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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 | ||
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 | ||
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 | ||
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_LOW, | |
257 | }; | |
258 | ||
259 | static int ad7791_read_raw(struct iio_dev *indio_dev, | |
260 | const struct iio_chan_spec *chan, int *val, int *val2, long info) | |
261 | { | |
262 | struct ad7791_state *st = iio_priv(indio_dev); | |
263 | bool unipolar = !!(st->mode & AD7791_MODE_UNIPOLAR); | |
264 | unsigned int rate; | |
265 | ||
266 | switch (info) { | |
267 | case IIO_CHAN_INFO_RAW: | |
268 | return ad_sigma_delta_single_conversion(indio_dev, chan, val); | |
269 | case IIO_CHAN_INFO_OFFSET: | |
270 | /** | |
271 | * Unipolar: 0 to VREF | |
272 | * Bipolar -VREF to VREF | |
273 | **/ | |
274 | if (unipolar) | |
275 | *val = 0; | |
276 | else | |
277 | *val = -(1 << (chan->scan_type.realbits - 1)); | |
278 | return IIO_VAL_INT; | |
279 | case IIO_CHAN_INFO_SCALE: | |
280 | /* The monitor channel uses an internal reference. */ | |
281 | if (chan->address == AD7791_CH_AVDD_MONITOR) { | |
282 | /* | |
283 | * The signal is attenuated by a factor of 5 and | |
284 | * compared against a 1.17V internal reference. | |
285 | */ | |
286 | *val = 1170 * 5; | |
287 | } else { | |
288 | int voltage_uv; | |
289 | ||
290 | voltage_uv = regulator_get_voltage(st->reg); | |
291 | if (voltage_uv < 0) | |
292 | return voltage_uv; | |
293 | ||
294 | *val = voltage_uv / 1000; | |
295 | } | |
296 | if (unipolar) | |
297 | *val2 = chan->scan_type.realbits; | |
298 | else | |
299 | *val2 = chan->scan_type.realbits - 1; | |
300 | ||
301 | return IIO_VAL_FRACTIONAL_LOG2; | |
302 | case IIO_CHAN_INFO_SAMP_FREQ: | |
303 | rate = st->filter & AD7791_FILTER_RATE_MASK; | |
304 | *val = ad7791_sample_freq_avail[rate][0]; | |
305 | *val2 = ad7791_sample_freq_avail[rate][1]; | |
306 | return IIO_VAL_INT_PLUS_MICRO; | |
307 | } | |
308 | ||
309 | return -EINVAL; | |
310 | } | |
311 | ||
312 | static int ad7791_write_raw(struct iio_dev *indio_dev, | |
313 | struct iio_chan_spec const *chan, int val, int val2, long mask) | |
314 | { | |
315 | struct ad7791_state *st = iio_priv(indio_dev); | |
316 | int ret, i; | |
317 | ||
318 | ret = iio_device_claim_direct_mode(indio_dev); | |
319 | if (ret) | |
320 | return ret; | |
321 | ||
322 | switch (mask) { | |
323 | case IIO_CHAN_INFO_SAMP_FREQ: | |
324 | for (i = 0; i < ARRAY_SIZE(ad7791_sample_freq_avail); i++) { | |
325 | if (ad7791_sample_freq_avail[i][0] == val && | |
326 | ad7791_sample_freq_avail[i][1] == val2) | |
327 | break; | |
328 | } | |
329 | ||
330 | if (i == ARRAY_SIZE(ad7791_sample_freq_avail)) { | |
331 | ret = -EINVAL; | |
332 | break; | |
333 | } | |
334 | ||
335 | st->filter &= ~AD7791_FILTER_RATE_MASK; | |
336 | st->filter |= i; | |
337 | ad_sd_write_reg(&st->sd, AD7791_REG_FILTER, | |
338 | sizeof(st->filter), | |
339 | st->filter); | |
340 | break; | |
341 | default: | |
342 | ret = -EINVAL; | |
343 | } | |
344 | ||
345 | iio_device_release_direct_mode(indio_dev); | |
346 | return ret; | |
347 | } | |
348 | ||
349 | static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("120 100 33.3 20 16.7 16.6 13.3 9.5"); | |
350 | ||
351 | static struct attribute *ad7791_attributes[] = { | |
352 | &iio_const_attr_sampling_frequency_available.dev_attr.attr, | |
353 | NULL | |
354 | }; | |
355 | ||
356 | static const struct attribute_group ad7791_attribute_group = { | |
357 | .attrs = ad7791_attributes, | |
358 | }; | |
359 | ||
360 | static const struct iio_info ad7791_info = { | |
361 | .read_raw = &ad7791_read_raw, | |
362 | .write_raw = &ad7791_write_raw, | |
363 | .attrs = &ad7791_attribute_group, | |
364 | .validate_trigger = ad_sd_validate_trigger, | |
365 | }; | |
366 | ||
367 | static const struct iio_info ad7791_no_filter_info = { | |
368 | .read_raw = &ad7791_read_raw, | |
369 | .write_raw = &ad7791_write_raw, | |
370 | .validate_trigger = ad_sd_validate_trigger, | |
371 | }; | |
372 | ||
373 | static int ad7791_setup(struct ad7791_state *st, | |
374 | struct ad7791_platform_data *pdata) | |
375 | { | |
376 | /* Set to poweron-reset default values */ | |
377 | st->mode = AD7791_MODE_BUFFER; | |
378 | st->filter = AD7791_FILTER_RATE_16_6; | |
379 | ||
380 | if (!pdata) | |
381 | return 0; | |
382 | ||
383 | if ((st->info->flags & AD7791_FLAG_HAS_BUFFER) && !pdata->buffered) | |
384 | st->mode &= ~AD7791_MODE_BUFFER; | |
385 | ||
386 | if ((st->info->flags & AD7791_FLAG_HAS_BURNOUT) && | |
387 | pdata->burnout_current) | |
388 | st->mode |= AD7791_MODE_BURNOUT; | |
389 | ||
390 | if ((st->info->flags & AD7791_FLAG_HAS_UNIPOLAR) && pdata->unipolar) | |
391 | st->mode |= AD7791_MODE_UNIPOLAR; | |
392 | ||
393 | return ad_sd_write_reg(&st->sd, AD7791_REG_MODE, sizeof(st->mode), | |
394 | st->mode); | |
395 | } | |
396 | ||
397 | static void ad7791_reg_disable(void *reg) | |
398 | { | |
399 | regulator_disable(reg); | |
400 | } | |
401 | ||
402 | static int ad7791_probe(struct spi_device *spi) | |
403 | { | |
404 | struct ad7791_platform_data *pdata = spi->dev.platform_data; | |
405 | struct iio_dev *indio_dev; | |
406 | struct ad7791_state *st; | |
407 | int ret; | |
408 | ||
409 | if (!spi->irq) { | |
410 | dev_err(&spi->dev, "Missing IRQ.\n"); | |
411 | return -ENXIO; | |
412 | } | |
413 | ||
414 | indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); | |
415 | if (!indio_dev) | |
416 | return -ENOMEM; | |
417 | ||
418 | st = iio_priv(indio_dev); | |
419 | ||
420 | st->reg = devm_regulator_get(&spi->dev, "refin"); | |
421 | if (IS_ERR(st->reg)) | |
422 | return PTR_ERR(st->reg); | |
423 | ||
424 | ret = regulator_enable(st->reg); | |
425 | if (ret) | |
426 | return ret; | |
427 | ||
428 | ret = devm_add_action_or_reset(&spi->dev, ad7791_reg_disable, st->reg); | |
429 | if (ret) | |
430 | return ret; | |
431 | ||
432 | st->info = &ad7791_chip_infos[spi_get_device_id(spi)->driver_data]; | |
433 | ad_sd_init(&st->sd, indio_dev, spi, &ad7791_sigma_delta_info); | |
434 | ||
435 | indio_dev->name = spi_get_device_id(spi)->name; | |
436 | indio_dev->modes = INDIO_DIRECT_MODE; | |
437 | indio_dev->channels = st->info->channels; | |
438 | indio_dev->num_channels = st->info->num_channels; | |
439 | if (st->info->flags & AD7791_FLAG_HAS_FILTER) | |
440 | indio_dev->info = &ad7791_info; | |
441 | else | |
442 | indio_dev->info = &ad7791_no_filter_info; | |
443 | ||
444 | ret = devm_ad_sd_setup_buffer_and_trigger(&spi->dev, indio_dev); | |
445 | if (ret) | |
446 | return ret; | |
447 | ||
448 | ret = ad7791_setup(st, pdata); | |
449 | if (ret) | |
450 | return ret; | |
451 | ||
452 | return devm_iio_device_register(&spi->dev, indio_dev); | |
453 | } | |
454 | ||
455 | static const struct spi_device_id ad7791_spi_ids[] = { | |
456 | { "ad7787", AD7787 }, | |
457 | { "ad7788", AD7788 }, | |
458 | { "ad7789", AD7789 }, | |
459 | { "ad7790", AD7790 }, | |
460 | { "ad7791", AD7791 }, | |
461 | {} | |
462 | }; | |
463 | MODULE_DEVICE_TABLE(spi, ad7791_spi_ids); | |
464 | ||
465 | static struct spi_driver ad7791_driver = { | |
466 | .driver = { | |
467 | .name = "ad7791", | |
468 | }, | |
469 | .probe = ad7791_probe, | |
470 | .id_table = ad7791_spi_ids, | |
471 | }; | |
472 | module_spi_driver(ad7791_driver); | |
473 | ||
474 | MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); | |
475 | MODULE_DESCRIPTION("Analog Devices AD7787/AD7788/AD7789/AD7790/AD7791 ADC driver"); | |
476 | MODULE_LICENSE("GPL v2"); |