1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Analog Devices AD738x Simultaneous Sampling SAR ADCs
4  *
5  * Copyright 2017 Analog Devices Inc.
6  * Copyright 2024 BayLibre, SAS
7  *
8  * Datasheets of supported parts:
9  * ad7380/1 : https://www.analog.com/media/en/technical-documentation/data-sheets/AD7380-7381.pdf
10  * ad7383/4 : https://www.analog.com/media/en/technical-documentation/data-sheets/ad7383-7384.pdf
11  * ad7386/7/8 : https://www.analog.com/media/en/technical-documentation/data-sheets/AD7386-7387-7388.pdf
12  * ad7380-4 : https://www.analog.com/media/en/technical-documentation/data-sheets/ad7380-4.pdf
13  * ad7381-4 : https://www.analog.com/media/en/technical-documentation/data-sheets/ad7381-4.pdf
14  * ad7383/4-4 : https://www.analog.com/media/en/technical-documentation/data-sheets/ad7383-4-ad7384-4.pdf
15  * ad7386/7/8-4 : https://www.analog.com/media/en/technical-documentation/data-sheets/ad7386-4-7387-4-7388-4.pdf
16  */
17 
18 #include <linux/align.h>
19 #include <linux/bitfield.h>
20 #include <linux/bitops.h>
21 #include <linux/cleanup.h>
22 #include <linux/device.h>
23 #include <linux/err.h>
24 #include <linux/kernel.h>
25 #include <linux/module.h>
26 #include <linux/regmap.h>
27 #include <linux/regulator/consumer.h>
28 #include <linux/slab.h>
29 #include <linux/spi/spi.h>
30 
31 #include <linux/iio/buffer.h>
32 #include <linux/iio/iio.h>
33 #include <linux/iio/trigger_consumer.h>
34 #include <linux/iio/triggered_buffer.h>
35 
36 #define MAX_NUM_CHANNELS		8
37 /* 2.5V internal reference voltage */
38 #define AD7380_INTERNAL_REF_MV		2500
39 
40 /* reading and writing registers is more reliable at lower than max speed */
41 #define AD7380_REG_WR_SPEED_HZ		10000000
42 
43 #define AD7380_REG_WR			BIT(15)
44 #define AD7380_REG_REGADDR		GENMASK(14, 12)
45 #define AD7380_REG_DATA			GENMASK(11, 0)
46 
47 #define AD7380_REG_ADDR_NOP		0x0
48 #define AD7380_REG_ADDR_CONFIG1		0x1
49 #define AD7380_REG_ADDR_CONFIG2		0x2
50 #define AD7380_REG_ADDR_ALERT		0x3
51 #define AD7380_REG_ADDR_ALERT_LOW_TH	0x4
52 #define AD7380_REG_ADDR_ALERT_HIGH_TH	0x5
53 
54 #define AD7380_CONFIG1_CH		BIT(11)
55 #define AD7380_CONFIG1_SEQ		BIT(10)
56 #define AD7380_CONFIG1_OS_MODE		BIT(9)
57 #define AD7380_CONFIG1_OSR		GENMASK(8, 6)
58 #define AD7380_CONFIG1_CRC_W		BIT(5)
59 #define AD7380_CONFIG1_CRC_R		BIT(4)
60 #define AD7380_CONFIG1_ALERTEN		BIT(3)
61 #define AD7380_CONFIG1_RES		BIT(2)
62 #define AD7380_CONFIG1_REFSEL		BIT(1)
63 #define AD7380_CONFIG1_PMODE		BIT(0)
64 
65 #define AD7380_CONFIG2_SDO2		GENMASK(9, 8)
66 #define AD7380_CONFIG2_SDO		BIT(8)
67 #define AD7380_CONFIG2_RESET		GENMASK(7, 0)
68 
69 #define AD7380_CONFIG2_RESET_SOFT	0x3C
70 #define AD7380_CONFIG2_RESET_HARD	0xFF
71 
72 #define AD7380_ALERT_LOW_TH		GENMASK(11, 0)
73 #define AD7380_ALERT_HIGH_TH		GENMASK(11, 0)
74 
75 #define T_CONVERT_NS 190		/* conversion time */
76 #define T_CONVERT_0_NS 10		/* 1st conversion start time (oversampling) */
77 #define T_CONVERT_X_NS 500		/* xth conversion start time (oversampling) */
78 #define T_POWERUP_US 5000		/* Power up */
79 
80 struct ad7380_timing_specs {
81 	const unsigned int t_csh_ns;	/* CS minimum high time */
82 };
83 
84 struct ad7380_chip_info {
85 	const char *name;
86 	const struct iio_chan_spec *channels;
87 	unsigned int num_channels;
88 	unsigned int num_simult_channels;
89 	bool has_mux;
90 	const char * const *supplies;
91 	unsigned int num_supplies;
92 	bool external_ref_only;
93 	const char * const *vcm_supplies;
94 	unsigned int num_vcm_supplies;
95 	const unsigned long *available_scan_masks;
96 	const struct ad7380_timing_specs *timing_specs;
97 };
98 
99 enum {
100 	AD7380_SCAN_TYPE_NORMAL,
101 	AD7380_SCAN_TYPE_RESOLUTION_BOOST,
102 };
103 
104 /* Extended scan types for 12-bit unsigned chips. */
105 static const struct iio_scan_type ad7380_scan_type_12_u[] = {
106 	[AD7380_SCAN_TYPE_NORMAL] = {
107 		.sign = 'u',
108 		.realbits = 12,
109 		.storagebits = 16,
110 		.endianness = IIO_CPU,
111 	},
112 	[AD7380_SCAN_TYPE_RESOLUTION_BOOST] = {
113 		.sign = 'u',
114 		.realbits = 14,
115 		.storagebits = 16,
116 		.endianness = IIO_CPU,
117 	},
118 };
119 
120 /* Extended scan types for 14-bit signed chips. */
121 static const struct iio_scan_type ad7380_scan_type_14_s[] = {
122 	[AD7380_SCAN_TYPE_NORMAL] = {
123 		.sign = 's',
124 		.realbits = 14,
125 		.storagebits = 16,
126 		.endianness = IIO_CPU,
127 	},
128 	[AD7380_SCAN_TYPE_RESOLUTION_BOOST] = {
129 		.sign = 's',
130 		.realbits = 16,
131 		.storagebits = 16,
132 		.endianness = IIO_CPU,
133 	},
134 };
135 
136 /* Extended scan types for 14-bit unsigned chips. */
137 static const struct iio_scan_type ad7380_scan_type_14_u[] = {
138 	[AD7380_SCAN_TYPE_NORMAL] = {
139 		.sign = 'u',
140 		.realbits = 14,
141 		.storagebits = 16,
142 		.endianness = IIO_CPU,
143 	},
144 	[AD7380_SCAN_TYPE_RESOLUTION_BOOST] = {
145 		.sign = 'u',
146 		.realbits = 16,
147 		.storagebits = 16,
148 		.endianness = IIO_CPU,
149 	},
150 };
151 
152 /* Extended scan types for 16-bit signed_chips. */
153 static const struct iio_scan_type ad7380_scan_type_16_s[] = {
154 	[AD7380_SCAN_TYPE_NORMAL] = {
155 		.sign = 's',
156 		.realbits = 16,
157 		.storagebits = 16,
158 		.endianness = IIO_CPU,
159 	},
160 	[AD7380_SCAN_TYPE_RESOLUTION_BOOST] = {
161 		.sign = 's',
162 		.realbits = 18,
163 		.storagebits = 32,
164 		.endianness = IIO_CPU,
165 	},
166 };
167 
168 /* Extended scan types for 16-bit unsigned chips. */
169 static const struct iio_scan_type ad7380_scan_type_16_u[] = {
170 	[AD7380_SCAN_TYPE_NORMAL] = {
171 		.sign = 'u',
172 		.realbits = 16,
173 		.storagebits = 16,
174 		.endianness = IIO_CPU,
175 	},
176 	[AD7380_SCAN_TYPE_RESOLUTION_BOOST] = {
177 		.sign = 'u',
178 		.realbits = 18,
179 		.storagebits = 32,
180 		.endianness = IIO_CPU,
181 	},
182 };
183 
184 #define AD7380_CHANNEL(index, bits, diff, sign) {				\
185 	.type = IIO_VOLTAGE,							\
186 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |				\
187 		((diff) ? 0 : BIT(IIO_CHAN_INFO_OFFSET)),			\
188 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |			\
189 		BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),				\
190 	.info_mask_shared_by_type_available =					\
191 		BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),				\
192 	.indexed = 1,								\
193 	.differential = (diff),							\
194 	.channel = (diff) ? (2 * (index)) : (index),				\
195 	.channel2 = (diff) ? (2 * (index) + 1) : 0,				\
196 	.scan_index = (index),							\
197 	.has_ext_scan_type = 1,							\
198 	.ext_scan_type = ad7380_scan_type_##bits##_##sign,			\
199 	.num_ext_scan_type = ARRAY_SIZE(ad7380_scan_type_##bits##_##sign),	\
200 }
201 
202 #define DEFINE_AD7380_2_CHANNEL(name, bits, diff, sign)	\
203 static const struct iio_chan_spec name[] = {		\
204 	AD7380_CHANNEL(0, bits, diff, sign),		\
205 	AD7380_CHANNEL(1, bits, diff, sign),		\
206 	IIO_CHAN_SOFT_TIMESTAMP(2),			\
207 }
208 
209 #define DEFINE_AD7380_4_CHANNEL(name, bits, diff, sign)	\
210 static const struct iio_chan_spec name[] = {		\
211 	AD7380_CHANNEL(0, bits, diff, sign),		\
212 	AD7380_CHANNEL(1, bits, diff, sign),		\
213 	AD7380_CHANNEL(2, bits, diff, sign),		\
214 	AD7380_CHANNEL(3, bits, diff, sign),		\
215 	IIO_CHAN_SOFT_TIMESTAMP(4),			\
216 }
217 
218 #define DEFINE_AD7380_8_CHANNEL(name, bits, diff, sign)	\
219 static const struct iio_chan_spec name[] = {		\
220 	AD7380_CHANNEL(0, bits, diff, sign),		\
221 	AD7380_CHANNEL(1, bits, diff, sign),		\
222 	AD7380_CHANNEL(2, bits, diff, sign),		\
223 	AD7380_CHANNEL(3, bits, diff, sign),		\
224 	AD7380_CHANNEL(4, bits, diff, sign),		\
225 	AD7380_CHANNEL(5, bits, diff, sign),		\
226 	AD7380_CHANNEL(6, bits, diff, sign),		\
227 	AD7380_CHANNEL(7, bits, diff, sign),		\
228 	IIO_CHAN_SOFT_TIMESTAMP(8),			\
229 }
230 
231 /* fully differential */
232 DEFINE_AD7380_2_CHANNEL(ad7380_channels, 16, 1, s);
233 DEFINE_AD7380_2_CHANNEL(ad7381_channels, 14, 1, s);
234 DEFINE_AD7380_4_CHANNEL(ad7380_4_channels, 16, 1, s);
235 DEFINE_AD7380_4_CHANNEL(ad7381_4_channels, 14, 1, s);
236 /* pseudo differential */
237 DEFINE_AD7380_2_CHANNEL(ad7383_channels, 16, 0, s);
238 DEFINE_AD7380_2_CHANNEL(ad7384_channels, 14, 0, s);
239 DEFINE_AD7380_4_CHANNEL(ad7383_4_channels, 16, 0, s);
240 DEFINE_AD7380_4_CHANNEL(ad7384_4_channels, 14, 0, s);
241 
242 /* Single ended */
243 DEFINE_AD7380_4_CHANNEL(ad7386_channels, 16, 0, u);
244 DEFINE_AD7380_4_CHANNEL(ad7387_channels, 14, 0, u);
245 DEFINE_AD7380_4_CHANNEL(ad7388_channels, 12, 0, u);
246 DEFINE_AD7380_8_CHANNEL(ad7386_4_channels, 16, 0, u);
247 DEFINE_AD7380_8_CHANNEL(ad7387_4_channels, 14, 0, u);
248 DEFINE_AD7380_8_CHANNEL(ad7388_4_channels, 12, 0, u);
249 
250 static const char * const ad7380_supplies[] = {
251 	"vcc", "vlogic",
252 };
253 
254 static const char * const ad7380_2_channel_vcm_supplies[] = {
255 	"aina", "ainb",
256 };
257 
258 static const char * const ad7380_4_channel_vcm_supplies[] = {
259 	"aina", "ainb", "ainc", "aind",
260 };
261 
262 /* Since this is simultaneous sampling, we don't allow individual channels. */
263 static const unsigned long ad7380_2_channel_scan_masks[] = {
264 	GENMASK(1, 0),
265 	0
266 };
267 
268 static const unsigned long ad7380_4_channel_scan_masks[] = {
269 	GENMASK(3, 0),
270 	0
271 };
272 
273 /*
274  * Single ended parts have a 2:1 multiplexer in front of each ADC.
275  *
276  * From an IIO point of view, all inputs are exported, i.e ad7386/7/8
277  * export 4 channels and ad7386-4/7-4/8-4 export 8 channels.
278  *
279  * Inputs AinX0 of multiplexers correspond to the first half of IIO channels
280  * (i.e 0-1 or 0-3) and inputs AinX1 correspond to second half (i.e 2-3 or
281  * 4-7). Example for AD7386/7/8 (2 channels parts):
282  *
283  *           IIO   | AD7386/7/8
284  *                 |         +----------------------------
285  *                 |         |     _____        ______
286  *                 |         |    |     |      |      |
287  *        voltage0 | AinA0 --|--->|     |      |      |
288  *                 |         |    | mux |----->| ADCA |---
289  *        voltage2 | AinA1 --|--->|     |      |      |
290  *                 |         |    |_____|      |_____ |
291  *                 |         |     _____        ______
292  *                 |         |    |     |      |      |
293  *        voltage1 | AinB0 --|--->|     |      |      |
294  *                 |         |    | mux |----->| ADCB |---
295  *        voltage3 | AinB1 --|--->|     |      |      |
296  *                 |         |    |_____|      |______|
297  *                 |         |
298  *                 |         +----------------------------
299  *
300  * Since this is simultaneous sampling for AinX0 OR AinX1 we have two separate
301  * scan masks.
302  * When sequencer mode is enabled, chip automatically cycles through
303  * AinX0 and AinX1 channels. From an IIO point of view, we ca enable all
304  * channels, at the cost of an extra read, thus dividing the maximum rate by
305  * two.
306  */
307 enum {
308 	AD7380_SCAN_MASK_CH_0,
309 	AD7380_SCAN_MASK_CH_1,
310 	AD7380_SCAN_MASK_SEQ,
311 };
312 
313 static const unsigned long ad7380_2x2_channel_scan_masks[] = {
314 	[AD7380_SCAN_MASK_CH_0] = GENMASK(1, 0),
315 	[AD7380_SCAN_MASK_CH_1] = GENMASK(3, 2),
316 	[AD7380_SCAN_MASK_SEQ] = GENMASK(3, 0),
317 	0
318 };
319 
320 static const unsigned long ad7380_2x4_channel_scan_masks[] = {
321 	[AD7380_SCAN_MASK_CH_0] = GENMASK(3, 0),
322 	[AD7380_SCAN_MASK_CH_1] = GENMASK(7, 4),
323 	[AD7380_SCAN_MASK_SEQ] = GENMASK(7, 0),
324 	0
325 };
326 
327 static const struct ad7380_timing_specs ad7380_timing = {
328 	.t_csh_ns = 10,
329 };
330 
331 static const struct ad7380_timing_specs ad7380_4_timing = {
332 	.t_csh_ns = 20,
333 };
334 
335 /*
336  * Available oversampling ratios. The indices correspond with the bit value
337  * expected by the chip.  The available ratios depend on the averaging mode,
338  * only normal averaging is supported for now.
339  */
340 static const int ad7380_oversampling_ratios[] = {
341 	1, 2, 4, 8, 16, 32,
342 };
343 
344 static const struct ad7380_chip_info ad7380_chip_info = {
345 	.name = "ad7380",
346 	.channels = ad7380_channels,
347 	.num_channels = ARRAY_SIZE(ad7380_channels),
348 	.num_simult_channels = 2,
349 	.supplies = ad7380_supplies,
350 	.num_supplies = ARRAY_SIZE(ad7380_supplies),
351 	.available_scan_masks = ad7380_2_channel_scan_masks,
352 	.timing_specs = &ad7380_timing,
353 };
354 
355 static const struct ad7380_chip_info ad7381_chip_info = {
356 	.name = "ad7381",
357 	.channels = ad7381_channels,
358 	.num_channels = ARRAY_SIZE(ad7381_channels),
359 	.num_simult_channels = 2,
360 	.supplies = ad7380_supplies,
361 	.num_supplies = ARRAY_SIZE(ad7380_supplies),
362 	.available_scan_masks = ad7380_2_channel_scan_masks,
363 	.timing_specs = &ad7380_timing,
364 };
365 
366 static const struct ad7380_chip_info ad7383_chip_info = {
367 	.name = "ad7383",
368 	.channels = ad7383_channels,
369 	.num_channels = ARRAY_SIZE(ad7383_channels),
370 	.num_simult_channels = 2,
371 	.supplies = ad7380_supplies,
372 	.num_supplies = ARRAY_SIZE(ad7380_supplies),
373 	.vcm_supplies = ad7380_2_channel_vcm_supplies,
374 	.num_vcm_supplies = ARRAY_SIZE(ad7380_2_channel_vcm_supplies),
375 	.available_scan_masks = ad7380_2_channel_scan_masks,
376 	.timing_specs = &ad7380_timing,
377 };
378 
379 static const struct ad7380_chip_info ad7384_chip_info = {
380 	.name = "ad7384",
381 	.channels = ad7384_channels,
382 	.num_channels = ARRAY_SIZE(ad7384_channels),
383 	.num_simult_channels = 2,
384 	.supplies = ad7380_supplies,
385 	.num_supplies = ARRAY_SIZE(ad7380_supplies),
386 	.vcm_supplies = ad7380_2_channel_vcm_supplies,
387 	.num_vcm_supplies = ARRAY_SIZE(ad7380_2_channel_vcm_supplies),
388 	.available_scan_masks = ad7380_2_channel_scan_masks,
389 	.timing_specs = &ad7380_timing,
390 };
391 
392 static const struct ad7380_chip_info ad7386_chip_info = {
393 	.name = "ad7386",
394 	.channels = ad7386_channels,
395 	.num_channels = ARRAY_SIZE(ad7386_channels),
396 	.num_simult_channels = 2,
397 	.supplies = ad7380_supplies,
398 	.num_supplies = ARRAY_SIZE(ad7380_supplies),
399 	.has_mux = true,
400 	.available_scan_masks = ad7380_2x2_channel_scan_masks,
401 	.timing_specs = &ad7380_timing,
402 };
403 
404 static const struct ad7380_chip_info ad7387_chip_info = {
405 	.name = "ad7387",
406 	.channels = ad7387_channels,
407 	.num_channels = ARRAY_SIZE(ad7387_channels),
408 	.num_simult_channels = 2,
409 	.supplies = ad7380_supplies,
410 	.num_supplies = ARRAY_SIZE(ad7380_supplies),
411 	.has_mux = true,
412 	.available_scan_masks = ad7380_2x2_channel_scan_masks,
413 	.timing_specs = &ad7380_timing,
414 };
415 
416 static const struct ad7380_chip_info ad7388_chip_info = {
417 	.name = "ad7388",
418 	.channels = ad7388_channels,
419 	.num_channels = ARRAY_SIZE(ad7388_channels),
420 	.num_simult_channels = 2,
421 	.supplies = ad7380_supplies,
422 	.num_supplies = ARRAY_SIZE(ad7380_supplies),
423 	.has_mux = true,
424 	.available_scan_masks = ad7380_2x2_channel_scan_masks,
425 	.timing_specs = &ad7380_timing,
426 };
427 
428 static const struct ad7380_chip_info ad7380_4_chip_info = {
429 	.name = "ad7380-4",
430 	.channels = ad7380_4_channels,
431 	.num_channels = ARRAY_SIZE(ad7380_4_channels),
432 	.num_simult_channels = 4,
433 	.supplies = ad7380_supplies,
434 	.num_supplies = ARRAY_SIZE(ad7380_supplies),
435 	.external_ref_only = true,
436 	.available_scan_masks = ad7380_4_channel_scan_masks,
437 	.timing_specs = &ad7380_4_timing,
438 };
439 
440 static const struct ad7380_chip_info ad7381_4_chip_info = {
441 	.name = "ad7381-4",
442 	.channels = ad7381_4_channels,
443 	.num_channels = ARRAY_SIZE(ad7381_4_channels),
444 	.num_simult_channels = 4,
445 	.supplies = ad7380_supplies,
446 	.num_supplies = ARRAY_SIZE(ad7380_supplies),
447 	.available_scan_masks = ad7380_4_channel_scan_masks,
448 	.timing_specs = &ad7380_4_timing,
449 };
450 
451 static const struct ad7380_chip_info ad7383_4_chip_info = {
452 	.name = "ad7383-4",
453 	.channels = ad7383_4_channels,
454 	.num_channels = ARRAY_SIZE(ad7383_4_channels),
455 	.num_simult_channels = 4,
456 	.supplies = ad7380_supplies,
457 	.num_supplies = ARRAY_SIZE(ad7380_supplies),
458 	.vcm_supplies = ad7380_4_channel_vcm_supplies,
459 	.num_vcm_supplies = ARRAY_SIZE(ad7380_4_channel_vcm_supplies),
460 	.available_scan_masks = ad7380_4_channel_scan_masks,
461 	.timing_specs = &ad7380_4_timing,
462 };
463 
464 static const struct ad7380_chip_info ad7384_4_chip_info = {
465 	.name = "ad7384-4",
466 	.channels = ad7384_4_channels,
467 	.num_channels = ARRAY_SIZE(ad7384_4_channels),
468 	.num_simult_channels = 4,
469 	.supplies = ad7380_supplies,
470 	.num_supplies = ARRAY_SIZE(ad7380_supplies),
471 	.vcm_supplies = ad7380_4_channel_vcm_supplies,
472 	.num_vcm_supplies = ARRAY_SIZE(ad7380_4_channel_vcm_supplies),
473 	.available_scan_masks = ad7380_4_channel_scan_masks,
474 	.timing_specs = &ad7380_4_timing,
475 };
476 
477 static const struct ad7380_chip_info ad7386_4_chip_info = {
478 	.name = "ad7386-4",
479 	.channels = ad7386_4_channels,
480 	.num_channels = ARRAY_SIZE(ad7386_4_channels),
481 	.num_simult_channels = 4,
482 	.supplies = ad7380_supplies,
483 	.num_supplies = ARRAY_SIZE(ad7380_supplies),
484 	.has_mux = true,
485 	.available_scan_masks = ad7380_2x4_channel_scan_masks,
486 	.timing_specs = &ad7380_4_timing,
487 };
488 
489 static const struct ad7380_chip_info ad7387_4_chip_info = {
490 	.name = "ad7387-4",
491 	.channels = ad7387_4_channels,
492 	.num_channels = ARRAY_SIZE(ad7387_4_channels),
493 	.num_simult_channels = 4,
494 	.supplies = ad7380_supplies,
495 	.num_supplies = ARRAY_SIZE(ad7380_supplies),
496 	.has_mux = true,
497 	.available_scan_masks = ad7380_2x4_channel_scan_masks,
498 	.timing_specs = &ad7380_4_timing,
499 };
500 
501 static const struct ad7380_chip_info ad7388_4_chip_info = {
502 	.name = "ad7388-4",
503 	.channels = ad7388_4_channels,
504 	.num_channels = ARRAY_SIZE(ad7388_4_channels),
505 	.num_simult_channels = 4,
506 	.supplies = ad7380_supplies,
507 	.num_supplies = ARRAY_SIZE(ad7380_supplies),
508 	.has_mux = true,
509 	.available_scan_masks = ad7380_2x4_channel_scan_masks,
510 	.timing_specs = &ad7380_4_timing,
511 };
512 
513 struct ad7380_state {
514 	const struct ad7380_chip_info *chip_info;
515 	struct spi_device *spi;
516 	struct regmap *regmap;
517 	unsigned int oversampling_ratio;
518 	bool resolution_boost_enabled;
519 	unsigned int ch;
520 	bool seq;
521 	unsigned int vref_mv;
522 	unsigned int vcm_mv[MAX_NUM_CHANNELS];
523 	/* xfers, message an buffer for reading sample data */
524 	struct spi_transfer normal_xfer[2];
525 	struct spi_message normal_msg;
526 	struct spi_transfer seq_xfer[4];
527 	struct spi_message seq_msg;
528 	/*
529 	 * DMA (thus cache coherency maintenance) requires the transfer buffers
530 	 * to live in their own cache lines.
531 	 *
532 	 * Make the buffer large enough for MAX_NUM_CHANNELS 32-bit samples and
533 	 * one 64-bit aligned 64-bit timestamp.
534 	 */
535 	u8 scan_data[ALIGN(MAX_NUM_CHANNELS * sizeof(u32), sizeof(s64))
536 			   + sizeof(s64)] __aligned(IIO_DMA_MINALIGN);
537 	/* buffers for reading/writing registers */
538 	u16 tx;
539 	u16 rx;
540 };
541 
ad7380_regmap_reg_write(void * context,unsigned int reg,unsigned int val)542 static int ad7380_regmap_reg_write(void *context, unsigned int reg,
543 				   unsigned int val)
544 {
545 	struct ad7380_state *st = context;
546 	struct spi_transfer xfer = {
547 		.speed_hz = AD7380_REG_WR_SPEED_HZ,
548 		.bits_per_word = 16,
549 		.len = 2,
550 		.tx_buf = &st->tx,
551 	};
552 
553 	st->tx = FIELD_PREP(AD7380_REG_WR, 1) |
554 		 FIELD_PREP(AD7380_REG_REGADDR, reg) |
555 		 FIELD_PREP(AD7380_REG_DATA, val);
556 
557 	return spi_sync_transfer(st->spi, &xfer, 1);
558 }
559 
ad7380_regmap_reg_read(void * context,unsigned int reg,unsigned int * val)560 static int ad7380_regmap_reg_read(void *context, unsigned int reg,
561 				  unsigned int *val)
562 {
563 	struct ad7380_state *st = context;
564 	struct spi_transfer xfers[] = {
565 		{
566 			.speed_hz = AD7380_REG_WR_SPEED_HZ,
567 			.bits_per_word = 16,
568 			.len = 2,
569 			.tx_buf = &st->tx,
570 			.cs_change = 1,
571 			.cs_change_delay = {
572 				.value = st->chip_info->timing_specs->t_csh_ns,
573 				.unit = SPI_DELAY_UNIT_NSECS,
574 			},
575 		}, {
576 			.speed_hz = AD7380_REG_WR_SPEED_HZ,
577 			.bits_per_word = 16,
578 			.len = 2,
579 			.rx_buf = &st->rx,
580 		},
581 	};
582 	int ret;
583 
584 	st->tx = FIELD_PREP(AD7380_REG_WR, 0) |
585 		 FIELD_PREP(AD7380_REG_REGADDR, reg) |
586 		 FIELD_PREP(AD7380_REG_DATA, 0);
587 
588 	ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers));
589 	if (ret < 0)
590 		return ret;
591 
592 	*val = FIELD_GET(AD7380_REG_DATA, st->rx);
593 
594 	return 0;
595 }
596 
597 static const struct regmap_config ad7380_regmap_config = {
598 	.reg_bits = 3,
599 	.val_bits = 12,
600 	.reg_read = ad7380_regmap_reg_read,
601 	.reg_write = ad7380_regmap_reg_write,
602 	.max_register = AD7380_REG_ADDR_ALERT_HIGH_TH,
603 	.can_sleep = true,
604 };
605 
ad7380_debugfs_reg_access(struct iio_dev * indio_dev,u32 reg,u32 writeval,u32 * readval)606 static int ad7380_debugfs_reg_access(struct iio_dev *indio_dev, u32 reg,
607 				     u32 writeval, u32 *readval)
608 {
609 	iio_device_claim_direct_scoped(return  -EBUSY, indio_dev) {
610 		struct ad7380_state *st = iio_priv(indio_dev);
611 
612 		if (readval)
613 			return regmap_read(st->regmap, reg, readval);
614 		else
615 			return regmap_write(st->regmap, reg, writeval);
616 	}
617 	unreachable();
618 }
619 
620 /*
621  * When switching channel, the ADC require an additional settling time.
622  * According to the datasheet, data is value on the third CS low. We already
623  * have an extra toggle before each read (either direct reads or buffered reads)
624  * to sample correct data, so we just add a single CS toggle at the end of the
625  * register write.
626  */
ad7380_set_ch(struct ad7380_state * st,unsigned int ch)627 static int ad7380_set_ch(struct ad7380_state *st, unsigned int ch)
628 {
629 	struct spi_transfer xfer = {
630 		.delay = {
631 			.value = T_CONVERT_NS,
632 			.unit = SPI_DELAY_UNIT_NSECS,
633 		}
634 	};
635 	int ret;
636 
637 	if (st->ch == ch)
638 		return 0;
639 
640 	ret = regmap_update_bits(st->regmap,
641 				 AD7380_REG_ADDR_CONFIG1,
642 				 AD7380_CONFIG1_CH,
643 				 FIELD_PREP(AD7380_CONFIG1_CH, ch));
644 
645 	if (ret)
646 		return ret;
647 
648 	st->ch = ch;
649 
650 	if (st->oversampling_ratio > 1)
651 		xfer.delay.value = T_CONVERT_0_NS +
652 			T_CONVERT_X_NS * (st->oversampling_ratio - 1);
653 
654 	return spi_sync_transfer(st->spi, &xfer, 1);
655 }
656 
657 /**
658  * ad7380_update_xfers - update the SPI transfers base on the current scan type
659  * @st:		device instance specific state
660  * @scan_type:	current scan type
661  */
ad7380_update_xfers(struct ad7380_state * st,const struct iio_scan_type * scan_type)662 static void ad7380_update_xfers(struct ad7380_state *st,
663 				const struct iio_scan_type *scan_type)
664 {
665 	struct spi_transfer *xfer = st->seq ? st->seq_xfer : st->normal_xfer;
666 	unsigned int t_convert = T_CONVERT_NS;
667 
668 	/*
669 	 * In the case of oversampling, conversion time is higher than in normal
670 	 * mode. Technically T_CONVERT_X_NS is lower for some chips, but we use
671 	 * the maximum value for simplicity for now.
672 	 */
673 	if (st->oversampling_ratio > 1)
674 		t_convert = T_CONVERT_0_NS + T_CONVERT_X_NS *
675 			(st->oversampling_ratio - 1);
676 
677 	if (st->seq) {
678 		xfer[0].delay.value = xfer[1].delay.value = t_convert;
679 		xfer[0].delay.unit = xfer[1].delay.unit = SPI_DELAY_UNIT_NSECS;
680 		xfer[2].bits_per_word = xfer[3].bits_per_word =
681 			scan_type->realbits;
682 		xfer[2].len = xfer[3].len =
683 			BITS_TO_BYTES(scan_type->storagebits) *
684 			st->chip_info->num_simult_channels;
685 		xfer[3].rx_buf = xfer[2].rx_buf + xfer[2].len;
686 		/* Additional delay required here when oversampling is enabled */
687 		if (st->oversampling_ratio > 1)
688 			xfer[2].delay.value = t_convert;
689 		else
690 			xfer[2].delay.value = 0;
691 		xfer[2].delay.unit = SPI_DELAY_UNIT_NSECS;
692 	} else {
693 		xfer[0].delay.value = t_convert;
694 		xfer[0].delay.unit = SPI_DELAY_UNIT_NSECS;
695 		xfer[1].bits_per_word = scan_type->realbits;
696 		xfer[1].len = BITS_TO_BYTES(scan_type->storagebits) *
697 			st->chip_info->num_simult_channels;
698 	}
699 }
700 
ad7380_triggered_buffer_preenable(struct iio_dev * indio_dev)701 static int ad7380_triggered_buffer_preenable(struct iio_dev *indio_dev)
702 {
703 	struct ad7380_state *st = iio_priv(indio_dev);
704 	const struct iio_scan_type *scan_type;
705 	struct spi_message *msg = &st->normal_msg;
706 
707 	/*
708 	 * Currently, we always read all channels at the same time. The scan_type
709 	 * is the same for all channels, so we just pass the first channel.
710 	 */
711 	scan_type = iio_get_current_scan_type(indio_dev, &indio_dev->channels[0]);
712 	if (IS_ERR(scan_type))
713 		return PTR_ERR(scan_type);
714 
715 	if (st->chip_info->has_mux) {
716 		unsigned int index;
717 		int ret;
718 
719 		/*
720 		 * Depending on the requested scan_mask and current state,
721 		 * we need to either change CH bit, or enable sequencer mode
722 		 * to sample correct data.
723 		 * Sequencer mode is enabled if active mask corresponds to all
724 		 * IIO channels enabled. Otherwise, CH bit is set.
725 		 */
726 		ret = iio_active_scan_mask_index(indio_dev);
727 		if (ret < 0)
728 			return ret;
729 
730 		index = ret;
731 		if (index == AD7380_SCAN_MASK_SEQ) {
732 			ret = regmap_update_bits(st->regmap,
733 						 AD7380_REG_ADDR_CONFIG1,
734 						 AD7380_CONFIG1_SEQ,
735 						 FIELD_PREP(AD7380_CONFIG1_SEQ, 1));
736 			if (ret)
737 				return ret;
738 			msg = &st->seq_msg;
739 			st->seq = true;
740 		} else {
741 			ret = ad7380_set_ch(st, index);
742 			if (ret)
743 				return ret;
744 		}
745 
746 	}
747 
748 	ad7380_update_xfers(st, scan_type);
749 
750 	return spi_optimize_message(st->spi, msg);
751 }
752 
ad7380_triggered_buffer_postdisable(struct iio_dev * indio_dev)753 static int ad7380_triggered_buffer_postdisable(struct iio_dev *indio_dev)
754 {
755 	struct ad7380_state *st = iio_priv(indio_dev);
756 	struct spi_message *msg = &st->normal_msg;
757 	int ret;
758 
759 	if (st->seq) {
760 		ret = regmap_update_bits(st->regmap,
761 					 AD7380_REG_ADDR_CONFIG1,
762 					 AD7380_CONFIG1_SEQ,
763 					 FIELD_PREP(AD7380_CONFIG1_SEQ, 0));
764 		if (ret)
765 			return ret;
766 
767 		msg = &st->seq_msg;
768 		st->seq = false;
769 	}
770 
771 	spi_unoptimize_message(msg);
772 
773 	return 0;
774 }
775 
776 static const struct iio_buffer_setup_ops ad7380_buffer_setup_ops = {
777 	.preenable = ad7380_triggered_buffer_preenable,
778 	.postdisable = ad7380_triggered_buffer_postdisable,
779 };
780 
ad7380_trigger_handler(int irq,void * p)781 static irqreturn_t ad7380_trigger_handler(int irq, void *p)
782 {
783 	struct iio_poll_func *pf = p;
784 	struct iio_dev *indio_dev = pf->indio_dev;
785 	struct ad7380_state *st = iio_priv(indio_dev);
786 	struct spi_message *msg = st->seq ? &st->seq_msg : &st->normal_msg;
787 	int ret;
788 
789 	ret = spi_sync(st->spi, msg);
790 	if (ret)
791 		goto out;
792 
793 	iio_push_to_buffers_with_timestamp(indio_dev, &st->scan_data,
794 					   pf->timestamp);
795 
796 out:
797 	iio_trigger_notify_done(indio_dev->trig);
798 
799 	return IRQ_HANDLED;
800 }
801 
ad7380_read_direct(struct ad7380_state * st,unsigned int scan_index,const struct iio_scan_type * scan_type,int * val)802 static int ad7380_read_direct(struct ad7380_state *st, unsigned int scan_index,
803 			      const struct iio_scan_type *scan_type, int *val)
804 {
805 	unsigned int index = scan_index;
806 	int ret;
807 
808 	if (st->chip_info->has_mux) {
809 		unsigned int ch = 0;
810 
811 		if (index >= st->chip_info->num_simult_channels) {
812 			index -= st->chip_info->num_simult_channels;
813 			ch = 1;
814 		}
815 
816 		ret = ad7380_set_ch(st, ch);
817 		if (ret)
818 			return ret;
819 	}
820 
821 	ad7380_update_xfers(st, scan_type);
822 
823 	ret = spi_sync(st->spi, &st->normal_msg);
824 	if (ret < 0)
825 		return ret;
826 
827 	if (scan_type->storagebits > 16) {
828 		if (scan_type->sign == 's')
829 			*val = sign_extend32(*(u32 *)(st->scan_data + 4 * index),
830 					     scan_type->realbits - 1);
831 		else
832 			*val = *(u32 *)(st->scan_data + 4 * index) &
833 				GENMASK(scan_type->realbits - 1, 0);
834 	} else {
835 		if (scan_type->sign == 's')
836 			*val = sign_extend32(*(u16 *)(st->scan_data + 2 * index),
837 					     scan_type->realbits - 1);
838 		else
839 			*val = *(u16 *)(st->scan_data + 2 * index) &
840 				GENMASK(scan_type->realbits - 1, 0);
841 	}
842 
843 	return IIO_VAL_INT;
844 }
845 
ad7380_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long info)846 static int ad7380_read_raw(struct iio_dev *indio_dev,
847 			   struct iio_chan_spec const *chan,
848 			   int *val, int *val2, long info)
849 {
850 	struct ad7380_state *st = iio_priv(indio_dev);
851 	const struct iio_scan_type *scan_type;
852 
853 	scan_type = iio_get_current_scan_type(indio_dev, chan);
854 
855 	if (IS_ERR(scan_type))
856 		return PTR_ERR(scan_type);
857 
858 	switch (info) {
859 	case IIO_CHAN_INFO_RAW:
860 		iio_device_claim_direct_scoped(return -EBUSY, indio_dev) {
861 			return ad7380_read_direct(st, chan->scan_index,
862 						  scan_type, val);
863 		}
864 		unreachable();
865 	case IIO_CHAN_INFO_SCALE:
866 		/*
867 		 * According to the datasheet, the LSB size is:
868 		 *    * (2 × VREF) / 2^N, for differential chips
869 		 *    * VREF / 2^N, for pseudo-differential chips
870 		 * where N is the ADC resolution (i.e realbits)
871 		 */
872 		*val = st->vref_mv;
873 		*val2 = scan_type->realbits - chan->differential;
874 
875 		return IIO_VAL_FRACTIONAL_LOG2;
876 	case IIO_CHAN_INFO_OFFSET:
877 		/*
878 		 * According to IIO ABI, offset is applied before scale,
879 		 * so offset is: vcm_mv / scale
880 		 */
881 		*val = st->vcm_mv[chan->channel] * (1 << scan_type->realbits)
882 			/ st->vref_mv;
883 
884 		return IIO_VAL_INT;
885 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
886 		*val = st->oversampling_ratio;
887 
888 		return IIO_VAL_INT;
889 	default:
890 		return -EINVAL;
891 	}
892 }
893 
ad7380_read_avail(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,const int ** vals,int * type,int * length,long mask)894 static int ad7380_read_avail(struct iio_dev *indio_dev,
895 			     struct iio_chan_spec const *chan,
896 			     const int **vals, int *type, int *length,
897 			     long mask)
898 {
899 	switch (mask) {
900 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
901 		*vals = ad7380_oversampling_ratios;
902 		*length = ARRAY_SIZE(ad7380_oversampling_ratios);
903 		*type = IIO_VAL_INT;
904 
905 		return IIO_AVAIL_LIST;
906 	default:
907 		return -EINVAL;
908 	}
909 }
910 
911 /**
912  * ad7380_osr_to_regval - convert ratio to OSR register value
913  * @ratio: ratio to check
914  *
915  * Check if ratio is present in the list of available ratios and return the
916  * corresponding value that needs to be written to the register to select that
917  * ratio.
918  *
919  * Returns: register value (0 to 7) or -EINVAL if there is not an exact match
920  */
ad7380_osr_to_regval(int ratio)921 static int ad7380_osr_to_regval(int ratio)
922 {
923 	int i;
924 
925 	for (i = 0; i < ARRAY_SIZE(ad7380_oversampling_ratios); i++) {
926 		if (ratio == ad7380_oversampling_ratios[i])
927 			return i;
928 	}
929 
930 	return -EINVAL;
931 }
932 
ad7380_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)933 static int ad7380_write_raw(struct iio_dev *indio_dev,
934 			    struct iio_chan_spec const *chan, int val,
935 			    int val2, long mask)
936 {
937 	struct ad7380_state *st = iio_priv(indio_dev);
938 	int ret, osr, boost;
939 
940 	switch (mask) {
941 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
942 		osr = ad7380_osr_to_regval(val);
943 		if (osr < 0)
944 			return osr;
945 
946 		/* always enable resolution boost when oversampling is enabled */
947 		boost = osr > 0 ? 1 : 0;
948 
949 		iio_device_claim_direct_scoped(return -EBUSY, indio_dev) {
950 			ret = regmap_update_bits(st->regmap,
951 					AD7380_REG_ADDR_CONFIG1,
952 					AD7380_CONFIG1_OSR | AD7380_CONFIG1_RES,
953 					FIELD_PREP(AD7380_CONFIG1_OSR, osr) |
954 					FIELD_PREP(AD7380_CONFIG1_RES, boost));
955 
956 			if (ret)
957 				return ret;
958 
959 			st->oversampling_ratio = val;
960 			st->resolution_boost_enabled = boost;
961 
962 			/*
963 			 * Perform a soft reset. This will flush the oversampling
964 			 * block and FIFO but will maintain the content of the
965 			 * configurable registers.
966 			 */
967 			return regmap_update_bits(st->regmap,
968 					AD7380_REG_ADDR_CONFIG2,
969 					AD7380_CONFIG2_RESET,
970 					FIELD_PREP(AD7380_CONFIG2_RESET,
971 						   AD7380_CONFIG2_RESET_SOFT));
972 		}
973 		unreachable();
974 	default:
975 		return -EINVAL;
976 	}
977 }
978 
ad7380_get_current_scan_type(const struct iio_dev * indio_dev,const struct iio_chan_spec * chan)979 static int ad7380_get_current_scan_type(const struct iio_dev *indio_dev,
980 					const struct iio_chan_spec *chan)
981 {
982 	struct ad7380_state *st = iio_priv(indio_dev);
983 
984 	return st->resolution_boost_enabled ? AD7380_SCAN_TYPE_RESOLUTION_BOOST
985 					    : AD7380_SCAN_TYPE_NORMAL;
986 }
987 
988 static const struct iio_info ad7380_info = {
989 	.read_raw = &ad7380_read_raw,
990 	.read_avail = &ad7380_read_avail,
991 	.write_raw = &ad7380_write_raw,
992 	.get_current_scan_type = &ad7380_get_current_scan_type,
993 	.debugfs_reg_access = &ad7380_debugfs_reg_access,
994 };
995 
ad7380_init(struct ad7380_state * st,bool external_ref_en)996 static int ad7380_init(struct ad7380_state *st, bool external_ref_en)
997 {
998 	int ret;
999 
1000 	/* perform hard reset */
1001 	ret = regmap_update_bits(st->regmap, AD7380_REG_ADDR_CONFIG2,
1002 				 AD7380_CONFIG2_RESET,
1003 				 FIELD_PREP(AD7380_CONFIG2_RESET,
1004 					    AD7380_CONFIG2_RESET_HARD));
1005 	if (ret < 0)
1006 		return ret;
1007 
1008 	if (external_ref_en) {
1009 		/* select external reference voltage */
1010 		ret = regmap_set_bits(st->regmap, AD7380_REG_ADDR_CONFIG1,
1011 				      AD7380_CONFIG1_REFSEL);
1012 		if (ret < 0)
1013 			return ret;
1014 	}
1015 
1016 	/* This is the default value after reset. */
1017 	st->oversampling_ratio = 1;
1018 	st->ch = 0;
1019 	st->seq = false;
1020 
1021 	/* SPI 1-wire mode */
1022 	return regmap_update_bits(st->regmap, AD7380_REG_ADDR_CONFIG2,
1023 				  AD7380_CONFIG2_SDO,
1024 				  FIELD_PREP(AD7380_CONFIG2_SDO, 1));
1025 }
1026 
ad7380_probe(struct spi_device * spi)1027 static int ad7380_probe(struct spi_device *spi)
1028 {
1029 	struct iio_dev *indio_dev;
1030 	struct ad7380_state *st;
1031 	bool external_ref_en;
1032 	int ret, i;
1033 
1034 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
1035 	if (!indio_dev)
1036 		return -ENOMEM;
1037 
1038 	st = iio_priv(indio_dev);
1039 	st->spi = spi;
1040 	st->chip_info = spi_get_device_match_data(spi);
1041 	if (!st->chip_info)
1042 		return dev_err_probe(&spi->dev, -EINVAL, "missing match data\n");
1043 
1044 	ret = devm_regulator_bulk_get_enable(&spi->dev, st->chip_info->num_supplies,
1045 					     st->chip_info->supplies);
1046 
1047 	if (ret)
1048 		return dev_err_probe(&spi->dev, ret,
1049 				     "Failed to enable power supplies\n");
1050 	fsleep(T_POWERUP_US);
1051 
1052 	if (st->chip_info->external_ref_only) {
1053 		ret = devm_regulator_get_enable_read_voltage(&spi->dev,
1054 							     "refin");
1055 		if (ret < 0)
1056 			return dev_err_probe(&spi->dev, ret,
1057 					     "Failed to get refin regulator\n");
1058 
1059 		st->vref_mv = ret / 1000;
1060 
1061 		/* these chips don't have a register bit for this */
1062 		external_ref_en = false;
1063 	} else {
1064 		/*
1065 		 * If there is no REFIO supply, then it means that we are using
1066 		 * the internal reference, otherwise REFIO is reference voltage.
1067 		 */
1068 		ret = devm_regulator_get_enable_read_voltage(&spi->dev,
1069 							     "refio");
1070 		if (ret < 0 && ret != -ENODEV)
1071 			return dev_err_probe(&spi->dev, ret,
1072 					     "Failed to get refio regulator\n");
1073 
1074 		external_ref_en = ret != -ENODEV;
1075 		st->vref_mv = external_ref_en ? ret / 1000 : AD7380_INTERNAL_REF_MV;
1076 	}
1077 
1078 	if (st->chip_info->num_vcm_supplies > ARRAY_SIZE(st->vcm_mv))
1079 		return dev_err_probe(&spi->dev, -EINVAL,
1080 				     "invalid number of VCM supplies\n");
1081 
1082 	/*
1083 	 * pseudo-differential chips have common mode supplies for the negative
1084 	 * input pin.
1085 	 */
1086 	for (i = 0; i < st->chip_info->num_vcm_supplies; i++) {
1087 		const char *vcm = st->chip_info->vcm_supplies[i];
1088 
1089 		ret = devm_regulator_get_enable_read_voltage(&spi->dev, vcm);
1090 		if (ret < 0)
1091 			return dev_err_probe(&spi->dev, ret,
1092 					     "Failed to get %s regulator\n",
1093 					     vcm);
1094 
1095 		st->vcm_mv[i] = ret / 1000;
1096 	}
1097 
1098 	st->regmap = devm_regmap_init(&spi->dev, NULL, st, &ad7380_regmap_config);
1099 	if (IS_ERR(st->regmap))
1100 		return dev_err_probe(&spi->dev, PTR_ERR(st->regmap),
1101 				     "failed to allocate register map\n");
1102 
1103 	/*
1104 	 * Setting up xfer structures for both normal and sequence mode. These
1105 	 * struct are used for both direct read and triggered buffer. Additional
1106 	 * fields will be set up in ad7380_update_xfers() based on the current
1107 	 * state of the driver at the time of the read.
1108 	 */
1109 
1110 	/*
1111 	 * In normal mode a read is composed of two steps:
1112 	 *   - first, toggle CS (no data xfer) to trigger a conversion
1113 	 *   - then, read data
1114 	 */
1115 	st->normal_xfer[0].cs_change = 1;
1116 	st->normal_xfer[0].cs_change_delay.value = st->chip_info->timing_specs->t_csh_ns;
1117 	st->normal_xfer[0].cs_change_delay.unit = SPI_DELAY_UNIT_NSECS;
1118 	st->normal_xfer[1].rx_buf = st->scan_data;
1119 
1120 	spi_message_init_with_transfers(&st->normal_msg, st->normal_xfer,
1121 					ARRAY_SIZE(st->normal_xfer));
1122 	/*
1123 	 * In sequencer mode a read is composed of four steps:
1124 	 *   - CS toggle (no data xfer) to get the right point in the sequence
1125 	 *   - CS toggle (no data xfer) to trigger a conversion of AinX0 and
1126 	 *   acquisition of AinX1
1127 	 *   - 2 data reads, to read AinX0 and AinX1
1128 	 */
1129 	st->seq_xfer[0].cs_change = 1;
1130 	st->seq_xfer[0].cs_change_delay.value = st->chip_info->timing_specs->t_csh_ns;
1131 	st->seq_xfer[0].cs_change_delay.unit = SPI_DELAY_UNIT_NSECS;
1132 	st->seq_xfer[1].cs_change = 1;
1133 	st->seq_xfer[1].cs_change_delay.value = st->chip_info->timing_specs->t_csh_ns;
1134 	st->seq_xfer[1].cs_change_delay.unit = SPI_DELAY_UNIT_NSECS;
1135 
1136 	st->seq_xfer[2].rx_buf = st->scan_data;
1137 	st->seq_xfer[2].cs_change = 1;
1138 	st->seq_xfer[2].cs_change_delay.value = st->chip_info->timing_specs->t_csh_ns;
1139 	st->seq_xfer[2].cs_change_delay.unit = SPI_DELAY_UNIT_NSECS;
1140 
1141 	spi_message_init_with_transfers(&st->seq_msg, st->seq_xfer,
1142 					ARRAY_SIZE(st->seq_xfer));
1143 
1144 	indio_dev->channels = st->chip_info->channels;
1145 	indio_dev->num_channels = st->chip_info->num_channels;
1146 	indio_dev->name = st->chip_info->name;
1147 	indio_dev->info = &ad7380_info;
1148 	indio_dev->modes = INDIO_DIRECT_MODE;
1149 	indio_dev->available_scan_masks = st->chip_info->available_scan_masks;
1150 
1151 	ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
1152 					      iio_pollfunc_store_time,
1153 					      ad7380_trigger_handler,
1154 					      &ad7380_buffer_setup_ops);
1155 	if (ret)
1156 		return ret;
1157 
1158 	ret = ad7380_init(st, external_ref_en);
1159 	if (ret)
1160 		return ret;
1161 
1162 	return devm_iio_device_register(&spi->dev, indio_dev);
1163 }
1164 
1165 static const struct of_device_id ad7380_of_match_table[] = {
1166 	{ .compatible = "adi,ad7380", .data = &ad7380_chip_info },
1167 	{ .compatible = "adi,ad7381", .data = &ad7381_chip_info },
1168 	{ .compatible = "adi,ad7383", .data = &ad7383_chip_info },
1169 	{ .compatible = "adi,ad7384", .data = &ad7384_chip_info },
1170 	{ .compatible = "adi,ad7386", .data = &ad7386_chip_info },
1171 	{ .compatible = "adi,ad7387", .data = &ad7387_chip_info },
1172 	{ .compatible = "adi,ad7388", .data = &ad7388_chip_info },
1173 	{ .compatible = "adi,ad7380-4", .data = &ad7380_4_chip_info },
1174 	{ .compatible = "adi,ad7381-4", .data = &ad7381_4_chip_info },
1175 	{ .compatible = "adi,ad7383-4", .data = &ad7383_4_chip_info },
1176 	{ .compatible = "adi,ad7384-4", .data = &ad7384_4_chip_info },
1177 	{ .compatible = "adi,ad7386-4", .data = &ad7386_4_chip_info },
1178 	{ .compatible = "adi,ad7387-4", .data = &ad7387_4_chip_info },
1179 	{ .compatible = "adi,ad7388-4", .data = &ad7388_4_chip_info },
1180 	{ }
1181 };
1182 
1183 static const struct spi_device_id ad7380_id_table[] = {
1184 	{ "ad7380", (kernel_ulong_t)&ad7380_chip_info },
1185 	{ "ad7381", (kernel_ulong_t)&ad7381_chip_info },
1186 	{ "ad7383", (kernel_ulong_t)&ad7383_chip_info },
1187 	{ "ad7384", (kernel_ulong_t)&ad7384_chip_info },
1188 	{ "ad7386", (kernel_ulong_t)&ad7386_chip_info },
1189 	{ "ad7387", (kernel_ulong_t)&ad7387_chip_info },
1190 	{ "ad7388", (kernel_ulong_t)&ad7388_chip_info },
1191 	{ "ad7380-4", (kernel_ulong_t)&ad7380_4_chip_info },
1192 	{ "ad7381-4", (kernel_ulong_t)&ad7381_4_chip_info },
1193 	{ "ad7383-4", (kernel_ulong_t)&ad7383_4_chip_info },
1194 	{ "ad7384-4", (kernel_ulong_t)&ad7384_4_chip_info },
1195 	{ "ad7386-4", (kernel_ulong_t)&ad7386_4_chip_info },
1196 	{ "ad7387-4", (kernel_ulong_t)&ad7387_4_chip_info },
1197 	{ "ad7388-4", (kernel_ulong_t)&ad7388_4_chip_info },
1198 	{ }
1199 };
1200 MODULE_DEVICE_TABLE(spi, ad7380_id_table);
1201 
1202 static struct spi_driver ad7380_driver = {
1203 	.driver = {
1204 		.name = "ad7380",
1205 		.of_match_table = ad7380_of_match_table,
1206 	},
1207 	.probe = ad7380_probe,
1208 	.id_table = ad7380_id_table,
1209 };
1210 module_spi_driver(ad7380_driver);
1211 
1212 MODULE_AUTHOR("Stefan Popa <stefan.popa@analog.com>");
1213 MODULE_DESCRIPTION("Analog Devices AD738x ADC driver");
1214 MODULE_LICENSE("GPL");
1215