1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * AD7787/AD7788/AD7789/AD7790/AD7791 SPI ADC driver
4 *
5 * Copyright 2012 Analog Devices Inc.
6 * Author: Lars-Peter Clausen <lars@metafoo.de>
7 */
8
9 #include <linux/interrupt.h>
10 #include <linux/device.h>
11 #include <linux/kernel.h>
12 #include <linux/slab.h>
13 #include <linux/sysfs.h>
14 #include <linux/spi/spi.h>
15 #include <linux/regulator/consumer.h>
16 #include <linux/err.h>
17 #include <linux/sched.h>
18 #include <linux/delay.h>
19 #include <linux/module.h>
20
21 #include <linux/iio/iio.h>
22 #include <linux/iio/sysfs.h>
23 #include <linux/iio/buffer.h>
24 #include <linux/iio/trigger.h>
25 #include <linux/iio/trigger_consumer.h>
26 #include <linux/iio/triggered_buffer.h>
27 #include <linux/iio/adc/ad_sigma_delta.h>
28
29 #include <linux/platform_data/ad7791.h>
30
31 #define AD7791_REG_COMM 0x0 /* For writes */
32 #define AD7791_REG_STATUS 0x0 /* For reads */
33 #define AD7791_REG_MODE 0x1
34 #define AD7791_REG_FILTER 0x2
35 #define AD7791_REG_DATA 0x3
36
37 #define AD7791_MODE_CONTINUOUS 0x00
38 #define AD7791_MODE_SINGLE 0x02
39 #define AD7791_MODE_POWERDOWN 0x03
40
41 #define AD7791_CH_AIN1P_AIN1N 0x00
42 #define AD7791_CH_AIN2 0x01
43 #define AD7791_CH_AIN1N_AIN1N 0x02
44 #define AD7791_CH_AVDD_MONITOR 0x03
45
46 #define AD7791_FILTER_CLK_DIV_1 (0x0 << 4)
47 #define AD7791_FILTER_CLK_DIV_2 (0x1 << 4)
48 #define AD7791_FILTER_CLK_DIV_4 (0x2 << 4)
49 #define AD7791_FILTER_CLK_DIV_8 (0x3 << 4)
50 #define AD7791_FILTER_CLK_MASK (0x3 << 4)
51 #define AD7791_FILTER_RATE_120 0x0
52 #define AD7791_FILTER_RATE_100 0x1
53 #define AD7791_FILTER_RATE_33_3 0x2
54 #define AD7791_FILTER_RATE_20 0x3
55 #define AD7791_FILTER_RATE_16_6 0x4
56 #define AD7791_FILTER_RATE_16_7 0x5
57 #define AD7791_FILTER_RATE_13_3 0x6
58 #define AD7791_FILTER_RATE_9_5 0x7
59 #define AD7791_FILTER_RATE_MASK 0x7
60
61 #define AD7791_MODE_BUFFER BIT(1)
62 #define AD7791_MODE_UNIPOLAR BIT(2)
63 #define AD7791_MODE_BURNOUT BIT(3)
64 #define AD7791_MODE_SEL_MASK (0x3 << 6)
65 #define AD7791_MODE_SEL(x) ((x) << 6)
66
67 #define __AD7991_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
68 _storagebits, _shift, _extend_name, _type, _mask_all) \
69 { \
70 .type = (_type), \
71 .differential = (_channel2 == -1 ? 0 : 1), \
72 .indexed = 1, \
73 .channel = (_channel1), \
74 .channel2 = (_channel2), \
75 .address = (_address), \
76 .extend_name = (_extend_name), \
77 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
78 BIT(IIO_CHAN_INFO_OFFSET), \
79 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
80 .info_mask_shared_by_all = _mask_all, \
81 .scan_index = (_si), \
82 .scan_type = { \
83 .sign = 'u', \
84 .realbits = (_bits), \
85 .storagebits = (_storagebits), \
86 .shift = (_shift), \
87 .endianness = IIO_BE, \
88 }, \
89 }
90
91 #define AD7991_SHORTED_CHANNEL(_si, _channel, _address, _bits, \
92 _storagebits, _shift) \
93 __AD7991_CHANNEL(_si, _channel, _channel, _address, _bits, \
94 _storagebits, _shift, "shorted", IIO_VOLTAGE, \
95 BIT(IIO_CHAN_INFO_SAMP_FREQ))
96
97 #define AD7991_CHANNEL(_si, _channel, _address, _bits, \
98 _storagebits, _shift) \
99 __AD7991_CHANNEL(_si, _channel, -1, _address, _bits, \
100 _storagebits, _shift, NULL, IIO_VOLTAGE, \
101 BIT(IIO_CHAN_INFO_SAMP_FREQ))
102
103 #define AD7991_DIFF_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
104 _storagebits, _shift) \
105 __AD7991_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
106 _storagebits, _shift, NULL, IIO_VOLTAGE, \
107 BIT(IIO_CHAN_INFO_SAMP_FREQ))
108
109 #define AD7991_SUPPLY_CHANNEL(_si, _channel, _address, _bits, _storagebits, \
110 _shift) \
111 __AD7991_CHANNEL(_si, _channel, -1, _address, _bits, \
112 _storagebits, _shift, "supply", IIO_VOLTAGE, \
113 BIT(IIO_CHAN_INFO_SAMP_FREQ))
114
115 #define DECLARE_AD7787_CHANNELS(name, bits, storagebits) \
116 const struct iio_chan_spec name[] = { \
117 AD7991_DIFF_CHANNEL(0, 0, 0, AD7791_CH_AIN1P_AIN1N, \
118 (bits), (storagebits), 0), \
119 AD7991_CHANNEL(1, 1, AD7791_CH_AIN2, (bits), (storagebits), 0), \
120 AD7991_SHORTED_CHANNEL(2, 0, AD7791_CH_AIN1N_AIN1N, \
121 (bits), (storagebits), 0), \
122 AD7991_SUPPLY_CHANNEL(3, 2, AD7791_CH_AVDD_MONITOR, \
123 (bits), (storagebits), 0), \
124 IIO_CHAN_SOFT_TIMESTAMP(4), \
125 }
126
127 #define DECLARE_AD7791_CHANNELS(name, bits, storagebits) \
128 const struct iio_chan_spec name[] = { \
129 AD7991_DIFF_CHANNEL(0, 0, 0, AD7791_CH_AIN1P_AIN1N, \
130 (bits), (storagebits), 0), \
131 AD7991_SHORTED_CHANNEL(1, 0, AD7791_CH_AIN1N_AIN1N, \
132 (bits), (storagebits), 0), \
133 AD7991_SUPPLY_CHANNEL(2, 1, AD7791_CH_AVDD_MONITOR, \
134 (bits), (storagebits), 0), \
135 IIO_CHAN_SOFT_TIMESTAMP(3), \
136 }
137
138 static DECLARE_AD7787_CHANNELS(ad7787_channels, 24, 32);
139 static DECLARE_AD7791_CHANNELS(ad7790_channels, 16, 16);
140 static DECLARE_AD7791_CHANNELS(ad7791_channels, 24, 32);
141
142 enum {
143 AD7787,
144 AD7788,
145 AD7789,
146 AD7790,
147 AD7791,
148 };
149
150 enum ad7791_chip_info_flags {
151 AD7791_FLAG_HAS_FILTER = (1 << 0),
152 AD7791_FLAG_HAS_BUFFER = (1 << 1),
153 AD7791_FLAG_HAS_UNIPOLAR = (1 << 2),
154 AD7791_FLAG_HAS_BURNOUT = (1 << 3),
155 };
156
157 struct ad7791_chip_info {
158 const struct iio_chan_spec *channels;
159 unsigned int num_channels;
160 enum ad7791_chip_info_flags flags;
161 };
162
163 static const struct ad7791_chip_info ad7791_chip_infos[] = {
164 [AD7787] = {
165 .channels = ad7787_channels,
166 .num_channels = ARRAY_SIZE(ad7787_channels),
167 .flags = AD7791_FLAG_HAS_FILTER | AD7791_FLAG_HAS_BUFFER |
168 AD7791_FLAG_HAS_UNIPOLAR | AD7791_FLAG_HAS_BURNOUT,
169 },
170 [AD7788] = {
171 .channels = ad7790_channels,
172 .num_channels = ARRAY_SIZE(ad7790_channels),
173 .flags = AD7791_FLAG_HAS_UNIPOLAR,
174 },
175 [AD7789] = {
176 .channels = ad7791_channels,
177 .num_channels = ARRAY_SIZE(ad7791_channels),
178 .flags = AD7791_FLAG_HAS_UNIPOLAR,
179 },
180 [AD7790] = {
181 .channels = ad7790_channels,
182 .num_channels = ARRAY_SIZE(ad7790_channels),
183 .flags = AD7791_FLAG_HAS_FILTER | AD7791_FLAG_HAS_BUFFER |
184 AD7791_FLAG_HAS_BURNOUT,
185 },
186 [AD7791] = {
187 .channels = ad7791_channels,
188 .num_channels = ARRAY_SIZE(ad7791_channels),
189 .flags = AD7791_FLAG_HAS_FILTER | AD7791_FLAG_HAS_BUFFER |
190 AD7791_FLAG_HAS_UNIPOLAR | AD7791_FLAG_HAS_BURNOUT,
191 },
192 };
193
194 struct ad7791_state {
195 struct ad_sigma_delta sd;
196 uint8_t mode;
197 uint8_t filter;
198
199 struct regulator *reg;
200 const struct ad7791_chip_info *info;
201 };
202
203 static const int ad7791_sample_freq_avail[8][2] = {
204 [AD7791_FILTER_RATE_120] = { 120, 0 },
205 [AD7791_FILTER_RATE_100] = { 100, 0 },
206 [AD7791_FILTER_RATE_33_3] = { 33, 300000 },
207 [AD7791_FILTER_RATE_20] = { 20, 0 },
208 [AD7791_FILTER_RATE_16_6] = { 16, 600000 },
209 [AD7791_FILTER_RATE_16_7] = { 16, 700000 },
210 [AD7791_FILTER_RATE_13_3] = { 13, 300000 },
211 [AD7791_FILTER_RATE_9_5] = { 9, 500000 },
212 };
213
ad_sigma_delta_to_ad7791(struct ad_sigma_delta * sd)214 static struct ad7791_state *ad_sigma_delta_to_ad7791(struct ad_sigma_delta *sd)
215 {
216 return container_of(sd, struct ad7791_state, sd);
217 }
218
ad7791_set_channel(struct ad_sigma_delta * sd,unsigned int channel)219 static int ad7791_set_channel(struct ad_sigma_delta *sd, unsigned int channel)
220 {
221 ad_sd_set_comm(sd, channel);
222
223 return 0;
224 }
225
ad7791_set_mode(struct ad_sigma_delta * sd,enum ad_sigma_delta_mode mode)226 static int ad7791_set_mode(struct ad_sigma_delta *sd,
227 enum ad_sigma_delta_mode mode)
228 {
229 struct ad7791_state *st = ad_sigma_delta_to_ad7791(sd);
230
231 switch (mode) {
232 case AD_SD_MODE_CONTINUOUS:
233 mode = AD7791_MODE_CONTINUOUS;
234 break;
235 case AD_SD_MODE_SINGLE:
236 mode = AD7791_MODE_SINGLE;
237 break;
238 case AD_SD_MODE_IDLE:
239 case AD_SD_MODE_POWERDOWN:
240 mode = AD7791_MODE_POWERDOWN;
241 break;
242 }
243
244 st->mode &= ~AD7791_MODE_SEL_MASK;
245 st->mode |= AD7791_MODE_SEL(mode);
246
247 return ad_sd_write_reg(sd, AD7791_REG_MODE, sizeof(st->mode), st->mode);
248 }
249
250 static const struct ad_sigma_delta_info ad7791_sigma_delta_info = {
251 .set_channel = ad7791_set_channel,
252 .set_mode = ad7791_set_mode,
253 .has_registers = true,
254 .addr_shift = 4,
255 .read_mask = BIT(3),
256 .irq_flags = IRQF_TRIGGER_FALLING,
257 .num_resetclks = 32,
258 };
259
ad7791_read_raw(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,int * val,int * val2,long info)260 static int ad7791_read_raw(struct iio_dev *indio_dev,
261 const struct iio_chan_spec *chan, int *val, int *val2, long info)
262 {
263 struct ad7791_state *st = iio_priv(indio_dev);
264 bool unipolar = !!(st->mode & AD7791_MODE_UNIPOLAR);
265 unsigned int rate;
266
267 switch (info) {
268 case IIO_CHAN_INFO_RAW:
269 return ad_sigma_delta_single_conversion(indio_dev, chan, val);
270 case IIO_CHAN_INFO_OFFSET:
271 /**
272 * Unipolar: 0 to VREF
273 * Bipolar -VREF to VREF
274 **/
275 if (unipolar)
276 *val = 0;
277 else
278 *val = -(1 << (chan->scan_type.realbits - 1));
279 return IIO_VAL_INT;
280 case IIO_CHAN_INFO_SCALE:
281 /* The monitor channel uses an internal reference. */
282 if (chan->address == AD7791_CH_AVDD_MONITOR) {
283 /*
284 * The signal is attenuated by a factor of 5 and
285 * compared against a 1.17V internal reference.
286 */
287 *val = 1170 * 5;
288 } else {
289 int voltage_uv;
290
291 voltage_uv = regulator_get_voltage(st->reg);
292 if (voltage_uv < 0)
293 return voltage_uv;
294
295 *val = voltage_uv / 1000;
296 }
297 if (unipolar)
298 *val2 = chan->scan_type.realbits;
299 else
300 *val2 = chan->scan_type.realbits - 1;
301
302 return IIO_VAL_FRACTIONAL_LOG2;
303 case IIO_CHAN_INFO_SAMP_FREQ:
304 rate = st->filter & AD7791_FILTER_RATE_MASK;
305 *val = ad7791_sample_freq_avail[rate][0];
306 *val2 = ad7791_sample_freq_avail[rate][1];
307 return IIO_VAL_INT_PLUS_MICRO;
308 }
309
310 return -EINVAL;
311 }
312
__ad7791_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)313 static int __ad7791_write_raw(struct iio_dev *indio_dev,
314 struct iio_chan_spec const *chan, int val, int val2, long mask)
315 {
316 struct ad7791_state *st = iio_priv(indio_dev);
317 int i;
318
319 switch (mask) {
320 case IIO_CHAN_INFO_SAMP_FREQ:
321 for (i = 0; i < ARRAY_SIZE(ad7791_sample_freq_avail); i++) {
322 if (ad7791_sample_freq_avail[i][0] == val &&
323 ad7791_sample_freq_avail[i][1] == val2)
324 break;
325 }
326
327 if (i == ARRAY_SIZE(ad7791_sample_freq_avail))
328 return -EINVAL;
329
330 st->filter &= ~AD7791_FILTER_RATE_MASK;
331 st->filter |= i;
332 ad_sd_write_reg(&st->sd, AD7791_REG_FILTER,
333 sizeof(st->filter),
334 st->filter);
335 return 0;
336 default:
337 return -EINVAL;
338 }
339 }
340
ad7791_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)341 static int ad7791_write_raw(struct iio_dev *indio_dev,
342 struct iio_chan_spec const *chan, int val, int val2, long mask)
343 {
344 int ret;
345
346 if (!iio_device_claim_direct(indio_dev))
347 return -EBUSY;
348
349 ret = __ad7791_write_raw(indio_dev, chan, val, val2, mask);
350
351 iio_device_release_direct(indio_dev);
352 return ret;
353 }
354
355 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("120 100 33.3 20 16.7 16.6 13.3 9.5");
356
357 static struct attribute *ad7791_attributes[] = {
358 &iio_const_attr_sampling_frequency_available.dev_attr.attr,
359 NULL
360 };
361
362 static const struct attribute_group ad7791_attribute_group = {
363 .attrs = ad7791_attributes,
364 };
365
366 static const struct iio_info ad7791_info = {
367 .read_raw = &ad7791_read_raw,
368 .write_raw = &ad7791_write_raw,
369 .attrs = &ad7791_attribute_group,
370 .validate_trigger = ad_sd_validate_trigger,
371 };
372
373 static const struct iio_info ad7791_no_filter_info = {
374 .read_raw = &ad7791_read_raw,
375 .write_raw = &ad7791_write_raw,
376 .validate_trigger = ad_sd_validate_trigger,
377 };
378
ad7791_setup(struct ad7791_state * st,const struct ad7791_platform_data * pdata)379 static int ad7791_setup(struct ad7791_state *st,
380 const struct ad7791_platform_data *pdata)
381 {
382 /* Set to poweron-reset default values */
383 st->mode = AD7791_MODE_BUFFER;
384 st->filter = AD7791_FILTER_RATE_16_6;
385
386 if (!pdata)
387 return 0;
388
389 if ((st->info->flags & AD7791_FLAG_HAS_BUFFER) && !pdata->buffered)
390 st->mode &= ~AD7791_MODE_BUFFER;
391
392 if ((st->info->flags & AD7791_FLAG_HAS_BURNOUT) &&
393 pdata->burnout_current)
394 st->mode |= AD7791_MODE_BURNOUT;
395
396 if ((st->info->flags & AD7791_FLAG_HAS_UNIPOLAR) && pdata->unipolar)
397 st->mode |= AD7791_MODE_UNIPOLAR;
398
399 return ad_sd_write_reg(&st->sd, AD7791_REG_MODE, sizeof(st->mode),
400 st->mode);
401 }
402
ad7791_reg_disable(void * reg)403 static void ad7791_reg_disable(void *reg)
404 {
405 regulator_disable(reg);
406 }
407
ad7791_probe(struct spi_device * spi)408 static int ad7791_probe(struct spi_device *spi)
409 {
410 const struct ad7791_platform_data *pdata = dev_get_platdata(&spi->dev);
411 struct iio_dev *indio_dev;
412 struct ad7791_state *st;
413 int ret;
414
415 if (!spi->irq) {
416 dev_err(&spi->dev, "Missing IRQ.\n");
417 return -ENXIO;
418 }
419
420 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
421 if (!indio_dev)
422 return -ENOMEM;
423
424 st = iio_priv(indio_dev);
425
426 st->reg = devm_regulator_get(&spi->dev, "refin");
427 if (IS_ERR(st->reg))
428 return PTR_ERR(st->reg);
429
430 ret = regulator_enable(st->reg);
431 if (ret)
432 return ret;
433
434 ret = devm_add_action_or_reset(&spi->dev, ad7791_reg_disable, st->reg);
435 if (ret)
436 return ret;
437
438 st->info = &ad7791_chip_infos[spi_get_device_id(spi)->driver_data];
439 ad_sd_init(&st->sd, indio_dev, spi, &ad7791_sigma_delta_info);
440
441 indio_dev->name = spi_get_device_id(spi)->name;
442 indio_dev->modes = INDIO_DIRECT_MODE;
443 indio_dev->channels = st->info->channels;
444 indio_dev->num_channels = st->info->num_channels;
445 if (st->info->flags & AD7791_FLAG_HAS_FILTER)
446 indio_dev->info = &ad7791_info;
447 else
448 indio_dev->info = &ad7791_no_filter_info;
449
450 ret = devm_ad_sd_setup_buffer_and_trigger(&spi->dev, indio_dev);
451 if (ret)
452 return ret;
453
454 ret = ad7791_setup(st, pdata);
455 if (ret)
456 return ret;
457
458 return devm_iio_device_register(&spi->dev, indio_dev);
459 }
460
461 static const struct spi_device_id ad7791_spi_ids[] = {
462 { "ad7787", AD7787 },
463 { "ad7788", AD7788 },
464 { "ad7789", AD7789 },
465 { "ad7790", AD7790 },
466 { "ad7791", AD7791 },
467 { }
468 };
469 MODULE_DEVICE_TABLE(spi, ad7791_spi_ids);
470
471 static struct spi_driver ad7791_driver = {
472 .driver = {
473 .name = "ad7791",
474 },
475 .probe = ad7791_probe,
476 .id_table = ad7791_spi_ids,
477 };
478 module_spi_driver(ad7791_driver);
479
480 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
481 MODULE_DESCRIPTION("Analog Devices AD7787/AD7788/AD7789/AD7790/AD7791 ADC driver");
482 MODULE_LICENSE("GPL v2");
483 MODULE_IMPORT_NS("IIO_AD_SIGMA_DELTA");
484