) {
			ret = -EBUSY;
			goto exit_hw_init;
		}
		timeout--;
		usleep_range(100, 200);
	}

	/* Only division by 4 can be set */
	reg = rzg2l_adc_readl(adc, RZG2L_ADIVC);
	reg &= ~RZG2L_ADIVC_DIVADC_MASK;
	reg |= RZG2L_ADIVC_DIVADC_4;
	rzg2l_adc_writel(adc, RZG2L_ADIVC, reg);

	/*
	 * Setup AMD3
	 * ADIL[31:24] - Should be always set to 0
	 * ADCMP[23:16] - Should be always set to 0xe
	 * ADSMP[15:0] - Set default (0x578) sampling period
	 */
	reg = rzg2l_adc_readl(adc, RZG2L_ADM(3));
	reg &= ~RZG2L_ADM3_ADIL_MASK;
	reg &= ~RZG2L_ADM3_ADCMP_MASK;
	reg &= ~RZG2L_ADM3_ADSMP_MASK;
	reg |= (RZG2L_ADM3_ADCMP_E | RZG2L_ADSMP_DEFAULT_SAMPLING);
	rzg2l_adc_writel(adc, RZG2L_ADM(3), reg);

exit_hw_init:
	clk_disable_unprepare(adc->pclk);

	return ret;
}

static void rzg2l_adc_pm_runtime_disable(void *data)
{
	struct device *dev = data;

	pm_runtime_disable(dev->parent);
}

static void rzg2l_adc_pm_runtime_set_suspended(void *data)
{
	struct device *dev = data;

	pm_runtime_set_suspended(dev->parent);
}

static void rzg2l_adc_reset_assert(void *data)
{
	reset_control_assert(data);
}

static int rzg2l_adc_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct iio_dev *indio_dev;
	struct rzg2l_adc *adc;
	int ret;
	int irq;

	indio_dev = devm_iio_device_alloc(dev, sizeof(*adc));
	if (!indio_dev)
		return -ENOMEM;

	adc = iio_priv(indio_dev);

	ret = rzg2l_adc_parse_properties(pdev, adc);
	if (ret)
		return ret;

	mutex_init(&adc->lock);

	adc->base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(adc->base))
		return PTR_ERR(adc->base);

	adc->pclk = devm_clk_get(dev, "pclk");
	if (IS_ERR(adc->pclk)) {
		dev_err(dev, "Failed to get pclk");
		return PTR_ERR(adc->pclk);
	}

	adc->adclk = devm_clk_get(dev, "adclk");
	if (IS_ERR(adc->adclk)) {
		dev_err(dev, "Failed to get adclk");
		return PTR_ERR(adc->adclk);
	}

	adc->adrstn = devm_reset_control_get_exclusive(dev, "adrst-n");
	if (IS_ERR(adc->adrstn)) {
		dev_err(dev, "failed to get adrstn\n");
		return PTR_ERR(adc->adrstn);
	}

	adc->presetn = devm_reset_control_get_exclusive(dev, "presetn");
	if (IS_ERR(adc->presetn)) {
		dev_err(dev, "failed to get presetn\n");
		return PTR_ERR(adc->presetn);
	}

	ret = reset_control_deassert(adc->adrstn);
	if (ret) {
		dev_err(&pdev->dev, "failed to deassert adrstn pin, %d\n", ret);
		return ret;
	}

	ret = devm_add_action_or_reset(&pdev->dev,
				       rzg2l_adc_reset_assert, adc->adrstn);
	if (ret) {
		dev_err(&pdev->dev, "failed to register adrstn assert devm action, %d\n",
			ret);
		return ret;
	}

	ret = reset_control_deassert(adc->presetn);
	if (ret) {
		dev_err(&pdev->dev, "failed to deassert presetn pin, %d\n", ret);
		return ret;
	}

	ret = devm_add_action_or_reset(&pdev->dev,
				       rzg2l_adc_reset_assert, adc->presetn);
	if (ret) {
		dev_err(&pdev->dev, "failed to register presetn assert devm action, %d\n",
			ret);
		return ret;
	}

	ret = rzg2l_adc_hw_init(adc);
	if (ret) {
		dev_err(&pdev->dev, "failed to initialize ADC HW, %d\n", ret);
		return ret;
	}

	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
		return irq;

	ret = devm_request_irq(dev, irq, rzg2l_adc_isr,
			       0, dev_name(dev), adc);
	if (ret < 0)
		return ret;

	init_completion(&adc->completion);

	platform_set_drvdata(pdev, indio_dev);

	indio_dev->name = DRIVER_NAME;
	indio_dev->info = &rzg2l_adc_iio_info;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = adc->data->channels;
	indio_dev->num_channels = adc->data->num_channels;

	pm_runtime_set_suspended(dev);
	ret = devm_add_action_or_reset(&pdev->dev,
				       rzg2l_adc_pm_runtime_set_suspended, &indio_dev->dev);
	if (ret)
		return ret;

	pm_runtime_enable(dev);
	ret = devm_add_action_or_reset(&pdev->dev,
				       rzg2l_adc_pm_runtime_disable, &indio_dev->dev);
	if (ret)
		return ret;

	return devm_iio_device_register(dev, indio_dev);
}

static const struct of_device_id rzg2l_adc_match[] = {
	{ .compatible = "renesas,rzg2l-adc",},
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, rzg2l_adc_match);

static int __maybe_unused rzg2l_adc_pm_runtime_suspend(struct device *dev)
{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct rzg2l_adc *adc = iio_priv(indio_dev);

	rzg2l_adc_pwr(adc, false);
	clk_disable_unprepare(adc->adclk);
	clk_disable_unprepare(adc->pclk);

	return 0;
}

static int __maybe_unused rzg2l_adc_pm_runtime_resume(struct device *dev)
{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct rzg2l_adc *adc = iio_priv(indio_dev);
	int ret;

	ret = clk_prepare_enable(adc->pclk);
	if (ret)
		return ret;

	ret = clk_prepare_enable(adc->adclk);
	if (ret) {
		clk_disable_unprepare(adc->pclk);
		return ret;
	}

	rzg2l_adc_pwr(adc, true);

	return 0;
}

static const struct dev_pm_ops rzg2l_adc_pm_ops = {
	SET_RUNTIME_PM_OPS(rzg2l_adc_pm_runtime_suspend,
			   rzg2l_adc_pm_runtime_resume,
			   NULL)
};

static struct platform_driver rzg2l_adc_driver = {
	.probe		= rzg2l_adc_probe,
	.driver		= {
		.name		= DRIVER_NAME,
		.of_match_table = rzg2l_adc_match,
		.pm		= &rzg2l_adc_pm_ops,
	},
};

module_platform_driver(rzg2l_adc_driver);

MODULE_AUTHOR("Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>");
MODULE_DESCRIPTION("Renesas RZ/G2L ADC driver");
MODULE_LICENSE("GPL v2");