Commit | Line | Data |
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7b123c85 LPC |
1 | /* |
2 | * AD7787/AD7788/AD7789/AD7790/AD7791 SPI ADC driver | |
3 | * | |
4 | * Copyright 2012 Analog Devices Inc. | |
5 | * Author: Lars-Peter Clausen <lars@metafoo.de> | |
6 | * | |
7 | * Licensed under the GPL-2. | |
8 | */ | |
9 | ||
10 | #include <linux/interrupt.h> | |
11 | #include <linux/device.h> | |
12 | #include <linux/kernel.h> | |
13 | #include <linux/slab.h> | |
14 | #include <linux/sysfs.h> | |
15 | #include <linux/spi/spi.h> | |
16 | #include <linux/regulator/consumer.h> | |
17 | #include <linux/err.h> | |
18 | #include <linux/sched.h> | |
19 | #include <linux/delay.h> | |
20 | #include <linux/module.h> | |
21 | ||
22 | #include <linux/iio/iio.h> | |
23 | #include <linux/iio/sysfs.h> | |
24 | #include <linux/iio/buffer.h> | |
25 | #include <linux/iio/trigger.h> | |
26 | #include <linux/iio/trigger_consumer.h> | |
27 | #include <linux/iio/triggered_buffer.h> | |
28 | #include <linux/iio/adc/ad_sigma_delta.h> | |
29 | ||
30 | #include <linux/platform_data/ad7791.h> | |
31 | ||
32 | #define AD7791_REG_COMM 0x0 /* For writes */ | |
33 | #define AD7791_REG_STATUS 0x0 /* For reads */ | |
34 | #define AD7791_REG_MODE 0x1 | |
35 | #define AD7791_REG_FILTER 0x2 | |
36 | #define AD7791_REG_DATA 0x3 | |
37 | ||
38 | #define AD7791_MODE_CONTINUOUS 0x00 | |
39 | #define AD7791_MODE_SINGLE 0x02 | |
40 | #define AD7791_MODE_POWERDOWN 0x03 | |
41 | ||
42 | #define AD7791_CH_AIN1P_AIN1N 0x00 | |
43 | #define AD7791_CH_AIN2 0x01 | |
44 | #define AD7791_CH_AIN1N_AIN1N 0x02 | |
45 | #define AD7791_CH_AVDD_MONITOR 0x03 | |
46 | ||
47 | #define AD7791_FILTER_CLK_DIV_1 (0x0 << 4) | |
48 | #define AD7791_FILTER_CLK_DIV_2 (0x1 << 4) | |
49 | #define AD7791_FILTER_CLK_DIV_4 (0x2 << 4) | |
50 | #define AD7791_FILTER_CLK_DIV_8 (0x3 << 4) | |
51 | #define AD7791_FILTER_CLK_MASK (0x3 << 4) | |
52 | #define AD7791_FILTER_RATE_120 0x0 | |
53 | #define AD7791_FILTER_RATE_100 0x1 | |
54 | #define AD7791_FILTER_RATE_33_3 0x2 | |
55 | #define AD7791_FILTER_RATE_20 0x3 | |
56 | #define AD7791_FILTER_RATE_16_6 0x4 | |
57 | #define AD7791_FILTER_RATE_16_7 0x5 | |
58 | #define AD7791_FILTER_RATE_13_3 0x6 | |
59 | #define AD7791_FILTER_RATE_9_5 0x7 | |
60 | #define AD7791_FILTER_RATE_MASK 0x7 | |
61 | ||
62 | #define AD7791_MODE_BUFFER BIT(1) | |
63 | #define AD7791_MODE_UNIPOLAR BIT(2) | |
64 | #define AD7791_MODE_BURNOUT BIT(3) | |
65 | #define AD7791_MODE_SEL_MASK (0x3 << 6) | |
66 | #define AD7791_MODE_SEL(x) ((x) << 6) | |
67 | ||
68 | #define DECLARE_AD7787_CHANNELS(name, bits, storagebits) \ | |
69 | const struct iio_chan_spec name[] = { \ | |
70 | AD_SD_DIFF_CHANNEL(0, 0, 0, AD7791_CH_AIN1P_AIN1N, \ | |
71 | (bits), (storagebits), 0), \ | |
72 | AD_SD_CHANNEL(1, 1, AD7791_CH_AIN2, (bits), (storagebits), 0), \ | |
73 | AD_SD_SHORTED_CHANNEL(2, 0, AD7791_CH_AIN1N_AIN1N, \ | |
74 | (bits), (storagebits), 0), \ | |
75 | AD_SD_SUPPLY_CHANNEL(3, 2, AD7791_CH_AVDD_MONITOR, \ | |
76 | (bits), (storagebits), 0), \ | |
77 | IIO_CHAN_SOFT_TIMESTAMP(4), \ | |
78 | } | |
79 | ||
80 | #define DECLARE_AD7791_CHANNELS(name, bits, storagebits) \ | |
81 | const struct iio_chan_spec name[] = { \ | |
82 | AD_SD_DIFF_CHANNEL(0, 0, 0, AD7791_CH_AIN1P_AIN1N, \ | |
83 | (bits), (storagebits), 0), \ | |
84 | AD_SD_SHORTED_CHANNEL(1, 0, AD7791_CH_AIN1N_AIN1N, \ | |
85 | (bits), (storagebits), 0), \ | |
86 | AD_SD_SUPPLY_CHANNEL(2, 1, AD7791_CH_AVDD_MONITOR, \ | |
87 | (bits), (storagebits), 0), \ | |
88 | IIO_CHAN_SOFT_TIMESTAMP(3), \ | |
89 | } | |
90 | ||
91 | static DECLARE_AD7787_CHANNELS(ad7787_channels, 24, 32); | |
92 | static DECLARE_AD7791_CHANNELS(ad7790_channels, 16, 16); | |
93 | static DECLARE_AD7791_CHANNELS(ad7791_channels, 24, 32); | |
94 | ||
95 | enum { | |
96 | AD7787, | |
97 | AD7788, | |
98 | AD7789, | |
99 | AD7790, | |
100 | AD7791, | |
101 | }; | |
102 | ||
103 | enum ad7791_chip_info_flags { | |
104 | AD7791_FLAG_HAS_FILTER = (1 << 0), | |
105 | AD7791_FLAG_HAS_BUFFER = (1 << 1), | |
106 | AD7791_FLAG_HAS_UNIPOLAR = (1 << 2), | |
107 | AD7791_FLAG_HAS_BURNOUT = (1 << 3), | |
108 | }; | |
109 | ||
110 | struct ad7791_chip_info { | |
111 | const struct iio_chan_spec *channels; | |
112 | unsigned int num_channels; | |
113 | enum ad7791_chip_info_flags flags; | |
114 | }; | |
115 | ||
116 | static const struct ad7791_chip_info ad7791_chip_infos[] = { | |
117 | [AD7787] = { | |
118 | .channels = ad7787_channels, | |
119 | .num_channels = ARRAY_SIZE(ad7787_channels), | |
120 | .flags = AD7791_FLAG_HAS_FILTER | AD7791_FLAG_HAS_BUFFER | | |
121 | AD7791_FLAG_HAS_UNIPOLAR | AD7791_FLAG_HAS_BURNOUT, | |
122 | }, | |
123 | [AD7788] = { | |
124 | .channels = ad7790_channels, | |
125 | .num_channels = ARRAY_SIZE(ad7790_channels), | |
126 | .flags = AD7791_FLAG_HAS_UNIPOLAR, | |
127 | }, | |
128 | [AD7789] = { | |
129 | .channels = ad7791_channels, | |
130 | .num_channels = ARRAY_SIZE(ad7791_channels), | |
131 | .flags = AD7791_FLAG_HAS_UNIPOLAR, | |
132 | }, | |
133 | [AD7790] = { | |
134 | .channels = ad7790_channels, | |
135 | .num_channels = ARRAY_SIZE(ad7790_channels), | |
136 | .flags = AD7791_FLAG_HAS_FILTER | AD7791_FLAG_HAS_BUFFER | | |
137 | AD7791_FLAG_HAS_BURNOUT, | |
138 | }, | |
139 | [AD7791] = { | |
140 | .channels = ad7791_channels, | |
141 | .num_channels = ARRAY_SIZE(ad7791_channels), | |
142 | .flags = AD7791_FLAG_HAS_FILTER | AD7791_FLAG_HAS_BUFFER | | |
143 | AD7791_FLAG_HAS_UNIPOLAR | AD7791_FLAG_HAS_BURNOUT, | |
144 | }, | |
145 | }; | |
146 | ||
147 | struct ad7791_state { | |
148 | struct ad_sigma_delta sd; | |
149 | uint8_t mode; | |
150 | uint8_t filter; | |
151 | ||
152 | struct regulator *reg; | |
153 | const struct ad7791_chip_info *info; | |
154 | }; | |
155 | ||
156 | static struct ad7791_state *ad_sigma_delta_to_ad7791(struct ad_sigma_delta *sd) | |
157 | { | |
158 | return container_of(sd, struct ad7791_state, sd); | |
159 | } | |
160 | ||
161 | static int ad7791_set_channel(struct ad_sigma_delta *sd, unsigned int channel) | |
162 | { | |
163 | ad_sd_set_comm(sd, channel); | |
164 | ||
165 | return 0; | |
166 | } | |
167 | ||
168 | static int ad7791_set_mode(struct ad_sigma_delta *sd, | |
169 | enum ad_sigma_delta_mode mode) | |
170 | { | |
171 | struct ad7791_state *st = ad_sigma_delta_to_ad7791(sd); | |
172 | ||
173 | switch (mode) { | |
174 | case AD_SD_MODE_CONTINUOUS: | |
175 | mode = AD7791_MODE_CONTINUOUS; | |
176 | break; | |
177 | case AD_SD_MODE_SINGLE: | |
178 | mode = AD7791_MODE_SINGLE; | |
179 | break; | |
180 | case AD_SD_MODE_IDLE: | |
181 | case AD_SD_MODE_POWERDOWN: | |
182 | mode = AD7791_MODE_POWERDOWN; | |
183 | break; | |
184 | } | |
185 | ||
186 | st->mode &= ~AD7791_MODE_SEL_MASK; | |
187 | st->mode |= AD7791_MODE_SEL(mode); | |
188 | ||
189 | return ad_sd_write_reg(sd, AD7791_REG_MODE, sizeof(st->mode), st->mode); | |
190 | } | |
191 | ||
192 | static const struct ad_sigma_delta_info ad7791_sigma_delta_info = { | |
193 | .set_channel = ad7791_set_channel, | |
194 | .set_mode = ad7791_set_mode, | |
195 | .has_registers = true, | |
196 | .addr_shift = 4, | |
197 | .read_mask = BIT(3), | |
198 | }; | |
199 | ||
200 | static int ad7791_read_raw(struct iio_dev *indio_dev, | |
201 | const struct iio_chan_spec *chan, int *val, int *val2, long info) | |
202 | { | |
203 | struct ad7791_state *st = iio_priv(indio_dev); | |
204 | bool unipolar = !!(st->mode & AD7791_MODE_UNIPOLAR); | |
7b123c85 LPC |
205 | |
206 | switch (info) { | |
207 | case IIO_CHAN_INFO_RAW: | |
208 | return ad_sigma_delta_single_conversion(indio_dev, chan, val); | |
209 | case IIO_CHAN_INFO_OFFSET: | |
210 | /** | |
211 | * Unipolar: 0 to VREF | |
212 | * Bipolar -VREF to VREF | |
213 | **/ | |
214 | if (unipolar) | |
215 | *val = 0; | |
216 | else | |
217 | *val = -(1 << (chan->scan_type.realbits - 1)); | |
218 | return IIO_VAL_INT; | |
219 | case IIO_CHAN_INFO_SCALE: | |
220 | /* The monitor channel uses an internal reference. */ | |
221 | if (chan->address == AD7791_CH_AVDD_MONITOR) { | |
488a2182 LPC |
222 | /* |
223 | * The signal is attenuated by a factor of 5 and | |
224 | * compared against a 1.17V internal reference. | |
225 | */ | |
226 | *val = 1170 * 5; | |
7b123c85 LPC |
227 | } else { |
228 | int voltage_uv; | |
229 | ||
230 | voltage_uv = regulator_get_voltage(st->reg); | |
231 | if (voltage_uv < 0) | |
232 | return voltage_uv; | |
488a2182 LPC |
233 | |
234 | *val = voltage_uv / 1000; | |
7b123c85 LPC |
235 | } |
236 | if (unipolar) | |
488a2182 | 237 | *val2 = chan->scan_type.realbits; |
7b123c85 | 238 | else |
488a2182 | 239 | *val2 = chan->scan_type.realbits - 1; |
7b123c85 | 240 | |
488a2182 | 241 | return IIO_VAL_FRACTIONAL_LOG2; |
7b123c85 LPC |
242 | } |
243 | ||
244 | return -EINVAL; | |
245 | } | |
246 | ||
247 | static const char * const ad7791_sample_freq_avail[] = { | |
248 | [AD7791_FILTER_RATE_120] = "120", | |
249 | [AD7791_FILTER_RATE_100] = "100", | |
250 | [AD7791_FILTER_RATE_33_3] = "33.3", | |
251 | [AD7791_FILTER_RATE_20] = "20", | |
252 | [AD7791_FILTER_RATE_16_6] = "16.6", | |
253 | [AD7791_FILTER_RATE_16_7] = "16.7", | |
254 | [AD7791_FILTER_RATE_13_3] = "13.3", | |
255 | [AD7791_FILTER_RATE_9_5] = "9.5", | |
256 | }; | |
257 | ||
258 | static ssize_t ad7791_read_frequency(struct device *dev, | |
259 | struct device_attribute *attr, char *buf) | |
260 | { | |
261 | struct iio_dev *indio_dev = dev_to_iio_dev(dev); | |
262 | struct ad7791_state *st = iio_priv(indio_dev); | |
263 | unsigned int rate = st->filter & AD7791_FILTER_RATE_MASK; | |
264 | ||
265 | return sprintf(buf, "%s\n", ad7791_sample_freq_avail[rate]); | |
266 | } | |
267 | ||
268 | static ssize_t ad7791_write_frequency(struct device *dev, | |
269 | struct device_attribute *attr, const char *buf, size_t len) | |
270 | { | |
271 | struct iio_dev *indio_dev = dev_to_iio_dev(dev); | |
272 | struct ad7791_state *st = iio_priv(indio_dev); | |
273 | int i, ret; | |
274 | ||
275 | mutex_lock(&indio_dev->mlock); | |
276 | if (iio_buffer_enabled(indio_dev)) { | |
277 | mutex_unlock(&indio_dev->mlock); | |
278 | return -EBUSY; | |
279 | } | |
280 | mutex_unlock(&indio_dev->mlock); | |
281 | ||
282 | ret = -EINVAL; | |
283 | ||
284 | for (i = 0; i < ARRAY_SIZE(ad7791_sample_freq_avail); i++) { | |
285 | if (sysfs_streq(ad7791_sample_freq_avail[i], buf)) { | |
286 | ||
287 | mutex_lock(&indio_dev->mlock); | |
288 | st->filter &= ~AD7791_FILTER_RATE_MASK; | |
289 | st->filter |= i; | |
290 | ad_sd_write_reg(&st->sd, AD7791_REG_FILTER, | |
291 | sizeof(st->filter), st->filter); | |
292 | mutex_unlock(&indio_dev->mlock); | |
293 | ret = 0; | |
294 | break; | |
295 | } | |
296 | } | |
297 | ||
298 | return ret ? ret : len; | |
299 | } | |
300 | ||
301 | static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO, | |
302 | ad7791_read_frequency, | |
303 | ad7791_write_frequency); | |
304 | ||
305 | static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("120 100 33.3 20 16.7 16.6 13.3 9.5"); | |
306 | ||
307 | static struct attribute *ad7791_attributes[] = { | |
308 | &iio_dev_attr_sampling_frequency.dev_attr.attr, | |
309 | &iio_const_attr_sampling_frequency_available.dev_attr.attr, | |
310 | NULL | |
311 | }; | |
312 | ||
313 | static const struct attribute_group ad7791_attribute_group = { | |
314 | .attrs = ad7791_attributes, | |
315 | }; | |
316 | ||
317 | static const struct iio_info ad7791_info = { | |
318 | .read_raw = &ad7791_read_raw, | |
319 | .attrs = &ad7791_attribute_group, | |
320 | .validate_trigger = ad_sd_validate_trigger, | |
321 | .driver_module = THIS_MODULE, | |
322 | }; | |
323 | ||
324 | static const struct iio_info ad7791_no_filter_info = { | |
325 | .read_raw = &ad7791_read_raw, | |
326 | .validate_trigger = ad_sd_validate_trigger, | |
327 | .driver_module = THIS_MODULE, | |
328 | }; | |
329 | ||
fc52692c GKH |
330 | static int ad7791_setup(struct ad7791_state *st, |
331 | struct ad7791_platform_data *pdata) | |
7b123c85 LPC |
332 | { |
333 | /* Set to poweron-reset default values */ | |
334 | st->mode = AD7791_MODE_BUFFER; | |
335 | st->filter = AD7791_FILTER_RATE_16_6; | |
336 | ||
337 | if (!pdata) | |
338 | return 0; | |
339 | ||
340 | if ((st->info->flags & AD7791_FLAG_HAS_BUFFER) && !pdata->buffered) | |
341 | st->mode &= ~AD7791_MODE_BUFFER; | |
342 | ||
343 | if ((st->info->flags & AD7791_FLAG_HAS_BURNOUT) && | |
344 | pdata->burnout_current) | |
345 | st->mode |= AD7791_MODE_BURNOUT; | |
346 | ||
347 | if ((st->info->flags & AD7791_FLAG_HAS_UNIPOLAR) && pdata->unipolar) | |
348 | st->mode |= AD7791_MODE_UNIPOLAR; | |
349 | ||
350 | return ad_sd_write_reg(&st->sd, AD7791_REG_MODE, sizeof(st->mode), | |
351 | st->mode); | |
352 | } | |
353 | ||
fc52692c | 354 | static int ad7791_probe(struct spi_device *spi) |
7b123c85 LPC |
355 | { |
356 | struct ad7791_platform_data *pdata = spi->dev.platform_data; | |
357 | struct iio_dev *indio_dev; | |
358 | struct ad7791_state *st; | |
359 | int ret; | |
360 | ||
361 | if (!spi->irq) { | |
362 | dev_err(&spi->dev, "Missing IRQ.\n"); | |
363 | return -ENXIO; | |
364 | } | |
365 | ||
eb8fe607 | 366 | indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); |
7b123c85 LPC |
367 | if (!indio_dev) |
368 | return -ENOMEM; | |
369 | ||
370 | st = iio_priv(indio_dev); | |
371 | ||
eb8fe607 SK |
372 | st->reg = devm_regulator_get(&spi->dev, "refin"); |
373 | if (IS_ERR(st->reg)) | |
374 | return PTR_ERR(st->reg); | |
7b123c85 LPC |
375 | |
376 | ret = regulator_enable(st->reg); | |
377 | if (ret) | |
eb8fe607 | 378 | return ret; |
7b123c85 LPC |
379 | |
380 | st->info = &ad7791_chip_infos[spi_get_device_id(spi)->driver_data]; | |
381 | ad_sd_init(&st->sd, indio_dev, spi, &ad7791_sigma_delta_info); | |
382 | ||
383 | spi_set_drvdata(spi, indio_dev); | |
384 | ||
385 | indio_dev->dev.parent = &spi->dev; | |
386 | indio_dev->name = spi_get_device_id(spi)->name; | |
387 | indio_dev->modes = INDIO_DIRECT_MODE; | |
388 | indio_dev->channels = st->info->channels; | |
389 | indio_dev->num_channels = st->info->num_channels; | |
390 | if (st->info->flags & AD7791_FLAG_HAS_FILTER) | |
391 | indio_dev->info = &ad7791_info; | |
392 | else | |
393 | indio_dev->info = &ad7791_no_filter_info; | |
394 | ||
395 | ret = ad_sd_setup_buffer_and_trigger(indio_dev); | |
396 | if (ret) | |
397 | goto error_disable_reg; | |
398 | ||
399 | ret = ad7791_setup(st, pdata); | |
400 | if (ret) | |
401 | goto error_remove_trigger; | |
402 | ||
403 | ret = iio_device_register(indio_dev); | |
404 | if (ret) | |
405 | goto error_remove_trigger; | |
406 | ||
407 | return 0; | |
408 | ||
409 | error_remove_trigger: | |
410 | ad_sd_cleanup_buffer_and_trigger(indio_dev); | |
411 | error_disable_reg: | |
412 | regulator_disable(st->reg); | |
7b123c85 LPC |
413 | |
414 | return ret; | |
415 | } | |
416 | ||
fc52692c | 417 | static int ad7791_remove(struct spi_device *spi) |
7b123c85 LPC |
418 | { |
419 | struct iio_dev *indio_dev = spi_get_drvdata(spi); | |
420 | struct ad7791_state *st = iio_priv(indio_dev); | |
421 | ||
422 | iio_device_unregister(indio_dev); | |
423 | ad_sd_cleanup_buffer_and_trigger(indio_dev); | |
424 | ||
425 | regulator_disable(st->reg); | |
7b123c85 LPC |
426 | |
427 | return 0; | |
428 | } | |
429 | ||
430 | static const struct spi_device_id ad7791_spi_ids[] = { | |
431 | { "ad7787", AD7787 }, | |
432 | { "ad7788", AD7788 }, | |
433 | { "ad7789", AD7789 }, | |
434 | { "ad7790", AD7790 }, | |
435 | { "ad7791", AD7791 }, | |
436 | {} | |
437 | }; | |
438 | MODULE_DEVICE_TABLE(spi, ad7791_spi_ids); | |
439 | ||
440 | static struct spi_driver ad7791_driver = { | |
441 | .driver = { | |
442 | .name = "ad7791", | |
7b123c85 LPC |
443 | }, |
444 | .probe = ad7791_probe, | |
fc52692c | 445 | .remove = ad7791_remove, |
7b123c85 LPC |
446 | .id_table = ad7791_spi_ids, |
447 | }; | |
448 | module_spi_driver(ad7791_driver); | |
449 | ||
450 | MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); | |
451 | MODULE_DESCRIPTION("Analog Device AD7787/AD7788/AD7789/AD7790/AD7791 ADC driver"); | |
452 | MODULE_LICENSE("GPL v2"); |