summaryrefslogtreecommitdiff
path: root/drivers/iio/dac/ad5761.c
blob: 6aa1a068adb06172278d1e8d8a030ab20289461e (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
// SPDX-License-Identifier: GPL-2.0-only
/*
 * AD5721, AD5721R, AD5761, AD5761R, Voltage Output Digital to Analog Converter
 *
 * Copyright 2016 Qtechnology A/S
 * 2016 Ricardo Ribalda <ribalda@kernel.org>
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/spi/spi.h>
#include <linux/bitops.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/regulator/consumer.h>
#include <linux/platform_data/ad5761.h>

#define AD5761_ADDR(addr)		((addr & 0xf) << 16)
#define AD5761_ADDR_NOOP		0x0
#define AD5761_ADDR_DAC_WRITE		0x3
#define AD5761_ADDR_CTRL_WRITE_REG	0x4
#define AD5761_ADDR_SW_DATA_RESET	0x7
#define AD5761_ADDR_DAC_READ		0xb
#define AD5761_ADDR_CTRL_READ_REG	0xc
#define AD5761_ADDR_SW_FULL_RESET	0xf

#define AD5761_CTRL_USE_INTVREF		BIT(5)
#define AD5761_CTRL_ETS			BIT(6)

/**
 * struct ad5761_chip_info - chip specific information
 * @int_vref:	Value of the internal reference voltage in mV - 0 if external
 *		reference voltage is used
 * @channel:	channel specification
*/

struct ad5761_chip_info {
	unsigned long int_vref;
	const struct iio_chan_spec channel;
};

struct ad5761_range_params {
	int m;
	int c;
};

enum ad5761_supported_device_ids {
	ID_AD5721,
	ID_AD5721R,
	ID_AD5761,
	ID_AD5761R,
};

/**
 * struct ad5761_state - driver instance specific data
 * @spi:		spi_device
 * @vref_reg:		reference voltage regulator
 * @use_intref:		true when the internal voltage reference is used
 * @vref:		actual voltage reference in mVolts
 * @range:		output range mode used
 * @lock:		lock to protect the data buffer during SPI ops
 * @data:		cache aligned spi buffer
 */
struct ad5761_state {
	struct spi_device		*spi;
	struct regulator		*vref_reg;
	struct mutex			lock;

	bool use_intref;
	int vref;
	enum ad5761_voltage_range range;

	/*
	 * DMA (thus cache coherency maintenance) may require the
	 * transfer buffers to live in their own cache lines.
	 */
	union {
		__be32 d32;
		u8 d8[4];
	} data[3] __aligned(IIO_DMA_MINALIGN);
};

static const struct ad5761_range_params ad5761_range_params[] = {
	[AD5761_VOLTAGE_RANGE_M10V_10V] = {
		.m = 80,
		.c = 40,
	},
	[AD5761_VOLTAGE_RANGE_0V_10V] = {
		.m = 40,
		.c = 0,
	},
	[AD5761_VOLTAGE_RANGE_M5V_5V] = {
		.m = 40,
		.c = 20,
	},
	[AD5761_VOLTAGE_RANGE_0V_5V] = {
		.m = 20,
		.c = 0,
	},
	[AD5761_VOLTAGE_RANGE_M2V5_7V5] = {
		.m = 40,
		.c = 10,
	},
	[AD5761_VOLTAGE_RANGE_M3V_3V] = {
		.m = 24,
		.c = 12,
	},
	[AD5761_VOLTAGE_RANGE_0V_16V] = {
		.m = 64,
		.c = 0,
	},
	[AD5761_VOLTAGE_RANGE_0V_20V] = {
		.m = 80,
		.c = 0,
	},
};

static int _ad5761_spi_write(struct ad5761_state *st, u8 addr, u16 val)
{
	st->data[0].d32 = cpu_to_be32(AD5761_ADDR(addr) | val);

	return spi_write(st->spi, &st->data[0].d8[1], 3);
}

static int ad5761_spi_write(struct iio_dev *indio_dev, u8 addr, u16 val)
{
	struct ad5761_state *st = iio_priv(indio_dev);
	int ret;

	mutex_lock(&st->lock);
	ret = _ad5761_spi_write(st, addr, val);
	mutex_unlock(&st->lock);

	return ret;
}

static int _ad5761_spi_read(struct ad5761_state *st, u8 addr, u16 *val)
{
	int ret;
	struct spi_transfer xfers[] = {
		{
			.tx_buf = &st->data[0].d8[1],
			.bits_per_word = 8,
			.len = 3,
			.cs_change = true,
		}, {
			.tx_buf = &st->data[1].d8[1],
			.rx_buf = &st->data[2].d8[1],
			.bits_per_word = 8,
			.len = 3,
		},
	};

	st->data[0].d32 = cpu_to_be32(AD5761_ADDR(addr));
	st->data[1].d32 = cpu_to_be32(AD5761_ADDR(AD5761_ADDR_NOOP));

	ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers));

	*val = be32_to_cpu(st->data[2].d32);

	return ret;
}

static int ad5761_spi_read(struct iio_dev *indio_dev, u8 addr, u16 *val)
{
	struct ad5761_state *st = iio_priv(indio_dev);
	int ret;

	mutex_lock(&st->lock);
	ret = _ad5761_spi_read(st, addr, val);
	mutex_unlock(&st->lock);

	return ret;
}

static int ad5761_spi_set_range(struct ad5761_state *st,
				enum ad5761_voltage_range range)
{
	u16 aux;
	int ret;

	aux = (range & 0x7) | AD5761_CTRL_ETS;

	if (st->use_intref)
		aux |= AD5761_CTRL_USE_INTVREF;

	ret = _ad5761_spi_write(st, AD5761_ADDR_SW_FULL_RESET, 0);
	if (ret)
		return ret;

	ret = _ad5761_spi_write(st, AD5761_ADDR_CTRL_WRITE_REG, aux);
	if (ret)
		return ret;

	st->range = range;

	return 0;
}

static int ad5761_read_raw(struct iio_dev *indio_dev,
			   struct iio_chan_spec const *chan,
			   int *val,
			   int *val2,
			   long mask)
{
	struct ad5761_state *st;
	int ret;
	u16 aux;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		ret = ad5761_spi_read(indio_dev, AD5761_ADDR_DAC_READ, &aux);
		if (ret)
			return ret;
		*val = aux >> chan->scan_type.shift;
		return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
		st = iio_priv(indio_dev);
		*val = st->vref * ad5761_range_params[st->range].m;
		*val /= 10;
		*val2 = chan->scan_type.realbits;
		return IIO_VAL_FRACTIONAL_LOG2;
	case IIO_CHAN_INFO_OFFSET:
		st = iio_priv(indio_dev);
		*val = -(1 << chan->scan_type.realbits);
		*val *=	ad5761_range_params[st->range].c;
		*val /=	ad5761_range_params[st->range].m;
		return IIO_VAL_INT;
	default:
		return -EINVAL;
	}
}

static int ad5761_write_raw(struct iio_dev *indio_dev,
			    struct iio_chan_spec const *chan,
			    int val,
			    int val2,
			    long mask)
{
	u16 aux;

	if (mask != IIO_CHAN_INFO_RAW)
		return -EINVAL;

	if (val2 || (val << chan->scan_type.shift) > 0xffff || val < 0)
		return -EINVAL;

	aux = val << chan->scan_type.shift;

	return ad5761_spi_write(indio_dev, AD5761_ADDR_DAC_WRITE, aux);
}

static const struct iio_info ad5761_info = {
	.read_raw = &ad5761_read_raw,
	.write_raw = &ad5761_write_raw,
};

#define AD5761_CHAN(_bits) {				\
	.type = IIO_VOLTAGE,				\
	.output = 1,					\
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |	\
		BIT(IIO_CHAN_INFO_OFFSET),		\
	.scan_type = {					\
		.sign = 'u',				\
		.realbits = (_bits),			\
		.storagebits = 16,			\
		.shift = 16 - (_bits),			\
	},						\
}

static const struct ad5761_chip_info ad5761_chip_infos[] = {
	[ID_AD5721] = {
		.int_vref = 0,
		.channel = AD5761_CHAN(12),
	},
	[ID_AD5721R] = {
		.int_vref = 2500,
		.channel = AD5761_CHAN(12),
	},
	[ID_AD5761] = {
		.int_vref = 0,
		.channel = AD5761_CHAN(16),
	},
	[ID_AD5761R] = {
		.int_vref = 2500,
		.channel = AD5761_CHAN(16),
	},
};

static int ad5761_get_vref(struct ad5761_state *st,
			   const struct ad5761_chip_info *chip_info)
{
	int ret;

	st->vref_reg = devm_regulator_get_optional(&st->spi->dev, "vref");
	if (PTR_ERR(st->vref_reg) == -ENODEV) {
		/* Use Internal regulator */
		if (!chip_info->int_vref) {
			dev_err(&st->spi->dev,
				"Voltage reference not found\n");
			return -EIO;
		}

		st->use_intref = true;
		st->vref = chip_info->int_vref;
		return 0;
	}

	if (IS_ERR(st->vref_reg)) {
		dev_err(&st->spi->dev,
			"Error getting voltage reference regulator\n");
		return PTR_ERR(st->vref_reg);
	}

	ret = regulator_enable(st->vref_reg);
	if (ret) {
		dev_err(&st->spi->dev,
			 "Failed to enable voltage reference\n");
		return ret;
	}

	ret = regulator_get_voltage(st->vref_reg);
	if (ret < 0) {
		dev_err(&st->spi->dev,
			 "Failed to get voltage reference value\n");
		goto disable_regulator_vref;
	}

	if (ret < 2000000 || ret > 3000000) {
		dev_warn(&st->spi->dev,
			 "Invalid external voltage ref. value %d uV\n", ret);
		ret = -EIO;
		goto disable_regulator_vref;
	}

	st->vref = ret / 1000;
	st->use_intref = false;

	return 0;

disable_regulator_vref:
	regulator_disable(st->vref_reg);
	st->vref_reg = NULL;
	return ret;
}

static int ad5761_probe(struct spi_device *spi)
{
	struct iio_dev *iio_dev;
	struct ad5761_state *st;
	int ret;
	const struct ad5761_chip_info *chip_info =
		&ad5761_chip_infos[spi_get_device_id(spi)->driver_data];
	enum ad5761_voltage_range voltage_range = AD5761_VOLTAGE_RANGE_0V_5V;
	struct ad5761_platform_data *pdata = dev_get_platdata(&spi->dev);

	iio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
	if (!iio_dev)
		return -ENOMEM;

	st = iio_priv(iio_dev);

	st->spi = spi;
	spi_set_drvdata(spi, iio_dev);

	ret = ad5761_get_vref(st, chip_info);
	if (ret)
		return ret;

	if (pdata)
		voltage_range = pdata->voltage_range;

	mutex_init(&st->lock);

	ret = ad5761_spi_set_range(st, voltage_range);
	if (ret)
		goto disable_regulator_err;

	iio_dev->info = &ad5761_info;
	iio_dev->modes = INDIO_DIRECT_MODE;
	iio_dev->channels = &chip_info->channel;
	iio_dev->num_channels = 1;
	iio_dev->name = spi_get_device_id(st->spi)->name;
	ret = iio_device_register(iio_dev);
	if (ret)
		goto disable_regulator_err;

	return 0;

disable_regulator_err:
	if (!IS_ERR_OR_NULL(st->vref_reg))
		regulator_disable(st->vref_reg);

	return ret;
}

static void ad5761_remove(struct spi_device *spi)
{
	struct iio_dev *iio_dev = spi_get_drvdata(spi);
	struct ad5761_state *st = iio_priv(iio_dev);

	iio_device_unregister(iio_dev);

	if (!IS_ERR_OR_NULL(st->vref_reg))
		regulator_disable(st->vref_reg);
}

static const struct spi_device_id ad5761_id[] = {
	{"ad5721", ID_AD5721},
	{"ad5721r", ID_AD5721R},
	{"ad5761", ID_AD5761},
	{"ad5761r", ID_AD5761R},
	{}
};
MODULE_DEVICE_TABLE(spi, ad5761_id);

static struct spi_driver ad5761_driver = {
	.driver = {
		   .name = "ad5761",
		   },
	.probe = ad5761_probe,
	.remove = ad5761_remove,
	.id_table = ad5761_id,
};
module_spi_driver(ad5761_driver);

MODULE_AUTHOR("Ricardo Ribalda <ribalda@kernel.org>");
MODULE_DESCRIPTION("Analog Devices AD5721, AD5721R, AD5761, AD5761R driver");
MODULE_LICENSE("GPL v2");