summaryrefslogtreecommitdiffstats
path: root/drivers/iio/amplifiers/ad8366.c
blob: 31564afb13a2028f018926663387b47bfc967199 (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
// SPDX-License-Identifier: GPL-2.0
/*
 * AD8366 and similar Gain Amplifiers
 * This driver supports the following gain amplifiers:
 *   AD8366 Dual-Digital Variable Gain Amplifier (VGA)
 *   ADA4961 BiCMOS RF Digital Gain Amplifier (DGA)
 *   ADL5240 Digitally controlled variable gain amplifier (VGA)
 *   HMC792A 0.25 dB LSB GaAs MMIC 6-Bit Digital Attenuator
 *   HMC1119 0.25 dB LSB, 7-Bit, Silicon Digital Attenuator
 *
 * Copyright 2012-2019 Analog Devices Inc.
 */

#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/spi/spi.h>
#include <linux/regulator/consumer.h>
#include <linux/gpio/consumer.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/bitrev.h>

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

enum ad8366_type {
	ID_AD8366,
	ID_ADA4961,
	ID_ADL5240,
	ID_HMC792,
	ID_HMC1119,
};

struct ad8366_info {
	int gain_min;
	int gain_max;
};

struct ad8366_state {
	struct spi_device	*spi;
	struct regulator	*reg;
	struct mutex            lock; /* protect sensor state */
	struct gpio_desc	*reset_gpio;
	unsigned char		ch[2];
	enum ad8366_type	type;
	struct ad8366_info	*info;
	/*
	 * DMA (thus cache coherency maintenance) may require the
	 * transfer buffers to live in their own cache lines.
	 */
	unsigned char		data[2] __aligned(IIO_DMA_MINALIGN);
};

static struct ad8366_info ad8366_infos[] = {
	[ID_AD8366] = {
		.gain_min = 4500,
		.gain_max = 20500,
	},
	[ID_ADA4961] = {
		.gain_min = -6000,
		.gain_max = 15000,
	},
	[ID_ADL5240] = {
		.gain_min = -11500,
		.gain_max = 20000,
	},
	[ID_HMC792] = {
		.gain_min = -15750,
		.gain_max = 0,
	},
	[ID_HMC1119] = {
		.gain_min = -31750,
		.gain_max = 0,
	},
};

static int ad8366_write(struct iio_dev *indio_dev,
			unsigned char ch_a, unsigned char ch_b)
{
	struct ad8366_state *st = iio_priv(indio_dev);
	int ret;

	switch (st->type) {
	case ID_AD8366:
		ch_a = bitrev8(ch_a & 0x3F);
		ch_b = bitrev8(ch_b & 0x3F);

		st->data[0] = ch_b >> 4;
		st->data[1] = (ch_b << 4) | (ch_a >> 2);
		break;
	case ID_ADA4961:
		st->data[0] = ch_a & 0x1F;
		break;
	case ID_ADL5240:
		st->data[0] = (ch_a & 0x3F);
		break;
	case ID_HMC792:
	case ID_HMC1119:
		st->data[0] = ch_a;
		break;
	}

	ret = spi_write(st->spi, st->data, indio_dev->num_channels);
	if (ret < 0)
		dev_err(&indio_dev->dev, "write failed (%d)", ret);

	return ret;
}

static int ad8366_read_raw(struct iio_dev *indio_dev,
			   struct iio_chan_spec const *chan,
			   int *val,
			   int *val2,
			   long m)
{
	struct ad8366_state *st = iio_priv(indio_dev);
	int ret;
	int code, gain = 0;

	mutex_lock(&st->lock);
	switch (m) {
	case IIO_CHAN_INFO_HARDWAREGAIN:
		code = st->ch[chan->channel];

		switch (st->type) {
		case ID_AD8366:
			gain = code * 253 + 4500;
			break;
		case ID_ADA4961:
			gain = 15000 - code * 1000;
			break;
		case ID_ADL5240:
			gain = 20000 - 31500 + code * 500;
			break;
		case ID_HMC792:
			gain = -1 * code * 500;
			break;
		case ID_HMC1119:
			gain = -1 * code * 250;
			break;
		}

		/* Values in dB */
		*val = gain / 1000;
		*val2 = (gain % 1000) * 1000;

		ret = IIO_VAL_INT_PLUS_MICRO_DB;
		break;
	default:
		ret = -EINVAL;
	}
	mutex_unlock(&st->lock);

	return ret;
};

static int ad8366_write_raw(struct iio_dev *indio_dev,
			    struct iio_chan_spec const *chan,
			    int val,
			    int val2,
			    long mask)
{
	struct ad8366_state *st = iio_priv(indio_dev);
	struct ad8366_info *inf = st->info;
	int code = 0, gain;
	int ret;

	/* Values in dB */
	if (val < 0)
		gain = (val * 1000) - (val2 / 1000);
	else
		gain = (val * 1000) + (val2 / 1000);

	if (gain > inf->gain_max || gain < inf->gain_min)
		return -EINVAL;

	switch (st->type) {
	case ID_AD8366:
		code = (gain - 4500) / 253;
		break;
	case ID_ADA4961:
		code = (15000 - gain) / 1000;
		break;
	case ID_ADL5240:
		code = ((gain - 500 - 20000) / 500) & 0x3F;
		break;
	case ID_HMC792:
		code = (abs(gain) / 500) & 0x3F;
		break;
	case ID_HMC1119:
		code = (abs(gain) / 250) & 0x7F;
		break;
	}

	mutex_lock(&st->lock);
	switch (mask) {
	case IIO_CHAN_INFO_HARDWAREGAIN:
		st->ch[chan->channel] = code;
		ret = ad8366_write(indio_dev, st->ch[0], st->ch[1]);
		break;
	default:
		ret = -EINVAL;
	}
	mutex_unlock(&st->lock);

	return ret;
}

static int ad8366_write_raw_get_fmt(struct iio_dev *indio_dev,
				    struct iio_chan_spec const *chan,
				    long mask)
{
	switch (mask) {
	case IIO_CHAN_INFO_HARDWAREGAIN:
		return IIO_VAL_INT_PLUS_MICRO_DB;
	default:
		return -EINVAL;
	}
}

static const struct iio_info ad8366_info = {
	.read_raw = &ad8366_read_raw,
	.write_raw = &ad8366_write_raw,
	.write_raw_get_fmt = &ad8366_write_raw_get_fmt,
};

#define AD8366_CHAN(_channel) {				\
	.type = IIO_VOLTAGE,				\
	.output = 1,					\
	.indexed = 1,					\
	.channel = _channel,				\
	.info_mask_separate = BIT(IIO_CHAN_INFO_HARDWAREGAIN),\
}

static const struct iio_chan_spec ad8366_channels[] = {
	AD8366_CHAN(0),
	AD8366_CHAN(1),
};

static const struct iio_chan_spec ada4961_channels[] = {
	AD8366_CHAN(0),
};

static int ad8366_probe(struct spi_device *spi)
{
	struct iio_dev *indio_dev;
	struct ad8366_state *st;
	int ret;

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

	st = iio_priv(indio_dev);

	st->reg = devm_regulator_get(&spi->dev, "vcc");
	if (!IS_ERR(st->reg)) {
		ret = regulator_enable(st->reg);
		if (ret)
			return ret;
	}

	spi_set_drvdata(spi, indio_dev);
	mutex_init(&st->lock);
	st->spi = spi;
	st->type = spi_get_device_id(spi)->driver_data;

	switch (st->type) {
	case ID_AD8366:
		indio_dev->channels = ad8366_channels;
		indio_dev->num_channels = ARRAY_SIZE(ad8366_channels);
		break;
	case ID_ADA4961:
	case ID_ADL5240:
	case ID_HMC792:
	case ID_HMC1119:
		st->reset_gpio = devm_gpiod_get_optional(&spi->dev, "reset", GPIOD_OUT_HIGH);
		if (IS_ERR(st->reset_gpio)) {
			ret = PTR_ERR(st->reset_gpio);
			goto error_disable_reg;
		}
		indio_dev->channels = ada4961_channels;
		indio_dev->num_channels = ARRAY_SIZE(ada4961_channels);
		break;
	default:
		dev_err(&spi->dev, "Invalid device ID\n");
		ret = -EINVAL;
		goto error_disable_reg;
	}

	st->info = &ad8366_infos[st->type];
	indio_dev->name = spi_get_device_id(spi)->name;
	indio_dev->info = &ad8366_info;
	indio_dev->modes = INDIO_DIRECT_MODE;

	ret = ad8366_write(indio_dev, 0, 0);
	if (ret < 0)
		goto error_disable_reg;

	ret = iio_device_register(indio_dev);
	if (ret)
		goto error_disable_reg;

	return 0;

error_disable_reg:
	if (!IS_ERR(st->reg))
		regulator_disable(st->reg);

	return ret;
}

static void ad8366_remove(struct spi_device *spi)
{
	struct iio_dev *indio_dev = spi_get_drvdata(spi);
	struct ad8366_state *st = iio_priv(indio_dev);
	struct regulator *reg = st->reg;

	iio_device_unregister(indio_dev);

	if (!IS_ERR(reg))
		regulator_disable(reg);
}

static const struct spi_device_id ad8366_id[] = {
	{"ad8366",  ID_AD8366},
	{"ada4961", ID_ADA4961},
	{"adl5240", ID_ADL5240},
	{"hmc792a", ID_HMC792},
	{"hmc1119", ID_HMC1119},
	{}
};
MODULE_DEVICE_TABLE(spi, ad8366_id);

static struct spi_driver ad8366_driver = {
	.driver = {
		.name	= KBUILD_MODNAME,
	},
	.probe		= ad8366_probe,
	.remove		= ad8366_remove,
	.id_table	= ad8366_id,
};

module_spi_driver(ad8366_driver);

MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
MODULE_DESCRIPTION("Analog Devices AD8366 and similar Gain Amplifiers");
MODULE_LICENSE("GPL v2");