summaryrefslogtreecommitdiff
path: root/drivers/iio/dac/ad5791.c
blob: a4167454da8188a8c5134b2a792aba41b0e3ddf6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
// SPDX-License-Identifier: GPL-2.0-only
/*
 * AD5760, AD5780, AD5781, AD5790, AD5791 Voltage Output Digital to Analog
 * Converter
 *
 * Copyright 2011 Analog Devices Inc.
 */

#include <linux/interrupt.h>
#include <linux/fs.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/spi/spi.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/regulator/consumer.h>
#include <linux/module.h>
#include <linux/bitops.h>

#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/dac/ad5791.h>

#define AD5791_DAC_MASK			GENMASK(19, 0)

#define AD5791_CMD_READ			BIT(23)
#define AD5791_CMD_WRITE		0
#define AD5791_ADDR(addr)		((addr) << 20)

/* Registers */
#define AD5791_ADDR_NOOP		0
#define AD5791_ADDR_DAC0		1
#define AD5791_ADDR_CTRL		2
#define AD5791_ADDR_CLRCODE		3
#define AD5791_ADDR_SW_CTRL		4

/* Control Register */
#define AD5791_CTRL_RBUF		BIT(1)
#define AD5791_CTRL_OPGND		BIT(2)
#define AD5791_CTRL_DACTRI		BIT(3)
#define AD5791_CTRL_BIN2SC		BIT(4)
#define AD5791_CTRL_SDODIS		BIT(5)
#define AD5761_CTRL_LINCOMP(x)		((x) << 6)

#define AD5791_LINCOMP_0_10		0
#define AD5791_LINCOMP_10_12		1
#define AD5791_LINCOMP_12_16		2
#define AD5791_LINCOMP_16_19		3
#define AD5791_LINCOMP_19_20		12

#define AD5780_LINCOMP_0_10		0
#define AD5780_LINCOMP_10_20		12

/* Software Control Register */
#define AD5791_SWCTRL_LDAC		BIT(0)
#define AD5791_SWCTRL_CLR		BIT(1)
#define AD5791_SWCTRL_RESET		BIT(2)

#define AD5791_DAC_PWRDN_6K		0
#define AD5791_DAC_PWRDN_3STATE		1

/**
 * struct ad5791_chip_info - chip specific information
 * @get_lin_comp:	function pointer to the device specific function
 */

struct ad5791_chip_info {
	int (*get_lin_comp)	(unsigned int span);
};

/**
 * struct ad5791_state - driver instance specific data
 * @spi:			spi_device
 * @reg_vdd:		positive supply regulator
 * @reg_vss:		negative supply regulator
 * @chip_info:		chip model specific constants
 * @vref_mv:		actual reference voltage used
 * @vref_neg_mv:	voltage of the negative supply
 * @ctrl:		control register cache
 * @pwr_down_mode:	current power down mode
 * @pwr_down:		true if device is powered down
 * @data:		spi transfer buffers
 */
struct ad5791_state {
	struct spi_device		*spi;
	struct regulator		*reg_vdd;
	struct regulator		*reg_vss;
	const struct ad5791_chip_info	*chip_info;
	unsigned short			vref_mv;
	unsigned int			vref_neg_mv;
	unsigned			ctrl;
	unsigned			pwr_down_mode;
	bool				pwr_down;

	union {
		__be32 d32;
		u8 d8[4];
	} data[3] __aligned(IIO_DMA_MINALIGN);
};

enum ad5791_supported_device_ids {
	ID_AD5760,
	ID_AD5780,
	ID_AD5781,
	ID_AD5791,
};

static int ad5791_spi_write(struct ad5791_state *st, u8 addr, u32 val)
{
	st->data[0].d32 = cpu_to_be32(AD5791_CMD_WRITE |
			      AD5791_ADDR(addr) |
			      (val & AD5791_DAC_MASK));

	return spi_write(st->spi, &st->data[0].d8[1], 3);
}

static int ad5791_spi_read(struct ad5791_state *st, u8 addr, u32 *val)
{
	int ret;
	struct spi_transfer xfers[] = {
		{
			.tx_buf = &st->data[0].d8[1],
			.bits_per_word = 8,
			.len = 3,
			.cs_change = 1,
		}, {
			.tx_buf = &st->data[1].d8[1],
			.rx_buf = &st->data[2].d8[1],
			.bits_per_word = 8,
			.len = 3,
		},
	};

	st->data[0].d32 = cpu_to_be32(AD5791_CMD_READ |
			      AD5791_ADDR(addr));
	st->data[1].d32 = cpu_to_be32(AD5791_ADDR(AD5791_ADDR_NOOP));

	ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers));

	*val = be32_to_cpu(st->data[2].d32);

	return ret;
}

static const char * const ad5791_powerdown_modes[] = {
	"6kohm_to_gnd",
	"three_state",
};

static int ad5791_get_powerdown_mode(struct iio_dev *indio_dev,
	const struct iio_chan_spec *chan)
{
	struct ad5791_state *st = iio_priv(indio_dev);

	return st->pwr_down_mode;
}

static int ad5791_set_powerdown_mode(struct iio_dev *indio_dev,
	const struct iio_chan_spec *chan, unsigned int mode)
{
	struct ad5791_state *st = iio_priv(indio_dev);

	st->pwr_down_mode = mode;

	return 0;
}

static const struct iio_enum ad5791_powerdown_mode_enum = {
	.items = ad5791_powerdown_modes,
	.num_items = ARRAY_SIZE(ad5791_powerdown_modes),
	.get = ad5791_get_powerdown_mode,
	.set = ad5791_set_powerdown_mode,
};

static ssize_t ad5791_read_dac_powerdown(struct iio_dev *indio_dev,
	uintptr_t private, const struct iio_chan_spec *chan, char *buf)
{
	struct ad5791_state *st = iio_priv(indio_dev);

	return sysfs_emit(buf, "%d\n", st->pwr_down);
}

static ssize_t ad5791_write_dac_powerdown(struct iio_dev *indio_dev,
	 uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
	 size_t len)
{
	bool pwr_down;
	int ret;
	struct ad5791_state *st = iio_priv(indio_dev);

	ret = kstrtobool(buf, &pwr_down);
	if (ret)
		return ret;

	if (!pwr_down) {
		st->ctrl &= ~(AD5791_CTRL_OPGND | AD5791_CTRL_DACTRI);
	} else {
		if (st->pwr_down_mode == AD5791_DAC_PWRDN_6K)
			st->ctrl |= AD5791_CTRL_OPGND;
		else if (st->pwr_down_mode == AD5791_DAC_PWRDN_3STATE)
			st->ctrl |= AD5791_CTRL_DACTRI;
	}
	st->pwr_down = pwr_down;

	ret = ad5791_spi_write(st, AD5791_ADDR_CTRL, st->ctrl);

	return ret ? ret : len;
}

static int ad5791_get_lin_comp(unsigned int span)
{
	if (span <= 10000)
		return AD5791_LINCOMP_0_10;
	else if (span <= 12000)
		return AD5791_LINCOMP_10_12;
	else if (span <= 16000)
		return AD5791_LINCOMP_12_16;
	else if (span <= 19000)
		return AD5791_LINCOMP_16_19;
	else
		return AD5791_LINCOMP_19_20;
}

static int ad5780_get_lin_comp(unsigned int span)
{
	if (span <= 10000)
		return AD5780_LINCOMP_0_10;
	else
		return AD5780_LINCOMP_10_20;
}
static const struct ad5791_chip_info ad5791_chip_info_tbl[] = {
	[ID_AD5760] = {
		.get_lin_comp = ad5780_get_lin_comp,
	},
	[ID_AD5780] = {
		.get_lin_comp = ad5780_get_lin_comp,
	},
	[ID_AD5781] = {
		.get_lin_comp = ad5791_get_lin_comp,
	},
	[ID_AD5791] = {
		.get_lin_comp = ad5791_get_lin_comp,
	},
};

static int ad5791_read_raw(struct iio_dev *indio_dev,
			   struct iio_chan_spec const *chan,
			   int *val,
			   int *val2,
			   long m)
{
	struct ad5791_state *st = iio_priv(indio_dev);
	u64 val64;
	int ret;

	switch (m) {
	case IIO_CHAN_INFO_RAW:
		ret = ad5791_spi_read(st, chan->address, val);
		if (ret)
			return ret;
		*val &= AD5791_DAC_MASK;
		*val >>= chan->scan_type.shift;
		return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
		*val = st->vref_mv;
		*val2 = (1 << chan->scan_type.realbits) - 1;
		return IIO_VAL_FRACTIONAL;
	case IIO_CHAN_INFO_OFFSET:
		val64 = (((u64)st->vref_neg_mv) << chan->scan_type.realbits);
		do_div(val64, st->vref_mv);
		*val = -val64;
		return IIO_VAL_INT;
	default:
		return -EINVAL;
	}

};

static const struct iio_chan_spec_ext_info ad5791_ext_info[] = {
	{
		.name = "powerdown",
		.shared = IIO_SHARED_BY_TYPE,
		.read = ad5791_read_dac_powerdown,
		.write = ad5791_write_dac_powerdown,
	},
	IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE,
		 &ad5791_powerdown_mode_enum),
	IIO_ENUM_AVAILABLE("powerdown_mode", IIO_SHARED_BY_TYPE, &ad5791_powerdown_mode_enum),
	{ },
};

#define AD5791_CHAN(bits, _shift) {			\
	.type = IIO_VOLTAGE,				\
	.output = 1,					\
	.indexed = 1,					\
	.address = AD5791_ADDR_DAC0,			\
	.channel = 0,					\
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |	\
		BIT(IIO_CHAN_INFO_OFFSET),		\
	.scan_type = {					\
		.sign = 'u',				\
		.realbits = (bits),			\
		.storagebits = 24,			\
		.shift = (_shift),			\
	},						\
	.ext_info = ad5791_ext_info,			\
}

static const struct iio_chan_spec ad5791_channels[] = {
	[ID_AD5760] = AD5791_CHAN(16, 4),
	[ID_AD5780] = AD5791_CHAN(18, 2),
	[ID_AD5781] = AD5791_CHAN(18, 2),
	[ID_AD5791] = AD5791_CHAN(20, 0)
};

static int ad5791_write_raw(struct iio_dev *indio_dev,
			    struct iio_chan_spec const *chan,
			    int val,
			    int val2,
			    long mask)
{
	struct ad5791_state *st = iio_priv(indio_dev);

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		val &= GENMASK(chan->scan_type.realbits - 1, 0);
		val <<= chan->scan_type.shift;

		return ad5791_spi_write(st, chan->address, val);

	default:
		return -EINVAL;
	}
}

static const struct iio_info ad5791_info = {
	.read_raw = &ad5791_read_raw,
	.write_raw = &ad5791_write_raw,
};

static int ad5791_probe(struct spi_device *spi)
{
	struct ad5791_platform_data *pdata = spi->dev.platform_data;
	struct iio_dev *indio_dev;
	struct ad5791_state *st;
	int ret, pos_voltage_uv = 0, neg_voltage_uv = 0;

	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
	if (!indio_dev)
		return -ENOMEM;
	st = iio_priv(indio_dev);
	st->reg_vdd = devm_regulator_get(&spi->dev, "vdd");
	if (!IS_ERR(st->reg_vdd)) {
		ret = regulator_enable(st->reg_vdd);
		if (ret)
			return ret;

		ret = regulator_get_voltage(st->reg_vdd);
		if (ret < 0)
			goto error_disable_reg_pos;

		pos_voltage_uv = ret;
	}

	st->reg_vss = devm_regulator_get(&spi->dev, "vss");
	if (!IS_ERR(st->reg_vss)) {
		ret = regulator_enable(st->reg_vss);
		if (ret)
			goto error_disable_reg_pos;

		ret = regulator_get_voltage(st->reg_vss);
		if (ret < 0)
			goto error_disable_reg_neg;

		neg_voltage_uv = ret;
	}

	st->pwr_down = true;
	st->spi = spi;

	if (!IS_ERR(st->reg_vss) && !IS_ERR(st->reg_vdd)) {
		st->vref_mv = (pos_voltage_uv + neg_voltage_uv) / 1000;
		st->vref_neg_mv = neg_voltage_uv / 1000;
	} else if (pdata) {
		st->vref_mv = pdata->vref_pos_mv + pdata->vref_neg_mv;
		st->vref_neg_mv = pdata->vref_neg_mv;
	} else {
		dev_warn(&spi->dev, "reference voltage unspecified\n");
	}

	ret = ad5791_spi_write(st, AD5791_ADDR_SW_CTRL, AD5791_SWCTRL_RESET);
	if (ret)
		goto error_disable_reg_neg;

	st->chip_info =	&ad5791_chip_info_tbl[spi_get_device_id(spi)
					      ->driver_data];


	st->ctrl = AD5761_CTRL_LINCOMP(st->chip_info->get_lin_comp(st->vref_mv))
		  | ((pdata && pdata->use_rbuf_gain2) ? 0 : AD5791_CTRL_RBUF) |
		  AD5791_CTRL_BIN2SC;

	ret = ad5791_spi_write(st, AD5791_ADDR_CTRL, st->ctrl |
		AD5791_CTRL_OPGND | AD5791_CTRL_DACTRI);
	if (ret)
		goto error_disable_reg_neg;

	spi_set_drvdata(spi, indio_dev);
	indio_dev->info = &ad5791_info;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels
		= &ad5791_channels[spi_get_device_id(spi)->driver_data];
	indio_dev->num_channels = 1;
	indio_dev->name = spi_get_device_id(st->spi)->name;
	ret = iio_device_register(indio_dev);
	if (ret)
		goto error_disable_reg_neg;

	return 0;

error_disable_reg_neg:
	if (!IS_ERR(st->reg_vss))
		regulator_disable(st->reg_vss);
error_disable_reg_pos:
	if (!IS_ERR(st->reg_vdd))
		regulator_disable(st->reg_vdd);
	return ret;
}

static void ad5791_remove(struct spi_device *spi)
{
	struct iio_dev *indio_dev = spi_get_drvdata(spi);
	struct ad5791_state *st = iio_priv(indio_dev);

	iio_device_unregister(indio_dev);
	if (!IS_ERR(st->reg_vdd))
		regulator_disable(st->reg_vdd);

	if (!IS_ERR(st->reg_vss))
		regulator_disable(st->reg_vss);
}

static const struct spi_device_id ad5791_id[] = {
	{"ad5760", ID_AD5760},
	{"ad5780", ID_AD5780},
	{"ad5781", ID_AD5781},
	{"ad5790", ID_AD5791},
	{"ad5791", ID_AD5791},
	{}
};
MODULE_DEVICE_TABLE(spi, ad5791_id);

static struct spi_driver ad5791_driver = {
	.driver = {
		   .name = "ad5791",
		   },
	.probe = ad5791_probe,
	.remove = ad5791_remove,
	.id_table = ad5791_id,
};
module_spi_driver(ad5791_driver);

MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
MODULE_DESCRIPTION("Analog Devices AD5760/AD5780/AD5781/AD5790/AD5791 DAC");
MODULE_LICENSE("GPL v2");