xref: /openbmc/linux/drivers/iio/frequency/adf4350.c (revision 8857df3a)
1 /*
2  * ADF4350/ADF4351 SPI Wideband Synthesizer driver
3  *
4  * Copyright 2012 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 
21 #include <linux/iio/iio.h>
22 #include <linux/iio/sysfs.h>
23 #include <linux/iio/frequency/adf4350.h>
24 
25 enum {
26 	ADF4350_FREQ,
27 	ADF4350_FREQ_REFIN,
28 	ADF4350_FREQ_RESOLUTION,
29 	ADF4350_PWRDOWN,
30 };
31 
32 struct adf4350_state {
33 	struct spi_device		*spi;
34 	struct regulator		*reg;
35 	struct adf4350_platform_data	*pdata;
36 	unsigned long			clkin;
37 	unsigned long			chspc; /* Channel Spacing */
38 	unsigned long			fpfd; /* Phase Frequency Detector */
39 	unsigned long			min_out_freq;
40 	unsigned			r0_fract;
41 	unsigned			r0_int;
42 	unsigned			r1_mod;
43 	unsigned			r4_rf_div_sel;
44 	unsigned long			regs[6];
45 	unsigned long			regs_hw[6];
46 
47 	/*
48 	 * DMA (thus cache coherency maintenance) requires the
49 	 * transfer buffers to live in their own cache lines.
50 	 */
51 	__be32				val ____cacheline_aligned;
52 };
53 
54 static struct adf4350_platform_data default_pdata = {
55 	.clkin = 122880000,
56 	.channel_spacing = 10000,
57 	.r2_user_settings = ADF4350_REG2_PD_POLARITY_POS |
58 			    ADF4350_REG2_CHARGE_PUMP_CURR_uA(2500),
59 	.r3_user_settings = ADF4350_REG3_12BIT_CLKDIV_MODE(0),
60 	.r4_user_settings = ADF4350_REG4_OUTPUT_PWR(3) |
61 			    ADF4350_REG4_MUTE_TILL_LOCK_EN,
62 	.gpio_lock_detect = -1,
63 };
64 
65 static int adf4350_sync_config(struct adf4350_state *st)
66 {
67 	int ret, i, doublebuf = 0;
68 
69 	for (i = ADF4350_REG5; i >= ADF4350_REG0; i--) {
70 		if ((st->regs_hw[i] != st->regs[i]) ||
71 			((i == ADF4350_REG0) && doublebuf)) {
72 
73 			switch (i) {
74 			case ADF4350_REG1:
75 			case ADF4350_REG4:
76 				doublebuf = 1;
77 				break;
78 			}
79 
80 			st->val  = cpu_to_be32(st->regs[i] | i);
81 			ret = spi_write(st->spi, &st->val, 4);
82 			if (ret < 0)
83 				return ret;
84 			st->regs_hw[i] = st->regs[i];
85 			dev_dbg(&st->spi->dev, "[%d] 0x%X\n",
86 				i, (u32)st->regs[i] | i);
87 		}
88 	}
89 	return 0;
90 }
91 
92 static int adf4350_reg_access(struct iio_dev *indio_dev,
93 			      unsigned reg, unsigned writeval,
94 			      unsigned *readval)
95 {
96 	struct adf4350_state *st = iio_priv(indio_dev);
97 	int ret;
98 
99 	if (reg > ADF4350_REG5)
100 		return -EINVAL;
101 
102 	mutex_lock(&indio_dev->mlock);
103 	if (readval == NULL) {
104 		st->regs[reg] = writeval & ~(BIT(0) | BIT(1) | BIT(2));
105 		ret = adf4350_sync_config(st);
106 	} else {
107 		*readval =  st->regs_hw[reg];
108 		ret = 0;
109 	}
110 	mutex_unlock(&indio_dev->mlock);
111 
112 	return ret;
113 }
114 
115 static int adf4350_tune_r_cnt(struct adf4350_state *st, unsigned short r_cnt)
116 {
117 	struct adf4350_platform_data *pdata = st->pdata;
118 
119 	do {
120 		r_cnt++;
121 		st->fpfd = (st->clkin * (pdata->ref_doubler_en ? 2 : 1)) /
122 			   (r_cnt * (pdata->ref_div2_en ? 2 : 1));
123 	} while (st->fpfd > ADF4350_MAX_FREQ_PFD);
124 
125 	return r_cnt;
126 }
127 
128 static int adf4350_set_freq(struct adf4350_state *st, unsigned long long freq)
129 {
130 	struct adf4350_platform_data *pdata = st->pdata;
131 	u64 tmp;
132 	u32 div_gcd, prescaler, chspc;
133 	u16 mdiv, r_cnt = 0;
134 	u8 band_sel_div;
135 
136 	if (freq > ADF4350_MAX_OUT_FREQ || freq < st->min_out_freq)
137 		return -EINVAL;
138 
139 	if (freq > ADF4350_MAX_FREQ_45_PRESC) {
140 		prescaler = ADF4350_REG1_PRESCALER;
141 		mdiv = 75;
142 	} else {
143 		prescaler = 0;
144 		mdiv = 23;
145 	}
146 
147 	st->r4_rf_div_sel = 0;
148 
149 	while (freq < ADF4350_MIN_VCO_FREQ) {
150 		freq <<= 1;
151 		st->r4_rf_div_sel++;
152 	}
153 
154 	/*
155 	 * Allow a predefined reference division factor
156 	 * if not set, compute our own
157 	 */
158 	if (pdata->ref_div_factor)
159 		r_cnt = pdata->ref_div_factor - 1;
160 
161 	chspc = st->chspc;
162 
163 	do  {
164 		do {
165 			do {
166 				r_cnt = adf4350_tune_r_cnt(st, r_cnt);
167 				st->r1_mod = st->fpfd / chspc;
168 				if (r_cnt > ADF4350_MAX_R_CNT) {
169 					/* try higher spacing values */
170 					chspc++;
171 					r_cnt = 0;
172 				}
173 			} while ((st->r1_mod > ADF4350_MAX_MODULUS) && r_cnt);
174 		} while (r_cnt == 0);
175 
176 		tmp = freq * (u64)st->r1_mod + (st->fpfd > 1);
177 		do_div(tmp, st->fpfd); /* Div round closest (n + d/2)/d */
178 		st->r0_fract = do_div(tmp, st->r1_mod);
179 		st->r0_int = tmp;
180 	} while (mdiv > st->r0_int);
181 
182 	band_sel_div = DIV_ROUND_UP(st->fpfd, ADF4350_MAX_BANDSEL_CLK);
183 
184 	if (st->r0_fract && st->r1_mod) {
185 		div_gcd = gcd(st->r1_mod, st->r0_fract);
186 		st->r1_mod /= div_gcd;
187 		st->r0_fract /= div_gcd;
188 	} else {
189 		st->r0_fract = 0;
190 		st->r1_mod = 1;
191 	}
192 
193 	dev_dbg(&st->spi->dev, "VCO: %llu Hz, PFD %lu Hz\n"
194 		"REF_DIV %d, R0_INT %d, R0_FRACT %d\n"
195 		"R1_MOD %d, RF_DIV %d\nPRESCALER %s, BAND_SEL_DIV %d\n",
196 		freq, st->fpfd, r_cnt, st->r0_int, st->r0_fract, st->r1_mod,
197 		1 << st->r4_rf_div_sel, prescaler ? "8/9" : "4/5",
198 		band_sel_div);
199 
200 	st->regs[ADF4350_REG0] = ADF4350_REG0_INT(st->r0_int) |
201 				 ADF4350_REG0_FRACT(st->r0_fract);
202 
203 	st->regs[ADF4350_REG1] = ADF4350_REG1_PHASE(1) |
204 				 ADF4350_REG1_MOD(st->r1_mod) |
205 				 prescaler;
206 
207 	st->regs[ADF4350_REG2] =
208 		ADF4350_REG2_10BIT_R_CNT(r_cnt) |
209 		ADF4350_REG2_DOUBLE_BUFF_EN |
210 		(pdata->ref_doubler_en ? ADF4350_REG2_RMULT2_EN : 0) |
211 		(pdata->ref_div2_en ? ADF4350_REG2_RDIV2_EN : 0) |
212 		(pdata->r2_user_settings & (ADF4350_REG2_PD_POLARITY_POS |
213 		ADF4350_REG2_LDP_6ns | ADF4350_REG2_LDF_INT_N |
214 		ADF4350_REG2_CHARGE_PUMP_CURR_uA(5000) |
215 		ADF4350_REG2_MUXOUT(0x7) | ADF4350_REG2_NOISE_MODE(0x9)));
216 
217 	st->regs[ADF4350_REG3] = pdata->r3_user_settings &
218 				 (ADF4350_REG3_12BIT_CLKDIV(0xFFF) |
219 				 ADF4350_REG3_12BIT_CLKDIV_MODE(0x3) |
220 				 ADF4350_REG3_12BIT_CSR_EN |
221 				 ADF4351_REG3_CHARGE_CANCELLATION_EN |
222 				 ADF4351_REG3_ANTI_BACKLASH_3ns_EN |
223 				 ADF4351_REG3_BAND_SEL_CLOCK_MODE_HIGH);
224 
225 	st->regs[ADF4350_REG4] =
226 		ADF4350_REG4_FEEDBACK_FUND |
227 		ADF4350_REG4_RF_DIV_SEL(st->r4_rf_div_sel) |
228 		ADF4350_REG4_8BIT_BAND_SEL_CLKDIV(band_sel_div) |
229 		ADF4350_REG4_RF_OUT_EN |
230 		(pdata->r4_user_settings &
231 		(ADF4350_REG4_OUTPUT_PWR(0x3) |
232 		ADF4350_REG4_AUX_OUTPUT_PWR(0x3) |
233 		ADF4350_REG4_AUX_OUTPUT_EN |
234 		ADF4350_REG4_AUX_OUTPUT_FUND |
235 		ADF4350_REG4_MUTE_TILL_LOCK_EN));
236 
237 	st->regs[ADF4350_REG5] = ADF4350_REG5_LD_PIN_MODE_DIGITAL;
238 
239 	return adf4350_sync_config(st);
240 }
241 
242 static ssize_t adf4350_write(struct iio_dev *indio_dev,
243 				    uintptr_t private,
244 				    const struct iio_chan_spec *chan,
245 				    const char *buf, size_t len)
246 {
247 	struct adf4350_state *st = iio_priv(indio_dev);
248 	unsigned long long readin;
249 	int ret;
250 
251 	ret = kstrtoull(buf, 10, &readin);
252 	if (ret)
253 		return ret;
254 
255 	mutex_lock(&indio_dev->mlock);
256 	switch ((u32)private) {
257 	case ADF4350_FREQ:
258 		ret = adf4350_set_freq(st, readin);
259 		break;
260 	case ADF4350_FREQ_REFIN:
261 		if (readin > ADF4350_MAX_FREQ_REFIN)
262 			ret = -EINVAL;
263 		else
264 			st->clkin = readin;
265 		break;
266 	case ADF4350_FREQ_RESOLUTION:
267 		if (readin == 0)
268 			ret = -EINVAL;
269 		else
270 			st->chspc = readin;
271 		break;
272 	case ADF4350_PWRDOWN:
273 		if (readin)
274 			st->regs[ADF4350_REG2] |= ADF4350_REG2_POWER_DOWN_EN;
275 		else
276 			st->regs[ADF4350_REG2] &= ~ADF4350_REG2_POWER_DOWN_EN;
277 
278 		adf4350_sync_config(st);
279 		break;
280 	default:
281 		ret = -EINVAL;
282 	}
283 	mutex_unlock(&indio_dev->mlock);
284 
285 	return ret ? ret : len;
286 }
287 
288 static ssize_t adf4350_read(struct iio_dev *indio_dev,
289 				   uintptr_t private,
290 				   const struct iio_chan_spec *chan,
291 				   char *buf)
292 {
293 	struct adf4350_state *st = iio_priv(indio_dev);
294 	unsigned long long val;
295 	int ret = 0;
296 
297 	mutex_lock(&indio_dev->mlock);
298 	switch ((u32)private) {
299 	case ADF4350_FREQ:
300 		val = (u64)((st->r0_int * st->r1_mod) + st->r0_fract) *
301 			(u64)st->fpfd;
302 		do_div(val, st->r1_mod * (1 << st->r4_rf_div_sel));
303 		/* PLL unlocked? return error */
304 		if (gpio_is_valid(st->pdata->gpio_lock_detect))
305 			if (!gpio_get_value(st->pdata->gpio_lock_detect)) {
306 				dev_dbg(&st->spi->dev, "PLL un-locked\n");
307 				ret = -EBUSY;
308 			}
309 		break;
310 	case ADF4350_FREQ_REFIN:
311 		val = st->clkin;
312 		break;
313 	case ADF4350_FREQ_RESOLUTION:
314 		val = st->chspc;
315 		break;
316 	case ADF4350_PWRDOWN:
317 		val = !!(st->regs[ADF4350_REG2] & ADF4350_REG2_POWER_DOWN_EN);
318 		break;
319 	default:
320 		ret = -EINVAL;
321 	}
322 	mutex_unlock(&indio_dev->mlock);
323 
324 	return ret < 0 ? ret : sprintf(buf, "%llu\n", val);
325 }
326 
327 #define _ADF4350_EXT_INFO(_name, _ident) { \
328 	.name = _name, \
329 	.read = adf4350_read, \
330 	.write = adf4350_write, \
331 	.private = _ident, \
332 }
333 
334 static const struct iio_chan_spec_ext_info adf4350_ext_info[] = {
335 	/* Ideally we use IIO_CHAN_INFO_FREQUENCY, but there are
336 	 * values > 2^32 in order to support the entire frequency range
337 	 * in Hz. Using scale is a bit ugly.
338 	 */
339 	_ADF4350_EXT_INFO("frequency", ADF4350_FREQ),
340 	_ADF4350_EXT_INFO("frequency_resolution", ADF4350_FREQ_RESOLUTION),
341 	_ADF4350_EXT_INFO("refin_frequency", ADF4350_FREQ_REFIN),
342 	_ADF4350_EXT_INFO("powerdown", ADF4350_PWRDOWN),
343 	{ },
344 };
345 
346 static const struct iio_chan_spec adf4350_chan = {
347 	.type = IIO_ALTVOLTAGE,
348 	.indexed = 1,
349 	.output = 1,
350 	.ext_info = adf4350_ext_info,
351 };
352 
353 static const struct iio_info adf4350_info = {
354 	.debugfs_reg_access = &adf4350_reg_access,
355 	.driver_module = THIS_MODULE,
356 };
357 
358 static int __devinit adf4350_probe(struct spi_device *spi)
359 {
360 	struct adf4350_platform_data *pdata = spi->dev.platform_data;
361 	struct iio_dev *indio_dev;
362 	struct adf4350_state *st;
363 	int ret;
364 
365 	if (!pdata) {
366 		dev_warn(&spi->dev, "no platform data? using default\n");
367 
368 		pdata = &default_pdata;
369 	}
370 
371 	indio_dev = iio_device_alloc(sizeof(*st));
372 	if (indio_dev == NULL)
373 		return -ENOMEM;
374 
375 	st = iio_priv(indio_dev);
376 
377 	st->reg = regulator_get(&spi->dev, "vcc");
378 	if (!IS_ERR(st->reg)) {
379 		ret = regulator_enable(st->reg);
380 		if (ret)
381 			goto error_put_reg;
382 	}
383 
384 	spi_set_drvdata(spi, indio_dev);
385 	st->spi = spi;
386 	st->pdata = pdata;
387 
388 	indio_dev->dev.parent = &spi->dev;
389 	indio_dev->name = (pdata->name[0] != 0) ? pdata->name :
390 		spi_get_device_id(spi)->name;
391 
392 	indio_dev->info = &adf4350_info;
393 	indio_dev->modes = INDIO_DIRECT_MODE;
394 	indio_dev->channels = &adf4350_chan;
395 	indio_dev->num_channels = 1;
396 
397 	st->chspc = pdata->channel_spacing;
398 	st->clkin = pdata->clkin;
399 
400 	st->min_out_freq = spi_get_device_id(spi)->driver_data == 4351 ?
401 		ADF4351_MIN_OUT_FREQ : ADF4350_MIN_OUT_FREQ;
402 
403 	memset(st->regs_hw, 0xFF, sizeof(st->regs_hw));
404 
405 	if (gpio_is_valid(pdata->gpio_lock_detect)) {
406 		ret = gpio_request(pdata->gpio_lock_detect, indio_dev->name);
407 		if (ret) {
408 			dev_err(&spi->dev, "fail to request lock detect GPIO-%d",
409 				pdata->gpio_lock_detect);
410 			goto error_disable_reg;
411 		}
412 		gpio_direction_input(pdata->gpio_lock_detect);
413 	}
414 
415 	if (pdata->power_up_frequency) {
416 		ret = adf4350_set_freq(st, pdata->power_up_frequency);
417 		if (ret)
418 			goto error_free_gpio;
419 	}
420 
421 	ret = iio_device_register(indio_dev);
422 	if (ret)
423 		goto error_free_gpio;
424 
425 	return 0;
426 
427 error_free_gpio:
428 	if (gpio_is_valid(pdata->gpio_lock_detect))
429 		gpio_free(pdata->gpio_lock_detect);
430 
431 error_disable_reg:
432 	if (!IS_ERR(st->reg))
433 		regulator_disable(st->reg);
434 error_put_reg:
435 	if (!IS_ERR(st->reg))
436 		regulator_put(st->reg);
437 
438 	iio_device_free(indio_dev);
439 
440 	return ret;
441 }
442 
443 static int __devexit adf4350_remove(struct spi_device *spi)
444 {
445 	struct iio_dev *indio_dev = spi_get_drvdata(spi);
446 	struct adf4350_state *st = iio_priv(indio_dev);
447 	struct regulator *reg = st->reg;
448 
449 	st->regs[ADF4350_REG2] |= ADF4350_REG2_POWER_DOWN_EN;
450 	adf4350_sync_config(st);
451 
452 	iio_device_unregister(indio_dev);
453 
454 	if (!IS_ERR(reg)) {
455 		regulator_disable(reg);
456 		regulator_put(reg);
457 	}
458 
459 	if (gpio_is_valid(st->pdata->gpio_lock_detect))
460 		gpio_free(st->pdata->gpio_lock_detect);
461 
462 	iio_device_free(indio_dev);
463 
464 	return 0;
465 }
466 
467 static const struct spi_device_id adf4350_id[] = {
468 	{"adf4350", 4350},
469 	{"adf4351", 4351},
470 	{}
471 };
472 
473 static struct spi_driver adf4350_driver = {
474 	.driver = {
475 		.name	= "adf4350",
476 		.owner	= THIS_MODULE,
477 	},
478 	.probe		= adf4350_probe,
479 	.remove		= __devexit_p(adf4350_remove),
480 	.id_table	= adf4350_id,
481 };
482 module_spi_driver(adf4350_driver);
483 
484 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
485 MODULE_DESCRIPTION("Analog Devices ADF4350/ADF4351 PLL");
486 MODULE_LICENSE("GPL v2");
487