xref: /openbmc/linux/drivers/iio/dac/ad5446.c (revision f3539c12)
1 /*
2  * AD5446 SPI DAC driver
3  *
4  * Copyright 2010 Analog Devices Inc.
5  *
6  * Licensed under the GPL-2 or later.
7  */
8 
9 #include <linux/interrupt.h>
10 #include <linux/workqueue.h>
11 #include <linux/device.h>
12 #include <linux/kernel.h>
13 #include <linux/slab.h>
14 #include <linux/sysfs.h>
15 #include <linux/list.h>
16 #include <linux/spi/spi.h>
17 #include <linux/i2c.h>
18 #include <linux/regulator/consumer.h>
19 #include <linux/err.h>
20 #include <linux/module.h>
21 
22 #include <linux/iio/iio.h>
23 #include <linux/iio/sysfs.h>
24 
25 #define MODE_PWRDWN_1k		0x1
26 #define MODE_PWRDWN_100k	0x2
27 #define MODE_PWRDWN_TRISTATE	0x3
28 
29 /**
30  * struct ad5446_state - driver instance specific data
31  * @spi:		spi_device
32  * @chip_info:		chip model specific constants, available modes etc
33  * @reg:		supply regulator
34  * @vref_mv:		actual reference voltage used
35  */
36 
37 struct ad5446_state {
38 	struct device		*dev;
39 	const struct ad5446_chip_info	*chip_info;
40 	struct regulator		*reg;
41 	unsigned short			vref_mv;
42 	unsigned			cached_val;
43 	unsigned			pwr_down_mode;
44 	unsigned			pwr_down;
45 };
46 
47 /**
48  * struct ad5446_chip_info - chip specific information
49  * @channel:		channel spec for the DAC
50  * @int_vref_mv:	AD5620/40/60: the internal reference voltage
51  * @write:		chip specific helper function to write to the register
52  */
53 
54 struct ad5446_chip_info {
55 	struct iio_chan_spec	channel;
56 	u16			int_vref_mv;
57 	int			(*write)(struct ad5446_state *st, unsigned val);
58 };
59 
60 static const char * const ad5446_powerdown_modes[] = {
61 	"1kohm_to_gnd", "100kohm_to_gnd", "three_state"
62 };
63 
64 static int ad5446_set_powerdown_mode(struct iio_dev *indio_dev,
65 	const struct iio_chan_spec *chan, unsigned int mode)
66 {
67 	struct ad5446_state *st = iio_priv(indio_dev);
68 
69 	st->pwr_down_mode = mode + 1;
70 
71 	return 0;
72 }
73 
74 static int ad5446_get_powerdown_mode(struct iio_dev *indio_dev,
75 	const struct iio_chan_spec *chan)
76 {
77 	struct ad5446_state *st = iio_priv(indio_dev);
78 
79 	return st->pwr_down_mode - 1;
80 }
81 
82 static const struct iio_enum ad5446_powerdown_mode_enum = {
83 	.items = ad5446_powerdown_modes,
84 	.num_items = ARRAY_SIZE(ad5446_powerdown_modes),
85 	.get = ad5446_get_powerdown_mode,
86 	.set = ad5446_set_powerdown_mode,
87 };
88 
89 static ssize_t ad5446_read_dac_powerdown(struct iio_dev *indio_dev,
90 					   uintptr_t private,
91 					   const struct iio_chan_spec *chan,
92 					   char *buf)
93 {
94 	struct ad5446_state *st = iio_priv(indio_dev);
95 
96 	return sprintf(buf, "%d\n", st->pwr_down);
97 }
98 
99 static ssize_t ad5446_write_dac_powerdown(struct iio_dev *indio_dev,
100 					    uintptr_t private,
101 					    const struct iio_chan_spec *chan,
102 					    const char *buf, size_t len)
103 {
104 	struct ad5446_state *st = iio_priv(indio_dev);
105 	unsigned int shift;
106 	unsigned int val;
107 	bool powerdown;
108 	int ret;
109 
110 	ret = strtobool(buf, &powerdown);
111 	if (ret)
112 		return ret;
113 
114 	mutex_lock(&indio_dev->mlock);
115 	st->pwr_down = powerdown;
116 
117 	if (st->pwr_down) {
118 		shift = chan->scan_type.realbits + chan->scan_type.shift;
119 		val = st->pwr_down_mode << shift;
120 	} else {
121 		val = st->cached_val;
122 	}
123 
124 	ret = st->chip_info->write(st, val);
125 	mutex_unlock(&indio_dev->mlock);
126 
127 	return ret ? ret : len;
128 }
129 
130 static const struct iio_chan_spec_ext_info ad5446_ext_info_powerdown[] = {
131 	{
132 		.name = "powerdown",
133 		.read = ad5446_read_dac_powerdown,
134 		.write = ad5446_write_dac_powerdown,
135 		.shared = IIO_SEPARATE,
136 	},
137 	IIO_ENUM("powerdown_mode", IIO_SEPARATE, &ad5446_powerdown_mode_enum),
138 	IIO_ENUM_AVAILABLE("powerdown_mode", &ad5446_powerdown_mode_enum),
139 	{ },
140 };
141 
142 #define _AD5446_CHANNEL(bits, storage, _shift, ext) { \
143 	.type = IIO_VOLTAGE, \
144 	.indexed = 1, \
145 	.output = 1, \
146 	.channel = 0, \
147 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
148 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
149 	.scan_type = { \
150 		.sign = 'u', \
151 		.realbits = (bits), \
152 		.storagebits = (storage), \
153 		.shift = (_shift), \
154 		}, \
155 	.ext_info = (ext), \
156 }
157 
158 #define AD5446_CHANNEL(bits, storage, shift) \
159 	_AD5446_CHANNEL(bits, storage, shift, NULL)
160 
161 #define AD5446_CHANNEL_POWERDOWN(bits, storage, shift) \
162 	_AD5446_CHANNEL(bits, storage, shift, ad5446_ext_info_powerdown)
163 
164 static int ad5446_read_raw(struct iio_dev *indio_dev,
165 			   struct iio_chan_spec const *chan,
166 			   int *val,
167 			   int *val2,
168 			   long m)
169 {
170 	struct ad5446_state *st = iio_priv(indio_dev);
171 
172 	switch (m) {
173 	case IIO_CHAN_INFO_RAW:
174 		*val = st->cached_val;
175 		return IIO_VAL_INT;
176 	case IIO_CHAN_INFO_SCALE:
177 		*val = st->vref_mv;
178 		*val2 = chan->scan_type.realbits;
179 		return IIO_VAL_FRACTIONAL_LOG2;
180 	}
181 	return -EINVAL;
182 }
183 
184 static int ad5446_write_raw(struct iio_dev *indio_dev,
185 			       struct iio_chan_spec const *chan,
186 			       int val,
187 			       int val2,
188 			       long mask)
189 {
190 	struct ad5446_state *st = iio_priv(indio_dev);
191 	int ret = 0;
192 
193 	switch (mask) {
194 	case IIO_CHAN_INFO_RAW:
195 		if (val >= (1 << chan->scan_type.realbits) || val < 0)
196 			return -EINVAL;
197 
198 		val <<= chan->scan_type.shift;
199 		mutex_lock(&indio_dev->mlock);
200 		st->cached_val = val;
201 		if (!st->pwr_down)
202 			ret = st->chip_info->write(st, val);
203 		mutex_unlock(&indio_dev->mlock);
204 		break;
205 	default:
206 		ret = -EINVAL;
207 	}
208 
209 	return ret;
210 }
211 
212 static const struct iio_info ad5446_info = {
213 	.read_raw = ad5446_read_raw,
214 	.write_raw = ad5446_write_raw,
215 	.driver_module = THIS_MODULE,
216 };
217 
218 static int ad5446_probe(struct device *dev, const char *name,
219 			const struct ad5446_chip_info *chip_info)
220 {
221 	struct ad5446_state *st;
222 	struct iio_dev *indio_dev;
223 	struct regulator *reg;
224 	int ret, voltage_uv = 0;
225 
226 	reg = devm_regulator_get(dev, "vcc");
227 	if (!IS_ERR(reg)) {
228 		ret = regulator_enable(reg);
229 		if (ret)
230 			return ret;
231 
232 		ret = regulator_get_voltage(reg);
233 		if (ret < 0)
234 			goto error_disable_reg;
235 
236 		voltage_uv = ret;
237 	}
238 
239 	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
240 	if (indio_dev == NULL) {
241 		ret = -ENOMEM;
242 		goto error_disable_reg;
243 	}
244 	st = iio_priv(indio_dev);
245 	st->chip_info = chip_info;
246 
247 	dev_set_drvdata(dev, indio_dev);
248 	st->reg = reg;
249 	st->dev = dev;
250 
251 	/* Establish that the iio_dev is a child of the device */
252 	indio_dev->dev.parent = dev;
253 	indio_dev->name = name;
254 	indio_dev->info = &ad5446_info;
255 	indio_dev->modes = INDIO_DIRECT_MODE;
256 	indio_dev->channels = &st->chip_info->channel;
257 	indio_dev->num_channels = 1;
258 
259 	st->pwr_down_mode = MODE_PWRDWN_1k;
260 
261 	if (st->chip_info->int_vref_mv)
262 		st->vref_mv = st->chip_info->int_vref_mv;
263 	else if (voltage_uv)
264 		st->vref_mv = voltage_uv / 1000;
265 	else
266 		dev_warn(dev, "reference voltage unspecified\n");
267 
268 	ret = iio_device_register(indio_dev);
269 	if (ret)
270 		goto error_disable_reg;
271 
272 	return 0;
273 
274 error_disable_reg:
275 	if (!IS_ERR(reg))
276 		regulator_disable(reg);
277 	return ret;
278 }
279 
280 static int ad5446_remove(struct device *dev)
281 {
282 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
283 	struct ad5446_state *st = iio_priv(indio_dev);
284 
285 	iio_device_unregister(indio_dev);
286 	if (!IS_ERR(st->reg))
287 		regulator_disable(st->reg);
288 
289 	return 0;
290 }
291 
292 #if IS_ENABLED(CONFIG_SPI_MASTER)
293 
294 static int ad5446_write(struct ad5446_state *st, unsigned val)
295 {
296 	struct spi_device *spi = to_spi_device(st->dev);
297 	__be16 data = cpu_to_be16(val);
298 
299 	return spi_write(spi, &data, sizeof(data));
300 }
301 
302 static int ad5660_write(struct ad5446_state *st, unsigned val)
303 {
304 	struct spi_device *spi = to_spi_device(st->dev);
305 	uint8_t data[3];
306 
307 	data[0] = (val >> 16) & 0xFF;
308 	data[1] = (val >> 8) & 0xFF;
309 	data[2] = val & 0xFF;
310 
311 	return spi_write(spi, data, sizeof(data));
312 }
313 
314 /**
315  * ad5446_supported_spi_device_ids:
316  * The AD5620/40/60 parts are available in different fixed internal reference
317  * voltage options. The actual part numbers may look differently
318  * (and a bit cryptic), however this style is used to make clear which
319  * parts are supported here.
320  */
321 enum ad5446_supported_spi_device_ids {
322 	ID_AD5300,
323 	ID_AD5310,
324 	ID_AD5320,
325 	ID_AD5444,
326 	ID_AD5446,
327 	ID_AD5450,
328 	ID_AD5451,
329 	ID_AD5541A,
330 	ID_AD5512A,
331 	ID_AD5553,
332 	ID_AD5601,
333 	ID_AD5611,
334 	ID_AD5621,
335 	ID_AD5641,
336 	ID_AD5620_2500,
337 	ID_AD5620_1250,
338 	ID_AD5640_2500,
339 	ID_AD5640_1250,
340 	ID_AD5660_2500,
341 	ID_AD5660_1250,
342 	ID_AD5662,
343 };
344 
345 static const struct ad5446_chip_info ad5446_spi_chip_info[] = {
346 	[ID_AD5300] = {
347 		.channel = AD5446_CHANNEL_POWERDOWN(8, 16, 4),
348 		.write = ad5446_write,
349 	},
350 	[ID_AD5310] = {
351 		.channel = AD5446_CHANNEL_POWERDOWN(10, 16, 2),
352 		.write = ad5446_write,
353 	},
354 	[ID_AD5320] = {
355 		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 0),
356 		.write = ad5446_write,
357 	},
358 	[ID_AD5444] = {
359 		.channel = AD5446_CHANNEL(12, 16, 2),
360 		.write = ad5446_write,
361 	},
362 	[ID_AD5446] = {
363 		.channel = AD5446_CHANNEL(14, 16, 0),
364 		.write = ad5446_write,
365 	},
366 	[ID_AD5450] = {
367 		.channel = AD5446_CHANNEL(8, 16, 6),
368 		.write = ad5446_write,
369 	},
370 	[ID_AD5451] = {
371 		.channel = AD5446_CHANNEL(10, 16, 4),
372 		.write = ad5446_write,
373 	},
374 	[ID_AD5541A] = {
375 		.channel = AD5446_CHANNEL(16, 16, 0),
376 		.write = ad5446_write,
377 	},
378 	[ID_AD5512A] = {
379 		.channel = AD5446_CHANNEL(12, 16, 4),
380 		.write = ad5446_write,
381 	},
382 	[ID_AD5553] = {
383 		.channel = AD5446_CHANNEL(14, 16, 0),
384 		.write = ad5446_write,
385 	},
386 	[ID_AD5601] = {
387 		.channel = AD5446_CHANNEL_POWERDOWN(8, 16, 6),
388 		.write = ad5446_write,
389 	},
390 	[ID_AD5611] = {
391 		.channel = AD5446_CHANNEL_POWERDOWN(10, 16, 4),
392 		.write = ad5446_write,
393 	},
394 	[ID_AD5621] = {
395 		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 2),
396 		.write = ad5446_write,
397 	},
398 	[ID_AD5641] = {
399 		.channel = AD5446_CHANNEL_POWERDOWN(14, 16, 0),
400 		.write = ad5446_write,
401 	},
402 	[ID_AD5620_2500] = {
403 		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 2),
404 		.int_vref_mv = 2500,
405 		.write = ad5446_write,
406 	},
407 	[ID_AD5620_1250] = {
408 		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 2),
409 		.int_vref_mv = 1250,
410 		.write = ad5446_write,
411 	},
412 	[ID_AD5640_2500] = {
413 		.channel = AD5446_CHANNEL_POWERDOWN(14, 16, 0),
414 		.int_vref_mv = 2500,
415 		.write = ad5446_write,
416 	},
417 	[ID_AD5640_1250] = {
418 		.channel = AD5446_CHANNEL_POWERDOWN(14, 16, 0),
419 		.int_vref_mv = 1250,
420 		.write = ad5446_write,
421 	},
422 	[ID_AD5660_2500] = {
423 		.channel = AD5446_CHANNEL_POWERDOWN(16, 16, 0),
424 		.int_vref_mv = 2500,
425 		.write = ad5660_write,
426 	},
427 	[ID_AD5660_1250] = {
428 		.channel = AD5446_CHANNEL_POWERDOWN(16, 16, 0),
429 		.int_vref_mv = 1250,
430 		.write = ad5660_write,
431 	},
432 	[ID_AD5662] = {
433 		.channel = AD5446_CHANNEL_POWERDOWN(16, 16, 0),
434 		.write = ad5660_write,
435 	},
436 };
437 
438 static const struct spi_device_id ad5446_spi_ids[] = {
439 	{"ad5300", ID_AD5300},
440 	{"ad5310", ID_AD5310},
441 	{"ad5320", ID_AD5320},
442 	{"ad5444", ID_AD5444},
443 	{"ad5446", ID_AD5446},
444 	{"ad5450", ID_AD5450},
445 	{"ad5451", ID_AD5451},
446 	{"ad5452", ID_AD5444}, /* ad5452 is compatible to the ad5444 */
447 	{"ad5453", ID_AD5446}, /* ad5453 is compatible to the ad5446 */
448 	{"ad5512a", ID_AD5512A},
449 	{"ad5541a", ID_AD5541A},
450 	{"ad5542a", ID_AD5541A}, /* ad5541a and ad5542a are compatible */
451 	{"ad5543", ID_AD5541A}, /* ad5541a and ad5543 are compatible */
452 	{"ad5553", ID_AD5553},
453 	{"ad5601", ID_AD5601},
454 	{"ad5611", ID_AD5611},
455 	{"ad5621", ID_AD5621},
456 	{"ad5641", ID_AD5641},
457 	{"ad5620-2500", ID_AD5620_2500}, /* AD5620/40/60: */
458 	{"ad5620-1250", ID_AD5620_1250}, /* part numbers may look differently */
459 	{"ad5640-2500", ID_AD5640_2500},
460 	{"ad5640-1250", ID_AD5640_1250},
461 	{"ad5660-2500", ID_AD5660_2500},
462 	{"ad5660-1250", ID_AD5660_1250},
463 	{"ad5662", ID_AD5662},
464 	{}
465 };
466 MODULE_DEVICE_TABLE(spi, ad5446_spi_ids);
467 
468 static int ad5446_spi_probe(struct spi_device *spi)
469 {
470 	const struct spi_device_id *id = spi_get_device_id(spi);
471 
472 	return ad5446_probe(&spi->dev, id->name,
473 		&ad5446_spi_chip_info[id->driver_data]);
474 }
475 
476 static int ad5446_spi_remove(struct spi_device *spi)
477 {
478 	return ad5446_remove(&spi->dev);
479 }
480 
481 static struct spi_driver ad5446_spi_driver = {
482 	.driver = {
483 		.name	= "ad5446",
484 	},
485 	.probe		= ad5446_spi_probe,
486 	.remove		= ad5446_spi_remove,
487 	.id_table	= ad5446_spi_ids,
488 };
489 
490 static int __init ad5446_spi_register_driver(void)
491 {
492 	return spi_register_driver(&ad5446_spi_driver);
493 }
494 
495 static void ad5446_spi_unregister_driver(void)
496 {
497 	spi_unregister_driver(&ad5446_spi_driver);
498 }
499 
500 #else
501 
502 static inline int ad5446_spi_register_driver(void) { return 0; }
503 static inline void ad5446_spi_unregister_driver(void) { }
504 
505 #endif
506 
507 #if IS_ENABLED(CONFIG_I2C)
508 
509 static int ad5622_write(struct ad5446_state *st, unsigned val)
510 {
511 	struct i2c_client *client = to_i2c_client(st->dev);
512 	__be16 data = cpu_to_be16(val);
513 
514 	return i2c_master_send(client, (char *)&data, sizeof(data));
515 }
516 
517 /**
518  * ad5446_supported_i2c_device_ids:
519  * The AD5620/40/60 parts are available in different fixed internal reference
520  * voltage options. The actual part numbers may look differently
521  * (and a bit cryptic), however this style is used to make clear which
522  * parts are supported here.
523  */
524 enum ad5446_supported_i2c_device_ids {
525 	ID_AD5602,
526 	ID_AD5612,
527 	ID_AD5622,
528 };
529 
530 static const struct ad5446_chip_info ad5446_i2c_chip_info[] = {
531 	[ID_AD5602] = {
532 		.channel = AD5446_CHANNEL_POWERDOWN(8, 16, 4),
533 		.write = ad5622_write,
534 	},
535 	[ID_AD5612] = {
536 		.channel = AD5446_CHANNEL_POWERDOWN(10, 16, 2),
537 		.write = ad5622_write,
538 	},
539 	[ID_AD5622] = {
540 		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 0),
541 		.write = ad5622_write,
542 	},
543 };
544 
545 static int ad5446_i2c_probe(struct i2c_client *i2c,
546 			    const struct i2c_device_id *id)
547 {
548 	return ad5446_probe(&i2c->dev, id->name,
549 		&ad5446_i2c_chip_info[id->driver_data]);
550 }
551 
552 static int ad5446_i2c_remove(struct i2c_client *i2c)
553 {
554 	return ad5446_remove(&i2c->dev);
555 }
556 
557 static const struct i2c_device_id ad5446_i2c_ids[] = {
558 	{"ad5301", ID_AD5602},
559 	{"ad5311", ID_AD5612},
560 	{"ad5321", ID_AD5622},
561 	{"ad5602", ID_AD5602},
562 	{"ad5612", ID_AD5612},
563 	{"ad5622", ID_AD5622},
564 	{}
565 };
566 MODULE_DEVICE_TABLE(i2c, ad5446_i2c_ids);
567 
568 static struct i2c_driver ad5446_i2c_driver = {
569 	.driver = {
570 		   .name = "ad5446",
571 	},
572 	.probe = ad5446_i2c_probe,
573 	.remove = ad5446_i2c_remove,
574 	.id_table = ad5446_i2c_ids,
575 };
576 
577 static int __init ad5446_i2c_register_driver(void)
578 {
579 	return i2c_add_driver(&ad5446_i2c_driver);
580 }
581 
582 static void __exit ad5446_i2c_unregister_driver(void)
583 {
584 	i2c_del_driver(&ad5446_i2c_driver);
585 }
586 
587 #else
588 
589 static inline int ad5446_i2c_register_driver(void) { return 0; }
590 static inline void ad5446_i2c_unregister_driver(void) { }
591 
592 #endif
593 
594 static int __init ad5446_init(void)
595 {
596 	int ret;
597 
598 	ret = ad5446_spi_register_driver();
599 	if (ret)
600 		return ret;
601 
602 	ret = ad5446_i2c_register_driver();
603 	if (ret) {
604 		ad5446_spi_unregister_driver();
605 		return ret;
606 	}
607 
608 	return 0;
609 }
610 module_init(ad5446_init);
611 
612 static void __exit ad5446_exit(void)
613 {
614 	ad5446_i2c_unregister_driver();
615 	ad5446_spi_unregister_driver();
616 }
617 module_exit(ad5446_exit);
618 
619 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
620 MODULE_DESCRIPTION("Analog Devices AD5444/AD5446 DAC");
621 MODULE_LICENSE("GPL v2");
622