1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * AD7170/AD7171 and AD7780/AD7781 SPI ADC driver |
4 | * |
5 | * Copyright 2011 Analog Devices Inc. |
6 | * Copyright 2019 Renato Lui Geh |
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/gpio/consumer.h> |
19 | #include <linux/module.h> |
20 | #include <linux/bits.h> |
21 | |
22 | #include <linux/iio/iio.h> |
23 | #include <linux/iio/sysfs.h> |
24 | #include <linux/iio/adc/ad_sigma_delta.h> |
25 | |
26 | #define AD7780_RDY BIT(7) |
27 | #define AD7780_FILTER BIT(6) |
28 | #define AD7780_ERR BIT(5) |
29 | #define AD7780_ID1 BIT(4) |
30 | #define AD7780_ID0 BIT(3) |
31 | #define AD7780_GAIN BIT(2) |
32 | |
33 | #define AD7170_ID 0 |
34 | #define AD7171_ID 1 |
35 | #define AD7780_ID 1 |
36 | #define AD7781_ID 0 |
37 | |
38 | #define AD7780_ID_MASK (AD7780_ID0 | AD7780_ID1) |
39 | |
40 | #define AD7780_PATTERN_GOOD 1 |
41 | #define AD7780_PATTERN_MASK GENMASK(1, 0) |
42 | |
43 | #define AD7170_PATTERN_GOOD 5 |
44 | #define AD7170_PATTERN_MASK GENMASK(2, 0) |
45 | |
46 | #define AD7780_GAIN_MIDPOINT 64 |
47 | #define AD7780_FILTER_MIDPOINT 13350 |
48 | |
49 | static const unsigned int ad778x_gain[2] = { 1, 128 }; |
50 | static const unsigned int ad778x_odr_avail[2] = { 10000, 16700 }; |
51 | |
52 | struct ad7780_chip_info { |
53 | struct iio_chan_spec channel; |
54 | unsigned int pattern_mask; |
55 | unsigned int pattern; |
56 | bool is_ad778x; |
57 | }; |
58 | |
59 | struct ad7780_state { |
60 | const struct ad7780_chip_info *chip_info; |
61 | struct regulator *reg; |
62 | struct gpio_desc *powerdown_gpio; |
63 | struct gpio_desc *gain_gpio; |
64 | struct gpio_desc *filter_gpio; |
65 | unsigned int gain; |
66 | unsigned int odr; |
67 | unsigned int int_vref_mv; |
68 | |
69 | struct ad_sigma_delta sd; |
70 | }; |
71 | |
72 | enum ad7780_supported_device_ids { |
73 | ID_AD7170, |
74 | ID_AD7171, |
75 | ID_AD7780, |
76 | ID_AD7781, |
77 | }; |
78 | |
79 | static struct ad7780_state *ad_sigma_delta_to_ad7780(struct ad_sigma_delta *sd) |
80 | { |
81 | return container_of(sd, struct ad7780_state, sd); |
82 | } |
83 | |
84 | static int ad7780_set_mode(struct ad_sigma_delta *sigma_delta, |
85 | enum ad_sigma_delta_mode mode) |
86 | { |
87 | struct ad7780_state *st = ad_sigma_delta_to_ad7780(sd: sigma_delta); |
88 | unsigned int val; |
89 | |
90 | switch (mode) { |
91 | case AD_SD_MODE_SINGLE: |
92 | case AD_SD_MODE_CONTINUOUS: |
93 | val = 1; |
94 | break; |
95 | default: |
96 | val = 0; |
97 | break; |
98 | } |
99 | |
100 | gpiod_set_value(desc: st->powerdown_gpio, value: val); |
101 | |
102 | return 0; |
103 | } |
104 | |
105 | static int ad7780_read_raw(struct iio_dev *indio_dev, |
106 | struct iio_chan_spec const *chan, |
107 | int *val, |
108 | int *val2, |
109 | long m) |
110 | { |
111 | struct ad7780_state *st = iio_priv(indio_dev); |
112 | int voltage_uv; |
113 | |
114 | switch (m) { |
115 | case IIO_CHAN_INFO_RAW: |
116 | return ad_sigma_delta_single_conversion(indio_dev, chan, val); |
117 | case IIO_CHAN_INFO_SCALE: |
118 | voltage_uv = regulator_get_voltage(regulator: st->reg); |
119 | if (voltage_uv < 0) |
120 | return voltage_uv; |
121 | voltage_uv /= 1000; |
122 | *val = voltage_uv * st->gain; |
123 | *val2 = chan->scan_type.realbits - 1; |
124 | st->int_vref_mv = voltage_uv; |
125 | return IIO_VAL_FRACTIONAL_LOG2; |
126 | case IIO_CHAN_INFO_OFFSET: |
127 | *val = -(1 << (chan->scan_type.realbits - 1)); |
128 | return IIO_VAL_INT; |
129 | case IIO_CHAN_INFO_SAMP_FREQ: |
130 | *val = st->odr; |
131 | return IIO_VAL_INT; |
132 | default: |
133 | break; |
134 | } |
135 | |
136 | return -EINVAL; |
137 | } |
138 | |
139 | static int ad7780_write_raw(struct iio_dev *indio_dev, |
140 | struct iio_chan_spec const *chan, |
141 | int val, |
142 | int val2, |
143 | long m) |
144 | { |
145 | struct ad7780_state *st = iio_priv(indio_dev); |
146 | const struct ad7780_chip_info *chip_info = st->chip_info; |
147 | unsigned long long vref; |
148 | unsigned int full_scale, gain; |
149 | |
150 | if (!chip_info->is_ad778x) |
151 | return -EINVAL; |
152 | |
153 | switch (m) { |
154 | case IIO_CHAN_INFO_SCALE: |
155 | if (val != 0) |
156 | return -EINVAL; |
157 | |
158 | vref = st->int_vref_mv * 1000000LL; |
159 | full_scale = 1 << (chip_info->channel.scan_type.realbits - 1); |
160 | gain = DIV_ROUND_CLOSEST_ULL(vref, full_scale); |
161 | gain = DIV_ROUND_CLOSEST(gain, val2); |
162 | st->gain = gain; |
163 | if (gain < AD7780_GAIN_MIDPOINT) |
164 | gain = 0; |
165 | else |
166 | gain = 1; |
167 | gpiod_set_value(desc: st->gain_gpio, value: gain); |
168 | break; |
169 | case IIO_CHAN_INFO_SAMP_FREQ: |
170 | if (1000*val + val2/1000 < AD7780_FILTER_MIDPOINT) |
171 | val = 0; |
172 | else |
173 | val = 1; |
174 | st->odr = ad778x_odr_avail[val]; |
175 | gpiod_set_value(desc: st->filter_gpio, value: val); |
176 | break; |
177 | default: |
178 | break; |
179 | } |
180 | |
181 | return 0; |
182 | } |
183 | |
184 | static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta, |
185 | unsigned int raw_sample) |
186 | { |
187 | struct ad7780_state *st = ad_sigma_delta_to_ad7780(sd: sigma_delta); |
188 | const struct ad7780_chip_info *chip_info = st->chip_info; |
189 | |
190 | if ((raw_sample & AD7780_ERR) || |
191 | ((raw_sample & chip_info->pattern_mask) != chip_info->pattern)) |
192 | return -EIO; |
193 | |
194 | if (chip_info->is_ad778x) { |
195 | st->gain = ad778x_gain[raw_sample & AD7780_GAIN]; |
196 | st->odr = ad778x_odr_avail[raw_sample & AD7780_FILTER]; |
197 | } |
198 | |
199 | return 0; |
200 | } |
201 | |
202 | static const struct ad_sigma_delta_info ad7780_sigma_delta_info = { |
203 | .set_mode = ad7780_set_mode, |
204 | .postprocess_sample = ad7780_postprocess_sample, |
205 | .has_registers = false, |
206 | .irq_flags = IRQF_TRIGGER_FALLING, |
207 | }; |
208 | |
209 | #define _AD7780_CHANNEL(_bits, _wordsize, _mask_all) \ |
210 | { \ |
211 | .type = IIO_VOLTAGE, \ |
212 | .indexed = 1, \ |
213 | .channel = 0, \ |
214 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ |
215 | BIT(IIO_CHAN_INFO_OFFSET), \ |
216 | .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ |
217 | .info_mask_shared_by_all = _mask_all, \ |
218 | .scan_index = 1, \ |
219 | .scan_type = { \ |
220 | .sign = 'u', \ |
221 | .realbits = (_bits), \ |
222 | .storagebits = 32, \ |
223 | .shift = (_wordsize) - (_bits), \ |
224 | .endianness = IIO_BE, \ |
225 | }, \ |
226 | } |
227 | |
228 | #define AD7780_CHANNEL(_bits, _wordsize) \ |
229 | _AD7780_CHANNEL(_bits, _wordsize, BIT(IIO_CHAN_INFO_SAMP_FREQ)) |
230 | #define AD7170_CHANNEL(_bits, _wordsize) \ |
231 | _AD7780_CHANNEL(_bits, _wordsize, 0) |
232 | |
233 | static const struct ad7780_chip_info ad7780_chip_info_tbl[] = { |
234 | [ID_AD7170] = { |
235 | .channel = AD7170_CHANNEL(12, 24), |
236 | .pattern = AD7170_PATTERN_GOOD, |
237 | .pattern_mask = AD7170_PATTERN_MASK, |
238 | .is_ad778x = false, |
239 | }, |
240 | [ID_AD7171] = { |
241 | .channel = AD7170_CHANNEL(16, 24), |
242 | .pattern = AD7170_PATTERN_GOOD, |
243 | .pattern_mask = AD7170_PATTERN_MASK, |
244 | .is_ad778x = false, |
245 | }, |
246 | [ID_AD7780] = { |
247 | .channel = AD7780_CHANNEL(24, 32), |
248 | .pattern = AD7780_PATTERN_GOOD, |
249 | .pattern_mask = AD7780_PATTERN_MASK, |
250 | .is_ad778x = true, |
251 | }, |
252 | [ID_AD7781] = { |
253 | .channel = AD7780_CHANNEL(20, 32), |
254 | .pattern = AD7780_PATTERN_GOOD, |
255 | .pattern_mask = AD7780_PATTERN_MASK, |
256 | .is_ad778x = true, |
257 | }, |
258 | }; |
259 | |
260 | static const struct iio_info ad7780_info = { |
261 | .read_raw = ad7780_read_raw, |
262 | .write_raw = ad7780_write_raw, |
263 | }; |
264 | |
265 | static int ad7780_init_gpios(struct device *dev, struct ad7780_state *st) |
266 | { |
267 | int ret; |
268 | |
269 | st->powerdown_gpio = devm_gpiod_get_optional(dev, |
270 | con_id: "powerdown" , |
271 | flags: GPIOD_OUT_LOW); |
272 | if (IS_ERR(ptr: st->powerdown_gpio)) { |
273 | ret = PTR_ERR(ptr: st->powerdown_gpio); |
274 | dev_err(dev, "Failed to request powerdown GPIO: %d\n" , ret); |
275 | return ret; |
276 | } |
277 | |
278 | if (!st->chip_info->is_ad778x) |
279 | return 0; |
280 | |
281 | |
282 | st->gain_gpio = devm_gpiod_get_optional(dev, |
283 | con_id: "adi,gain" , |
284 | flags: GPIOD_OUT_HIGH); |
285 | if (IS_ERR(ptr: st->gain_gpio)) { |
286 | ret = PTR_ERR(ptr: st->gain_gpio); |
287 | dev_err(dev, "Failed to request gain GPIO: %d\n" , ret); |
288 | return ret; |
289 | } |
290 | |
291 | st->filter_gpio = devm_gpiod_get_optional(dev, |
292 | con_id: "adi,filter" , |
293 | flags: GPIOD_OUT_HIGH); |
294 | if (IS_ERR(ptr: st->filter_gpio)) { |
295 | ret = PTR_ERR(ptr: st->filter_gpio); |
296 | dev_err(dev, "Failed to request filter GPIO: %d\n" , ret); |
297 | return ret; |
298 | } |
299 | |
300 | return 0; |
301 | } |
302 | |
303 | static void ad7780_reg_disable(void *reg) |
304 | { |
305 | regulator_disable(regulator: reg); |
306 | } |
307 | |
308 | static int ad7780_probe(struct spi_device *spi) |
309 | { |
310 | struct ad7780_state *st; |
311 | struct iio_dev *indio_dev; |
312 | int ret; |
313 | |
314 | indio_dev = devm_iio_device_alloc(parent: &spi->dev, sizeof_priv: sizeof(*st)); |
315 | if (!indio_dev) |
316 | return -ENOMEM; |
317 | |
318 | st = iio_priv(indio_dev); |
319 | st->gain = 1; |
320 | |
321 | ad_sd_init(sigma_delta: &st->sd, indio_dev, spi, info: &ad7780_sigma_delta_info); |
322 | |
323 | st->chip_info = |
324 | &ad7780_chip_info_tbl[spi_get_device_id(sdev: spi)->driver_data]; |
325 | |
326 | indio_dev->name = spi_get_device_id(sdev: spi)->name; |
327 | indio_dev->modes = INDIO_DIRECT_MODE; |
328 | indio_dev->channels = &st->chip_info->channel; |
329 | indio_dev->num_channels = 1; |
330 | indio_dev->info = &ad7780_info; |
331 | |
332 | ret = ad7780_init_gpios(dev: &spi->dev, st); |
333 | if (ret) |
334 | return ret; |
335 | |
336 | st->reg = devm_regulator_get(dev: &spi->dev, id: "avdd" ); |
337 | if (IS_ERR(ptr: st->reg)) |
338 | return PTR_ERR(ptr: st->reg); |
339 | |
340 | ret = regulator_enable(regulator: st->reg); |
341 | if (ret) { |
342 | dev_err(&spi->dev, "Failed to enable specified AVdd supply\n" ); |
343 | return ret; |
344 | } |
345 | |
346 | ret = devm_add_action_or_reset(&spi->dev, ad7780_reg_disable, st->reg); |
347 | if (ret) |
348 | return ret; |
349 | |
350 | ret = devm_ad_sd_setup_buffer_and_trigger(dev: &spi->dev, indio_dev); |
351 | if (ret) |
352 | return ret; |
353 | |
354 | return devm_iio_device_register(&spi->dev, indio_dev); |
355 | } |
356 | |
357 | static const struct spi_device_id ad7780_id[] = { |
358 | {"ad7170" , ID_AD7170}, |
359 | {"ad7171" , ID_AD7171}, |
360 | {"ad7780" , ID_AD7780}, |
361 | {"ad7781" , ID_AD7781}, |
362 | {} |
363 | }; |
364 | MODULE_DEVICE_TABLE(spi, ad7780_id); |
365 | |
366 | static struct spi_driver ad7780_driver = { |
367 | .driver = { |
368 | .name = "ad7780" , |
369 | }, |
370 | .probe = ad7780_probe, |
371 | .id_table = ad7780_id, |
372 | }; |
373 | module_spi_driver(ad7780_driver); |
374 | |
375 | MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>" ); |
376 | MODULE_DESCRIPTION("Analog Devices AD7780 and similar ADCs" ); |
377 | MODULE_LICENSE("GPL v2" ); |
378 | MODULE_IMPORT_NS(IIO_AD_SIGMA_DELTA); |
379 | |