xref: /openbmc/linux/drivers/iio/dac/ad5380.c (revision 5bd8e16d)
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 0:
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 	unsigned long scale_uv;
208 	int ret;
209 
210 	switch (info) {
211 	case IIO_CHAN_INFO_RAW:
212 	case IIO_CHAN_INFO_CALIBSCALE:
213 		ret = regmap_read(st->regmap, ad5380_info_to_reg(chan, info),
214 					val);
215 		if (ret)
216 			return ret;
217 		*val >>= chan->scan_type.shift;
218 		return IIO_VAL_INT;
219 	case IIO_CHAN_INFO_CALIBBIAS:
220 		ret = regmap_read(st->regmap, AD5380_REG_OFFSET(chan->address),
221 					val);
222 		if (ret)
223 			return ret;
224 		*val >>= chan->scan_type.shift;
225 		val -= (1 << chan->scan_type.realbits) / 2;
226 		return IIO_VAL_INT;
227 	case IIO_CHAN_INFO_SCALE:
228 		scale_uv = ((2 * st->vref) >> chan->scan_type.realbits) * 100;
229 		*val =  scale_uv / 100000;
230 		*val2 = (scale_uv % 100000) * 10;
231 		return IIO_VAL_INT_PLUS_MICRO;
232 	default:
233 		break;
234 	}
235 
236 	return -EINVAL;
237 }
238 
239 static const struct iio_info ad5380_info = {
240 	.read_raw = ad5380_read_raw,
241 	.write_raw = ad5380_write_raw,
242 	.driver_module = THIS_MODULE,
243 };
244 
245 static struct iio_chan_spec_ext_info ad5380_ext_info[] = {
246 	{
247 		.name = "powerdown",
248 		.read = ad5380_read_dac_powerdown,
249 		.write = ad5380_write_dac_powerdown,
250 	},
251 	IIO_ENUM("powerdown_mode", true, &ad5380_powerdown_mode_enum),
252 	IIO_ENUM_AVAILABLE("powerdown_mode", &ad5380_powerdown_mode_enum),
253 	{ },
254 };
255 
256 #define AD5380_CHANNEL(_bits) {					\
257 	.type = IIO_VOLTAGE,					\
258 	.indexed = 1,						\
259 	.output = 1,						\
260 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
261 		BIT(IIO_CHAN_INFO_CALIBSCALE) |			\
262 		BIT(IIO_CHAN_INFO_CALIBBIAS),			\
263 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
264 	.scan_type = IIO_ST('u', (_bits), 16, 14 - (_bits)),	\
265 	.ext_info = ad5380_ext_info,				\
266 }
267 
268 static const struct ad5380_chip_info ad5380_chip_info_tbl[] = {
269 	[ID_AD5380_3] = {
270 		.channel_template = AD5380_CHANNEL(14),
271 		.num_channels = 40,
272 		.int_vref = 1250000,
273 	},
274 	[ID_AD5380_5] = {
275 		.channel_template = AD5380_CHANNEL(14),
276 		.num_channels = 40,
277 		.int_vref = 2500000,
278 	},
279 	[ID_AD5381_3] = {
280 		.channel_template = AD5380_CHANNEL(12),
281 		.num_channels = 16,
282 		.int_vref = 1250000,
283 	},
284 	[ID_AD5381_5] = {
285 		.channel_template = AD5380_CHANNEL(12),
286 		.num_channels = 16,
287 		.int_vref = 2500000,
288 	},
289 	[ID_AD5382_3] = {
290 		.channel_template = AD5380_CHANNEL(14),
291 		.num_channels = 32,
292 		.int_vref = 1250000,
293 	},
294 	[ID_AD5382_5] = {
295 		.channel_template = AD5380_CHANNEL(14),
296 		.num_channels = 32,
297 		.int_vref = 2500000,
298 	},
299 	[ID_AD5383_3] = {
300 		.channel_template = AD5380_CHANNEL(12),
301 		.num_channels = 32,
302 		.int_vref = 1250000,
303 	},
304 	[ID_AD5383_5] = {
305 		.channel_template = AD5380_CHANNEL(12),
306 		.num_channels = 32,
307 		.int_vref = 2500000,
308 	},
309 	[ID_AD5390_3] = {
310 		.channel_template = AD5380_CHANNEL(14),
311 		.num_channels = 16,
312 		.int_vref = 1250000,
313 	},
314 	[ID_AD5390_5] = {
315 		.channel_template = AD5380_CHANNEL(14),
316 		.num_channels = 16,
317 		.int_vref = 2500000,
318 	},
319 	[ID_AD5391_3] = {
320 		.channel_template = AD5380_CHANNEL(12),
321 		.num_channels = 16,
322 		.int_vref = 1250000,
323 	},
324 	[ID_AD5391_5] = {
325 		.channel_template = AD5380_CHANNEL(12),
326 		.num_channels = 16,
327 		.int_vref = 2500000,
328 	},
329 	[ID_AD5392_3] = {
330 		.channel_template = AD5380_CHANNEL(14),
331 		.num_channels = 8,
332 		.int_vref = 1250000,
333 	},
334 	[ID_AD5392_5] = {
335 		.channel_template = AD5380_CHANNEL(14),
336 		.num_channels = 8,
337 		.int_vref = 2500000,
338 	},
339 };
340 
341 static int ad5380_alloc_channels(struct iio_dev *indio_dev)
342 {
343 	struct ad5380_state *st = iio_priv(indio_dev);
344 	struct iio_chan_spec *channels;
345 	unsigned int i;
346 
347 	channels = kcalloc(st->chip_info->num_channels,
348 			   sizeof(struct iio_chan_spec), GFP_KERNEL);
349 
350 	if (!channels)
351 		return -ENOMEM;
352 
353 	for (i = 0; i < st->chip_info->num_channels; ++i) {
354 		channels[i] = st->chip_info->channel_template;
355 		channels[i].channel = i;
356 		channels[i].address = i;
357 	}
358 
359 	indio_dev->channels = channels;
360 
361 	return 0;
362 }
363 
364 static int ad5380_probe(struct device *dev, struct regmap *regmap,
365 			enum ad5380_type type, const char *name)
366 {
367 	struct iio_dev *indio_dev;
368 	struct ad5380_state *st;
369 	unsigned int ctrl = 0;
370 	int ret;
371 
372 	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
373 	if (indio_dev == NULL) {
374 		dev_err(dev, "Failed to allocate iio device\n");
375 		return -ENOMEM;
376 	}
377 
378 	st = iio_priv(indio_dev);
379 	dev_set_drvdata(dev, indio_dev);
380 
381 	st->chip_info = &ad5380_chip_info_tbl[type];
382 	st->regmap = regmap;
383 
384 	indio_dev->dev.parent = dev;
385 	indio_dev->name = name;
386 	indio_dev->info = &ad5380_info;
387 	indio_dev->modes = INDIO_DIRECT_MODE;
388 	indio_dev->num_channels = st->chip_info->num_channels;
389 
390 	ret = ad5380_alloc_channels(indio_dev);
391 	if (ret) {
392 		dev_err(dev, "Failed to allocate channel spec: %d\n", ret);
393 		return ret;
394 	}
395 
396 	if (st->chip_info->int_vref == 2500000)
397 		ctrl |= AD5380_CTRL_INT_VREF_2V5;
398 
399 	st->vref_reg = devm_regulator_get(dev, "vref");
400 	if (!IS_ERR(st->vref_reg)) {
401 		ret = regulator_enable(st->vref_reg);
402 		if (ret) {
403 			dev_err(dev, "Failed to enable vref regulators: %d\n",
404 				ret);
405 			goto error_free_reg;
406 		}
407 
408 		ret = regulator_get_voltage(st->vref_reg);
409 		if (ret < 0)
410 			goto error_disable_reg;
411 
412 		st->vref = ret;
413 	} else {
414 		st->vref = st->chip_info->int_vref;
415 		ctrl |= AD5380_CTRL_INT_VREF_EN;
416 	}
417 
418 	ret = regmap_write(st->regmap, AD5380_REG_SF_CTRL, ctrl);
419 	if (ret) {
420 		dev_err(dev, "Failed to write to device: %d\n", ret);
421 		goto error_disable_reg;
422 	}
423 
424 	ret = iio_device_register(indio_dev);
425 	if (ret) {
426 		dev_err(dev, "Failed to register iio device: %d\n", ret);
427 		goto error_disable_reg;
428 	}
429 
430 	return 0;
431 
432 error_disable_reg:
433 	if (!IS_ERR(st->vref_reg))
434 		regulator_disable(st->vref_reg);
435 error_free_reg:
436 	kfree(indio_dev->channels);
437 
438 	return ret;
439 }
440 
441 static int ad5380_remove(struct device *dev)
442 {
443 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
444 	struct ad5380_state *st = iio_priv(indio_dev);
445 
446 	iio_device_unregister(indio_dev);
447 
448 	kfree(indio_dev->channels);
449 
450 	if (!IS_ERR(st->vref_reg)) {
451 		regulator_disable(st->vref_reg);
452 	}
453 
454 	return 0;
455 }
456 
457 static bool ad5380_reg_false(struct device *dev, unsigned int reg)
458 {
459 	return false;
460 }
461 
462 static const struct regmap_config ad5380_regmap_config = {
463 	.reg_bits = 10,
464 	.val_bits = 14,
465 
466 	.max_register = AD5380_REG_DATA(40),
467 	.cache_type = REGCACHE_RBTREE,
468 
469 	.volatile_reg = ad5380_reg_false,
470 	.readable_reg = ad5380_reg_false,
471 };
472 
473 #if IS_ENABLED(CONFIG_SPI_MASTER)
474 
475 static int ad5380_spi_probe(struct spi_device *spi)
476 {
477 	const struct spi_device_id *id = spi_get_device_id(spi);
478 	struct regmap *regmap;
479 
480 	regmap = devm_regmap_init_spi(spi, &ad5380_regmap_config);
481 
482 	if (IS_ERR(regmap))
483 		return PTR_ERR(regmap);
484 
485 	return ad5380_probe(&spi->dev, regmap, id->driver_data, id->name);
486 }
487 
488 static int ad5380_spi_remove(struct spi_device *spi)
489 {
490 	return ad5380_remove(&spi->dev);
491 }
492 
493 static const struct spi_device_id ad5380_spi_ids[] = {
494 	{ "ad5380-3", ID_AD5380_3 },
495 	{ "ad5380-5", ID_AD5380_5 },
496 	{ "ad5381-3", ID_AD5381_3 },
497 	{ "ad5381-5", ID_AD5381_5 },
498 	{ "ad5382-3", ID_AD5382_3 },
499 	{ "ad5382-5", ID_AD5382_5 },
500 	{ "ad5383-3", ID_AD5383_3 },
501 	{ "ad5383-5", ID_AD5383_5 },
502 	{ "ad5384-3", ID_AD5380_3 },
503 	{ "ad5384-5", ID_AD5380_5 },
504 	{ "ad5390-3", ID_AD5390_3 },
505 	{ "ad5390-5", ID_AD5390_5 },
506 	{ "ad5391-3", ID_AD5391_3 },
507 	{ "ad5391-5", ID_AD5391_5 },
508 	{ "ad5392-3", ID_AD5392_3 },
509 	{ "ad5392-5", ID_AD5392_5 },
510 	{ }
511 };
512 MODULE_DEVICE_TABLE(spi, ad5380_spi_ids);
513 
514 static struct spi_driver ad5380_spi_driver = {
515 	.driver = {
516 		   .name = "ad5380",
517 		   .owner = THIS_MODULE,
518 	},
519 	.probe = ad5380_spi_probe,
520 	.remove = ad5380_spi_remove,
521 	.id_table = ad5380_spi_ids,
522 };
523 
524 static inline int ad5380_spi_register_driver(void)
525 {
526 	return spi_register_driver(&ad5380_spi_driver);
527 }
528 
529 static inline void ad5380_spi_unregister_driver(void)
530 {
531 	spi_unregister_driver(&ad5380_spi_driver);
532 }
533 
534 #else
535 
536 static inline int ad5380_spi_register_driver(void)
537 {
538 	return 0;
539 }
540 
541 static inline void ad5380_spi_unregister_driver(void)
542 {
543 }
544 
545 #endif
546 
547 #if IS_ENABLED(CONFIG_I2C)
548 
549 static int ad5380_i2c_probe(struct i2c_client *i2c,
550 			    const struct i2c_device_id *id)
551 {
552 	struct regmap *regmap;
553 
554 	regmap = devm_regmap_init_i2c(i2c, &ad5380_regmap_config);
555 
556 	if (IS_ERR(regmap))
557 		return PTR_ERR(regmap);
558 
559 	return ad5380_probe(&i2c->dev, regmap, id->driver_data, id->name);
560 }
561 
562 static int ad5380_i2c_remove(struct i2c_client *i2c)
563 {
564 	return ad5380_remove(&i2c->dev);
565 }
566 
567 static const struct i2c_device_id ad5380_i2c_ids[] = {
568 	{ "ad5380-3", ID_AD5380_3 },
569 	{ "ad5380-5", ID_AD5380_5 },
570 	{ "ad5381-3", ID_AD5381_3 },
571 	{ "ad5381-5", ID_AD5381_5 },
572 	{ "ad5382-3", ID_AD5382_3 },
573 	{ "ad5382-5", ID_AD5382_5 },
574 	{ "ad5383-3", ID_AD5383_3 },
575 	{ "ad5383-5", ID_AD5383_5 },
576 	{ "ad5384-3", ID_AD5380_3 },
577 	{ "ad5384-5", ID_AD5380_5 },
578 	{ "ad5390-3", ID_AD5390_3 },
579 	{ "ad5390-5", ID_AD5390_5 },
580 	{ "ad5391-3", ID_AD5391_3 },
581 	{ "ad5391-5", ID_AD5391_5 },
582 	{ "ad5392-3", ID_AD5392_3 },
583 	{ "ad5392-5", ID_AD5392_5 },
584 	{ }
585 };
586 MODULE_DEVICE_TABLE(i2c, ad5380_i2c_ids);
587 
588 static struct i2c_driver ad5380_i2c_driver = {
589 	.driver = {
590 		   .name = "ad5380",
591 		   .owner = THIS_MODULE,
592 	},
593 	.probe = ad5380_i2c_probe,
594 	.remove = ad5380_i2c_remove,
595 	.id_table = ad5380_i2c_ids,
596 };
597 
598 static inline int ad5380_i2c_register_driver(void)
599 {
600 	return i2c_add_driver(&ad5380_i2c_driver);
601 }
602 
603 static inline void ad5380_i2c_unregister_driver(void)
604 {
605 	i2c_del_driver(&ad5380_i2c_driver);
606 }
607 
608 #else
609 
610 static inline int ad5380_i2c_register_driver(void)
611 {
612 	return 0;
613 }
614 
615 static inline void ad5380_i2c_unregister_driver(void)
616 {
617 }
618 
619 #endif
620 
621 static int __init ad5380_spi_init(void)
622 {
623 	int ret;
624 
625 	ret = ad5380_spi_register_driver();
626 	if (ret)
627 		return ret;
628 
629 	ret = ad5380_i2c_register_driver();
630 	if (ret) {
631 		ad5380_spi_unregister_driver();
632 		return ret;
633 	}
634 
635 	return 0;
636 }
637 module_init(ad5380_spi_init);
638 
639 static void __exit ad5380_spi_exit(void)
640 {
641 	ad5380_i2c_unregister_driver();
642 	ad5380_spi_unregister_driver();
643 
644 }
645 module_exit(ad5380_spi_exit);
646 
647 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
648 MODULE_DESCRIPTION("Analog Devices AD5380/81/82/83/84/90/91/92 DAC");
649 MODULE_LICENSE("GPL v2");
650