1// SPDX-License-Identifier: GPL-2.0
2/*
3 * AD8366 and similar Gain Amplifiers
4 * This driver supports the following gain amplifiers:
5 *   AD8366 Dual-Digital Variable Gain Amplifier (VGA)
6 *   ADA4961 BiCMOS RF Digital Gain Amplifier (DGA)
7 *   ADL5240 Digitally controlled variable gain amplifier (VGA)
8 *   HMC792A 0.25 dB LSB GaAs MMIC 6-Bit Digital Attenuator
9 *   HMC1119 0.25 dB LSB, 7-Bit, Silicon Digital Attenuator
10 *
11 * Copyright 2012-2019 Analog Devices Inc.
12 */
13
14#include <linux/device.h>
15#include <linux/kernel.h>
16#include <linux/slab.h>
17#include <linux/sysfs.h>
18#include <linux/spi/spi.h>
19#include <linux/regulator/consumer.h>
20#include <linux/gpio/consumer.h>
21#include <linux/err.h>
22#include <linux/module.h>
23#include <linux/bitrev.h>
24
25#include <linux/iio/iio.h>
26#include <linux/iio/sysfs.h>
27
28enum ad8366_type {
29	ID_AD8366,
30	ID_ADA4961,
31	ID_ADL5240,
32	ID_HMC792,
33	ID_HMC1119,
34};
35
36struct ad8366_info {
37	int gain_min;
38	int gain_max;
39};
40
41struct ad8366_state {
42	struct spi_device	*spi;
43	struct regulator	*reg;
44	struct mutex            lock; /* protect sensor state */
45	struct gpio_desc	*reset_gpio;
46	unsigned char		ch[2];
47	enum ad8366_type	type;
48	struct ad8366_info	*info;
49	/*
50	 * DMA (thus cache coherency maintenance) may require the
51	 * transfer buffers to live in their own cache lines.
52	 */
53	unsigned char		data[2] __aligned(IIO_DMA_MINALIGN);
54};
55
56static struct ad8366_info ad8366_infos[] = {
57	[ID_AD8366] = {
58		.gain_min = 4500,
59		.gain_max = 20500,
60	},
61	[ID_ADA4961] = {
62		.gain_min = -6000,
63		.gain_max = 15000,
64	},
65	[ID_ADL5240] = {
66		.gain_min = -11500,
67		.gain_max = 20000,
68	},
69	[ID_HMC792] = {
70		.gain_min = -15750,
71		.gain_max = 0,
72	},
73	[ID_HMC1119] = {
74		.gain_min = -31750,
75		.gain_max = 0,
76	},
77};
78
79static int ad8366_write(struct iio_dev *indio_dev,
80			unsigned char ch_a, unsigned char ch_b)
81{
82	struct ad8366_state *st = iio_priv(indio_dev);
83	int ret;
84
85	switch (st->type) {
86	case ID_AD8366:
87		ch_a = bitrev8(ch_a & 0x3F);
88		ch_b = bitrev8(ch_b & 0x3F);
89
90		st->data[0] = ch_b >> 4;
91		st->data[1] = (ch_b << 4) | (ch_a >> 2);
92		break;
93	case ID_ADA4961:
94		st->data[0] = ch_a & 0x1F;
95		break;
96	case ID_ADL5240:
97		st->data[0] = (ch_a & 0x3F);
98		break;
99	case ID_HMC792:
100	case ID_HMC1119:
101		st->data[0] = ch_a;
102		break;
103	}
104
105	ret = spi_write(st->spi, st->data, indio_dev->num_channels);
106	if (ret < 0)
107		dev_err(&indio_dev->dev, "write failed (%d)", ret);
108
109	return ret;
110}
111
112static int ad8366_read_raw(struct iio_dev *indio_dev,
113			   struct iio_chan_spec const *chan,
114			   int *val,
115			   int *val2,
116			   long m)
117{
118	struct ad8366_state *st = iio_priv(indio_dev);
119	int ret;
120	int code, gain = 0;
121
122	mutex_lock(&st->lock);
123	switch (m) {
124	case IIO_CHAN_INFO_HARDWAREGAIN:
125		code = st->ch[chan->channel];
126
127		switch (st->type) {
128		case ID_AD8366:
129			gain = code * 253 + 4500;
130			break;
131		case ID_ADA4961:
132			gain = 15000 - code * 1000;
133			break;
134		case ID_ADL5240:
135			gain = 20000 - 31500 + code * 500;
136			break;
137		case ID_HMC792:
138			gain = -1 * code * 500;
139			break;
140		case ID_HMC1119:
141			gain = -1 * code * 250;
142			break;
143		}
144
145		/* Values in dB */
146		*val = gain / 1000;
147		*val2 = (gain % 1000) * 1000;
148
149		ret = IIO_VAL_INT_PLUS_MICRO_DB;
150		break;
151	default:
152		ret = -EINVAL;
153	}
154	mutex_unlock(&st->lock);
155
156	return ret;
157};
158
159static int ad8366_write_raw(struct iio_dev *indio_dev,
160			    struct iio_chan_spec const *chan,
161			    int val,
162			    int val2,
163			    long mask)
164{
165	struct ad8366_state *st = iio_priv(indio_dev);
166	struct ad8366_info *inf = st->info;
167	int code = 0, gain;
168	int ret;
169
170	/* Values in dB */
171	if (val < 0)
172		gain = (val * 1000) - (val2 / 1000);
173	else
174		gain = (val * 1000) + (val2 / 1000);
175
176	if (gain > inf->gain_max || gain < inf->gain_min)
177		return -EINVAL;
178
179	switch (st->type) {
180	case ID_AD8366:
181		code = (gain - 4500) / 253;
182		break;
183	case ID_ADA4961:
184		code = (15000 - gain) / 1000;
185		break;
186	case ID_ADL5240:
187		code = ((gain - 500 - 20000) / 500) & 0x3F;
188		break;
189	case ID_HMC792:
190		code = (abs(gain) / 500) & 0x3F;
191		break;
192	case ID_HMC1119:
193		code = (abs(gain) / 250) & 0x7F;
194		break;
195	}
196
197	mutex_lock(&st->lock);
198	switch (mask) {
199	case IIO_CHAN_INFO_HARDWAREGAIN:
200		st->ch[chan->channel] = code;
201		ret = ad8366_write(indio_dev, st->ch[0], st->ch[1]);
202		break;
203	default:
204		ret = -EINVAL;
205	}
206	mutex_unlock(&st->lock);
207
208	return ret;
209}
210
211static int ad8366_write_raw_get_fmt(struct iio_dev *indio_dev,
212				    struct iio_chan_spec const *chan,
213				    long mask)
214{
215	switch (mask) {
216	case IIO_CHAN_INFO_HARDWAREGAIN:
217		return IIO_VAL_INT_PLUS_MICRO_DB;
218	default:
219		return -EINVAL;
220	}
221}
222
223static const struct iio_info ad8366_info = {
224	.read_raw = &ad8366_read_raw,
225	.write_raw = &ad8366_write_raw,
226	.write_raw_get_fmt = &ad8366_write_raw_get_fmt,
227};
228
229#define AD8366_CHAN(_channel) {				\
230	.type = IIO_VOLTAGE,				\
231	.output = 1,					\
232	.indexed = 1,					\
233	.channel = _channel,				\
234	.info_mask_separate = BIT(IIO_CHAN_INFO_HARDWAREGAIN),\
235}
236
237static const struct iio_chan_spec ad8366_channels[] = {
238	AD8366_CHAN(0),
239	AD8366_CHAN(1),
240};
241
242static const struct iio_chan_spec ada4961_channels[] = {
243	AD8366_CHAN(0),
244};
245
246static int ad8366_probe(struct spi_device *spi)
247{
248	struct iio_dev *indio_dev;
249	struct ad8366_state *st;
250	int ret;
251
252	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
253	if (indio_dev == NULL)
254		return -ENOMEM;
255
256	st = iio_priv(indio_dev);
257
258	st->reg = devm_regulator_get(&spi->dev, "vcc");
259	if (!IS_ERR(st->reg)) {
260		ret = regulator_enable(st->reg);
261		if (ret)
262			return ret;
263	}
264
265	spi_set_drvdata(spi, indio_dev);
266	mutex_init(&st->lock);
267	st->spi = spi;
268	st->type = spi_get_device_id(spi)->driver_data;
269
270	switch (st->type) {
271	case ID_AD8366:
272		indio_dev->channels = ad8366_channels;
273		indio_dev->num_channels = ARRAY_SIZE(ad8366_channels);
274		break;
275	case ID_ADA4961:
276	case ID_ADL5240:
277	case ID_HMC792:
278	case ID_HMC1119:
279		st->reset_gpio = devm_gpiod_get_optional(&spi->dev, "reset", GPIOD_OUT_HIGH);
280		if (IS_ERR(st->reset_gpio)) {
281			ret = PTR_ERR(st->reset_gpio);
282			goto error_disable_reg;
283		}
284		indio_dev->channels = ada4961_channels;
285		indio_dev->num_channels = ARRAY_SIZE(ada4961_channels);
286		break;
287	default:
288		dev_err(&spi->dev, "Invalid device ID\n");
289		ret = -EINVAL;
290		goto error_disable_reg;
291	}
292
293	st->info = &ad8366_infos[st->type];
294	indio_dev->name = spi_get_device_id(spi)->name;
295	indio_dev->info = &ad8366_info;
296	indio_dev->modes = INDIO_DIRECT_MODE;
297
298	ret = ad8366_write(indio_dev, 0, 0);
299	if (ret < 0)
300		goto error_disable_reg;
301
302	ret = iio_device_register(indio_dev);
303	if (ret)
304		goto error_disable_reg;
305
306	return 0;
307
308error_disable_reg:
309	if (!IS_ERR(st->reg))
310		regulator_disable(st->reg);
311
312	return ret;
313}
314
315static void ad8366_remove(struct spi_device *spi)
316{
317	struct iio_dev *indio_dev = spi_get_drvdata(spi);
318	struct ad8366_state *st = iio_priv(indio_dev);
319	struct regulator *reg = st->reg;
320
321	iio_device_unregister(indio_dev);
322
323	if (!IS_ERR(reg))
324		regulator_disable(reg);
325}
326
327static const struct spi_device_id ad8366_id[] = {
328	{"ad8366",  ID_AD8366},
329	{"ada4961", ID_ADA4961},
330	{"adl5240", ID_ADL5240},
331	{"hmc792a", ID_HMC792},
332	{"hmc1119", ID_HMC1119},
333	{}
334};
335MODULE_DEVICE_TABLE(spi, ad8366_id);
336
337static struct spi_driver ad8366_driver = {
338	.driver = {
339		.name	= KBUILD_MODNAME,
340	},
341	.probe		= ad8366_probe,
342	.remove		= ad8366_remove,
343	.id_table	= ad8366_id,
344};
345
346module_spi_driver(ad8366_driver);
347
348MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
349MODULE_DESCRIPTION("Analog Devices AD8366 and similar Gain Amplifiers");
350MODULE_LICENSE("GPL v2");
351