xref: /linux/drivers/iio/dac/ad5064.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
1 /*
2  * AD5024, AD5025, AD5044, AD5045, AD5064, AD5064-1, AD5065, AD5628, AD5629R,
3  * AD5648, AD5666, AD5668, AD5669R 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/module.h>
13 #include <linux/kernel.h>
14 #include <linux/spi/spi.h>
15 #include <linux/i2c.h>
16 #include <linux/slab.h>
17 #include <linux/sysfs.h>
18 #include <linux/regulator/consumer.h>
19 #include <asm/unaligned.h>
20 
21 #include <linux/iio/iio.h>
22 #include <linux/iio/sysfs.h>
23 
24 #define AD5064_MAX_DAC_CHANNELS			8
25 #define AD5064_MAX_VREFS			4
26 
27 #define AD5064_ADDR(x)				((x) << 20)
28 #define AD5064_CMD(x)				((x) << 24)
29 
30 #define AD5064_ADDR_ALL_DAC			0xF
31 
32 #define AD5064_CMD_WRITE_INPUT_N		0x0
33 #define AD5064_CMD_UPDATE_DAC_N			0x1
34 #define AD5064_CMD_WRITE_INPUT_N_UPDATE_ALL	0x2
35 #define AD5064_CMD_WRITE_INPUT_N_UPDATE_N	0x3
36 #define AD5064_CMD_POWERDOWN_DAC		0x4
37 #define AD5064_CMD_CLEAR			0x5
38 #define AD5064_CMD_LDAC_MASK			0x6
39 #define AD5064_CMD_RESET			0x7
40 #define AD5064_CMD_CONFIG			0x8
41 
42 #define AD5064_CONFIG_DAISY_CHAIN_ENABLE	BIT(1)
43 #define AD5064_CONFIG_INT_VREF_ENABLE		BIT(0)
44 
45 #define AD5064_LDAC_PWRDN_NONE			0x0
46 #define AD5064_LDAC_PWRDN_1K			0x1
47 #define AD5064_LDAC_PWRDN_100K			0x2
48 #define AD5064_LDAC_PWRDN_3STATE		0x3
49 
50 /**
51  * struct ad5064_chip_info - chip specific information
52  * @shared_vref:	whether the vref supply is shared between channels
53  * @internal_vref:	internal reference voltage. 0 if the chip has no internal
54  *			vref.
55  * @channel:		channel specification
56  * @num_channels:	number of channels
57  */
58 
59 struct ad5064_chip_info {
60 	bool shared_vref;
61 	unsigned long internal_vref;
62 	const struct iio_chan_spec *channels;
63 	unsigned int num_channels;
64 };
65 
66 struct ad5064_state;
67 
68 typedef int (*ad5064_write_func)(struct ad5064_state *st, unsigned int cmd,
69 		unsigned int addr, unsigned int val);
70 
71 /**
72  * struct ad5064_state - driver instance specific data
73  * @dev:		the device for this driver instance
74  * @chip_info:		chip model specific constants, available modes etc
75  * @vref_reg:		vref supply regulators
76  * @pwr_down:		whether channel is powered down
77  * @pwr_down_mode:	channel's current power down mode
78  * @dac_cache:		current DAC raw value (chip does not support readback)
79  * @use_internal_vref:	set to true if the internal reference voltage should be
80  *			used.
81  * @write:		register write callback
82  * @data:		i2c/spi transfer buffers
83  */
84 
85 struct ad5064_state {
86 	struct device			*dev;
87 	const struct ad5064_chip_info	*chip_info;
88 	struct regulator_bulk_data	vref_reg[AD5064_MAX_VREFS];
89 	bool				pwr_down[AD5064_MAX_DAC_CHANNELS];
90 	u8				pwr_down_mode[AD5064_MAX_DAC_CHANNELS];
91 	unsigned int			dac_cache[AD5064_MAX_DAC_CHANNELS];
92 	bool				use_internal_vref;
93 
94 	ad5064_write_func		write;
95 
96 	/*
97 	 * DMA (thus cache coherency maintenance) requires the
98 	 * transfer buffers to live in their own cache lines.
99 	 */
100 	union {
101 		u8 i2c[3];
102 		__be32 spi;
103 	} data ____cacheline_aligned;
104 };
105 
106 enum ad5064_type {
107 	ID_AD5024,
108 	ID_AD5025,
109 	ID_AD5044,
110 	ID_AD5045,
111 	ID_AD5064,
112 	ID_AD5064_1,
113 	ID_AD5065,
114 	ID_AD5628_1,
115 	ID_AD5628_2,
116 	ID_AD5648_1,
117 	ID_AD5648_2,
118 	ID_AD5666_1,
119 	ID_AD5666_2,
120 	ID_AD5668_1,
121 	ID_AD5668_2,
122 };
123 
124 static int ad5064_write(struct ad5064_state *st, unsigned int cmd,
125 	unsigned int addr, unsigned int val, unsigned int shift)
126 {
127 	val <<= shift;
128 
129 	return st->write(st, cmd, addr, val);
130 }
131 
132 static int ad5064_sync_powerdown_mode(struct ad5064_state *st,
133 	const struct iio_chan_spec *chan)
134 {
135 	unsigned int val;
136 	int ret;
137 
138 	val = (0x1 << chan->address);
139 
140 	if (st->pwr_down[chan->channel])
141 		val |= st->pwr_down_mode[chan->channel] << 8;
142 
143 	ret = ad5064_write(st, AD5064_CMD_POWERDOWN_DAC, 0, val, 0);
144 
145 	return ret;
146 }
147 
148 static const char * const ad5064_powerdown_modes[] = {
149 	"1kohm_to_gnd",
150 	"100kohm_to_gnd",
151 	"three_state",
152 };
153 
154 static int ad5064_get_powerdown_mode(struct iio_dev *indio_dev,
155 	const struct iio_chan_spec *chan)
156 {
157 	struct ad5064_state *st = iio_priv(indio_dev);
158 
159 	return st->pwr_down_mode[chan->channel] - 1;
160 }
161 
162 static int ad5064_set_powerdown_mode(struct iio_dev *indio_dev,
163 	const struct iio_chan_spec *chan, unsigned int mode)
164 {
165 	struct ad5064_state *st = iio_priv(indio_dev);
166 	int ret;
167 
168 	mutex_lock(&indio_dev->mlock);
169 	st->pwr_down_mode[chan->channel] = mode + 1;
170 
171 	ret = ad5064_sync_powerdown_mode(st, chan);
172 	mutex_unlock(&indio_dev->mlock);
173 
174 	return ret;
175 }
176 
177 static const struct iio_enum ad5064_powerdown_mode_enum = {
178 	.items = ad5064_powerdown_modes,
179 	.num_items = ARRAY_SIZE(ad5064_powerdown_modes),
180 	.get = ad5064_get_powerdown_mode,
181 	.set = ad5064_set_powerdown_mode,
182 };
183 
184 static ssize_t ad5064_read_dac_powerdown(struct iio_dev *indio_dev,
185 	uintptr_t private, const struct iio_chan_spec *chan, char *buf)
186 {
187 	struct ad5064_state *st = iio_priv(indio_dev);
188 
189 	return sprintf(buf, "%d\n", st->pwr_down[chan->channel]);
190 }
191 
192 static ssize_t ad5064_write_dac_powerdown(struct iio_dev *indio_dev,
193 	 uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
194 	 size_t len)
195 {
196 	struct ad5064_state *st = iio_priv(indio_dev);
197 	bool pwr_down;
198 	int ret;
199 
200 	ret = strtobool(buf, &pwr_down);
201 	if (ret)
202 		return ret;
203 
204 	mutex_lock(&indio_dev->mlock);
205 	st->pwr_down[chan->channel] = pwr_down;
206 
207 	ret = ad5064_sync_powerdown_mode(st, chan);
208 	mutex_unlock(&indio_dev->mlock);
209 	return ret ? ret : len;
210 }
211 
212 static int ad5064_get_vref(struct ad5064_state *st,
213 	struct iio_chan_spec const *chan)
214 {
215 	unsigned int i;
216 
217 	if (st->use_internal_vref)
218 		return st->chip_info->internal_vref;
219 
220 	i = st->chip_info->shared_vref ? 0 : chan->channel;
221 	return regulator_get_voltage(st->vref_reg[i].consumer);
222 }
223 
224 static int ad5064_read_raw(struct iio_dev *indio_dev,
225 			   struct iio_chan_spec const *chan,
226 			   int *val,
227 			   int *val2,
228 			   long m)
229 {
230 	struct ad5064_state *st = iio_priv(indio_dev);
231 	int scale_uv;
232 
233 	switch (m) {
234 	case IIO_CHAN_INFO_RAW:
235 		*val = st->dac_cache[chan->channel];
236 		return IIO_VAL_INT;
237 	case IIO_CHAN_INFO_SCALE:
238 		scale_uv = ad5064_get_vref(st, chan);
239 		if (scale_uv < 0)
240 			return scale_uv;
241 
242 		*val = scale_uv / 1000;
243 		*val2 = chan->scan_type.realbits;
244 		return IIO_VAL_FRACTIONAL_LOG2;
245 	default:
246 		break;
247 	}
248 	return -EINVAL;
249 }
250 
251 static int ad5064_write_raw(struct iio_dev *indio_dev,
252 	struct iio_chan_spec const *chan, int val, int val2, long mask)
253 {
254 	struct ad5064_state *st = iio_priv(indio_dev);
255 	int ret;
256 
257 	switch (mask) {
258 	case IIO_CHAN_INFO_RAW:
259 		if (val >= (1 << chan->scan_type.realbits) || val < 0)
260 			return -EINVAL;
261 
262 		mutex_lock(&indio_dev->mlock);
263 		ret = ad5064_write(st, AD5064_CMD_WRITE_INPUT_N_UPDATE_N,
264 				chan->address, val, chan->scan_type.shift);
265 		if (ret == 0)
266 			st->dac_cache[chan->channel] = val;
267 		mutex_unlock(&indio_dev->mlock);
268 		break;
269 	default:
270 		ret = -EINVAL;
271 	}
272 
273 	return ret;
274 }
275 
276 static const struct iio_info ad5064_info = {
277 	.read_raw = ad5064_read_raw,
278 	.write_raw = ad5064_write_raw,
279 	.driver_module = THIS_MODULE,
280 };
281 
282 static const struct iio_chan_spec_ext_info ad5064_ext_info[] = {
283 	{
284 		.name = "powerdown",
285 		.read = ad5064_read_dac_powerdown,
286 		.write = ad5064_write_dac_powerdown,
287 		.shared = IIO_SEPARATE,
288 	},
289 	IIO_ENUM("powerdown_mode", IIO_SEPARATE, &ad5064_powerdown_mode_enum),
290 	IIO_ENUM_AVAILABLE("powerdown_mode", &ad5064_powerdown_mode_enum),
291 	{ },
292 };
293 
294 #define AD5064_CHANNEL(chan, addr, bits) {			\
295 	.type = IIO_VOLTAGE,					\
296 	.indexed = 1,						\
297 	.output = 1,						\
298 	.channel = (chan),					\
299 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
300 	BIT(IIO_CHAN_INFO_SCALE),					\
301 	.address = addr,					\
302 	.scan_type = IIO_ST('u', (bits), 16, 20 - (bits)),	\
303 	.ext_info = ad5064_ext_info,				\
304 }
305 
306 #define DECLARE_AD5064_CHANNELS(name, bits) \
307 const struct iio_chan_spec name[] = { \
308 	AD5064_CHANNEL(0, 0, bits), \
309 	AD5064_CHANNEL(1, 1, bits), \
310 	AD5064_CHANNEL(2, 2, bits), \
311 	AD5064_CHANNEL(3, 3, bits), \
312 	AD5064_CHANNEL(4, 4, bits), \
313 	AD5064_CHANNEL(5, 5, bits), \
314 	AD5064_CHANNEL(6, 6, bits), \
315 	AD5064_CHANNEL(7, 7, bits), \
316 }
317 
318 #define DECLARE_AD5065_CHANNELS(name, bits) \
319 const struct iio_chan_spec name[] = { \
320 	AD5064_CHANNEL(0, 0, bits), \
321 	AD5064_CHANNEL(1, 3, bits), \
322 }
323 
324 static DECLARE_AD5064_CHANNELS(ad5024_channels, 12);
325 static DECLARE_AD5064_CHANNELS(ad5044_channels, 14);
326 static DECLARE_AD5064_CHANNELS(ad5064_channels, 16);
327 
328 static DECLARE_AD5065_CHANNELS(ad5025_channels, 12);
329 static DECLARE_AD5065_CHANNELS(ad5045_channels, 14);
330 static DECLARE_AD5065_CHANNELS(ad5065_channels, 16);
331 
332 static const struct ad5064_chip_info ad5064_chip_info_tbl[] = {
333 	[ID_AD5024] = {
334 		.shared_vref = false,
335 		.channels = ad5024_channels,
336 		.num_channels = 4,
337 	},
338 	[ID_AD5025] = {
339 		.shared_vref = false,
340 		.channels = ad5025_channels,
341 		.num_channels = 2,
342 	},
343 	[ID_AD5044] = {
344 		.shared_vref = false,
345 		.channels = ad5044_channels,
346 		.num_channels = 4,
347 	},
348 	[ID_AD5045] = {
349 		.shared_vref = false,
350 		.channels = ad5045_channels,
351 		.num_channels = 2,
352 	},
353 	[ID_AD5064] = {
354 		.shared_vref = false,
355 		.channels = ad5064_channels,
356 		.num_channels = 4,
357 	},
358 	[ID_AD5064_1] = {
359 		.shared_vref = true,
360 		.channels = ad5064_channels,
361 		.num_channels = 4,
362 	},
363 	[ID_AD5065] = {
364 		.shared_vref = false,
365 		.channels = ad5065_channels,
366 		.num_channels = 2,
367 	},
368 	[ID_AD5628_1] = {
369 		.shared_vref = true,
370 		.internal_vref = 2500000,
371 		.channels = ad5024_channels,
372 		.num_channels = 8,
373 	},
374 	[ID_AD5628_2] = {
375 		.shared_vref = true,
376 		.internal_vref = 5000000,
377 		.channels = ad5024_channels,
378 		.num_channels = 8,
379 	},
380 	[ID_AD5648_1] = {
381 		.shared_vref = true,
382 		.internal_vref = 2500000,
383 		.channels = ad5044_channels,
384 		.num_channels = 8,
385 	},
386 	[ID_AD5648_2] = {
387 		.shared_vref = true,
388 		.internal_vref = 5000000,
389 		.channels = ad5044_channels,
390 		.num_channels = 8,
391 	},
392 	[ID_AD5666_1] = {
393 		.shared_vref = true,
394 		.internal_vref = 2500000,
395 		.channels = ad5064_channels,
396 		.num_channels = 4,
397 	},
398 	[ID_AD5666_2] = {
399 		.shared_vref = true,
400 		.internal_vref = 5000000,
401 		.channels = ad5064_channels,
402 		.num_channels = 4,
403 	},
404 	[ID_AD5668_1] = {
405 		.shared_vref = true,
406 		.internal_vref = 2500000,
407 		.channels = ad5064_channels,
408 		.num_channels = 8,
409 	},
410 	[ID_AD5668_2] = {
411 		.shared_vref = true,
412 		.internal_vref = 5000000,
413 		.channels = ad5064_channels,
414 		.num_channels = 8,
415 	},
416 };
417 
418 static inline unsigned int ad5064_num_vref(struct ad5064_state *st)
419 {
420 	return st->chip_info->shared_vref ? 1 : st->chip_info->num_channels;
421 }
422 
423 static const char * const ad5064_vref_names[] = {
424 	"vrefA",
425 	"vrefB",
426 	"vrefC",
427 	"vrefD",
428 };
429 
430 static const char * const ad5064_vref_name(struct ad5064_state *st,
431 	unsigned int vref)
432 {
433 	return st->chip_info->shared_vref ? "vref" : ad5064_vref_names[vref];
434 }
435 
436 static int ad5064_probe(struct device *dev, enum ad5064_type type,
437 			const char *name, ad5064_write_func write)
438 {
439 	struct iio_dev *indio_dev;
440 	struct ad5064_state *st;
441 	unsigned int midscale;
442 	unsigned int i;
443 	int ret;
444 
445 	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
446 	if (indio_dev == NULL)
447 		return  -ENOMEM;
448 
449 	st = iio_priv(indio_dev);
450 	dev_set_drvdata(dev, indio_dev);
451 
452 	st->chip_info = &ad5064_chip_info_tbl[type];
453 	st->dev = dev;
454 	st->write = write;
455 
456 	for (i = 0; i < ad5064_num_vref(st); ++i)
457 		st->vref_reg[i].supply = ad5064_vref_name(st, i);
458 
459 	ret = devm_regulator_bulk_get(dev, ad5064_num_vref(st),
460 		st->vref_reg);
461 	if (ret) {
462 		if (!st->chip_info->internal_vref)
463 			return ret;
464 		st->use_internal_vref = true;
465 		ret = ad5064_write(st, AD5064_CMD_CONFIG, 0,
466 			AD5064_CONFIG_INT_VREF_ENABLE, 0);
467 		if (ret) {
468 			dev_err(dev, "Failed to enable internal vref: %d\n",
469 				ret);
470 			return ret;
471 		}
472 	} else {
473 		ret = regulator_bulk_enable(ad5064_num_vref(st), st->vref_reg);
474 		if (ret)
475 			return ret;
476 	}
477 
478 	indio_dev->dev.parent = dev;
479 	indio_dev->name = name;
480 	indio_dev->info = &ad5064_info;
481 	indio_dev->modes = INDIO_DIRECT_MODE;
482 	indio_dev->channels = st->chip_info->channels;
483 	indio_dev->num_channels = st->chip_info->num_channels;
484 
485 	midscale = (1 << indio_dev->channels[0].scan_type.realbits) /  2;
486 
487 	for (i = 0; i < st->chip_info->num_channels; ++i) {
488 		st->pwr_down_mode[i] = AD5064_LDAC_PWRDN_1K;
489 		st->dac_cache[i] = midscale;
490 	}
491 
492 	ret = iio_device_register(indio_dev);
493 	if (ret)
494 		goto error_disable_reg;
495 
496 	return 0;
497 
498 error_disable_reg:
499 	if (!st->use_internal_vref)
500 		regulator_bulk_disable(ad5064_num_vref(st), st->vref_reg);
501 
502 	return ret;
503 }
504 
505 static int ad5064_remove(struct device *dev)
506 {
507 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
508 	struct ad5064_state *st = iio_priv(indio_dev);
509 
510 	iio_device_unregister(indio_dev);
511 
512 	if (!st->use_internal_vref)
513 		regulator_bulk_disable(ad5064_num_vref(st), st->vref_reg);
514 
515 	return 0;
516 }
517 
518 #if IS_ENABLED(CONFIG_SPI_MASTER)
519 
520 static int ad5064_spi_write(struct ad5064_state *st, unsigned int cmd,
521 	unsigned int addr, unsigned int val)
522 {
523 	struct spi_device *spi = to_spi_device(st->dev);
524 
525 	st->data.spi = cpu_to_be32(AD5064_CMD(cmd) | AD5064_ADDR(addr) | val);
526 	return spi_write(spi, &st->data.spi, sizeof(st->data.spi));
527 }
528 
529 static int ad5064_spi_probe(struct spi_device *spi)
530 {
531 	const struct spi_device_id *id = spi_get_device_id(spi);
532 
533 	return ad5064_probe(&spi->dev, id->driver_data, id->name,
534 				ad5064_spi_write);
535 }
536 
537 static int ad5064_spi_remove(struct spi_device *spi)
538 {
539 	return ad5064_remove(&spi->dev);
540 }
541 
542 static const struct spi_device_id ad5064_spi_ids[] = {
543 	{"ad5024", ID_AD5024},
544 	{"ad5025", ID_AD5025},
545 	{"ad5044", ID_AD5044},
546 	{"ad5045", ID_AD5045},
547 	{"ad5064", ID_AD5064},
548 	{"ad5064-1", ID_AD5064_1},
549 	{"ad5065", ID_AD5065},
550 	{"ad5628-1", ID_AD5628_1},
551 	{"ad5628-2", ID_AD5628_2},
552 	{"ad5648-1", ID_AD5648_1},
553 	{"ad5648-2", ID_AD5648_2},
554 	{"ad5666-1", ID_AD5666_1},
555 	{"ad5666-2", ID_AD5666_2},
556 	{"ad5668-1", ID_AD5668_1},
557 	{"ad5668-2", ID_AD5668_2},
558 	{"ad5668-3", ID_AD5668_2}, /* similar enough to ad5668-2 */
559 	{}
560 };
561 MODULE_DEVICE_TABLE(spi, ad5064_spi_ids);
562 
563 static struct spi_driver ad5064_spi_driver = {
564 	.driver = {
565 		   .name = "ad5064",
566 		   .owner = THIS_MODULE,
567 	},
568 	.probe = ad5064_spi_probe,
569 	.remove = ad5064_spi_remove,
570 	.id_table = ad5064_spi_ids,
571 };
572 
573 static int __init ad5064_spi_register_driver(void)
574 {
575 	return spi_register_driver(&ad5064_spi_driver);
576 }
577 
578 static void ad5064_spi_unregister_driver(void)
579 {
580 	spi_unregister_driver(&ad5064_spi_driver);
581 }
582 
583 #else
584 
585 static inline int ad5064_spi_register_driver(void) { return 0; }
586 static inline void ad5064_spi_unregister_driver(void) { }
587 
588 #endif
589 
590 #if IS_ENABLED(CONFIG_I2C)
591 
592 static int ad5064_i2c_write(struct ad5064_state *st, unsigned int cmd,
593 	unsigned int addr, unsigned int val)
594 {
595 	struct i2c_client *i2c = to_i2c_client(st->dev);
596 
597 	st->data.i2c[0] = (cmd << 4) | addr;
598 	put_unaligned_be16(val, &st->data.i2c[1]);
599 	return i2c_master_send(i2c, st->data.i2c, 3);
600 }
601 
602 static int ad5064_i2c_probe(struct i2c_client *i2c,
603 	const struct i2c_device_id *id)
604 {
605 	return ad5064_probe(&i2c->dev, id->driver_data, id->name,
606 						ad5064_i2c_write);
607 }
608 
609 static int ad5064_i2c_remove(struct i2c_client *i2c)
610 {
611 	return ad5064_remove(&i2c->dev);
612 }
613 
614 static const struct i2c_device_id ad5064_i2c_ids[] = {
615 	{"ad5629-1", ID_AD5628_1},
616 	{"ad5629-2", ID_AD5628_2},
617 	{"ad5629-3", ID_AD5628_2}, /* similar enough to ad5629-2 */
618 	{"ad5669-1", ID_AD5668_1},
619 	{"ad5669-2", ID_AD5668_2},
620 	{"ad5669-3", ID_AD5668_2}, /* similar enough to ad5669-2 */
621 	{}
622 };
623 MODULE_DEVICE_TABLE(i2c, ad5064_i2c_ids);
624 
625 static struct i2c_driver ad5064_i2c_driver = {
626 	.driver = {
627 		   .name = "ad5064",
628 		   .owner = THIS_MODULE,
629 	},
630 	.probe = ad5064_i2c_probe,
631 	.remove = ad5064_i2c_remove,
632 	.id_table = ad5064_i2c_ids,
633 };
634 
635 static int __init ad5064_i2c_register_driver(void)
636 {
637 	return i2c_add_driver(&ad5064_i2c_driver);
638 }
639 
640 static void __exit ad5064_i2c_unregister_driver(void)
641 {
642 	i2c_del_driver(&ad5064_i2c_driver);
643 }
644 
645 #else
646 
647 static inline int ad5064_i2c_register_driver(void) { return 0; }
648 static inline void ad5064_i2c_unregister_driver(void) { }
649 
650 #endif
651 
652 static int __init ad5064_init(void)
653 {
654 	int ret;
655 
656 	ret = ad5064_spi_register_driver();
657 	if (ret)
658 		return ret;
659 
660 	ret = ad5064_i2c_register_driver();
661 	if (ret) {
662 		ad5064_spi_unregister_driver();
663 		return ret;
664 	}
665 
666 	return 0;
667 }
668 module_init(ad5064_init);
669 
670 static void __exit ad5064_exit(void)
671 {
672 	ad5064_i2c_unregister_driver();
673 	ad5064_spi_unregister_driver();
674 }
675 module_exit(ad5064_exit);
676 
677 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
678 MODULE_DESCRIPTION("Analog Devices AD5024 and similar multi-channel DACs");
679 MODULE_LICENSE("GPL v2");
680