xref: /openbmc/linux/drivers/iio/frequency/adf4350.c (revision 1a135d1a)
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;
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 	do  {
162 		r_cnt = adf4350_tune_r_cnt(st, r_cnt);
163 
164 		st->r1_mod = st->fpfd / st->chspc;
165 		while (st->r1_mod > ADF4350_MAX_MODULUS) {
166 			r_cnt = adf4350_tune_r_cnt(st, r_cnt);
167 			st->r1_mod = st->fpfd / st->chspc;
168 		}
169 
170 		tmp = freq * (u64)st->r1_mod + (st->fpfd > 1);
171 		do_div(tmp, st->fpfd); /* Div round closest (n + d/2)/d */
172 		st->r0_fract = do_div(tmp, st->r1_mod);
173 		st->r0_int = tmp;
174 	} while (mdiv > st->r0_int);
175 
176 	band_sel_div = DIV_ROUND_UP(st->fpfd, ADF4350_MAX_BANDSEL_CLK);
177 
178 	if (st->r0_fract && st->r1_mod) {
179 		div_gcd = gcd(st->r1_mod, st->r0_fract);
180 		st->r1_mod /= div_gcd;
181 		st->r0_fract /= div_gcd;
182 	} else {
183 		st->r0_fract = 0;
184 		st->r1_mod = 1;
185 	}
186 
187 	dev_dbg(&st->spi->dev, "VCO: %llu Hz, PFD %lu Hz\n"
188 		"REF_DIV %d, R0_INT %d, R0_FRACT %d\n"
189 		"R1_MOD %d, RF_DIV %d\nPRESCALER %s, BAND_SEL_DIV %d\n",
190 		freq, st->fpfd, r_cnt, st->r0_int, st->r0_fract, st->r1_mod,
191 		1 << st->r4_rf_div_sel, prescaler ? "8/9" : "4/5",
192 		band_sel_div);
193 
194 	st->regs[ADF4350_REG0] = ADF4350_REG0_INT(st->r0_int) |
195 				 ADF4350_REG0_FRACT(st->r0_fract);
196 
197 	st->regs[ADF4350_REG1] = ADF4350_REG1_PHASE(0) |
198 				 ADF4350_REG1_MOD(st->r1_mod) |
199 				 prescaler;
200 
201 	st->regs[ADF4350_REG2] =
202 		ADF4350_REG2_10BIT_R_CNT(r_cnt) |
203 		ADF4350_REG2_DOUBLE_BUFF_EN |
204 		(pdata->ref_doubler_en ? ADF4350_REG2_RMULT2_EN : 0) |
205 		(pdata->ref_div2_en ? ADF4350_REG2_RDIV2_EN : 0) |
206 		(pdata->r2_user_settings & (ADF4350_REG2_PD_POLARITY_POS |
207 		ADF4350_REG2_LDP_6ns | ADF4350_REG2_LDF_INT_N |
208 		ADF4350_REG2_CHARGE_PUMP_CURR_uA(5000) |
209 		ADF4350_REG2_MUXOUT(0x7) | ADF4350_REG2_NOISE_MODE(0x9)));
210 
211 	st->regs[ADF4350_REG3] = pdata->r3_user_settings &
212 				 (ADF4350_REG3_12BIT_CLKDIV(0xFFF) |
213 				 ADF4350_REG3_12BIT_CLKDIV_MODE(0x3) |
214 				 ADF4350_REG3_12BIT_CSR_EN |
215 				 ADF4351_REG3_CHARGE_CANCELLATION_EN |
216 				 ADF4351_REG3_ANTI_BACKLASH_3ns_EN |
217 				 ADF4351_REG3_BAND_SEL_CLOCK_MODE_HIGH);
218 
219 	st->regs[ADF4350_REG4] =
220 		ADF4350_REG4_FEEDBACK_FUND |
221 		ADF4350_REG4_RF_DIV_SEL(st->r4_rf_div_sel) |
222 		ADF4350_REG4_8BIT_BAND_SEL_CLKDIV(band_sel_div) |
223 		ADF4350_REG4_RF_OUT_EN |
224 		(pdata->r4_user_settings &
225 		(ADF4350_REG4_OUTPUT_PWR(0x3) |
226 		ADF4350_REG4_AUX_OUTPUT_PWR(0x3) |
227 		ADF4350_REG4_AUX_OUTPUT_EN |
228 		ADF4350_REG4_AUX_OUTPUT_FUND |
229 		ADF4350_REG4_MUTE_TILL_LOCK_EN));
230 
231 	st->regs[ADF4350_REG5] = ADF4350_REG5_LD_PIN_MODE_DIGITAL;
232 
233 	return adf4350_sync_config(st);
234 }
235 
236 static ssize_t adf4350_write(struct iio_dev *indio_dev,
237 				    uintptr_t private,
238 				    const struct iio_chan_spec *chan,
239 				    const char *buf, size_t len)
240 {
241 	struct adf4350_state *st = iio_priv(indio_dev);
242 	unsigned long long readin;
243 	int ret;
244 
245 	ret = kstrtoull(buf, 10, &readin);
246 	if (ret)
247 		return ret;
248 
249 	mutex_lock(&indio_dev->mlock);
250 	switch ((u32)private) {
251 	case ADF4350_FREQ:
252 		ret = adf4350_set_freq(st, readin);
253 		break;
254 	case ADF4350_FREQ_REFIN:
255 		if (readin > ADF4350_MAX_FREQ_REFIN)
256 			ret = -EINVAL;
257 		else
258 			st->clkin = readin;
259 		break;
260 	case ADF4350_FREQ_RESOLUTION:
261 		if (readin == 0)
262 			ret = -EINVAL;
263 		else
264 			st->chspc = readin;
265 		break;
266 	case ADF4350_PWRDOWN:
267 		if (readin)
268 			st->regs[ADF4350_REG2] |= ADF4350_REG2_POWER_DOWN_EN;
269 		else
270 			st->regs[ADF4350_REG2] &= ~ADF4350_REG2_POWER_DOWN_EN;
271 
272 		adf4350_sync_config(st);
273 		break;
274 	default:
275 		ret = -EINVAL;
276 	}
277 	mutex_unlock(&indio_dev->mlock);
278 
279 	return ret ? ret : len;
280 }
281 
282 static ssize_t adf4350_read(struct iio_dev *indio_dev,
283 				   uintptr_t private,
284 				   const struct iio_chan_spec *chan,
285 				   char *buf)
286 {
287 	struct adf4350_state *st = iio_priv(indio_dev);
288 	unsigned long long val;
289 	int ret = 0;
290 
291 	mutex_lock(&indio_dev->mlock);
292 	switch ((u32)private) {
293 	case ADF4350_FREQ:
294 		val = (u64)((st->r0_int * st->r1_mod) + st->r0_fract) *
295 			(u64)st->fpfd;
296 		do_div(val, st->r1_mod * (1 << st->r4_rf_div_sel));
297 		/* PLL unlocked? return error */
298 		if (gpio_is_valid(st->pdata->gpio_lock_detect))
299 			if (!gpio_get_value(st->pdata->gpio_lock_detect)) {
300 				dev_dbg(&st->spi->dev, "PLL un-locked\n");
301 				ret = -EBUSY;
302 			}
303 		break;
304 	case ADF4350_FREQ_REFIN:
305 		val = st->clkin;
306 		break;
307 	case ADF4350_FREQ_RESOLUTION:
308 		val = st->chspc;
309 		break;
310 	case ADF4350_PWRDOWN:
311 		val = !!(st->regs[ADF4350_REG2] & ADF4350_REG2_POWER_DOWN_EN);
312 		break;
313 	default:
314 		ret = -EINVAL;
315 	}
316 	mutex_unlock(&indio_dev->mlock);
317 
318 	return ret < 0 ? ret : sprintf(buf, "%llu\n", val);
319 }
320 
321 #define _ADF4350_EXT_INFO(_name, _ident) { \
322 	.name = _name, \
323 	.read = adf4350_read, \
324 	.write = adf4350_write, \
325 	.private = _ident, \
326 }
327 
328 static const struct iio_chan_spec_ext_info adf4350_ext_info[] = {
329 	/* Ideally we use IIO_CHAN_INFO_FREQUENCY, but there are
330 	 * values > 2^32 in order to support the entire frequency range
331 	 * in Hz. Using scale is a bit ugly.
332 	 */
333 	_ADF4350_EXT_INFO("frequency", ADF4350_FREQ),
334 	_ADF4350_EXT_INFO("frequency_resolution", ADF4350_FREQ_RESOLUTION),
335 	_ADF4350_EXT_INFO("refin_frequency", ADF4350_FREQ_REFIN),
336 	_ADF4350_EXT_INFO("powerdown", ADF4350_PWRDOWN),
337 	{ },
338 };
339 
340 static const struct iio_chan_spec adf4350_chan = {
341 	.type = IIO_ALTVOLTAGE,
342 	.indexed = 1,
343 	.output = 1,
344 	.ext_info = adf4350_ext_info,
345 };
346 
347 static const struct iio_info adf4350_info = {
348 	.debugfs_reg_access = &adf4350_reg_access,
349 	.driver_module = THIS_MODULE,
350 };
351 
352 static int __devinit adf4350_probe(struct spi_device *spi)
353 {
354 	struct adf4350_platform_data *pdata = spi->dev.platform_data;
355 	struct iio_dev *indio_dev;
356 	struct adf4350_state *st;
357 	int ret;
358 
359 	if (!pdata) {
360 		dev_warn(&spi->dev, "no platform data? using default\n");
361 
362 		pdata = &default_pdata;
363 	}
364 
365 	indio_dev = iio_device_alloc(sizeof(*st));
366 	if (indio_dev == NULL)
367 		return -ENOMEM;
368 
369 	st = iio_priv(indio_dev);
370 
371 	st->reg = regulator_get(&spi->dev, "vcc");
372 	if (!IS_ERR(st->reg)) {
373 		ret = regulator_enable(st->reg);
374 		if (ret)
375 			goto error_put_reg;
376 	}
377 
378 	spi_set_drvdata(spi, indio_dev);
379 	st->spi = spi;
380 	st->pdata = pdata;
381 
382 	indio_dev->dev.parent = &spi->dev;
383 	indio_dev->name = (pdata->name[0] != 0) ? pdata->name :
384 		spi_get_device_id(spi)->name;
385 
386 	indio_dev->info = &adf4350_info;
387 	indio_dev->modes = INDIO_DIRECT_MODE;
388 	indio_dev->channels = &adf4350_chan;
389 	indio_dev->num_channels = 1;
390 
391 	st->chspc = pdata->channel_spacing;
392 	st->clkin = pdata->clkin;
393 
394 	st->min_out_freq = spi_get_device_id(spi)->driver_data == 4351 ?
395 		ADF4351_MIN_OUT_FREQ : ADF4350_MIN_OUT_FREQ;
396 
397 	memset(st->regs_hw, 0xFF, sizeof(st->regs_hw));
398 
399 	if (gpio_is_valid(pdata->gpio_lock_detect)) {
400 		ret = gpio_request(pdata->gpio_lock_detect, indio_dev->name);
401 		if (ret) {
402 			dev_err(&spi->dev, "fail to request lock detect GPIO-%d",
403 				pdata->gpio_lock_detect);
404 			goto error_disable_reg;
405 		}
406 		gpio_direction_input(pdata->gpio_lock_detect);
407 	}
408 
409 	if (pdata->power_up_frequency) {
410 		ret = adf4350_set_freq(st, pdata->power_up_frequency);
411 		if (ret)
412 			goto error_free_gpio;
413 	}
414 
415 	ret = iio_device_register(indio_dev);
416 	if (ret)
417 		goto error_free_gpio;
418 
419 	return 0;
420 
421 error_free_gpio:
422 	if (gpio_is_valid(pdata->gpio_lock_detect))
423 		gpio_free(pdata->gpio_lock_detect);
424 
425 error_disable_reg:
426 	if (!IS_ERR(st->reg))
427 		regulator_disable(st->reg);
428 error_put_reg:
429 	if (!IS_ERR(st->reg))
430 		regulator_put(st->reg);
431 
432 	iio_device_free(indio_dev);
433 
434 	return ret;
435 }
436 
437 static int __devexit adf4350_remove(struct spi_device *spi)
438 {
439 	struct iio_dev *indio_dev = spi_get_drvdata(spi);
440 	struct adf4350_state *st = iio_priv(indio_dev);
441 	struct regulator *reg = st->reg;
442 
443 	st->regs[ADF4350_REG2] |= ADF4350_REG2_POWER_DOWN_EN;
444 	adf4350_sync_config(st);
445 
446 	iio_device_unregister(indio_dev);
447 
448 	if (!IS_ERR(reg)) {
449 		regulator_disable(reg);
450 		regulator_put(reg);
451 	}
452 
453 	if (gpio_is_valid(st->pdata->gpio_lock_detect))
454 		gpio_free(st->pdata->gpio_lock_detect);
455 
456 	iio_device_free(indio_dev);
457 
458 	return 0;
459 }
460 
461 static const struct spi_device_id adf4350_id[] = {
462 	{"adf4350", 4350},
463 	{"adf4351", 4351},
464 	{}
465 };
466 
467 static struct spi_driver adf4350_driver = {
468 	.driver = {
469 		.name	= "adf4350",
470 		.owner	= THIS_MODULE,
471 	},
472 	.probe		= adf4350_probe,
473 	.remove		= __devexit_p(adf4350_remove),
474 	.id_table	= adf4350_id,
475 };
476 module_spi_driver(adf4350_driver);
477 
478 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
479 MODULE_DESCRIPTION("Analog Devices ADF4350/ADF4351 PLL");
480 MODULE_LICENSE("GPL v2");
481