xref: /linux/drivers/iio/frequency/adf4350.c (revision 2ba9268dd603d23e17643437b2246acb6844953b)
1 /*
2  * ADF4350/ADF4351 SPI Wideband Synthesizer driver
3  *
4  * Copyright 2012-2013 Analog Devices Inc.
5  *
6  * Licensed under the GPL-2.
7  */
8 
9 #include <linux/device.h>
10 #include <linux/kernel.h>
11 #include <linux/slab.h>
12 #include <linux/sysfs.h>
13 #include <linux/spi/spi.h>
14 #include <linux/regulator/consumer.h>
15 #include <linux/err.h>
16 #include <linux/module.h>
17 #include <linux/gcd.h>
18 #include <linux/gpio.h>
19 #include <asm/div64.h>
20 #include <linux/clk.h>
21 #include <linux/of.h>
22 #include <linux/of_gpio.h>
23 
24 #include <linux/iio/iio.h>
25 #include <linux/iio/sysfs.h>
26 #include <linux/iio/frequency/adf4350.h>
27 
28 enum {
29 	ADF4350_FREQ,
30 	ADF4350_FREQ_REFIN,
31 	ADF4350_FREQ_RESOLUTION,
32 	ADF4350_PWRDOWN,
33 };
34 
35 struct adf4350_state {
36 	struct spi_device		*spi;
37 	struct regulator		*reg;
38 	struct adf4350_platform_data	*pdata;
39 	struct clk			*clk;
40 	unsigned long			clkin;
41 	unsigned long			chspc; /* Channel Spacing */
42 	unsigned long			fpfd; /* Phase Frequency Detector */
43 	unsigned long			min_out_freq;
44 	unsigned			r0_fract;
45 	unsigned			r0_int;
46 	unsigned			r1_mod;
47 	unsigned			r4_rf_div_sel;
48 	unsigned long			regs[6];
49 	unsigned long			regs_hw[6];
50 	unsigned long long		freq_req;
51 	/*
52 	 * DMA (thus cache coherency maintenance) requires the
53 	 * transfer buffers to live in their own cache lines.
54 	 */
55 	__be32				val ____cacheline_aligned;
56 };
57 
58 static struct adf4350_platform_data default_pdata = {
59 	.channel_spacing = 10000,
60 	.r2_user_settings = ADF4350_REG2_PD_POLARITY_POS |
61 			    ADF4350_REG2_CHARGE_PUMP_CURR_uA(2500),
62 	.r3_user_settings = ADF4350_REG3_12BIT_CLKDIV_MODE(0),
63 	.r4_user_settings = ADF4350_REG4_OUTPUT_PWR(3) |
64 			    ADF4350_REG4_MUTE_TILL_LOCK_EN,
65 	.gpio_lock_detect = -1,
66 };
67 
68 static int adf4350_sync_config(struct adf4350_state *st)
69 {
70 	int ret, i, doublebuf = 0;
71 
72 	for (i = ADF4350_REG5; i >= ADF4350_REG0; i--) {
73 		if ((st->regs_hw[i] != st->regs[i]) ||
74 			((i == ADF4350_REG0) && doublebuf)) {
75 
76 			switch (i) {
77 			case ADF4350_REG1:
78 			case ADF4350_REG4:
79 				doublebuf = 1;
80 				break;
81 			}
82 
83 			st->val  = cpu_to_be32(st->regs[i] | i);
84 			ret = spi_write(st->spi, &st->val, 4);
85 			if (ret < 0)
86 				return ret;
87 			st->regs_hw[i] = st->regs[i];
88 			dev_dbg(&st->spi->dev, "[%d] 0x%X\n",
89 				i, (u32)st->regs[i] | i);
90 		}
91 	}
92 	return 0;
93 }
94 
95 static int adf4350_reg_access(struct iio_dev *indio_dev,
96 			      unsigned reg, unsigned writeval,
97 			      unsigned *readval)
98 {
99 	struct adf4350_state *st = iio_priv(indio_dev);
100 	int ret;
101 
102 	if (reg > ADF4350_REG5)
103 		return -EINVAL;
104 
105 	mutex_lock(&indio_dev->mlock);
106 	if (readval == NULL) {
107 		st->regs[reg] = writeval & ~(BIT(0) | BIT(1) | BIT(2));
108 		ret = adf4350_sync_config(st);
109 	} else {
110 		*readval =  st->regs_hw[reg];
111 		ret = 0;
112 	}
113 	mutex_unlock(&indio_dev->mlock);
114 
115 	return ret;
116 }
117 
118 static int adf4350_tune_r_cnt(struct adf4350_state *st, unsigned short r_cnt)
119 {
120 	struct adf4350_platform_data *pdata = st->pdata;
121 
122 	do {
123 		r_cnt++;
124 		st->fpfd = (st->clkin * (pdata->ref_doubler_en ? 2 : 1)) /
125 			   (r_cnt * (pdata->ref_div2_en ? 2 : 1));
126 	} while (st->fpfd > ADF4350_MAX_FREQ_PFD);
127 
128 	return r_cnt;
129 }
130 
131 static int adf4350_set_freq(struct adf4350_state *st, unsigned long long freq)
132 {
133 	struct adf4350_platform_data *pdata = st->pdata;
134 	u64 tmp;
135 	u32 div_gcd, prescaler, chspc;
136 	u16 mdiv, r_cnt = 0;
137 	u8 band_sel_div;
138 
139 	if (freq > ADF4350_MAX_OUT_FREQ || freq < st->min_out_freq)
140 		return -EINVAL;
141 
142 	if (freq > ADF4350_MAX_FREQ_45_PRESC) {
143 		prescaler = ADF4350_REG1_PRESCALER;
144 		mdiv = 75;
145 	} else {
146 		prescaler = 0;
147 		mdiv = 23;
148 	}
149 
150 	st->r4_rf_div_sel = 0;
151 
152 	while (freq < ADF4350_MIN_VCO_FREQ) {
153 		freq <<= 1;
154 		st->r4_rf_div_sel++;
155 	}
156 
157 	/*
158 	 * Allow a predefined reference division factor
159 	 * if not set, compute our own
160 	 */
161 	if (pdata->ref_div_factor)
162 		r_cnt = pdata->ref_div_factor - 1;
163 
164 	chspc = st->chspc;
165 
166 	do  {
167 		do {
168 			do {
169 				r_cnt = adf4350_tune_r_cnt(st, r_cnt);
170 				st->r1_mod = st->fpfd / chspc;
171 				if (r_cnt > ADF4350_MAX_R_CNT) {
172 					/* try higher spacing values */
173 					chspc++;
174 					r_cnt = 0;
175 				}
176 			} while ((st->r1_mod > ADF4350_MAX_MODULUS) && r_cnt);
177 		} while (r_cnt == 0);
178 
179 		tmp = freq * (u64)st->r1_mod + (st->fpfd >> 1);
180 		do_div(tmp, st->fpfd); /* Div round closest (n + d/2)/d */
181 		st->r0_fract = do_div(tmp, st->r1_mod);
182 		st->r0_int = tmp;
183 	} while (mdiv > st->r0_int);
184 
185 	band_sel_div = DIV_ROUND_UP(st->fpfd, ADF4350_MAX_BANDSEL_CLK);
186 
187 	if (st->r0_fract && st->r1_mod) {
188 		div_gcd = gcd(st->r1_mod, st->r0_fract);
189 		st->r1_mod /= div_gcd;
190 		st->r0_fract /= div_gcd;
191 	} else {
192 		st->r0_fract = 0;
193 		st->r1_mod = 1;
194 	}
195 
196 	dev_dbg(&st->spi->dev, "VCO: %llu Hz, PFD %lu Hz\n"
197 		"REF_DIV %d, R0_INT %d, R0_FRACT %d\n"
198 		"R1_MOD %d, RF_DIV %d\nPRESCALER %s, BAND_SEL_DIV %d\n",
199 		freq, st->fpfd, r_cnt, st->r0_int, st->r0_fract, st->r1_mod,
200 		1 << st->r4_rf_div_sel, prescaler ? "8/9" : "4/5",
201 		band_sel_div);
202 
203 	st->regs[ADF4350_REG0] = ADF4350_REG0_INT(st->r0_int) |
204 				 ADF4350_REG0_FRACT(st->r0_fract);
205 
206 	st->regs[ADF4350_REG1] = ADF4350_REG1_PHASE(1) |
207 				 ADF4350_REG1_MOD(st->r1_mod) |
208 				 prescaler;
209 
210 	st->regs[ADF4350_REG2] =
211 		ADF4350_REG2_10BIT_R_CNT(r_cnt) |
212 		ADF4350_REG2_DOUBLE_BUFF_EN |
213 		(pdata->ref_doubler_en ? ADF4350_REG2_RMULT2_EN : 0) |
214 		(pdata->ref_div2_en ? ADF4350_REG2_RDIV2_EN : 0) |
215 		(pdata->r2_user_settings & (ADF4350_REG2_PD_POLARITY_POS |
216 		ADF4350_REG2_LDP_6ns | ADF4350_REG2_LDF_INT_N |
217 		ADF4350_REG2_CHARGE_PUMP_CURR_uA(5000) |
218 		ADF4350_REG2_MUXOUT(0x7) | ADF4350_REG2_NOISE_MODE(0x3)));
219 
220 	st->regs[ADF4350_REG3] = pdata->r3_user_settings &
221 				 (ADF4350_REG3_12BIT_CLKDIV(0xFFF) |
222 				 ADF4350_REG3_12BIT_CLKDIV_MODE(0x3) |
223 				 ADF4350_REG3_12BIT_CSR_EN |
224 				 ADF4351_REG3_CHARGE_CANCELLATION_EN |
225 				 ADF4351_REG3_ANTI_BACKLASH_3ns_EN |
226 				 ADF4351_REG3_BAND_SEL_CLOCK_MODE_HIGH);
227 
228 	st->regs[ADF4350_REG4] =
229 		ADF4350_REG4_FEEDBACK_FUND |
230 		ADF4350_REG4_RF_DIV_SEL(st->r4_rf_div_sel) |
231 		ADF4350_REG4_8BIT_BAND_SEL_CLKDIV(band_sel_div) |
232 		ADF4350_REG4_RF_OUT_EN |
233 		(pdata->r4_user_settings &
234 		(ADF4350_REG4_OUTPUT_PWR(0x3) |
235 		ADF4350_REG4_AUX_OUTPUT_PWR(0x3) |
236 		ADF4350_REG4_AUX_OUTPUT_EN |
237 		ADF4350_REG4_AUX_OUTPUT_FUND |
238 		ADF4350_REG4_MUTE_TILL_LOCK_EN));
239 
240 	st->regs[ADF4350_REG5] = ADF4350_REG5_LD_PIN_MODE_DIGITAL;
241 	st->freq_req = freq;
242 
243 	return adf4350_sync_config(st);
244 }
245 
246 static ssize_t adf4350_write(struct iio_dev *indio_dev,
247 				    uintptr_t private,
248 				    const struct iio_chan_spec *chan,
249 				    const char *buf, size_t len)
250 {
251 	struct adf4350_state *st = iio_priv(indio_dev);
252 	unsigned long long readin;
253 	unsigned long tmp;
254 	int ret;
255 
256 	ret = kstrtoull(buf, 10, &readin);
257 	if (ret)
258 		return ret;
259 
260 	mutex_lock(&indio_dev->mlock);
261 	switch ((u32)private) {
262 	case ADF4350_FREQ:
263 		ret = adf4350_set_freq(st, readin);
264 		break;
265 	case ADF4350_FREQ_REFIN:
266 		if (readin > ADF4350_MAX_FREQ_REFIN) {
267 			ret = -EINVAL;
268 			break;
269 		}
270 
271 		if (st->clk) {
272 			tmp = clk_round_rate(st->clk, readin);
273 			if (tmp != readin) {
274 				ret = -EINVAL;
275 				break;
276 			}
277 			ret = clk_set_rate(st->clk, tmp);
278 			if (ret < 0)
279 				break;
280 		}
281 		st->clkin = readin;
282 		ret = adf4350_set_freq(st, st->freq_req);
283 		break;
284 	case ADF4350_FREQ_RESOLUTION:
285 		if (readin == 0)
286 			ret = -EINVAL;
287 		else
288 			st->chspc = readin;
289 		break;
290 	case ADF4350_PWRDOWN:
291 		if (readin)
292 			st->regs[ADF4350_REG2] |= ADF4350_REG2_POWER_DOWN_EN;
293 		else
294 			st->regs[ADF4350_REG2] &= ~ADF4350_REG2_POWER_DOWN_EN;
295 
296 		adf4350_sync_config(st);
297 		break;
298 	default:
299 		ret = -EINVAL;
300 	}
301 	mutex_unlock(&indio_dev->mlock);
302 
303 	return ret ? ret : len;
304 }
305 
306 static ssize_t adf4350_read(struct iio_dev *indio_dev,
307 				   uintptr_t private,
308 				   const struct iio_chan_spec *chan,
309 				   char *buf)
310 {
311 	struct adf4350_state *st = iio_priv(indio_dev);
312 	unsigned long long val;
313 	int ret = 0;
314 
315 	mutex_lock(&indio_dev->mlock);
316 	switch ((u32)private) {
317 	case ADF4350_FREQ:
318 		val = (u64)((st->r0_int * st->r1_mod) + st->r0_fract) *
319 			(u64)st->fpfd;
320 		do_div(val, st->r1_mod * (1 << st->r4_rf_div_sel));
321 		/* PLL unlocked? return error */
322 		if (gpio_is_valid(st->pdata->gpio_lock_detect))
323 			if (!gpio_get_value(st->pdata->gpio_lock_detect)) {
324 				dev_dbg(&st->spi->dev, "PLL un-locked\n");
325 				ret = -EBUSY;
326 			}
327 		break;
328 	case ADF4350_FREQ_REFIN:
329 		if (st->clk)
330 			st->clkin = clk_get_rate(st->clk);
331 
332 		val = st->clkin;
333 		break;
334 	case ADF4350_FREQ_RESOLUTION:
335 		val = st->chspc;
336 		break;
337 	case ADF4350_PWRDOWN:
338 		val = !!(st->regs[ADF4350_REG2] & ADF4350_REG2_POWER_DOWN_EN);
339 		break;
340 	default:
341 		ret = -EINVAL;
342 		val = 0;
343 	}
344 	mutex_unlock(&indio_dev->mlock);
345 
346 	return ret < 0 ? ret : sprintf(buf, "%llu\n", val);
347 }
348 
349 #define _ADF4350_EXT_INFO(_name, _ident) { \
350 	.name = _name, \
351 	.read = adf4350_read, \
352 	.write = adf4350_write, \
353 	.private = _ident, \
354 	.shared = IIO_SEPARATE, \
355 }
356 
357 static const struct iio_chan_spec_ext_info adf4350_ext_info[] = {
358 	/* Ideally we use IIO_CHAN_INFO_FREQUENCY, but there are
359 	 * values > 2^32 in order to support the entire frequency range
360 	 * in Hz. Using scale is a bit ugly.
361 	 */
362 	_ADF4350_EXT_INFO("frequency", ADF4350_FREQ),
363 	_ADF4350_EXT_INFO("frequency_resolution", ADF4350_FREQ_RESOLUTION),
364 	_ADF4350_EXT_INFO("refin_frequency", ADF4350_FREQ_REFIN),
365 	_ADF4350_EXT_INFO("powerdown", ADF4350_PWRDOWN),
366 	{ },
367 };
368 
369 static const struct iio_chan_spec adf4350_chan = {
370 	.type = IIO_ALTVOLTAGE,
371 	.indexed = 1,
372 	.output = 1,
373 	.ext_info = adf4350_ext_info,
374 };
375 
376 static const struct iio_info adf4350_info = {
377 	.debugfs_reg_access = &adf4350_reg_access,
378 	.driver_module = THIS_MODULE,
379 };
380 
381 #ifdef CONFIG_OF
382 static struct adf4350_platform_data *adf4350_parse_dt(struct device *dev)
383 {
384 	struct device_node *np = dev->of_node;
385 	struct adf4350_platform_data *pdata;
386 	unsigned int tmp;
387 	int ret;
388 
389 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
390 	if (!pdata)
391 		return NULL;
392 
393 	strncpy(&pdata->name[0], np->name, SPI_NAME_SIZE - 1);
394 
395 	tmp = 10000;
396 	of_property_read_u32(np, "adi,channel-spacing", &tmp);
397 	pdata->channel_spacing = tmp;
398 
399 	tmp = 0;
400 	of_property_read_u32(np, "adi,power-up-frequency", &tmp);
401 	pdata->power_up_frequency = tmp;
402 
403 	tmp = 0;
404 	of_property_read_u32(np, "adi,reference-div-factor", &tmp);
405 	pdata->ref_div_factor = tmp;
406 
407 	ret = of_get_gpio(np, 0);
408 	if (ret < 0)
409 		pdata->gpio_lock_detect = -1;
410 	else
411 		pdata->gpio_lock_detect = ret;
412 
413 	pdata->ref_doubler_en = of_property_read_bool(np,
414 			"adi,reference-doubler-enable");
415 	pdata->ref_div2_en = of_property_read_bool(np,
416 			"adi,reference-div2-enable");
417 
418 	/* r2_user_settings */
419 	pdata->r2_user_settings = of_property_read_bool(np,
420 			"adi,phase-detector-polarity-positive-enable") ?
421 			ADF4350_REG2_PD_POLARITY_POS : 0;
422 	pdata->r2_user_settings |= of_property_read_bool(np,
423 			"adi,lock-detect-precision-6ns-enable") ?
424 			ADF4350_REG2_LDP_6ns : 0;
425 	pdata->r2_user_settings |= of_property_read_bool(np,
426 			"adi,lock-detect-function-integer-n-enable") ?
427 			ADF4350_REG2_LDF_INT_N : 0;
428 
429 	tmp = 2500;
430 	of_property_read_u32(np, "adi,charge-pump-current", &tmp);
431 	pdata->r2_user_settings |= ADF4350_REG2_CHARGE_PUMP_CURR_uA(tmp);
432 
433 	tmp = 0;
434 	of_property_read_u32(np, "adi,muxout-select", &tmp);
435 	pdata->r2_user_settings |= ADF4350_REG2_MUXOUT(tmp);
436 
437 	pdata->r2_user_settings |= of_property_read_bool(np,
438 			"adi,low-spur-mode-enable") ?
439 			ADF4350_REG2_NOISE_MODE(0x3) : 0;
440 
441 	/* r3_user_settings */
442 
443 	pdata->r3_user_settings = of_property_read_bool(np,
444 			"adi,cycle-slip-reduction-enable") ?
445 			ADF4350_REG3_12BIT_CSR_EN : 0;
446 	pdata->r3_user_settings |= of_property_read_bool(np,
447 			"adi,charge-cancellation-enable") ?
448 			ADF4351_REG3_CHARGE_CANCELLATION_EN : 0;
449 
450 	pdata->r3_user_settings |= of_property_read_bool(np,
451 			"adi,anti-backlash-3ns-enable") ?
452 			ADF4351_REG3_ANTI_BACKLASH_3ns_EN : 0;
453 	pdata->r3_user_settings |= of_property_read_bool(np,
454 			"adi,band-select-clock-mode-high-enable") ?
455 			ADF4351_REG3_BAND_SEL_CLOCK_MODE_HIGH : 0;
456 
457 	tmp = 0;
458 	of_property_read_u32(np, "adi,12bit-clk-divider", &tmp);
459 	pdata->r3_user_settings |= ADF4350_REG3_12BIT_CLKDIV(tmp);
460 
461 	tmp = 0;
462 	of_property_read_u32(np, "adi,clk-divider-mode", &tmp);
463 	pdata->r3_user_settings |= ADF4350_REG3_12BIT_CLKDIV_MODE(tmp);
464 
465 	/* r4_user_settings */
466 
467 	pdata->r4_user_settings = of_property_read_bool(np,
468 			"adi,aux-output-enable") ?
469 			ADF4350_REG4_AUX_OUTPUT_EN : 0;
470 	pdata->r4_user_settings |= of_property_read_bool(np,
471 			"adi,aux-output-fundamental-enable") ?
472 			ADF4350_REG4_AUX_OUTPUT_FUND : 0;
473 	pdata->r4_user_settings |= of_property_read_bool(np,
474 			"adi,mute-till-lock-enable") ?
475 			ADF4350_REG4_MUTE_TILL_LOCK_EN : 0;
476 
477 	tmp = 0;
478 	of_property_read_u32(np, "adi,output-power", &tmp);
479 	pdata->r4_user_settings |= ADF4350_REG4_OUTPUT_PWR(tmp);
480 
481 	tmp = 0;
482 	of_property_read_u32(np, "adi,aux-output-power", &tmp);
483 	pdata->r4_user_settings |= ADF4350_REG4_AUX_OUTPUT_PWR(tmp);
484 
485 	return pdata;
486 }
487 #else
488 static
489 struct adf4350_platform_data *adf4350_parse_dt(struct device *dev)
490 {
491 	return NULL;
492 }
493 #endif
494 
495 static int adf4350_probe(struct spi_device *spi)
496 {
497 	struct adf4350_platform_data *pdata;
498 	struct iio_dev *indio_dev;
499 	struct adf4350_state *st;
500 	struct clk *clk = NULL;
501 	int ret;
502 
503 	if (spi->dev.of_node) {
504 		pdata = adf4350_parse_dt(&spi->dev);
505 		if (pdata == NULL)
506 			return -EINVAL;
507 	} else {
508 		pdata = spi->dev.platform_data;
509 	}
510 
511 	if (!pdata) {
512 		dev_warn(&spi->dev, "no platform data? using default\n");
513 		pdata = &default_pdata;
514 	}
515 
516 	if (!pdata->clkin) {
517 		clk = devm_clk_get(&spi->dev, "clkin");
518 		if (IS_ERR(clk))
519 			return -EPROBE_DEFER;
520 
521 		ret = clk_prepare_enable(clk);
522 		if (ret < 0)
523 			return ret;
524 	}
525 
526 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
527 	if (indio_dev == NULL) {
528 		ret =  -ENOMEM;
529 		goto error_disable_clk;
530 	}
531 
532 	st = iio_priv(indio_dev);
533 
534 	st->reg = devm_regulator_get(&spi->dev, "vcc");
535 	if (!IS_ERR(st->reg)) {
536 		ret = regulator_enable(st->reg);
537 		if (ret)
538 			goto error_disable_clk;
539 	}
540 
541 	spi_set_drvdata(spi, indio_dev);
542 	st->spi = spi;
543 	st->pdata = pdata;
544 
545 	indio_dev->dev.parent = &spi->dev;
546 	indio_dev->name = (pdata->name[0] != 0) ? pdata->name :
547 		spi_get_device_id(spi)->name;
548 
549 	indio_dev->info = &adf4350_info;
550 	indio_dev->modes = INDIO_DIRECT_MODE;
551 	indio_dev->channels = &adf4350_chan;
552 	indio_dev->num_channels = 1;
553 
554 	st->chspc = pdata->channel_spacing;
555 	if (clk) {
556 		st->clk = clk;
557 		st->clkin = clk_get_rate(clk);
558 	} else {
559 		st->clkin = pdata->clkin;
560 	}
561 
562 	st->min_out_freq = spi_get_device_id(spi)->driver_data == 4351 ?
563 		ADF4351_MIN_OUT_FREQ : ADF4350_MIN_OUT_FREQ;
564 
565 	memset(st->regs_hw, 0xFF, sizeof(st->regs_hw));
566 
567 	if (gpio_is_valid(pdata->gpio_lock_detect)) {
568 		ret = devm_gpio_request(&spi->dev, pdata->gpio_lock_detect,
569 					indio_dev->name);
570 		if (ret) {
571 			dev_err(&spi->dev, "fail to request lock detect GPIO-%d",
572 				pdata->gpio_lock_detect);
573 			goto error_disable_reg;
574 		}
575 		gpio_direction_input(pdata->gpio_lock_detect);
576 	}
577 
578 	if (pdata->power_up_frequency) {
579 		ret = adf4350_set_freq(st, pdata->power_up_frequency);
580 		if (ret)
581 			goto error_disable_reg;
582 	}
583 
584 	ret = iio_device_register(indio_dev);
585 	if (ret)
586 		goto error_disable_reg;
587 
588 	return 0;
589 
590 error_disable_reg:
591 	if (!IS_ERR(st->reg))
592 		regulator_disable(st->reg);
593 error_disable_clk:
594 	if (clk)
595 		clk_disable_unprepare(clk);
596 
597 	return ret;
598 }
599 
600 static int adf4350_remove(struct spi_device *spi)
601 {
602 	struct iio_dev *indio_dev = spi_get_drvdata(spi);
603 	struct adf4350_state *st = iio_priv(indio_dev);
604 	struct regulator *reg = st->reg;
605 
606 	st->regs[ADF4350_REG2] |= ADF4350_REG2_POWER_DOWN_EN;
607 	adf4350_sync_config(st);
608 
609 	iio_device_unregister(indio_dev);
610 
611 	if (st->clk)
612 		clk_disable_unprepare(st->clk);
613 
614 	if (!IS_ERR(reg))
615 		regulator_disable(reg);
616 
617 	return 0;
618 }
619 
620 static const struct spi_device_id adf4350_id[] = {
621 	{"adf4350", 4350},
622 	{"adf4351", 4351},
623 	{}
624 };
625 
626 static struct spi_driver adf4350_driver = {
627 	.driver = {
628 		.name	= "adf4350",
629 		.owner	= THIS_MODULE,
630 	},
631 	.probe		= adf4350_probe,
632 	.remove		= adf4350_remove,
633 	.id_table	= adf4350_id,
634 };
635 module_spi_driver(adf4350_driver);
636 
637 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
638 MODULE_DESCRIPTION("Analog Devices ADF4350/ADF4351 PLL");
639 MODULE_LICENSE("GPL v2");
640