xref: /linux/drivers/iio/frequency/adf4350.c (revision b7019ac550eb3916f34d79db583e9b7ea2524afa)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * ADF4350/ADF4351 SPI Wideband Synthesizer driver
4  *
5  * Copyright 2012-2013 Analog Devices Inc.
6  */
7 
8 #include <linux/device.h>
9 #include <linux/kernel.h>
10 #include <linux/slab.h>
11 #include <linux/sysfs.h>
12 #include <linux/spi/spi.h>
13 #include <linux/regulator/consumer.h>
14 #include <linux/err.h>
15 #include <linux/module.h>
16 #include <linux/gcd.h>
17 #include <linux/gpio.h>
18 #include <asm/div64.h>
19 #include <linux/clk.h>
20 #include <linux/of.h>
21 #include <linux/of_gpio.h>
22 
23 #include <linux/iio/iio.h>
24 #include <linux/iio/sysfs.h>
25 #include <linux/iio/frequency/adf4350.h>
26 
27 enum {
28 	ADF4350_FREQ,
29 	ADF4350_FREQ_REFIN,
30 	ADF4350_FREQ_RESOLUTION,
31 	ADF4350_PWRDOWN,
32 };
33 
34 struct adf4350_state {
35 	struct spi_device		*spi;
36 	struct regulator		*reg;
37 	struct adf4350_platform_data	*pdata;
38 	struct clk			*clk;
39 	unsigned long			clkin;
40 	unsigned long			chspc; /* Channel Spacing */
41 	unsigned long			fpfd; /* Phase Frequency Detector */
42 	unsigned long			min_out_freq;
43 	unsigned			r0_fract;
44 	unsigned			r0_int;
45 	unsigned			r1_mod;
46 	unsigned			r4_rf_div_sel;
47 	unsigned long			regs[6];
48 	unsigned long			regs_hw[6];
49 	unsigned long long		freq_req;
50 	/*
51 	 * DMA (thus cache coherency maintenance) requires the
52 	 * transfer buffers to live in their own cache lines.
53 	 */
54 	__be32				val ____cacheline_aligned;
55 };
56 
57 static struct adf4350_platform_data default_pdata = {
58 	.channel_spacing = 10000,
59 	.r2_user_settings = ADF4350_REG2_PD_POLARITY_POS |
60 			    ADF4350_REG2_CHARGE_PUMP_CURR_uA(2500),
61 	.r3_user_settings = ADF4350_REG3_12BIT_CLKDIV_MODE(0),
62 	.r4_user_settings = ADF4350_REG4_OUTPUT_PWR(3) |
63 			    ADF4350_REG4_MUTE_TILL_LOCK_EN,
64 	.gpio_lock_detect = -1,
65 };
66 
67 static int adf4350_sync_config(struct adf4350_state *st)
68 {
69 	int ret, i, doublebuf = 0;
70 
71 	for (i = ADF4350_REG5; i >= ADF4350_REG0; i--) {
72 		if ((st->regs_hw[i] != st->regs[i]) ||
73 			((i == ADF4350_REG0) && doublebuf)) {
74 			switch (i) {
75 			case ADF4350_REG1:
76 			case ADF4350_REG4:
77 				doublebuf = 1;
78 				break;
79 			}
80 
81 			st->val  = cpu_to_be32(st->regs[i] | i);
82 			ret = spi_write(st->spi, &st->val, 4);
83 			if (ret < 0)
84 				return ret;
85 			st->regs_hw[i] = st->regs[i];
86 			dev_dbg(&st->spi->dev, "[%d] 0x%X\n",
87 				i, (u32)st->regs[i] | i);
88 		}
89 	}
90 	return 0;
91 }
92 
93 static int adf4350_reg_access(struct iio_dev *indio_dev,
94 			      unsigned reg, unsigned writeval,
95 			      unsigned *readval)
96 {
97 	struct adf4350_state *st = iio_priv(indio_dev);
98 	int ret;
99 
100 	if (reg > ADF4350_REG5)
101 		return -EINVAL;
102 
103 	mutex_lock(&indio_dev->mlock);
104 	if (readval == NULL) {
105 		st->regs[reg] = writeval & ~(BIT(0) | BIT(1) | BIT(2));
106 		ret = adf4350_sync_config(st);
107 	} else {
108 		*readval =  st->regs_hw[reg];
109 		ret = 0;
110 	}
111 	mutex_unlock(&indio_dev->mlock);
112 
113 	return ret;
114 }
115 
116 static int adf4350_tune_r_cnt(struct adf4350_state *st, unsigned short r_cnt)
117 {
118 	struct adf4350_platform_data *pdata = st->pdata;
119 
120 	do {
121 		r_cnt++;
122 		st->fpfd = (st->clkin * (pdata->ref_doubler_en ? 2 : 1)) /
123 			   (r_cnt * (pdata->ref_div2_en ? 2 : 1));
124 	} while (st->fpfd > ADF4350_MAX_FREQ_PFD);
125 
126 	return r_cnt;
127 }
128 
129 static int adf4350_set_freq(struct adf4350_state *st, unsigned long long freq)
130 {
131 	struct adf4350_platform_data *pdata = st->pdata;
132 	u64 tmp;
133 	u32 div_gcd, prescaler, chspc;
134 	u16 mdiv, r_cnt = 0;
135 	u8 band_sel_div;
136 
137 	if (freq > ADF4350_MAX_OUT_FREQ || freq < st->min_out_freq)
138 		return -EINVAL;
139 
140 	if (freq > ADF4350_MAX_FREQ_45_PRESC) {
141 		prescaler = ADF4350_REG1_PRESCALER;
142 		mdiv = 75;
143 	} else {
144 		prescaler = 0;
145 		mdiv = 23;
146 	}
147 
148 	st->r4_rf_div_sel = 0;
149 
150 	while (freq < ADF4350_MIN_VCO_FREQ) {
151 		freq <<= 1;
152 		st->r4_rf_div_sel++;
153 	}
154 
155 	/*
156 	 * Allow a predefined reference division factor
157 	 * if not set, compute our own
158 	 */
159 	if (pdata->ref_div_factor)
160 		r_cnt = pdata->ref_div_factor - 1;
161 
162 	chspc = st->chspc;
163 
164 	do  {
165 		do {
166 			do {
167 				r_cnt = adf4350_tune_r_cnt(st, r_cnt);
168 				st->r1_mod = st->fpfd / chspc;
169 				if (r_cnt > ADF4350_MAX_R_CNT) {
170 					/* try higher spacing values */
171 					chspc++;
172 					r_cnt = 0;
173 				}
174 			} while ((st->r1_mod > ADF4350_MAX_MODULUS) && r_cnt);
175 		} while (r_cnt == 0);
176 
177 		tmp = freq * (u64)st->r1_mod + (st->fpfd >> 1);
178 		do_div(tmp, st->fpfd); /* Div round closest (n + d/2)/d */
179 		st->r0_fract = do_div(tmp, st->r1_mod);
180 		st->r0_int = tmp;
181 	} while (mdiv > st->r0_int);
182 
183 	band_sel_div = DIV_ROUND_UP(st->fpfd, ADF4350_MAX_BANDSEL_CLK);
184 
185 	if (st->r0_fract && st->r1_mod) {
186 		div_gcd = gcd(st->r1_mod, st->r0_fract);
187 		st->r1_mod /= div_gcd;
188 		st->r0_fract /= div_gcd;
189 	} else {
190 		st->r0_fract = 0;
191 		st->r1_mod = 1;
192 	}
193 
194 	dev_dbg(&st->spi->dev, "VCO: %llu Hz, PFD %lu Hz\n"
195 		"REF_DIV %d, R0_INT %d, R0_FRACT %d\n"
196 		"R1_MOD %d, RF_DIV %d\nPRESCALER %s, BAND_SEL_DIV %d\n",
197 		freq, st->fpfd, r_cnt, st->r0_int, st->r0_fract, st->r1_mod,
198 		1 << st->r4_rf_div_sel, prescaler ? "8/9" : "4/5",
199 		band_sel_div);
200 
201 	st->regs[ADF4350_REG0] = ADF4350_REG0_INT(st->r0_int) |
202 				 ADF4350_REG0_FRACT(st->r0_fract);
203 
204 	st->regs[ADF4350_REG1] = ADF4350_REG1_PHASE(1) |
205 				 ADF4350_REG1_MOD(st->r1_mod) |
206 				 prescaler;
207 
208 	st->regs[ADF4350_REG2] =
209 		ADF4350_REG2_10BIT_R_CNT(r_cnt) |
210 		ADF4350_REG2_DOUBLE_BUFF_EN |
211 		(pdata->ref_doubler_en ? ADF4350_REG2_RMULT2_EN : 0) |
212 		(pdata->ref_div2_en ? ADF4350_REG2_RDIV2_EN : 0) |
213 		(pdata->r2_user_settings & (ADF4350_REG2_PD_POLARITY_POS |
214 		ADF4350_REG2_LDP_6ns | ADF4350_REG2_LDF_INT_N |
215 		ADF4350_REG2_CHARGE_PUMP_CURR_uA(5000) |
216 		ADF4350_REG2_MUXOUT(0x7) | ADF4350_REG2_NOISE_MODE(0x3)));
217 
218 	st->regs[ADF4350_REG3] = pdata->r3_user_settings &
219 				 (ADF4350_REG3_12BIT_CLKDIV(0xFFF) |
220 				 ADF4350_REG3_12BIT_CLKDIV_MODE(0x3) |
221 				 ADF4350_REG3_12BIT_CSR_EN |
222 				 ADF4351_REG3_CHARGE_CANCELLATION_EN |
223 				 ADF4351_REG3_ANTI_BACKLASH_3ns_EN |
224 				 ADF4351_REG3_BAND_SEL_CLOCK_MODE_HIGH);
225 
226 	st->regs[ADF4350_REG4] =
227 		ADF4350_REG4_FEEDBACK_FUND |
228 		ADF4350_REG4_RF_DIV_SEL(st->r4_rf_div_sel) |
229 		ADF4350_REG4_8BIT_BAND_SEL_CLKDIV(band_sel_div) |
230 		ADF4350_REG4_RF_OUT_EN |
231 		(pdata->r4_user_settings &
232 		(ADF4350_REG4_OUTPUT_PWR(0x3) |
233 		ADF4350_REG4_AUX_OUTPUT_PWR(0x3) |
234 		ADF4350_REG4_AUX_OUTPUT_EN |
235 		ADF4350_REG4_AUX_OUTPUT_FUND |
236 		ADF4350_REG4_MUTE_TILL_LOCK_EN));
237 
238 	st->regs[ADF4350_REG5] = ADF4350_REG5_LD_PIN_MODE_DIGITAL;
239 	st->freq_req = freq;
240 
241 	return adf4350_sync_config(st);
242 }
243 
244 static ssize_t adf4350_write(struct iio_dev *indio_dev,
245 				    uintptr_t private,
246 				    const struct iio_chan_spec *chan,
247 				    const char *buf, size_t len)
248 {
249 	struct adf4350_state *st = iio_priv(indio_dev);
250 	unsigned long long readin;
251 	unsigned long tmp;
252 	int ret;
253 
254 	ret = kstrtoull(buf, 10, &readin);
255 	if (ret)
256 		return ret;
257 
258 	mutex_lock(&indio_dev->mlock);
259 	switch ((u32)private) {
260 	case ADF4350_FREQ:
261 		ret = adf4350_set_freq(st, readin);
262 		break;
263 	case ADF4350_FREQ_REFIN:
264 		if (readin > ADF4350_MAX_FREQ_REFIN) {
265 			ret = -EINVAL;
266 			break;
267 		}
268 
269 		if (st->clk) {
270 			tmp = clk_round_rate(st->clk, readin);
271 			if (tmp != readin) {
272 				ret = -EINVAL;
273 				break;
274 			}
275 			ret = clk_set_rate(st->clk, tmp);
276 			if (ret < 0)
277 				break;
278 		}
279 		st->clkin = readin;
280 		ret = adf4350_set_freq(st, st->freq_req);
281 		break;
282 	case ADF4350_FREQ_RESOLUTION:
283 		if (readin == 0)
284 			ret = -EINVAL;
285 		else
286 			st->chspc = readin;
287 		break;
288 	case ADF4350_PWRDOWN:
289 		if (readin)
290 			st->regs[ADF4350_REG2] |= ADF4350_REG2_POWER_DOWN_EN;
291 		else
292 			st->regs[ADF4350_REG2] &= ~ADF4350_REG2_POWER_DOWN_EN;
293 
294 		adf4350_sync_config(st);
295 		break;
296 	default:
297 		ret = -EINVAL;
298 	}
299 	mutex_unlock(&indio_dev->mlock);
300 
301 	return ret ? ret : len;
302 }
303 
304 static ssize_t adf4350_read(struct iio_dev *indio_dev,
305 				   uintptr_t private,
306 				   const struct iio_chan_spec *chan,
307 				   char *buf)
308 {
309 	struct adf4350_state *st = iio_priv(indio_dev);
310 	unsigned long long val;
311 	int ret = 0;
312 
313 	mutex_lock(&indio_dev->mlock);
314 	switch ((u32)private) {
315 	case ADF4350_FREQ:
316 		val = (u64)((st->r0_int * st->r1_mod) + st->r0_fract) *
317 			(u64)st->fpfd;
318 		do_div(val, st->r1_mod * (1 << st->r4_rf_div_sel));
319 		/* PLL unlocked? return error */
320 		if (gpio_is_valid(st->pdata->gpio_lock_detect))
321 			if (!gpio_get_value(st->pdata->gpio_lock_detect)) {
322 				dev_dbg(&st->spi->dev, "PLL un-locked\n");
323 				ret = -EBUSY;
324 			}
325 		break;
326 	case ADF4350_FREQ_REFIN:
327 		if (st->clk)
328 			st->clkin = clk_get_rate(st->clk);
329 
330 		val = st->clkin;
331 		break;
332 	case ADF4350_FREQ_RESOLUTION:
333 		val = st->chspc;
334 		break;
335 	case ADF4350_PWRDOWN:
336 		val = !!(st->regs[ADF4350_REG2] & ADF4350_REG2_POWER_DOWN_EN);
337 		break;
338 	default:
339 		ret = -EINVAL;
340 		val = 0;
341 	}
342 	mutex_unlock(&indio_dev->mlock);
343 
344 	return ret < 0 ? ret : sprintf(buf, "%llu\n", val);
345 }
346 
347 #define _ADF4350_EXT_INFO(_name, _ident) { \
348 	.name = _name, \
349 	.read = adf4350_read, \
350 	.write = adf4350_write, \
351 	.private = _ident, \
352 	.shared = IIO_SEPARATE, \
353 }
354 
355 static const struct iio_chan_spec_ext_info adf4350_ext_info[] = {
356 	/* Ideally we use IIO_CHAN_INFO_FREQUENCY, but there are
357 	 * values > 2^32 in order to support the entire frequency range
358 	 * in Hz. Using scale is a bit ugly.
359 	 */
360 	_ADF4350_EXT_INFO("frequency", ADF4350_FREQ),
361 	_ADF4350_EXT_INFO("frequency_resolution", ADF4350_FREQ_RESOLUTION),
362 	_ADF4350_EXT_INFO("refin_frequency", ADF4350_FREQ_REFIN),
363 	_ADF4350_EXT_INFO("powerdown", ADF4350_PWRDOWN),
364 	{ },
365 };
366 
367 static const struct iio_chan_spec adf4350_chan = {
368 	.type = IIO_ALTVOLTAGE,
369 	.indexed = 1,
370 	.output = 1,
371 	.ext_info = adf4350_ext_info,
372 };
373 
374 static const struct iio_info adf4350_info = {
375 	.debugfs_reg_access = &adf4350_reg_access,
376 };
377 
378 #ifdef CONFIG_OF
379 static struct adf4350_platform_data *adf4350_parse_dt(struct device *dev)
380 {
381 	struct device_node *np = dev->of_node;
382 	struct adf4350_platform_data *pdata;
383 	unsigned int tmp;
384 	int ret;
385 
386 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
387 	if (!pdata)
388 		return NULL;
389 
390 	snprintf(&pdata->name[0], SPI_NAME_SIZE - 1, "%pOFn", np);
391 
392 	tmp = 10000;
393 	of_property_read_u32(np, "adi,channel-spacing", &tmp);
394 	pdata->channel_spacing = tmp;
395 
396 	tmp = 0;
397 	of_property_read_u32(np, "adi,power-up-frequency", &tmp);
398 	pdata->power_up_frequency = tmp;
399 
400 	tmp = 0;
401 	of_property_read_u32(np, "adi,reference-div-factor", &tmp);
402 	pdata->ref_div_factor = tmp;
403 
404 	ret = of_get_gpio(np, 0);
405 	if (ret < 0)
406 		pdata->gpio_lock_detect = -1;
407 	else
408 		pdata->gpio_lock_detect = ret;
409 
410 	pdata->ref_doubler_en = of_property_read_bool(np,
411 			"adi,reference-doubler-enable");
412 	pdata->ref_div2_en = of_property_read_bool(np,
413 			"adi,reference-div2-enable");
414 
415 	/* r2_user_settings */
416 	pdata->r2_user_settings = of_property_read_bool(np,
417 			"adi,phase-detector-polarity-positive-enable") ?
418 			ADF4350_REG2_PD_POLARITY_POS : 0;
419 	pdata->r2_user_settings |= of_property_read_bool(np,
420 			"adi,lock-detect-precision-6ns-enable") ?
421 			ADF4350_REG2_LDP_6ns : 0;
422 	pdata->r2_user_settings |= of_property_read_bool(np,
423 			"adi,lock-detect-function-integer-n-enable") ?
424 			ADF4350_REG2_LDF_INT_N : 0;
425 
426 	tmp = 2500;
427 	of_property_read_u32(np, "adi,charge-pump-current", &tmp);
428 	pdata->r2_user_settings |= ADF4350_REG2_CHARGE_PUMP_CURR_uA(tmp);
429 
430 	tmp = 0;
431 	of_property_read_u32(np, "adi,muxout-select", &tmp);
432 	pdata->r2_user_settings |= ADF4350_REG2_MUXOUT(tmp);
433 
434 	pdata->r2_user_settings |= of_property_read_bool(np,
435 			"adi,low-spur-mode-enable") ?
436 			ADF4350_REG2_NOISE_MODE(0x3) : 0;
437 
438 	/* r3_user_settings */
439 
440 	pdata->r3_user_settings = of_property_read_bool(np,
441 			"adi,cycle-slip-reduction-enable") ?
442 			ADF4350_REG3_12BIT_CSR_EN : 0;
443 	pdata->r3_user_settings |= of_property_read_bool(np,
444 			"adi,charge-cancellation-enable") ?
445 			ADF4351_REG3_CHARGE_CANCELLATION_EN : 0;
446 
447 	pdata->r3_user_settings |= of_property_read_bool(np,
448 			"adi,anti-backlash-3ns-enable") ?
449 			ADF4351_REG3_ANTI_BACKLASH_3ns_EN : 0;
450 	pdata->r3_user_settings |= of_property_read_bool(np,
451 			"adi,band-select-clock-mode-high-enable") ?
452 			ADF4351_REG3_BAND_SEL_CLOCK_MODE_HIGH : 0;
453 
454 	tmp = 0;
455 	of_property_read_u32(np, "adi,12bit-clk-divider", &tmp);
456 	pdata->r3_user_settings |= ADF4350_REG3_12BIT_CLKDIV(tmp);
457 
458 	tmp = 0;
459 	of_property_read_u32(np, "adi,clk-divider-mode", &tmp);
460 	pdata->r3_user_settings |= ADF4350_REG3_12BIT_CLKDIV_MODE(tmp);
461 
462 	/* r4_user_settings */
463 
464 	pdata->r4_user_settings = of_property_read_bool(np,
465 			"adi,aux-output-enable") ?
466 			ADF4350_REG4_AUX_OUTPUT_EN : 0;
467 	pdata->r4_user_settings |= of_property_read_bool(np,
468 			"adi,aux-output-fundamental-enable") ?
469 			ADF4350_REG4_AUX_OUTPUT_FUND : 0;
470 	pdata->r4_user_settings |= of_property_read_bool(np,
471 			"adi,mute-till-lock-enable") ?
472 			ADF4350_REG4_MUTE_TILL_LOCK_EN : 0;
473 
474 	tmp = 0;
475 	of_property_read_u32(np, "adi,output-power", &tmp);
476 	pdata->r4_user_settings |= ADF4350_REG4_OUTPUT_PWR(tmp);
477 
478 	tmp = 0;
479 	of_property_read_u32(np, "adi,aux-output-power", &tmp);
480 	pdata->r4_user_settings |= ADF4350_REG4_AUX_OUTPUT_PWR(tmp);
481 
482 	return pdata;
483 }
484 #else
485 static
486 struct adf4350_platform_data *adf4350_parse_dt(struct device *dev)
487 {
488 	return NULL;
489 }
490 #endif
491 
492 static int adf4350_probe(struct spi_device *spi)
493 {
494 	struct adf4350_platform_data *pdata;
495 	struct iio_dev *indio_dev;
496 	struct adf4350_state *st;
497 	struct clk *clk = NULL;
498 	int ret;
499 
500 	if (spi->dev.of_node) {
501 		pdata = adf4350_parse_dt(&spi->dev);
502 		if (pdata == NULL)
503 			return -EINVAL;
504 	} else {
505 		pdata = spi->dev.platform_data;
506 	}
507 
508 	if (!pdata) {
509 		dev_warn(&spi->dev, "no platform data? using default\n");
510 		pdata = &default_pdata;
511 	}
512 
513 	if (!pdata->clkin) {
514 		clk = devm_clk_get(&spi->dev, "clkin");
515 		if (IS_ERR(clk))
516 			return -EPROBE_DEFER;
517 
518 		ret = clk_prepare_enable(clk);
519 		if (ret < 0)
520 			return ret;
521 	}
522 
523 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
524 	if (indio_dev == NULL) {
525 		ret =  -ENOMEM;
526 		goto error_disable_clk;
527 	}
528 
529 	st = iio_priv(indio_dev);
530 
531 	st->reg = devm_regulator_get(&spi->dev, "vcc");
532 	if (!IS_ERR(st->reg)) {
533 		ret = regulator_enable(st->reg);
534 		if (ret)
535 			goto error_disable_clk;
536 	}
537 
538 	spi_set_drvdata(spi, indio_dev);
539 	st->spi = spi;
540 	st->pdata = pdata;
541 
542 	indio_dev->dev.parent = &spi->dev;
543 	indio_dev->name = (pdata->name[0] != 0) ? pdata->name :
544 		spi_get_device_id(spi)->name;
545 
546 	indio_dev->info = &adf4350_info;
547 	indio_dev->modes = INDIO_DIRECT_MODE;
548 	indio_dev->channels = &adf4350_chan;
549 	indio_dev->num_channels = 1;
550 
551 	st->chspc = pdata->channel_spacing;
552 	if (clk) {
553 		st->clk = clk;
554 		st->clkin = clk_get_rate(clk);
555 	} else {
556 		st->clkin = pdata->clkin;
557 	}
558 
559 	st->min_out_freq = spi_get_device_id(spi)->driver_data == 4351 ?
560 		ADF4351_MIN_OUT_FREQ : ADF4350_MIN_OUT_FREQ;
561 
562 	memset(st->regs_hw, 0xFF, sizeof(st->regs_hw));
563 
564 	if (gpio_is_valid(pdata->gpio_lock_detect)) {
565 		ret = devm_gpio_request(&spi->dev, pdata->gpio_lock_detect,
566 					indio_dev->name);
567 		if (ret) {
568 			dev_err(&spi->dev, "fail to request lock detect GPIO-%d",
569 				pdata->gpio_lock_detect);
570 			goto error_disable_reg;
571 		}
572 		gpio_direction_input(pdata->gpio_lock_detect);
573 	}
574 
575 	if (pdata->power_up_frequency) {
576 		ret = adf4350_set_freq(st, pdata->power_up_frequency);
577 		if (ret)
578 			goto error_disable_reg;
579 	}
580 
581 	ret = iio_device_register(indio_dev);
582 	if (ret)
583 		goto error_disable_reg;
584 
585 	return 0;
586 
587 error_disable_reg:
588 	if (!IS_ERR(st->reg))
589 		regulator_disable(st->reg);
590 error_disable_clk:
591 	if (clk)
592 		clk_disable_unprepare(clk);
593 
594 	return ret;
595 }
596 
597 static int adf4350_remove(struct spi_device *spi)
598 {
599 	struct iio_dev *indio_dev = spi_get_drvdata(spi);
600 	struct adf4350_state *st = iio_priv(indio_dev);
601 	struct regulator *reg = st->reg;
602 
603 	st->regs[ADF4350_REG2] |= ADF4350_REG2_POWER_DOWN_EN;
604 	adf4350_sync_config(st);
605 
606 	iio_device_unregister(indio_dev);
607 
608 	if (st->clk)
609 		clk_disable_unprepare(st->clk);
610 
611 	if (!IS_ERR(reg))
612 		regulator_disable(reg);
613 
614 	return 0;
615 }
616 
617 static const struct of_device_id adf4350_of_match[] = {
618 	{ .compatible = "adi,adf4350", },
619 	{ .compatible = "adi,adf4351", },
620 	{ /* sentinel */ },
621 };
622 MODULE_DEVICE_TABLE(of, adf4350_of_match);
623 
624 static const struct spi_device_id adf4350_id[] = {
625 	{"adf4350", 4350},
626 	{"adf4351", 4351},
627 	{}
628 };
629 MODULE_DEVICE_TABLE(spi, adf4350_id);
630 
631 static struct spi_driver adf4350_driver = {
632 	.driver = {
633 		.name	= "adf4350",
634 		.of_match_table = of_match_ptr(adf4350_of_match),
635 	},
636 	.probe		= adf4350_probe,
637 	.remove		= adf4350_remove,
638 	.id_table	= adf4350_id,
639 };
640 module_spi_driver(adf4350_driver);
641 
642 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
643 MODULE_DESCRIPTION("Analog Devices ADF4350/ADF4351 PLL");
644 MODULE_LICENSE("GPL v2");
645