xref: /openbmc/linux/drivers/iio/dac/ad5446.c (revision 8fdff1dc)
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 		voltage_uv = regulator_get_voltage(reg);
230 	}
231 
232 	indio_dev = iio_device_alloc(sizeof(*st));
233 	if (indio_dev == NULL) {
234 		ret = -ENOMEM;
235 		goto error_disable_reg;
236 	}
237 	st = iio_priv(indio_dev);
238 	st->chip_info = chip_info;
239 
240 	dev_set_drvdata(dev, indio_dev);
241 	st->reg = reg;
242 	st->dev = dev;
243 
244 	/* Establish that the iio_dev is a child of the device */
245 	indio_dev->dev.parent = dev;
246 	indio_dev->name = name;
247 	indio_dev->info = &ad5446_info;
248 	indio_dev->modes = INDIO_DIRECT_MODE;
249 	indio_dev->channels = &st->chip_info->channel;
250 	indio_dev->num_channels = 1;
251 
252 	st->pwr_down_mode = MODE_PWRDWN_1k;
253 
254 	if (st->chip_info->int_vref_mv)
255 		st->vref_mv = st->chip_info->int_vref_mv;
256 	else if (voltage_uv)
257 		st->vref_mv = voltage_uv / 1000;
258 	else
259 		dev_warn(dev, "reference voltage unspecified\n");
260 
261 	ret = iio_device_register(indio_dev);
262 	if (ret)
263 		goto error_free_device;
264 
265 	return 0;
266 
267 error_free_device:
268 	iio_device_free(indio_dev);
269 error_disable_reg:
270 	if (!IS_ERR(reg))
271 		regulator_disable(reg);
272 error_put_reg:
273 	if (!IS_ERR(reg))
274 		regulator_put(reg);
275 
276 	return ret;
277 }
278 
279 static int ad5446_remove(struct device *dev)
280 {
281 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
282 	struct ad5446_state *st = iio_priv(indio_dev);
283 
284 	iio_device_unregister(indio_dev);
285 	if (!IS_ERR(st->reg)) {
286 		regulator_disable(st->reg);
287 		regulator_put(st->reg);
288 	}
289 	iio_device_free(indio_dev);
290 
291 	return 0;
292 }
293 
294 #if IS_ENABLED(CONFIG_SPI_MASTER)
295 
296 static int ad5446_write(struct ad5446_state *st, unsigned val)
297 {
298 	struct spi_device *spi = to_spi_device(st->dev);
299 	__be16 data = cpu_to_be16(val);
300 
301 	return spi_write(spi, &data, sizeof(data));
302 }
303 
304 static int ad5660_write(struct ad5446_state *st, unsigned val)
305 {
306 	struct spi_device *spi = to_spi_device(st->dev);
307 	uint8_t data[3];
308 
309 	data[0] = (val >> 16) & 0xFF;
310 	data[1] = (val >> 8) & 0xFF;
311 	data[2] = val & 0xFF;
312 
313 	return spi_write(spi, data, sizeof(data));
314 }
315 
316 /**
317  * ad5446_supported_spi_device_ids:
318  * The AD5620/40/60 parts are available in different fixed internal reference
319  * voltage options. The actual part numbers may look differently
320  * (and a bit cryptic), however this style is used to make clear which
321  * parts are supported here.
322  */
323 enum ad5446_supported_spi_device_ids {
324 	ID_AD5300,
325 	ID_AD5310,
326 	ID_AD5320,
327 	ID_AD5444,
328 	ID_AD5446,
329 	ID_AD5450,
330 	ID_AD5451,
331 	ID_AD5541A,
332 	ID_AD5512A,
333 	ID_AD5553,
334 	ID_AD5601,
335 	ID_AD5611,
336 	ID_AD5621,
337 	ID_AD5620_2500,
338 	ID_AD5620_1250,
339 	ID_AD5640_2500,
340 	ID_AD5640_1250,
341 	ID_AD5660_2500,
342 	ID_AD5660_1250,
343 	ID_AD5662,
344 };
345 
346 static const struct ad5446_chip_info ad5446_spi_chip_info[] = {
347 	[ID_AD5300] = {
348 		.channel = AD5446_CHANNEL_POWERDOWN(8, 16, 4),
349 		.write = ad5446_write,
350 	},
351 	[ID_AD5310] = {
352 		.channel = AD5446_CHANNEL_POWERDOWN(10, 16, 2),
353 		.write = ad5446_write,
354 	},
355 	[ID_AD5320] = {
356 		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 0),
357 		.write = ad5446_write,
358 	},
359 	[ID_AD5444] = {
360 		.channel = AD5446_CHANNEL(12, 16, 2),
361 		.write = ad5446_write,
362 	},
363 	[ID_AD5446] = {
364 		.channel = AD5446_CHANNEL(14, 16, 0),
365 		.write = ad5446_write,
366 	},
367 	[ID_AD5450] = {
368 		.channel = AD5446_CHANNEL(8, 16, 6),
369 		.write = ad5446_write,
370 	},
371 	[ID_AD5451] = {
372 		.channel = AD5446_CHANNEL(10, 16, 4),
373 		.write = ad5446_write,
374 	},
375 	[ID_AD5541A] = {
376 		.channel = AD5446_CHANNEL(16, 16, 0),
377 		.write = ad5446_write,
378 	},
379 	[ID_AD5512A] = {
380 		.channel = AD5446_CHANNEL(12, 16, 4),
381 		.write = ad5446_write,
382 	},
383 	[ID_AD5553] = {
384 		.channel = AD5446_CHANNEL(14, 16, 0),
385 		.write = ad5446_write,
386 	},
387 	[ID_AD5601] = {
388 		.channel = AD5446_CHANNEL_POWERDOWN(8, 16, 6),
389 		.write = ad5446_write,
390 	},
391 	[ID_AD5611] = {
392 		.channel = AD5446_CHANNEL_POWERDOWN(10, 16, 4),
393 		.write = ad5446_write,
394 	},
395 	[ID_AD5621] = {
396 		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 2),
397 		.write = ad5446_write,
398 	},
399 	[ID_AD5620_2500] = {
400 		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 2),
401 		.int_vref_mv = 2500,
402 		.write = ad5446_write,
403 	},
404 	[ID_AD5620_1250] = {
405 		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 2),
406 		.int_vref_mv = 1250,
407 		.write = ad5446_write,
408 	},
409 	[ID_AD5640_2500] = {
410 		.channel = AD5446_CHANNEL_POWERDOWN(14, 16, 0),
411 		.int_vref_mv = 2500,
412 		.write = ad5446_write,
413 	},
414 	[ID_AD5640_1250] = {
415 		.channel = AD5446_CHANNEL_POWERDOWN(14, 16, 0),
416 		.int_vref_mv = 1250,
417 		.write = ad5446_write,
418 	},
419 	[ID_AD5660_2500] = {
420 		.channel = AD5446_CHANNEL_POWERDOWN(16, 16, 0),
421 		.int_vref_mv = 2500,
422 		.write = ad5660_write,
423 	},
424 	[ID_AD5660_1250] = {
425 		.channel = AD5446_CHANNEL_POWERDOWN(16, 16, 0),
426 		.int_vref_mv = 1250,
427 		.write = ad5660_write,
428 	},
429 	[ID_AD5662] = {
430 		.channel = AD5446_CHANNEL_POWERDOWN(16, 16, 0),
431 		.write = ad5660_write,
432 	},
433 };
434 
435 static const struct spi_device_id ad5446_spi_ids[] = {
436 	{"ad5300", ID_AD5300},
437 	{"ad5310", ID_AD5310},
438 	{"ad5320", ID_AD5320},
439 	{"ad5444", ID_AD5444},
440 	{"ad5446", ID_AD5446},
441 	{"ad5450", ID_AD5450},
442 	{"ad5451", ID_AD5451},
443 	{"ad5452", ID_AD5444}, /* ad5452 is compatible to the ad5444 */
444 	{"ad5453", ID_AD5446}, /* ad5453 is compatible to the ad5446 */
445 	{"ad5512a", ID_AD5512A},
446 	{"ad5541a", ID_AD5541A},
447 	{"ad5542a", ID_AD5541A}, /* ad5541a and ad5542a are compatible */
448 	{"ad5543", ID_AD5541A}, /* ad5541a and ad5543 are compatible */
449 	{"ad5553", ID_AD5553},
450 	{"ad5601", ID_AD5601},
451 	{"ad5611", ID_AD5611},
452 	{"ad5621", ID_AD5621},
453 	{"ad5620-2500", ID_AD5620_2500}, /* AD5620/40/60: */
454 	{"ad5620-1250", ID_AD5620_1250}, /* part numbers may look differently */
455 	{"ad5640-2500", ID_AD5640_2500},
456 	{"ad5640-1250", ID_AD5640_1250},
457 	{"ad5660-2500", ID_AD5660_2500},
458 	{"ad5660-1250", ID_AD5660_1250},
459 	{"ad5662", ID_AD5662},
460 	{}
461 };
462 MODULE_DEVICE_TABLE(spi, ad5446_spi_ids);
463 
464 static int ad5446_spi_probe(struct spi_device *spi)
465 {
466 	const struct spi_device_id *id = spi_get_device_id(spi);
467 
468 	return ad5446_probe(&spi->dev, id->name,
469 		&ad5446_spi_chip_info[id->driver_data]);
470 }
471 
472 static int ad5446_spi_remove(struct spi_device *spi)
473 {
474 	return ad5446_remove(&spi->dev);
475 }
476 
477 static struct spi_driver ad5446_spi_driver = {
478 	.driver = {
479 		.name	= "ad5446",
480 		.owner	= THIS_MODULE,
481 	},
482 	.probe		= ad5446_spi_probe,
483 	.remove		= ad5446_spi_remove,
484 	.id_table	= ad5446_spi_ids,
485 };
486 
487 static int __init ad5446_spi_register_driver(void)
488 {
489 	return spi_register_driver(&ad5446_spi_driver);
490 }
491 
492 static void ad5446_spi_unregister_driver(void)
493 {
494 	spi_unregister_driver(&ad5446_spi_driver);
495 }
496 
497 #else
498 
499 static inline int ad5446_spi_register_driver(void) { return 0; }
500 static inline void ad5446_spi_unregister_driver(void) { }
501 
502 #endif
503 
504 #if IS_ENABLED(CONFIG_I2C)
505 
506 static int ad5622_write(struct ad5446_state *st, unsigned val)
507 {
508 	struct i2c_client *client = to_i2c_client(st->dev);
509 	__be16 data = cpu_to_be16(val);
510 
511 	return i2c_master_send(client, (char *)&data, sizeof(data));
512 }
513 
514 /**
515  * ad5446_supported_i2c_device_ids:
516  * The AD5620/40/60 parts are available in different fixed internal reference
517  * voltage options. The actual part numbers may look differently
518  * (and a bit cryptic), however this style is used to make clear which
519  * parts are supported here.
520  */
521 enum ad5446_supported_i2c_device_ids {
522 	ID_AD5602,
523 	ID_AD5612,
524 	ID_AD5622,
525 };
526 
527 static const struct ad5446_chip_info ad5446_i2c_chip_info[] = {
528 	[ID_AD5602] = {
529 		.channel = AD5446_CHANNEL_POWERDOWN(8, 16, 4),
530 		.write = ad5622_write,
531 	},
532 	[ID_AD5612] = {
533 		.channel = AD5446_CHANNEL_POWERDOWN(10, 16, 2),
534 		.write = ad5622_write,
535 	},
536 	[ID_AD5622] = {
537 		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 0),
538 		.write = ad5622_write,
539 	},
540 };
541 
542 static int ad5446_i2c_probe(struct i2c_client *i2c,
543 			    const struct i2c_device_id *id)
544 {
545 	return ad5446_probe(&i2c->dev, id->name,
546 		&ad5446_i2c_chip_info[id->driver_data]);
547 }
548 
549 static int ad5446_i2c_remove(struct i2c_client *i2c)
550 {
551 	return ad5446_remove(&i2c->dev);
552 }
553 
554 static const struct i2c_device_id ad5446_i2c_ids[] = {
555 	{"ad5301", ID_AD5602},
556 	{"ad5311", ID_AD5612},
557 	{"ad5321", ID_AD5622},
558 	{"ad5602", ID_AD5602},
559 	{"ad5612", ID_AD5612},
560 	{"ad5622", ID_AD5622},
561 	{}
562 };
563 MODULE_DEVICE_TABLE(i2c, ad5446_i2c_ids);
564 
565 static struct i2c_driver ad5446_i2c_driver = {
566 	.driver = {
567 		   .name = "ad5446",
568 		   .owner = THIS_MODULE,
569 	},
570 	.probe = ad5446_i2c_probe,
571 	.remove = ad5446_i2c_remove,
572 	.id_table = ad5446_i2c_ids,
573 };
574 
575 static int __init ad5446_i2c_register_driver(void)
576 {
577 	return i2c_add_driver(&ad5446_i2c_driver);
578 }
579 
580 static void __exit ad5446_i2c_unregister_driver(void)
581 {
582 	i2c_del_driver(&ad5446_i2c_driver);
583 }
584 
585 #else
586 
587 static inline int ad5446_i2c_register_driver(void) { return 0; }
588 static inline void ad5446_i2c_unregister_driver(void) { }
589 
590 #endif
591 
592 static int __init ad5446_init(void)
593 {
594 	int ret;
595 
596 	ret = ad5446_spi_register_driver();
597 	if (ret)
598 		return ret;
599 
600 	ret = ad5446_i2c_register_driver();
601 	if (ret) {
602 		ad5446_spi_unregister_driver();
603 		return ret;
604 	}
605 
606 	return 0;
607 }
608 module_init(ad5446_init);
609 
610 static void __exit ad5446_exit(void)
611 {
612 	ad5446_i2c_unregister_driver();
613 	ad5446_spi_unregister_driver();
614 }
615 module_exit(ad5446_exit);
616 
617 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
618 MODULE_DESCRIPTION("Analog Devices AD5444/AD5446 DAC");
619 MODULE_LICENSE("GPL v2");
620