xref: /linux/drivers/iio/dac/ad3552r-hs.c (revision 746680ec6696585e30db3e18c93a63df9cbec39c)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Analog Devices AD3552R
4  * Digital to Analog converter driver, High Speed version
5  *
6  * Copyright 2024 Analog Devices Inc.
7  */
8 
9 #include <linux/bitfield.h>
10 #include <linux/debugfs.h>
11 #include <linux/delay.h>
12 #include <linux/gpio/consumer.h>
13 #include <linux/iio/backend.h>
14 #include <linux/iio/buffer.h>
15 #include <linux/mod_devicetable.h>
16 #include <linux/platform_device.h>
17 #include <linux/property.h>
18 #include <linux/units.h>
19 
20 #include "ad3552r.h"
21 #include "ad3552r-hs.h"
22 
23 /*
24  * Important notes for register map access:
25  * ========================================
26  *
27  * Register address space is divided in 2 regions, primary (config) and
28  * secondary (DAC). Primary region can only be accessed in simple SPI mode,
29  * with exception for ad355x models where setting QSPI pin high allows QSPI
30  * access to both the regions.
31  *
32  * Due to the fact that ad3541/2r do not implement QSPI, for proper device
33  * detection, HDL keeps "QSPI" pin level low at boot (see ad3552r manual, rev B
34  * table 7, pin 31, digital input). For this reason, actually the working mode
35  * between SPI, DSPI and QSPI must be set via software, configuring the target
36  * DAC appropriately, together with the backend API to configure the bus mode
37  * accordingly.
38  *
39  * Also, important to note that none of the three modes allow to read in DDR.
40  *
41  * In non-buffering operations, mode is set to simple SPI SDR for all primary
42  * and secondary region r/w accesses, to avoid to switch the mode each time DAC
43  * register is accessed (raw accesses, r/w), and to be able to dump registers
44  * content (possible as non DDR only).
45  * In buffering mode, driver sets best possible mode, D/QSPI and DDR.
46  */
47 
48 struct ad3552r_hs_state {
49 	const struct ad3552r_model_data *model_data;
50 	struct gpio_desc *reset_gpio;
51 	struct device *dev;
52 	struct iio_backend *back;
53 	bool single_channel;
54 	struct ad3552r_ch_data ch_data[AD3552R_MAX_CH];
55 	struct ad3552r_hs_platform_data *data;
56 	/* INTERFACE_CONFIG_D register cache, in DDR we cannot read values. */
57 	u32 config_d;
58 	/* Protects backend I/O operations from concurrent accesses. */
59 	struct mutex lock;
60 };
61 
62 enum ad3552r_sources {
63 	AD3552R_SRC_NORMAL,
64 	AD3552R_SRC_RAMP_16BIT,
65 };
66 
67 static const char * const dbgfs_attr_source[] = {
68 	[AD3552R_SRC_NORMAL] = "normal",
69 	[AD3552R_SRC_RAMP_16BIT] = "ramp-16bit",
70 };
71 
72 static int ad3552r_hs_reg_read(struct ad3552r_hs_state *st, u32 reg, u32 *val,
73 			       size_t xfer_size)
74 {
75 	/* No chip in the family supports DDR read. Informing of this. */
76 	WARN_ON_ONCE(st->config_d & AD3552R_MASK_SPI_CONFIG_DDR);
77 
78 	return st->data->bus_reg_read(st->back, reg, val, xfer_size);
79 }
80 
81 static int ad3552r_hs_set_data_source(struct ad3552r_hs_state *st,
82 				      enum iio_backend_data_source type)
83 {
84 	int i, ret;
85 
86 	for (i = 0; i < st->model_data->num_hw_channels; ++i) {
87 		ret = iio_backend_data_source_set(st->back, i, type);
88 		if (ret)
89 			return ret;
90 	}
91 
92 	return 0;
93 }
94 
95 static int ad3552r_hs_update_reg_bits(struct ad3552r_hs_state *st, u32 reg,
96 				      u32 mask, u32 val, size_t xfer_size)
97 {
98 	u32 rval;
99 	int ret;
100 
101 	ret = ad3552r_hs_reg_read(st, reg, &rval, xfer_size);
102 	if (ret)
103 		return ret;
104 
105 	rval = (rval & ~mask) | val;
106 
107 	return st->data->bus_reg_write(st->back, reg, rval, xfer_size);
108 }
109 
110 static int ad3552r_hs_read_raw(struct iio_dev *indio_dev,
111 			       struct iio_chan_spec const *chan,
112 			       int *val, int *val2, long mask)
113 {
114 	struct ad3552r_hs_state *st = iio_priv(indio_dev);
115 	int ret;
116 	int ch = chan->channel;
117 
118 	switch (mask) {
119 	case IIO_CHAN_INFO_SAMP_FREQ:
120 		/*
121 		 * Using a "num_spi_data_lanes" variable since ad3541/2 have
122 		 * only DSPI interface, while ad355x is QSPI. Then using 2 as
123 		 * DDR mode is considered always on (considering buffering
124 		 * mode always).
125 		 */
126 		*val = DIV_ROUND_CLOSEST(st->data->bus_sample_data_clock_hz *
127 					 st->model_data->num_spi_data_lanes * 2,
128 					 chan->scan_type.realbits);
129 
130 		return IIO_VAL_INT;
131 
132 	case IIO_CHAN_INFO_RAW:
133 		/* For RAW accesses, stay always in simple-spi. */
134 		ret = ad3552r_hs_reg_read(st,
135 				AD3552R_REG_ADDR_CH_DAC_16B(chan->channel),
136 				val, 2);
137 		if (ret)
138 			return ret;
139 
140 		return IIO_VAL_INT;
141 	case IIO_CHAN_INFO_SCALE:
142 		*val = st->ch_data[ch].scale_int;
143 		*val2 = st->ch_data[ch].scale_dec;
144 		return IIO_VAL_INT_PLUS_MICRO;
145 	case IIO_CHAN_INFO_OFFSET:
146 		*val = st->ch_data[ch].offset_int;
147 		*val2 = st->ch_data[ch].offset_dec;
148 		return IIO_VAL_INT_PLUS_MICRO;
149 	default:
150 		return -EINVAL;
151 	}
152 }
153 
154 static int ad3552r_hs_write_raw(struct iio_dev *indio_dev,
155 				struct iio_chan_spec const *chan,
156 				int val, int val2, long mask)
157 {
158 	struct ad3552r_hs_state *st = iio_priv(indio_dev);
159 	int ret;
160 
161 	switch (mask) {
162 	case IIO_CHAN_INFO_RAW:
163 		if (!iio_device_claim_direct(indio_dev))
164 			return -EBUSY;
165 		/* For RAW accesses, stay always in simple-spi. */
166 		ret = st->data->bus_reg_write(st->back,
167 			AD3552R_REG_ADDR_CH_DAC_16B(chan->channel),
168 			val, 2);
169 
170 		iio_device_release_direct(indio_dev);
171 		return ret;
172 	default:
173 		return -EINVAL;
174 	}
175 }
176 
177 static int ad3552r_hs_set_bus_io_mode_hs(struct ad3552r_hs_state *st)
178 {
179 	int bus_mode;
180 
181 	if (st->model_data->num_spi_data_lanes == 4)
182 		bus_mode = AD3552R_IO_MODE_QSPI;
183 	else
184 		bus_mode = AD3552R_IO_MODE_DSPI;
185 
186 	return st->data->bus_set_io_mode(st->back, bus_mode);
187 }
188 
189 static int ad3552r_hs_set_target_io_mode_hs(struct ad3552r_hs_state *st)
190 {
191 	u32 mode_target;
192 
193 	/*
194 	 * Best access for secondary reg area, QSPI where possible,
195 	 * else as DSPI.
196 	 */
197 	if (st->model_data->num_spi_data_lanes == 4)
198 		mode_target = AD3552R_QUAD_SPI;
199 	else
200 		mode_target = AD3552R_DUAL_SPI;
201 
202 	/*
203 	 * Better to not use update here, since generally it is already
204 	 * set as DDR mode, and it's not possible to read in DDR mode.
205 	 */
206 	return st->data->bus_reg_write(st->back,
207 				AD3552R_REG_ADDR_TRANSFER_REGISTER,
208 				FIELD_PREP(AD3552R_MASK_MULTI_IO_MODE,
209 					   mode_target) |
210 				AD3552R_MASK_STREAM_LENGTH_KEEP_VALUE, 1);
211 }
212 
213 static int ad3552r_hs_buffer_postenable(struct iio_dev *indio_dev)
214 {
215 	struct ad3552r_hs_state *st = iio_priv(indio_dev);
216 	struct iio_backend_data_fmt fmt = {
217 		.type = IIO_BACKEND_DATA_UNSIGNED
218 	};
219 	int loop_len, val, ret;
220 
221 	switch (*indio_dev->active_scan_mask) {
222 	case AD3552R_CH0_ACTIVE:
223 		st->single_channel = true;
224 		loop_len = 2;
225 		val = AD3552R_REG_ADDR_CH_DAC_16B(0);
226 		break;
227 	case AD3552R_CH1_ACTIVE:
228 		st->single_channel = true;
229 		loop_len = 2;
230 		val = AD3552R_REG_ADDR_CH_DAC_16B(1);
231 		break;
232 	case AD3552R_CH0_ACTIVE | AD3552R_CH1_ACTIVE:
233 		st->single_channel = false;
234 		loop_len = 4;
235 		val = AD3552R_REG_ADDR_CH_DAC_16B(1);
236 		break;
237 	default:
238 		return -EINVAL;
239 	}
240 
241 	/*
242 	 * With ad3541/2r support, QSPI pin is held low at reset from HDL,
243 	 * streaming start sequence must respect strictly the order below.
244 	 */
245 
246 	/* Primary region access, set streaming mode (now in SPI + SDR). */
247 	ret = ad3552r_hs_update_reg_bits(st,
248 					 AD3552R_REG_ADDR_INTERFACE_CONFIG_B,
249 					 AD3552R_MASK_SINGLE_INST, 0, 1);
250 	if (ret)
251 		return ret;
252 
253 	/*
254 	 * Set target loop len, keeping the value: streaming writes at address
255 	 * 0x2c or 0x2a, in descending loop (2 or 4 bytes), keeping loop len
256 	 * value so that it's not cleared hereafter when _CS is deasserted.
257 	 */
258 	ret = ad3552r_hs_update_reg_bits(st, AD3552R_REG_ADDR_TRANSFER_REGISTER,
259 					 AD3552R_MASK_STREAM_LENGTH_KEEP_VALUE,
260 					 AD3552R_MASK_STREAM_LENGTH_KEEP_VALUE,
261 					 1);
262 	if (ret)
263 		goto exit_err_streaming;
264 
265 	ret = st->data->bus_reg_write(st->back,
266 				      AD3552R_REG_ADDR_STREAM_MODE,
267 				      loop_len, 1);
268 	if (ret)
269 		goto exit_err_streaming;
270 
271 	st->config_d |= AD3552R_MASK_SPI_CONFIG_DDR;
272 	ret = st->data->bus_reg_write(st->back,
273 				      AD3552R_REG_ADDR_INTERFACE_CONFIG_D,
274 				      st->config_d, 1);
275 	if (ret)
276 		goto exit_err_streaming;
277 
278 	ret = iio_backend_ddr_enable(st->back);
279 	if (ret)
280 		goto exit_err_ddr_mode_target;
281 
282 	/*
283 	 * From here onward mode is DDR, so reading any register is not possible
284 	 * anymore, including calling "ad3552r_hs_update_reg_bits" function.
285 	 */
286 
287 	/* Set target to best high speed mode (D or QSPI). */
288 	ret = ad3552r_hs_set_target_io_mode_hs(st);
289 	if (ret)
290 		goto exit_err_ddr_mode;
291 
292 	/* Set bus to best high speed mode (D or QSPI). */
293 	ret = ad3552r_hs_set_bus_io_mode_hs(st);
294 	if (ret)
295 		goto exit_err_bus_mode_target;
296 
297 	/*
298 	 * Backend setup must be done now only, or related register values will
299 	 * be disrupted by previous bus accesses.
300 	 */
301 	ret = iio_backend_data_transfer_addr(st->back, val);
302 	if (ret)
303 		goto exit_err_bus_mode_target;
304 
305 	ret = iio_backend_data_format_set(st->back, 0, &fmt);
306 	if (ret)
307 		goto exit_err_bus_mode_target;
308 
309 	ret = iio_backend_data_stream_enable(st->back);
310 	if (ret)
311 		goto exit_err_bus_mode_target;
312 
313 	return 0;
314 
315 exit_err_bus_mode_target:
316 	/* Back to simple SPI, not using update to avoid read. */
317 	st->data->bus_reg_write(st->back, AD3552R_REG_ADDR_TRANSFER_REGISTER,
318 				FIELD_PREP(AD3552R_MASK_MULTI_IO_MODE,
319 					   AD3552R_SPI) |
320 				AD3552R_MASK_STREAM_LENGTH_KEEP_VALUE, 1);
321 
322 	/*
323 	 * Back bus to simple SPI, this must be executed together with above
324 	 * target mode unwind, and can be done only after it.
325 	 */
326 	st->data->bus_set_io_mode(st->back, AD3552R_IO_MODE_SPI);
327 
328 exit_err_ddr_mode:
329 	iio_backend_ddr_disable(st->back);
330 
331 exit_err_ddr_mode_target:
332 	/*
333 	 * Back to SDR. In DDR we cannot read, whatever the mode is, so not
334 	 * using update.
335 	 */
336 	st->config_d &= ~AD3552R_MASK_SPI_CONFIG_DDR;
337 	st->data->bus_reg_write(st->back, AD3552R_REG_ADDR_INTERFACE_CONFIG_D,
338 				st->config_d, 1);
339 
340 exit_err_streaming:
341 	/* Back to single instruction mode, disabling loop. */
342 	st->data->bus_reg_write(st->back, AD3552R_REG_ADDR_INTERFACE_CONFIG_B,
343 				AD3552R_MASK_SINGLE_INST |
344 				AD3552R_MASK_SHORT_INSTRUCTION, 1);
345 
346 	return ret;
347 }
348 
349 static int ad3552r_hs_buffer_predisable(struct iio_dev *indio_dev)
350 {
351 	struct ad3552r_hs_state *st = iio_priv(indio_dev);
352 	int ret;
353 
354 	ret = iio_backend_data_stream_disable(st->back);
355 	if (ret)
356 		return ret;
357 
358 	/*
359 	 * Set us to simple SPI, even if still in ddr, so to be able to write
360 	 * in primary region.
361 	 */
362 	ret = st->data->bus_set_io_mode(st->back, AD3552R_IO_MODE_SPI);
363 	if (ret)
364 		return ret;
365 
366 	/*
367 	 * Back to SDR (in DDR we cannot read, whatever the mode is, so not
368 	 * using update).
369 	 */
370 	st->config_d &= ~AD3552R_MASK_SPI_CONFIG_DDR;
371 	ret = st->data->bus_reg_write(st->back,
372 				      AD3552R_REG_ADDR_INTERFACE_CONFIG_D,
373 				      st->config_d, 1);
374 	if (ret)
375 		return ret;
376 
377 	ret = iio_backend_ddr_disable(st->back);
378 	if (ret)
379 		return ret;
380 
381 	/*
382 	 * Back to simple SPI for secondary region too now, so to be able to
383 	 * dump/read registers there too if needed.
384 	 */
385 	ret = ad3552r_hs_update_reg_bits(st, AD3552R_REG_ADDR_TRANSFER_REGISTER,
386 					 AD3552R_MASK_MULTI_IO_MODE,
387 					 AD3552R_SPI, 1);
388 	if (ret)
389 		return ret;
390 
391 	/* Back to single instruction mode, disabling loop. */
392 	ret = ad3552r_hs_update_reg_bits(st,
393 					 AD3552R_REG_ADDR_INTERFACE_CONFIG_B,
394 					 AD3552R_MASK_SINGLE_INST,
395 					 AD3552R_MASK_SINGLE_INST, 1);
396 	if (ret)
397 		return ret;
398 
399 	return 0;
400 }
401 
402 static inline int ad3552r_hs_set_output_range(struct ad3552r_hs_state *st,
403 					      int ch, unsigned int mode)
404 {
405 	int val;
406 
407 	if (ch == 0)
408 		val = FIELD_PREP(AD3552R_MASK_CH0_RANGE, mode);
409 	else
410 		val = FIELD_PREP(AD3552R_MASK_CH1_RANGE, mode);
411 
412 	return ad3552r_hs_update_reg_bits(st,
413 					  AD3552R_REG_ADDR_CH0_CH1_OUTPUT_RANGE,
414 					  AD3552R_MASK_CH_OUTPUT_RANGE_SEL(ch),
415 					  val, 1);
416 }
417 
418 static int ad3552r_hs_reset(struct ad3552r_hs_state *st)
419 {
420 	int ret;
421 
422 	st->reset_gpio = devm_gpiod_get_optional(st->dev,
423 						 "reset", GPIOD_OUT_HIGH);
424 	if (IS_ERR(st->reset_gpio))
425 		return PTR_ERR(st->reset_gpio);
426 
427 	if (st->reset_gpio) {
428 		fsleep(10);
429 		gpiod_set_value_cansleep(st->reset_gpio, 0);
430 	} else {
431 		ret = ad3552r_hs_update_reg_bits(st,
432 			AD3552R_REG_ADDR_INTERFACE_CONFIG_A,
433 			AD3552R_MASK_SOFTWARE_RESET,
434 			AD3552R_MASK_SOFTWARE_RESET, 1);
435 		if (ret)
436 			return ret;
437 	}
438 	msleep(100);
439 
440 	return 0;
441 }
442 
443 static int ad3552r_hs_scratch_pad_test(struct ad3552r_hs_state *st)
444 {
445 	int ret, val;
446 
447 	ret = st->data->bus_reg_write(st->back, AD3552R_REG_ADDR_SCRATCH_PAD,
448 				      AD3552R_SCRATCH_PAD_TEST_VAL1, 1);
449 	if (ret)
450 		return ret;
451 
452 	ret = st->data->bus_reg_read(st->back, AD3552R_REG_ADDR_SCRATCH_PAD,
453 				     &val, 1);
454 	if (ret)
455 		return ret;
456 
457 	if (val != AD3552R_SCRATCH_PAD_TEST_VAL1)
458 		return dev_err_probe(st->dev, -EIO,
459 			"SCRATCH_PAD_TEST mismatch. Expected 0x%x, Read 0x%x\n",
460 			AD3552R_SCRATCH_PAD_TEST_VAL1, val);
461 
462 	ret = st->data->bus_reg_write(st->back, AD3552R_REG_ADDR_SCRATCH_PAD,
463 				      AD3552R_SCRATCH_PAD_TEST_VAL2, 1);
464 	if (ret)
465 		return ret;
466 
467 	ret = st->data->bus_reg_read(st->back, AD3552R_REG_ADDR_SCRATCH_PAD,
468 				     &val, 1);
469 	if (ret)
470 		return ret;
471 
472 	if (val != AD3552R_SCRATCH_PAD_TEST_VAL2)
473 		return dev_err_probe(st->dev, -EIO,
474 			"SCRATCH_PAD_TEST mismatch. Expected 0x%x, Read 0x%x\n",
475 			AD3552R_SCRATCH_PAD_TEST_VAL2, val);
476 
477 	return 0;
478 }
479 
480 static int ad3552r_hs_setup_custom_gain(struct ad3552r_hs_state *st,
481 					int ch, u16 gain, u16 offset)
482 {
483 	int ret;
484 
485 	ret = st->data->bus_reg_write(st->back, AD3552R_REG_ADDR_CH_OFFSET(ch),
486 				      offset, 1);
487 	if (ret)
488 		return ret;
489 
490 	return st->data->bus_reg_write(st->back, AD3552R_REG_ADDR_CH_GAIN(ch),
491 				      gain, 1);
492 }
493 
494 static int ad3552r_hs_reg_access(struct iio_dev *indio_dev, unsigned int reg,
495 				 unsigned int writeval, unsigned int *readval)
496 {
497 	struct ad3552r_hs_state *st = iio_priv(indio_dev);
498 
499 	if (reg > st->model_data->max_reg_addr)
500 		return -EINVAL;
501 
502 	/*
503 	 * There are 8, 16 or 24 bit registers, but HDL supports only reading 8
504 	 * or 16 bit data, not 24. So, also to avoid to check any proper read
505 	 * alignment, supporting only 8-bit readings here.
506 	 */
507 	if (readval)
508 		return ad3552r_hs_reg_read(st, reg, readval, 1);
509 
510 	return st->data->bus_reg_write(st->back, reg, writeval, 1);
511 }
512 
513 static ssize_t ad3552r_hs_show_data_source(struct file *f, char __user *userbuf,
514 					   size_t count, loff_t *ppos)
515 {
516 	struct ad3552r_hs_state *st = file_inode(f)->i_private;
517 	enum iio_backend_data_source type;
518 	int idx, ret;
519 
520 	guard(mutex)(&st->lock);
521 
522 	ret = iio_backend_data_source_get(st->back, 0, &type);
523 	if (ret)
524 		return ret;
525 
526 	switch (type) {
527 	case IIO_BACKEND_INTERNAL_RAMP_16BIT:
528 		idx = AD3552R_SRC_RAMP_16BIT;
529 		break;
530 	case IIO_BACKEND_EXTERNAL:
531 		idx = AD3552R_SRC_NORMAL;
532 		break;
533 	default:
534 		return -EINVAL;
535 	}
536 
537 	return simple_read_from_buffer(userbuf, count, ppos,
538 				       dbgfs_attr_source[idx],
539 				       strlen(dbgfs_attr_source[idx]));
540 }
541 
542 static ssize_t ad3552r_hs_write_data_source(struct file *f,
543 					    const char __user *userbuf,
544 					    size_t count, loff_t *ppos)
545 {
546 	struct ad3552r_hs_state *st = file_inode(f)->i_private;
547 	char buf[64];
548 	int ret, source;
549 
550 	guard(mutex)(&st->lock);
551 
552 	ret = simple_write_to_buffer(buf, sizeof(buf) - 1, ppos, userbuf,
553 				     count);
554 	if (ret < 0)
555 		return ret;
556 
557 	buf[count] = '\0';
558 
559 	ret = match_string(dbgfs_attr_source, ARRAY_SIZE(dbgfs_attr_source),
560 			   buf);
561 	if (ret < 0)
562 		return ret;
563 
564 	switch (ret) {
565 	case AD3552R_SRC_RAMP_16BIT:
566 		source = IIO_BACKEND_INTERNAL_RAMP_16BIT;
567 		break;
568 	case AD3552R_SRC_NORMAL:
569 		source = IIO_BACKEND_EXTERNAL;
570 		break;
571 	default:
572 		return -EINVAL;
573 	}
574 
575 	ret = ad3552r_hs_set_data_source(st, source);
576 	if (ret)
577 		return ret;
578 
579 	return count;
580 }
581 
582 static ssize_t ad3552r_hs_show_data_source_avail(struct file *f,
583 						 char __user *userbuf,
584 						 size_t count, loff_t *ppos)
585 {
586 	ssize_t len = 0;
587 	char buf[128];
588 	int i;
589 
590 	for (i = 0; i < ARRAY_SIZE(dbgfs_attr_source); i++) {
591 		len += scnprintf(buf + len, PAGE_SIZE - len, "%s ",
592 				 dbgfs_attr_source[i]);
593 	}
594 	buf[len - 1] = '\n';
595 
596 	return simple_read_from_buffer(userbuf, count, ppos, buf, len);
597 }
598 
599 static const struct file_operations ad3552r_hs_data_source_fops = {
600 	.owner = THIS_MODULE,
601 	.write = ad3552r_hs_write_data_source,
602 	.read = ad3552r_hs_show_data_source,
603 };
604 
605 static const struct file_operations ad3552r_hs_data_source_avail_fops = {
606 	.owner = THIS_MODULE,
607 	.read = ad3552r_hs_show_data_source_avail,
608 };
609 
610 static int ad3552r_hs_setup(struct ad3552r_hs_state *st)
611 {
612 	u16 id;
613 	u16 gain = 0, offset = 0;
614 	u32 ch, val, range;
615 	int ret;
616 
617 	ret = ad3552r_hs_reset(st);
618 	if (ret)
619 		return ret;
620 
621 	/* HDL starts with DDR enabled, disabling it. */
622 	ret = iio_backend_ddr_disable(st->back);
623 	if (ret)
624 		return ret;
625 
626 	ret = st->data->bus_reg_write(st->back,
627 				      AD3552R_REG_ADDR_INTERFACE_CONFIG_B,
628 				      AD3552R_MASK_SINGLE_INST |
629 				      AD3552R_MASK_SHORT_INSTRUCTION, 1);
630 	if (ret)
631 		return ret;
632 
633 	ret = ad3552r_hs_scratch_pad_test(st);
634 	if (ret)
635 		return ret;
636 
637 	/*
638 	 * Caching config_d, needed to restore it after streaming,
639 	 * and also, to detect possible DDR read, that's not allowed.
640 	 */
641 	ret = st->data->bus_reg_read(st->back,
642 				     AD3552R_REG_ADDR_INTERFACE_CONFIG_D,
643 				     &st->config_d, 1);
644 	if (ret)
645 		return ret;
646 
647 	ret = ad3552r_hs_reg_read(st, AD3552R_REG_ADDR_PRODUCT_ID_L, &val, 1);
648 	if (ret)
649 		return ret;
650 
651 	id = val;
652 
653 	ret = ad3552r_hs_reg_read(st, AD3552R_REG_ADDR_PRODUCT_ID_H, &val, 1);
654 	if (ret)
655 		return ret;
656 
657 	id |= val << 8;
658 	if (id != st->model_data->chip_id)
659 		dev_warn(st->dev,
660 			 "chip ID mismatch, detected 0x%x but expected 0x%x\n",
661 			 id, st->model_data->chip_id);
662 
663 	dev_dbg(st->dev, "chip id %s detected", st->model_data->model_name);
664 
665 	/* Clear reset error flag, see ad3552r manual, rev B table 38. */
666 	ret = st->data->bus_reg_write(st->back, AD3552R_REG_ADDR_ERR_STATUS,
667 				      AD3552R_MASK_RESET_STATUS, 1);
668 	if (ret)
669 		return ret;
670 
671 	ret = st->data->bus_reg_write(st->back,
672 				      AD3552R_REG_ADDR_SH_REFERENCE_CONFIG,
673 				      0, 1);
674 	if (ret)
675 		return ret;
676 
677 	ret = ad3552r_hs_set_data_source(st, IIO_BACKEND_EXTERNAL);
678 	if (ret)
679 		return ret;
680 
681 	ret = ad3552r_get_ref_voltage(st->dev, &val);
682 	if (ret < 0)
683 		return ret;
684 
685 	val = ret;
686 
687 	ret = ad3552r_hs_update_reg_bits(st,
688 					 AD3552R_REG_ADDR_SH_REFERENCE_CONFIG,
689 					 AD3552R_MASK_REFERENCE_VOLTAGE_SEL,
690 					 val, 1);
691 	if (ret)
692 		return ret;
693 
694 	ret = ad3552r_get_drive_strength(st->dev, &val);
695 	if (!ret) {
696 		st->config_d |=
697 			FIELD_PREP(AD3552R_MASK_SDO_DRIVE_STRENGTH, val);
698 
699 		ret = st->data->bus_reg_write(st->back,
700 					AD3552R_REG_ADDR_INTERFACE_CONFIG_D,
701 					st->config_d, 1);
702 		if (ret)
703 			return ret;
704 	}
705 
706 	device_for_each_child_node_scoped(st->dev, child) {
707 		ret = fwnode_property_read_u32(child, "reg", &ch);
708 		if (ret)
709 			return dev_err_probe(st->dev, ret,
710 					     "reg property missing\n");
711 
712 		ret = ad3552r_get_output_range(st->dev, st->model_data, child,
713 					       &range);
714 		if (ret && ret != -ENOENT)
715 			return ret;
716 		if (ret == -ENOENT) {
717 			ret = ad3552r_get_custom_gain(st->dev, child,
718 						&st->ch_data[ch].p,
719 						&st->ch_data[ch].n,
720 						&st->ch_data[ch].rfb,
721 						&st->ch_data[ch].gain_offset);
722 			if (ret)
723 				return ret;
724 
725 			gain = ad3552r_calc_custom_gain(st->ch_data[ch].p,
726 						st->ch_data[ch].n,
727 						st->ch_data[ch].gain_offset);
728 			offset = abs(st->ch_data[ch].gain_offset);
729 
730 			st->ch_data[ch].range_override = 1;
731 
732 			ret = ad3552r_hs_setup_custom_gain(st, ch, gain,
733 							   offset);
734 			if (ret)
735 				return ret;
736 		} else {
737 			st->ch_data[ch].range = range;
738 
739 			ret = ad3552r_hs_set_output_range(st, ch, range);
740 			if (ret)
741 				return ret;
742 		}
743 
744 		ad3552r_calc_gain_and_offset(&st->ch_data[ch], st->model_data);
745 	}
746 
747 	return 0;
748 }
749 
750 static const struct iio_buffer_setup_ops ad3552r_hs_buffer_setup_ops = {
751 	.postenable = ad3552r_hs_buffer_postenable,
752 	.predisable = ad3552r_hs_buffer_predisable,
753 };
754 
755 #define AD3552R_CHANNEL(ch) { \
756 	.type = IIO_VOLTAGE, \
757 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
758 			      BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
759 			      BIT(IIO_CHAN_INFO_SCALE) | \
760 			      BIT(IIO_CHAN_INFO_OFFSET), \
761 	.output = 1, \
762 	.indexed = 1, \
763 	.channel = (ch), \
764 	.scan_index = (ch), \
765 	.scan_type = { \
766 		.sign = 'u', \
767 		.realbits = 16, \
768 		.storagebits = 16, \
769 		.endianness = IIO_BE, \
770 	} \
771 }
772 
773 static const struct iio_chan_spec ad3552r_hs_channels[] = {
774 	AD3552R_CHANNEL(0),
775 	AD3552R_CHANNEL(1),
776 };
777 
778 static const struct iio_info ad3552r_hs_info = {
779 	.read_raw = &ad3552r_hs_read_raw,
780 	.write_raw = &ad3552r_hs_write_raw,
781 	.debugfs_reg_access = &ad3552r_hs_reg_access,
782 };
783 
784 static void ad3552r_hs_debugfs_init(struct iio_dev *indio_dev)
785 {
786 	struct ad3552r_hs_state *st = iio_priv(indio_dev);
787 	struct dentry *d = iio_get_debugfs_dentry(indio_dev);
788 
789 	if (!IS_ENABLED(CONFIG_DEBUG_FS))
790 		return;
791 
792 	d = iio_get_debugfs_dentry(indio_dev);
793 	if (!d) {
794 		dev_warn(st->dev, "can't set debugfs in driver dir\n");
795 		return;
796 	}
797 
798 	debugfs_create_file("data_source", 0600, d, st,
799 			    &ad3552r_hs_data_source_fops);
800 	debugfs_create_file("data_source_available", 0600, d, st,
801 			    &ad3552r_hs_data_source_avail_fops);
802 }
803 
804 static int ad3552r_hs_probe(struct platform_device *pdev)
805 {
806 	struct ad3552r_hs_state *st;
807 	struct iio_dev *indio_dev;
808 	int ret;
809 
810 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*st));
811 	if (!indio_dev)
812 		return -ENOMEM;
813 
814 	st = iio_priv(indio_dev);
815 	st->dev = &pdev->dev;
816 
817 	st->data = dev_get_platdata(st->dev);
818 	if (!st->data)
819 		return dev_err_probe(st->dev, -ENODEV, "No platform data !");
820 
821 	st->back = devm_iio_backend_get(&pdev->dev, NULL);
822 	if (IS_ERR(st->back))
823 		return PTR_ERR(st->back);
824 
825 	ret = devm_iio_backend_enable(&pdev->dev, st->back);
826 	if (ret)
827 		return ret;
828 
829 	st->model_data = device_get_match_data(&pdev->dev);
830 	if (!st->model_data)
831 		return -ENODEV;
832 
833 	indio_dev->name = "ad3552r";
834 	indio_dev->modes = INDIO_DIRECT_MODE;
835 	indio_dev->setup_ops = &ad3552r_hs_buffer_setup_ops;
836 	indio_dev->channels = ad3552r_hs_channels;
837 	indio_dev->num_channels = ARRAY_SIZE(ad3552r_hs_channels);
838 	indio_dev->info = &ad3552r_hs_info;
839 
840 	ret = devm_iio_backend_request_buffer(&pdev->dev, st->back, indio_dev);
841 	if (ret)
842 		return ret;
843 
844 	ret = ad3552r_hs_setup(st);
845 	if (ret)
846 		return ret;
847 
848 	ret = devm_iio_device_register(&pdev->dev, indio_dev);
849 	if (ret)
850 		return ret;
851 
852 	ret = devm_mutex_init(&pdev->dev, &st->lock);
853 	if (ret)
854 		return ret;
855 
856 	ad3552r_hs_debugfs_init(indio_dev);
857 
858 	return ret;
859 }
860 
861 static const struct of_device_id ad3552r_hs_of_id[] = {
862 	{ .compatible = "adi,ad3541r", .data = &ad3541r_model_data },
863 	{ .compatible = "adi,ad3542r", .data = &ad3542r_model_data },
864 	{ .compatible = "adi,ad3551r", .data = &ad3551r_model_data },
865 	{ .compatible = "adi,ad3552r", .data = &ad3552r_model_data },
866 	{ }
867 };
868 MODULE_DEVICE_TABLE(of, ad3552r_hs_of_id);
869 
870 static struct platform_driver ad3552r_hs_driver = {
871 	.driver = {
872 		.name = "ad3552r-hs",
873 		.of_match_table = ad3552r_hs_of_id,
874 	},
875 	.probe = ad3552r_hs_probe,
876 };
877 module_platform_driver(ad3552r_hs_driver);
878 
879 MODULE_AUTHOR("Dragos Bogdan <dragos.bogdan@analog.com>");
880 MODULE_AUTHOR("Angelo Dureghello <adueghello@baylibre.com>");
881 MODULE_DESCRIPTION("AD3552R Driver - High Speed version");
882 MODULE_LICENSE("GPL");
883 MODULE_IMPORT_NS("IIO_BACKEND");
884 MODULE_IMPORT_NS("IIO_AD3552R");
885