xref: /openbmc/linux/drivers/iio/dac/ad5380.c (revision 4cff79e9)
1 /*
2  * Analog devices AD5380, AD5381, AD5382, AD5383, AD5390, AD5391, AD5392
3  * multi-channel Digital to Analog Converters driver
4  *
5  * Copyright 2011 Analog Devices Inc.
6  *
7  * Licensed under the GPL-2.
8  */
9 
10 #include <linux/device.h>
11 #include <linux/err.h>
12 #include <linux/i2c.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/spi/spi.h>
16 #include <linux/slab.h>
17 #include <linux/sysfs.h>
18 #include <linux/regmap.h>
19 #include <linux/regulator/consumer.h>
20 
21 #include <linux/iio/iio.h>
22 #include <linux/iio/sysfs.h>
23 
24 #define AD5380_REG_DATA(x)	(((x) << 2) | 3)
25 #define AD5380_REG_OFFSET(x)	(((x) << 2) | 2)
26 #define AD5380_REG_GAIN(x)	(((x) << 2) | 1)
27 #define AD5380_REG_SF_PWR_DOWN	(8 << 2)
28 #define AD5380_REG_SF_PWR_UP	(9 << 2)
29 #define AD5380_REG_SF_CTRL	(12 << 2)
30 
31 #define AD5380_CTRL_PWR_DOWN_MODE_OFFSET	13
32 #define AD5380_CTRL_INT_VREF_2V5		BIT(12)
33 #define AD5380_CTRL_INT_VREF_EN			BIT(10)
34 
35 /**
36  * struct ad5380_chip_info - chip specific information
37  * @channel_template:	channel specification template
38  * @num_channels:	number of channels
39  * @int_vref:		internal vref in uV
40 */
41 
42 struct ad5380_chip_info {
43 	struct iio_chan_spec	channel_template;
44 	unsigned int		num_channels;
45 	unsigned int		int_vref;
46 };
47 
48 /**
49  * struct ad5380_state - driver instance specific data
50  * @regmap:		regmap instance used by the device
51  * @chip_info:		chip model specific constants, available modes etc
52  * @vref_reg:		vref supply regulator
53  * @vref:		actual reference voltage used in uA
54  * @pwr_down:		whether the chip is currently in power down mode
55  */
56 
57 struct ad5380_state {
58 	struct regmap			*regmap;
59 	const struct ad5380_chip_info	*chip_info;
60 	struct regulator		*vref_reg;
61 	int				vref;
62 	bool				pwr_down;
63 };
64 
65 enum ad5380_type {
66 	ID_AD5380_3,
67 	ID_AD5380_5,
68 	ID_AD5381_3,
69 	ID_AD5381_5,
70 	ID_AD5382_3,
71 	ID_AD5382_5,
72 	ID_AD5383_3,
73 	ID_AD5383_5,
74 	ID_AD5390_3,
75 	ID_AD5390_5,
76 	ID_AD5391_3,
77 	ID_AD5391_5,
78 	ID_AD5392_3,
79 	ID_AD5392_5,
80 };
81 
82 static ssize_t ad5380_read_dac_powerdown(struct iio_dev *indio_dev,
83 	uintptr_t private, const struct iio_chan_spec *chan, char *buf)
84 {
85 	struct ad5380_state *st = iio_priv(indio_dev);
86 
87 	return sprintf(buf, "%d\n", st->pwr_down);
88 }
89 
90 static ssize_t ad5380_write_dac_powerdown(struct iio_dev *indio_dev,
91 	 uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
92 	 size_t len)
93 {
94 	struct ad5380_state *st = iio_priv(indio_dev);
95 	bool pwr_down;
96 	int ret;
97 
98 	ret = strtobool(buf, &pwr_down);
99 	if (ret)
100 		return ret;
101 
102 	mutex_lock(&indio_dev->mlock);
103 
104 	if (pwr_down)
105 		ret = regmap_write(st->regmap, AD5380_REG_SF_PWR_DOWN, 0);
106 	else
107 		ret = regmap_write(st->regmap, AD5380_REG_SF_PWR_UP, 0);
108 
109 	st->pwr_down = pwr_down;
110 
111 	mutex_unlock(&indio_dev->mlock);
112 
113 	return ret ? ret : len;
114 }
115 
116 static const char * const ad5380_powerdown_modes[] = {
117 	"100kohm_to_gnd",
118 	"three_state",
119 };
120 
121 static int ad5380_get_powerdown_mode(struct iio_dev *indio_dev,
122 	const struct iio_chan_spec *chan)
123 {
124 	struct ad5380_state *st = iio_priv(indio_dev);
125 	unsigned int mode;
126 	int ret;
127 
128 	ret = regmap_read(st->regmap, AD5380_REG_SF_CTRL, &mode);
129 	if (ret)
130 		return ret;
131 
132 	mode = (mode >> AD5380_CTRL_PWR_DOWN_MODE_OFFSET) & 1;
133 
134 	return mode;
135 }
136 
137 static int ad5380_set_powerdown_mode(struct iio_dev *indio_dev,
138 	const struct iio_chan_spec *chan, unsigned int mode)
139 {
140 	struct ad5380_state *st = iio_priv(indio_dev);
141 	int ret;
142 
143 	ret = regmap_update_bits(st->regmap, AD5380_REG_SF_CTRL,
144 		1 << AD5380_CTRL_PWR_DOWN_MODE_OFFSET,
145 		mode << AD5380_CTRL_PWR_DOWN_MODE_OFFSET);
146 
147 	return ret;
148 }
149 
150 static const struct iio_enum ad5380_powerdown_mode_enum = {
151 	.items = ad5380_powerdown_modes,
152 	.num_items = ARRAY_SIZE(ad5380_powerdown_modes),
153 	.get = ad5380_get_powerdown_mode,
154 	.set = ad5380_set_powerdown_mode,
155 };
156 
157 static unsigned int ad5380_info_to_reg(struct iio_chan_spec const *chan,
158 	long info)
159 {
160 	switch (info) {
161 	case IIO_CHAN_INFO_RAW:
162 		return AD5380_REG_DATA(chan->address);
163 	case IIO_CHAN_INFO_CALIBBIAS:
164 		return AD5380_REG_OFFSET(chan->address);
165 	case IIO_CHAN_INFO_CALIBSCALE:
166 		return AD5380_REG_GAIN(chan->address);
167 	default:
168 		break;
169 	}
170 
171 	return 0;
172 }
173 
174 static int ad5380_write_raw(struct iio_dev *indio_dev,
175 	struct iio_chan_spec const *chan, int val, int val2, long info)
176 {
177 	const unsigned int max_val = (1 << chan->scan_type.realbits);
178 	struct ad5380_state *st = iio_priv(indio_dev);
179 
180 	switch (info) {
181 	case IIO_CHAN_INFO_RAW:
182 	case IIO_CHAN_INFO_CALIBSCALE:
183 		if (val >= max_val || val < 0)
184 			return -EINVAL;
185 
186 		return regmap_write(st->regmap,
187 			ad5380_info_to_reg(chan, info),
188 			val << chan->scan_type.shift);
189 	case IIO_CHAN_INFO_CALIBBIAS:
190 		val += (1 << chan->scan_type.realbits) / 2;
191 		if (val >= max_val || val < 0)
192 			return -EINVAL;
193 
194 		return regmap_write(st->regmap,
195 			AD5380_REG_OFFSET(chan->address),
196 			val << chan->scan_type.shift);
197 	default:
198 		break;
199 	}
200 	return -EINVAL;
201 }
202 
203 static int ad5380_read_raw(struct iio_dev *indio_dev,
204 	struct iio_chan_spec const *chan, int *val, int *val2, long info)
205 {
206 	struct ad5380_state *st = iio_priv(indio_dev);
207 	int ret;
208 
209 	switch (info) {
210 	case IIO_CHAN_INFO_RAW:
211 	case IIO_CHAN_INFO_CALIBSCALE:
212 		ret = regmap_read(st->regmap, ad5380_info_to_reg(chan, info),
213 					val);
214 		if (ret)
215 			return ret;
216 		*val >>= chan->scan_type.shift;
217 		return IIO_VAL_INT;
218 	case IIO_CHAN_INFO_CALIBBIAS:
219 		ret = regmap_read(st->regmap, AD5380_REG_OFFSET(chan->address),
220 					val);
221 		if (ret)
222 			return ret;
223 		*val >>= chan->scan_type.shift;
224 		val -= (1 << chan->scan_type.realbits) / 2;
225 		return IIO_VAL_INT;
226 	case IIO_CHAN_INFO_SCALE:
227 		*val = 2 * st->vref;
228 		*val2 = chan->scan_type.realbits;
229 		return IIO_VAL_FRACTIONAL_LOG2;
230 	default:
231 		break;
232 	}
233 
234 	return -EINVAL;
235 }
236 
237 static const struct iio_info ad5380_info = {
238 	.read_raw = ad5380_read_raw,
239 	.write_raw = ad5380_write_raw,
240 };
241 
242 static struct iio_chan_spec_ext_info ad5380_ext_info[] = {
243 	{
244 		.name = "powerdown",
245 		.read = ad5380_read_dac_powerdown,
246 		.write = ad5380_write_dac_powerdown,
247 		.shared = IIO_SEPARATE,
248 	},
249 	IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE,
250 		 &ad5380_powerdown_mode_enum),
251 	IIO_ENUM_AVAILABLE("powerdown_mode", &ad5380_powerdown_mode_enum),
252 	{ },
253 };
254 
255 #define AD5380_CHANNEL(_bits) {					\
256 	.type = IIO_VOLTAGE,					\
257 	.indexed = 1,						\
258 	.output = 1,						\
259 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
260 		BIT(IIO_CHAN_INFO_CALIBSCALE) |			\
261 		BIT(IIO_CHAN_INFO_CALIBBIAS),			\
262 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
263 	.scan_type = {						\
264 		.sign = 'u',					\
265 		.realbits = (_bits),				\
266 		.storagebits =  16,				\
267 		.shift = 14 - (_bits),				\
268 	},							\
269 	.ext_info = ad5380_ext_info,				\
270 }
271 
272 static const struct ad5380_chip_info ad5380_chip_info_tbl[] = {
273 	[ID_AD5380_3] = {
274 		.channel_template = AD5380_CHANNEL(14),
275 		.num_channels = 40,
276 		.int_vref = 1250,
277 	},
278 	[ID_AD5380_5] = {
279 		.channel_template = AD5380_CHANNEL(14),
280 		.num_channels = 40,
281 		.int_vref = 2500,
282 	},
283 	[ID_AD5381_3] = {
284 		.channel_template = AD5380_CHANNEL(12),
285 		.num_channels = 16,
286 		.int_vref = 1250,
287 	},
288 	[ID_AD5381_5] = {
289 		.channel_template = AD5380_CHANNEL(12),
290 		.num_channels = 16,
291 		.int_vref = 2500,
292 	},
293 	[ID_AD5382_3] = {
294 		.channel_template = AD5380_CHANNEL(14),
295 		.num_channels = 32,
296 		.int_vref = 1250,
297 	},
298 	[ID_AD5382_5] = {
299 		.channel_template = AD5380_CHANNEL(14),
300 		.num_channels = 32,
301 		.int_vref = 2500,
302 	},
303 	[ID_AD5383_3] = {
304 		.channel_template = AD5380_CHANNEL(12),
305 		.num_channels = 32,
306 		.int_vref = 1250,
307 	},
308 	[ID_AD5383_5] = {
309 		.channel_template = AD5380_CHANNEL(12),
310 		.num_channels = 32,
311 		.int_vref = 2500,
312 	},
313 	[ID_AD5390_3] = {
314 		.channel_template = AD5380_CHANNEL(14),
315 		.num_channels = 16,
316 		.int_vref = 1250,
317 	},
318 	[ID_AD5390_5] = {
319 		.channel_template = AD5380_CHANNEL(14),
320 		.num_channels = 16,
321 		.int_vref = 2500,
322 	},
323 	[ID_AD5391_3] = {
324 		.channel_template = AD5380_CHANNEL(12),
325 		.num_channels = 16,
326 		.int_vref = 1250,
327 	},
328 	[ID_AD5391_5] = {
329 		.channel_template = AD5380_CHANNEL(12),
330 		.num_channels = 16,
331 		.int_vref = 2500,
332 	},
333 	[ID_AD5392_3] = {
334 		.channel_template = AD5380_CHANNEL(14),
335 		.num_channels = 8,
336 		.int_vref = 1250,
337 	},
338 	[ID_AD5392_5] = {
339 		.channel_template = AD5380_CHANNEL(14),
340 		.num_channels = 8,
341 		.int_vref = 2500,
342 	},
343 };
344 
345 static int ad5380_alloc_channels(struct iio_dev *indio_dev)
346 {
347 	struct ad5380_state *st = iio_priv(indio_dev);
348 	struct iio_chan_spec *channels;
349 	unsigned int i;
350 
351 	channels = kcalloc(st->chip_info->num_channels,
352 			   sizeof(struct iio_chan_spec), GFP_KERNEL);
353 
354 	if (!channels)
355 		return -ENOMEM;
356 
357 	for (i = 0; i < st->chip_info->num_channels; ++i) {
358 		channels[i] = st->chip_info->channel_template;
359 		channels[i].channel = i;
360 		channels[i].address = i;
361 	}
362 
363 	indio_dev->channels = channels;
364 
365 	return 0;
366 }
367 
368 static int ad5380_probe(struct device *dev, struct regmap *regmap,
369 			enum ad5380_type type, const char *name)
370 {
371 	struct iio_dev *indio_dev;
372 	struct ad5380_state *st;
373 	unsigned int ctrl = 0;
374 	int ret;
375 
376 	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
377 	if (indio_dev == NULL) {
378 		dev_err(dev, "Failed to allocate iio device\n");
379 		return -ENOMEM;
380 	}
381 
382 	st = iio_priv(indio_dev);
383 	dev_set_drvdata(dev, indio_dev);
384 
385 	st->chip_info = &ad5380_chip_info_tbl[type];
386 	st->regmap = regmap;
387 
388 	indio_dev->dev.parent = dev;
389 	indio_dev->name = name;
390 	indio_dev->info = &ad5380_info;
391 	indio_dev->modes = INDIO_DIRECT_MODE;
392 	indio_dev->num_channels = st->chip_info->num_channels;
393 
394 	ret = ad5380_alloc_channels(indio_dev);
395 	if (ret) {
396 		dev_err(dev, "Failed to allocate channel spec: %d\n", ret);
397 		return ret;
398 	}
399 
400 	if (st->chip_info->int_vref == 2500)
401 		ctrl |= AD5380_CTRL_INT_VREF_2V5;
402 
403 	st->vref_reg = devm_regulator_get(dev, "vref");
404 	if (!IS_ERR(st->vref_reg)) {
405 		ret = regulator_enable(st->vref_reg);
406 		if (ret) {
407 			dev_err(dev, "Failed to enable vref regulators: %d\n",
408 				ret);
409 			goto error_free_reg;
410 		}
411 
412 		ret = regulator_get_voltage(st->vref_reg);
413 		if (ret < 0)
414 			goto error_disable_reg;
415 
416 		st->vref = ret / 1000;
417 	} else {
418 		st->vref = st->chip_info->int_vref;
419 		ctrl |= AD5380_CTRL_INT_VREF_EN;
420 	}
421 
422 	ret = regmap_write(st->regmap, AD5380_REG_SF_CTRL, ctrl);
423 	if (ret) {
424 		dev_err(dev, "Failed to write to device: %d\n", ret);
425 		goto error_disable_reg;
426 	}
427 
428 	ret = iio_device_register(indio_dev);
429 	if (ret) {
430 		dev_err(dev, "Failed to register iio device: %d\n", ret);
431 		goto error_disable_reg;
432 	}
433 
434 	return 0;
435 
436 error_disable_reg:
437 	if (!IS_ERR(st->vref_reg))
438 		regulator_disable(st->vref_reg);
439 error_free_reg:
440 	kfree(indio_dev->channels);
441 
442 	return ret;
443 }
444 
445 static int ad5380_remove(struct device *dev)
446 {
447 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
448 	struct ad5380_state *st = iio_priv(indio_dev);
449 
450 	iio_device_unregister(indio_dev);
451 
452 	kfree(indio_dev->channels);
453 
454 	if (!IS_ERR(st->vref_reg)) {
455 		regulator_disable(st->vref_reg);
456 	}
457 
458 	return 0;
459 }
460 
461 static bool ad5380_reg_false(struct device *dev, unsigned int reg)
462 {
463 	return false;
464 }
465 
466 static const struct regmap_config ad5380_regmap_config = {
467 	.reg_bits = 10,
468 	.val_bits = 14,
469 
470 	.max_register = AD5380_REG_DATA(40),
471 	.cache_type = REGCACHE_RBTREE,
472 
473 	.volatile_reg = ad5380_reg_false,
474 	.readable_reg = ad5380_reg_false,
475 };
476 
477 #if IS_ENABLED(CONFIG_SPI_MASTER)
478 
479 static int ad5380_spi_probe(struct spi_device *spi)
480 {
481 	const struct spi_device_id *id = spi_get_device_id(spi);
482 	struct regmap *regmap;
483 
484 	regmap = devm_regmap_init_spi(spi, &ad5380_regmap_config);
485 
486 	if (IS_ERR(regmap))
487 		return PTR_ERR(regmap);
488 
489 	return ad5380_probe(&spi->dev, regmap, id->driver_data, id->name);
490 }
491 
492 static int ad5380_spi_remove(struct spi_device *spi)
493 {
494 	return ad5380_remove(&spi->dev);
495 }
496 
497 static const struct spi_device_id ad5380_spi_ids[] = {
498 	{ "ad5380-3", ID_AD5380_3 },
499 	{ "ad5380-5", ID_AD5380_5 },
500 	{ "ad5381-3", ID_AD5381_3 },
501 	{ "ad5381-5", ID_AD5381_5 },
502 	{ "ad5382-3", ID_AD5382_3 },
503 	{ "ad5382-5", ID_AD5382_5 },
504 	{ "ad5383-3", ID_AD5383_3 },
505 	{ "ad5383-5", ID_AD5383_5 },
506 	{ "ad5384-3", ID_AD5380_3 },
507 	{ "ad5384-5", ID_AD5380_5 },
508 	{ "ad5390-3", ID_AD5390_3 },
509 	{ "ad5390-5", ID_AD5390_5 },
510 	{ "ad5391-3", ID_AD5391_3 },
511 	{ "ad5391-5", ID_AD5391_5 },
512 	{ "ad5392-3", ID_AD5392_3 },
513 	{ "ad5392-5", ID_AD5392_5 },
514 	{ }
515 };
516 MODULE_DEVICE_TABLE(spi, ad5380_spi_ids);
517 
518 static struct spi_driver ad5380_spi_driver = {
519 	.driver = {
520 		   .name = "ad5380",
521 	},
522 	.probe = ad5380_spi_probe,
523 	.remove = ad5380_spi_remove,
524 	.id_table = ad5380_spi_ids,
525 };
526 
527 static inline int ad5380_spi_register_driver(void)
528 {
529 	return spi_register_driver(&ad5380_spi_driver);
530 }
531 
532 static inline void ad5380_spi_unregister_driver(void)
533 {
534 	spi_unregister_driver(&ad5380_spi_driver);
535 }
536 
537 #else
538 
539 static inline int ad5380_spi_register_driver(void)
540 {
541 	return 0;
542 }
543 
544 static inline void ad5380_spi_unregister_driver(void)
545 {
546 }
547 
548 #endif
549 
550 #if IS_ENABLED(CONFIG_I2C)
551 
552 static int ad5380_i2c_probe(struct i2c_client *i2c,
553 			    const struct i2c_device_id *id)
554 {
555 	struct regmap *regmap;
556 
557 	regmap = devm_regmap_init_i2c(i2c, &ad5380_regmap_config);
558 
559 	if (IS_ERR(regmap))
560 		return PTR_ERR(regmap);
561 
562 	return ad5380_probe(&i2c->dev, regmap, id->driver_data, id->name);
563 }
564 
565 static int ad5380_i2c_remove(struct i2c_client *i2c)
566 {
567 	return ad5380_remove(&i2c->dev);
568 }
569 
570 static const struct i2c_device_id ad5380_i2c_ids[] = {
571 	{ "ad5380-3", ID_AD5380_3 },
572 	{ "ad5380-5", ID_AD5380_5 },
573 	{ "ad5381-3", ID_AD5381_3 },
574 	{ "ad5381-5", ID_AD5381_5 },
575 	{ "ad5382-3", ID_AD5382_3 },
576 	{ "ad5382-5", ID_AD5382_5 },
577 	{ "ad5383-3", ID_AD5383_3 },
578 	{ "ad5383-5", ID_AD5383_5 },
579 	{ "ad5384-3", ID_AD5380_3 },
580 	{ "ad5384-5", ID_AD5380_5 },
581 	{ "ad5390-3", ID_AD5390_3 },
582 	{ "ad5390-5", ID_AD5390_5 },
583 	{ "ad5391-3", ID_AD5391_3 },
584 	{ "ad5391-5", ID_AD5391_5 },
585 	{ "ad5392-3", ID_AD5392_3 },
586 	{ "ad5392-5", ID_AD5392_5 },
587 	{ }
588 };
589 MODULE_DEVICE_TABLE(i2c, ad5380_i2c_ids);
590 
591 static struct i2c_driver ad5380_i2c_driver = {
592 	.driver = {
593 		   .name = "ad5380",
594 	},
595 	.probe = ad5380_i2c_probe,
596 	.remove = ad5380_i2c_remove,
597 	.id_table = ad5380_i2c_ids,
598 };
599 
600 static inline int ad5380_i2c_register_driver(void)
601 {
602 	return i2c_add_driver(&ad5380_i2c_driver);
603 }
604 
605 static inline void ad5380_i2c_unregister_driver(void)
606 {
607 	i2c_del_driver(&ad5380_i2c_driver);
608 }
609 
610 #else
611 
612 static inline int ad5380_i2c_register_driver(void)
613 {
614 	return 0;
615 }
616 
617 static inline void ad5380_i2c_unregister_driver(void)
618 {
619 }
620 
621 #endif
622 
623 static int __init ad5380_spi_init(void)
624 {
625 	int ret;
626 
627 	ret = ad5380_spi_register_driver();
628 	if (ret)
629 		return ret;
630 
631 	ret = ad5380_i2c_register_driver();
632 	if (ret) {
633 		ad5380_spi_unregister_driver();
634 		return ret;
635 	}
636 
637 	return 0;
638 }
639 module_init(ad5380_spi_init);
640 
641 static void __exit ad5380_spi_exit(void)
642 {
643 	ad5380_i2c_unregister_driver();
644 	ad5380_spi_unregister_driver();
645 
646 }
647 module_exit(ad5380_spi_exit);
648 
649 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
650 MODULE_DESCRIPTION("Analog Devices AD5380/81/82/83/84/90/91/92 DAC");
651 MODULE_LICENSE("GPL v2");
652