1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * AD5446 SPI DAC driver
4  *
5  * Copyright 2010 Analog Devices Inc.
6  */
7 
8 #include <linux/interrupt.h>
9 #include <linux/workqueue.h>
10 #include <linux/device.h>
11 #include <linux/kernel.h>
12 #include <linux/slab.h>
13 #include <linux/sysfs.h>
14 #include <linux/list.h>
15 #include <linux/spi/spi.h>
16 #include <linux/i2c.h>
17 #include <linux/regulator/consumer.h>
18 #include <linux/err.h>
19 #include <linux/module.h>
20 #include <linux/mod_devicetable.h>
21 
22 #include <linux/iio/iio.h>
23 #include <linux/iio/sysfs.h>
24 
25 #include <asm/unaligned.h>
26 
27 #define MODE_PWRDWN_1k		0x1
28 #define MODE_PWRDWN_100k	0x2
29 #define MODE_PWRDWN_TRISTATE	0x3
30 
31 /**
32  * struct ad5446_state - driver instance specific data
33  * @dev:		this device
34  * @chip_info:		chip model specific constants, available modes etc
35  * @reg:		supply regulator
36  * @vref_mv:		actual reference voltage used
37  * @cached_val:		store/retrieve values during power down
38  * @pwr_down_mode:	power down mode (1k, 100k or tristate)
39  * @pwr_down:		true if the device is in power down
40  * @lock:		lock to protect the data buffer during write ops
41  */
42 
43 struct ad5446_state {
44 	struct device		*dev;
45 	const struct ad5446_chip_info	*chip_info;
46 	struct regulator		*reg;
47 	unsigned short			vref_mv;
48 	unsigned			cached_val;
49 	unsigned			pwr_down_mode;
50 	unsigned			pwr_down;
51 	struct mutex			lock;
52 };
53 
54 /**
55  * struct ad5446_chip_info - chip specific information
56  * @channel:		channel spec for the DAC
57  * @int_vref_mv:	AD5620/40/60: the internal reference voltage
58  * @write:		chip specific helper function to write to the register
59  */
60 
61 struct ad5446_chip_info {
62 	struct iio_chan_spec	channel;
63 	u16			int_vref_mv;
64 	int			(*write)(struct ad5446_state *st, unsigned val);
65 };
66 
67 static const char * const ad5446_powerdown_modes[] = {
68 	"1kohm_to_gnd", "100kohm_to_gnd", "three_state"
69 };
70 
ad5446_set_powerdown_mode(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,unsigned int mode)71 static int ad5446_set_powerdown_mode(struct iio_dev *indio_dev,
72 	const struct iio_chan_spec *chan, unsigned int mode)
73 {
74 	struct ad5446_state *st = iio_priv(indio_dev);
75 
76 	st->pwr_down_mode = mode + 1;
77 
78 	return 0;
79 }
80 
ad5446_get_powerdown_mode(struct iio_dev * indio_dev,const struct iio_chan_spec * chan)81 static int ad5446_get_powerdown_mode(struct iio_dev *indio_dev,
82 	const struct iio_chan_spec *chan)
83 {
84 	struct ad5446_state *st = iio_priv(indio_dev);
85 
86 	return st->pwr_down_mode - 1;
87 }
88 
89 static const struct iio_enum ad5446_powerdown_mode_enum = {
90 	.items = ad5446_powerdown_modes,
91 	.num_items = ARRAY_SIZE(ad5446_powerdown_modes),
92 	.get = ad5446_get_powerdown_mode,
93 	.set = ad5446_set_powerdown_mode,
94 };
95 
ad5446_read_dac_powerdown(struct iio_dev * indio_dev,uintptr_t private,const struct iio_chan_spec * chan,char * buf)96 static ssize_t ad5446_read_dac_powerdown(struct iio_dev *indio_dev,
97 					   uintptr_t private,
98 					   const struct iio_chan_spec *chan,
99 					   char *buf)
100 {
101 	struct ad5446_state *st = iio_priv(indio_dev);
102 
103 	return sysfs_emit(buf, "%d\n", st->pwr_down);
104 }
105 
ad5446_write_dac_powerdown(struct iio_dev * indio_dev,uintptr_t private,const struct iio_chan_spec * chan,const char * buf,size_t len)106 static ssize_t ad5446_write_dac_powerdown(struct iio_dev *indio_dev,
107 					    uintptr_t private,
108 					    const struct iio_chan_spec *chan,
109 					    const char *buf, size_t len)
110 {
111 	struct ad5446_state *st = iio_priv(indio_dev);
112 	unsigned int shift;
113 	unsigned int val;
114 	bool powerdown;
115 	int ret;
116 
117 	ret = kstrtobool(buf, &powerdown);
118 	if (ret)
119 		return ret;
120 
121 	mutex_lock(&st->lock);
122 	st->pwr_down = powerdown;
123 
124 	if (st->pwr_down) {
125 		shift = chan->scan_type.realbits + chan->scan_type.shift;
126 		val = st->pwr_down_mode << shift;
127 	} else {
128 		val = st->cached_val;
129 	}
130 
131 	ret = st->chip_info->write(st, val);
132 	mutex_unlock(&st->lock);
133 
134 	return ret ? ret : len;
135 }
136 
137 static const struct iio_chan_spec_ext_info ad5446_ext_info_powerdown[] = {
138 	{
139 		.name = "powerdown",
140 		.read = ad5446_read_dac_powerdown,
141 		.write = ad5446_write_dac_powerdown,
142 		.shared = IIO_SEPARATE,
143 	},
144 	IIO_ENUM("powerdown_mode", IIO_SEPARATE, &ad5446_powerdown_mode_enum),
145 	IIO_ENUM_AVAILABLE("powerdown_mode", IIO_SHARED_BY_TYPE, &ad5446_powerdown_mode_enum),
146 	{ },
147 };
148 
149 #define _AD5446_CHANNEL(bits, storage, _shift, ext) { \
150 	.type = IIO_VOLTAGE, \
151 	.indexed = 1, \
152 	.output = 1, \
153 	.channel = 0, \
154 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
155 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
156 	.scan_type = { \
157 		.sign = 'u', \
158 		.realbits = (bits), \
159 		.storagebits = (storage), \
160 		.shift = (_shift), \
161 		}, \
162 	.ext_info = (ext), \
163 }
164 
165 #define AD5446_CHANNEL(bits, storage, shift) \
166 	_AD5446_CHANNEL(bits, storage, shift, NULL)
167 
168 #define AD5446_CHANNEL_POWERDOWN(bits, storage, shift) \
169 	_AD5446_CHANNEL(bits, storage, shift, ad5446_ext_info_powerdown)
170 
ad5446_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long m)171 static int ad5446_read_raw(struct iio_dev *indio_dev,
172 			   struct iio_chan_spec const *chan,
173 			   int *val,
174 			   int *val2,
175 			   long m)
176 {
177 	struct ad5446_state *st = iio_priv(indio_dev);
178 
179 	switch (m) {
180 	case IIO_CHAN_INFO_RAW:
181 		*val = st->cached_val >> chan->scan_type.shift;
182 		return IIO_VAL_INT;
183 	case IIO_CHAN_INFO_SCALE:
184 		*val = st->vref_mv;
185 		*val2 = chan->scan_type.realbits;
186 		return IIO_VAL_FRACTIONAL_LOG2;
187 	}
188 	return -EINVAL;
189 }
190 
ad5446_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)191 static int ad5446_write_raw(struct iio_dev *indio_dev,
192 			       struct iio_chan_spec const *chan,
193 			       int val,
194 			       int val2,
195 			       long mask)
196 {
197 	struct ad5446_state *st = iio_priv(indio_dev);
198 	int ret = 0;
199 
200 	switch (mask) {
201 	case IIO_CHAN_INFO_RAW:
202 		if (val >= (1 << chan->scan_type.realbits) || val < 0)
203 			return -EINVAL;
204 
205 		val <<= chan->scan_type.shift;
206 		mutex_lock(&st->lock);
207 		st->cached_val = val;
208 		if (!st->pwr_down)
209 			ret = st->chip_info->write(st, val);
210 		mutex_unlock(&st->lock);
211 		break;
212 	default:
213 		ret = -EINVAL;
214 	}
215 
216 	return ret;
217 }
218 
219 static const struct iio_info ad5446_info = {
220 	.read_raw = ad5446_read_raw,
221 	.write_raw = ad5446_write_raw,
222 };
223 
ad5446_probe(struct device * dev,const char * name,const struct ad5446_chip_info * chip_info)224 static int ad5446_probe(struct device *dev, const char *name,
225 			const struct ad5446_chip_info *chip_info)
226 {
227 	struct ad5446_state *st;
228 	struct iio_dev *indio_dev;
229 	struct regulator *reg;
230 	int ret, voltage_uv = 0;
231 
232 	reg = devm_regulator_get(dev, "vcc");
233 	if (!IS_ERR(reg)) {
234 		ret = regulator_enable(reg);
235 		if (ret)
236 			return ret;
237 
238 		ret = regulator_get_voltage(reg);
239 		if (ret < 0)
240 			goto error_disable_reg;
241 
242 		voltage_uv = ret;
243 	}
244 
245 	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
246 	if (indio_dev == NULL) {
247 		ret = -ENOMEM;
248 		goto error_disable_reg;
249 	}
250 	st = iio_priv(indio_dev);
251 	st->chip_info = chip_info;
252 
253 	dev_set_drvdata(dev, indio_dev);
254 	st->reg = reg;
255 	st->dev = dev;
256 
257 	indio_dev->name = name;
258 	indio_dev->info = &ad5446_info;
259 	indio_dev->modes = INDIO_DIRECT_MODE;
260 	indio_dev->channels = &st->chip_info->channel;
261 	indio_dev->num_channels = 1;
262 
263 	mutex_init(&st->lock);
264 
265 	st->pwr_down_mode = MODE_PWRDWN_1k;
266 
267 	if (st->chip_info->int_vref_mv)
268 		st->vref_mv = st->chip_info->int_vref_mv;
269 	else if (voltage_uv)
270 		st->vref_mv = voltage_uv / 1000;
271 	else
272 		dev_warn(dev, "reference voltage unspecified\n");
273 
274 	ret = iio_device_register(indio_dev);
275 	if (ret)
276 		goto error_disable_reg;
277 
278 	return 0;
279 
280 error_disable_reg:
281 	if (!IS_ERR(reg))
282 		regulator_disable(reg);
283 	return ret;
284 }
285 
ad5446_remove(struct device * dev)286 static void ad5446_remove(struct device *dev)
287 {
288 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
289 	struct ad5446_state *st = iio_priv(indio_dev);
290 
291 	iio_device_unregister(indio_dev);
292 	if (!IS_ERR(st->reg))
293 		regulator_disable(st->reg);
294 }
295 
296 #if IS_ENABLED(CONFIG_SPI_MASTER)
297 
ad5446_write(struct ad5446_state * st,unsigned val)298 static int ad5446_write(struct ad5446_state *st, unsigned val)
299 {
300 	struct spi_device *spi = to_spi_device(st->dev);
301 	__be16 data = cpu_to_be16(val);
302 
303 	return spi_write(spi, &data, sizeof(data));
304 }
305 
ad5660_write(struct ad5446_state * st,unsigned val)306 static int ad5660_write(struct ad5446_state *st, unsigned val)
307 {
308 	struct spi_device *spi = to_spi_device(st->dev);
309 	uint8_t data[3];
310 
311 	put_unaligned_be24(val, &data[0]);
312 
313 	return spi_write(spi, data, sizeof(data));
314 }
315 
316 /*
317  * ad5446_supported_spi_device_ids:
318  * The AD5620/40/60 parts are available in different fixed internal reference
319  * voltage options. The actual part numbers may look differently
320  * (and a bit cryptic), however this style is used to make clear which
321  * parts are supported here.
322  */
323 enum ad5446_supported_spi_device_ids {
324 	ID_AD5300,
325 	ID_AD5310,
326 	ID_AD5320,
327 	ID_AD5444,
328 	ID_AD5446,
329 	ID_AD5450,
330 	ID_AD5451,
331 	ID_AD5541A,
332 	ID_AD5512A,
333 	ID_AD5553,
334 	ID_AD5600,
335 	ID_AD5601,
336 	ID_AD5611,
337 	ID_AD5621,
338 	ID_AD5641,
339 	ID_AD5620_2500,
340 	ID_AD5620_1250,
341 	ID_AD5640_2500,
342 	ID_AD5640_1250,
343 	ID_AD5660_2500,
344 	ID_AD5660_1250,
345 	ID_AD5662,
346 };
347 
348 static const struct ad5446_chip_info ad5446_spi_chip_info[] = {
349 	[ID_AD5300] = {
350 		.channel = AD5446_CHANNEL_POWERDOWN(8, 16, 4),
351 		.write = ad5446_write,
352 	},
353 	[ID_AD5310] = {
354 		.channel = AD5446_CHANNEL_POWERDOWN(10, 16, 2),
355 		.write = ad5446_write,
356 	},
357 	[ID_AD5320] = {
358 		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 0),
359 		.write = ad5446_write,
360 	},
361 	[ID_AD5444] = {
362 		.channel = AD5446_CHANNEL(12, 16, 2),
363 		.write = ad5446_write,
364 	},
365 	[ID_AD5446] = {
366 		.channel = AD5446_CHANNEL(14, 16, 0),
367 		.write = ad5446_write,
368 	},
369 	[ID_AD5450] = {
370 		.channel = AD5446_CHANNEL(8, 16, 6),
371 		.write = ad5446_write,
372 	},
373 	[ID_AD5451] = {
374 		.channel = AD5446_CHANNEL(10, 16, 4),
375 		.write = ad5446_write,
376 	},
377 	[ID_AD5541A] = {
378 		.channel = AD5446_CHANNEL(16, 16, 0),
379 		.write = ad5446_write,
380 	},
381 	[ID_AD5512A] = {
382 		.channel = AD5446_CHANNEL(12, 16, 4),
383 		.write = ad5446_write,
384 	},
385 	[ID_AD5553] = {
386 		.channel = AD5446_CHANNEL(14, 16, 0),
387 		.write = ad5446_write,
388 	},
389 	[ID_AD5600] = {
390 		.channel = AD5446_CHANNEL(16, 16, 0),
391 		.write = ad5446_write,
392 	},
393 	[ID_AD5601] = {
394 		.channel = AD5446_CHANNEL_POWERDOWN(8, 16, 6),
395 		.write = ad5446_write,
396 	},
397 	[ID_AD5611] = {
398 		.channel = AD5446_CHANNEL_POWERDOWN(10, 16, 4),
399 		.write = ad5446_write,
400 	},
401 	[ID_AD5621] = {
402 		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 2),
403 		.write = ad5446_write,
404 	},
405 	[ID_AD5641] = {
406 		.channel = AD5446_CHANNEL_POWERDOWN(14, 16, 0),
407 		.write = ad5446_write,
408 	},
409 	[ID_AD5620_2500] = {
410 		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 2),
411 		.int_vref_mv = 2500,
412 		.write = ad5446_write,
413 	},
414 	[ID_AD5620_1250] = {
415 		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 2),
416 		.int_vref_mv = 1250,
417 		.write = ad5446_write,
418 	},
419 	[ID_AD5640_2500] = {
420 		.channel = AD5446_CHANNEL_POWERDOWN(14, 16, 0),
421 		.int_vref_mv = 2500,
422 		.write = ad5446_write,
423 	},
424 	[ID_AD5640_1250] = {
425 		.channel = AD5446_CHANNEL_POWERDOWN(14, 16, 0),
426 		.int_vref_mv = 1250,
427 		.write = ad5446_write,
428 	},
429 	[ID_AD5660_2500] = {
430 		.channel = AD5446_CHANNEL_POWERDOWN(16, 16, 0),
431 		.int_vref_mv = 2500,
432 		.write = ad5660_write,
433 	},
434 	[ID_AD5660_1250] = {
435 		.channel = AD5446_CHANNEL_POWERDOWN(16, 16, 0),
436 		.int_vref_mv = 1250,
437 		.write = ad5660_write,
438 	},
439 	[ID_AD5662] = {
440 		.channel = AD5446_CHANNEL_POWERDOWN(16, 16, 0),
441 		.write = ad5660_write,
442 	},
443 };
444 
445 static const struct spi_device_id ad5446_spi_ids[] = {
446 	{"ad5300", ID_AD5300},
447 	{"ad5310", ID_AD5310},
448 	{"ad5320", ID_AD5320},
449 	{"ad5444", ID_AD5444},
450 	{"ad5446", ID_AD5446},
451 	{"ad5450", ID_AD5450},
452 	{"ad5451", ID_AD5451},
453 	{"ad5452", ID_AD5444}, /* ad5452 is compatible to the ad5444 */
454 	{"ad5453", ID_AD5446}, /* ad5453 is compatible to the ad5446 */
455 	{"ad5512a", ID_AD5512A},
456 	{"ad5541a", ID_AD5541A},
457 	{"ad5542a", ID_AD5541A}, /* ad5541a and ad5542a are compatible */
458 	{"ad5543", ID_AD5541A}, /* ad5541a and ad5543 are compatible */
459 	{"ad5553", ID_AD5553},
460 	{"ad5600", ID_AD5600},
461 	{"ad5601", ID_AD5601},
462 	{"ad5611", ID_AD5611},
463 	{"ad5621", ID_AD5621},
464 	{"ad5641", ID_AD5641},
465 	{"ad5620-2500", ID_AD5620_2500}, /* AD5620/40/60: */
466 	{"ad5620-1250", ID_AD5620_1250}, /* part numbers may look differently */
467 	{"ad5640-2500", ID_AD5640_2500},
468 	{"ad5640-1250", ID_AD5640_1250},
469 	{"ad5660-2500", ID_AD5660_2500},
470 	{"ad5660-1250", ID_AD5660_1250},
471 	{"ad5662", ID_AD5662},
472 	{"dac081s101", ID_AD5300}, /* compatible Texas Instruments chips */
473 	{"dac101s101", ID_AD5310},
474 	{"dac121s101", ID_AD5320},
475 	{"dac7512", ID_AD5320},
476 	{}
477 };
478 MODULE_DEVICE_TABLE(spi, ad5446_spi_ids);
479 
480 static const struct of_device_id ad5446_of_ids[] = {
481 	{ .compatible = "ti,dac7512" },
482 	{ }
483 };
484 MODULE_DEVICE_TABLE(of, ad5446_of_ids);
485 
ad5446_spi_probe(struct spi_device * spi)486 static int ad5446_spi_probe(struct spi_device *spi)
487 {
488 	const struct spi_device_id *id = spi_get_device_id(spi);
489 
490 	return ad5446_probe(&spi->dev, id->name,
491 		&ad5446_spi_chip_info[id->driver_data]);
492 }
493 
ad5446_spi_remove(struct spi_device * spi)494 static void ad5446_spi_remove(struct spi_device *spi)
495 {
496 	ad5446_remove(&spi->dev);
497 }
498 
499 static struct spi_driver ad5446_spi_driver = {
500 	.driver = {
501 		.name	= "ad5446",
502 		.of_match_table = ad5446_of_ids,
503 	},
504 	.probe		= ad5446_spi_probe,
505 	.remove		= ad5446_spi_remove,
506 	.id_table	= ad5446_spi_ids,
507 };
508 
ad5446_spi_register_driver(void)509 static int __init ad5446_spi_register_driver(void)
510 {
511 	return spi_register_driver(&ad5446_spi_driver);
512 }
513 
ad5446_spi_unregister_driver(void)514 static void ad5446_spi_unregister_driver(void)
515 {
516 	spi_unregister_driver(&ad5446_spi_driver);
517 }
518 
519 #else
520 
ad5446_spi_register_driver(void)521 static inline int ad5446_spi_register_driver(void) { return 0; }
ad5446_spi_unregister_driver(void)522 static inline void ad5446_spi_unregister_driver(void) { }
523 
524 #endif
525 
526 #if IS_ENABLED(CONFIG_I2C)
527 
ad5622_write(struct ad5446_state * st,unsigned val)528 static int ad5622_write(struct ad5446_state *st, unsigned val)
529 {
530 	struct i2c_client *client = to_i2c_client(st->dev);
531 	__be16 data = cpu_to_be16(val);
532 	int ret;
533 
534 	ret = i2c_master_send(client, (char *)&data, sizeof(data));
535 	if (ret < 0)
536 		return ret;
537 	if (ret != sizeof(data))
538 		return -EIO;
539 
540 	return 0;
541 }
542 
543 /*
544  * ad5446_supported_i2c_device_ids:
545  * The AD5620/40/60 parts are available in different fixed internal reference
546  * voltage options. The actual part numbers may look differently
547  * (and a bit cryptic), however this style is used to make clear which
548  * parts are supported here.
549  */
550 enum ad5446_supported_i2c_device_ids {
551 	ID_AD5602,
552 	ID_AD5612,
553 	ID_AD5622,
554 };
555 
556 static const struct ad5446_chip_info ad5446_i2c_chip_info[] = {
557 	[ID_AD5602] = {
558 		.channel = AD5446_CHANNEL_POWERDOWN(8, 16, 4),
559 		.write = ad5622_write,
560 	},
561 	[ID_AD5612] = {
562 		.channel = AD5446_CHANNEL_POWERDOWN(10, 16, 2),
563 		.write = ad5622_write,
564 	},
565 	[ID_AD5622] = {
566 		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 0),
567 		.write = ad5622_write,
568 	},
569 };
570 
ad5446_i2c_probe(struct i2c_client * i2c)571 static int ad5446_i2c_probe(struct i2c_client *i2c)
572 {
573 	const struct i2c_device_id *id = i2c_client_get_device_id(i2c);
574 	return ad5446_probe(&i2c->dev, id->name,
575 		&ad5446_i2c_chip_info[id->driver_data]);
576 }
577 
ad5446_i2c_remove(struct i2c_client * i2c)578 static void ad5446_i2c_remove(struct i2c_client *i2c)
579 {
580 	ad5446_remove(&i2c->dev);
581 }
582 
583 static const struct i2c_device_id ad5446_i2c_ids[] = {
584 	{"ad5301", ID_AD5602},
585 	{"ad5311", ID_AD5612},
586 	{"ad5321", ID_AD5622},
587 	{"ad5602", ID_AD5602},
588 	{"ad5612", ID_AD5612},
589 	{"ad5622", ID_AD5622},
590 	{}
591 };
592 MODULE_DEVICE_TABLE(i2c, ad5446_i2c_ids);
593 
594 static struct i2c_driver ad5446_i2c_driver = {
595 	.driver = {
596 		   .name = "ad5446",
597 	},
598 	.probe_new = ad5446_i2c_probe,
599 	.remove = ad5446_i2c_remove,
600 	.id_table = ad5446_i2c_ids,
601 };
602 
ad5446_i2c_register_driver(void)603 static int __init ad5446_i2c_register_driver(void)
604 {
605 	return i2c_add_driver(&ad5446_i2c_driver);
606 }
607 
ad5446_i2c_unregister_driver(void)608 static void __exit ad5446_i2c_unregister_driver(void)
609 {
610 	i2c_del_driver(&ad5446_i2c_driver);
611 }
612 
613 #else
614 
ad5446_i2c_register_driver(void)615 static inline int ad5446_i2c_register_driver(void) { return 0; }
ad5446_i2c_unregister_driver(void)616 static inline void ad5446_i2c_unregister_driver(void) { }
617 
618 #endif
619 
ad5446_init(void)620 static int __init ad5446_init(void)
621 {
622 	int ret;
623 
624 	ret = ad5446_spi_register_driver();
625 	if (ret)
626 		return ret;
627 
628 	ret = ad5446_i2c_register_driver();
629 	if (ret) {
630 		ad5446_spi_unregister_driver();
631 		return ret;
632 	}
633 
634 	return 0;
635 }
636 module_init(ad5446_init);
637 
ad5446_exit(void)638 static void __exit ad5446_exit(void)
639 {
640 	ad5446_i2c_unregister_driver();
641 	ad5446_spi_unregister_driver();
642 }
643 module_exit(ad5446_exit);
644 
645 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
646 MODULE_DESCRIPTION("Analog Devices AD5444/AD5446 DAC");
647 MODULE_LICENSE("GPL v2");
648