1/*
2 * AD5024, AD5025, AD5044, AD5045, AD5064, AD5064-1, AD5065, AD5628, AD5629R,
3 * AD5648, AD5666, AD5668, AD5669R Digital to analog converters driver
4 *
5 * Copyright 2011 Analog Devices Inc.
6 *
7 * Licensed under the GPL-2.
8 */
9
10#include <linux/device.h>
11#include <linux/err.h>
12#include <linux/module.h>
13#include <linux/kernel.h>
14#include <linux/spi/spi.h>
15#include <linux/i2c.h>
16#include <linux/slab.h>
17#include <linux/sysfs.h>
18#include <linux/regulator/consumer.h>
19#include <asm/unaligned.h>
20
21#include <linux/iio/iio.h>
22#include <linux/iio/sysfs.h>
23
24#define AD5064_MAX_DAC_CHANNELS			8
25#define AD5064_MAX_VREFS			4
26
27#define AD5064_ADDR(x)				((x) << 20)
28#define AD5064_CMD(x)				((x) << 24)
29
30#define AD5064_ADDR_ALL_DAC			0xF
31
32#define AD5064_CMD_WRITE_INPUT_N		0x0
33#define AD5064_CMD_UPDATE_DAC_N			0x1
34#define AD5064_CMD_WRITE_INPUT_N_UPDATE_ALL	0x2
35#define AD5064_CMD_WRITE_INPUT_N_UPDATE_N	0x3
36#define AD5064_CMD_POWERDOWN_DAC		0x4
37#define AD5064_CMD_CLEAR			0x5
38#define AD5064_CMD_LDAC_MASK			0x6
39#define AD5064_CMD_RESET			0x7
40#define AD5064_CMD_CONFIG			0x8
41
42#define AD5064_CONFIG_DAISY_CHAIN_ENABLE	BIT(1)
43#define AD5064_CONFIG_INT_VREF_ENABLE		BIT(0)
44
45#define AD5064_LDAC_PWRDN_NONE			0x0
46#define AD5064_LDAC_PWRDN_1K			0x1
47#define AD5064_LDAC_PWRDN_100K			0x2
48#define AD5064_LDAC_PWRDN_3STATE		0x3
49
50/**
51 * struct ad5064_chip_info - chip specific information
52 * @shared_vref:	whether the vref supply is shared between channels
53 * @internal_vref:	internal reference voltage. 0 if the chip has no internal
54 *			vref.
55 * @channel:		channel specification
56 * @num_channels:	number of channels
57 */
58
59struct ad5064_chip_info {
60	bool shared_vref;
61	unsigned long internal_vref;
62	const struct iio_chan_spec *channels;
63	unsigned int num_channels;
64};
65
66struct ad5064_state;
67
68typedef int (*ad5064_write_func)(struct ad5064_state *st, unsigned int cmd,
69		unsigned int addr, unsigned int val);
70
71/**
72 * struct ad5064_state - driver instance specific data
73 * @dev:		the device for this driver instance
74 * @chip_info:		chip model specific constants, available modes etc
75 * @vref_reg:		vref supply regulators
76 * @pwr_down:		whether channel is powered down
77 * @pwr_down_mode:	channel's current power down mode
78 * @dac_cache:		current DAC raw value (chip does not support readback)
79 * @use_internal_vref:	set to true if the internal reference voltage should be
80 *			used.
81 * @write:		register write callback
82 * @data:		i2c/spi transfer buffers
83 */
84
85struct ad5064_state {
86	struct device			*dev;
87	const struct ad5064_chip_info	*chip_info;
88	struct regulator_bulk_data	vref_reg[AD5064_MAX_VREFS];
89	bool				pwr_down[AD5064_MAX_DAC_CHANNELS];
90	u8				pwr_down_mode[AD5064_MAX_DAC_CHANNELS];
91	unsigned int			dac_cache[AD5064_MAX_DAC_CHANNELS];
92	bool				use_internal_vref;
93
94	ad5064_write_func		write;
95
96	/*
97	 * DMA (thus cache coherency maintenance) requires the
98	 * transfer buffers to live in their own cache lines.
99	 */
100	union {
101		u8 i2c[3];
102		__be32 spi;
103	} data ____cacheline_aligned;
104};
105
106enum ad5064_type {
107	ID_AD5024,
108	ID_AD5025,
109	ID_AD5044,
110	ID_AD5045,
111	ID_AD5064,
112	ID_AD5064_1,
113	ID_AD5065,
114	ID_AD5628_1,
115	ID_AD5628_2,
116	ID_AD5648_1,
117	ID_AD5648_2,
118	ID_AD5666_1,
119	ID_AD5666_2,
120	ID_AD5668_1,
121	ID_AD5668_2,
122};
123
124static int ad5064_write(struct ad5064_state *st, unsigned int cmd,
125	unsigned int addr, unsigned int val, unsigned int shift)
126{
127	val <<= shift;
128
129	return st->write(st, cmd, addr, val);
130}
131
132static int ad5064_sync_powerdown_mode(struct ad5064_state *st,
133	const struct iio_chan_spec *chan)
134{
135	unsigned int val;
136	int ret;
137
138	val = (0x1 << chan->address);
139
140	if (st->pwr_down[chan->channel])
141		val |= st->pwr_down_mode[chan->channel] << 8;
142
143	ret = ad5064_write(st, AD5064_CMD_POWERDOWN_DAC, 0, val, 0);
144
145	return ret;
146}
147
148static const char * const ad5064_powerdown_modes[] = {
149	"1kohm_to_gnd",
150	"100kohm_to_gnd",
151	"three_state",
152};
153
154static int ad5064_get_powerdown_mode(struct iio_dev *indio_dev,
155	const struct iio_chan_spec *chan)
156{
157	struct ad5064_state *st = iio_priv(indio_dev);
158
159	return st->pwr_down_mode[chan->channel] - 1;
160}
161
162static int ad5064_set_powerdown_mode(struct iio_dev *indio_dev,
163	const struct iio_chan_spec *chan, unsigned int mode)
164{
165	struct ad5064_state *st = iio_priv(indio_dev);
166	int ret;
167
168	mutex_lock(&indio_dev->mlock);
169	st->pwr_down_mode[chan->channel] = mode + 1;
170
171	ret = ad5064_sync_powerdown_mode(st, chan);
172	mutex_unlock(&indio_dev->mlock);
173
174	return ret;
175}
176
177static const struct iio_enum ad5064_powerdown_mode_enum = {
178	.items = ad5064_powerdown_modes,
179	.num_items = ARRAY_SIZE(ad5064_powerdown_modes),
180	.get = ad5064_get_powerdown_mode,
181	.set = ad5064_set_powerdown_mode,
182};
183
184static ssize_t ad5064_read_dac_powerdown(struct iio_dev *indio_dev,
185	uintptr_t private, const struct iio_chan_spec *chan, char *buf)
186{
187	struct ad5064_state *st = iio_priv(indio_dev);
188
189	return sprintf(buf, "%d\n", st->pwr_down[chan->channel]);
190}
191
192static ssize_t ad5064_write_dac_powerdown(struct iio_dev *indio_dev,
193	 uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
194	 size_t len)
195{
196	struct ad5064_state *st = iio_priv(indio_dev);
197	bool pwr_down;
198	int ret;
199
200	ret = strtobool(buf, &pwr_down);
201	if (ret)
202		return ret;
203
204	mutex_lock(&indio_dev->mlock);
205	st->pwr_down[chan->channel] = pwr_down;
206
207	ret = ad5064_sync_powerdown_mode(st, chan);
208	mutex_unlock(&indio_dev->mlock);
209	return ret ? ret : len;
210}
211
212static int ad5064_get_vref(struct ad5064_state *st,
213	struct iio_chan_spec const *chan)
214{
215	unsigned int i;
216
217	if (st->use_internal_vref)
218		return st->chip_info->internal_vref;
219
220	i = st->chip_info->shared_vref ? 0 : chan->channel;
221	return regulator_get_voltage(st->vref_reg[i].consumer);
222}
223
224static int ad5064_read_raw(struct iio_dev *indio_dev,
225			   struct iio_chan_spec const *chan,
226			   int *val,
227			   int *val2,
228			   long m)
229{
230	struct ad5064_state *st = iio_priv(indio_dev);
231	int scale_uv;
232
233	switch (m) {
234	case IIO_CHAN_INFO_RAW:
235		*val = st->dac_cache[chan->channel];
236		return IIO_VAL_INT;
237	case IIO_CHAN_INFO_SCALE:
238		scale_uv = ad5064_get_vref(st, chan);
239		if (scale_uv < 0)
240			return scale_uv;
241
242		*val = scale_uv / 1000;
243		*val2 = chan->scan_type.realbits;
244		return IIO_VAL_FRACTIONAL_LOG2;
245	default:
246		break;
247	}
248	return -EINVAL;
249}
250
251static int ad5064_write_raw(struct iio_dev *indio_dev,
252	struct iio_chan_spec const *chan, int val, int val2, long mask)
253{
254	struct ad5064_state *st = iio_priv(indio_dev);
255	int ret;
256
257	switch (mask) {
258	case IIO_CHAN_INFO_RAW:
259		if (val >= (1 << chan->scan_type.realbits) || val < 0)
260			return -EINVAL;
261
262		mutex_lock(&indio_dev->mlock);
263		ret = ad5064_write(st, AD5064_CMD_WRITE_INPUT_N_UPDATE_N,
264				chan->address, val, chan->scan_type.shift);
265		if (ret == 0)
266			st->dac_cache[chan->channel] = val;
267		mutex_unlock(&indio_dev->mlock);
268		break;
269	default:
270		ret = -EINVAL;
271	}
272
273	return ret;
274}
275
276static const struct iio_info ad5064_info = {
277	.read_raw = ad5064_read_raw,
278	.write_raw = ad5064_write_raw,
279	.driver_module = THIS_MODULE,
280};
281
282static const struct iio_chan_spec_ext_info ad5064_ext_info[] = {
283	{
284		.name = "powerdown",
285		.read = ad5064_read_dac_powerdown,
286		.write = ad5064_write_dac_powerdown,
287		.shared = IIO_SEPARATE,
288	},
289	IIO_ENUM("powerdown_mode", IIO_SEPARATE, &ad5064_powerdown_mode_enum),
290	IIO_ENUM_AVAILABLE("powerdown_mode", &ad5064_powerdown_mode_enum),
291	{ },
292};
293
294#define AD5064_CHANNEL(chan, addr, bits) {			\
295	.type = IIO_VOLTAGE,					\
296	.indexed = 1,						\
297	.output = 1,						\
298	.channel = (chan),					\
299	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
300	BIT(IIO_CHAN_INFO_SCALE),					\
301	.address = addr,					\
302	.scan_type = {						\
303		.sign = 'u',					\
304		.realbits = (bits),				\
305		.storagebits = 16,				\
306		.shift = 20 - bits,				\
307	},							\
308	.ext_info = ad5064_ext_info,				\
309}
310
311#define DECLARE_AD5064_CHANNELS(name, bits) \
312const struct iio_chan_spec name[] = { \
313	AD5064_CHANNEL(0, 0, bits), \
314	AD5064_CHANNEL(1, 1, bits), \
315	AD5064_CHANNEL(2, 2, bits), \
316	AD5064_CHANNEL(3, 3, bits), \
317	AD5064_CHANNEL(4, 4, bits), \
318	AD5064_CHANNEL(5, 5, bits), \
319	AD5064_CHANNEL(6, 6, bits), \
320	AD5064_CHANNEL(7, 7, bits), \
321}
322
323#define DECLARE_AD5065_CHANNELS(name, bits) \
324const struct iio_chan_spec name[] = { \
325	AD5064_CHANNEL(0, 0, bits), \
326	AD5064_CHANNEL(1, 3, bits), \
327}
328
329static DECLARE_AD5064_CHANNELS(ad5024_channels, 12);
330static DECLARE_AD5064_CHANNELS(ad5044_channels, 14);
331static DECLARE_AD5064_CHANNELS(ad5064_channels, 16);
332
333static DECLARE_AD5065_CHANNELS(ad5025_channels, 12);
334static DECLARE_AD5065_CHANNELS(ad5045_channels, 14);
335static DECLARE_AD5065_CHANNELS(ad5065_channels, 16);
336
337static const struct ad5064_chip_info ad5064_chip_info_tbl[] = {
338	[ID_AD5024] = {
339		.shared_vref = false,
340		.channels = ad5024_channels,
341		.num_channels = 4,
342	},
343	[ID_AD5025] = {
344		.shared_vref = false,
345		.channels = ad5025_channels,
346		.num_channels = 2,
347	},
348	[ID_AD5044] = {
349		.shared_vref = false,
350		.channels = ad5044_channels,
351		.num_channels = 4,
352	},
353	[ID_AD5045] = {
354		.shared_vref = false,
355		.channels = ad5045_channels,
356		.num_channels = 2,
357	},
358	[ID_AD5064] = {
359		.shared_vref = false,
360		.channels = ad5064_channels,
361		.num_channels = 4,
362	},
363	[ID_AD5064_1] = {
364		.shared_vref = true,
365		.channels = ad5064_channels,
366		.num_channels = 4,
367	},
368	[ID_AD5065] = {
369		.shared_vref = false,
370		.channels = ad5065_channels,
371		.num_channels = 2,
372	},
373	[ID_AD5628_1] = {
374		.shared_vref = true,
375		.internal_vref = 2500000,
376		.channels = ad5024_channels,
377		.num_channels = 8,
378	},
379	[ID_AD5628_2] = {
380		.shared_vref = true,
381		.internal_vref = 5000000,
382		.channels = ad5024_channels,
383		.num_channels = 8,
384	},
385	[ID_AD5648_1] = {
386		.shared_vref = true,
387		.internal_vref = 2500000,
388		.channels = ad5044_channels,
389		.num_channels = 8,
390	},
391	[ID_AD5648_2] = {
392		.shared_vref = true,
393		.internal_vref = 5000000,
394		.channels = ad5044_channels,
395		.num_channels = 8,
396	},
397	[ID_AD5666_1] = {
398		.shared_vref = true,
399		.internal_vref = 2500000,
400		.channels = ad5064_channels,
401		.num_channels = 4,
402	},
403	[ID_AD5666_2] = {
404		.shared_vref = true,
405		.internal_vref = 5000000,
406		.channels = ad5064_channels,
407		.num_channels = 4,
408	},
409	[ID_AD5668_1] = {
410		.shared_vref = true,
411		.internal_vref = 2500000,
412		.channels = ad5064_channels,
413		.num_channels = 8,
414	},
415	[ID_AD5668_2] = {
416		.shared_vref = true,
417		.internal_vref = 5000000,
418		.channels = ad5064_channels,
419		.num_channels = 8,
420	},
421};
422
423static inline unsigned int ad5064_num_vref(struct ad5064_state *st)
424{
425	return st->chip_info->shared_vref ? 1 : st->chip_info->num_channels;
426}
427
428static const char * const ad5064_vref_names[] = {
429	"vrefA",
430	"vrefB",
431	"vrefC",
432	"vrefD",
433};
434
435static const char * const ad5064_vref_name(struct ad5064_state *st,
436	unsigned int vref)
437{
438	return st->chip_info->shared_vref ? "vref" : ad5064_vref_names[vref];
439}
440
441static int ad5064_probe(struct device *dev, enum ad5064_type type,
442			const char *name, ad5064_write_func write)
443{
444	struct iio_dev *indio_dev;
445	struct ad5064_state *st;
446	unsigned int midscale;
447	unsigned int i;
448	int ret;
449
450	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
451	if (indio_dev == NULL)
452		return  -ENOMEM;
453
454	st = iio_priv(indio_dev);
455	dev_set_drvdata(dev, indio_dev);
456
457	st->chip_info = &ad5064_chip_info_tbl[type];
458	st->dev = dev;
459	st->write = write;
460
461	for (i = 0; i < ad5064_num_vref(st); ++i)
462		st->vref_reg[i].supply = ad5064_vref_name(st, i);
463
464	ret = devm_regulator_bulk_get(dev, ad5064_num_vref(st),
465		st->vref_reg);
466	if (ret) {
467		if (!st->chip_info->internal_vref)
468			return ret;
469		st->use_internal_vref = true;
470		ret = ad5064_write(st, AD5064_CMD_CONFIG, 0,
471			AD5064_CONFIG_INT_VREF_ENABLE, 0);
472		if (ret) {
473			dev_err(dev, "Failed to enable internal vref: %d\n",
474				ret);
475			return ret;
476		}
477	} else {
478		ret = regulator_bulk_enable(ad5064_num_vref(st), st->vref_reg);
479		if (ret)
480			return ret;
481	}
482
483	indio_dev->dev.parent = dev;
484	indio_dev->name = name;
485	indio_dev->info = &ad5064_info;
486	indio_dev->modes = INDIO_DIRECT_MODE;
487	indio_dev->channels = st->chip_info->channels;
488	indio_dev->num_channels = st->chip_info->num_channels;
489
490	midscale = (1 << indio_dev->channels[0].scan_type.realbits) /  2;
491
492	for (i = 0; i < st->chip_info->num_channels; ++i) {
493		st->pwr_down_mode[i] = AD5064_LDAC_PWRDN_1K;
494		st->dac_cache[i] = midscale;
495	}
496
497	ret = iio_device_register(indio_dev);
498	if (ret)
499		goto error_disable_reg;
500
501	return 0;
502
503error_disable_reg:
504	if (!st->use_internal_vref)
505		regulator_bulk_disable(ad5064_num_vref(st), st->vref_reg);
506
507	return ret;
508}
509
510static int ad5064_remove(struct device *dev)
511{
512	struct iio_dev *indio_dev = dev_get_drvdata(dev);
513	struct ad5064_state *st = iio_priv(indio_dev);
514
515	iio_device_unregister(indio_dev);
516
517	if (!st->use_internal_vref)
518		regulator_bulk_disable(ad5064_num_vref(st), st->vref_reg);
519
520	return 0;
521}
522
523#if IS_ENABLED(CONFIG_SPI_MASTER)
524
525static int ad5064_spi_write(struct ad5064_state *st, unsigned int cmd,
526	unsigned int addr, unsigned int val)
527{
528	struct spi_device *spi = to_spi_device(st->dev);
529
530	st->data.spi = cpu_to_be32(AD5064_CMD(cmd) | AD5064_ADDR(addr) | val);
531	return spi_write(spi, &st->data.spi, sizeof(st->data.spi));
532}
533
534static int ad5064_spi_probe(struct spi_device *spi)
535{
536	const struct spi_device_id *id = spi_get_device_id(spi);
537
538	return ad5064_probe(&spi->dev, id->driver_data, id->name,
539				ad5064_spi_write);
540}
541
542static int ad5064_spi_remove(struct spi_device *spi)
543{
544	return ad5064_remove(&spi->dev);
545}
546
547static const struct spi_device_id ad5064_spi_ids[] = {
548	{"ad5024", ID_AD5024},
549	{"ad5025", ID_AD5025},
550	{"ad5044", ID_AD5044},
551	{"ad5045", ID_AD5045},
552	{"ad5064", ID_AD5064},
553	{"ad5064-1", ID_AD5064_1},
554	{"ad5065", ID_AD5065},
555	{"ad5628-1", ID_AD5628_1},
556	{"ad5628-2", ID_AD5628_2},
557	{"ad5648-1", ID_AD5648_1},
558	{"ad5648-2", ID_AD5648_2},
559	{"ad5666-1", ID_AD5666_1},
560	{"ad5666-2", ID_AD5666_2},
561	{"ad5668-1", ID_AD5668_1},
562	{"ad5668-2", ID_AD5668_2},
563	{"ad5668-3", ID_AD5668_2}, /* similar enough to ad5668-2 */
564	{}
565};
566MODULE_DEVICE_TABLE(spi, ad5064_spi_ids);
567
568static struct spi_driver ad5064_spi_driver = {
569	.driver = {
570		   .name = "ad5064",
571		   .owner = THIS_MODULE,
572	},
573	.probe = ad5064_spi_probe,
574	.remove = ad5064_spi_remove,
575	.id_table = ad5064_spi_ids,
576};
577
578static int __init ad5064_spi_register_driver(void)
579{
580	return spi_register_driver(&ad5064_spi_driver);
581}
582
583static void ad5064_spi_unregister_driver(void)
584{
585	spi_unregister_driver(&ad5064_spi_driver);
586}
587
588#else
589
590static inline int ad5064_spi_register_driver(void) { return 0; }
591static inline void ad5064_spi_unregister_driver(void) { }
592
593#endif
594
595#if IS_ENABLED(CONFIG_I2C)
596
597static int ad5064_i2c_write(struct ad5064_state *st, unsigned int cmd,
598	unsigned int addr, unsigned int val)
599{
600	struct i2c_client *i2c = to_i2c_client(st->dev);
601
602	st->data.i2c[0] = (cmd << 4) | addr;
603	put_unaligned_be16(val, &st->data.i2c[1]);
604	return i2c_master_send(i2c, st->data.i2c, 3);
605}
606
607static int ad5064_i2c_probe(struct i2c_client *i2c,
608	const struct i2c_device_id *id)
609{
610	return ad5064_probe(&i2c->dev, id->driver_data, id->name,
611						ad5064_i2c_write);
612}
613
614static int ad5064_i2c_remove(struct i2c_client *i2c)
615{
616	return ad5064_remove(&i2c->dev);
617}
618
619static const struct i2c_device_id ad5064_i2c_ids[] = {
620	{"ad5629-1", ID_AD5628_1},
621	{"ad5629-2", ID_AD5628_2},
622	{"ad5629-3", ID_AD5628_2}, /* similar enough to ad5629-2 */
623	{"ad5669-1", ID_AD5668_1},
624	{"ad5669-2", ID_AD5668_2},
625	{"ad5669-3", ID_AD5668_2}, /* similar enough to ad5669-2 */
626	{}
627};
628MODULE_DEVICE_TABLE(i2c, ad5064_i2c_ids);
629
630static struct i2c_driver ad5064_i2c_driver = {
631	.driver = {
632		   .name = "ad5064",
633		   .owner = THIS_MODULE,
634	},
635	.probe = ad5064_i2c_probe,
636	.remove = ad5064_i2c_remove,
637	.id_table = ad5064_i2c_ids,
638};
639
640static int __init ad5064_i2c_register_driver(void)
641{
642	return i2c_add_driver(&ad5064_i2c_driver);
643}
644
645static void __exit ad5064_i2c_unregister_driver(void)
646{
647	i2c_del_driver(&ad5064_i2c_driver);
648}
649
650#else
651
652static inline int ad5064_i2c_register_driver(void) { return 0; }
653static inline void ad5064_i2c_unregister_driver(void) { }
654
655#endif
656
657static int __init ad5064_init(void)
658{
659	int ret;
660
661	ret = ad5064_spi_register_driver();
662	if (ret)
663		return ret;
664
665	ret = ad5064_i2c_register_driver();
666	if (ret) {
667		ad5064_spi_unregister_driver();
668		return ret;
669	}
670
671	return 0;
672}
673module_init(ad5064_init);
674
675static void __exit ad5064_exit(void)
676{
677	ad5064_i2c_unregister_driver();
678	ad5064_spi_unregister_driver();
679}
680module_exit(ad5064_exit);
681
682MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
683MODULE_DESCRIPTION("Analog Devices AD5024 and similar multi-channel DACs");
684MODULE_LICENSE("GPL v2");
685