1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * ad2s1210.c support for the ADI Resolver to Digital Converters: AD2S1210
4 *
5 * Copyright (c) 2010-2010 Analog Devices Inc.
6 */
7 #include <linux/types.h>
8 #include <linux/mutex.h>
9 #include <linux/device.h>
10 #include <linux/spi/spi.h>
11 #include <linux/slab.h>
12 #include <linux/sysfs.h>
13 #include <linux/delay.h>
14 #include <linux/gpio/consumer.h>
15 #include <linux/module.h>
16
17 #include <linux/iio/iio.h>
18 #include <linux/iio/sysfs.h>
19
20 #define DRV_NAME "ad2s1210"
21
22 #define AD2S1210_DEF_CONTROL 0x7E
23
24 #define AD2S1210_MSB_IS_HIGH 0x80
25 #define AD2S1210_MSB_IS_LOW 0x7F
26 #define AD2S1210_PHASE_LOCK_RANGE_44 0x20
27 #define AD2S1210_ENABLE_HYSTERESIS 0x10
28 #define AD2S1210_SET_ENRES1 0x08
29 #define AD2S1210_SET_ENRES0 0x04
30 #define AD2S1210_SET_RES1 0x02
31 #define AD2S1210_SET_RES0 0x01
32
33 #define AD2S1210_SET_RESOLUTION (AD2S1210_SET_RES1 | AD2S1210_SET_RES0)
34
35 #define AD2S1210_REG_POSITION 0x80
36 #define AD2S1210_REG_VELOCITY 0x82
37 #define AD2S1210_REG_LOS_THRD 0x88
38 #define AD2S1210_REG_DOS_OVR_THRD 0x89
39 #define AD2S1210_REG_DOS_MIS_THRD 0x8A
40 #define AD2S1210_REG_DOS_RST_MAX_THRD 0x8B
41 #define AD2S1210_REG_DOS_RST_MIN_THRD 0x8C
42 #define AD2S1210_REG_LOT_HIGH_THRD 0x8D
43 #define AD2S1210_REG_LOT_LOW_THRD 0x8E
44 #define AD2S1210_REG_EXCIT_FREQ 0x91
45 #define AD2S1210_REG_CONTROL 0x92
46 #define AD2S1210_REG_SOFT_RESET 0xF0
47 #define AD2S1210_REG_FAULT 0xFF
48
49 #define AD2S1210_MIN_CLKIN 6144000
50 #define AD2S1210_MAX_CLKIN 10240000
51 #define AD2S1210_MIN_EXCIT 2000
52 #define AD2S1210_MAX_EXCIT 20000
53 #define AD2S1210_MIN_FCW 0x4
54 #define AD2S1210_MAX_FCW 0x50
55
56 #define AD2S1210_DEF_EXCIT 10000
57
58 enum ad2s1210_mode {
59 MOD_POS = 0,
60 MOD_VEL,
61 MOD_CONFIG,
62 MOD_RESERVED,
63 };
64
65 enum ad2s1210_gpios {
66 AD2S1210_SAMPLE,
67 AD2S1210_A0,
68 AD2S1210_A1,
69 AD2S1210_RES0,
70 AD2S1210_RES1,
71 };
72
73 struct ad2s1210_gpio {
74 const char *name;
75 unsigned long flags;
76 };
77
78 static const struct ad2s1210_gpio gpios[] = {
79 [AD2S1210_SAMPLE] = { .name = "adi,sample", .flags = GPIOD_OUT_LOW },
80 [AD2S1210_A0] = { .name = "adi,a0", .flags = GPIOD_OUT_LOW },
81 [AD2S1210_A1] = { .name = "adi,a1", .flags = GPIOD_OUT_LOW },
82 [AD2S1210_RES0] = { .name = "adi,res0", .flags = GPIOD_OUT_LOW },
83 [AD2S1210_RES1] = { .name = "adi,res1", .flags = GPIOD_OUT_LOW },
84 };
85
86 static const unsigned int ad2s1210_resolution_value[] = { 10, 12, 14, 16 };
87
88 struct ad2s1210_state {
89 struct mutex lock;
90 struct spi_device *sdev;
91 struct gpio_desc *gpios[5];
92 unsigned int fclkin;
93 unsigned int fexcit;
94 bool hysteresis;
95 u8 resolution;
96 enum ad2s1210_mode mode;
97 u8 rx[2] ____cacheline_aligned;
98 u8 tx[2] ____cacheline_aligned;
99 };
100
101 static const int ad2s1210_mode_vals[4][2] = {
102 [MOD_POS] = { 0, 0 },
103 [MOD_VEL] = { 0, 1 },
104 [MOD_CONFIG] = { 1, 0 },
105 };
106
ad2s1210_set_mode(enum ad2s1210_mode mode,struct ad2s1210_state * st)107 static inline void ad2s1210_set_mode(enum ad2s1210_mode mode,
108 struct ad2s1210_state *st)
109 {
110 gpiod_set_value(st->gpios[AD2S1210_A0], ad2s1210_mode_vals[mode][0]);
111 gpiod_set_value(st->gpios[AD2S1210_A1], ad2s1210_mode_vals[mode][1]);
112 st->mode = mode;
113 }
114
115 /* write 1 bytes (address or data) to the chip */
ad2s1210_config_write(struct ad2s1210_state * st,u8 data)116 static int ad2s1210_config_write(struct ad2s1210_state *st, u8 data)
117 {
118 int ret;
119
120 ad2s1210_set_mode(MOD_CONFIG, st);
121 st->tx[0] = data;
122 ret = spi_write(st->sdev, st->tx, 1);
123 if (ret < 0)
124 return ret;
125
126 return 0;
127 }
128
129 /* read value from one of the registers */
ad2s1210_config_read(struct ad2s1210_state * st,unsigned char address)130 static int ad2s1210_config_read(struct ad2s1210_state *st,
131 unsigned char address)
132 {
133 struct spi_transfer xfers[] = {
134 {
135 .len = 1,
136 .rx_buf = &st->rx[0],
137 .tx_buf = &st->tx[0],
138 .cs_change = 1,
139 }, {
140 .len = 1,
141 .rx_buf = &st->rx[1],
142 .tx_buf = &st->tx[1],
143 },
144 };
145 int ret = 0;
146
147 ad2s1210_set_mode(MOD_CONFIG, st);
148 st->tx[0] = address | AD2S1210_MSB_IS_HIGH;
149 st->tx[1] = AD2S1210_REG_FAULT;
150 ret = spi_sync_transfer(st->sdev, xfers, 2);
151 if (ret < 0)
152 return ret;
153
154 return st->rx[1];
155 }
156
157 static inline
ad2s1210_update_frequency_control_word(struct ad2s1210_state * st)158 int ad2s1210_update_frequency_control_word(struct ad2s1210_state *st)
159 {
160 int ret;
161 unsigned char fcw;
162
163 fcw = (unsigned char)(st->fexcit * (1 << 15) / st->fclkin);
164 if (fcw < AD2S1210_MIN_FCW || fcw > AD2S1210_MAX_FCW) {
165 dev_err(&st->sdev->dev, "ad2s1210: FCW out of range\n");
166 return -ERANGE;
167 }
168
169 ret = ad2s1210_config_write(st, AD2S1210_REG_EXCIT_FREQ);
170 if (ret < 0)
171 return ret;
172
173 return ad2s1210_config_write(st, fcw);
174 }
175
176 static const int ad2s1210_res_pins[4][2] = {
177 { 0, 0 }, {0, 1}, {1, 0}, {1, 1}
178 };
179
ad2s1210_set_resolution_pin(struct ad2s1210_state * st)180 static inline void ad2s1210_set_resolution_pin(struct ad2s1210_state *st)
181 {
182 gpiod_set_value(st->gpios[AD2S1210_RES0],
183 ad2s1210_res_pins[(st->resolution - 10) / 2][0]);
184 gpiod_set_value(st->gpios[AD2S1210_RES1],
185 ad2s1210_res_pins[(st->resolution - 10) / 2][1]);
186 }
187
ad2s1210_soft_reset(struct ad2s1210_state * st)188 static inline int ad2s1210_soft_reset(struct ad2s1210_state *st)
189 {
190 int ret;
191
192 ret = ad2s1210_config_write(st, AD2S1210_REG_SOFT_RESET);
193 if (ret < 0)
194 return ret;
195
196 return ad2s1210_config_write(st, 0x0);
197 }
198
ad2s1210_show_fclkin(struct device * dev,struct device_attribute * attr,char * buf)199 static ssize_t ad2s1210_show_fclkin(struct device *dev,
200 struct device_attribute *attr,
201 char *buf)
202 {
203 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
204
205 return sprintf(buf, "%u\n", st->fclkin);
206 }
207
ad2s1210_store_fclkin(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)208 static ssize_t ad2s1210_store_fclkin(struct device *dev,
209 struct device_attribute *attr,
210 const char *buf,
211 size_t len)
212 {
213 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
214 unsigned int fclkin;
215 int ret;
216
217 ret = kstrtouint(buf, 10, &fclkin);
218 if (ret)
219 return ret;
220 if (fclkin < AD2S1210_MIN_CLKIN || fclkin > AD2S1210_MAX_CLKIN) {
221 dev_err(dev, "ad2s1210: fclkin out of range\n");
222 return -EINVAL;
223 }
224
225 mutex_lock(&st->lock);
226 st->fclkin = fclkin;
227
228 ret = ad2s1210_update_frequency_control_word(st);
229 if (ret < 0)
230 goto error_ret;
231 ret = ad2s1210_soft_reset(st);
232 error_ret:
233 mutex_unlock(&st->lock);
234
235 return ret < 0 ? ret : len;
236 }
237
ad2s1210_show_fexcit(struct device * dev,struct device_attribute * attr,char * buf)238 static ssize_t ad2s1210_show_fexcit(struct device *dev,
239 struct device_attribute *attr,
240 char *buf)
241 {
242 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
243
244 return sprintf(buf, "%u\n", st->fexcit);
245 }
246
ad2s1210_store_fexcit(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)247 static ssize_t ad2s1210_store_fexcit(struct device *dev,
248 struct device_attribute *attr,
249 const char *buf, size_t len)
250 {
251 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
252 unsigned int fexcit;
253 int ret;
254
255 ret = kstrtouint(buf, 10, &fexcit);
256 if (ret < 0)
257 return ret;
258 if (fexcit < AD2S1210_MIN_EXCIT || fexcit > AD2S1210_MAX_EXCIT) {
259 dev_err(dev,
260 "ad2s1210: excitation frequency out of range\n");
261 return -EINVAL;
262 }
263 mutex_lock(&st->lock);
264 st->fexcit = fexcit;
265 ret = ad2s1210_update_frequency_control_word(st);
266 if (ret < 0)
267 goto error_ret;
268 ret = ad2s1210_soft_reset(st);
269 error_ret:
270 mutex_unlock(&st->lock);
271
272 return ret < 0 ? ret : len;
273 }
274
ad2s1210_show_control(struct device * dev,struct device_attribute * attr,char * buf)275 static ssize_t ad2s1210_show_control(struct device *dev,
276 struct device_attribute *attr,
277 char *buf)
278 {
279 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
280 int ret;
281
282 mutex_lock(&st->lock);
283 ret = ad2s1210_config_read(st, AD2S1210_REG_CONTROL);
284 mutex_unlock(&st->lock);
285 return ret < 0 ? ret : sprintf(buf, "0x%x\n", ret);
286 }
287
ad2s1210_store_control(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)288 static ssize_t ad2s1210_store_control(struct device *dev,
289 struct device_attribute *attr,
290 const char *buf, size_t len)
291 {
292 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
293 unsigned char udata;
294 unsigned char data;
295 int ret;
296
297 ret = kstrtou8(buf, 16, &udata);
298 if (ret)
299 return -EINVAL;
300
301 mutex_lock(&st->lock);
302 ret = ad2s1210_config_write(st, AD2S1210_REG_CONTROL);
303 if (ret < 0)
304 goto error_ret;
305 data = udata & AD2S1210_MSB_IS_LOW;
306 ret = ad2s1210_config_write(st, data);
307 if (ret < 0)
308 goto error_ret;
309
310 ret = ad2s1210_config_read(st, AD2S1210_REG_CONTROL);
311 if (ret < 0)
312 goto error_ret;
313 if (ret & AD2S1210_MSB_IS_HIGH) {
314 ret = -EIO;
315 dev_err(dev,
316 "ad2s1210: write control register fail\n");
317 goto error_ret;
318 }
319 st->resolution =
320 ad2s1210_resolution_value[data & AD2S1210_SET_RESOLUTION];
321 ad2s1210_set_resolution_pin(st);
322 ret = len;
323 st->hysteresis = !!(data & AD2S1210_ENABLE_HYSTERESIS);
324
325 error_ret:
326 mutex_unlock(&st->lock);
327 return ret;
328 }
329
ad2s1210_show_resolution(struct device * dev,struct device_attribute * attr,char * buf)330 static ssize_t ad2s1210_show_resolution(struct device *dev,
331 struct device_attribute *attr,
332 char *buf)
333 {
334 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
335
336 return sprintf(buf, "%d\n", st->resolution);
337 }
338
ad2s1210_store_resolution(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)339 static ssize_t ad2s1210_store_resolution(struct device *dev,
340 struct device_attribute *attr,
341 const char *buf, size_t len)
342 {
343 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
344 unsigned char data;
345 unsigned char udata;
346 int ret;
347
348 ret = kstrtou8(buf, 10, &udata);
349 if (ret || udata < 10 || udata > 16) {
350 dev_err(dev, "ad2s1210: resolution out of range\n");
351 return -EINVAL;
352 }
353 mutex_lock(&st->lock);
354 ret = ad2s1210_config_read(st, AD2S1210_REG_CONTROL);
355 if (ret < 0)
356 goto error_ret;
357 data = ret;
358 data &= ~AD2S1210_SET_RESOLUTION;
359 data |= (udata - 10) >> 1;
360 ret = ad2s1210_config_write(st, AD2S1210_REG_CONTROL);
361 if (ret < 0)
362 goto error_ret;
363 ret = ad2s1210_config_write(st, data & AD2S1210_MSB_IS_LOW);
364 if (ret < 0)
365 goto error_ret;
366 ret = ad2s1210_config_read(st, AD2S1210_REG_CONTROL);
367 if (ret < 0)
368 goto error_ret;
369 data = ret;
370 if (data & AD2S1210_MSB_IS_HIGH) {
371 ret = -EIO;
372 dev_err(dev, "ad2s1210: setting resolution fail\n");
373 goto error_ret;
374 }
375 st->resolution =
376 ad2s1210_resolution_value[data & AD2S1210_SET_RESOLUTION];
377 ad2s1210_set_resolution_pin(st);
378 ret = len;
379 error_ret:
380 mutex_unlock(&st->lock);
381 return ret;
382 }
383
384 /* read the fault register since last sample */
ad2s1210_show_fault(struct device * dev,struct device_attribute * attr,char * buf)385 static ssize_t ad2s1210_show_fault(struct device *dev,
386 struct device_attribute *attr, char *buf)
387 {
388 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
389 int ret;
390
391 mutex_lock(&st->lock);
392 ret = ad2s1210_config_read(st, AD2S1210_REG_FAULT);
393 mutex_unlock(&st->lock);
394
395 return ret ? ret : sprintf(buf, "0x%x\n", ret);
396 }
397
ad2s1210_clear_fault(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)398 static ssize_t ad2s1210_clear_fault(struct device *dev,
399 struct device_attribute *attr,
400 const char *buf,
401 size_t len)
402 {
403 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
404 int ret;
405
406 mutex_lock(&st->lock);
407 gpiod_set_value(st->gpios[AD2S1210_SAMPLE], 0);
408 /* delay (2 * tck + 20) nano seconds */
409 udelay(1);
410 gpiod_set_value(st->gpios[AD2S1210_SAMPLE], 1);
411 ret = ad2s1210_config_read(st, AD2S1210_REG_FAULT);
412 if (ret < 0)
413 goto error_ret;
414 gpiod_set_value(st->gpios[AD2S1210_SAMPLE], 0);
415 gpiod_set_value(st->gpios[AD2S1210_SAMPLE], 1);
416 error_ret:
417 mutex_unlock(&st->lock);
418
419 return ret < 0 ? ret : len;
420 }
421
ad2s1210_show_reg(struct device * dev,struct device_attribute * attr,char * buf)422 static ssize_t ad2s1210_show_reg(struct device *dev,
423 struct device_attribute *attr,
424 char *buf)
425 {
426 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
427 struct iio_dev_attr *iattr = to_iio_dev_attr(attr);
428 int ret;
429
430 mutex_lock(&st->lock);
431 ret = ad2s1210_config_read(st, iattr->address);
432 mutex_unlock(&st->lock);
433
434 return ret < 0 ? ret : sprintf(buf, "%d\n", ret);
435 }
436
ad2s1210_store_reg(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)437 static ssize_t ad2s1210_store_reg(struct device *dev,
438 struct device_attribute *attr,
439 const char *buf, size_t len)
440 {
441 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
442 unsigned char data;
443 int ret;
444 struct iio_dev_attr *iattr = to_iio_dev_attr(attr);
445
446 ret = kstrtou8(buf, 10, &data);
447 if (ret)
448 return -EINVAL;
449 mutex_lock(&st->lock);
450 ret = ad2s1210_config_write(st, iattr->address);
451 if (ret < 0)
452 goto error_ret;
453 ret = ad2s1210_config_write(st, data & AD2S1210_MSB_IS_LOW);
454 error_ret:
455 mutex_unlock(&st->lock);
456 return ret < 0 ? ret : len;
457 }
458
ad2s1210_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long m)459 static int ad2s1210_read_raw(struct iio_dev *indio_dev,
460 struct iio_chan_spec const *chan,
461 int *val,
462 int *val2,
463 long m)
464 {
465 struct ad2s1210_state *st = iio_priv(indio_dev);
466 u16 negative;
467 int ret = 0;
468 u16 pos;
469 s16 vel;
470
471 mutex_lock(&st->lock);
472 gpiod_set_value(st->gpios[AD2S1210_SAMPLE], 0);
473 /* delay (6 * tck + 20) nano seconds */
474 udelay(1);
475
476 switch (chan->type) {
477 case IIO_ANGL:
478 ad2s1210_set_mode(MOD_POS, st);
479 break;
480 case IIO_ANGL_VEL:
481 ad2s1210_set_mode(MOD_VEL, st);
482 break;
483 default:
484 ret = -EINVAL;
485 break;
486 }
487 if (ret < 0)
488 goto error_ret;
489 ret = spi_read(st->sdev, st->rx, 2);
490 if (ret < 0)
491 goto error_ret;
492
493 switch (chan->type) {
494 case IIO_ANGL:
495 pos = be16_to_cpup((__be16 *)st->rx);
496 if (st->hysteresis)
497 pos >>= 16 - st->resolution;
498 *val = pos;
499 ret = IIO_VAL_INT;
500 break;
501 case IIO_ANGL_VEL:
502 vel = be16_to_cpup((__be16 *)st->rx);
503 vel >>= 16 - st->resolution;
504 if (vel & 0x8000) {
505 negative = (0xffff >> st->resolution) << st->resolution;
506 vel |= negative;
507 }
508 *val = vel;
509 ret = IIO_VAL_INT;
510 break;
511 default:
512 mutex_unlock(&st->lock);
513 return -EINVAL;
514 }
515
516 error_ret:
517 gpiod_set_value(st->gpios[AD2S1210_SAMPLE], 1);
518 /* delay (2 * tck + 20) nano seconds */
519 udelay(1);
520 mutex_unlock(&st->lock);
521 return ret;
522 }
523
524 static IIO_DEVICE_ATTR(fclkin, 0644,
525 ad2s1210_show_fclkin, ad2s1210_store_fclkin, 0);
526 static IIO_DEVICE_ATTR(fexcit, 0644,
527 ad2s1210_show_fexcit, ad2s1210_store_fexcit, 0);
528 static IIO_DEVICE_ATTR(control, 0644,
529 ad2s1210_show_control, ad2s1210_store_control, 0);
530 static IIO_DEVICE_ATTR(bits, 0644,
531 ad2s1210_show_resolution, ad2s1210_store_resolution, 0);
532 static IIO_DEVICE_ATTR(fault, 0644,
533 ad2s1210_show_fault, ad2s1210_clear_fault, 0);
534
535 static IIO_DEVICE_ATTR(los_thrd, 0644,
536 ad2s1210_show_reg, ad2s1210_store_reg,
537 AD2S1210_REG_LOS_THRD);
538 static IIO_DEVICE_ATTR(dos_ovr_thrd, 0644,
539 ad2s1210_show_reg, ad2s1210_store_reg,
540 AD2S1210_REG_DOS_OVR_THRD);
541 static IIO_DEVICE_ATTR(dos_mis_thrd, 0644,
542 ad2s1210_show_reg, ad2s1210_store_reg,
543 AD2S1210_REG_DOS_MIS_THRD);
544 static IIO_DEVICE_ATTR(dos_rst_max_thrd, 0644,
545 ad2s1210_show_reg, ad2s1210_store_reg,
546 AD2S1210_REG_DOS_RST_MAX_THRD);
547 static IIO_DEVICE_ATTR(dos_rst_min_thrd, 0644,
548 ad2s1210_show_reg, ad2s1210_store_reg,
549 AD2S1210_REG_DOS_RST_MIN_THRD);
550 static IIO_DEVICE_ATTR(lot_high_thrd, 0644,
551 ad2s1210_show_reg, ad2s1210_store_reg,
552 AD2S1210_REG_LOT_HIGH_THRD);
553 static IIO_DEVICE_ATTR(lot_low_thrd, 0644,
554 ad2s1210_show_reg, ad2s1210_store_reg,
555 AD2S1210_REG_LOT_LOW_THRD);
556
557 static const struct iio_chan_spec ad2s1210_channels[] = {
558 {
559 .type = IIO_ANGL,
560 .indexed = 1,
561 .channel = 0,
562 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
563 }, {
564 .type = IIO_ANGL_VEL,
565 .indexed = 1,
566 .channel = 0,
567 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
568 }
569 };
570
571 static struct attribute *ad2s1210_attributes[] = {
572 &iio_dev_attr_fclkin.dev_attr.attr,
573 &iio_dev_attr_fexcit.dev_attr.attr,
574 &iio_dev_attr_control.dev_attr.attr,
575 &iio_dev_attr_bits.dev_attr.attr,
576 &iio_dev_attr_fault.dev_attr.attr,
577 &iio_dev_attr_los_thrd.dev_attr.attr,
578 &iio_dev_attr_dos_ovr_thrd.dev_attr.attr,
579 &iio_dev_attr_dos_mis_thrd.dev_attr.attr,
580 &iio_dev_attr_dos_rst_max_thrd.dev_attr.attr,
581 &iio_dev_attr_dos_rst_min_thrd.dev_attr.attr,
582 &iio_dev_attr_lot_high_thrd.dev_attr.attr,
583 &iio_dev_attr_lot_low_thrd.dev_attr.attr,
584 NULL,
585 };
586
587 static const struct attribute_group ad2s1210_attribute_group = {
588 .attrs = ad2s1210_attributes,
589 };
590
ad2s1210_initial(struct ad2s1210_state * st)591 static int ad2s1210_initial(struct ad2s1210_state *st)
592 {
593 unsigned char data;
594 int ret;
595
596 mutex_lock(&st->lock);
597 ad2s1210_set_resolution_pin(st);
598
599 ret = ad2s1210_config_write(st, AD2S1210_REG_CONTROL);
600 if (ret < 0)
601 goto error_ret;
602 data = AD2S1210_DEF_CONTROL & ~(AD2S1210_SET_RESOLUTION);
603 data |= (st->resolution - 10) >> 1;
604 ret = ad2s1210_config_write(st, data);
605 if (ret < 0)
606 goto error_ret;
607 ret = ad2s1210_config_read(st, AD2S1210_REG_CONTROL);
608 if (ret < 0)
609 goto error_ret;
610
611 if (ret & AD2S1210_MSB_IS_HIGH) {
612 ret = -EIO;
613 goto error_ret;
614 }
615
616 ret = ad2s1210_update_frequency_control_word(st);
617 if (ret < 0)
618 goto error_ret;
619 ret = ad2s1210_soft_reset(st);
620 error_ret:
621 mutex_unlock(&st->lock);
622 return ret;
623 }
624
625 static const struct iio_info ad2s1210_info = {
626 .read_raw = ad2s1210_read_raw,
627 .attrs = &ad2s1210_attribute_group,
628 };
629
ad2s1210_setup_gpios(struct ad2s1210_state * st)630 static int ad2s1210_setup_gpios(struct ad2s1210_state *st)
631 {
632 struct spi_device *spi = st->sdev;
633 int i, ret;
634
635 for (i = 0; i < ARRAY_SIZE(gpios); i++) {
636 st->gpios[i] = devm_gpiod_get(&spi->dev, gpios[i].name,
637 gpios[i].flags);
638 if (IS_ERR(st->gpios[i])) {
639 ret = PTR_ERR(st->gpios[i]);
640 dev_err(&spi->dev,
641 "ad2s1210: failed to request %s GPIO: %d\n",
642 gpios[i].name, ret);
643 return ret;
644 }
645 }
646
647 return 0;
648 }
649
ad2s1210_probe(struct spi_device * spi)650 static int ad2s1210_probe(struct spi_device *spi)
651 {
652 struct iio_dev *indio_dev;
653 struct ad2s1210_state *st;
654 int ret;
655
656 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
657 if (!indio_dev)
658 return -ENOMEM;
659 st = iio_priv(indio_dev);
660 ret = ad2s1210_setup_gpios(st);
661 if (ret < 0)
662 return ret;
663
664 spi_set_drvdata(spi, indio_dev);
665
666 mutex_init(&st->lock);
667 st->sdev = spi;
668 st->hysteresis = true;
669 st->mode = MOD_CONFIG;
670 st->resolution = 12;
671 st->fexcit = AD2S1210_DEF_EXCIT;
672
673 indio_dev->info = &ad2s1210_info;
674 indio_dev->modes = INDIO_DIRECT_MODE;
675 indio_dev->channels = ad2s1210_channels;
676 indio_dev->num_channels = ARRAY_SIZE(ad2s1210_channels);
677 indio_dev->name = spi_get_device_id(spi)->name;
678
679 ret = devm_iio_device_register(&spi->dev, indio_dev);
680 if (ret)
681 return ret;
682
683 st->fclkin = spi->max_speed_hz;
684 spi->mode = SPI_MODE_3;
685 spi_setup(spi);
686 ad2s1210_initial(st);
687
688 return 0;
689 }
690
691 static const struct of_device_id ad2s1210_of_match[] = {
692 { .compatible = "adi,ad2s1210", },
693 { }
694 };
695 MODULE_DEVICE_TABLE(of, ad2s1210_of_match);
696
697 static const struct spi_device_id ad2s1210_id[] = {
698 { "ad2s1210" },
699 {}
700 };
701 MODULE_DEVICE_TABLE(spi, ad2s1210_id);
702
703 static struct spi_driver ad2s1210_driver = {
704 .driver = {
705 .name = DRV_NAME,
706 .of_match_table = of_match_ptr(ad2s1210_of_match),
707 },
708 .probe = ad2s1210_probe,
709 .id_table = ad2s1210_id,
710 };
711 module_spi_driver(ad2s1210_driver);
712
713 MODULE_AUTHOR("Graff Yang <graff.yang@gmail.com>");
714 MODULE_DESCRIPTION("Analog Devices AD2S1210 Resolver to Digital SPI driver");
715 MODULE_LICENSE("GPL v2");
716