1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * LTC2664 4 channel, 12-/16-Bit Voltage Output SoftSpan DAC driver
4 * LTC2672 5 channel, 12-/16-Bit Current Output Softspan DAC driver
5 *
6 * Copyright 2024 Analog Devices Inc.
7 */
8
9 #include <linux/bitfield.h>
10 #include <linux/cleanup.h>
11 #include <linux/device.h>
12 #include <linux/gpio/consumer.h>
13 #include <linux/iio/iio.h>
14 #include <linux/kernel.h>
15 #include <linux/math64.h>
16 #include <linux/module.h>
17 #include <linux/mod_devicetable.h>
18 #include <linux/mutex.h>
19 #include <linux/property.h>
20 #include <linux/regmap.h>
21 #include <linux/regulator/consumer.h>
22 #include <linux/spi/spi.h>
23
24 #define LTC2664_CMD_WRITE_N(n) (0x00 + (n))
25 #define LTC2664_CMD_UPDATE_N(n) (0x10 + (n))
26 #define LTC2664_CMD_WRITE_N_UPDATE_ALL 0x20
27 #define LTC2664_CMD_WRITE_N_UPDATE_N(n) (0x30 + (n))
28 #define LTC2664_CMD_POWER_DOWN_N(n) (0x40 + (n))
29 #define LTC2664_CMD_POWER_DOWN_ALL 0x50
30 #define LTC2664_CMD_SPAN_N(n) (0x60 + (n))
31 #define LTC2664_CMD_CONFIG 0x70
32 #define LTC2664_CMD_MUX 0xB0
33 #define LTC2664_CMD_TOGGLE_SEL 0xC0
34 #define LTC2664_CMD_GLOBAL_TOGGLE 0xD0
35 #define LTC2664_CMD_NO_OPERATION 0xF0
36 #define LTC2664_REF_DISABLE 0x0001
37 #define LTC2664_MSPAN_SOFTSPAN 7
38
39 #define LTC2672_MAX_CHANNEL 5
40 #define LTC2672_MAX_SPAN 7
41 #define LTC2672_SCALE_MULTIPLIER(n) (50 * BIT(n))
42
43 enum {
44 LTC2664_SPAN_RANGE_0V_5V,
45 LTC2664_SPAN_RANGE_0V_10V,
46 LTC2664_SPAN_RANGE_M5V_5V,
47 LTC2664_SPAN_RANGE_M10V_10V,
48 LTC2664_SPAN_RANGE_M2V5_2V5,
49 };
50
51 enum {
52 LTC2664_INPUT_A,
53 LTC2664_INPUT_B,
54 LTC2664_INPUT_B_AVAIL,
55 LTC2664_POWERDOWN,
56 LTC2664_POWERDOWN_MODE,
57 LTC2664_TOGGLE_EN,
58 LTC2664_GLOBAL_TOGGLE,
59 };
60
61 static const u16 ltc2664_mspan_lut[8][2] = {
62 { LTC2664_SPAN_RANGE_M10V_10V, 32768 }, /* MPS2=0, MPS1=0, MSP0=0 (0)*/
63 { LTC2664_SPAN_RANGE_M5V_5V, 32768 }, /* MPS2=0, MPS1=0, MSP0=1 (1)*/
64 { LTC2664_SPAN_RANGE_M2V5_2V5, 32768 }, /* MPS2=0, MPS1=1, MSP0=0 (2)*/
65 { LTC2664_SPAN_RANGE_0V_10V, 0 }, /* MPS2=0, MPS1=1, MSP0=1 (3)*/
66 { LTC2664_SPAN_RANGE_0V_10V, 32768 }, /* MPS2=1, MPS1=0, MSP0=0 (4)*/
67 { LTC2664_SPAN_RANGE_0V_5V, 0 }, /* MPS2=1, MPS1=0, MSP0=1 (5)*/
68 { LTC2664_SPAN_RANGE_0V_5V, 32768 }, /* MPS2=1, MPS1=1, MSP0=0 (6)*/
69 { LTC2664_SPAN_RANGE_0V_5V, 0 } /* MPS2=1, MPS1=1, MSP0=1 (7)*/
70 };
71
72 struct ltc2664_state;
73
74 struct ltc2664_chip_info {
75 const char *name;
76 int (*scale_get)(const struct ltc2664_state *st, int c);
77 int (*offset_get)(const struct ltc2664_state *st, int c);
78 int measurement_type;
79 unsigned int num_channels;
80 const int (*span_helper)[2];
81 unsigned int num_span;
82 unsigned int internal_vref_mv;
83 bool manual_span_support;
84 bool rfsadj_support;
85 };
86
87 struct ltc2664_chan {
88 /* indicates if the channel should be toggled */
89 bool toggle_chan;
90 /* indicates if the channel is in powered down state */
91 bool powerdown;
92 /* span code of the channel */
93 u8 span;
94 /* raw data of the current state of the chip registers (A/B) */
95 u16 raw[2];
96 };
97
98 struct ltc2664_state {
99 struct spi_device *spi;
100 struct regmap *regmap;
101 struct ltc2664_chan channels[LTC2672_MAX_CHANNEL];
102 /* lock to protect against multiple access to the device and shared data */
103 struct mutex lock;
104 const struct ltc2664_chip_info *chip_info;
105 struct iio_chan_spec *iio_channels;
106 int vref_mv;
107 u32 rfsadj_ohms;
108 u32 toggle_sel;
109 bool global_toggle;
110 };
111
112 static const int ltc2664_span_helper[][2] = {
113 { 0, 5000 },
114 { 0, 10000 },
115 { -5000, 5000 },
116 { -10000, 10000 },
117 { -2500, 2500 },
118 };
119
120 static const int ltc2672_span_helper[][2] = {
121 { 0, 0 },
122 { 0, 3125 },
123 { 0, 6250 },
124 { 0, 12500 },
125 { 0, 25000 },
126 { 0, 50000 },
127 { 0, 100000 },
128 { 0, 200000 },
129 { 0, 300000 },
130 };
131
ltc2664_scale_get(const struct ltc2664_state * st,int c)132 static int ltc2664_scale_get(const struct ltc2664_state *st, int c)
133 {
134 const struct ltc2664_chan *chan = &st->channels[c];
135 const int (*span_helper)[2] = st->chip_info->span_helper;
136 int span, fs;
137
138 span = chan->span;
139 if (span < 0)
140 return span;
141
142 fs = span_helper[span][1] - span_helper[span][0];
143
144 return fs * st->vref_mv / 2500;
145 }
146
ltc2672_scale_get(const struct ltc2664_state * st,int c)147 static int ltc2672_scale_get(const struct ltc2664_state *st, int c)
148 {
149 const struct ltc2664_chan *chan = &st->channels[c];
150 int span, fs;
151
152 span = chan->span - 1;
153 if (span < 0)
154 return span;
155
156 fs = 1000 * st->vref_mv;
157
158 if (span == LTC2672_MAX_SPAN)
159 return mul_u64_u32_div(4800, fs, st->rfsadj_ohms);
160
161 return mul_u64_u32_div(LTC2672_SCALE_MULTIPLIER(span), fs, st->rfsadj_ohms);
162 }
163
ltc2664_offset_get(const struct ltc2664_state * st,int c)164 static int ltc2664_offset_get(const struct ltc2664_state *st, int c)
165 {
166 const struct ltc2664_chan *chan = &st->channels[c];
167 int span;
168
169 span = chan->span;
170 if (span < 0)
171 return span;
172
173 if (st->chip_info->span_helper[span][0] < 0)
174 return -32768;
175
176 return 0;
177 }
178
ltc2664_dac_code_write(struct ltc2664_state * st,u32 chan,u32 input,u16 code)179 static int ltc2664_dac_code_write(struct ltc2664_state *st, u32 chan, u32 input,
180 u16 code)
181 {
182 struct ltc2664_chan *c = &st->channels[chan];
183 int ret, reg;
184
185 guard(mutex)(&st->lock);
186 /* select the correct input register to write to */
187 if (c->toggle_chan) {
188 ret = regmap_write(st->regmap, LTC2664_CMD_TOGGLE_SEL,
189 input << chan);
190 if (ret)
191 return ret;
192 }
193 /*
194 * If in toggle mode the dac should be updated by an
195 * external signal (or sw toggle) and not here.
196 */
197 if (st->toggle_sel & BIT(chan))
198 reg = LTC2664_CMD_WRITE_N(chan);
199 else
200 reg = LTC2664_CMD_WRITE_N_UPDATE_N(chan);
201
202 ret = regmap_write(st->regmap, reg, code);
203 if (ret)
204 return ret;
205
206 c->raw[input] = code;
207
208 if (c->toggle_chan) {
209 ret = regmap_write(st->regmap, LTC2664_CMD_TOGGLE_SEL,
210 st->toggle_sel);
211 if (ret)
212 return ret;
213 }
214
215 return 0;
216 }
217
ltc2664_dac_code_read(struct ltc2664_state * st,u32 chan,u32 input,u32 * code)218 static void ltc2664_dac_code_read(struct ltc2664_state *st, u32 chan, u32 input,
219 u32 *code)
220 {
221 guard(mutex)(&st->lock);
222 *code = st->channels[chan].raw[input];
223 }
224
225 static const int ltc2664_raw_range[] = { 0, 1, U16_MAX };
226
ltc2664_read_avail(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,const int ** vals,int * type,int * length,long info)227 static int ltc2664_read_avail(struct iio_dev *indio_dev,
228 struct iio_chan_spec const *chan,
229 const int **vals, int *type, int *length,
230 long info)
231 {
232 switch (info) {
233 case IIO_CHAN_INFO_RAW:
234 *vals = ltc2664_raw_range;
235 *type = IIO_VAL_INT;
236
237 return IIO_AVAIL_RANGE;
238 default:
239 return -EINVAL;
240 }
241 }
242
ltc2664_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long info)243 static int ltc2664_read_raw(struct iio_dev *indio_dev,
244 struct iio_chan_spec const *chan, int *val,
245 int *val2, long info)
246 {
247 struct ltc2664_state *st = iio_priv(indio_dev);
248
249 switch (info) {
250 case IIO_CHAN_INFO_RAW:
251 ltc2664_dac_code_read(st, chan->channel, LTC2664_INPUT_A, val);
252
253 return IIO_VAL_INT;
254 case IIO_CHAN_INFO_OFFSET:
255 *val = st->chip_info->offset_get(st, chan->channel);
256
257 return IIO_VAL_INT;
258 case IIO_CHAN_INFO_SCALE:
259 *val = st->chip_info->scale_get(st, chan->channel);
260
261 *val2 = 16;
262 return IIO_VAL_FRACTIONAL_LOG2;
263 default:
264 return -EINVAL;
265 }
266 }
267
ltc2664_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long info)268 static int ltc2664_write_raw(struct iio_dev *indio_dev,
269 struct iio_chan_spec const *chan, int val,
270 int val2, long info)
271 {
272 struct ltc2664_state *st = iio_priv(indio_dev);
273
274 switch (info) {
275 case IIO_CHAN_INFO_RAW:
276 if (val > U16_MAX || val < 0)
277 return -EINVAL;
278
279 return ltc2664_dac_code_write(st, chan->channel,
280 LTC2664_INPUT_A, val);
281 default:
282 return -EINVAL;
283 }
284 }
285
ltc2664_reg_bool_get(struct iio_dev * indio_dev,uintptr_t private,const struct iio_chan_spec * chan,char * buf)286 static ssize_t ltc2664_reg_bool_get(struct iio_dev *indio_dev,
287 uintptr_t private,
288 const struct iio_chan_spec *chan,
289 char *buf)
290 {
291 struct ltc2664_state *st = iio_priv(indio_dev);
292 u32 val;
293
294 guard(mutex)(&st->lock);
295 switch (private) {
296 case LTC2664_POWERDOWN:
297 val = st->channels[chan->channel].powerdown;
298
299 return sysfs_emit(buf, "%u\n", val);
300 case LTC2664_POWERDOWN_MODE:
301 return sysfs_emit(buf, "42kohm_to_gnd\n");
302 case LTC2664_TOGGLE_EN:
303 val = !!(st->toggle_sel & BIT(chan->channel));
304
305 return sysfs_emit(buf, "%u\n", val);
306 case LTC2664_GLOBAL_TOGGLE:
307 val = st->global_toggle;
308
309 return sysfs_emit(buf, "%u\n", val);
310 default:
311 return -EINVAL;
312 }
313 }
314
ltc2664_reg_bool_set(struct iio_dev * indio_dev,uintptr_t private,const struct iio_chan_spec * chan,const char * buf,size_t len)315 static ssize_t ltc2664_reg_bool_set(struct iio_dev *indio_dev,
316 uintptr_t private,
317 const struct iio_chan_spec *chan,
318 const char *buf, size_t len)
319 {
320 struct ltc2664_state *st = iio_priv(indio_dev);
321 int ret;
322 bool en;
323
324 ret = kstrtobool(buf, &en);
325 if (ret)
326 return ret;
327
328 guard(mutex)(&st->lock);
329 switch (private) {
330 case LTC2664_POWERDOWN:
331 ret = regmap_write(st->regmap,
332 en ? LTC2664_CMD_POWER_DOWN_N(chan->channel) :
333 LTC2664_CMD_UPDATE_N(chan->channel), en);
334 if (ret)
335 return ret;
336
337 st->channels[chan->channel].powerdown = en;
338
339 return len;
340 case LTC2664_TOGGLE_EN:
341 if (en)
342 st->toggle_sel |= BIT(chan->channel);
343 else
344 st->toggle_sel &= ~BIT(chan->channel);
345
346 ret = regmap_write(st->regmap, LTC2664_CMD_TOGGLE_SEL,
347 st->toggle_sel);
348 if (ret)
349 return ret;
350
351 return len;
352 case LTC2664_GLOBAL_TOGGLE:
353 ret = regmap_write(st->regmap, LTC2664_CMD_GLOBAL_TOGGLE, en);
354 if (ret)
355 return ret;
356
357 st->global_toggle = en;
358
359 return len;
360 default:
361 return -EINVAL;
362 }
363 }
364
ltc2664_dac_input_read(struct iio_dev * indio_dev,uintptr_t private,const struct iio_chan_spec * chan,char * buf)365 static ssize_t ltc2664_dac_input_read(struct iio_dev *indio_dev,
366 uintptr_t private,
367 const struct iio_chan_spec *chan,
368 char *buf)
369 {
370 struct ltc2664_state *st = iio_priv(indio_dev);
371 u32 val;
372
373 if (private == LTC2664_INPUT_B_AVAIL)
374 return sysfs_emit(buf, "[%u %u %u]\n", ltc2664_raw_range[0],
375 ltc2664_raw_range[1],
376 ltc2664_raw_range[2] / 4);
377
378 ltc2664_dac_code_read(st, chan->channel, private, &val);
379
380 return sysfs_emit(buf, "%u\n", val);
381 }
382
ltc2664_dac_input_write(struct iio_dev * indio_dev,uintptr_t private,const struct iio_chan_spec * chan,const char * buf,size_t len)383 static ssize_t ltc2664_dac_input_write(struct iio_dev *indio_dev,
384 uintptr_t private,
385 const struct iio_chan_spec *chan,
386 const char *buf, size_t len)
387 {
388 struct ltc2664_state *st = iio_priv(indio_dev);
389 int ret;
390 u16 val;
391
392 if (private == LTC2664_INPUT_B_AVAIL)
393 return -EINVAL;
394
395 ret = kstrtou16(buf, 10, &val);
396 if (ret)
397 return ret;
398
399 ret = ltc2664_dac_code_write(st, chan->channel, private, val);
400 if (ret)
401 return ret;
402
403 return len;
404 }
405
ltc2664_reg_access(struct iio_dev * indio_dev,unsigned int reg,unsigned int writeval,unsigned int * readval)406 static int ltc2664_reg_access(struct iio_dev *indio_dev,
407 unsigned int reg,
408 unsigned int writeval,
409 unsigned int *readval)
410 {
411 struct ltc2664_state *st = iio_priv(indio_dev);
412
413 if (readval)
414 return -EOPNOTSUPP;
415
416 return regmap_write(st->regmap, reg, writeval);
417 }
418
419 #define LTC2664_CHAN_EXT_INFO(_name, _what, _shared, _read, _write) { \
420 .name = _name, \
421 .read = (_read), \
422 .write = (_write), \
423 .private = (_what), \
424 .shared = (_shared), \
425 }
426
427 /*
428 * For toggle mode we only expose the symbol attr (sw_toggle) in case a TGPx is
429 * not provided in dts.
430 */
431 static const struct iio_chan_spec_ext_info ltc2664_toggle_sym_ext_info[] = {
432 LTC2664_CHAN_EXT_INFO("raw0", LTC2664_INPUT_A, IIO_SEPARATE,
433 ltc2664_dac_input_read, ltc2664_dac_input_write),
434 LTC2664_CHAN_EXT_INFO("raw1", LTC2664_INPUT_B, IIO_SEPARATE,
435 ltc2664_dac_input_read, ltc2664_dac_input_write),
436 LTC2664_CHAN_EXT_INFO("powerdown", LTC2664_POWERDOWN, IIO_SEPARATE,
437 ltc2664_reg_bool_get, ltc2664_reg_bool_set),
438 LTC2664_CHAN_EXT_INFO("powerdown_mode", LTC2664_POWERDOWN_MODE,
439 IIO_SEPARATE, ltc2664_reg_bool_get, NULL),
440 LTC2664_CHAN_EXT_INFO("symbol", LTC2664_GLOBAL_TOGGLE, IIO_SEPARATE,
441 ltc2664_reg_bool_get, ltc2664_reg_bool_set),
442 LTC2664_CHAN_EXT_INFO("toggle_en", LTC2664_TOGGLE_EN,
443 IIO_SEPARATE, ltc2664_reg_bool_get,
444 ltc2664_reg_bool_set),
445 { }
446 };
447
448 static const struct iio_chan_spec_ext_info ltc2664_ext_info[] = {
449 LTC2664_CHAN_EXT_INFO("powerdown", LTC2664_POWERDOWN, IIO_SEPARATE,
450 ltc2664_reg_bool_get, ltc2664_reg_bool_set),
451 LTC2664_CHAN_EXT_INFO("powerdown_mode", LTC2664_POWERDOWN_MODE,
452 IIO_SEPARATE, ltc2664_reg_bool_get, NULL),
453 { }
454 };
455
456 static const struct iio_chan_spec ltc2664_channel_template = {
457 .indexed = 1,
458 .output = 1,
459 .info_mask_separate = BIT(IIO_CHAN_INFO_SCALE) |
460 BIT(IIO_CHAN_INFO_OFFSET) |
461 BIT(IIO_CHAN_INFO_RAW),
462 .info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW),
463 .ext_info = ltc2664_ext_info,
464 };
465
466 static const struct ltc2664_chip_info ltc2664_chip = {
467 .name = "ltc2664",
468 .scale_get = ltc2664_scale_get,
469 .offset_get = ltc2664_offset_get,
470 .measurement_type = IIO_VOLTAGE,
471 .num_channels = 4,
472 .span_helper = ltc2664_span_helper,
473 .num_span = ARRAY_SIZE(ltc2664_span_helper),
474 .internal_vref_mv = 2500,
475 .manual_span_support = true,
476 .rfsadj_support = false,
477 };
478
479 static const struct ltc2664_chip_info ltc2672_chip = {
480 .name = "ltc2672",
481 .scale_get = ltc2672_scale_get,
482 .offset_get = ltc2664_offset_get,
483 .measurement_type = IIO_CURRENT,
484 .num_channels = 5,
485 .span_helper = ltc2672_span_helper,
486 .num_span = ARRAY_SIZE(ltc2672_span_helper),
487 .internal_vref_mv = 1250,
488 .manual_span_support = false,
489 .rfsadj_support = true,
490 };
491
ltc2664_set_span(const struct ltc2664_state * st,int min,int max,int chan)492 static int ltc2664_set_span(const struct ltc2664_state *st, int min, int max,
493 int chan)
494 {
495 const struct ltc2664_chip_info *chip_info = st->chip_info;
496 const int (*span_helper)[2] = chip_info->span_helper;
497 int span, ret;
498
499 for (span = 0; span < chip_info->num_span; span++) {
500 if (min == span_helper[span][0] && max == span_helper[span][1])
501 break;
502 }
503
504 if (span == chip_info->num_span)
505 return -EINVAL;
506
507 ret = regmap_write(st->regmap, LTC2664_CMD_SPAN_N(chan), span);
508 if (ret)
509 return ret;
510
511 return span;
512 }
513
ltc2664_channel_config(struct ltc2664_state * st)514 static int ltc2664_channel_config(struct ltc2664_state *st)
515 {
516 const struct ltc2664_chip_info *chip_info = st->chip_info;
517 struct device *dev = &st->spi->dev;
518 u32 reg, tmp[2], mspan;
519 int ret;
520
521 mspan = LTC2664_MSPAN_SOFTSPAN;
522 ret = device_property_read_u32(dev, "adi,manual-span-operation-config",
523 &mspan);
524 if (!ret) {
525 if (!chip_info->manual_span_support)
526 return dev_err_probe(dev, -EINVAL,
527 "adi,manual-span-operation-config not supported\n");
528
529 if (mspan >= ARRAY_SIZE(ltc2664_mspan_lut))
530 return dev_err_probe(dev, -EINVAL,
531 "adi,manual-span-operation-config not in range\n");
532 }
533
534 st->rfsadj_ohms = 20000;
535 ret = device_property_read_u32(dev, "adi,rfsadj-ohms", &st->rfsadj_ohms);
536 if (!ret) {
537 if (!chip_info->rfsadj_support)
538 return dev_err_probe(dev, -EINVAL,
539 "adi,rfsadj-ohms not supported\n");
540
541 if (st->rfsadj_ohms < 19000 || st->rfsadj_ohms > 41000)
542 return dev_err_probe(dev, -EINVAL,
543 "adi,rfsadj-ohms not in range\n");
544 }
545
546 device_for_each_child_node_scoped(dev, child) {
547 struct ltc2664_chan *chan;
548
549 ret = fwnode_property_read_u32(child, "reg", ®);
550 if (ret)
551 return dev_err_probe(dev, ret,
552 "Failed to get reg property\n");
553
554 if (reg >= chip_info->num_channels)
555 return dev_err_probe(dev, -EINVAL,
556 "reg bigger than: %d\n",
557 chip_info->num_channels);
558
559 chan = &st->channels[reg];
560
561 if (fwnode_property_read_bool(child, "adi,toggle-mode")) {
562 chan->toggle_chan = true;
563 /* assume sw toggle ABI */
564 st->iio_channels[reg].ext_info = ltc2664_toggle_sym_ext_info;
565
566 /*
567 * Clear IIO_CHAN_INFO_RAW bit as toggle channels expose
568 * out_voltage/current_raw{0|1} files.
569 */
570 __clear_bit(IIO_CHAN_INFO_RAW,
571 &st->iio_channels[reg].info_mask_separate);
572 }
573
574 chan->raw[0] = ltc2664_mspan_lut[mspan][1];
575 chan->raw[1] = ltc2664_mspan_lut[mspan][1];
576
577 chan->span = ltc2664_mspan_lut[mspan][0];
578
579 ret = fwnode_property_read_u32_array(child, "output-range-microvolt",
580 tmp, ARRAY_SIZE(tmp));
581 if (!ret && mspan == LTC2664_MSPAN_SOFTSPAN) {
582 ret = ltc2664_set_span(st, tmp[0] / 1000, tmp[1] / 1000, reg);
583 if (ret < 0)
584 return dev_err_probe(dev, ret,
585 "Failed to set span\n");
586 chan->span = ret;
587 }
588
589 ret = fwnode_property_read_u32_array(child, "output-range-microamp",
590 tmp, ARRAY_SIZE(tmp));
591 if (!ret) {
592 ret = ltc2664_set_span(st, 0, tmp[1] / 1000, reg);
593 if (ret < 0)
594 return dev_err_probe(dev, ret,
595 "Failed to set span\n");
596 chan->span = ret;
597 }
598 }
599
600 return 0;
601 }
602
ltc2664_setup(struct ltc2664_state * st)603 static int ltc2664_setup(struct ltc2664_state *st)
604 {
605 const struct ltc2664_chip_info *chip_info = st->chip_info;
606 struct gpio_desc *gpio;
607 int ret, i;
608
609 /* If we have a clr/reset pin, use that to reset the chip. */
610 gpio = devm_gpiod_get_optional(&st->spi->dev, "reset", GPIOD_OUT_HIGH);
611 if (IS_ERR(gpio))
612 return dev_err_probe(&st->spi->dev, PTR_ERR(gpio),
613 "Failed to get reset gpio");
614 if (gpio) {
615 fsleep(1000);
616 gpiod_set_value_cansleep(gpio, 0);
617 }
618
619 /*
620 * Duplicate the default channel configuration as it can change during
621 * @ltc2664_channel_config()
622 */
623 st->iio_channels = devm_kcalloc(&st->spi->dev,
624 chip_info->num_channels,
625 sizeof(struct iio_chan_spec),
626 GFP_KERNEL);
627 if (!st->iio_channels)
628 return -ENOMEM;
629
630 for (i = 0; i < chip_info->num_channels; i++) {
631 st->iio_channels[i] = ltc2664_channel_template;
632 st->iio_channels[i].type = chip_info->measurement_type;
633 st->iio_channels[i].channel = i;
634 }
635
636 ret = ltc2664_channel_config(st);
637 if (ret)
638 return ret;
639
640 return regmap_set_bits(st->regmap, LTC2664_CMD_CONFIG, LTC2664_REF_DISABLE);
641 }
642
643 static const struct regmap_config ltc2664_regmap_config = {
644 .reg_bits = 8,
645 .val_bits = 16,
646 .max_register = LTC2664_CMD_NO_OPERATION,
647 };
648
649 static const struct iio_info ltc2664_info = {
650 .write_raw = ltc2664_write_raw,
651 .read_raw = ltc2664_read_raw,
652 .read_avail = ltc2664_read_avail,
653 .debugfs_reg_access = ltc2664_reg_access,
654 };
655
ltc2664_probe(struct spi_device * spi)656 static int ltc2664_probe(struct spi_device *spi)
657 {
658 static const char * const regulators[] = { "vcc", "iovcc", "v-neg" };
659 const struct ltc2664_chip_info *chip_info;
660 struct device *dev = &spi->dev;
661 struct iio_dev *indio_dev;
662 struct ltc2664_state *st;
663 int ret;
664
665 indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
666 if (!indio_dev)
667 return -ENOMEM;
668
669 st = iio_priv(indio_dev);
670 st->spi = spi;
671
672 chip_info = spi_get_device_match_data(spi);
673 if (!chip_info)
674 return -ENODEV;
675
676 st->chip_info = chip_info;
677
678 mutex_init(&st->lock);
679
680 st->regmap = devm_regmap_init_spi(spi, <c2664_regmap_config);
681 if (IS_ERR(st->regmap))
682 return dev_err_probe(dev, PTR_ERR(st->regmap),
683 "Failed to init regmap");
684
685 ret = devm_regulator_bulk_get_enable(dev, ARRAY_SIZE(regulators),
686 regulators);
687 if (ret)
688 return dev_err_probe(dev, ret, "Failed to enable regulators\n");
689
690 ret = devm_regulator_get_enable_read_voltage(dev, "ref");
691 if (ret < 0 && ret != -ENODEV)
692 return ret;
693
694 st->vref_mv = ret > 0 ? ret / 1000 : chip_info->internal_vref_mv;
695
696 ret = ltc2664_setup(st);
697 if (ret)
698 return ret;
699
700 indio_dev->name = chip_info->name;
701 indio_dev->info = <c2664_info;
702 indio_dev->modes = INDIO_DIRECT_MODE;
703 indio_dev->channels = st->iio_channels;
704 indio_dev->num_channels = chip_info->num_channels;
705
706 return devm_iio_device_register(dev, indio_dev);
707 }
708
709 static const struct spi_device_id ltc2664_id[] = {
710 { "ltc2664", (kernel_ulong_t)<c2664_chip },
711 { "ltc2672", (kernel_ulong_t)<c2672_chip },
712 { }
713 };
714 MODULE_DEVICE_TABLE(spi, ltc2664_id);
715
716 static const struct of_device_id ltc2664_of_id[] = {
717 { .compatible = "adi,ltc2664", .data = <c2664_chip },
718 { .compatible = "adi,ltc2672", .data = <c2672_chip },
719 { }
720 };
721 MODULE_DEVICE_TABLE(of, ltc2664_of_id);
722
723 static struct spi_driver ltc2664_driver = {
724 .driver = {
725 .name = "ltc2664",
726 .of_match_table = ltc2664_of_id,
727 },
728 .probe = ltc2664_probe,
729 .id_table = ltc2664_id,
730 };
731 module_spi_driver(ltc2664_driver);
732
733 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
734 MODULE_AUTHOR("Kim Seer Paller <kimseer.paller@analog.com>");
735 MODULE_DESCRIPTION("Analog Devices LTC2664 and LTC2672 DAC");
736 MODULE_LICENSE("GPL");
737