summaryrefslogtreecommitdiffstats
path: root/drivers/iio/adc/rockchip_saradc.c
blob: 79448c5ffc2ae2d4306026dd879e978a4f709214 (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
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Rockchip Successive Approximation Register (SAR) A/D Converter
 * Copyright (C) 2014 ROCKCHIP, Inc.
 */

#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/reset.h>
#include <linux/regulator/consumer.h>
#include <linux/iio/buffer.h>
#include <linux/iio/iio.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>

#define SARADC_DATA			0x00

#define SARADC_STAS			0x04
#define SARADC_STAS_BUSY		BIT(0)

#define SARADC_CTRL			0x08
#define SARADC_CTRL_IRQ_STATUS		BIT(6)
#define SARADC_CTRL_IRQ_ENABLE		BIT(5)
#define SARADC_CTRL_POWER_CTRL		BIT(3)
#define SARADC_CTRL_CHN_MASK		0x7

#define SARADC_DLY_PU_SOC		0x0c
#define SARADC_DLY_PU_SOC_MASK		0x3f

#define SARADC_TIMEOUT			msecs_to_jiffies(100)
#define SARADC_MAX_CHANNELS		8

struct rockchip_saradc_data {
	const struct iio_chan_spec	*channels;
	int				num_channels;
	unsigned long			clk_rate;
};

struct rockchip_saradc {
	void __iomem		*regs;
	struct clk		*pclk;
	struct clk		*clk;
	struct completion	completion;
	struct regulator	*vref;
	/* lock to protect against multiple access to the device */
	struct mutex		lock;
	int			uv_vref;
	struct reset_control	*reset;
	const struct rockchip_saradc_data *data;
	u16			last_val;
	const struct iio_chan_spec *last_chan;
	struct notifier_block nb;
};

static void rockchip_saradc_power_down(struct rockchip_saradc *info)
{
	/* Clear irq & power down adc */
	writel_relaxed(0, info->regs + SARADC_CTRL);
}

static int rockchip_saradc_conversion(struct rockchip_saradc *info,
				   struct iio_chan_spec const *chan)
{
	reinit_completion(&info->completion);

	/* 8 clock periods as delay between power up and start cmd */
	writel_relaxed(8, info->regs + SARADC_DLY_PU_SOC);

	info->last_chan = chan;

	/* Select the channel to be used and trigger conversion */
	writel(SARADC_CTRL_POWER_CTRL
			| (chan->channel & SARADC_CTRL_CHN_MASK)
			| SARADC_CTRL_IRQ_ENABLE,
		   info->regs + SARADC_CTRL);

	if (!wait_for_completion_timeout(&info->completion, SARADC_TIMEOUT))
		return -ETIMEDOUT;

	return 0;
}

static int rockchip_saradc_read_raw(struct iio_dev *indio_dev,
				    struct iio_chan_spec const *chan,
				    int *val, int *val2, long mask)
{
	struct rockchip_saradc *info = iio_priv(indio_dev);
	int ret;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		mutex_lock(&info->lock);

		ret = rockchip_saradc_conversion(info, chan);
		if (ret) {
			rockchip_saradc_power_down(info);
			mutex_unlock(&info->lock);
			return ret;
		}

		*val = info->last_val;
		mutex_unlock(&info->lock);
		return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
		*val = info->uv_vref / 1000;
		*val2 = chan->scan_type.realbits;
		return IIO_VAL_FRACTIONAL_LOG2;
	default:
		return -EINVAL;
	}
}

static irqreturn_t rockchip_saradc_isr(int irq, void *dev_id)
{
	struct rockchip_saradc *info = dev_id;

	/* Read value */
	info->last_val = readl_relaxed(info->regs + SARADC_DATA);
	info->last_val &= GENMASK(info->last_chan->scan_type.realbits - 1, 0);

	rockchip_saradc_power_down(info);

	complete(&info->completion);

	return IRQ_HANDLED;
}

static const struct iio_info rockchip_saradc_iio_info = {
	.read_raw = rockchip_saradc_read_raw,
};

#define SARADC_CHANNEL(_index, _id, _res) {			\
	.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,					\
	.scan_index = _index,					\
	.scan_type = {						\
		.sign = 'u',					\
		.realbits = _res,				\
		.storagebits = 16,				\
		.endianness = IIO_CPU,				\
	},							\
}

static const struct iio_chan_spec rockchip_saradc_iio_channels[] = {
	SARADC_CHANNEL(0, "adc0", 10),
	SARADC_CHANNEL(1, "adc1", 10),
	SARADC_CHANNEL(2, "adc2", 10),
};

static const struct rockchip_saradc_data saradc_data = {
	.channels = rockchip_saradc_iio_channels,
	.num_channels = ARRAY_SIZE(rockchip_saradc_iio_channels),
	.clk_rate = 1000000,
};

static const struct iio_chan_spec rockchip_rk3066_tsadc_iio_channels[] = {
	SARADC_CHANNEL(0, "adc0", 12),
	SARADC_CHANNEL(1, "adc1", 12),
};

static const struct rockchip_saradc_data rk3066_tsadc_data = {
	.channels = rockchip_rk3066_tsadc_iio_channels,
	.num_channels = ARRAY_SIZE(rockchip_rk3066_tsadc_iio_channels),
	.clk_rate = 50000,
};

static const struct iio_chan_spec rockchip_rk3399_saradc_iio_channels[] = {
	SARADC_CHANNEL(0, "adc0", 10),
	SARADC_CHANNEL(1, "adc1", 10),
	SARADC_CHANNEL(2, "adc2", 10),
	SARADC_CHANNEL(3, "adc3", 10),
	SARADC_CHANNEL(4, "adc4", 10),
	SARADC_CHANNEL(5, "adc5", 10),
};

static const struct rockchip_saradc_data rk3399_saradc_data = {
	.channels = rockchip_rk3399_saradc_iio_channels,
	.num_channels = ARRAY_SIZE(rockchip_rk3399_saradc_iio_channels),
	.clk_rate = 1000000,
};

static const struct iio_chan_spec rockchip_rk3568_saradc_iio_channels[] = {
	SARADC_CHANNEL(0, "adc0", 10),
	SARADC_CHANNEL(1, "adc1", 10),
	SARADC_CHANNEL(2, "adc2", 10),
	SARADC_CHANNEL(3, "adc3", 10),
	SARADC_CHANNEL(4, "adc4", 10),
	SARADC_CHANNEL(5, "adc5", 10),
	SARADC_CHANNEL(6, "adc6", 10),
	SARADC_CHANNEL(7, "adc7", 10),
};

static const struct rockchip_saradc_data rk3568_saradc_data = {
	.channels = rockchip_rk3568_saradc_iio_channels,
	.num_channels = ARRAY_SIZE(rockchip_rk3568_saradc_iio_channels),
	.clk_rate = 1000000,
};

static const struct of_device_id rockchip_saradc_match[] = {
	{
		.compatible = "rockchip,saradc",
		.data = &saradc_data,
	}, {
		.compatible = "rockchip,rk3066-tsadc",
		.data = &rk3066_tsadc_data,
	}, {
		.compatible = "rockchip,rk3399-saradc",
		.data = &rk3399_saradc_data,
	}, {
		.compatible = "rockchip,rk3568-saradc",
		.data = &rk3568_saradc_data,
	},
	{},
};
MODULE_DEVICE_TABLE(of, rockchip_saradc_match);

/*
 * Reset SARADC Controller.
 */
static void rockchip_saradc_reset_controller(struct reset_control *reset)
{
	reset_control_assert(reset);
	usleep_range(10, 20);
	reset_control_deassert(reset);
}

static void rockchip_saradc_clk_disable(void *data)
{
	struct rockchip_saradc *info = data;

	clk_disable_unprepare(info->clk);
}

static void rockchip_saradc_pclk_disable(void *data)
{
	struct rockchip_saradc *info = data;

	clk_disable_unprepare(info->pclk);
}

static void rockchip_saradc_regulator_disable(void *data)
{
	struct rockchip_saradc *info = data;

	regulator_disable(info->vref);
}

static irqreturn_t rockchip_saradc_trigger_handler(int irq, void *p)
{
	struct iio_poll_func *pf = p;
	struct iio_dev *i_dev = pf->indio_dev;
	struct rockchip_saradc *info = iio_priv(i_dev);
	/*
	 * @values: each channel takes an u16 value
	 * @timestamp: will be 8-byte aligned automatically
	 */
	struct {
		u16 values[SARADC_MAX_CHANNELS];
		int64_t timestamp;
	} data;
	int ret;
	int i, j = 0;

	mutex_lock(&info->lock);

	for_each_set_bit(i, i_dev->active_scan_mask, i_dev->masklength) {
		const struct iio_chan_spec *chan = &i_dev->channels[i];

		ret = rockchip_saradc_conversion(info, chan);
		if (ret) {
			rockchip_saradc_power_down(info);
			goto out;
		}

		data.values[j] = info->last_val;
		j++;
	}

	iio_push_to_buffers_with_timestamp(i_dev, &data, iio_get_time_ns(i_dev));
out:
	mutex_unlock(&info->lock);

	iio_trigger_notify_done(i_dev->trig);

	return IRQ_HANDLED;
}

static int rockchip_saradc_volt_notify(struct notifier_block *nb,
						   unsigned long event,
						   void *data)
{
	struct rockchip_saradc *info =
			container_of(nb, struct rockchip_saradc, nb);

	if (event & REGULATOR_EVENT_VOLTAGE_CHANGE)
		info->uv_vref = (unsigned long)data;

	return NOTIFY_OK;
}

static void rockchip_saradc_regulator_unreg_notifier(void *data)
{
	struct rockchip_saradc *info = data;

	regulator_unregister_notifier(info->vref, &info->nb);
}

static int rockchip_saradc_probe(struct platform_device *pdev)
{
	struct rockchip_saradc *info = NULL;
	struct device_node *np = pdev->dev.of_node;
	struct iio_dev *indio_dev = NULL;
	const struct of_device_id *match;
	int ret;
	int irq;

	if (!np)
		return -ENODEV;

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

	match = of_match_device(rockchip_saradc_match, &pdev->dev);
	if (!match) {
		dev_err(&pdev->dev, "failed to match device\n");
		return -ENODEV;
	}

	info->data = match->data;

	/* Sanity check for possible later IP variants with more channels */
	if (info->data->num_channels > SARADC_MAX_CHANNELS) {
		dev_err(&pdev->dev, "max channels exceeded");
		return -EINVAL;
	}

	info->regs = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(info->regs))
		return PTR_ERR(info->regs);

	/*
	 * The reset should be an optional property, as it should work
	 * with old devicetrees as well
	 */
	info->reset = devm_reset_control_get_exclusive(&pdev->dev,
						       "saradc-apb");
	if (IS_ERR(info->reset)) {
		ret = PTR_ERR(info->reset);
		if (ret != -ENOENT)
			return dev_err_probe(&pdev->dev, ret,
					     "failed to get saradc-apb\n");

		dev_dbg(&pdev->dev, "no reset control found\n");
		info->reset = NULL;
	}

	init_completion(&info->completion);

	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
		return dev_err_probe(&pdev->dev, irq, "failed to get irq\n");

	ret = devm_request_irq(&pdev->dev, irq, rockchip_saradc_isr,
			       0, dev_name(&pdev->dev), info);
	if (ret < 0) {
		dev_err(&pdev->dev, "failed requesting irq %d\n", irq);
		return ret;
	}

	info->pclk = devm_clk_get(&pdev->dev, "apb_pclk");
	if (IS_ERR(info->pclk))
		return dev_err_probe(&pdev->dev, PTR_ERR(info->pclk),
				     "failed to get pclk\n");

	info->clk = devm_clk_get(&pdev->dev, "saradc");
	if (IS_ERR(info->clk))
		return dev_err_probe(&pdev->dev, PTR_ERR(info->clk),
				     "failed to get adc clock\n");

	info->vref = devm_regulator_get(&pdev->dev, "vref");
	if (IS_ERR(info->vref))
		return dev_err_probe(&pdev->dev, PTR_ERR(info->vref),
				     "failed to get regulator\n");

	if (info->reset)
		rockchip_saradc_reset_controller(info->reset);

	/*
	 * Use a default value for the converter clock.
	 * This may become user-configurable in the future.
	 */
	ret = clk_set_rate(info->clk, info->data->clk_rate);
	if (ret < 0) {
		dev_err(&pdev->dev, "failed to set adc clk rate, %d\n", ret);
		return ret;
	}

	ret = regulator_enable(info->vref);
	if (ret < 0) {
		dev_err(&pdev->dev, "failed to enable vref regulator\n");
		return ret;
	}
	ret = devm_add_action_or_reset(&pdev->dev,
				       rockchip_saradc_regulator_disable, info);
	if (ret) {
		dev_err(&pdev->dev, "failed to register devm action, %d\n",
			ret);
		return ret;
	}

	ret = regulator_get_voltage(info->vref);
	if (ret < 0)
		return ret;

	info->uv_vref = ret;

	ret = clk_prepare_enable(info->pclk);
	if (ret < 0) {
		dev_err(&pdev->dev, "failed to enable pclk\n");
		return ret;
	}
	ret = devm_add_action_or_reset(&pdev->dev,
				       rockchip_saradc_pclk_disable, info);
	if (ret) {
		dev_err(&pdev->dev, "failed to register devm action, %d\n",
			ret);
		return ret;
	}

	ret = clk_prepare_enable(info->clk);
	if (ret < 0) {
		dev_err(&pdev->dev, "failed to enable converter clock\n");
		return ret;
	}
	ret = devm_add_action_or_reset(&pdev->dev,
				       rockchip_saradc_clk_disable, info);
	if (ret) {
		dev_err(&pdev->dev, "failed to register devm action, %d\n",
			ret);
		return ret;
	}

	platform_set_drvdata(pdev, indio_dev);

	indio_dev->name = dev_name(&pdev->dev);
	indio_dev->info = &rockchip_saradc_iio_info;
	indio_dev->modes = INDIO_DIRECT_MODE;

	indio_dev->channels = info->data->channels;
	indio_dev->num_channels = info->data->num_channels;
	ret = devm_iio_triggered_buffer_setup(&indio_dev->dev, indio_dev, NULL,
					      rockchip_saradc_trigger_handler,
					      NULL);
	if (ret)
		return ret;

	info->nb.notifier_call = rockchip_saradc_volt_notify;
	ret = regulator_register_notifier(info->vref, &info->nb);
	if (ret)
		return ret;

	ret = devm_add_action_or_reset(&pdev->dev,
				       rockchip_saradc_regulator_unreg_notifier,
				       info);
	if (ret)
		return ret;

	mutex_init(&info->lock);

	return devm_iio_device_register(&pdev->dev, indio_dev);
}

static int rockchip_saradc_suspend(struct device *dev)
{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct rockchip_saradc *info = iio_priv(indio_dev);

	clk_disable_unprepare(info->clk);
	clk_disable_unprepare(info->pclk);
	regulator_disable(info->vref);

	return 0;
}

static int rockchip_saradc_resume(struct device *dev)
{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct rockchip_saradc *info = iio_priv(indio_dev);
	int ret;

	ret = regulator_enable(info->vref);
	if (ret)
		return ret;

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

	ret = clk_prepare_enable(info->clk);
	if (ret)
		clk_disable_unprepare(info->pclk);

	return ret;
}

static DEFINE_SIMPLE_DEV_PM_OPS(rockchip_saradc_pm_ops,
				rockchip_saradc_suspend,
				rockchip_saradc_resume);

static struct platform_driver rockchip_saradc_driver = {
	.probe		= rockchip_saradc_probe,
	.driver		= {
		.name	= "rockchip-saradc",
		.of_match_table = rockchip_saradc_match,
		.pm	= pm_sleep_ptr(&rockchip_saradc_pm_ops),
	},
};

module_platform_driver(rockchip_saradc_driver);

MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
MODULE_DESCRIPTION("Rockchip SARADC driver");
MODULE_LICENSE("GPL v2");