1 /*
2  * AD5933 AD5934 Impedance Converter, Network Analyzer
3  *
4  * Copyright 2011 Analog Devices Inc.
5  *
6  * Licensed under the GPL-2.
7  */
8 
9 #include <linux/interrupt.h>
10 #include <linux/device.h>
11 #include <linux/kernel.h>
12 #include <linux/sysfs.h>
13 #include <linux/i2c.h>
14 #include <linux/regulator/consumer.h>
15 #include <linux/slab.h>
16 #include <linux/types.h>
17 #include <linux/err.h>
18 #include <linux/delay.h>
19 #include <linux/module.h>
20 #include <asm/div64.h>
21 
22 #include <linux/iio/iio.h>
23 #include <linux/iio/sysfs.h>
24 #include <linux/iio/buffer.h>
25 #include "../ring_sw.h"
26 
27 #include "ad5933.h"
28 
29 /* AD5933/AD5934 Registers */
30 #define AD5933_REG_CONTROL_HB		0x80	/* R/W, 2 bytes */
31 #define AD5933_REG_CONTROL_LB		0x81	/* R/W, 2 bytes */
32 #define AD5933_REG_FREQ_START		0x82	/* R/W, 3 bytes */
33 #define AD5933_REG_FREQ_INC		0x85	/* R/W, 3 bytes */
34 #define AD5933_REG_INC_NUM		0x88	/* R/W, 2 bytes, 9 bit */
35 #define AD5933_REG_SETTLING_CYCLES	0x8A	/* R/W, 2 bytes */
36 #define AD5933_REG_STATUS		0x8F	/* R, 1 byte */
37 #define AD5933_REG_TEMP_DATA		0x92	/* R, 2 bytes*/
38 #define AD5933_REG_REAL_DATA		0x94	/* R, 2 bytes*/
39 #define AD5933_REG_IMAG_DATA		0x96	/* R, 2 bytes*/
40 
41 /* AD5933_REG_CONTROL_HB Bits */
42 #define AD5933_CTRL_INIT_START_FREQ	(0x1 << 4)
43 #define AD5933_CTRL_START_SWEEP		(0x2 << 4)
44 #define AD5933_CTRL_INC_FREQ		(0x3 << 4)
45 #define AD5933_CTRL_REPEAT_FREQ		(0x4 << 4)
46 #define AD5933_CTRL_MEASURE_TEMP	(0x9 << 4)
47 #define AD5933_CTRL_POWER_DOWN		(0xA << 4)
48 #define AD5933_CTRL_STANDBY		(0xB << 4)
49 
50 #define AD5933_CTRL_RANGE_2000mVpp	(0x0 << 1)
51 #define AD5933_CTRL_RANGE_200mVpp	(0x1 << 1)
52 #define AD5933_CTRL_RANGE_400mVpp	(0x2 << 1)
53 #define AD5933_CTRL_RANGE_1000mVpp	(0x3 << 1)
54 #define AD5933_CTRL_RANGE(x)		((x) << 1)
55 
56 #define AD5933_CTRL_PGA_GAIN_1		(0x1 << 0)
57 #define AD5933_CTRL_PGA_GAIN_5		(0x0 << 0)
58 
59 /* AD5933_REG_CONTROL_LB Bits */
60 #define AD5933_CTRL_RESET		(0x1 << 4)
61 #define AD5933_CTRL_INT_SYSCLK		(0x0 << 3)
62 #define AD5933_CTRL_EXT_SYSCLK		(0x1 << 3)
63 
64 /* AD5933_REG_STATUS Bits */
65 #define AD5933_STAT_TEMP_VALID		(0x1 << 0)
66 #define AD5933_STAT_DATA_VALID		(0x1 << 1)
67 #define AD5933_STAT_SWEEP_DONE		(0x1 << 2)
68 
69 /* I2C Block Commands */
70 #define AD5933_I2C_BLOCK_WRITE		0xA0
71 #define AD5933_I2C_BLOCK_READ		0xA1
72 #define AD5933_I2C_ADDR_POINTER		0xB0
73 
74 /* Device Specs */
75 #define AD5933_INT_OSC_FREQ_Hz		16776000
76 #define AD5933_MAX_OUTPUT_FREQ_Hz	100000
77 #define AD5933_MAX_RETRIES		100
78 
79 #define AD5933_OUT_RANGE		1
80 #define AD5933_OUT_RANGE_AVAIL		2
81 #define AD5933_OUT_SETTLING_CYCLES	3
82 #define AD5933_IN_PGA_GAIN		4
83 #define AD5933_IN_PGA_GAIN_AVAIL	5
84 #define AD5933_FREQ_POINTS		6
85 
86 #define AD5933_POLL_TIME_ms		10
87 #define AD5933_INIT_EXCITATION_TIME_ms	100
88 
89 struct ad5933_state {
90 	struct i2c_client		*client;
91 	struct regulator		*reg;
92 	struct ad5933_platform_data	*pdata;
93 	struct delayed_work		work;
94 	unsigned long			mclk_hz;
95 	unsigned char			ctrl_hb;
96 	unsigned char			ctrl_lb;
97 	unsigned			range_avail[4];
98 	unsigned short			vref_mv;
99 	unsigned short			settling_cycles;
100 	unsigned short			freq_points;
101 	unsigned			freq_start;
102 	unsigned			freq_inc;
103 	unsigned			state;
104 	unsigned			poll_time_jiffies;
105 };
106 
107 static struct ad5933_platform_data ad5933_default_pdata  = {
108 	.vref_mv = 3300,
109 };
110 
111 static const struct iio_chan_spec ad5933_channels[] = {
112 	{
113 		.type = IIO_TEMP,
114 		.indexed = 1,
115 		.channel = 0,
116 		.info_mask = IIO_CHAN_INFO_PROCESSED_SEPARATE_BIT,
117 		.address = AD5933_REG_TEMP_DATA,
118 		.scan_type = {
119 			.sign = 's',
120 			.realbits = 14,
121 			.storagebits = 16,
122 		},
123 	}, { /* Ring Channels */
124 		.type = IIO_VOLTAGE,
125 		.indexed = 1,
126 		.channel = 0,
127 		.extend_name = "real_raw",
128 		.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT |
129 		IIO_CHAN_INFO_SCALE_SEPARATE_BIT,
130 		.address = AD5933_REG_REAL_DATA,
131 		.scan_index = 0,
132 		.scan_type = {
133 			.sign = 's',
134 			.realbits = 16,
135 			.storagebits = 16,
136 		},
137 	}, {
138 		.type = IIO_VOLTAGE,
139 		.indexed = 1,
140 		.channel = 0,
141 		.extend_name = "imag_raw",
142 		.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT |
143 		IIO_CHAN_INFO_SCALE_SEPARATE_BIT,
144 		.address = AD5933_REG_IMAG_DATA,
145 		.scan_index = 1,
146 		.scan_type = {
147 			.sign = 's',
148 			.realbits = 16,
149 			.storagebits = 16,
150 		},
151 	},
152 };
153 
154 static int ad5933_i2c_write(struct i2c_client *client,
155 			      u8 reg, u8 len, u8 *data)
156 {
157 	int ret;
158 
159 	while (len--) {
160 		ret = i2c_smbus_write_byte_data(client, reg++, *data++);
161 		if (ret < 0) {
162 			dev_err(&client->dev, "I2C write error\n");
163 			return ret;
164 		}
165 	}
166 	return 0;
167 }
168 
169 static int ad5933_i2c_read(struct i2c_client *client,
170 			      u8 reg, u8 len, u8 *data)
171 {
172 	int ret;
173 
174 	while (len--) {
175 		ret = i2c_smbus_read_byte_data(client, reg++);
176 		if (ret < 0) {
177 			dev_err(&client->dev, "I2C read error\n");
178 			return ret;
179 		}
180 		*data++ = ret;
181 	}
182 	return 0;
183 }
184 
185 static int ad5933_cmd(struct ad5933_state *st, unsigned char cmd)
186 {
187 	unsigned char dat = st->ctrl_hb | cmd;
188 
189 	return ad5933_i2c_write(st->client,
190 			AD5933_REG_CONTROL_HB, 1, &dat);
191 }
192 
193 static int ad5933_reset(struct ad5933_state *st)
194 {
195 	unsigned char dat = st->ctrl_lb | AD5933_CTRL_RESET;
196 	return ad5933_i2c_write(st->client,
197 			AD5933_REG_CONTROL_LB, 1, &dat);
198 }
199 
200 static int ad5933_wait_busy(struct ad5933_state *st, unsigned char event)
201 {
202 	unsigned char val, timeout = AD5933_MAX_RETRIES;
203 	int ret;
204 
205 	while (timeout--) {
206 		ret =  ad5933_i2c_read(st->client, AD5933_REG_STATUS, 1, &val);
207 		if (ret < 0)
208 			return ret;
209 		if (val & event)
210 			return val;
211 		cpu_relax();
212 		mdelay(1);
213 	}
214 
215 	return -EAGAIN;
216 }
217 
218 static int ad5933_set_freq(struct ad5933_state *st,
219 			   unsigned reg, unsigned long freq)
220 {
221 	unsigned long long freqreg;
222 	union {
223 		u32 d32;
224 		u8 d8[4];
225 	} dat;
226 
227 	freqreg = (u64) freq * (u64) (1 << 27);
228 	do_div(freqreg, st->mclk_hz / 4);
229 
230 	switch (reg) {
231 	case AD5933_REG_FREQ_START:
232 		st->freq_start = freq;
233 		break;
234 	case AD5933_REG_FREQ_INC:
235 		st->freq_inc = freq;
236 		break;
237 	default:
238 		return -EINVAL;
239 	}
240 
241 	dat.d32 = cpu_to_be32(freqreg);
242 	return ad5933_i2c_write(st->client, reg, 3, &dat.d8[1]);
243 }
244 
245 static int ad5933_setup(struct ad5933_state *st)
246 {
247 	unsigned short dat;
248 	int ret;
249 
250 	ret = ad5933_reset(st);
251 	if (ret < 0)
252 		return ret;
253 
254 	ret = ad5933_set_freq(st, AD5933_REG_FREQ_START, 10000);
255 	if (ret < 0)
256 		return ret;
257 
258 	ret = ad5933_set_freq(st, AD5933_REG_FREQ_INC, 200);
259 	if (ret < 0)
260 		return ret;
261 
262 	st->settling_cycles = 10;
263 	dat = cpu_to_be16(st->settling_cycles);
264 
265 	ret = ad5933_i2c_write(st->client,
266 			AD5933_REG_SETTLING_CYCLES, 2, (u8 *)&dat);
267 	if (ret < 0)
268 		return ret;
269 
270 	st->freq_points = 100;
271 	dat = cpu_to_be16(st->freq_points);
272 
273 	return ad5933_i2c_write(st->client, AD5933_REG_INC_NUM, 2, (u8 *)&dat);
274 }
275 
276 static void ad5933_calc_out_ranges(struct ad5933_state *st)
277 {
278 	int i;
279 	unsigned normalized_3v3[4] = {1980, 198, 383, 970};
280 
281 	for (i = 0; i < 4; i++)
282 		st->range_avail[i] = normalized_3v3[i] * st->vref_mv / 3300;
283 
284 }
285 
286 /*
287  * handles: AD5933_REG_FREQ_START and AD5933_REG_FREQ_INC
288  */
289 
290 static ssize_t ad5933_show_frequency(struct device *dev,
291 					struct device_attribute *attr,
292 					char *buf)
293 {
294 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
295 	struct ad5933_state *st = iio_priv(indio_dev);
296 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
297 	int ret;
298 	unsigned long long freqreg;
299 	union {
300 		u32 d32;
301 		u8 d8[4];
302 	} dat;
303 
304 	mutex_lock(&indio_dev->mlock);
305 	ret = ad5933_i2c_read(st->client, this_attr->address, 3, &dat.d8[1]);
306 	mutex_unlock(&indio_dev->mlock);
307 	if (ret < 0)
308 		return ret;
309 
310 	freqreg = be32_to_cpu(dat.d32) & 0xFFFFFF;
311 
312 	freqreg = (u64) freqreg * (u64) (st->mclk_hz / 4);
313 	do_div(freqreg, 1 << 27);
314 
315 	return sprintf(buf, "%d\n", (int) freqreg);
316 }
317 
318 static ssize_t ad5933_store_frequency(struct device *dev,
319 					 struct device_attribute *attr,
320 					 const char *buf,
321 					 size_t len)
322 {
323 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
324 	struct ad5933_state *st = iio_priv(indio_dev);
325 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
326 	long val;
327 	int ret;
328 
329 	ret = strict_strtoul(buf, 10, &val);
330 	if (ret)
331 		return ret;
332 
333 	if (val > AD5933_MAX_OUTPUT_FREQ_Hz)
334 		return -EINVAL;
335 
336 	mutex_lock(&indio_dev->mlock);
337 	ret = ad5933_set_freq(st, this_attr->address, val);
338 	mutex_unlock(&indio_dev->mlock);
339 
340 	return ret ? ret : len;
341 }
342 
343 static IIO_DEVICE_ATTR(out_voltage0_freq_start, S_IRUGO | S_IWUSR,
344 			ad5933_show_frequency,
345 			ad5933_store_frequency,
346 			AD5933_REG_FREQ_START);
347 
348 static IIO_DEVICE_ATTR(out_voltage0_freq_increment, S_IRUGO | S_IWUSR,
349 			ad5933_show_frequency,
350 			ad5933_store_frequency,
351 			AD5933_REG_FREQ_INC);
352 
353 static ssize_t ad5933_show(struct device *dev,
354 					struct device_attribute *attr,
355 					char *buf)
356 {
357 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
358 	struct ad5933_state *st = iio_priv(indio_dev);
359 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
360 	int ret = 0, len = 0;
361 
362 	mutex_lock(&indio_dev->mlock);
363 	switch ((u32) this_attr->address) {
364 	case AD5933_OUT_RANGE:
365 		len = sprintf(buf, "%d\n",
366 			      st->range_avail[(st->ctrl_hb >> 1) & 0x3]);
367 		break;
368 	case AD5933_OUT_RANGE_AVAIL:
369 		len = sprintf(buf, "%d %d %d %d\n", st->range_avail[0],
370 			      st->range_avail[3], st->range_avail[2],
371 			      st->range_avail[1]);
372 		break;
373 	case AD5933_OUT_SETTLING_CYCLES:
374 		len = sprintf(buf, "%d\n", st->settling_cycles);
375 		break;
376 	case AD5933_IN_PGA_GAIN:
377 		len = sprintf(buf, "%s\n",
378 			      (st->ctrl_hb & AD5933_CTRL_PGA_GAIN_1) ?
379 			      "1" : "0.2");
380 		break;
381 	case AD5933_IN_PGA_GAIN_AVAIL:
382 		len = sprintf(buf, "1 0.2\n");
383 		break;
384 	case AD5933_FREQ_POINTS:
385 		len = sprintf(buf, "%d\n", st->freq_points);
386 		break;
387 	default:
388 		ret = -EINVAL;
389 	}
390 
391 	mutex_unlock(&indio_dev->mlock);
392 	return ret ? ret : len;
393 }
394 
395 static ssize_t ad5933_store(struct device *dev,
396 					 struct device_attribute *attr,
397 					 const char *buf,
398 					 size_t len)
399 {
400 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
401 	struct ad5933_state *st = iio_priv(indio_dev);
402 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
403 	long val;
404 	int i, ret = 0;
405 	unsigned short dat;
406 
407 	if (this_attr->address != AD5933_IN_PGA_GAIN) {
408 		ret = strict_strtol(buf, 10, &val);
409 		if (ret)
410 			return ret;
411 	}
412 
413 	mutex_lock(&indio_dev->mlock);
414 	switch ((u32) this_attr->address) {
415 	case AD5933_OUT_RANGE:
416 		for (i = 0; i < 4; i++)
417 			if (val == st->range_avail[i]) {
418 				st->ctrl_hb &= ~AD5933_CTRL_RANGE(0x3);
419 				st->ctrl_hb |= AD5933_CTRL_RANGE(i);
420 				ret = ad5933_cmd(st, 0);
421 				break;
422 			}
423 		ret = -EINVAL;
424 		break;
425 	case AD5933_IN_PGA_GAIN:
426 		if (sysfs_streq(buf, "1")) {
427 			st->ctrl_hb |= AD5933_CTRL_PGA_GAIN_1;
428 		} else if (sysfs_streq(buf, "0.2")) {
429 			st->ctrl_hb &= ~AD5933_CTRL_PGA_GAIN_1;
430 		} else {
431 			ret = -EINVAL;
432 			break;
433 		}
434 		ret = ad5933_cmd(st, 0);
435 		break;
436 	case AD5933_OUT_SETTLING_CYCLES:
437 		val = clamp(val, 0L, 0x7FFL);
438 		st->settling_cycles = val;
439 
440 		/* 2x, 4x handling, see datasheet */
441 		if (val > 511)
442 			val = (val >> 1) | (1 << 9);
443 		else if (val > 1022)
444 			val = (val >> 2) | (3 << 9);
445 
446 		dat = cpu_to_be16(val);
447 		ret = ad5933_i2c_write(st->client,
448 				AD5933_REG_SETTLING_CYCLES, 2, (u8 *)&dat);
449 		break;
450 	case AD5933_FREQ_POINTS:
451 		val = clamp(val, 0L, 511L);
452 		st->freq_points = val;
453 
454 		dat = cpu_to_be16(val);
455 		ret = ad5933_i2c_write(st->client, AD5933_REG_INC_NUM, 2,
456 				       (u8 *)&dat);
457 		break;
458 	default:
459 		ret = -EINVAL;
460 	}
461 
462 	mutex_unlock(&indio_dev->mlock);
463 	return ret ? ret : len;
464 }
465 
466 static IIO_DEVICE_ATTR(out_voltage0_scale, S_IRUGO | S_IWUSR,
467 			ad5933_show,
468 			ad5933_store,
469 			AD5933_OUT_RANGE);
470 
471 static IIO_DEVICE_ATTR(out_voltage0_scale_available, S_IRUGO,
472 			ad5933_show,
473 			NULL,
474 			AD5933_OUT_RANGE_AVAIL);
475 
476 static IIO_DEVICE_ATTR(in_voltage0_scale, S_IRUGO | S_IWUSR,
477 			ad5933_show,
478 			ad5933_store,
479 			AD5933_IN_PGA_GAIN);
480 
481 static IIO_DEVICE_ATTR(in_voltage0_scale_available, S_IRUGO,
482 			ad5933_show,
483 			NULL,
484 			AD5933_IN_PGA_GAIN_AVAIL);
485 
486 static IIO_DEVICE_ATTR(out_voltage0_freq_points, S_IRUGO | S_IWUSR,
487 			ad5933_show,
488 			ad5933_store,
489 			AD5933_FREQ_POINTS);
490 
491 static IIO_DEVICE_ATTR(out_voltage0_settling_cycles, S_IRUGO | S_IWUSR,
492 			ad5933_show,
493 			ad5933_store,
494 			AD5933_OUT_SETTLING_CYCLES);
495 
496 /* note:
497  * ideally we would handle the scale attributes via the iio_info
498  * (read|write)_raw methods, however this part is a untypical since we
499  * don't create dedicated sysfs channel attributes for out0 and in0.
500  */
501 static struct attribute *ad5933_attributes[] = {
502 	&iio_dev_attr_out_voltage0_scale.dev_attr.attr,
503 	&iio_dev_attr_out_voltage0_scale_available.dev_attr.attr,
504 	&iio_dev_attr_out_voltage0_freq_start.dev_attr.attr,
505 	&iio_dev_attr_out_voltage0_freq_increment.dev_attr.attr,
506 	&iio_dev_attr_out_voltage0_freq_points.dev_attr.attr,
507 	&iio_dev_attr_out_voltage0_settling_cycles.dev_attr.attr,
508 	&iio_dev_attr_in_voltage0_scale.dev_attr.attr,
509 	&iio_dev_attr_in_voltage0_scale_available.dev_attr.attr,
510 	NULL
511 };
512 
513 static const struct attribute_group ad5933_attribute_group = {
514 	.attrs = ad5933_attributes,
515 };
516 
517 static int ad5933_read_raw(struct iio_dev *indio_dev,
518 			   struct iio_chan_spec const *chan,
519 			   int *val,
520 			   int *val2,
521 			   long m)
522 {
523 	struct ad5933_state *st = iio_priv(indio_dev);
524 	unsigned short dat;
525 	int ret = -EINVAL;
526 
527 	mutex_lock(&indio_dev->mlock);
528 	switch (m) {
529 	case IIO_CHAN_INFO_RAW:
530 	case IIO_CHAN_INFO_PROCESSED:
531 		if (iio_buffer_enabled(indio_dev)) {
532 			ret = -EBUSY;
533 			goto out;
534 		}
535 		ret = ad5933_cmd(st, AD5933_CTRL_MEASURE_TEMP);
536 		if (ret < 0)
537 			goto out;
538 		ret = ad5933_wait_busy(st, AD5933_STAT_TEMP_VALID);
539 		if (ret < 0)
540 			goto out;
541 
542 		ret = ad5933_i2c_read(st->client,
543 				AD5933_REG_TEMP_DATA, 2,
544 				(u8 *)&dat);
545 		if (ret < 0)
546 			goto out;
547 		mutex_unlock(&indio_dev->mlock);
548 		ret = be16_to_cpu(dat);
549 		/* Temp in Milli degrees Celsius */
550 		if (ret < 8192)
551 			*val = ret * 1000 / 32;
552 		else
553 			*val = (ret - 16384) * 1000 / 32;
554 
555 		return IIO_VAL_INT;
556 	}
557 
558 out:
559 	mutex_unlock(&indio_dev->mlock);
560 	return ret;
561 }
562 
563 static const struct iio_info ad5933_info = {
564 	.read_raw = &ad5933_read_raw,
565 	.attrs = &ad5933_attribute_group,
566 	.driver_module = THIS_MODULE,
567 };
568 
569 static int ad5933_ring_preenable(struct iio_dev *indio_dev)
570 {
571 	struct ad5933_state *st = iio_priv(indio_dev);
572 	int ret;
573 
574 	if (bitmap_empty(indio_dev->active_scan_mask, indio_dev->masklength))
575 		return -EINVAL;
576 
577 	ret = iio_sw_buffer_preenable(indio_dev);
578 	if (ret < 0)
579 		return ret;
580 
581 	ret = ad5933_reset(st);
582 	if (ret < 0)
583 		return ret;
584 
585 	ret = ad5933_cmd(st, AD5933_CTRL_STANDBY);
586 	if (ret < 0)
587 		return ret;
588 
589 	ret = ad5933_cmd(st, AD5933_CTRL_INIT_START_FREQ);
590 	if (ret < 0)
591 		return ret;
592 
593 	st->state = AD5933_CTRL_INIT_START_FREQ;
594 
595 	return 0;
596 }
597 
598 static int ad5933_ring_postenable(struct iio_dev *indio_dev)
599 {
600 	struct ad5933_state *st = iio_priv(indio_dev);
601 
602 	/* AD5933_CTRL_INIT_START_FREQ:
603 	 * High Q complex circuits require a long time to reach steady state.
604 	 * To facilitate the measurement of such impedances, this mode allows
605 	 * the user full control of the settling time requirement before
606 	 * entering start frequency sweep mode where the impedance measurement
607 	 * takes place. In this mode the impedance is excited with the
608 	 * programmed start frequency (ad5933_ring_preenable),
609 	 * but no measurement takes place.
610 	 */
611 
612 	schedule_delayed_work(&st->work,
613 			      msecs_to_jiffies(AD5933_INIT_EXCITATION_TIME_ms));
614 	return 0;
615 }
616 
617 static int ad5933_ring_postdisable(struct iio_dev *indio_dev)
618 {
619 	struct ad5933_state *st = iio_priv(indio_dev);
620 
621 	cancel_delayed_work_sync(&st->work);
622 	return ad5933_cmd(st, AD5933_CTRL_POWER_DOWN);
623 }
624 
625 static const struct iio_buffer_setup_ops ad5933_ring_setup_ops = {
626 	.preenable = &ad5933_ring_preenable,
627 	.postenable = &ad5933_ring_postenable,
628 	.postdisable = &ad5933_ring_postdisable,
629 };
630 
631 static int ad5933_register_ring_funcs_and_init(struct iio_dev *indio_dev)
632 {
633 	indio_dev->buffer = iio_sw_rb_allocate(indio_dev);
634 	if (!indio_dev->buffer)
635 		return -ENOMEM;
636 
637 	/* Ring buffer functions - here trigger setup related */
638 	indio_dev->setup_ops = &ad5933_ring_setup_ops;
639 
640 	indio_dev->modes |= INDIO_BUFFER_HARDWARE;
641 
642 	return 0;
643 }
644 
645 static void ad5933_work(struct work_struct *work)
646 {
647 	struct ad5933_state *st = container_of(work,
648 		struct ad5933_state, work.work);
649 	struct iio_dev *indio_dev = i2c_get_clientdata(st->client);
650 	signed short buf[2];
651 	unsigned char status;
652 
653 	mutex_lock(&indio_dev->mlock);
654 	if (st->state == AD5933_CTRL_INIT_START_FREQ) {
655 		/* start sweep */
656 		ad5933_cmd(st, AD5933_CTRL_START_SWEEP);
657 		st->state = AD5933_CTRL_START_SWEEP;
658 		schedule_delayed_work(&st->work, st->poll_time_jiffies);
659 		mutex_unlock(&indio_dev->mlock);
660 		return;
661 	}
662 
663 	ad5933_i2c_read(st->client, AD5933_REG_STATUS, 1, &status);
664 
665 	if (status & AD5933_STAT_DATA_VALID) {
666 		int scan_count = bitmap_weight(indio_dev->active_scan_mask,
667 					       indio_dev->masklength);
668 		ad5933_i2c_read(st->client,
669 				test_bit(1, indio_dev->active_scan_mask) ?
670 				AD5933_REG_REAL_DATA : AD5933_REG_IMAG_DATA,
671 				scan_count * 2, (u8 *)buf);
672 
673 		if (scan_count == 2) {
674 			buf[0] = be16_to_cpu(buf[0]);
675 			buf[1] = be16_to_cpu(buf[1]);
676 		} else {
677 			buf[0] = be16_to_cpu(buf[0]);
678 		}
679 		iio_push_to_buffers(indio_dev, (u8 *)buf);
680 	} else {
681 		/* no data available - try again later */
682 		schedule_delayed_work(&st->work, st->poll_time_jiffies);
683 		mutex_unlock(&indio_dev->mlock);
684 		return;
685 	}
686 
687 	if (status & AD5933_STAT_SWEEP_DONE) {
688 		/* last sample received - power down do nothing until
689 		 * the ring enable is toggled */
690 		ad5933_cmd(st, AD5933_CTRL_POWER_DOWN);
691 	} else {
692 		/* we just received a valid datum, move on to the next */
693 		ad5933_cmd(st, AD5933_CTRL_INC_FREQ);
694 		schedule_delayed_work(&st->work, st->poll_time_jiffies);
695 	}
696 
697 	mutex_unlock(&indio_dev->mlock);
698 }
699 
700 static int ad5933_probe(struct i2c_client *client,
701 				   const struct i2c_device_id *id)
702 {
703 	int ret, voltage_uv = 0;
704 	struct ad5933_platform_data *pdata = client->dev.platform_data;
705 	struct ad5933_state *st;
706 	struct iio_dev *indio_dev = iio_device_alloc(sizeof(*st));
707 	if (indio_dev == NULL)
708 		return -ENOMEM;
709 
710 	st = iio_priv(indio_dev);
711 	i2c_set_clientdata(client, indio_dev);
712 	st->client = client;
713 
714 	if (!pdata)
715 		st->pdata = &ad5933_default_pdata;
716 	else
717 		st->pdata = pdata;
718 
719 	st->reg = regulator_get(&client->dev, "vcc");
720 	if (!IS_ERR(st->reg)) {
721 		ret = regulator_enable(st->reg);
722 		if (ret)
723 			goto error_put_reg;
724 		voltage_uv = regulator_get_voltage(st->reg);
725 	}
726 
727 	if (voltage_uv)
728 		st->vref_mv = voltage_uv / 1000;
729 	else
730 		st->vref_mv = st->pdata->vref_mv;
731 
732 	if (st->pdata->ext_clk_Hz) {
733 		st->mclk_hz = st->pdata->ext_clk_Hz;
734 		st->ctrl_lb = AD5933_CTRL_EXT_SYSCLK;
735 	} else {
736 		st->mclk_hz = AD5933_INT_OSC_FREQ_Hz;
737 		st->ctrl_lb = AD5933_CTRL_INT_SYSCLK;
738 	}
739 
740 	ad5933_calc_out_ranges(st);
741 	INIT_DELAYED_WORK(&st->work, ad5933_work);
742 	st->poll_time_jiffies = msecs_to_jiffies(AD5933_POLL_TIME_ms);
743 
744 	indio_dev->dev.parent = &client->dev;
745 	indio_dev->info = &ad5933_info;
746 	indio_dev->name = id->name;
747 	indio_dev->modes = INDIO_DIRECT_MODE;
748 	indio_dev->channels = ad5933_channels;
749 	indio_dev->num_channels = 1; /* only register temp0_input */
750 
751 	ret = ad5933_register_ring_funcs_and_init(indio_dev);
752 	if (ret)
753 		goto error_disable_reg;
754 
755 	/* skip temp0_input, register in0_(real|imag)_raw */
756 	ret = iio_buffer_register(indio_dev, &ad5933_channels[1], 2);
757 	if (ret)
758 		goto error_unreg_ring;
759 
760 	/* enable both REAL and IMAG channels by default */
761 	iio_scan_mask_set(indio_dev, indio_dev->buffer, 0);
762 	iio_scan_mask_set(indio_dev, indio_dev->buffer, 1);
763 
764 	ret = ad5933_setup(st);
765 	if (ret)
766 		goto error_uninitialize_ring;
767 
768 	ret = iio_device_register(indio_dev);
769 	if (ret)
770 		goto error_uninitialize_ring;
771 
772 	return 0;
773 
774 error_uninitialize_ring:
775 	iio_buffer_unregister(indio_dev);
776 error_unreg_ring:
777 	iio_sw_rb_free(indio_dev->buffer);
778 error_disable_reg:
779 	if (!IS_ERR(st->reg))
780 		regulator_disable(st->reg);
781 error_put_reg:
782 	if (!IS_ERR(st->reg))
783 		regulator_put(st->reg);
784 
785 	iio_device_free(indio_dev);
786 
787 	return ret;
788 }
789 
790 static int ad5933_remove(struct i2c_client *client)
791 {
792 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
793 	struct ad5933_state *st = iio_priv(indio_dev);
794 
795 	iio_device_unregister(indio_dev);
796 	iio_buffer_unregister(indio_dev);
797 	iio_sw_rb_free(indio_dev->buffer);
798 	if (!IS_ERR(st->reg)) {
799 		regulator_disable(st->reg);
800 		regulator_put(st->reg);
801 	}
802 	iio_device_free(indio_dev);
803 
804 	return 0;
805 }
806 
807 static const struct i2c_device_id ad5933_id[] = {
808 	{ "ad5933", 0 },
809 	{ "ad5934", 0 },
810 	{}
811 };
812 
813 MODULE_DEVICE_TABLE(i2c, ad5933_id);
814 
815 static struct i2c_driver ad5933_driver = {
816 	.driver = {
817 		.name = "ad5933",
818 	},
819 	.probe = ad5933_probe,
820 	.remove = ad5933_remove,
821 	.id_table = ad5933_id,
822 };
823 module_i2c_driver(ad5933_driver);
824 
825 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
826 MODULE_DESCRIPTION("Analog Devices AD5933 Impedance Conv. Network Analyzer");
827 MODULE_LICENSE("GPL v2");
828