1 /*
2 * AD7746 capacitive sensor driver supporting AD7745, AD7746 and AD7747
3 *
4 * Copyright 2011 Analog Devices Inc.
5 *
6 * Licensed under the GPL-2.
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/i2c.h>
15 #include <linux/delay.h>
16 #include <linux/module.h>
17 #include <linux/stat.h>
18
19 #include <linux/iio/iio.h>
20 #include <linux/iio/sysfs.h>
21
22 #include "ad7746.h"
23
24 /*
25 * AD7746 Register Definition
26 */
27
28 #define AD7746_REG_STATUS 0
29 #define AD7746_REG_CAP_DATA_HIGH 1
30 #define AD7746_REG_CAP_DATA_MID 2
31 #define AD7746_REG_CAP_DATA_LOW 3
32 #define AD7746_REG_VT_DATA_HIGH 4
33 #define AD7746_REG_VT_DATA_MID 5
34 #define AD7746_REG_VT_DATA_LOW 6
35 #define AD7746_REG_CAP_SETUP 7
36 #define AD7746_REG_VT_SETUP 8
37 #define AD7746_REG_EXC_SETUP 9
38 #define AD7746_REG_CFG 10
39 #define AD7746_REG_CAPDACA 11
40 #define AD7746_REG_CAPDACB 12
41 #define AD7746_REG_CAP_OFFH 13
42 #define AD7746_REG_CAP_OFFL 14
43 #define AD7746_REG_CAP_GAINH 15
44 #define AD7746_REG_CAP_GAINL 16
45 #define AD7746_REG_VOLT_GAINH 17
46 #define AD7746_REG_VOLT_GAINL 18
47
48 /* Status Register Bit Designations (AD7746_REG_STATUS) */
49 #define AD7746_STATUS_EXCERR (1 << 3)
50 #define AD7746_STATUS_RDY (1 << 2)
51 #define AD7746_STATUS_RDYVT (1 << 1)
52 #define AD7746_STATUS_RDYCAP (1 << 0)
53
54 /* Capacitive Channel Setup Register Bit Designations (AD7746_REG_CAP_SETUP) */
55 #define AD7746_CAPSETUP_CAPEN (1 << 7)
56 #define AD7746_CAPSETUP_CIN2 (1 << 6) /* AD7746 only */
57 #define AD7746_CAPSETUP_CAPDIFF (1 << 5)
58 #define AD7746_CAPSETUP_CACHOP (1 << 0)
59
60 /* Voltage/Temperature Setup Register Bit Designations (AD7746_REG_VT_SETUP) */
61 #define AD7746_VTSETUP_VTEN (1 << 7)
62 #define AD7746_VTSETUP_VTMD_INT_TEMP (0 << 5)
63 #define AD7746_VTSETUP_VTMD_EXT_TEMP (1 << 5)
64 #define AD7746_VTSETUP_VTMD_VDD_MON (2 << 5)
65 #define AD7746_VTSETUP_VTMD_EXT_VIN (3 << 5)
66 #define AD7746_VTSETUP_EXTREF (1 << 4)
67 #define AD7746_VTSETUP_VTSHORT (1 << 1)
68 #define AD7746_VTSETUP_VTCHOP (1 << 0)
69
70 /* Excitation Setup Register Bit Designations (AD7746_REG_EXC_SETUP) */
71 #define AD7746_EXCSETUP_CLKCTRL (1 << 7)
72 #define AD7746_EXCSETUP_EXCON (1 << 6)
73 #define AD7746_EXCSETUP_EXCB (1 << 5)
74 #define AD7746_EXCSETUP_NEXCB (1 << 4)
75 #define AD7746_EXCSETUP_EXCA (1 << 3)
76 #define AD7746_EXCSETUP_NEXCA (1 << 2)
77 #define AD7746_EXCSETUP_EXCLVL(x) (((x) & 0x3) << 0)
78
79 /* Config Register Bit Designations (AD7746_REG_CFG) */
80 #define AD7746_CONF_VTFS(x) ((x) << 6)
81 #define AD7746_CONF_CAPFS(x) ((x) << 3)
82 #define AD7746_CONF_MODE_IDLE (0 << 0)
83 #define AD7746_CONF_MODE_CONT_CONV (1 << 0)
84 #define AD7746_CONF_MODE_SINGLE_CONV (2 << 0)
85 #define AD7746_CONF_MODE_PWRDN (3 << 0)
86 #define AD7746_CONF_MODE_OFFS_CAL (5 << 0)
87 #define AD7746_CONF_MODE_GAIN_CAL (6 << 0)
88
89 /* CAPDAC Register Bit Designations (AD7746_REG_CAPDACx) */
90 #define AD7746_CAPDAC_DACEN (1 << 7)
91 #define AD7746_CAPDAC_DACP(x) ((x) & 0x7F)
92
93 /*
94 * struct ad7746_chip_info - chip specifc information
95 */
96
97 struct ad7746_chip_info {
98 struct i2c_client *client;
99 /*
100 * Capacitive channel digital filter setup;
101 * conversion time/update rate setup per channel
102 */
103 u8 config;
104 u8 cap_setup;
105 u8 vt_setup;
106 u8 capdac[2][2];
107 s8 capdac_set;
108 };
109
110 enum ad7746_chan {
111 VIN,
112 VIN_VDD,
113 TEMP_INT,
114 TEMP_EXT,
115 CIN1,
116 CIN1_DIFF,
117 CIN2,
118 CIN2_DIFF,
119 };
120
121 static const struct iio_chan_spec ad7746_channels[] = {
122 [VIN] = {
123 .type = IIO_VOLTAGE,
124 .indexed = 1,
125 .channel = 0,
126 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
127 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
128 .address = AD7746_REG_VT_DATA_HIGH << 8 |
129 AD7746_VTSETUP_VTMD_EXT_VIN,
130 },
131 [VIN_VDD] = {
132 .type = IIO_VOLTAGE,
133 .indexed = 1,
134 .channel = 1,
135 .extend_name = "supply",
136 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
137 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
138 .address = AD7746_REG_VT_DATA_HIGH << 8 |
139 AD7746_VTSETUP_VTMD_VDD_MON,
140 },
141 [TEMP_INT] = {
142 .type = IIO_TEMP,
143 .indexed = 1,
144 .channel = 0,
145 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
146 .address = AD7746_REG_VT_DATA_HIGH << 8 |
147 AD7746_VTSETUP_VTMD_INT_TEMP,
148 },
149 [TEMP_EXT] = {
150 .type = IIO_TEMP,
151 .indexed = 1,
152 .channel = 1,
153 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
154 .address = AD7746_REG_VT_DATA_HIGH << 8 |
155 AD7746_VTSETUP_VTMD_EXT_TEMP,
156 },
157 [CIN1] = {
158 .type = IIO_CAPACITANCE,
159 .indexed = 1,
160 .channel = 0,
161 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
162 BIT(IIO_CHAN_INFO_CALIBSCALE) | BIT(IIO_CHAN_INFO_OFFSET),
163 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_CALIBBIAS) |
164 BIT(IIO_CHAN_INFO_SCALE),
165 .address = AD7746_REG_CAP_DATA_HIGH << 8,
166 },
167 [CIN1_DIFF] = {
168 .type = IIO_CAPACITANCE,
169 .differential = 1,
170 .indexed = 1,
171 .channel = 0,
172 .channel2 = 2,
173 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
174 BIT(IIO_CHAN_INFO_CALIBSCALE) | BIT(IIO_CHAN_INFO_OFFSET),
175 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_CALIBBIAS) |
176 BIT(IIO_CHAN_INFO_SCALE),
177 .address = AD7746_REG_CAP_DATA_HIGH << 8 |
178 AD7746_CAPSETUP_CAPDIFF
179 },
180 [CIN2] = {
181 .type = IIO_CAPACITANCE,
182 .indexed = 1,
183 .channel = 1,
184 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
185 BIT(IIO_CHAN_INFO_CALIBSCALE) | BIT(IIO_CHAN_INFO_OFFSET),
186 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_CALIBBIAS) |
187 BIT(IIO_CHAN_INFO_SCALE),
188 .address = AD7746_REG_CAP_DATA_HIGH << 8 |
189 AD7746_CAPSETUP_CIN2,
190 },
191 [CIN2_DIFF] = {
192 .type = IIO_CAPACITANCE,
193 .differential = 1,
194 .indexed = 1,
195 .channel = 1,
196 .channel2 = 3,
197 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
198 BIT(IIO_CHAN_INFO_CALIBSCALE) | BIT(IIO_CHAN_INFO_OFFSET),
199 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_CALIBBIAS) |
200 BIT(IIO_CHAN_INFO_SCALE),
201 .address = AD7746_REG_CAP_DATA_HIGH << 8 |
202 AD7746_CAPSETUP_CAPDIFF | AD7746_CAPSETUP_CIN2,
203 }
204 };
205
206 /* Values are Update Rate (Hz), Conversion Time (ms) + 1*/
207 static const unsigned char ad7746_vt_filter_rate_table[][2] = {
208 {50, 20 + 1}, {31, 32 + 1}, {16, 62 + 1}, {8, 122 + 1},
209 };
210
211 static const unsigned char ad7746_cap_filter_rate_table[][2] = {
212 {91, 11 + 1}, {84, 12 + 1}, {50, 20 + 1}, {26, 38 + 1},
213 {16, 62 + 1}, {13, 77 + 1}, {11, 92 + 1}, {9, 110 + 1},
214 };
215
ad7746_select_channel(struct iio_dev * indio_dev,struct iio_chan_spec const * chan)216 static int ad7746_select_channel(struct iio_dev *indio_dev,
217 struct iio_chan_spec const *chan)
218 {
219 struct ad7746_chip_info *chip = iio_priv(indio_dev);
220 int ret, delay;
221 u8 vt_setup, cap_setup;
222
223 switch (chan->type) {
224 case IIO_CAPACITANCE:
225 cap_setup = (chan->address & 0xFF) | AD7746_CAPSETUP_CAPEN;
226 vt_setup = chip->vt_setup & ~AD7746_VTSETUP_VTEN;
227 delay = ad7746_cap_filter_rate_table[(chip->config >> 3) &
228 0x7][1];
229
230 if (chip->capdac_set != chan->channel) {
231 ret = i2c_smbus_write_byte_data(chip->client,
232 AD7746_REG_CAPDACA,
233 chip->capdac[chan->channel][0]);
234 if (ret < 0)
235 return ret;
236 ret = i2c_smbus_write_byte_data(chip->client,
237 AD7746_REG_CAPDACB,
238 chip->capdac[chan->channel][1]);
239 if (ret < 0)
240 return ret;
241
242 chip->capdac_set = chan->channel;
243 }
244 break;
245 case IIO_VOLTAGE:
246 case IIO_TEMP:
247 vt_setup = (chan->address & 0xFF) | AD7746_VTSETUP_VTEN;
248 cap_setup = chip->cap_setup & ~AD7746_CAPSETUP_CAPEN;
249 delay = ad7746_cap_filter_rate_table[(chip->config >> 6) &
250 0x3][1];
251 break;
252 default:
253 return -EINVAL;
254 }
255
256 if (chip->cap_setup != cap_setup) {
257 ret = i2c_smbus_write_byte_data(chip->client,
258 AD7746_REG_CAP_SETUP,
259 cap_setup);
260 if (ret < 0)
261 return ret;
262
263 chip->cap_setup = cap_setup;
264 }
265
266 if (chip->vt_setup != vt_setup) {
267 ret = i2c_smbus_write_byte_data(chip->client,
268 AD7746_REG_VT_SETUP,
269 vt_setup);
270 if (ret < 0)
271 return ret;
272
273 chip->vt_setup = vt_setup;
274 }
275
276 return delay;
277 }
278
ad7746_start_calib(struct device * dev,struct device_attribute * attr,const char * buf,size_t len,u8 regval)279 static inline ssize_t ad7746_start_calib(struct device *dev,
280 struct device_attribute *attr,
281 const char *buf,
282 size_t len,
283 u8 regval)
284 {
285 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
286 struct ad7746_chip_info *chip = iio_priv(indio_dev);
287 bool doit;
288 int ret, timeout = 10;
289
290 ret = strtobool(buf, &doit);
291 if (ret < 0)
292 return ret;
293
294 if (!doit)
295 return 0;
296
297 mutex_lock(&indio_dev->mlock);
298 regval |= chip->config;
299 ret = i2c_smbus_write_byte_data(chip->client, AD7746_REG_CFG, regval);
300 if (ret < 0) {
301 mutex_unlock(&indio_dev->mlock);
302 return ret;
303 }
304
305 do {
306 msleep(20);
307 ret = i2c_smbus_read_byte_data(chip->client, AD7746_REG_CFG);
308 if (ret < 0) {
309 mutex_unlock(&indio_dev->mlock);
310 return ret;
311 }
312 } while ((ret == regval) && timeout--);
313
314 mutex_unlock(&indio_dev->mlock);
315
316 return len;
317 }
318
ad7746_start_offset_calib(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)319 static ssize_t ad7746_start_offset_calib(struct device *dev,
320 struct device_attribute *attr,
321 const char *buf,
322 size_t len)
323 {
324 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
325 int ret = ad7746_select_channel(indio_dev,
326 &ad7746_channels[to_iio_dev_attr(attr)->address]);
327 if (ret < 0)
328 return ret;
329
330 return ad7746_start_calib(dev, attr, buf, len,
331 AD7746_CONF_MODE_OFFS_CAL);
332 }
333
ad7746_start_gain_calib(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)334 static ssize_t ad7746_start_gain_calib(struct device *dev,
335 struct device_attribute *attr,
336 const char *buf,
337 size_t len)
338 {
339 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
340 int ret = ad7746_select_channel(indio_dev,
341 &ad7746_channels[to_iio_dev_attr(attr)->address]);
342 if (ret < 0)
343 return ret;
344
345 return ad7746_start_calib(dev, attr, buf, len,
346 AD7746_CONF_MODE_GAIN_CAL);
347 }
348
349 static IIO_DEVICE_ATTR(in_capacitance0_calibbias_calibration,
350 S_IWUSR, NULL, ad7746_start_offset_calib, CIN1);
351 static IIO_DEVICE_ATTR(in_capacitance1_calibbias_calibration,
352 S_IWUSR, NULL, ad7746_start_offset_calib, CIN2);
353 static IIO_DEVICE_ATTR(in_capacitance0_calibscale_calibration,
354 S_IWUSR, NULL, ad7746_start_gain_calib, CIN1);
355 static IIO_DEVICE_ATTR(in_capacitance1_calibscale_calibration,
356 S_IWUSR, NULL, ad7746_start_gain_calib, CIN2);
357 static IIO_DEVICE_ATTR(in_voltage0_calibscale_calibration,
358 S_IWUSR, NULL, ad7746_start_gain_calib, VIN);
359
ad7746_show_cap_filter_rate_setup(struct device * dev,struct device_attribute * attr,char * buf)360 static ssize_t ad7746_show_cap_filter_rate_setup(struct device *dev,
361 struct device_attribute *attr,
362 char *buf)
363 {
364 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
365 struct ad7746_chip_info *chip = iio_priv(indio_dev);
366
367 return sprintf(buf, "%d\n", ad7746_cap_filter_rate_table[
368 (chip->config >> 3) & 0x7][0]);
369 }
370
ad7746_store_cap_filter_rate_setup(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)371 static ssize_t ad7746_store_cap_filter_rate_setup(struct device *dev,
372 struct device_attribute *attr,
373 const char *buf,
374 size_t len)
375 {
376 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
377 struct ad7746_chip_info *chip = iio_priv(indio_dev);
378 u8 data;
379 int ret, i;
380
381 ret = kstrtou8(buf, 10, &data);
382 if (ret < 0)
383 return ret;
384
385 for (i = 0; i < ARRAY_SIZE(ad7746_cap_filter_rate_table); i++)
386 if (data >= ad7746_cap_filter_rate_table[i][0])
387 break;
388
389 if (i >= ARRAY_SIZE(ad7746_cap_filter_rate_table))
390 i = ARRAY_SIZE(ad7746_cap_filter_rate_table) - 1;
391
392 mutex_lock(&indio_dev->mlock);
393 chip->config &= ~AD7746_CONF_CAPFS(0x7);
394 chip->config |= AD7746_CONF_CAPFS(i);
395 mutex_unlock(&indio_dev->mlock);
396
397 return len;
398 }
399
ad7746_show_vt_filter_rate_setup(struct device * dev,struct device_attribute * attr,char * buf)400 static ssize_t ad7746_show_vt_filter_rate_setup(struct device *dev,
401 struct device_attribute *attr,
402 char *buf)
403 {
404 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
405 struct ad7746_chip_info *chip = iio_priv(indio_dev);
406
407 return sprintf(buf, "%d\n", ad7746_vt_filter_rate_table[
408 (chip->config >> 6) & 0x3][0]);
409 }
410
ad7746_store_vt_filter_rate_setup(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)411 static ssize_t ad7746_store_vt_filter_rate_setup(struct device *dev,
412 struct device_attribute *attr,
413 const char *buf,
414 size_t len)
415 {
416 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
417 struct ad7746_chip_info *chip = iio_priv(indio_dev);
418 u8 data;
419 int ret, i;
420
421 ret = kstrtou8(buf, 10, &data);
422 if (ret < 0)
423 return ret;
424
425 for (i = 0; i < ARRAY_SIZE(ad7746_vt_filter_rate_table); i++)
426 if (data >= ad7746_vt_filter_rate_table[i][0])
427 break;
428
429 if (i >= ARRAY_SIZE(ad7746_vt_filter_rate_table))
430 i = ARRAY_SIZE(ad7746_vt_filter_rate_table) - 1;
431
432 mutex_lock(&indio_dev->mlock);
433 chip->config &= ~AD7746_CONF_VTFS(0x3);
434 chip->config |= AD7746_CONF_VTFS(i);
435 mutex_unlock(&indio_dev->mlock);
436
437 return len;
438 }
439
440 static IIO_DEVICE_ATTR(in_capacitance_sampling_frequency,
441 S_IRUGO | S_IWUSR, ad7746_show_cap_filter_rate_setup,
442 ad7746_store_cap_filter_rate_setup, 0);
443
444 static IIO_DEVICE_ATTR(in_voltage_sampling_frequency,
445 S_IRUGO | S_IWUSR, ad7746_show_vt_filter_rate_setup,
446 ad7746_store_vt_filter_rate_setup, 0);
447
448 static IIO_CONST_ATTR(in_voltage_sampling_frequency_available, "50 31 16 8");
449 static IIO_CONST_ATTR(in_capacitance_sampling_frequency_available,
450 "91 84 50 26 16 13 11 9");
451
452 static struct attribute *ad7746_attributes[] = {
453 &iio_dev_attr_in_capacitance_sampling_frequency.dev_attr.attr,
454 &iio_dev_attr_in_voltage_sampling_frequency.dev_attr.attr,
455 &iio_dev_attr_in_capacitance0_calibbias_calibration.dev_attr.attr,
456 &iio_dev_attr_in_capacitance0_calibscale_calibration.dev_attr.attr,
457 &iio_dev_attr_in_capacitance1_calibscale_calibration.dev_attr.attr,
458 &iio_dev_attr_in_capacitance1_calibbias_calibration.dev_attr.attr,
459 &iio_dev_attr_in_voltage0_calibscale_calibration.dev_attr.attr,
460 &iio_const_attr_in_voltage_sampling_frequency_available.dev_attr.attr,
461 &iio_const_attr_in_capacitance_sampling_frequency_available.
462 dev_attr.attr,
463 NULL,
464 };
465
466 static const struct attribute_group ad7746_attribute_group = {
467 .attrs = ad7746_attributes,
468 };
469
ad7746_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)470 static int ad7746_write_raw(struct iio_dev *indio_dev,
471 struct iio_chan_spec const *chan,
472 int val,
473 int val2,
474 long mask)
475 {
476 struct ad7746_chip_info *chip = iio_priv(indio_dev);
477 int ret, reg;
478
479 mutex_lock(&indio_dev->mlock);
480
481 switch (mask) {
482 case IIO_CHAN_INFO_CALIBSCALE:
483 if (val != 1) {
484 ret = -EINVAL;
485 goto out;
486 }
487
488 val = (val2 * 1024) / 15625;
489
490 switch (chan->type) {
491 case IIO_CAPACITANCE:
492 reg = AD7746_REG_CAP_GAINH;
493 break;
494 case IIO_VOLTAGE:
495 reg = AD7746_REG_VOLT_GAINH;
496 break;
497 default:
498 ret = -EINVAL;
499 goto out;
500 }
501
502 ret = i2c_smbus_write_word_data(chip->client, reg, swab16(val));
503 if (ret < 0)
504 goto out;
505
506 ret = 0;
507 break;
508 case IIO_CHAN_INFO_CALIBBIAS:
509 if ((val < 0) | (val > 0xFFFF)) {
510 ret = -EINVAL;
511 goto out;
512 }
513 ret = i2c_smbus_write_word_data(chip->client,
514 AD7746_REG_CAP_OFFH, swab16(val));
515 if (ret < 0)
516 goto out;
517
518 ret = 0;
519 break;
520 case IIO_CHAN_INFO_OFFSET:
521 if ((val < 0) | (val > 43008000)) { /* 21pF */
522 ret = -EINVAL;
523 goto out;
524 }
525
526 /* CAPDAC Scale = 21pF_typ / 127
527 * CIN Scale = 8.192pF / 2^24
528 * Offset Scale = CAPDAC Scale / CIN Scale = 338646
529 * */
530
531 val /= 338646;
532
533 chip->capdac[chan->channel][chan->differential] = (val > 0 ?
534 AD7746_CAPDAC_DACP(val) | AD7746_CAPDAC_DACEN : 0);
535
536 ret = i2c_smbus_write_byte_data(chip->client,
537 AD7746_REG_CAPDACA,
538 chip->capdac[chan->channel][0]);
539 if (ret < 0)
540 goto out;
541 ret = i2c_smbus_write_byte_data(chip->client,
542 AD7746_REG_CAPDACB,
543 chip->capdac[chan->channel][1]);
544 if (ret < 0)
545 goto out;
546
547 chip->capdac_set = chan->channel;
548
549 ret = 0;
550 break;
551 default:
552 ret = -EINVAL;
553 }
554
555 out:
556 mutex_unlock(&indio_dev->mlock);
557 return ret;
558 }
559
ad7746_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)560 static int ad7746_read_raw(struct iio_dev *indio_dev,
561 struct iio_chan_spec const *chan,
562 int *val, int *val2,
563 long mask)
564 {
565 struct ad7746_chip_info *chip = iio_priv(indio_dev);
566 int ret, delay;
567 u8 regval, reg;
568
569 union {
570 u32 d32;
571 u8 d8[4];
572 } data;
573
574 mutex_lock(&indio_dev->mlock);
575
576 switch (mask) {
577 case IIO_CHAN_INFO_RAW:
578 case IIO_CHAN_INFO_PROCESSED:
579 ret = ad7746_select_channel(indio_dev, chan);
580 if (ret < 0)
581 goto out;
582 delay = ret;
583
584 regval = chip->config | AD7746_CONF_MODE_SINGLE_CONV;
585 ret = i2c_smbus_write_byte_data(chip->client, AD7746_REG_CFG,
586 regval);
587 if (ret < 0)
588 goto out;
589
590 msleep(delay);
591 /* Now read the actual register */
592
593 ret = i2c_smbus_read_i2c_block_data(chip->client,
594 chan->address >> 8, 3, &data.d8[1]);
595
596 if (ret < 0)
597 goto out;
598
599 *val = (be32_to_cpu(data.d32) & 0xFFFFFF) - 0x800000;
600
601 switch (chan->type) {
602 case IIO_TEMP:
603 /* temperature in milli degrees Celsius
604 * T = ((*val / 2048) - 4096) * 1000
605 */
606 *val = (*val * 125) / 256;
607 break;
608 case IIO_VOLTAGE:
609 if (chan->channel == 1) /* supply_raw*/
610 *val = *val * 6;
611 break;
612 default:
613 break;
614 }
615
616 ret = IIO_VAL_INT;
617 break;
618 case IIO_CHAN_INFO_CALIBSCALE:
619 switch (chan->type) {
620 case IIO_CAPACITANCE:
621 reg = AD7746_REG_CAP_GAINH;
622 break;
623 case IIO_VOLTAGE:
624 reg = AD7746_REG_VOLT_GAINH;
625 break;
626 default:
627 ret = -EINVAL;
628 goto out;
629 }
630
631 ret = i2c_smbus_read_word_data(chip->client, reg);
632 if (ret < 0)
633 goto out;
634 /* 1 + gain_val / 2^16 */
635 *val = 1;
636 *val2 = (15625 * swab16(ret)) / 1024;
637
638 ret = IIO_VAL_INT_PLUS_MICRO;
639 break;
640 case IIO_CHAN_INFO_CALIBBIAS:
641 ret = i2c_smbus_read_word_data(chip->client,
642 AD7746_REG_CAP_OFFH);
643 if (ret < 0)
644 goto out;
645 *val = swab16(ret);
646
647 ret = IIO_VAL_INT;
648 break;
649 case IIO_CHAN_INFO_OFFSET:
650 *val = AD7746_CAPDAC_DACP(chip->capdac[chan->channel]
651 [chan->differential]) * 338646;
652
653 ret = IIO_VAL_INT;
654 break;
655 case IIO_CHAN_INFO_SCALE:
656 switch (chan->type) {
657 case IIO_CAPACITANCE:
658 /* 8.192pf / 2^24 */
659 *val2 = 488;
660 *val = 0;
661 break;
662 case IIO_VOLTAGE:
663 /* 1170mV / 2^23 */
664 *val2 = 139475;
665 *val = 0;
666 break;
667 default:
668 ret = -EINVAL;
669 goto out;
670 }
671
672 ret = IIO_VAL_INT_PLUS_NANO;
673 break;
674 default:
675 ret = -EINVAL;
676 }
677 out:
678 mutex_unlock(&indio_dev->mlock);
679 return ret;
680 }
681
682 static const struct iio_info ad7746_info = {
683 .attrs = &ad7746_attribute_group,
684 .read_raw = &ad7746_read_raw,
685 .write_raw = &ad7746_write_raw,
686 .driver_module = THIS_MODULE,
687 };
688
689 /*
690 * device probe and remove
691 */
692
ad7746_probe(struct i2c_client * client,const struct i2c_device_id * id)693 static int ad7746_probe(struct i2c_client *client,
694 const struct i2c_device_id *id)
695 {
696 struct ad7746_platform_data *pdata = client->dev.platform_data;
697 struct ad7746_chip_info *chip;
698 struct iio_dev *indio_dev;
699 int ret = 0;
700 unsigned char regval = 0;
701
702 indio_dev = iio_device_alloc(sizeof(*chip));
703 if (indio_dev == NULL) {
704 ret = -ENOMEM;
705 goto error_ret;
706 }
707 chip = iio_priv(indio_dev);
708 /* this is only used for device removal purposes */
709 i2c_set_clientdata(client, indio_dev);
710
711 chip->client = client;
712 chip->capdac_set = -1;
713
714 /* Establish that the iio_dev is a child of the i2c device */
715 indio_dev->name = id->name;
716 indio_dev->dev.parent = &client->dev;
717 indio_dev->info = &ad7746_info;
718 indio_dev->channels = ad7746_channels;
719 if (id->driver_data == 7746)
720 indio_dev->num_channels = ARRAY_SIZE(ad7746_channels);
721 else
722 indio_dev->num_channels = ARRAY_SIZE(ad7746_channels) - 2;
723 indio_dev->num_channels = ARRAY_SIZE(ad7746_channels);
724 indio_dev->modes = INDIO_DIRECT_MODE;
725
726 if (pdata) {
727 if (pdata->exca_en) {
728 if (pdata->exca_inv_en)
729 regval |= AD7746_EXCSETUP_NEXCA;
730 else
731 regval |= AD7746_EXCSETUP_EXCA;
732 }
733
734 if (pdata->excb_en) {
735 if (pdata->excb_inv_en)
736 regval |= AD7746_EXCSETUP_NEXCB;
737 else
738 regval |= AD7746_EXCSETUP_EXCB;
739 }
740
741 regval |= AD7746_EXCSETUP_EXCLVL(pdata->exclvl);
742 } else {
743 dev_warn(&client->dev, "No platform data? using default\n");
744 regval = AD7746_EXCSETUP_EXCA | AD7746_EXCSETUP_EXCB |
745 AD7746_EXCSETUP_EXCLVL(3);
746 }
747
748 ret = i2c_smbus_write_byte_data(chip->client,
749 AD7746_REG_EXC_SETUP, regval);
750 if (ret < 0)
751 goto error_free_dev;
752
753 ret = iio_device_register(indio_dev);
754 if (ret)
755 goto error_free_dev;
756
757 dev_info(&client->dev, "%s capacitive sensor registered\n", id->name);
758
759 return 0;
760
761 error_free_dev:
762 iio_device_free(indio_dev);
763 error_ret:
764 return ret;
765 }
766
ad7746_remove(struct i2c_client * client)767 static int ad7746_remove(struct i2c_client *client)
768 {
769 struct iio_dev *indio_dev = i2c_get_clientdata(client);
770
771 iio_device_unregister(indio_dev);
772 iio_device_free(indio_dev);
773
774 return 0;
775 }
776
777 static const struct i2c_device_id ad7746_id[] = {
778 { "ad7745", 7745 },
779 { "ad7746", 7746 },
780 { "ad7747", 7747 },
781 {}
782 };
783
784 MODULE_DEVICE_TABLE(i2c, ad7746_id);
785
786 static struct i2c_driver ad7746_driver = {
787 .driver = {
788 .name = KBUILD_MODNAME,
789 },
790 .probe = ad7746_probe,
791 .remove = ad7746_remove,
792 .id_table = ad7746_id,
793 };
794 module_i2c_driver(ad7746_driver);
795
796 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
797 MODULE_DESCRIPTION("Analog Devices AD7746/5/7 capacitive sensor driver");
798 MODULE_LICENSE("GPL v2");
799