xref: /openbmc/linux/drivers/iio/adc/ad9467.c (revision 94b00cd6)
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 #include <linux/cleanup.h>
8 #include <linux/module.h>
9 #include <linux/mutex.h>
10 #include <linux/device.h>
11 #include <linux/kernel.h>
12 #include <linux/slab.h>
13 #include <linux/spi/spi.h>
14 #include <linux/err.h>
15 #include <linux/delay.h>
16 #include <linux/gpio/consumer.h>
17 #include <linux/of.h>
18 
19 
20 #include <linux/iio/iio.h>
21 #include <linux/iio/sysfs.h>
22 
23 #include <linux/clk.h>
24 
25 #include <linux/iio/adc/adi-axi-adc.h>
26 
27 /*
28  * ADI High-Speed ADC common spi interface registers
29  * See Application-Note AN-877:
30  *   https://www.analog.com/media/en/technical-documentation/application-notes/AN-877.pdf
31  */
32 
33 #define AN877_ADC_REG_CHIP_PORT_CONF		0x00
34 #define AN877_ADC_REG_CHIP_ID			0x01
35 #define AN877_ADC_REG_CHIP_GRADE		0x02
36 #define AN877_ADC_REG_CHAN_INDEX		0x05
37 #define AN877_ADC_REG_TRANSFER			0xFF
38 #define AN877_ADC_REG_MODES			0x08
39 #define AN877_ADC_REG_TEST_IO			0x0D
40 #define AN877_ADC_REG_ADC_INPUT			0x0F
41 #define AN877_ADC_REG_OFFSET			0x10
42 #define AN877_ADC_REG_OUTPUT_MODE		0x14
43 #define AN877_ADC_REG_OUTPUT_ADJUST		0x15
44 #define AN877_ADC_REG_OUTPUT_PHASE		0x16
45 #define AN877_ADC_REG_OUTPUT_DELAY		0x17
46 #define AN877_ADC_REG_VREF			0x18
47 #define AN877_ADC_REG_ANALOG_INPUT		0x2C
48 
49 /* AN877_ADC_REG_TEST_IO */
50 #define AN877_ADC_TESTMODE_OFF			0x0
51 #define AN877_ADC_TESTMODE_MIDSCALE_SHORT	0x1
52 #define AN877_ADC_TESTMODE_POS_FULLSCALE	0x2
53 #define AN877_ADC_TESTMODE_NEG_FULLSCALE	0x3
54 #define AN877_ADC_TESTMODE_ALT_CHECKERBOARD	0x4
55 #define AN877_ADC_TESTMODE_PN23_SEQ		0x5
56 #define AN877_ADC_TESTMODE_PN9_SEQ		0x6
57 #define AN877_ADC_TESTMODE_ONE_ZERO_TOGGLE	0x7
58 #define AN877_ADC_TESTMODE_USER			0x8
59 #define AN877_ADC_TESTMODE_BIT_TOGGLE		0x9
60 #define AN877_ADC_TESTMODE_SYNC			0xA
61 #define AN877_ADC_TESTMODE_ONE_BIT_HIGH		0xB
62 #define AN877_ADC_TESTMODE_MIXED_BIT_FREQUENCY	0xC
63 #define AN877_ADC_TESTMODE_RAMP			0xF
64 
65 /* AN877_ADC_REG_TRANSFER */
66 #define AN877_ADC_TRANSFER_SYNC			0x1
67 
68 /* AN877_ADC_REG_OUTPUT_MODE */
69 #define AN877_ADC_OUTPUT_MODE_OFFSET_BINARY	0x0
70 #define AN877_ADC_OUTPUT_MODE_TWOS_COMPLEMENT	0x1
71 #define AN877_ADC_OUTPUT_MODE_GRAY_CODE		0x2
72 
73 /* AN877_ADC_REG_OUTPUT_PHASE */
74 #define AN877_ADC_OUTPUT_EVEN_ODD_MODE_EN	0x20
75 #define AN877_ADC_INVERT_DCO_CLK		0x80
76 
77 /* AN877_ADC_REG_OUTPUT_DELAY */
78 #define AN877_ADC_DCO_DELAY_ENABLE		0x80
79 
80 /*
81  * Analog Devices AD9265 16-Bit, 125/105/80 MSPS ADC
82  */
83 
84 #define CHIPID_AD9265			0x64
85 #define AD9265_DEF_OUTPUT_MODE		0x40
86 #define AD9265_REG_VREF_MASK		0xC0
87 
88 /*
89  * Analog Devices AD9434 12-Bit, 370/500 MSPS ADC
90  */
91 
92 #define CHIPID_AD9434			0x6A
93 #define AD9434_DEF_OUTPUT_MODE		0x00
94 #define AD9434_REG_VREF_MASK		0xC0
95 
96 /*
97  * Analog Devices AD9467 16-Bit, 200/250 MSPS ADC
98  */
99 
100 #define CHIPID_AD9467			0x50
101 #define AD9467_DEF_OUTPUT_MODE		0x08
102 #define AD9467_REG_VREF_MASK		0x0F
103 
104 enum {
105 	ID_AD9265,
106 	ID_AD9434,
107 	ID_AD9467,
108 };
109 
110 struct ad9467_chip_info {
111 	struct adi_axi_adc_chip_info	axi_adc_info;
112 	unsigned int			default_output_mode;
113 	unsigned int			vref_mask;
114 };
115 
116 #define to_ad9467_chip_info(_info)	\
117 	container_of(_info, struct ad9467_chip_info, axi_adc_info)
118 
119 struct ad9467_state {
120 	struct spi_device		*spi;
121 	struct clk			*clk;
122 	unsigned int			output_mode;
123 	unsigned int                    (*scales)[2];
124 
125 	struct gpio_desc		*pwrdown_gpio;
126 	/* ensure consistent state obtained on multiple related accesses */
127 	struct mutex			lock;
128 };
129 
130 static int ad9467_spi_read(struct spi_device *spi, unsigned int reg)
131 {
132 	unsigned char tbuf[2], rbuf[1];
133 	int ret;
134 
135 	tbuf[0] = 0x80 | (reg >> 8);
136 	tbuf[1] = reg & 0xFF;
137 
138 	ret = spi_write_then_read(spi,
139 				  tbuf, ARRAY_SIZE(tbuf),
140 				  rbuf, ARRAY_SIZE(rbuf));
141 
142 	if (ret < 0)
143 		return ret;
144 
145 	return rbuf[0];
146 }
147 
148 static int ad9467_spi_write(struct spi_device *spi, unsigned int reg,
149 			    unsigned int val)
150 {
151 	unsigned char buf[3];
152 
153 	buf[0] = reg >> 8;
154 	buf[1] = reg & 0xFF;
155 	buf[2] = val;
156 
157 	return spi_write(spi, buf, ARRAY_SIZE(buf));
158 }
159 
160 static int ad9467_reg_access(struct adi_axi_adc_conv *conv, unsigned int reg,
161 			     unsigned int writeval, unsigned int *readval)
162 {
163 	struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
164 	struct spi_device *spi = st->spi;
165 	int ret;
166 
167 	if (readval == NULL) {
168 		guard(mutex)(&st->lock);
169 		ret = ad9467_spi_write(spi, reg, writeval);
170 		if (ret)
171 			return ret;
172 		return ad9467_spi_write(spi, AN877_ADC_REG_TRANSFER,
173 					AN877_ADC_TRANSFER_SYNC);
174 	}
175 
176 	ret = ad9467_spi_read(spi, reg);
177 	if (ret < 0)
178 		return ret;
179 	*readval = ret;
180 
181 	return 0;
182 }
183 
184 static const unsigned int ad9265_scale_table[][2] = {
185 	{1250, 0x00}, {1500, 0x40}, {1750, 0x80}, {2000, 0xC0},
186 };
187 
188 static const unsigned int ad9434_scale_table[][2] = {
189 	{1600, 0x1C}, {1580, 0x1D}, {1550, 0x1E}, {1520, 0x1F}, {1500, 0x00},
190 	{1470, 0x01}, {1440, 0x02}, {1420, 0x03}, {1390, 0x04}, {1360, 0x05},
191 	{1340, 0x06}, {1310, 0x07}, {1280, 0x08}, {1260, 0x09}, {1230, 0x0A},
192 	{1200, 0x0B}, {1180, 0x0C},
193 };
194 
195 static const unsigned int ad9467_scale_table[][2] = {
196 	{2000, 0}, {2100, 6}, {2200, 7},
197 	{2300, 8}, {2400, 9}, {2500, 10},
198 };
199 
200 static void __ad9467_get_scale(struct adi_axi_adc_conv *conv, int index,
201 			       unsigned int *val, unsigned int *val2)
202 {
203 	const struct adi_axi_adc_chip_info *info = conv->chip_info;
204 	const struct iio_chan_spec *chan = &info->channels[0];
205 	unsigned int tmp;
206 
207 	tmp = (info->scale_table[index][0] * 1000000ULL) >>
208 			chan->scan_type.realbits;
209 	*val = tmp / 1000000;
210 	*val2 = tmp % 1000000;
211 }
212 
213 #define AD9467_CHAN(_chan, _si, _bits, _sign)				\
214 {									\
215 	.type = IIO_VOLTAGE,						\
216 	.indexed = 1,							\
217 	.channel = _chan,						\
218 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |		\
219 		BIT(IIO_CHAN_INFO_SAMP_FREQ),				\
220 	.info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_SCALE), \
221 	.scan_index = _si,						\
222 	.scan_type = {							\
223 		.sign = _sign,						\
224 		.realbits = _bits,					\
225 		.storagebits = 16,					\
226 	},								\
227 }
228 
229 static const struct iio_chan_spec ad9434_channels[] = {
230 	AD9467_CHAN(0, 0, 12, 'S'),
231 };
232 
233 static const struct iio_chan_spec ad9467_channels[] = {
234 	AD9467_CHAN(0, 0, 16, 'S'),
235 };
236 
237 static const struct ad9467_chip_info ad9467_chip_tbl[] = {
238 	[ID_AD9265] = {
239 		.axi_adc_info = {
240 			.id = CHIPID_AD9265,
241 			.max_rate = 125000000UL,
242 			.scale_table = ad9265_scale_table,
243 			.num_scales = ARRAY_SIZE(ad9265_scale_table),
244 			.channels = ad9467_channels,
245 			.num_channels = ARRAY_SIZE(ad9467_channels),
246 		},
247 		.default_output_mode = AD9265_DEF_OUTPUT_MODE,
248 		.vref_mask = AD9265_REG_VREF_MASK,
249 	},
250 	[ID_AD9434] = {
251 		.axi_adc_info = {
252 			.id = CHIPID_AD9434,
253 			.max_rate = 500000000UL,
254 			.scale_table = ad9434_scale_table,
255 			.num_scales = ARRAY_SIZE(ad9434_scale_table),
256 			.channels = ad9434_channels,
257 			.num_channels = ARRAY_SIZE(ad9434_channels),
258 		},
259 		.default_output_mode = AD9434_DEF_OUTPUT_MODE,
260 		.vref_mask = AD9434_REG_VREF_MASK,
261 	},
262 	[ID_AD9467] = {
263 		.axi_adc_info = {
264 			.id = CHIPID_AD9467,
265 			.max_rate = 250000000UL,
266 			.scale_table = ad9467_scale_table,
267 			.num_scales = ARRAY_SIZE(ad9467_scale_table),
268 			.channels = ad9467_channels,
269 			.num_channels = ARRAY_SIZE(ad9467_channels),
270 		},
271 		.default_output_mode = AD9467_DEF_OUTPUT_MODE,
272 		.vref_mask = AD9467_REG_VREF_MASK,
273 	},
274 };
275 
276 static int ad9467_get_scale(struct adi_axi_adc_conv *conv, int *val, int *val2)
277 {
278 	const struct adi_axi_adc_chip_info *info = conv->chip_info;
279 	const struct ad9467_chip_info *info1 = to_ad9467_chip_info(info);
280 	struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
281 	unsigned int i, vref_val;
282 	int ret;
283 
284 	ret = ad9467_spi_read(st->spi, AN877_ADC_REG_VREF);
285 	if (ret < 0)
286 		return ret;
287 
288 	vref_val = ret & info1->vref_mask;
289 
290 	for (i = 0; i < info->num_scales; i++) {
291 		if (vref_val == info->scale_table[i][1])
292 			break;
293 	}
294 
295 	if (i == info->num_scales)
296 		return -ERANGE;
297 
298 	__ad9467_get_scale(conv, i, val, val2);
299 
300 	return IIO_VAL_INT_PLUS_MICRO;
301 }
302 
303 static int ad9467_set_scale(struct adi_axi_adc_conv *conv, int val, int val2)
304 {
305 	const struct adi_axi_adc_chip_info *info = conv->chip_info;
306 	struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
307 	unsigned int scale_val[2];
308 	unsigned int i;
309 	int ret;
310 
311 	if (val != 0)
312 		return -EINVAL;
313 
314 	for (i = 0; i < info->num_scales; i++) {
315 		__ad9467_get_scale(conv, i, &scale_val[0], &scale_val[1]);
316 		if (scale_val[0] != val || scale_val[1] != val2)
317 			continue;
318 
319 		guard(mutex)(&st->lock);
320 		ret = ad9467_spi_write(st->spi, AN877_ADC_REG_VREF,
321 				       info->scale_table[i][1]);
322 		if (ret < 0)
323 			return ret;
324 
325 		return ad9467_spi_write(st->spi, AN877_ADC_REG_TRANSFER,
326 					AN877_ADC_TRANSFER_SYNC);
327 	}
328 
329 	return -EINVAL;
330 }
331 
332 static int ad9467_read_raw(struct adi_axi_adc_conv *conv,
333 			   struct iio_chan_spec const *chan,
334 			   int *val, int *val2, long m)
335 {
336 	struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
337 
338 	switch (m) {
339 	case IIO_CHAN_INFO_SCALE:
340 		return ad9467_get_scale(conv, val, val2);
341 	case IIO_CHAN_INFO_SAMP_FREQ:
342 		*val = clk_get_rate(st->clk);
343 
344 		return IIO_VAL_INT;
345 	default:
346 		return -EINVAL;
347 	}
348 }
349 
350 static int ad9467_write_raw(struct adi_axi_adc_conv *conv,
351 			    struct iio_chan_spec const *chan,
352 			    int val, int val2, long mask)
353 {
354 	const struct adi_axi_adc_chip_info *info = conv->chip_info;
355 	struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
356 	long r_clk;
357 
358 	switch (mask) {
359 	case IIO_CHAN_INFO_SCALE:
360 		return ad9467_set_scale(conv, val, val2);
361 	case IIO_CHAN_INFO_SAMP_FREQ:
362 		r_clk = clk_round_rate(st->clk, val);
363 		if (r_clk < 0 || r_clk > info->max_rate) {
364 			dev_warn(&st->spi->dev,
365 				 "Error setting ADC sample rate %ld", r_clk);
366 			return -EINVAL;
367 		}
368 
369 		return clk_set_rate(st->clk, r_clk);
370 	default:
371 		return -EINVAL;
372 	}
373 }
374 
375 static int ad9467_read_avail(struct adi_axi_adc_conv *conv,
376 			     struct iio_chan_spec const *chan,
377 			     const int **vals, int *type, int *length,
378 			     long mask)
379 {
380 	const struct adi_axi_adc_chip_info *info = conv->chip_info;
381 	struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
382 
383 	switch (mask) {
384 	case IIO_CHAN_INFO_SCALE:
385 		*vals = (const int *)st->scales;
386 		*type = IIO_VAL_INT_PLUS_MICRO;
387 		/* Values are stored in a 2D matrix */
388 		*length = info->num_scales * 2;
389 		return IIO_AVAIL_LIST;
390 	default:
391 		return -EINVAL;
392 	}
393 }
394 
395 static int ad9467_outputmode_set(struct spi_device *spi, unsigned int mode)
396 {
397 	int ret;
398 
399 	ret = ad9467_spi_write(spi, AN877_ADC_REG_OUTPUT_MODE, mode);
400 	if (ret < 0)
401 		return ret;
402 
403 	return ad9467_spi_write(spi, AN877_ADC_REG_TRANSFER,
404 				AN877_ADC_TRANSFER_SYNC);
405 }
406 
407 static int ad9467_scale_fill(struct adi_axi_adc_conv *conv)
408 {
409 	const struct adi_axi_adc_chip_info *info = conv->chip_info;
410 	struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
411 	unsigned int i, val1, val2;
412 
413 	st->scales = devm_kmalloc_array(&st->spi->dev, info->num_scales,
414 					sizeof(*st->scales), GFP_KERNEL);
415 	if (!st->scales)
416 		return -ENOMEM;
417 
418 	for (i = 0; i < info->num_scales; i++) {
419 		__ad9467_get_scale(conv, i, &val1, &val2);
420 		st->scales[i][0] = val1;
421 		st->scales[i][1] = val2;
422 	}
423 
424 	return 0;
425 }
426 
427 static int ad9467_preenable_setup(struct adi_axi_adc_conv *conv)
428 {
429 	struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
430 
431 	return ad9467_outputmode_set(st->spi, st->output_mode);
432 }
433 
434 static int ad9467_reset(struct device *dev)
435 {
436 	struct gpio_desc *gpio;
437 
438 	gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
439 	if (IS_ERR_OR_NULL(gpio))
440 		return PTR_ERR_OR_ZERO(gpio);
441 
442 	fsleep(1);
443 	gpiod_set_value_cansleep(gpio, 0);
444 	fsleep(10 * USEC_PER_MSEC);
445 
446 	return 0;
447 }
448 
449 static int ad9467_probe(struct spi_device *spi)
450 {
451 	const struct ad9467_chip_info *info;
452 	struct adi_axi_adc_conv *conv;
453 	struct ad9467_state *st;
454 	unsigned int id;
455 	int ret;
456 
457 	info = of_device_get_match_data(&spi->dev);
458 	if (!info)
459 		info = (void *)spi_get_device_id(spi)->driver_data;
460 	if (!info)
461 		return -ENODEV;
462 
463 	conv = devm_adi_axi_adc_conv_register(&spi->dev, sizeof(*st));
464 	if (IS_ERR(conv))
465 		return PTR_ERR(conv);
466 
467 	st = adi_axi_adc_conv_priv(conv);
468 	st->spi = spi;
469 
470 	st->clk = devm_clk_get_enabled(&spi->dev, "adc-clk");
471 	if (IS_ERR(st->clk))
472 		return PTR_ERR(st->clk);
473 
474 	st->pwrdown_gpio = devm_gpiod_get_optional(&spi->dev, "powerdown",
475 						   GPIOD_OUT_LOW);
476 	if (IS_ERR(st->pwrdown_gpio))
477 		return PTR_ERR(st->pwrdown_gpio);
478 
479 	ret = ad9467_reset(&spi->dev);
480 	if (ret)
481 		return ret;
482 
483 	conv->chip_info = &info->axi_adc_info;
484 
485 	ret = ad9467_scale_fill(conv);
486 	if (ret)
487 		return ret;
488 
489 	id = ad9467_spi_read(spi, AN877_ADC_REG_CHIP_ID);
490 	if (id != conv->chip_info->id) {
491 		dev_err(&spi->dev, "Mismatch CHIP_ID, got 0x%X, expected 0x%X\n",
492 			id, conv->chip_info->id);
493 		return -ENODEV;
494 	}
495 
496 	conv->reg_access = ad9467_reg_access;
497 	conv->write_raw = ad9467_write_raw;
498 	conv->read_raw = ad9467_read_raw;
499 	conv->read_avail = ad9467_read_avail;
500 	conv->preenable_setup = ad9467_preenable_setup;
501 
502 	st->output_mode = info->default_output_mode |
503 			  AN877_ADC_OUTPUT_MODE_TWOS_COMPLEMENT;
504 
505 	return 0;
506 }
507 
508 static const struct of_device_id ad9467_of_match[] = {
509 	{ .compatible = "adi,ad9265", .data = &ad9467_chip_tbl[ID_AD9265], },
510 	{ .compatible = "adi,ad9434", .data = &ad9467_chip_tbl[ID_AD9434], },
511 	{ .compatible = "adi,ad9467", .data = &ad9467_chip_tbl[ID_AD9467], },
512 	{}
513 };
514 MODULE_DEVICE_TABLE(of, ad9467_of_match);
515 
516 static const struct spi_device_id ad9467_ids[] = {
517 	{ "ad9265", (kernel_ulong_t)&ad9467_chip_tbl[ID_AD9265] },
518 	{ "ad9434", (kernel_ulong_t)&ad9467_chip_tbl[ID_AD9434] },
519 	{ "ad9467", (kernel_ulong_t)&ad9467_chip_tbl[ID_AD9467] },
520 	{}
521 };
522 MODULE_DEVICE_TABLE(spi, ad9467_ids);
523 
524 static struct spi_driver ad9467_driver = {
525 	.driver = {
526 		.name = "ad9467",
527 		.of_match_table = ad9467_of_match,
528 	},
529 	.probe = ad9467_probe,
530 	.id_table = ad9467_ids,
531 };
532 module_spi_driver(ad9467_driver);
533 
534 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
535 MODULE_DESCRIPTION("Analog Devices AD9467 ADC driver");
536 MODULE_LICENSE("GPL v2");
537 MODULE_IMPORT_NS(IIO_ADI_AXI);
538