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1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Analog devices AD5380, AD5381, AD5382, AD5383, AD5390, AD5391, AD5392
4  * multi-channel Digital to Analog Converters driver
5  *
6  * Copyright 2011 Analog Devices Inc.
7  */
8 
9 #include <linux/device.h>
10 #include <linux/err.h>
11 #include <linux/i2c.h>
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/spi/spi.h>
15 #include <linux/slab.h>
16 #include <linux/sysfs.h>
17 #include <linux/regmap.h>
18 #include <linux/regulator/consumer.h>
19 
20 #include <linux/iio/iio.h>
21 #include <linux/iio/sysfs.h>
22 
23 #define AD5380_REG_DATA(x)	(((x) << 2) | 3)
24 #define AD5380_REG_OFFSET(x)	(((x) << 2) | 2)
25 #define AD5380_REG_GAIN(x)	(((x) << 2) | 1)
26 #define AD5380_REG_SF_PWR_DOWN	(8 << 2)
27 #define AD5380_REG_SF_PWR_UP	(9 << 2)
28 #define AD5380_REG_SF_CTRL	(12 << 2)
29 
30 #define AD5380_CTRL_PWR_DOWN_MODE_OFFSET	13
31 #define AD5380_CTRL_INT_VREF_2V5		BIT(12)
32 #define AD5380_CTRL_INT_VREF_EN			BIT(10)
33 
34 /**
35  * struct ad5380_chip_info - chip specific information
36  * @channel_template:	channel specification template
37  * @num_channels:	number of channels
38  * @int_vref:		internal vref in uV
39 */
40 
41 struct ad5380_chip_info {
42 	struct iio_chan_spec	channel_template;
43 	unsigned int		num_channels;
44 	unsigned int		int_vref;
45 };
46 
47 /**
48  * struct ad5380_state - driver instance specific data
49  * @regmap:		regmap instance used by the device
50  * @chip_info:		chip model specific constants, available modes etc
51  * @vref_reg:		vref supply regulator
52  * @vref:		actual reference voltage used in uA
53  * @pwr_down:		whether the chip is currently in power down mode
54  * @lock:		lock to protect the data buffer during regmap ops
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 	struct mutex			lock;
64 };
65 
66 enum ad5380_type {
67 	ID_AD5380_3,
68 	ID_AD5380_5,
69 	ID_AD5381_3,
70 	ID_AD5381_5,
71 	ID_AD5382_3,
72 	ID_AD5382_5,
73 	ID_AD5383_3,
74 	ID_AD5383_5,
75 	ID_AD5390_3,
76 	ID_AD5390_5,
77 	ID_AD5391_3,
78 	ID_AD5391_5,
79 	ID_AD5392_3,
80 	ID_AD5392_5,
81 };
82 
ad5380_read_dac_powerdown(struct iio_dev * indio_dev,uintptr_t private,const struct iio_chan_spec * chan,char * buf)83 static ssize_t ad5380_read_dac_powerdown(struct iio_dev *indio_dev,
84 	uintptr_t private, const struct iio_chan_spec *chan, char *buf)
85 {
86 	struct ad5380_state *st = iio_priv(indio_dev);
87 
88 	return sprintf(buf, "%d\n", st->pwr_down);
89 }
90 
ad5380_write_dac_powerdown(struct iio_dev * indio_dev,uintptr_t private,const struct iio_chan_spec * chan,const char * buf,size_t len)91 static ssize_t ad5380_write_dac_powerdown(struct iio_dev *indio_dev,
92 	 uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
93 	 size_t len)
94 {
95 	struct ad5380_state *st = iio_priv(indio_dev);
96 	bool pwr_down;
97 	int ret;
98 
99 	ret = strtobool(buf, &pwr_down);
100 	if (ret)
101 		return ret;
102 
103 	mutex_lock(&st->lock);
104 
105 	if (pwr_down)
106 		ret = regmap_write(st->regmap, AD5380_REG_SF_PWR_DOWN, 0);
107 	else
108 		ret = regmap_write(st->regmap, AD5380_REG_SF_PWR_UP, 0);
109 
110 	st->pwr_down = pwr_down;
111 
112 	mutex_unlock(&st->lock);
113 
114 	return ret ? ret : len;
115 }
116 
117 static const char * const ad5380_powerdown_modes[] = {
118 	"100kohm_to_gnd",
119 	"three_state",
120 };
121 
ad5380_get_powerdown_mode(struct iio_dev * indio_dev,const struct iio_chan_spec * chan)122 static int ad5380_get_powerdown_mode(struct iio_dev *indio_dev,
123 	const struct iio_chan_spec *chan)
124 {
125 	struct ad5380_state *st = iio_priv(indio_dev);
126 	unsigned int mode;
127 	int ret;
128 
129 	ret = regmap_read(st->regmap, AD5380_REG_SF_CTRL, &mode);
130 	if (ret)
131 		return ret;
132 
133 	mode = (mode >> AD5380_CTRL_PWR_DOWN_MODE_OFFSET) & 1;
134 
135 	return mode;
136 }
137 
ad5380_set_powerdown_mode(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,unsigned int mode)138 static int ad5380_set_powerdown_mode(struct iio_dev *indio_dev,
139 	const struct iio_chan_spec *chan, unsigned int mode)
140 {
141 	struct ad5380_state *st = iio_priv(indio_dev);
142 	int ret;
143 
144 	ret = regmap_update_bits(st->regmap, AD5380_REG_SF_CTRL,
145 		1 << AD5380_CTRL_PWR_DOWN_MODE_OFFSET,
146 		mode << AD5380_CTRL_PWR_DOWN_MODE_OFFSET);
147 
148 	return ret;
149 }
150 
151 static const struct iio_enum ad5380_powerdown_mode_enum = {
152 	.items = ad5380_powerdown_modes,
153 	.num_items = ARRAY_SIZE(ad5380_powerdown_modes),
154 	.get = ad5380_get_powerdown_mode,
155 	.set = ad5380_set_powerdown_mode,
156 };
157 
ad5380_info_to_reg(struct iio_chan_spec const * chan,long info)158 static unsigned int ad5380_info_to_reg(struct iio_chan_spec const *chan,
159 	long info)
160 {
161 	switch (info) {
162 	case IIO_CHAN_INFO_RAW:
163 		return AD5380_REG_DATA(chan->address);
164 	case IIO_CHAN_INFO_CALIBBIAS:
165 		return AD5380_REG_OFFSET(chan->address);
166 	case IIO_CHAN_INFO_CALIBSCALE:
167 		return AD5380_REG_GAIN(chan->address);
168 	default:
169 		break;
170 	}
171 
172 	return 0;
173 }
174 
ad5380_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long info)175 static int ad5380_write_raw(struct iio_dev *indio_dev,
176 	struct iio_chan_spec const *chan, int val, int val2, long info)
177 {
178 	const unsigned int max_val = (1 << chan->scan_type.realbits);
179 	struct ad5380_state *st = iio_priv(indio_dev);
180 
181 	switch (info) {
182 	case IIO_CHAN_INFO_RAW:
183 	case IIO_CHAN_INFO_CALIBSCALE:
184 		if (val >= max_val || val < 0)
185 			return -EINVAL;
186 
187 		return regmap_write(st->regmap,
188 			ad5380_info_to_reg(chan, info),
189 			val << chan->scan_type.shift);
190 	case IIO_CHAN_INFO_CALIBBIAS:
191 		val += (1 << chan->scan_type.realbits) / 2;
192 		if (val >= max_val || val < 0)
193 			return -EINVAL;
194 
195 		return regmap_write(st->regmap,
196 			AD5380_REG_OFFSET(chan->address),
197 			val << chan->scan_type.shift);
198 	default:
199 		break;
200 	}
201 	return -EINVAL;
202 }
203 
ad5380_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long info)204 static int ad5380_read_raw(struct iio_dev *indio_dev,
205 	struct iio_chan_spec const *chan, int *val, int *val2, long info)
206 {
207 	struct ad5380_state *st = iio_priv(indio_dev);
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 		*val = 2 * st->vref;
229 		*val2 = chan->scan_type.realbits;
230 		return IIO_VAL_FRACTIONAL_LOG2;
231 	default:
232 		break;
233 	}
234 
235 	return -EINVAL;
236 }
237 
238 static const struct iio_info ad5380_info = {
239 	.read_raw = ad5380_read_raw,
240 	.write_raw = ad5380_write_raw,
241 };
242 
243 static const struct iio_chan_spec_ext_info ad5380_ext_info[] = {
244 	{
245 		.name = "powerdown",
246 		.read = ad5380_read_dac_powerdown,
247 		.write = ad5380_write_dac_powerdown,
248 		.shared = IIO_SEPARATE,
249 	},
250 	IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE,
251 		 &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 = {						\
265 		.sign = 'u',					\
266 		.realbits = (_bits),				\
267 		.storagebits =  16,				\
268 		.shift = 14 - (_bits),				\
269 	},							\
270 	.ext_info = ad5380_ext_info,				\
271 }
272 
273 static const struct ad5380_chip_info ad5380_chip_info_tbl[] = {
274 	[ID_AD5380_3] = {
275 		.channel_template = AD5380_CHANNEL(14),
276 		.num_channels = 40,
277 		.int_vref = 1250,
278 	},
279 	[ID_AD5380_5] = {
280 		.channel_template = AD5380_CHANNEL(14),
281 		.num_channels = 40,
282 		.int_vref = 2500,
283 	},
284 	[ID_AD5381_3] = {
285 		.channel_template = AD5380_CHANNEL(12),
286 		.num_channels = 16,
287 		.int_vref = 1250,
288 	},
289 	[ID_AD5381_5] = {
290 		.channel_template = AD5380_CHANNEL(12),
291 		.num_channels = 16,
292 		.int_vref = 2500,
293 	},
294 	[ID_AD5382_3] = {
295 		.channel_template = AD5380_CHANNEL(14),
296 		.num_channels = 32,
297 		.int_vref = 1250,
298 	},
299 	[ID_AD5382_5] = {
300 		.channel_template = AD5380_CHANNEL(14),
301 		.num_channels = 32,
302 		.int_vref = 2500,
303 	},
304 	[ID_AD5383_3] = {
305 		.channel_template = AD5380_CHANNEL(12),
306 		.num_channels = 32,
307 		.int_vref = 1250,
308 	},
309 	[ID_AD5383_5] = {
310 		.channel_template = AD5380_CHANNEL(12),
311 		.num_channels = 32,
312 		.int_vref = 2500,
313 	},
314 	[ID_AD5390_3] = {
315 		.channel_template = AD5380_CHANNEL(14),
316 		.num_channels = 16,
317 		.int_vref = 1250,
318 	},
319 	[ID_AD5390_5] = {
320 		.channel_template = AD5380_CHANNEL(14),
321 		.num_channels = 16,
322 		.int_vref = 2500,
323 	},
324 	[ID_AD5391_3] = {
325 		.channel_template = AD5380_CHANNEL(12),
326 		.num_channels = 16,
327 		.int_vref = 1250,
328 	},
329 	[ID_AD5391_5] = {
330 		.channel_template = AD5380_CHANNEL(12),
331 		.num_channels = 16,
332 		.int_vref = 2500,
333 	},
334 	[ID_AD5392_3] = {
335 		.channel_template = AD5380_CHANNEL(14),
336 		.num_channels = 8,
337 		.int_vref = 1250,
338 	},
339 	[ID_AD5392_5] = {
340 		.channel_template = AD5380_CHANNEL(14),
341 		.num_channels = 8,
342 		.int_vref = 2500,
343 	},
344 };
345 
ad5380_alloc_channels(struct iio_dev * indio_dev)346 static int ad5380_alloc_channels(struct iio_dev *indio_dev)
347 {
348 	struct ad5380_state *st = iio_priv(indio_dev);
349 	struct iio_chan_spec *channels;
350 	unsigned int i;
351 
352 	channels = kcalloc(st->chip_info->num_channels,
353 			   sizeof(struct iio_chan_spec), GFP_KERNEL);
354 
355 	if (!channels)
356 		return -ENOMEM;
357 
358 	for (i = 0; i < st->chip_info->num_channels; ++i) {
359 		channels[i] = st->chip_info->channel_template;
360 		channels[i].channel = i;
361 		channels[i].address = i;
362 	}
363 
364 	indio_dev->channels = channels;
365 
366 	return 0;
367 }
368 
ad5380_probe(struct device * dev,struct regmap * regmap,enum ad5380_type type,const char * name)369 static int ad5380_probe(struct device *dev, struct regmap *regmap,
370 			enum ad5380_type type, const char *name)
371 {
372 	struct iio_dev *indio_dev;
373 	struct ad5380_state *st;
374 	unsigned int ctrl = 0;
375 	int ret;
376 
377 	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
378 	if (indio_dev == NULL) {
379 		dev_err(dev, "Failed to allocate iio device\n");
380 		return -ENOMEM;
381 	}
382 
383 	st = iio_priv(indio_dev);
384 	dev_set_drvdata(dev, indio_dev);
385 
386 	st->chip_info = &ad5380_chip_info_tbl[type];
387 	st->regmap = regmap;
388 
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 	mutex_init(&st->lock);
395 
396 	ret = ad5380_alloc_channels(indio_dev);
397 	if (ret) {
398 		dev_err(dev, "Failed to allocate channel spec: %d\n", ret);
399 		return ret;
400 	}
401 
402 	if (st->chip_info->int_vref == 2500)
403 		ctrl |= AD5380_CTRL_INT_VREF_2V5;
404 
405 	st->vref_reg = devm_regulator_get(dev, "vref");
406 	if (!IS_ERR(st->vref_reg)) {
407 		ret = regulator_enable(st->vref_reg);
408 		if (ret) {
409 			dev_err(dev, "Failed to enable vref regulators: %d\n",
410 				ret);
411 			goto error_free_reg;
412 		}
413 
414 		ret = regulator_get_voltage(st->vref_reg);
415 		if (ret < 0)
416 			goto error_disable_reg;
417 
418 		st->vref = ret / 1000;
419 	} else {
420 		st->vref = st->chip_info->int_vref;
421 		ctrl |= AD5380_CTRL_INT_VREF_EN;
422 	}
423 
424 	ret = regmap_write(st->regmap, AD5380_REG_SF_CTRL, ctrl);
425 	if (ret) {
426 		dev_err(dev, "Failed to write to device: %d\n", ret);
427 		goto error_disable_reg;
428 	}
429 
430 	ret = iio_device_register(indio_dev);
431 	if (ret) {
432 		dev_err(dev, "Failed to register iio device: %d\n", ret);
433 		goto error_disable_reg;
434 	}
435 
436 	return 0;
437 
438 error_disable_reg:
439 	if (!IS_ERR(st->vref_reg))
440 		regulator_disable(st->vref_reg);
441 error_free_reg:
442 	kfree(indio_dev->channels);
443 
444 	return ret;
445 }
446 
ad5380_remove(struct device * dev)447 static int ad5380_remove(struct device *dev)
448 {
449 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
450 	struct ad5380_state *st = iio_priv(indio_dev);
451 
452 	iio_device_unregister(indio_dev);
453 
454 	kfree(indio_dev->channels);
455 
456 	if (!IS_ERR(st->vref_reg)) {
457 		regulator_disable(st->vref_reg);
458 	}
459 
460 	return 0;
461 }
462 
ad5380_reg_false(struct device * dev,unsigned int reg)463 static bool ad5380_reg_false(struct device *dev, unsigned int reg)
464 {
465 	return false;
466 }
467 
468 static const struct regmap_config ad5380_regmap_config = {
469 	.reg_bits = 10,
470 	.val_bits = 14,
471 
472 	.max_register = AD5380_REG_DATA(40),
473 	.cache_type = REGCACHE_RBTREE,
474 
475 	.volatile_reg = ad5380_reg_false,
476 	.readable_reg = ad5380_reg_false,
477 };
478 
479 #if IS_ENABLED(CONFIG_SPI_MASTER)
480 
ad5380_spi_probe(struct spi_device * spi)481 static int ad5380_spi_probe(struct spi_device *spi)
482 {
483 	const struct spi_device_id *id = spi_get_device_id(spi);
484 	struct regmap *regmap;
485 
486 	regmap = devm_regmap_init_spi(spi, &ad5380_regmap_config);
487 
488 	if (IS_ERR(regmap))
489 		return PTR_ERR(regmap);
490 
491 	return ad5380_probe(&spi->dev, regmap, id->driver_data, id->name);
492 }
493 
ad5380_spi_remove(struct spi_device * spi)494 static int ad5380_spi_remove(struct spi_device *spi)
495 {
496 	return ad5380_remove(&spi->dev);
497 }
498 
499 static const struct spi_device_id ad5380_spi_ids[] = {
500 	{ "ad5380-3", ID_AD5380_3 },
501 	{ "ad5380-5", ID_AD5380_5 },
502 	{ "ad5381-3", ID_AD5381_3 },
503 	{ "ad5381-5", ID_AD5381_5 },
504 	{ "ad5382-3", ID_AD5382_3 },
505 	{ "ad5382-5", ID_AD5382_5 },
506 	{ "ad5383-3", ID_AD5383_3 },
507 	{ "ad5383-5", ID_AD5383_5 },
508 	{ "ad5384-3", ID_AD5380_3 },
509 	{ "ad5384-5", ID_AD5380_5 },
510 	{ "ad5390-3", ID_AD5390_3 },
511 	{ "ad5390-5", ID_AD5390_5 },
512 	{ "ad5391-3", ID_AD5391_3 },
513 	{ "ad5391-5", ID_AD5391_5 },
514 	{ "ad5392-3", ID_AD5392_3 },
515 	{ "ad5392-5", ID_AD5392_5 },
516 	{ }
517 };
518 MODULE_DEVICE_TABLE(spi, ad5380_spi_ids);
519 
520 static struct spi_driver ad5380_spi_driver = {
521 	.driver = {
522 		   .name = "ad5380",
523 	},
524 	.probe = ad5380_spi_probe,
525 	.remove = ad5380_spi_remove,
526 	.id_table = ad5380_spi_ids,
527 };
528 
ad5380_spi_register_driver(void)529 static inline int ad5380_spi_register_driver(void)
530 {
531 	return spi_register_driver(&ad5380_spi_driver);
532 }
533 
ad5380_spi_unregister_driver(void)534 static inline void ad5380_spi_unregister_driver(void)
535 {
536 	spi_unregister_driver(&ad5380_spi_driver);
537 }
538 
539 #else
540 
ad5380_spi_register_driver(void)541 static inline int ad5380_spi_register_driver(void)
542 {
543 	return 0;
544 }
545 
ad5380_spi_unregister_driver(void)546 static inline void ad5380_spi_unregister_driver(void)
547 {
548 }
549 
550 #endif
551 
552 #if IS_ENABLED(CONFIG_I2C)
553 
ad5380_i2c_probe(struct i2c_client * i2c,const struct i2c_device_id * id)554 static int ad5380_i2c_probe(struct i2c_client *i2c,
555 			    const struct i2c_device_id *id)
556 {
557 	struct regmap *regmap;
558 
559 	regmap = devm_regmap_init_i2c(i2c, &ad5380_regmap_config);
560 
561 	if (IS_ERR(regmap))
562 		return PTR_ERR(regmap);
563 
564 	return ad5380_probe(&i2c->dev, regmap, id->driver_data, id->name);
565 }
566 
ad5380_i2c_remove(struct i2c_client * i2c)567 static int ad5380_i2c_remove(struct i2c_client *i2c)
568 {
569 	return ad5380_remove(&i2c->dev);
570 }
571 
572 static const struct i2c_device_id ad5380_i2c_ids[] = {
573 	{ "ad5380-3", ID_AD5380_3 },
574 	{ "ad5380-5", ID_AD5380_5 },
575 	{ "ad5381-3", ID_AD5381_3 },
576 	{ "ad5381-5", ID_AD5381_5 },
577 	{ "ad5382-3", ID_AD5382_3 },
578 	{ "ad5382-5", ID_AD5382_5 },
579 	{ "ad5383-3", ID_AD5383_3 },
580 	{ "ad5383-5", ID_AD5383_5 },
581 	{ "ad5384-3", ID_AD5380_3 },
582 	{ "ad5384-5", ID_AD5380_5 },
583 	{ "ad5390-3", ID_AD5390_3 },
584 	{ "ad5390-5", ID_AD5390_5 },
585 	{ "ad5391-3", ID_AD5391_3 },
586 	{ "ad5391-5", ID_AD5391_5 },
587 	{ "ad5392-3", ID_AD5392_3 },
588 	{ "ad5392-5", ID_AD5392_5 },
589 	{ }
590 };
591 MODULE_DEVICE_TABLE(i2c, ad5380_i2c_ids);
592 
593 static struct i2c_driver ad5380_i2c_driver = {
594 	.driver = {
595 		   .name = "ad5380",
596 	},
597 	.probe = ad5380_i2c_probe,
598 	.remove = ad5380_i2c_remove,
599 	.id_table = ad5380_i2c_ids,
600 };
601 
ad5380_i2c_register_driver(void)602 static inline int ad5380_i2c_register_driver(void)
603 {
604 	return i2c_add_driver(&ad5380_i2c_driver);
605 }
606 
ad5380_i2c_unregister_driver(void)607 static inline void ad5380_i2c_unregister_driver(void)
608 {
609 	i2c_del_driver(&ad5380_i2c_driver);
610 }
611 
612 #else
613 
ad5380_i2c_register_driver(void)614 static inline int ad5380_i2c_register_driver(void)
615 {
616 	return 0;
617 }
618 
ad5380_i2c_unregister_driver(void)619 static inline void ad5380_i2c_unregister_driver(void)
620 {
621 }
622 
623 #endif
624 
ad5380_spi_init(void)625 static int __init ad5380_spi_init(void)
626 {
627 	int ret;
628 
629 	ret = ad5380_spi_register_driver();
630 	if (ret)
631 		return ret;
632 
633 	ret = ad5380_i2c_register_driver();
634 	if (ret) {
635 		ad5380_spi_unregister_driver();
636 		return ret;
637 	}
638 
639 	return 0;
640 }
641 module_init(ad5380_spi_init);
642 
ad5380_spi_exit(void)643 static void __exit ad5380_spi_exit(void)
644 {
645 	ad5380_i2c_unregister_driver();
646 	ad5380_spi_unregister_driver();
647 
648 }
649 module_exit(ad5380_spi_exit);
650 
651 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
652 MODULE_DESCRIPTION("Analog Devices AD5380/81/82/83/84/90/91/92 DAC");
653 MODULE_LICENSE("GPL v2");
654