xref: /kernel/linux/linux-5.10/drivers/iio/adc/ad9467.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Analog Devices AD9467 SPI ADC driver
4 *
5 * Copyright 2012-2020 Analog Devices Inc.
6 */
7
8#include <linux/module.h>
9#include <linux/device.h>
10#include <linux/kernel.h>
11#include <linux/slab.h>
12#include <linux/spi/spi.h>
13#include <linux/err.h>
14#include <linux/delay.h>
15#include <linux/gpio/consumer.h>
16#include <linux/of_device.h>
17
18
19#include <linux/iio/iio.h>
20#include <linux/iio/sysfs.h>
21
22#include <linux/clk.h>
23
24#include <linux/iio/adc/adi-axi-adc.h>
25
26/*
27 * ADI High-Speed ADC common spi interface registers
28 * See Application-Note AN-877:
29 *   https://www.analog.com/media/en/technical-documentation/application-notes/AN-877.pdf
30 */
31
32#define AN877_ADC_REG_CHIP_PORT_CONF		0x00
33#define AN877_ADC_REG_CHIP_ID			0x01
34#define AN877_ADC_REG_CHIP_GRADE		0x02
35#define AN877_ADC_REG_CHAN_INDEX		0x05
36#define AN877_ADC_REG_TRANSFER			0xFF
37#define AN877_ADC_REG_MODES			0x08
38#define AN877_ADC_REG_TEST_IO			0x0D
39#define AN877_ADC_REG_ADC_INPUT			0x0F
40#define AN877_ADC_REG_OFFSET			0x10
41#define AN877_ADC_REG_OUTPUT_MODE		0x14
42#define AN877_ADC_REG_OUTPUT_ADJUST		0x15
43#define AN877_ADC_REG_OUTPUT_PHASE		0x16
44#define AN877_ADC_REG_OUTPUT_DELAY		0x17
45#define AN877_ADC_REG_VREF			0x18
46#define AN877_ADC_REG_ANALOG_INPUT		0x2C
47
48/* AN877_ADC_REG_TEST_IO */
49#define AN877_ADC_TESTMODE_OFF			0x0
50#define AN877_ADC_TESTMODE_MIDSCALE_SHORT	0x1
51#define AN877_ADC_TESTMODE_POS_FULLSCALE	0x2
52#define AN877_ADC_TESTMODE_NEG_FULLSCALE	0x3
53#define AN877_ADC_TESTMODE_ALT_CHECKERBOARD	0x4
54#define AN877_ADC_TESTMODE_PN23_SEQ		0x5
55#define AN877_ADC_TESTMODE_PN9_SEQ		0x6
56#define AN877_ADC_TESTMODE_ONE_ZERO_TOGGLE	0x7
57#define AN877_ADC_TESTMODE_USER			0x8
58#define AN877_ADC_TESTMODE_BIT_TOGGLE		0x9
59#define AN877_ADC_TESTMODE_SYNC			0xA
60#define AN877_ADC_TESTMODE_ONE_BIT_HIGH		0xB
61#define AN877_ADC_TESTMODE_MIXED_BIT_FREQUENCY	0xC
62#define AN877_ADC_TESTMODE_RAMP			0xF
63
64/* AN877_ADC_REG_TRANSFER */
65#define AN877_ADC_TRANSFER_SYNC			0x1
66
67/* AN877_ADC_REG_OUTPUT_MODE */
68#define AN877_ADC_OUTPUT_MODE_OFFSET_BINARY	0x0
69#define AN877_ADC_OUTPUT_MODE_TWOS_COMPLEMENT	0x1
70#define AN877_ADC_OUTPUT_MODE_GRAY_CODE		0x2
71
72/* AN877_ADC_REG_OUTPUT_PHASE */
73#define AN877_ADC_OUTPUT_EVEN_ODD_MODE_EN	0x20
74#define AN877_ADC_INVERT_DCO_CLK		0x80
75
76/* AN877_ADC_REG_OUTPUT_DELAY */
77#define AN877_ADC_DCO_DELAY_ENABLE		0x80
78
79/*
80 * Analog Devices AD9265 16-Bit, 125/105/80 MSPS ADC
81 */
82
83#define CHIPID_AD9265			0x64
84#define AD9265_DEF_OUTPUT_MODE		0x40
85#define AD9265_REG_VREF_MASK		0xC0
86
87/*
88 * Analog Devices AD9434 12-Bit, 370/500 MSPS ADC
89 */
90
91#define CHIPID_AD9434			0x6A
92#define AD9434_DEF_OUTPUT_MODE		0x00
93#define AD9434_REG_VREF_MASK		0xC0
94
95/*
96 * Analog Devices AD9467 16-Bit, 200/250 MSPS ADC
97 */
98
99#define CHIPID_AD9467			0x50
100#define AD9467_DEF_OUTPUT_MODE		0x08
101#define AD9467_REG_VREF_MASK		0x0F
102
103enum {
104	ID_AD9265,
105	ID_AD9434,
106	ID_AD9467,
107};
108
109struct ad9467_chip_info {
110	struct adi_axi_adc_chip_info	axi_adc_info;
111	unsigned int			default_output_mode;
112	unsigned int			vref_mask;
113};
114
115#define to_ad9467_chip_info(_info)	\
116	container_of(_info, struct ad9467_chip_info, axi_adc_info)
117
118struct ad9467_state {
119	struct spi_device		*spi;
120	struct clk			*clk;
121	unsigned int			output_mode;
122	unsigned int                    (*scales)[2];
123
124	struct gpio_desc		*pwrdown_gpio;
125};
126
127static int ad9467_spi_read(struct spi_device *spi, unsigned int reg)
128{
129	unsigned char tbuf[2], rbuf[1];
130	int ret;
131
132	tbuf[0] = 0x80 | (reg >> 8);
133	tbuf[1] = reg & 0xFF;
134
135	ret = spi_write_then_read(spi,
136				  tbuf, ARRAY_SIZE(tbuf),
137				  rbuf, ARRAY_SIZE(rbuf));
138
139	if (ret < 0)
140		return ret;
141
142	return rbuf[0];
143}
144
145static int ad9467_spi_write(struct spi_device *spi, unsigned int reg,
146			    unsigned int val)
147{
148	unsigned char buf[3];
149
150	buf[0] = reg >> 8;
151	buf[1] = reg & 0xFF;
152	buf[2] = val;
153
154	return spi_write(spi, buf, ARRAY_SIZE(buf));
155}
156
157static int ad9467_reg_access(struct adi_axi_adc_conv *conv, unsigned int reg,
158			     unsigned int writeval, unsigned int *readval)
159{
160	struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
161	struct spi_device *spi = st->spi;
162	int ret;
163
164	if (readval == NULL) {
165		ret = ad9467_spi_write(spi, reg, writeval);
166		if (ret)
167			return ret;
168		return ad9467_spi_write(spi, AN877_ADC_REG_TRANSFER,
169					AN877_ADC_TRANSFER_SYNC);
170	}
171
172	ret = ad9467_spi_read(spi, reg);
173	if (ret < 0)
174		return ret;
175	*readval = ret;
176
177	return 0;
178}
179
180static const unsigned int ad9265_scale_table[][2] = {
181	{1250, 0x00}, {1500, 0x40}, {1750, 0x80}, {2000, 0xC0},
182};
183
184static const unsigned int ad9434_scale_table[][2] = {
185	{1600, 0x1C}, {1580, 0x1D}, {1550, 0x1E}, {1520, 0x1F}, {1500, 0x00},
186	{1470, 0x01}, {1440, 0x02}, {1420, 0x03}, {1390, 0x04}, {1360, 0x05},
187	{1340, 0x06}, {1310, 0x07}, {1280, 0x08}, {1260, 0x09}, {1230, 0x0A},
188	{1200, 0x0B}, {1180, 0x0C},
189};
190
191static const unsigned int ad9467_scale_table[][2] = {
192	{2000, 0}, {2100, 6}, {2200, 7},
193	{2300, 8}, {2400, 9}, {2500, 10},
194};
195
196static void __ad9467_get_scale(struct adi_axi_adc_conv *conv, int index,
197			       unsigned int *val, unsigned int *val2)
198{
199	const struct adi_axi_adc_chip_info *info = conv->chip_info;
200	const struct iio_chan_spec *chan = &info->channels[0];
201	unsigned int tmp;
202
203	tmp = (info->scale_table[index][0] * 1000000ULL) >>
204			chan->scan_type.realbits;
205	*val = tmp / 1000000;
206	*val2 = tmp % 1000000;
207}
208
209#define AD9467_CHAN(_chan, _si, _bits, _sign)				\
210{									\
211	.type = IIO_VOLTAGE,						\
212	.indexed = 1,							\
213	.channel = _chan,						\
214	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |		\
215		BIT(IIO_CHAN_INFO_SAMP_FREQ),				\
216	.info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_SCALE), \
217	.scan_index = _si,						\
218	.scan_type = {							\
219		.sign = _sign,						\
220		.realbits = _bits,					\
221		.storagebits = 16,					\
222	},								\
223}
224
225static const struct iio_chan_spec ad9434_channels[] = {
226	AD9467_CHAN(0, 0, 12, 'S'),
227};
228
229static const struct iio_chan_spec ad9467_channels[] = {
230	AD9467_CHAN(0, 0, 16, 'S'),
231};
232
233static const struct ad9467_chip_info ad9467_chip_tbl[] = {
234	[ID_AD9265] = {
235		.axi_adc_info = {
236			.id = CHIPID_AD9265,
237			.max_rate = 125000000UL,
238			.scale_table = ad9265_scale_table,
239			.num_scales = ARRAY_SIZE(ad9265_scale_table),
240			.channels = ad9467_channels,
241			.num_channels = ARRAY_SIZE(ad9467_channels),
242		},
243		.default_output_mode = AD9265_DEF_OUTPUT_MODE,
244		.vref_mask = AD9265_REG_VREF_MASK,
245	},
246	[ID_AD9434] = {
247		.axi_adc_info = {
248			.id = CHIPID_AD9434,
249			.max_rate = 500000000UL,
250			.scale_table = ad9434_scale_table,
251			.num_scales = ARRAY_SIZE(ad9434_scale_table),
252			.channels = ad9434_channels,
253			.num_channels = ARRAY_SIZE(ad9434_channels),
254		},
255		.default_output_mode = AD9434_DEF_OUTPUT_MODE,
256		.vref_mask = AD9434_REG_VREF_MASK,
257	},
258	[ID_AD9467] = {
259		.axi_adc_info = {
260			.id = CHIPID_AD9467,
261			.max_rate = 250000000UL,
262			.scale_table = ad9467_scale_table,
263			.num_scales = ARRAY_SIZE(ad9467_scale_table),
264			.channels = ad9467_channels,
265			.num_channels = ARRAY_SIZE(ad9467_channels),
266		},
267		.default_output_mode = AD9467_DEF_OUTPUT_MODE,
268		.vref_mask = AD9467_REG_VREF_MASK,
269	},
270};
271
272static int ad9467_get_scale(struct adi_axi_adc_conv *conv, int *val, int *val2)
273{
274	const struct adi_axi_adc_chip_info *info = conv->chip_info;
275	const struct ad9467_chip_info *info1 = to_ad9467_chip_info(info);
276	struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
277	unsigned int i, vref_val;
278	int ret;
279
280	ret = ad9467_spi_read(st->spi, AN877_ADC_REG_VREF);
281	if (ret < 0)
282		return ret;
283
284	vref_val = ret & info1->vref_mask;
285
286	for (i = 0; i < info->num_scales; i++) {
287		if (vref_val == info->scale_table[i][1])
288			break;
289	}
290
291	if (i == info->num_scales)
292		return -ERANGE;
293
294	__ad9467_get_scale(conv, i, val, val2);
295
296	return IIO_VAL_INT_PLUS_MICRO;
297}
298
299static int ad9467_set_scale(struct adi_axi_adc_conv *conv, int val, int val2)
300{
301	const struct adi_axi_adc_chip_info *info = conv->chip_info;
302	struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
303	unsigned int scale_val[2];
304	unsigned int i;
305	int ret;
306
307	if (val != 0)
308		return -EINVAL;
309
310	for (i = 0; i < info->num_scales; i++) {
311		__ad9467_get_scale(conv, i, &scale_val[0], &scale_val[1]);
312		if (scale_val[0] != val || scale_val[1] != val2)
313			continue;
314
315		ret = ad9467_spi_write(st->spi, AN877_ADC_REG_VREF,
316				       info->scale_table[i][1]);
317		if (ret < 0)
318			return ret;
319
320		return ad9467_spi_write(st->spi, AN877_ADC_REG_TRANSFER,
321					AN877_ADC_TRANSFER_SYNC);
322	}
323
324	return -EINVAL;
325}
326
327static int ad9467_read_raw(struct adi_axi_adc_conv *conv,
328			   struct iio_chan_spec const *chan,
329			   int *val, int *val2, long m)
330{
331	struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
332
333	switch (m) {
334	case IIO_CHAN_INFO_SCALE:
335		return ad9467_get_scale(conv, val, val2);
336	case IIO_CHAN_INFO_SAMP_FREQ:
337		*val = clk_get_rate(st->clk);
338
339		return IIO_VAL_INT;
340	default:
341		return -EINVAL;
342	}
343}
344
345static int ad9467_write_raw(struct adi_axi_adc_conv *conv,
346			    struct iio_chan_spec const *chan,
347			    int val, int val2, long mask)
348{
349	const struct adi_axi_adc_chip_info *info = conv->chip_info;
350	struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
351	long r_clk;
352
353	switch (mask) {
354	case IIO_CHAN_INFO_SCALE:
355		return ad9467_set_scale(conv, val, val2);
356	case IIO_CHAN_INFO_SAMP_FREQ:
357		r_clk = clk_round_rate(st->clk, val);
358		if (r_clk < 0 || r_clk > info->max_rate) {
359			dev_warn(&st->spi->dev,
360				 "Error setting ADC sample rate %ld", r_clk);
361			return -EINVAL;
362		}
363
364		return clk_set_rate(st->clk, r_clk);
365	default:
366		return -EINVAL;
367	}
368}
369
370static int ad9467_read_avail(struct adi_axi_adc_conv *conv,
371			     struct iio_chan_spec const *chan,
372			     const int **vals, int *type, int *length,
373			     long mask)
374{
375	const struct adi_axi_adc_chip_info *info = conv->chip_info;
376	struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
377
378	switch (mask) {
379	case IIO_CHAN_INFO_SCALE:
380		*vals = (const int *)st->scales;
381		*type = IIO_VAL_INT_PLUS_MICRO;
382		/* Values are stored in a 2D matrix */
383		*length = info->num_scales * 2;
384		return IIO_AVAIL_LIST;
385	default:
386		return -EINVAL;
387	}
388}
389
390static int ad9467_outputmode_set(struct spi_device *spi, unsigned int mode)
391{
392	int ret;
393
394	ret = ad9467_spi_write(spi, AN877_ADC_REG_OUTPUT_MODE, mode);
395	if (ret < 0)
396		return ret;
397
398	return ad9467_spi_write(spi, AN877_ADC_REG_TRANSFER,
399				AN877_ADC_TRANSFER_SYNC);
400}
401
402static int ad9467_scale_fill(struct adi_axi_adc_conv *conv)
403{
404	const struct adi_axi_adc_chip_info *info = conv->chip_info;
405	struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
406	unsigned int i, val1, val2;
407
408	st->scales = devm_kmalloc_array(&st->spi->dev, info->num_scales,
409					sizeof(*st->scales), GFP_KERNEL);
410	if (!st->scales)
411		return -ENOMEM;
412
413	for (i = 0; i < info->num_scales; i++) {
414		__ad9467_get_scale(conv, i, &val1, &val2);
415		st->scales[i][0] = val1;
416		st->scales[i][1] = val2;
417	}
418
419	return 0;
420}
421
422static int ad9467_preenable_setup(struct adi_axi_adc_conv *conv)
423{
424	struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
425
426	return ad9467_outputmode_set(st->spi, st->output_mode);
427}
428
429static int ad9467_reset(struct device *dev)
430{
431	struct gpio_desc *gpio;
432
433	gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
434	if (IS_ERR_OR_NULL(gpio))
435		return PTR_ERR_OR_ZERO(gpio);
436
437	fsleep(1);
438	gpiod_set_value_cansleep(gpio, 0);
439	fsleep(10 * USEC_PER_MSEC);
440
441	return 0;
442}
443
444static int ad9467_probe(struct spi_device *spi)
445{
446	const struct ad9467_chip_info *info;
447	struct adi_axi_adc_conv *conv;
448	struct ad9467_state *st;
449	unsigned int id;
450	int ret;
451
452	info = of_device_get_match_data(&spi->dev);
453	if (!info)
454		return -ENODEV;
455
456	conv = devm_adi_axi_adc_conv_register(&spi->dev, sizeof(*st));
457	if (IS_ERR(conv))
458		return PTR_ERR(conv);
459
460	st = adi_axi_adc_conv_priv(conv);
461	st->spi = spi;
462
463	st->clk = devm_clk_get_enabled(&spi->dev, "adc-clk");
464	if (IS_ERR(st->clk))
465		return PTR_ERR(st->clk);
466
467	st->pwrdown_gpio = devm_gpiod_get_optional(&spi->dev, "powerdown",
468						   GPIOD_OUT_LOW);
469	if (IS_ERR(st->pwrdown_gpio))
470		return PTR_ERR(st->pwrdown_gpio);
471
472	ret = ad9467_reset(&spi->dev);
473	if (ret)
474		return ret;
475
476	spi_set_drvdata(spi, st);
477
478	conv->chip_info = &info->axi_adc_info;
479
480	ret = ad9467_scale_fill(conv);
481	if (ret)
482		return ret;
483
484	id = ad9467_spi_read(spi, AN877_ADC_REG_CHIP_ID);
485	if (id != conv->chip_info->id) {
486		dev_err(&spi->dev, "Mismatch CHIP_ID, got 0x%X, expected 0x%X\n",
487			id, conv->chip_info->id);
488		return -ENODEV;
489	}
490
491	conv->reg_access = ad9467_reg_access;
492	conv->write_raw = ad9467_write_raw;
493	conv->read_raw = ad9467_read_raw;
494	conv->read_avail = ad9467_read_avail;
495	conv->preenable_setup = ad9467_preenable_setup;
496
497	st->output_mode = info->default_output_mode |
498			  AN877_ADC_OUTPUT_MODE_TWOS_COMPLEMENT;
499
500	return 0;
501}
502
503static const struct of_device_id ad9467_of_match[] = {
504	{ .compatible = "adi,ad9265", .data = &ad9467_chip_tbl[ID_AD9265], },
505	{ .compatible = "adi,ad9434", .data = &ad9467_chip_tbl[ID_AD9434], },
506	{ .compatible = "adi,ad9467", .data = &ad9467_chip_tbl[ID_AD9467], },
507	{}
508};
509MODULE_DEVICE_TABLE(of, ad9467_of_match);
510
511static struct spi_driver ad9467_driver = {
512	.driver = {
513		.name = "ad9467",
514		.of_match_table = ad9467_of_match,
515	},
516	.probe = ad9467_probe,
517};
518module_spi_driver(ad9467_driver);
519
520MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
521MODULE_DESCRIPTION("Analog Devices AD9467 ADC driver");
522MODULE_LICENSE("GPL v2");
523