xref: /openbmc/linux/drivers/iio/dac/ad5446.c (revision e1e0a9e6)
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 	},
136 	IIO_ENUM("powerdown_mode", false, &ad5446_powerdown_mode_enum),
137 	IIO_ENUM_AVAILABLE("powerdown_mode", &ad5446_powerdown_mode_enum),
138 	{ },
139 };
140 
141 #define _AD5446_CHANNEL(bits, storage, shift, ext) { \
142 	.type = IIO_VOLTAGE, \
143 	.indexed = 1, \
144 	.output = 1, \
145 	.channel = 0, \
146 	.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | \
147 	IIO_CHAN_INFO_SCALE_SHARED_BIT,	\
148 	.scan_type = IIO_ST('u', (bits), (storage), (shift)), \
149 	.ext_info = (ext), \
150 }
151 
152 #define AD5446_CHANNEL(bits, storage, shift) \
153 	_AD5446_CHANNEL(bits, storage, shift, NULL)
154 
155 #define AD5446_CHANNEL_POWERDOWN(bits, storage, shift) \
156 	_AD5446_CHANNEL(bits, storage, shift, ad5446_ext_info_powerdown)
157 
158 static int ad5446_read_raw(struct iio_dev *indio_dev,
159 			   struct iio_chan_spec const *chan,
160 			   int *val,
161 			   int *val2,
162 			   long m)
163 {
164 	struct ad5446_state *st = iio_priv(indio_dev);
165 	unsigned long scale_uv;
166 
167 	switch (m) {
168 	case IIO_CHAN_INFO_RAW:
169 		*val = st->cached_val;
170 		return IIO_VAL_INT;
171 	case IIO_CHAN_INFO_SCALE:
172 		scale_uv = (st->vref_mv * 1000) >> chan->scan_type.realbits;
173 		*val =  scale_uv / 1000;
174 		*val2 = (scale_uv % 1000) * 1000;
175 		return IIO_VAL_INT_PLUS_MICRO;
176 
177 	}
178 	return -EINVAL;
179 }
180 
181 static int ad5446_write_raw(struct iio_dev *indio_dev,
182 			       struct iio_chan_spec const *chan,
183 			       int val,
184 			       int val2,
185 			       long mask)
186 {
187 	struct ad5446_state *st = iio_priv(indio_dev);
188 	int ret = 0;
189 
190 	switch (mask) {
191 	case IIO_CHAN_INFO_RAW:
192 		if (val >= (1 << chan->scan_type.realbits) || val < 0)
193 			return -EINVAL;
194 
195 		val <<= chan->scan_type.shift;
196 		mutex_lock(&indio_dev->mlock);
197 		st->cached_val = val;
198 		if (!st->pwr_down)
199 			ret = st->chip_info->write(st, val);
200 		mutex_unlock(&indio_dev->mlock);
201 		break;
202 	default:
203 		ret = -EINVAL;
204 	}
205 
206 	return ret;
207 }
208 
209 static const struct iio_info ad5446_info = {
210 	.read_raw = ad5446_read_raw,
211 	.write_raw = ad5446_write_raw,
212 	.driver_module = THIS_MODULE,
213 };
214 
215 static int ad5446_probe(struct device *dev, const char *name,
216 			const struct ad5446_chip_info *chip_info)
217 {
218 	struct ad5446_state *st;
219 	struct iio_dev *indio_dev;
220 	struct regulator *reg;
221 	int ret, voltage_uv = 0;
222 
223 	reg = regulator_get(dev, "vcc");
224 	if (!IS_ERR(reg)) {
225 		ret = regulator_enable(reg);
226 		if (ret)
227 			goto error_put_reg;
228 
229 		ret = regulator_get_voltage(reg);
230 		if (ret < 0)
231 			goto error_disable_reg;
232 
233 		voltage_uv = ret;
234 	}
235 
236 	indio_dev = iio_device_alloc(sizeof(*st));
237 	if (indio_dev == NULL) {
238 		ret = -ENOMEM;
239 		goto error_disable_reg;
240 	}
241 	st = iio_priv(indio_dev);
242 	st->chip_info = chip_info;
243 
244 	dev_set_drvdata(dev, indio_dev);
245 	st->reg = reg;
246 	st->dev = dev;
247 
248 	/* Establish that the iio_dev is a child of the device */
249 	indio_dev->dev.parent = dev;
250 	indio_dev->name = name;
251 	indio_dev->info = &ad5446_info;
252 	indio_dev->modes = INDIO_DIRECT_MODE;
253 	indio_dev->channels = &st->chip_info->channel;
254 	indio_dev->num_channels = 1;
255 
256 	st->pwr_down_mode = MODE_PWRDWN_1k;
257 
258 	if (st->chip_info->int_vref_mv)
259 		st->vref_mv = st->chip_info->int_vref_mv;
260 	else if (voltage_uv)
261 		st->vref_mv = voltage_uv / 1000;
262 	else
263 		dev_warn(dev, "reference voltage unspecified\n");
264 
265 	ret = iio_device_register(indio_dev);
266 	if (ret)
267 		goto error_free_device;
268 
269 	return 0;
270 
271 error_free_device:
272 	iio_device_free(indio_dev);
273 error_disable_reg:
274 	if (!IS_ERR(reg))
275 		regulator_disable(reg);
276 error_put_reg:
277 	if (!IS_ERR(reg))
278 		regulator_put(reg);
279 
280 	return ret;
281 }
282 
283 static int ad5446_remove(struct device *dev)
284 {
285 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
286 	struct ad5446_state *st = iio_priv(indio_dev);
287 
288 	iio_device_unregister(indio_dev);
289 	if (!IS_ERR(st->reg)) {
290 		regulator_disable(st->reg);
291 		regulator_put(st->reg);
292 	}
293 	iio_device_free(indio_dev);
294 
295 	return 0;
296 }
297 
298 #if IS_ENABLED(CONFIG_SPI_MASTER)
299 
300 static int ad5446_write(struct ad5446_state *st, unsigned val)
301 {
302 	struct spi_device *spi = to_spi_device(st->dev);
303 	__be16 data = cpu_to_be16(val);
304 
305 	return spi_write(spi, &data, sizeof(data));
306 }
307 
308 static int ad5660_write(struct ad5446_state *st, unsigned val)
309 {
310 	struct spi_device *spi = to_spi_device(st->dev);
311 	uint8_t data[3];
312 
313 	data[0] = (val >> 16) & 0xFF;
314 	data[1] = (val >> 8) & 0xFF;
315 	data[2] = val & 0xFF;
316 
317 	return spi_write(spi, data, sizeof(data));
318 }
319 
320 /**
321  * ad5446_supported_spi_device_ids:
322  * The AD5620/40/60 parts are available in different fixed internal reference
323  * voltage options. The actual part numbers may look differently
324  * (and a bit cryptic), however this style is used to make clear which
325  * parts are supported here.
326  */
327 enum ad5446_supported_spi_device_ids {
328 	ID_AD5300,
329 	ID_AD5310,
330 	ID_AD5320,
331 	ID_AD5444,
332 	ID_AD5446,
333 	ID_AD5450,
334 	ID_AD5451,
335 	ID_AD5541A,
336 	ID_AD5512A,
337 	ID_AD5553,
338 	ID_AD5601,
339 	ID_AD5611,
340 	ID_AD5621,
341 	ID_AD5620_2500,
342 	ID_AD5620_1250,
343 	ID_AD5640_2500,
344 	ID_AD5640_1250,
345 	ID_AD5660_2500,
346 	ID_AD5660_1250,
347 	ID_AD5662,
348 };
349 
350 static const struct ad5446_chip_info ad5446_spi_chip_info[] = {
351 	[ID_AD5300] = {
352 		.channel = AD5446_CHANNEL_POWERDOWN(8, 16, 4),
353 		.write = ad5446_write,
354 	},
355 	[ID_AD5310] = {
356 		.channel = AD5446_CHANNEL_POWERDOWN(10, 16, 2),
357 		.write = ad5446_write,
358 	},
359 	[ID_AD5320] = {
360 		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 0),
361 		.write = ad5446_write,
362 	},
363 	[ID_AD5444] = {
364 		.channel = AD5446_CHANNEL(12, 16, 2),
365 		.write = ad5446_write,
366 	},
367 	[ID_AD5446] = {
368 		.channel = AD5446_CHANNEL(14, 16, 0),
369 		.write = ad5446_write,
370 	},
371 	[ID_AD5450] = {
372 		.channel = AD5446_CHANNEL(8, 16, 6),
373 		.write = ad5446_write,
374 	},
375 	[ID_AD5451] = {
376 		.channel = AD5446_CHANNEL(10, 16, 4),
377 		.write = ad5446_write,
378 	},
379 	[ID_AD5541A] = {
380 		.channel = AD5446_CHANNEL(16, 16, 0),
381 		.write = ad5446_write,
382 	},
383 	[ID_AD5512A] = {
384 		.channel = AD5446_CHANNEL(12, 16, 4),
385 		.write = ad5446_write,
386 	},
387 	[ID_AD5553] = {
388 		.channel = AD5446_CHANNEL(14, 16, 0),
389 		.write = ad5446_write,
390 	},
391 	[ID_AD5601] = {
392 		.channel = AD5446_CHANNEL_POWERDOWN(8, 16, 6),
393 		.write = ad5446_write,
394 	},
395 	[ID_AD5611] = {
396 		.channel = AD5446_CHANNEL_POWERDOWN(10, 16, 4),
397 		.write = ad5446_write,
398 	},
399 	[ID_AD5621] = {
400 		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 2),
401 		.write = ad5446_write,
402 	},
403 	[ID_AD5620_2500] = {
404 		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 2),
405 		.int_vref_mv = 2500,
406 		.write = ad5446_write,
407 	},
408 	[ID_AD5620_1250] = {
409 		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 2),
410 		.int_vref_mv = 1250,
411 		.write = ad5446_write,
412 	},
413 	[ID_AD5640_2500] = {
414 		.channel = AD5446_CHANNEL_POWERDOWN(14, 16, 0),
415 		.int_vref_mv = 2500,
416 		.write = ad5446_write,
417 	},
418 	[ID_AD5640_1250] = {
419 		.channel = AD5446_CHANNEL_POWERDOWN(14, 16, 0),
420 		.int_vref_mv = 1250,
421 		.write = ad5446_write,
422 	},
423 	[ID_AD5660_2500] = {
424 		.channel = AD5446_CHANNEL_POWERDOWN(16, 16, 0),
425 		.int_vref_mv = 2500,
426 		.write = ad5660_write,
427 	},
428 	[ID_AD5660_1250] = {
429 		.channel = AD5446_CHANNEL_POWERDOWN(16, 16, 0),
430 		.int_vref_mv = 1250,
431 		.write = ad5660_write,
432 	},
433 	[ID_AD5662] = {
434 		.channel = AD5446_CHANNEL_POWERDOWN(16, 16, 0),
435 		.write = ad5660_write,
436 	},
437 };
438 
439 static const struct spi_device_id ad5446_spi_ids[] = {
440 	{"ad5300", ID_AD5300},
441 	{"ad5310", ID_AD5310},
442 	{"ad5320", ID_AD5320},
443 	{"ad5444", ID_AD5444},
444 	{"ad5446", ID_AD5446},
445 	{"ad5450", ID_AD5450},
446 	{"ad5451", ID_AD5451},
447 	{"ad5452", ID_AD5444}, /* ad5452 is compatible to the ad5444 */
448 	{"ad5453", ID_AD5446}, /* ad5453 is compatible to the ad5446 */
449 	{"ad5512a", ID_AD5512A},
450 	{"ad5541a", ID_AD5541A},
451 	{"ad5542a", ID_AD5541A}, /* ad5541a and ad5542a are compatible */
452 	{"ad5543", ID_AD5541A}, /* ad5541a and ad5543 are compatible */
453 	{"ad5553", ID_AD5553},
454 	{"ad5601", ID_AD5601},
455 	{"ad5611", ID_AD5611},
456 	{"ad5621", ID_AD5621},
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 		.owner	= THIS_MODULE,
485 	},
486 	.probe		= ad5446_spi_probe,
487 	.remove		= ad5446_spi_remove,
488 	.id_table	= ad5446_spi_ids,
489 };
490 
491 static int __init ad5446_spi_register_driver(void)
492 {
493 	return spi_register_driver(&ad5446_spi_driver);
494 }
495 
496 static void ad5446_spi_unregister_driver(void)
497 {
498 	spi_unregister_driver(&ad5446_spi_driver);
499 }
500 
501 #else
502 
503 static inline int ad5446_spi_register_driver(void) { return 0; }
504 static inline void ad5446_spi_unregister_driver(void) { }
505 
506 #endif
507 
508 #if IS_ENABLED(CONFIG_I2C)
509 
510 static int ad5622_write(struct ad5446_state *st, unsigned val)
511 {
512 	struct i2c_client *client = to_i2c_client(st->dev);
513 	__be16 data = cpu_to_be16(val);
514 
515 	return i2c_master_send(client, (char *)&data, sizeof(data));
516 }
517 
518 /**
519  * ad5446_supported_i2c_device_ids:
520  * The AD5620/40/60 parts are available in different fixed internal reference
521  * voltage options. The actual part numbers may look differently
522  * (and a bit cryptic), however this style is used to make clear which
523  * parts are supported here.
524  */
525 enum ad5446_supported_i2c_device_ids {
526 	ID_AD5602,
527 	ID_AD5612,
528 	ID_AD5622,
529 };
530 
531 static const struct ad5446_chip_info ad5446_i2c_chip_info[] = {
532 	[ID_AD5602] = {
533 		.channel = AD5446_CHANNEL_POWERDOWN(8, 16, 4),
534 		.write = ad5622_write,
535 	},
536 	[ID_AD5612] = {
537 		.channel = AD5446_CHANNEL_POWERDOWN(10, 16, 2),
538 		.write = ad5622_write,
539 	},
540 	[ID_AD5622] = {
541 		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 0),
542 		.write = ad5622_write,
543 	},
544 };
545 
546 static int ad5446_i2c_probe(struct i2c_client *i2c,
547 			    const struct i2c_device_id *id)
548 {
549 	return ad5446_probe(&i2c->dev, id->name,
550 		&ad5446_i2c_chip_info[id->driver_data]);
551 }
552 
553 static int ad5446_i2c_remove(struct i2c_client *i2c)
554 {
555 	return ad5446_remove(&i2c->dev);
556 }
557 
558 static const struct i2c_device_id ad5446_i2c_ids[] = {
559 	{"ad5301", ID_AD5602},
560 	{"ad5311", ID_AD5612},
561 	{"ad5321", ID_AD5622},
562 	{"ad5602", ID_AD5602},
563 	{"ad5612", ID_AD5612},
564 	{"ad5622", ID_AD5622},
565 	{}
566 };
567 MODULE_DEVICE_TABLE(i2c, ad5446_i2c_ids);
568 
569 static struct i2c_driver ad5446_i2c_driver = {
570 	.driver = {
571 		   .name = "ad5446",
572 		   .owner = THIS_MODULE,
573 	},
574 	.probe = ad5446_i2c_probe,
575 	.remove = ad5446_i2c_remove,
576 	.id_table = ad5446_i2c_ids,
577 };
578 
579 static int __init ad5446_i2c_register_driver(void)
580 {
581 	return i2c_add_driver(&ad5446_i2c_driver);
582 }
583 
584 static void __exit ad5446_i2c_unregister_driver(void)
585 {
586 	i2c_del_driver(&ad5446_i2c_driver);
587 }
588 
589 #else
590 
591 static inline int ad5446_i2c_register_driver(void) { return 0; }
592 static inline void ad5446_i2c_unregister_driver(void) { }
593 
594 #endif
595 
596 static int __init ad5446_init(void)
597 {
598 	int ret;
599 
600 	ret = ad5446_spi_register_driver();
601 	if (ret)
602 		return ret;
603 
604 	ret = ad5446_i2c_register_driver();
605 	if (ret) {
606 		ad5446_spi_unregister_driver();
607 		return ret;
608 	}
609 
610 	return 0;
611 }
612 module_init(ad5446_init);
613 
614 static void __exit ad5446_exit(void)
615 {
616 	ad5446_i2c_unregister_driver();
617 	ad5446_spi_unregister_driver();
618 }
619 module_exit(ad5446_exit);
620 
621 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
622 MODULE_DESCRIPTION("Analog Devices AD5444/AD5446 DAC");
623 MODULE_LICENSE("GPL v2");
624